عملکرد

Recently, the consumption of poultry meat, especially quail meat, has increased significantly due to some nutritional features, including high-quality protein and low fat content. This issue has led to an increase in the demand for the production of healthy products. Fat sources are one of the food items needed to provide energy in the poultry diet. Usually, mixed vegetable oils are used in commercial diets. Sesame oil has essential unsaturated fatty acids for poultry, which can have beneficial effects on the growth and health indicators of chickens. The main essential fatty acids in sesame oil include linoleic acid, oleic acid, palmitic acid, and stearic acid. The use of essential fatty acids in the diet of poultry increases their storage in meat and eggs, which can have beneficial effects on human health. Sesame oil contains compounds called lignans, such as sisamin, sisamulin, and small amounts of sisamol, and has many different physiological functions, such as reducing blood fat, reducing the level of arachidonic acid, increasing antioxidant capacity, increasing the bioavailability of gamma-tocopherol, and anti-inflammatory functions. On the other hand, sesame lignans can protect body cells from free radical damage by inhibiting reactive oxygen species. Sesame oil can increase the detoxification of chemicals in the liver and has a protective role against oxidative stress. Considering the antioxidant properties and nutritional compounds in sesame oil, the present study was conducted to investigate the effect of different levels of sesame oil and soybean oil on performance and growth indicators, as well as some serum biochemical parameters, including liver enzymes, profile fat, and proteins, in Japanese quail.

Three hundred quails (Japanese quail) with the age of 10 days were randomly divided into five treatments with three replications (20 quails in each replication) and fed with experimental diets for 42 days. All groups were reared in the same growing and management conditions until 42 days of age. In the experimental treatments, the base diet containing zero (control), 25, 50, 75, and 100% sesame oil was used instead of soybean oil. Growth indices (weight gain, feed consumption, and feed conversion ratio, FCR), the weight of internal organs (liver, heart, gizzard, breast, and thigh muscle), and some serum biochemical parameters were measured at the end of the growing period. Serum biochemical parameters included total protein, albumin, globulin, triglyceride, cholesterol, LDL (low-density lipoprotein), and HDL (high-density lipoprotein). The concentrations of blood parameters were measured by colorimetry (photometry) using commercial kits available in the market and based on the provided instructions. The data were statistically analyzed by SPSS version 22 statistical software with the one-way analysis of variance (ANOVA) test. Statistical analysis was performed at a 95% confidence level.

Feed consumption and FCR decreased by increasing the percentage of sesame oil replacement. The lowest feed consumption during the growing period belonged to the groups receiving 75 and 100% sesame oil, and the highest feed consumption was recorded in the group receiving 100% soybean oil; these two groups showed a significant difference (p < 0.05). No significant difference was seen in the feed consumption between the other groups. The weight gain of quails at the end of the rearing period was not affected by different levels of sesame oil replacement. The comparison of FCR in different treatments showed that the lowest FCR was found in quails fed with 75 and 100% sesame oil, and the highest FCR was seen in quails receiving 100% soybean oil (p < 0.05). There was no significant difference in FCR between the other groups. Different levels of sesame oil and soybean oil did not significantly affect the weight of the internal organs of the studied quails. Total protein, albumin, globulin, and the ratio of albumin to globulin were not significantly different in all groups. Increasing the percentage of sesame oil decreased triglycerides, cholesterol, and LDL and increased HDL. The triglyceride level in the groups receiving 75 and 100% sesame oil was significantly lower than in the quails of the control group and those fed with 25% sesame oil (p < 0.05). Cholesterol levels were significantly lower only in quails receiving 75 and 100% sesame oil than in the other groups (p < 0.05). The LDL level in quails receiving 25 and 50% sesame oil was higher than in those receiving 75 and 100% sesame oil (p < 0.05). HDL also increased with increasing the percentage of sesame oil replacement.

The results of this study showed that replacing sesame oil in the diet can have positive effects on the average daily feed intake and FCR. It seems that unsaturated fatty acids affect the digestibility and formation of fat micelles and lead to the improvement of metabolic energy efficiency, which affects the performance of quails. Furthermore, the addition of sesame oil to the diet improved serum biochemical indices, especially the lipid profile (triglyceride, cholesterol, LDL, and HDL). Probably, the sesamin present in sesame seeds reduces the activity and gene expression of enzymes involved in the synthesis of fatty acids and lipogenic enzymes and causes a decrease in liver fatty acid synthesis and ultimately the lipid profile. However, more studies should be considered to evaluate other effects of replacing this vegetable oil.

Cereal gains form the largest portion of the poultry industry. The most important cereal in this industry is corn grain, but the presence of some issues, including the change and fluctuation of corn prices accompanied by a shortage of corn gain in some conditions in our country, have forced poultry farmers to explore different substitutional grains, such as wheat. Compared with corn, wheat grain has some advantages over corn, including improving the pellet quality and having more crude protein along with higher lysine, methionine, arginine, phenylalanine, tryptophan, threonine, and valine. However, two drawbacks to wheat grain have limited its usage in poultry diets in some conditions. On the one hand, wheat has lower metabolizable energy than corn. On the other hand, non-starch polysaccharides in wheat grain prevent energy availability and impede the growth performance of boilers. The most prominent non-starch polysaccharide known in wheat is arabinoxylan, which includes almost 10% of this cereal; these particular polymers have a great water-holding capacity of around 10 times their weight. Furthermore, having arabinose in the lateral chain has made it possible for non-starch polysaccharides to become water-soluble. These factors make a high-viscosity condition in the gastrointestinal tract causing a low enzyme-substrate interaction, resulting in weaker digestion and absorption of starch, protein, and fat and, consequently, lower energy retention, which reduces the growth performance of birds. One of the most appropriate methods to improve broiler chickens' performance and decline the negative effects of non-starch polysaccharides (NSPs) in wheat is to apply multi-enzymes. The classic method for enzyme supplementation is to add enzymes over a formulated diet (over the top). Another way for enzyme addition is to consider the nutrient matrix values for the enzyme, which is the most suitable method to decrease the cost of both enzyme and feed consumption. The current study aimed to apply the nutrient matrix values for three different multi-enzymes and evaluate their effects on the performance, water consumption, litter moisture, jejunal viscosity, and some characteristics of the gastrointestinal tract in broilers fed wheat-soybean meal to find an appropriate criterion for the most realistic nutrient matrix values for enzymes.

Three-hundred-day-old male broiler chicks of commercial strain (Ross 308) were studied with four treatments, five replications, and 15 chicks in each replicate in a floor pen. All data were analyzed using a randomized complete design. The four dietary treatments consisted of a wheat-soybean meal-based diet without enzyme (control group) and three wheat-soybean-based diets supplemented with enzymes A, B, and C, which were added at 170, 600, and 500 mg/kg DM, respectively. The nutrient matrix values were considered for enzymes. The effects of treatments on the performance, carcass characteristics, length and weight of intestinal segments, digestive organs weight, water-to-feed intake ratio, and jejunal viscosity were investigated at the end of 42 days.

Results of this trial showed that in the starter, finisher, and the whole period, feed intake was not affected by enzyme addition whereas only in the grower period of rearing and only adding enzyme B to the wheat-soybean meal-based diet significantly improved Average Daily Feed Intake (ADFI) (p < 0.05). In the starter period, only the enzyme A addition to a wheat-based diet improved Average Daily Gain (ADG) (p < 0.05). However, in the grower, finisher, and the whole period, ADG was improved by enzyme A and B supplementation (p < 0.05). However, feed conversion ratio (FCR) was not affected by enzyme addition in the starter period (p > 0.05), but using nutrient matrix values for enzymes A and B significantly improved FCR in the grower, finisher, and in the entire period (p < 0.05). Results showed that enzyme supplementation did not significantly affect the relative weight of the pancreas, liver, relative weight and length of the duodenum, jejunum, ileum, and cecum, water to feed intake ratio, and litter moisture (p > 0.05). Birds that received enzyme A and B had lower jejunal content viscosity at day 23 and higher abdominal fat at day 42 (p < 0.05). While carcass yield and thigh relative weight did not change by enzyme supplementation (p > 0.05), breast relative weight for birds that received enzyme A was significantly lower than control treatment and the enzyme C containing group (p < 0.05), and there was no significant difference among enzymes A and B (p > 0.05).

The results of the present study showed that the application of nutrient matrix values for enzymes A and B improved the performance of broiler chickens fed a wheat-soybean meal-based diet, and their matrix values could be used for feed formulation to reduce the cost of each kilogram feed. Moreover, the results of the current study showed that using the nutrient matrix value for enzyme C did not significantly affect broiler performance. For assurance, more experiments are needed to be designed to evaluate the nutrient matrix value of this enzyme.

 In poultry breeding farms, density is one of the important factors in terms of welfare, production, and health in poultry. Density can be defined as the number of birds per unit area or kilograms per unit area. High density reduces body heat loss, bad air quality due to its improper exchange, increased ammonia level, and reduced access to food and water, which leads to reduced feed efficiency. It seems that the stress caused by high density can upset the balance of the microbial population of the digestive system. Improving the microbial population of the gastrointestinal tract through the addition of different sources of insoluble fiber may be beneficial for the development of the health and growth performance of broiler chickens grown at high densities. In Iran, rice hull is obtained as waste from rice grain processing, which contains a high percentage of insoluble fibers. Sunflower husks, as a byproduct, contain a significant amount of fiber. On the other hand, the sunflower hull is the outer covering of the sunflower seed. Sunflower hull and rice hull have high fiber and low energy. Considering the negative effects of high density and the positive impact of fibrous sources, the present study investigated the influence of different insoluble fiber sources on the performance and microbial population of the caecum in broiler chickens raised at high density.

 The experiment was performed with 390 one-day-old broiler chicks of Ross 308 strain in a completely randomized design with a 2×3 factorial arrangement and five replications. The experiment included two density levels (10 and 16 birds per square meter) and three fiber sources (diet without fiber, diet containing sunflower hull, and rice hull). Characteristics of feed intake, body weight gain, and feed conversion ratio were measured regularly and blood factors and bacterial counts were sampled on the last day after slaughter.

 There was no significant difference between the fiber source and density in different growing periods on average feed consumption and relative weight of different carcass components (P<0.05). High density resulted in a decrease in feed intake in the starter, finisher, and overall period compared to normal density (P<0.05). Birds fed with different fiber sources showed higher feed intake compared to the control treatment in the growth, finisher, and overall period of the experiment (P<0.05). Birds fed with a diet containing sunflower hull and rice hull in normal density conditions showed higher weight gain compared to other treatments in the final period. The best feed conversion ratio was observed in the rice hull treatment at the normal density level in the final and overall period of the experiment (P<0.05). Birds fed with sunflower hull in normal density and rice hull in high density showed a significant increase in blood HDL concentration compared to other treatments (P<0.05). Birds reared at high density showed significantly higher blood glucose, cholesterol, and LDL concentrations compared to birds reared at normal density (P<0.05). It may be the reason for the increase in LDL, glucose, and blood cholesterol concentration in high density, negative responses such as an increase in corticosterone level, an increase in lipid peroxidation, production of free radicals, and an increase in immunosuppression in chickens reared in high density. The interaction effect of fiber source and density level had no significant effect on Coliform and Escherichia coli populations in cecum (P<0.05). In the presence of sunflower hull and rice hull, high density led to a significant increase in the population of cecal Lactobacillus compared to normal density (P<0.05). In the absence of fiber, high density caused a significant decrease in the cecum Lactobacillus population compared to normal density (P<0.05). Diet is a major environmental factor that can directly affect the nature of the microbiota in the host.

 The results of this study showed that the use of fiber could improve the feed conversion ratio in high-density rearing conditions compared with birds fed a diet free of fiber and in normal-density rearing conditions. In addition, the use of sunflower hull and rice hull led to increased feed intake, weight gain, cecal Lactobacillus population, and improved feed conversion ratio in broiler chickens. Compared to birds reared at normal density, birds reared at high density showed a decrease in feed consumption, a decrease in weight gain, and an increase in the population of the cecal Coliform population.

The physical characteristics and nutrient balance of feed are among the most critical factors influencing animal health, performance, and feeding behavior of livestock. These factors not only have a direct impact on meeting the nutritional requirements of livestock but also play a key role in enhancing production efficiency, improving product quality, and mitigating nutrition-related diseases. This study aimed to evaluate the effects of feed physical form during late gestation and early lactation in ewes on blood metabolites, antioxidant status, and lamb performance after birth.

This study was conducted using 36 Mehraban breed ewes with an average body weight of 50.17±2.09 kg and an average age of three to four years in a completely randomized experimental design. The experimental treatments included: 1- mash concentrate, 2- pelleted concentrate, and 3- pelleted total mixed ration (TMR). Experimental treatments were provided to ewes during the last two months of pregnancy and the first month of lactation. To evaluate blood biochemical parameters and antioxidant status, blood samples were collected from the ewes at three times (30 days before lambing, day of lambing, and 30 days after lambing) before the morning feeding. Milk yield and milk fat content were also assessed on day 21 postpartum. Also, the performance of the lambs was evaluated by weighing them on the day of birth and weekly until the end of the trial.

The results indicated that feed intake during in the pre- and post-partum periods, as well as milk production, was higher in ewes fed with pelleted TMR and pelleted concentrate compared to those fed with mash concentrate (P<0.05), while the milk fat percentage was not affected by the experimental treatments. Feeding pelleted TMR and pelleted concentrate significantly increased serum glucose and urea concentrations (P<0.05), while other blood parameters, such as cholesterol, triglycerides, total protein, and liver enzymes, were not influenced by the experimental treatments. Also, feeding ewes with pelleted feed led to a significant reduction in malondialdehyde concentration and an increase in total antioxidant capacity at certain time points (P < 0.05), indicating a reduction in oxidative stress in animals fed this type of feed. In addition, body weight and daily weight gain of lambs were affected by the physical form of the feed consumed by the ewes at certain time points. Lambs born to ewes fed with pelleted TMR and pelleted concentrate had higher weight and daily weight gain between days seven and 30 of age than those born to ewes fed with mash concentrate (P<0.05). However, no significant difference was observed in lamb birth weight between different treatments.

Overall, the results of this study indicated that feeding ewes with pelleted TMR and pelleted concentrate during late pregnancy and early lactation can improve ewe performance, improve lamb performance, increase certain biochemical parameters, and enhance the antioxidant status of the ewes' blood. These findings emphasize the effective role of the physical form of feed as an effective tool in optimizing animal health, production performance, and welfare.

Newborn calves have special needs to accelerate their growth performance and improve their immune systems. Minerals are one of the most important metabolic improvers that can help the health of calves at overnutrition levels. Manganese is a necessary trace mineral that is a key ingredient in the metabolism of carbohydrates, lipids and, proteins, as well as playing an important role as a cofactor in the activity of several enzyme systems such as superoxide dismutase (MnSOD) activity, bone development (mucopolysaccharide synthesis) and blood cell regeneration. Manganese plays several important roles in the immune system, including its involvement in antioxidant pathways, its contribution to phagocytic activity, and its role in maintaining the structural integrity of epithelial barriers against infections. Manganese can be supplemented in both inorganic and organic forms, each with differing levels of bioavailability and absorption. Therefore, this study was conducted to investigate the impact of milk enrichment with manganese supplements, in both organic and inorganic forms, on the performance, biochemical and antioxidant parameters, and feeding behavior of suckling calves.  24 newborn calves were randomly divided into 3 groups with 8 replications. Experimental treatments include: 1) control group (without manganese supplementation), 2) Adding mineral manganese supplement to milk consumption and 3) Adding organic manganese supplements to milk consumption. The amount of manganese used in the milk of each calf was 30 mg per day. Manganese is dissolved in milk and consumed by calves. Calves were milked twice in the morning and evening and had free access to water and starter feed during the day. The length of the trial period was 63 days. Calves were weighed every 21 days. The amount of feed consumed and post-feed was recorded daily. To measure blood metabolites including biochemical parameters, concentration of blood elements, antioxidant status and activity of liver enzymes, blood samples were taken from calf vein on day 60. Finally, during the 61st to 63rd days of the experimental period, nutritional behaviors were measured for a duration of 48 hours. Data analysis was done using SAS statistical software version 9/1 (2004) and comparisons of means were done with Tukey's test at a significance level of 5 percent. The obtained results showed that the calves fed with milk enriched with manganese in organic and inorganic forms compared to the calves of the control group, a significant improvement in final weight, period weight gain, daily weight gain and dry matter consumption was observed. The use of organic and inorganic forms of manganese in the feeding of suckling calves did not have a significant effect on the feed conversion ratio of the calves. There was no significant effect on the amount of iron, zinc, copper, calcium and phosphorus of different treatments. The amount of plasma manganese in the treatment using organic manganese was associated with a significant increase compared to the treatment using inorganic manganese and the control treatment. The use of organic and mineral sources of manganese in the feeding of calves had no significant effect on triglyceride, cholesterol, urea, globulin and the ratio of albumin to globulin in the blood of calves. Organic and mineral sources of manganese increased the amount of glucose, total protein and albumin in the blood, so that the most significant increase was seen in the treatment of organic manganese users. Inorganic and organic forms of manganese did not cause significant changes in the amount of malondialdehyde, aspartate aminotransferase, and alkaline phosphatase in the blood of supplement consuming groups. In treatments using manganese, there was a significant decrease in total antioxidant status and a significant increase in the amount of catalase, superoxide dismutase, and alanine aminotransferase. The use of manganese supplement in organic and inorganic forms had no effect on the nutritional behaviors of calves such as milking, feeding, rumination, jaw rest, drinking water, unusual behavior, standing and lying down. Enriching milk with manganese supplement in organic and inorganic forms improved performance, weight gain, dry matter intake, total antioxidant status, and catalase and alanine aminotransferase and biochemical status in groups consuming milk containing manganese. Based on the results of this study, it is recommended to supplement the milk of newborn calves with 30 mg of organic manganese. Organic manganese showed improved effects on key parameters, including plasma manganese concentration, glucose levels, total protein, and superoxide dismutase (SOD) activity.

The various challenges that cows face in late pregnancy have lasting effects, affecting aspects of the calf's metabolism at birth and post-colostrum immunity. On the other hand, the increase in oxidative stress and excessive production of free radicals during the transfer period affects the growing fetus. This effect can alter the ability of calves to defend themselves against pathogens and cope with stressors, leading to changes in body weight, performance and skeletal development during the critical first month of life. Identifying and optimizing the effect of specific nutrients in the animal health program can be an efficient management strategy to reduce oxidative stress and inflammation associated with the transition period, followed by immune disorders and impaired health and growth of calves; In this regard, vitamins and minerals are known for their anti-inflammatory and anti-oxidative properties. Providing essential micronutrients to the mother during pregnancy is an effective way to meet the needs of the baby.

This experiment was conducted in order to investigate the effect of injecting minerals and vitamins in the late pregnancy of cows on performance, stool consistency, some blood metabolites, antioxidant status and skeletal growth indicators of their calves. For this purpose, 32 pregnant cows were selected based on the calving cycle, age, body weight and body condition score and were divided into 4 treatments and 8 repetitions in the form of a completely randomized design. Experimental treatments included: 1) control group (no vitamin and mineral supplement injection), 2) treatment receiving injectable vitamin supplement, 3) treatment receiving injectable mineral supplement and 4) treatment receiving vitamin and mineral supplement injection together. Supplements were injected 28 days before calving. After birth, calves born from each group were examined for 35 days. Blood samples were taken from calves at the end of the ex-perimental period (35 days after birth) to measure blood parameters.

The results showed that birth weight, day 35 weight, daily weight gain and total dry matter consumption of calves born from mothers receiving minerals, vitamins and minerals and vitamins were increased compared to the control group (P≥0.05). In the treatments receiving minerals, vitamins, and minerals and vitamins, an increase in colostrum IgG, IgG consumed by each calf, and serum IgG of calves was observed at birth and three days after birth (P≥0.05). Also, maternal injection of minerals and vitamins improved stool consistency and reduced the number of animals suffering from diarrhea; So that the best result was obtained from the simultaneous injection of minerals and vitamins (P≥0.05). On the other hand, the concentration of glucose, total protein and albumin of calves receiving maternal minerals, vitamins and minerals and vitamins were associated with a significant change compared to the control treatment (P≥0.05). Maternal injection increased the activity of glutathione peroxidase and decreased the total antioxidant status in calves compared to control calves (P≥0.05). The superoxide dismutase enzyme activity of calves born from the group receiving minerals and vitamins at the same time was associated with an increase, and the highest change in catalase activity was related to calves receiving treatment of minerals, and minerals and vitamins. In the calves born from the treatments receiving minerals, vitamins and minerals and vitamins, the height of the withers on the 28st day was increased compared to the control calves (P≥0.05).

In general, the simultaneous injection of minerals and vitamins to animals in the transition period before calving is recommended due to better performance and improvement of the immune system and health of their calves.

Insufficient minerals play a crucial role in various physiological functions such as digestive, and metabolic processes within the body. They act as cofactors in many enzymes and serve as catalysts in enzyme systems. These substances also contribute to the immune system and hormone secretion pathways (Tom et al., 2003). Zinc, copper, manganese, and iron are micro-elements that play essential roles in the growth, development, bone tissue formation, and immunity of broiler chickens (Echeverry et al., 2016; M'Sadeq et al., 2018). Zinc acts as an antioxidant, protecting cell membranes against peroxidation (Olivares et al., 2007). It also exhibits synergistic effects with vitamin E and polyphenols (Wołonciej et al., 2016). Copper is vital for growth, enzyme activity, and reproduction. It plays a significant role in various enzyme activities, such as ceruloplasmin, cytochrome oxidase, and superoxide dismutase, which help protect cells against oxidative stress (Hussein and Staufenbiel, 2012). Iron interacts with other elements, particularly copper, acting as a catalyst in oxidation reactions (Wołonciej et al., 2016). Manganese is also crucial for fetal growth, body weight gain, bone growth, and reproduction (Olgun, 2017).

To investigate the impact of different sources and levels of zinc, copper, manganese, and iron on the performance, blood parameters, and tibia characteristics of broiler chickens during the grower and finisher periods, 1250 broiler chickens from the Ross 308 strain were divided into 10 experimental treatments. Each treatment consisted of 5 replicates with 25 observations in a completely randomized design. The experimental treatments included mineral elements (zinc, copper, manganese, iron) from two organic and inorganic sources at levels of 40, 60, 80, 100, and 120% of the requirements during the grower and finisher periods. Blood samples were collected from two chicks in each replicate at 42 days of age and analyzed for various parameters at the laboratory of Razavi Hospital in Mashhad.

The effects of different levels of organic and inorganic minerals (zinc, copper, manganese, iron) on the performance of Ross 308 broiler chickens during the grower, finisher, and entire experimental periods are presented in Table 2. The results indicated significant effects of different treatments on body weight gain, feed consumption, and feed conversion ratio across all periods. The highest body weight gain during the grower period was observed in groups receiving 120%, 100%, and 80% of organic mineral requirements and 120% of inorganic requirements. Daily feed consumption was highest in the group receiving 40% of inorganic and organic mineral requirements and lowest in groups receiving 80%, 100%, and 120% of inorganic and 60%, 80%, 100%, and 120% of organic requirements. The feed conversion ratio was significantly higher in groups receiving 40% of organic and inorganic requirements compared to other groups during the grower period. In the finisher period, the highest daily body weight gain was observed in groups receiving 120%, 100%, 80% of organic mineral requirements and 120%, 100% of inorganic mineral requirements. Daily feed consumption was significantly lower in groups receiving 100%, 120% of inorganic mineral requirements and 120%, 100%, 80%, 60% of organic requirements during the finisher period. Throughout the rearing period (11-42 days), daily body weight gain was significantly higher in groups receiving 120%, 100% of organic mineral requirements and 120% of inorganic mineral requirements. Daily feed consumption was highest in the group receiving 40%, 60% of mineral requirements from inorganic sources.

The study results demonstrate that different sources and levels of recommended mineral requirements have significant effects on performance, bone mineral storage, and bone physical properties. The lowest feed conversion ratio during the entire rearing period was observed in groups receiving 80%, 100%, and 120% of the requirements from organic and mineral sources. Daily weight gain was significantly higher in groups receiving 100%, 120% of the recommended requirements of organic minerals compared to other groups. Zinc, copper, manganese, and iron stored in bones were significantly higher in groups receiving 80%, 100%, 120% of the recommended requirements of organic minerals and 100%, 120% of the recommended inorganic requirements. Fracture energy was significantly higher in groups receiving 120%, 100%, 80% organic and inorganic minerals. Based on the findings, it is recommended to use 80% of minerals in organic form due to its high storage capacity in the tibia bone and its ability to achieve performance similar to 100% and 120% of the requirements from organic and inorganic sources.

In this study thity-two new-born Holstein male and female calves (3-d-old) were randomly assigned to one of four treatments: 1) feeding whole milk (HM) in 2 times/d (2×; HM-2×), 2) feeding HM in 3 times/d (3×; HM-3×), 3) feeding waste milk (WM) in 2× (WM-2×); and 4) feeding WM in 3× (WM-3×). The lowest starter dry matter (DM) intake (pre-weaning and entire period), total DM intake and the highest average daily gain (ADG; post-weaning and entire period) and feed efficiency (FE) were was observed in WM-3× calves compared to other groups (P<0.05). Calves in WM-3× group had the highest hip height (weaning and the end of experiment), body weight (BW; the end of experiment) and body length (weaning and the end of experiment) compared to other groups (P<0.05). Based on the conditions of the present study, it can be concluded that feeding HM at 3× improved Holstein Dairy calves. Further researches are needed to evaluate these findings.

Sodium and chlorine deficiencies lead to a significant reduction in osmotic pressure, resulting in water loss, dehydration, and ultimately, a severe decrease in bird performance (Chen et al., 2023). Increased levels of chlorine and sodium also cause reduced voluntary feed intake, wet litter, interference with normal functions, and toxicity (Yu et al., 2022). The National Research Council recommends sodium and chlorine levels for optimal growth during the starter (0-21 days), grower (22-43 days), and finisher (43-56 days) phases as 0.2%, 0.15%, and 0.12%, respectively (NRC, 1994). The Ross 308 strain guide also suggests sodium and chlorine levels of 0.18%-0.23% during different rearing phases (Aviagen, 2022). While various reports address the effects of different chlorine and sodium levels in broiler chickens, the effects of the chlorine to sodium ratio in broilers have not been examined. The Ross 308 strain recommends a chlorine to sodium ratio between 1:1 and 1.3:1 (Aviagen, 2022). The Hy-Line strain recommends a chlorine to sodium ratio of 1:1 to 1.1:1 in hot seasons (Hy-Line, 2016). Aviagen's technical report also states that chlorine levels in the diet should not exceed 10% above the sodium levels (Kretzschmar-McCluskey et al., 2014). The Hubbard strain nutritional guide recommends a chlorine to sodium ratio range of 1.1:1 to 1.3:1 (Hubbard, 2022). The stimulatory role of sodium and chlorine on feed and water intake has been observed in previous studies (Wang et al., 2020; Yu et al., 2022; Chen et al., 2022). However, the potential role of the chlorine to sodium ratio on performance during the starter phase of broiler chicks has not yet been investigated. Therefore, this study aims to examine the effects of different chlorine to sodium ratios in the starter diet on performance, yolk sac absorption, carcass characteristics, crop filling, and behavioral observations in young broiler chicks.

A total of 420 one-day-old Ross 308 male broiler chicks were used in a completely randomized design with 5 treatments, 6 replicates, and 14 chicks per replicate. The experimental diets including: 1) starter diet with a chlorine to sodium ratio of 1:1, 2) starter diet with a chlorine to sodium ratio of 1.1:1, 3) starter diet with a chlorine to sodium ratio of 1.2:1, 4) starter diet with a chlorine to sodium ratio of 1.3:1, and 5) starter diet with a chlorine to sodium ratio of 1.4:1. The experimental diets were fed only from days 1 to 10. Average body weight gain, average feed intake, and feed conversion ratio (adjusted for mortality if observed) were calculated for the starter phase (1-10 days) and the entire period (1-30 days). Water consumption was monitored from days 1 to 7, and the water-to-feed consumption ratio was calculated for this period. Feed and water consumption behaviors were recorded at 3, 6, 12, 24, 48 and 72 hours after chick placement in each pen. Crop filling tests were conducted at 2, 4, 8, 24, and 48 hours after chick placement. On days 3 and 5 of the experiment, 2 chicks from each replicate were randomly selected and euthanized using carbon dioxide gas. They were then transported to the carcass separation facility for the dissection of carcass components and internal organs. Additionally, on days 3 and 5 of the experiment, the yolk sacs were separated and weighed using a high-precision scale with an accuracy of 0.001 grams. All data were analyzed using the ANOVA option of the general linear model of SAS software. Significant differences between treatment means were determined by Tukey's multiple range test. Differences in means were regarded as significant at P < 0.05. A polynomial regression analysis was also employed to predict the effect of the different chlorine to sodium ratios on various parameters tested.

The results of the present study showed that increasing the chloride to sodium ratio in the diet led to a linear increase in body weight gain during days 1-10 (P<0.01) and 1-30 (P<0.05). In line with the results of the present study, Chen et al. (2020) reported that chloride levels of 0.15%, 0.2%, and 0.25% resulted in linear and quadratic improvements in body weight gain. The observed increase in body weight with the higher chloride to sodium ratio in the present study can be attributed to increased feed and water intake (Yu et al., 2022). Additionally, increasing the chloride to sodium ratio also led to a linear increase in feed intake during the 1-10-day period (P<0.05). Wang et al. (2020) also observed that increasing the chloride level in the diet from 0.06% to 0.1%, 0.15%, 0.2%, and 0.25% led to linear and quadratic increases in feed intake in laying hens from 43 to 54 weeks of age. These researchers attributed the observed increase in feed intake following the increase in dietary chloride levels to the inhibition of the effect of metabolic alkalosis on feed intake (Wang et al., 2020). Carcass yield, relative weights of the liver, small intestine, spleen, pancreas (P<0.05), bursa (P<0.05), and cecum also increased linearly with an increase in the dietary chloride to sodium ratio at 5 days of age (P<0.01). Moreover, the residual yolk sac decreased significantly in a linear manner with an increase in the dietary chloride to sodium ratio during 3 (P<0.01) and 5 (P<0.05) days of age. One of the primary factors influencing yolk sac absorption is the motility and peristaltic movements in the small intestine (van Der Wagt et al., 2020). Yolk sac absorption depends on feed intake, as increased feed consumption accelerates peristaltic movements, stimulating the discharge and absorption of the yolk sac in the small intestine (Mikec et al., 2006). At 10 days of age, plasma concentrations of sodium and chloride increased linearly with an increase in the dietary chloride to sodium ratio (P<0.01), while the concentration of potassium decreased linearly (P<0.05).

In general, it can be concluded that increasing the chloride to sodium ratio in the starter diet stimulates feed intake, leading to faster yolk sac absorption, improved weight gain, and better organ development in young broiler chicks.

This study was conducted with the aim of investigating the use of different levels of wheat distillers dried grains with solubles (WDDGS) in feed with or without enzymes on performance, intestinal morphology and ileal digestibility of broiler chickens. For this purpose, 300 pieces of one-day-old male and female broilers of Ross 308 strain with an average one-day weight of 42 grams were used. This design was implemented as a factorial 3x2 in the form of a completely randomized design with 6 treatments and 5 replications. The experimental diets included three levels of WDDGS (0, 10 and 20%) with and without enzyme (125g per ton). The results showed that the use of 20% WDDGS reduced the feed consumption of the final period and the average of the entire period compared to the control treatment (P<0.05). The use of 10 and 20% WDDGS in the diet of broilers decreased the digestibility of dry matter compared to the treatment without WDDGS. Also, the 20% level of WDDGS reduced protein digestibility compared to the 10% level. The use of enzyme also increased protein digestibility significantly (P<0.05). Also, broiler chickens fed with a diet containing 20% WDDGS had lower hair height and greater crypt depth than the treatment without WDDGS, but the use of enzyme caused hair height. Finally, it can be concluded that the use of 10% level of WDDGS does not have a negative effect on performance.

Milk contains a relatively small amount of iron, and one of the most important negative aspects of milk nutrition is the occurrence of digestive diseases, such as diarrhea. Its iron concentration is in the range of 0.3-0.6 mg/kg. Calves are prone to iron deficiency. Iron is an essential component of hemoglobin, myoglobin, and several enzymes such as catalase, peroxidase, and cytochrome oxidase. In the early stages of life, calves do not have a functional rumen, and it seems that they are more like monogastric animals that must obtain the nutrients they need. They also suffer from a lack of immune systems. Therefore, this condition exposes them to critical challenges, mainly the risk of disease and death. Iron requirements of animals vary depending on their age, sex, and physiological stages. The iron requirement for calves is estimated to be around 100 ppm, and it is generally believed that young cows need more iron than mature animals. In most dairy farms, iron supplements are added to the diet from an inorganic source, which can undergo oxidation and react with other substances, thereby decreasing solubility. For the purposes of animal nutrition and increasing bioavailability, this research focuses on the use of chelates or preparations of protein iron. By using additives containing iron compounds, bioavailability can be increased by chelation, which consists of a double covalent bond of the metal with amino acids. To solve this problem, the desired elements should be added to the diets of livestock in the form of chelated supplements. This research was designed to investigate the effect of a chelated iron supplement containing organic acids and amino acids on the performance, digestibility of nutrients, feeding behaviors, and blood parameters of weanling calves.

Thirty-six newborn male calves (with an average weight of 35.1 ± 2.7 kg) were randomly divided into three groups with 12 replications. Experimental treatments were a control group (without iron supplementation), diets supplemented with 50 mg of chelated iron based on organic acids per calf per day, and diets supplemented with 50 mg of chelated iron based on amino acids per head of calf per day. First, all the calves were carefully examined to ensure their health and performance. The duration of the experiment was 63 days. Calves were weighed every 21 days, and the amount of consumed feed was recorded daily after 16 hours of starvation after feeding using a digital scale. The feed consumption of each animal was also calculated from the difference in the given diets and the remaining manger of each animal. The increase in the amount of feed given to the animals was determined based on the feed of each animal on the following day. The feed of the animal would increase if the animal left less than 10% feed on three consecutive days. Diets were adjusted based on NRC (NRC, 2001) completely mixed, and provided to the calves two times: 8 in the morning and 4 in the evening. Animals had free access to water. Calves were also milked twice in the morning and in the evening (at the rate of 10% of body weight). For the samples of digestibility, the samples of feed, residues, and feces were first collected from each animal on days 58 to 63 for 5 days. To measure blood metabolites, blood was sampled from the calf's jugular vein on day 63. Blood samples were transferred into anticoagulant-containing tubes. To prepare plasma, blood samples were centrifuged at 3000 rpm for 10 min, and plasma samples were transferred to -20 °C until analysis. During days 61 to 63 of the experimental period, nutritional behaviors, including eating, resting, chewing, standing, and ruminating activities, were measured visually for all animals every 5 min for 48 hours.

The calves receiving chelated iron supplements containing amino acids showed increases in final weight (P = 0.0496), total period weight (P = 0.0198), and daily weight (P = 0.0212) and a decrease in feed conversion ratio (P = 0.0413) compared to the control group and the treatment receiving chelated iron supplements containing the organic acids. There were no significant differences in dry matter and milk consumption among different treatments. Nutrient digestibility and feeding behaviors were not affected by experimental treatments. The consumption of iron supplements by calves in both chelated forms containing organic acids and amino acids increased the amount of blood iron (P = 0.0379), ferritin (P=0.0011), unsaturated iron binding capacity (P=0.0428), transferrin (P = 0.0331), red blood cells (P = 0.0333), hemoglobin (P = 0.0290), and hematocrit (P = 0.0001). Receiving chelated iron supplements decreased the total antioxidant index (P = 0.0001) and total iron binding capacity (P = 0.0001) compared to the control group.

According to the results of this research, it is recommended to provide chelated iron containing amino acids due to improving the performance of suckling calves.

The lack of vitamins and minerals, which are lost due to processing, in poultry feed is an important challenge for poultry breeding experts. These nutrients and bioactive substances must be preserved in the feed. Protection of nutrients and vitamins in nano form is one of the most effective ways for health and prevention of diseases in poultry. Folic acid (vitamin B9) is a cofactor of many enzymes, and improper storage conditions or heat from cooking is a factor of its destruction. Due to its antioxidant properties, folic acid oxidizes quickly and has a short shelf life. However, folic acid fortification is the most efficient means of increasing dietary folate intake due to the low intake of folate-rich foods and the excessive loss of folate during processing. Therefore, it is very important to protect this vitamin in the diet. Existing methods to protect nutrients or active ingredients include microencapsulation, spray drying, extrusion encapsulation, fluidized bed coating, conjugation, nanoliposome, and hydrogel encapsulation. Nowadays, the increasing growth of new technologies (nanotechnology) as one of the important sciences in this era, has entered all dimensions and fields of animal, plant, and environmental life and has opened new horizons on the edge of natural sciences. All the physicochemical properties of the material change by changing particle size from micrometer to nanometer (one billionth of a meter) due to the increase in the surface-to-volume ratio. One of the most important methods available to preserve nutrients is the nanoliposome method. Nanoliposomes can usually range from tens of nanometers to several microns. Therefore, this research aimed to investigate the effect of folic acid nanoliposome and folic acid on blood biochemical metabolites and microbial population in the ileum of Ras 308 male broiler chickens.

This study was conducted as a 2 × 2 factorial experiment in a completely randomized design with 250 one-day-old broiler chicks in five treatments with five replicates and 10 observations per replicate. The treatments were a control diet, a folic acid-free diet supplemented with folic acid (4 mg/L of water) in non-nano form, a folic acid-fre diet supplemented with folic acid (4 mg/L of water) in nano form, a control diet supplemented with folic acid (4 mg/L of water) in non-nano form, and a control diet supplemented with folic acid (4 mg/L of water) in nano form. Carcass characteristics, malondialdehyde (MDA) concentration, and bird performance were periodically evaluated during the experiment.

Folic acid and nanoliposome folic acid did not significantly affect feed intake, weight gain, and feed conversion ratio (FCR) in the initial period. However, weight gain significantly influenced the interaction effects of folic acid and nanoliposome folic acid compared to the control diet. The addition of folic acid during the growth period significantly increased the weight of broiler chickens (p < 0.05), with a greater increase in folic acid nanoliposome treatment than in the other treatments. The interaction effects of folic acid and folic acid nanoliposome in the growing and finishing periods were significant on feed intake, weight gain, and FCR (p < 0.05). In the growing and final periods, feed intake, weight gain, and FCR increased significantly in the folic acid-free control diet in water (4 mg/L) in the folic acid nanoliposome form compared to the other treatments (p < 0.05). The lowest feed intake, weight gain, and FCR were measured in the control treatment in the growth and final periods compare d to the other treatments. Breast weight increased significantly in the control diet treatment with folic acid in water (4 mg/L) in the folic acid nanoliposome form (p < 0.05). The effect of folic acid was significant on some biochemical parameters, such as protein, albumin, and globulin, compared to the control treatment (p < 0.05). However, nano folic acid significantly increased protein, albumin, globulin, and uric acid (p < 0.05). Therefore, the highest significant amounts of total serum protein, albumin, and globulin belonged to the control diet treatment with the nano form folic acid in water (4 mg/L) (p < 0.05). Cholesterol and glucose concentrations significantly affected the interaction effects of folic acid and folic acid nanoliposome compared to the control diet. Abdominal fat and triglyceride decreased significantly in the control diet treatment with folic acid in water (4 mg/L) in the folic acid nanoliposome form (p < 0.05). However, the highest percentage of abdominal fat and triglycerides were observed in the control treatment. Although normal folic acid and folic acid nanoliposome and their interactions did not significantly influence MDA concentration,, folic acid nanoliposome positively affected the average MDA concentration. Normal folic acid and folic acid nanoliposomes did not significantly affect the microbial population of the ileum.

The results of this study showed that encapsulating folic acid in the growth and final periods improved performance, increased breast weight, and decreased abdominal fat.

Castration is one of the management activities practiced worldwide in order to reduce aggressive behaviour, sexual activity and to facilitate management ease. Numerous studies have been conducted comparing production efficiencies and carcass traits of intact and castrated beef cattle and sheep. It has been agreed generally that castration causes less growth efficiency and produces carcasses with higher fat contents which results in increased proportion of saturated fatty acids. However, effects of castration on mentioned parameters in goats has been less investigated, despite the fact that goats genetically deposit less fat in their muscles with a more favorable fatty acid composition compared with other ruminants. Therefore, this research was conducted to evaluate the effects of castration on growth performance and carcass and meat quality attributes in Markhoz kids.

Sixteen male Morkhoz kids (13.2±1.6 kg live body weight, 3 months old) were used to evaluate the effects of castration on growth performance, carcass and meat quality attributes and fatty acid composition of longissimus thoracis and semimembranosus muscles based on a completely randomized design with 2 treatments and 8 replicates. Kids were castrated using ring castration in the respective treatment one week before the beginning of the experimental period. During 119 days of feeding experimental diet (formulated to meet NRC recommendations for small ruminants), growth performance of kids were recorded individually. Then, all kids were slaughtered and enough samples of each muscle were collected from the left side of each carcass, vacuum-packed and frozen at −20°C until subsequent determination of meat quality attributes including shear force, cooking loss, colour, proximate composition and fatty acids profile. The value of pH24, percentages of drip loss and water holding capacity were determined immediately on the day after slaughtering.

Morkhoz kids castration decreased average daily feed intake and daily weight gain and increased feed conversion ratio significantly (P<0.05). However, cold carcass percentage, back fat thickness and rib eye area were not affected by castration. Fat percentage of longissimus thoracis and semimembranosus muscles increased significantly in response to castration (P<0.05), but crude protein content of muscles was similar in intact and castrated kids. Meat quality attributes of mentioned muscles, including pH24, drip loss, water holding capacity and shear force were not affected by castration; however, cooking loss percentage in longissimus thoracis muscle decreased significantly by castration (P<0.05). L* and b* indexes of meat colour showed similar values in both muscles of intact and castrated groups, but the value of a* index was significantly lower in muscles of castrated kids (P<0.05). Castration had no significant effect on fatty acid composition of intramuscular fat in the longissimus thoracis muscle and only minor effects on the fatty acid composition of semimembranosus muscle were observed, including significant reduction in C14:1 cis and C18:3 cis3 fatty acids percentages (P<0.05).

Results showed that Morkhoz kids castration, in addition to diminution of growth performance and feed efficiency, increase fat content of muscles which is not a desirable change with respect to consumers’ health.

In broilers, dietary fiber stimulates the production of hydrochloric acid and bile acids and improves amylase activity, leading to better nutrient utilization (Hetland et al., 2002). A well-developed gizzard also enhances reverse peristalsis, which churns food back up the digestive tract. A reduced-crude protein (CP) diet are typically formulated by decreasing soybean meal and increasing feed grains (such as maize or wheat), along with higher inclusions of non-bound (crystalline and synthetic) amino acids to meet nutritional requirements. Studies (Van Harn et al., 2017) have shown that CP reductions (20-30 g/kg) in Ross 308 broiler diets can be achieved without compromising live weight gain or feed intake. Notably, these diets even show a significant improvement in feed conversion ratio (FCR) with a 3.5% decrease. Dietary fiber with increased particle size may enhance foregut development more effectively in poultry fed diets moderately low in crude protein. This study investigates the performance of broilers fed on low-density crude protein diets with increasing particle size of sunflower (Helianthus annus L.) hulls. This experiment aimed to examine the effect of sunflower hull particle size on the performance and physiological response of broiler chickens fed with different protein levels. A completely randomized design based on a 3 × 2 factorial arrangement, comprising 6 treatments (6 replicates per treatment, 10 birds per replicate). The treatments included 3 types of dietary sunflower hull types (without hulls, 4% with 1 mm particle size, and 4% with 5 mm particle size) and 2 crude protein (CP) levels (normal and a 10% reduction). Feed intake (FI) and body weight gain (BWG) were recorded, and the feed conversion ratio (FCR) was calculated. To determine ideal nutrient digestibility, chickens were fed 3 g/kg of chromium oxide from days 21 to 25. On day 25, ileum contents from 2 birds per replicate were collected and stored at -20°C. The cecal microbial population was assessed at 42 days of age. Data were analyzed using SAS software and the GLM procedure. Duncan's multiple range test was used for mean comparison at a 5% significance level. The results indicated that incorporating sunflower hulls (SFH) in the diet increased FI, except during the starter period, and improved FCR in both the starter and grower periods. The high amount of FI in the treatments containing SFH may be related to the high level of lignin and cellulose, because it increases the rate of passage of digestive juice through the digestive tract and ultimately increases FI (González-Alvarado et al., 2010). Broilers fed coarse SFH showed increased relative weights of the carcass, gastrointestinal tract, gizzard. The use of a rich source of insoluble fiber in the diet can increase the growth of the digestive system, especially provetriculus and gizzard (Jimenez-Moreno et al., 2013). The apparent digestibility of crude protein improved by coarse SFH with low crude protein. The positive effect of fiber on the digestibility of raw protein can be attributed to the increase in pepsin activity and the increase in hydrochloric acid production (Gabriel et al., 2003). Both fine and coarse SFH in the diet enhanced the Lactobacillus population. Similarly, other researchers also reported that feeding broiler chickens with dietary lignocellulose leads to an increase in the presence of Lactobacillus species (Bogusławska-Tryk et al., 2015). Overall, the study results indicate that adding coarse sunflower hulls to the diet can enhance broiler growth performance. This improvement is achieved by increasing the digestibility of crude protein, as well as boosting the Lactobacillus population. Additionally, using coarse sunflower hulls led to an increase in the relative weight of the carcass and thighs.

This experiment was conducted to investigate the effect of extracted peptides from sunflower seed meal on performance, carcass characteristics, and antioxidant activity in broiler chickens. In this experiment, 200 Ross 308 male broiler chicks were used in a completely randomized design with five treatments, four replicates, and 10 chicks per each replicate, for 26 days. Experimental treatments included: 1) Control diet without any additives, 2) Control diet + 300 mg vitamin E per kg diet, 3) Control diet + 250 mg sunflower seed meal peptides per kg diet, 4) Control diet + 500 mg sunflower seed meal peptides per kg diet, 5) Control diet + 1000 mg sunflower seed meal peptides per kg diet. There were significant differences between treatments for feed conversion ratio and body weight gain in grower (days 11-26)and whole periods(days 1-26) of the experiment (p<0.05). The most, and least body weight gain belonged to treatment 5, and control treatment. Treatment 5 showed  least feed conversion ratio in grower and whole period (1.37 and 1.36) respectively (p<0.05). The effect of experimental treatments on carcass percentage was significan and highest carcass percentage belonged to treatment 5 (73.31%), and the lowest was observed in treatment 2 (68.37%) (p<0.05). The malondialdehyde concentration in breast and thigh meat treatments  received different levels of peptides and also treatment 2 was lower than the control treatment. In conclusion, results of the present experiment, showed that use of sunflower seed meal peptides have antioxidant activity and can improve performance, increase carcass quality, and meat stability during storaging through decreasing fat oxidation.

Using of antibiotics as promoters of growth has widely been prohibited in animal nutrition, because antibiotic resistance has become a major clinical and public health problem. This issue has caused researchers to look for a suitable alternative to antibiotics in animal nutrition, among which probiotics and plant additives can be mentioned. Licorice with the scientific name Glycyrrhiza glabra and the English name licorice, is a perennial plant from the legume family. Licorice root has various compounds, one of which is glycyrrhizin, which is about 50 times sweeter than sugar. In several studies, licorice plant has been used as a supplement in combination with other plants and secondary plant compounds as a feed additive in suckling calves and sheep. However, the use of licorice alone in animal diets has rarely been investigated, therefore, the aim of this study was to investigate the effect of using different levels of licorice root powder (LRP) on the performance, weaning age and weight, blood cells and skeletal growth indicators of Holstein suckling calves. In this experiment, 30 Holstein calves (15 males and 15 females) from three days to two weeks after weaning with an average weight of 40±1.9 kg were used with 3 treatments and 10 replications as a factorial trial in a completely randomized design. Starter diets containing 0, 2.5 and 5% LRP (replaced with wheat bran). Calves had free access to diet and fresh water all times. The weaning criteria was to consume 1 kg of starter per day for 3 consecutive days, and then the calves were gradually weaned during 4 days. The measured traits were dry matter intake (DMI), daily weight gain (DWG), feed conversion ratio, weaning age, feces consistency, skeletal growth indicators and blood cells. Daily DMI was measured with a digital scale. Feces consistency was checked by visual evaluation method. From birth to the end of the experiment the calves were weighed every week with a digital scale. Calves were examined every week in terms of skeletal growth parameters. Blood samples were taken from the calves on three times (three and six weeks old and two weeks after weaning). The DMI in calves fed diets containing LRP was significantly higher than the control group (P<0.05). The DMI in the entire period of experiment was 738.7 g/d with 5% LRP and 538 g/d with control diet. The DWG in before and after weaning was affected by the treatments, and the calves fed with starter diets containing LRP had a higher DWG than the control group (P<0.05). Compared to the control group, the calves fed experimental diets with LRP had a lower weaning age (P<0.05). The weaning age in calves fed with LRP was about 10 days lower than the control group. The effect of experimental diets on the feces consistency and skeletal growth parameters of calves was not significant. Blood cells, including the number of RBC, platelets, WBC, and the percentage of lymphocytes, granulocytes, and monocytes, and blood hemoglobin concentration are not affected by feeding with starter diets. The results showed that the addition of LRP in the starter diet of Holstein dairy calves increases DMI and weaning weight, improves performance and decreases weaning age, and therefore it can be used 5% LRP to improve the nutritional system in calves.

Recently, the inclusion of phytogenic feed additives in poultry for the purpose of supplementing gut health and positively impacting performance has received a great deal of attention and concern. Thyme is used in poultry nutrition in the form of herbal feed additive as it is known that its contents, such as thymol and carvacrol, have a positive impact on broiler performance and feed utilization, which in turn results in enhanced economic profits. This improvement in performance can be attributed to activation of the digestive system structure and function which causes an enhanced absorption and metabolism of the nutrient supplement and its ability to alter the gut microbiota.  Formulating diets based on ideal protein concept aim to reduce total N-excretions and ammonia emissionswhile meeting the nutritional needs of the animals. Poultry needs a specific quantity and balance of essential amino acids and nitrogen (for synthesis non-essential amino acids, NEAA) rather than crude protein. Chickens fed the standard levels of dietary protein can synthesize NEAA from excess essential amino acids. However, when low-protein diets are used, less EAA is available for NEAA synthesis. Reducing dietary protein in broiler feed is not a new subject. However, it is revealed that only few trials covered an entire production cycle with several feeding phases while majority of experiments focused on one phase only. Thyme improve protein afficiency

in this experiment, the effect two levels of Zataria multifolra (0 and 0.5 %) and two protein levels (100 (CP100) and 95 (CP95) % of Ross-308 broiler chickens’ requirement) on growth performance, physiological responses and meat quality were studied. In a completely randomized design with 2×2 factorial arrangement, 280 Ross-308 broiler chickens (one-d-old, mixed sexes) were allocated to 4 treatments, 5 replicates and 14 birds in each replicate. Growth performance, immune response, blood metabolites, blood cell count, meat quality and jejunum morphometry were considered.

Feed intake, BW and FCR of finisher and total period of production, carcass parameters except abdominal fat percentage were not affected by thyme poweder, protein levels or their interaction (P > 0.05) while inclusion of thyme powder on CP100 diet improved BW and BWG of broiler chickens during starter and grower periods (P<0.05). Inclusion of thyme powder on CP95 diet decreased serum cholesterol and LDL-cholesterol and increased HDL concentration. Feeding CP95 diet contatining 0.5 thyme poweder led to increase total protein concentration and decreased liver enzymes activity (P < 0.05). Also, feeding CP95 diet containing thyme powder decreased heterophile but increased lymphocyte count (P<0.05). Dietary treatments had no significant effects on humoral immune response, relative weight of lymphoid organs, breast and thigh meat pH and color, and jejunum morphometry.

In conclusion, apart from addition of thyme powder, 5 percent protein dilution in this experiment had no negative effects on growth performance, immune response and meat quality of broiler chickens and it maybe suggestible for broiler chickens.

Minerals play a crucial role in maintaining the characteristics of the rumen environment in cattle, enhancing the fermentation process. Selenium, a rare yet essential mineral, is particularly important for improving immunity and reducing the incidence of certain diseases. By contributing to the structure of the enzyme glutathione peroxidase, selenium is vital for the antioxidant system. This study aimed to compare the effects of selenium-enriched probiotic supplements on the growth performance, feed intake, hematological parameters, and health status of suckling calves. For this purpose, a total of 80 newly born Holstein calves (35±1 kg) were selected immediately after birth and before the first milk feeding. They were randomly assigned to four treatment groups. Each treatment group received one of the following diets randomly: the first group served as the control group and received a starter without selenium supplementation. The second, third, and fourth groups received probiotics enriched with selenium at concentrations of 0.15, 0.30, and 0.45 ppm, respectively (SE0.15, SE0.3, and SE0.45). The feeding period, based on the dairy farming schedule and the feeding period for each treatment, was considered 75 days mixed in the starter. Throughout the experimental period, growth-related parameters such as average weight gain, height, average daily dry matter intake, as well as the health condition of the calves were evaluated by evaluating the health of the calves using the Wisconsin scoring index were recorded. The results of this experiment indicated that the SE0.45 treatment, which received a starter supplemented with 0.45 ppm selenium-enriched probiotic, exhibited a higher average weight compared to the control group (linear and quadratic, P<0.05). The experiment also demonstrated that selenium supplementation led to an improvement in average feed intake during the trial period, with SE0.45 treatment showing the best performance compared to the control group (linear and quadratic, P<0.05). According to the reported results in Table 7, the blood albumin concentration in the selenium-supplemented treatment groups was higher than that in the control group (linear, quadratic, and cubic, P<0.05). Additionally, the average concentration of glutathione peroxidase in the selenium-receiving treatment groups was higher than in the control group (linear, P<0.05). The results of this experiment indicated that adding selenium-enriched probiotics at levels of 0.30 and 0.45 ppm to the diet of suckling calves resulted in an increase in average height at the end of the experimental period compared to the control group (linear and quadratic, P<0.05). The daily height gain of the calves in the selenium-receiving groups was higher than the control group before weaning (linear, quadratic, and cubic, P<0.05). Microbial culture results of fecal samples indicated that the total bacterial count in the 0.45 ppm selenium-supplemented group was lower than that in the control group (linear, P<0.05). However, the population of Lactobacillus species in this treatment group was higher than in the control group (linear and quadratic, P<0.05). The addition of selenium to the diet of suckling calves not only affected height and weight gain but also improved the antioxidant system in the blood and enhanced the intestinal microflora conditions of the calves. Based on the regression results obtained, the optimal selenium supplement dose in the diet of suckling calves until weaning was calculated to be between 0.11 to 0.41 ppm. The average optimal doses obtained for all significant traits are equivalent with 0.3 ppm on selenium in the supplement.

The effect of utilization of feed disinfected with ozone gas on performance, carcass characteristics and blood parameters of broilers was investigated using 432 Ross 308 male broilers in a 3×2 factorial arrangement with three levels of ozone gas (zero, 20, and 30 parts per million) and two levels of fat including low (1.5 and 2% vegetable oil for grower and finisher periods, respectively) and high (3 and 4% of vegetable oil for grower and finisher periods, respectively) in a completely randomized design with 6 treatments and 4 replications of 18 birds in each. At 42 days of age, two birds were selected from each replication and slaughtered after weighing and the weights of the carcass, heart, liver, small intestine, and ceca were measured precisely. The results showed that the weight gain of chicks fed a high-fat, ozone-free diet was significantly higher than that of chicks fed a high-fat, gassed with a 20 ppm ozone diet (P <0.05). The ceca weight of chicks fed low-fat diets was higher than that of birds fed high-fat diets and birds fed diets gassed with 20 ppm ozone had higher ceca weight (P <0.05). According to the results of this experiment, it seems that the utilization of ozone gas for the disinfection of diets containing high levels of fat has a negative effect on feed quality and reduces the performance of broilers.