فصلنامه پژوهشهای علوم دامی ایران
سال پانزدهم شماره 3 (پاییز 1402)

 Pomegranate has many secondary metabolites such as tannins and phenolic compounds, which have various properties such as antimicrobial, antioxidant, anti-inflammatory, and immune system stimulating effects. The amount of tannin in pomegranate skin has been reported up to 20.6%. The limiting effects of tannins can be related to reducing the use of nutrients, especially protein, reducing growth and performance, reducing palatability and feed consumption, and reducing the activity of digestive enzymes. In addition to the anti-nutritional effects in high concentration, the positive impact of dense tannins in optimal concentration includes improving live weight gain, preventing flatulence, increasing milk production, reducing intestinal nematodes, and reducing the production of NH3-N and methane in the rumen. Therefore, the present experiment was carried out to improve the nutritional value of pomegranate peel as a tannin-containing edible material by treating it with some tannase-producing bacteria for ruminants.

 Pomegranate peel was treated with tannin-degrading bacteria including Klebsiella pneumoniae and Acinetobacter (isolated from deer rumen), Lactobacillus fermentum (isolated from Najdi goat rumen), and commercial Lactobacillus fermentum, and its nutritional value including chemical composition, digestibility, and fermentation ability alone (first experiment) or as a combination in a standard fattening lamb diet (second experiment), with two-stage digestion method and gas production test were studied. In the first experiment, five experimental treatments included 1- Pomegranate peel without treatment (control treatment), treatment 2 to 5- Pomegranate peel treated with each of the four tannin-degrading bacteria. The five treatments of the second experiment included 1- Diets containing pomegranate peel without treatment (control treatment), 2-5- Diets containing pomegranate peel treated with each of the four tannin-degrading bacteria.

Results and discussion:

 Applying tannin-degrading bacteria reduced the tannin in pomegranate peel (P<0.05), which is caused by the tannin-degrading bacteria. In an experiment of ensiling and adding polyethylene glycol and urea to pistachio hull for tannin removal, total tannin decreased. The concentration of total tannin with the potential and rate of gas production, truly decomposed organic matter, microbial biomass production, and microbial biomass production efficiency improved in pomegranate peel treated with tannin-degrading bacteria compared to the control (P<0.05). Perhaps the reason for the decrease in gas production potential in the control treatments compared to the treatments treated with bacteria is their higher amount of tannins, because tannins and phenolic substances by forming bonds and complexes with nutrients such as carbohydrates, proteins, reduce the availability of microorganisms. Ruminants to them and as a result reduce their decomposition. Similar to the results of the present experiment, other studies have also shown the positive effect of tannin removal on the improvement of gas production parameters. NH3 concentration and population of protozoa of pomegranate peel treated alone and in the diet increased compared to the control (P<0.05). The reason for the increase in NH3 concentration and protozoa population after degrading the tannins with bacteria can be the presence of tannins and polyphenolic compounds in this edible material. By binding to protein and reducing the rate of protein decomposition, tannins reduce the concentration of NH3, on the other hand, these structures lead to the rupture of the protozoa cell membrane, the inactivation of enzymes, and the reduction of the substrate needed for cell metabolism. The percentage of digestibility of dry matter, NDF, and ADF of pomegranate peel processed alone and in the diet with tannin-degrading bacteria increased compared to the control (P<0.05). Due to the reduction of the tannin level by the isolates, the activity of proteolytic enzymes has probably increased, and releasing nutrients from the binding of tannin, has improved the digestibility of the materials. An increase in cell wall digestibility has been reported as a result of treatment with tannin-degrading bacteria in laboratory conditions. Gas production potential and rate, separation coefficient, microbial viable mass production, and microbial viable mass production efficiency were improved in diets containing processed pomegranate peel compared to the control (P<0.05).

Conclusion:

 The use of tannin-degrading bacteria in the processing of pomegranate peel by reducing the tannins concentration led to an increase in the digestion and fermentation potential of pomegranate peel and diets containing pomegranate peel processed with tannins-degrading bacteria compared to the control. Therefore, considering the positive effects of processing pomegranate peel with tannins-degrading bacteria, it can be said that processing it by reducing tannins is a suitable solution to improve its nutritional value.

 Raising healthy calves is indeed a critical concern in the dairy industry. Close up diets have important effects on the quantity and quality of produced colostrum, on the other hand, colostrum and milk are considered the most important sources of food that contain energy, protein, and other nutrients for the newborn calf’s growth. Including fatty acids in the late pregnancy supplements are controversial because of the potential reduction of cows DMI. Also, the growth and health of calves can be influenced by feeding linoleic acid to pregnant cows. Safflower as a rich source of linoleic acid (55-70%) is a significant oil alternative product, and has a high nutritional value. This study aimed to examine the effects of safflower seeds and palmitic fatty acids on the transition diet in cow feed consumption, colostrum quality, blood parameters, body measurements and Holstein calf performance.

Materials and methods :

Thirty pregnant Holstein cows, 15 primiparous and 15 multiparous, were used 21 days prior to the expected calving date. The experiment was conducted using a completely randomized experimental design with three treatments and ten replicates in every treatment. Cows were randomly assigned to experimental treatments so that each treatment have an average body weight 659.34 ± 84.2 kg, parity 2.04 ± 1.31 and body condition score (BCS) 3.23 ± 0.15 The experimental rations have similar energy and protein content. Diets were thoroughly mixed and fed to cows based on the recommendations of the US National Research Council (NRC, 2001). The experimental rations included: 1) Control diet without fat source (Ctrl), 2) Diet with palmitic fatty acid (SFA), and 3) Diet with safflower seed (UFA). Daily feed intake was calculated by subtracting distributed feed to every cow from the leftover amount on following day. Newborn calves were weighed immediately after birth. An individual colostrum yield for every cow was recorded at each milking. The quality of colostrum was determined using an optical refractometer (ATC., China). The body weight and skeletal parameters of calves were evaluated at birth day, 21 d, and 49 d. Blood samples were taken immediately after birth, two hours after colostrum feeding and on days 3, 7, 21, and 49 via the jugular vein. Samples were centrifuged at 3000× g and the plasma was stored at −20°C until analysis. Plasma metabolites were analyzed using an autoanalyzer (Alcyon 300., USA). Colostrum composition (fat, protein, lactose, solids, solids not fat) was determined using a Milkoscan (Foss Electric, Hillerød, Denmark). Fatty acids profile were measured according to O'Fallon (2007) et al., using gas chromatography (GC) equipped FID detector and 100 meter column. Data were analyzed using the MIXED procedure of SAS using a completely randomized design with ten replications.

  Results and Discussion:

 Using sources of SFA (palm oil powder) and UFA (safflower seeds) in the transition diets were not affected on dry matter intake in Holstein dairy cows (P>0.05). Dry matter intake in Ctrl, SFA, and UFA were 10.29, 10.98, and 10.80 kg per day, respectively. We found that  using SFA and UFA did not have any significant effect on colostrum parameters such as colostrum volume, the percentage of fat, protein, lactose, total solids, fat not solids, and also, immunoglobulin concentration, and Brix number of colostrum (P>0.05). The colostrum volume in UFA and SFA treatments was higher than in the Ctrl treatment, but this difference was not significant (5.82, 5.23, and 4.19 kg, respectively). According to the results, the researchers stated that adding raw and processed safflower seeds to the diet did not have any significant effect on milk production, milk fat, protein, and lactose in Holstein dairy cows (Paya and Taghizadeh, 2020). Feeding omega-6 sources in the transition period (35 days before calving) caused higher colostrum protein and Brix values (Salehi et al., 2016) but was not consistent with our results. Feeding palm fat powder as a source of SFA and safflower seeds as UFA did not have any significant differences in concentration of short chain, medium chain, and long chain fatty acids in colostrum. It was reported that various fat sources in the rations of dairy and transition cows did not affect colostrum fatty acid and milk fatty acid. However some studies showed that different fat sources in the diet of dairy cows changed the fatty acid profile in milk. In general, it can be stated that because of the high-producing dairy cows experience a negative energy around calving, the diet energy meets the requirements, which probably causes the fatty acid composition of the colostrum not to be affected. Our results showed that blood factors such as glucose, cholesterol, triglycerides, blood urea nitrogen, ALT, AST, total antioxidant capacity, malondialdehyde, total protein, albumin, calcium, magnesium, phosphorus, and HDL did not differ between treatments. It was observed that the addition of SFA and UFA had no significant effect on the birth weight of calves, weight at d 21 and 49, and dry matter intake during the experimental period. Skeletal parameters such as hip height and width, withers height, chest circumference, and body length at 3, 21, and 49 days had no significant differences in the treatments.

  Conclusion:

 It seems that using saturated and unsaturated fatty acids sources in the transition diets did not reduce feed intake. Moreover, it had no significant influence on the calves' performance, bone condition, the colostrum's quality and the colostrum fatty acids profile.

Lack of animal feed, especially with development of industrial methods of animal husbandry waste in many parts of the world, has led farmers and researchers to try identifying and using agricultural and livestock waste and new food sources for animal nutrition, including poultry manure and urea is mentioned in the diet of ruminants. Due to the fact that no research has been done on the effect of barley grain processing methods and non-protein nitrogen sources in the diet on rumen degradability, gas production and microbial protein synthesis in sheep, the present study was conducted.

This experiment was conducted in a completely randomized design with seven treatments including a control treatment containing whole barley grain (without milling) and without urea and chicken manure, treatments 2, 3 and 4 containing processing method of milling, filling and pelleting with a certain level of urea, respectively. (1%) And treatments 5, 6 and 7 containing processing methods of milling, filling and pelleting with a certain level of poultry manure (12%) were performed on sheep. Each treatment consisted of 5 fattening lambs at the age of 3 months 24±1 which were kept individually in separate cages for 14 days of acclimatization period and 84 days of fattening period. In the second experiment, rumen degradability of dry matter, crude protein and NDF of experimental diets were measured using a nylon bag method with 3 fistulated male sheep that were fed in the maintenance level. Extent and rate of gas production were done based on Menk and Stingas. The NH3-N concentration was determined following the Broderick and Kang (1980) technique. Purine derivatives and was measured by the method of Chen and Gomes (1995). Rumen fluid was collected for 5 consecutive days in the end of each period and ruminal fermentation parameters containing pH and NH3-N and were determined. Urine of sheep was collected end of each period for 5 days and microbial protein synthesis was estimated by measuring purine base. Data were analyzed using SAS software version 9.9 (54) using GLM procedure.

The apparent digestibility of dry matter and organic matter were significantly different, and the control treatment (whole barley grain without urea and poultry manure) had the highest apparent digestibility. Digestibility in non-fibrous carbohydrates was significantly different, so that treatment 5 (processing method of milling with poultry manure) had the highest apparent digestibility. Different parameters of degradability of dry matter, crude protein and insoluble fibers in neutral detergent of experimental treatments indicated significant differences between treatments (P<0.05). Barley grain processing with non-protein nitrogen sources caused a significant difference in the fast decomposing part, slow decomposing part and degradable part of dry matter, crude protein and insoluble fibers in the crude protein neutral detergent of experimental treatments. Effective degradability of dry matter, crude protein and insoluble fibers in neutral detergent at 2, 4 and 6% per hour passage rates had a significant difference between experimental treatments. The results showed that there was a significant difference between the experimental treatments in terms of gas production parameters and the amount of gas produced in 96 hours (P<0.05). There was a significant difference between experimental treatments in terms of digestibility of organic matter, amount of metabolizable energy and concentration of short-chain volatile fatty acids. The highest pH was assigned to treatment 7 (6.30) and the lowest pH was assigned to treatment 1 (6.10). Ammonia nitrogen had a significant difference in experimental treatments. The highest ammonia nitrogen was related to treatment 5 (11.45 mg/dL) and the lowest ammonia nitrogen was related to treatment 3 (10.38 mg/dL). The excretion rate of each of the purine derivatives (allantoin, uric acid, xanthine + hypoxanthine) and the total urinary excretion of purine derivatives and the amount of microbial protein synthesized in the rumen were affected by the test diets and the observed difference was significant (P<0.05). There was a significant difference in rumen pH in experimental treatments. The results showed that barley grain processing methods with non-protein nitrogen sources had a significant effect on rumen degradability, gas production, rumen parameters and microbial protein synthesis compared to the control group.

In general, the use of urea (1%) and poultry manure (12%) with different methods of barley grain processing without negative effects on rumen degradability, rumen liquid parameters and gas production in terms of microbial protein synthesis can be useful.

In the broiler breeding industry, chickens are often reared in confinement at high stocking densities, which can make them susceptible to infectious diseases. Antibiotics, growth promoters, and anti-coccidial drugs are frequently used as feed additives to elevate growth rates, combat diseases, and lower losses. However frequent use of antibiotics in broiler diets may result in a rise in the antimicrobial resistance of both human and animal bacteria. Alternatives to antibiotics as growth promoters for broilers could decrease bacterial resistance to antibiotics, while at the same time maintaining growth and improving carcass composition. In addition, the bioactive components of herbal plants have a high free radical inhibitory activity that may help the endogenous oxidative status of animals and thus may prevent oxidation in meat and lead to improved meat quality. The objective of this study was to investigate the effect of thyme (Thymus vulgaris) on growth performance, blood metabolites, and meat quality of broilers at high stocking density‏.

This experiment was conducted based on a completely randomized design with a 2×2 factorial arrangements. A total of 216 1-d-old male broilers (Ross 308) were allotted to one of four treatments with four replicates. Two different stocking densities (low stocking density (LSD): 9 birds/m2 and high stocking density (HSD): 18 birds/m2) were tested with two different thyme levels: zero and 0.1%. Chickens had given ad-libitum access to water drinking and diet. At the end of the experiment (42 days old), two birds with the closest weights to the mean weight of the pen were selected, and after blood sampling slaughtered for determining meat quality. Body weight gain (BWG) and feed intake (FI) of birds were measured per pen at the end of each period. Mortality and the weight of birds that died or were culled during the experiment were recorded. Corrected feed conversion ratio was calculated based on mortality for these periods. Blood biochemical indices (glucose, cholesterol and triglyceride) were determined using a clinical biochemistry autoanalyzer using a kit from Pars Azmoun, Tehran, Iran. To determine the Water-holding capacity, 5 gr of breast sample were placed in filter paper and centrifuged at 1500×g for 4 min. Then the samples were placed in an oven at 70 °C for 24 h. Finally, the Water-holding capacity was calculated from the difference in the weight after centrifugation and the weight after drying, divided by the initial weight multiplied by 100. Collected data were subjected to ANOVA using the GLM procedure of SAS (SAS, 2005). Analysis of variance was performed using a completely randomized design with a factorial arrangement of treatments. Tukey’s multiple range test was used to determine differences among the treatment means. Statistical significance was considered at P<0.05.

The results showed that in the starter period, birds in the HSD group had the highest feed intake and weight gain compared to the LSD group (P<0.05). HSD caused a significant decrease in feed intake and body weight and a significant increase in feed conversion ratio in grower, finisher, and the total periods compared to LSD (P<0.05). A significant increase in glucose, heterophil concentration, and heterophil to lymphocyte ratio and a significant decrease in glutathione peroxidase and lymphocyte concentrations were observed in birds raised in HSD than LSD (P<0.05). Also, HSD decreased water holding capacity and increased cooking loss and dripping loss of breast meat (P<0.05). The addition of thyme powder increased feed intake and body weight and decreased feed conversion ratio in grower, finisher, and the total periods (P<0.05). The treatment containing thyme decreased the concentration of glucose, heterophil, and heterophil to lymphocyte ratio and increased the concentration of glutathione peroxidase, white blood cells, and lymphocytes (P<0.05). A significant increase in water holding capacity and a significant decrease in cooking loss, dripping loss, and thiobarbituric acid of breast meat were observed in the treatment containing thyme (P<0.05). The positive effects of thyme on reducing the negative effects of high stocking density and improving growth performance, antioxidant status, blood immunity, and meat quality of broilers could be due to its antioxidant and antibacterial properties. The improvement in the growth performance of broiler chickens caused by thyme could be partly attributed to its positive effect on nutrient digestibility. Furthermore, this positive result could be, at least in part, due to the antioxidant and antibacterial effects of herbal products in the gut.

Therefore, adding 1% thyme powder can reduce the negative effects of high stocking density on growth performance, and blood metabolites, and improve the meat quality of broilers raised under high stocking density.

Early post-hatch feed and water deprivation, as happens practically, may negatively influence the growth performance and health of broiler chickens due to severe dehydration, suppressed mitotic activity of satellite cells, poorer gut health, and development as well as retarded yolk sac (YS) absorption. Decelerated YS absorption may be associated with a higher incidence of YS infection and lower transfer of maternal antibodies from the YS to the chick body. Royal Chick is a nutritious gel providing adequate quantities of water and essential nutrients for newly-hatched chicks. The product also contains probiotic organisms, prebiotic, yeast nucleotides, and natural anti-stress substances. Royal Chick is an innovative nutrient-enriched powder product that forms a jelly mass when mixed with water. As claimed by the manufacturer, the product prevents initial weight loss, alleviates oxidative stress, improves skeletal muscle growth, and stimulates the development of the digestive and immune systems of the newly hatched chicks. This study aimed to evaluate the effect of early feeding with Royal Chick on productive performance, carcass traits, immune system function, and jejunum morphometry of broiler chickens. A total of 420 d-old straight-run Ross 308 broiler chicks were used in a completely randomized design with 5 treatment groups and 6 replicates per each. A group of chicks were deprived of both feed and water for the first 24 h post-hatch and served as control (CON). In the second group, each bird was treated with HRCH gel in two separate 2 g dosages from which the first was given in the chick box and the second was administered immediately after placement in combination with the first meal of the starter diet (T1). In the third group, each bird was treated with a mixture of 2 g HRCH and 2 g starter feed in the chick box (T2). In the fourth group, each bird was treated with a single 2 g dose of HRCH in the chick box (T3). In the fifth group, each bird received a mixture of 2 g HRCH gel and 2 g starter feed immediately after placement (T4). All chicks were held in chick box up to 24 h post-hatch and then were transferred to the associated floor pens and reared for 42 days on standard starter (2 to 10 d of age), grower (11 to 24 d of age), and finisher (25 to 35 d of age) diets. On days 10, 24, and 35 birds of each pen were weighed together. Offered feed and refused feed were also weighed and mortality records were kept for each phase. Then weight gain (WG), feed intake (FI), and mortality-corrected feed conversion ratio (FCR) were calculated. On days 2 and 25, blood samples were taken from 2 birds per replicate to evaluate maternal immunity and humoral immune responses to vaccination against Newcastle disease virus (NDV), infectious bronchitis virus (IBV), and avian influenza virus (AI). The birds from which blood samples were taken on day 2 were killed at the same time to measure residual yolk sac weight. At the end of the experiment, 2 female birds per pen were weighed and decapitated to investigate carcass traits and to sample the mid jejunum for morphometric analysis. Birds in T1 and T2 groups tended to have lighter residual yolk sac than their control counterparts (P=0.076). During the starter phase, T2, T3, and T4 groups had significantly (P<0.05) higher WG and FI compared to those in the control group with no improvement in FCR. During the grower phase, the T4 group consumed more feed than the control one (P<0.05). No treatment effect was detected on performance traits at the finisher phase and throughout the experimental period (P>0.05). Birds in T2 and T3 groups produced the most pronounced antibody responses against IBV. The highest carcass yield was obtained in birds treated with a combination of HRCH and starter feed in the chick box (T2). The same birds also tended to have the highest breast yield (P=0.077). Administration of hydrated Royal Chick gel in chick box (with or without a starter diet) or immediately after placement (in combination with a starter diet) can bring beneficial effects on the health and productivity of broiler chickens. Further investigations are necessary to identify possible interactions of different EF regimens involving HNG with breeder age, deprivation duration, and pre-placement environmental conditions on subsequent performance and health status in broiler chickens.

In the poultry industry, feed efficiency is of great importance in order to reduce the cost of feed by maximizing production efficiency. To achieve this result, the use of synthetic amino acids, such as the amino acids methionine, lysine, arginine, etc. in poultry nutrition can play an effective role in animal performance. Application of monosodium glutamate in animals cause to increased levels of triglycerides, total protein, cholesterol and blood glucose in rats. Addition of 1% monosodium glutamate in broiler diets increased feed intake compared to the control group and also in relation to weight gain at the level of 0.25 and 0.5% monosodium glutamate had a significant decrease compared to the control group. Therefore, considering the role and importance of laying hen performance during the production process and due to the very important role of monosodium glutamate in the occurrence of these changes, the effects of consumption of different levels of monosodium glutamate on performance, egg quality characteristics and blood parameters were investigated.

In this study, 60 laying hens of "Hy-Line W36" strain at the age of 68 to 74 weeks in 4 treatments and 5 replications and 3 hens per replication were used. The experiment was conducted as a completely randomized design in four periods 14-day for 8 weeks. Experimental treatments included 0, 0.4, 0.8 and 1.2% levels of monosodium glutamate per kg of feed. To better benefit from the data, all measurement factors except body weight gain were sampled and evaluated at the end of every two weeks. Egg mass was also obtained by multiplying the percentage of daily egg production by the average weight of eggs produced on the same day. Egg quality traits including height and diameter of albumin and yolk, relative weight of yolk and shell and albumin, shell thickness, shape and specific gravity were measured. Blood parameters were selected from two cages in each cage every two weeks and blood samples were taken from their wing veins and the concentrations of glucose, cholesterol, triglyceride, HDL and VLDL were measured using a Pars azmon kit and a spectrophotometer. Experimental data were statistically analyzed using statistical software (2002) SAS 9.1. Significant differences between treatments were compared with Duncan's multiple range test at a significance level (P<0.05).

The effect of adding treatments on the traits related to egg mass production and feed conversion ratio at the age of 72-74 weeks and feed consumption in all weeks of the experiment was significant. Today, several neurotransmitters have been identified to regulate feed intake, one of which is glutamate, which is most abundant in the central nervous system, which reduces feed intake in broilers. Feed intake is reduced by adding monosodium glutamate throughout the production period. Moreover of experimental treatments on Haugh unit, albumin and yolk height in the whole period was significant so that adding 0.4% of monosodium glutamate to the diet was able to increase the height of albumin and Haugh units and decrease yolk height compared to other treatments. Adding 0.8% monosodium glutamate increased the white diameter in the whole period compared to the control treatment and the treatment containing 0.4% monosodium glutamate. The data showed that adding 0.8% of monosodium glutamate to the diet could increase cholesterol, triglyceride and VLDL concentrations at 70-72 weeks of age compared to other treatments. Also, adding 1.2% of monosodium glutamate to the diet has been able to increase the concentration of HDL and VLDL at the age of 76-74 weeks.

In general, it can be concluded that the addition of monosodium glutamate to the diet has no significant effect on the percentage of production, the relative weight of yolk, albumin and egg weight despite the significant effect on blood parameters that was observed also it did not have qualitative parameters of the shell. On the other hand, the addition of 0.4% monosodium glutamate to the diet reduced feed consumption in the entire production period. Also, this treatment was able to increase the height of the albumin and Haugh unit and decrease the height of the yolk compared to other treatments in the entire production period.

The egg production curve is defined graphically as the relationship between the number of eggs and laying time, which indicates the biological efficiency of a hen and can be effective in the selection and nutritional management of laying hens. Egg production is an essential section of the poultry industry. Appropriate mathematical models accurately represent the production phases of the hen and provide a valuable tool for biological comparisons and interpretations. Also, egg production curves help predict egg production, determine the appropriate age for poultry culling, and economic decisions. Sigmoid growth models are often used to describe size over time in plants, animals, and humans. In laying hens, the shape of the cumulative egg production curve is similar to the growth curve. Therefore, different growth models may be used to model the cumulative egg production curve. Khazak hen is one of the native birds of the Sistan region (Iran), and natural selection has adapted this bird to the conditions of Sistan over the years. The body of this chicken is small, and has low growth and is mainly kept for egg production. Since laying patterns is different in populations. Thus, the use of an appropriate model to describe the specific laying pattern of each population is necessary. Therefore, this study was conducted to investigate growth models to describe the cumulative egg production and weight of eggs and select the best model for the Khazak hen. The present study was conducted in the Research Center of Domestic Animals (RCDA), the Research institute of Zabol, Zabol (Iran). Khazak pullets are identified using foot-banded numbers before they start laying. During the experiment, all birds had access to water and feed ad libitum. The egg production was recorded daily for each hen separately. Based on daily records, the weekly egg production of each bird was calculated and then used the calculation of the cumulative egg production. A total of 365 pellet egg production records were used to analyze the production curve from the first to the fortieth week of laying. Five growth models (Gompertz, Logistics, Richards, Lopez, and Weibull) were fitted on cumulative egg production and weight records. The goodness of fit criteria, including Akaike information criterion (AIC), mean square error (MSE), Bayesian information criterion (BIC), and adjusted coefficient of determination ( ), were used to compare the growth models and to select the best model. All models were fitted on egg production records using the nlme package in R software, and the parameters of each model were estimated. After fitting the models, the cumulative production values for different ages were predicted by the models and were compared with the actual values over 40 weeks. Based on the goodness of fit criteria, the Lopez mod had the highest  value and lowest values of AIC, BIC, and MSE for cumulative egg production. While the Weibull model was the best model than other models to describe cumulative egg weight in terms of the goodness of fit criteria. The Gompertz and Logistic models overestimated initial production and underestimated the final production compared with other models. Estimates of time and production at the inflection points using Lopez and Weibull models were close to actual values of cumulative egg production and weight, respectively. Also, prediction of cumulative egg production and egg weight in different weeks using Lopez and Weibull models was accurately, respectively. In literature, various models were reported as the best model to describe the egg production curve, which indicates that the appropriate model specific to each breed should be used to evaluate its curve. The overestimation and underestimation of initial and final production using Logistic models were reported in other research that was similar to our findings. The important application of egg production models in poultry is to estimate the economic and genetic value by predicting total egg production from some records, which can be a suitable tool for biological comparisons and interpretations. The results of the present study, showed that the Lopez and Weibull models were the best models to describe the cumulative egg production and egg weight based on four good fit criteria, respectively. Therefore, these models can be used to describe the cumulative egg production and egg weight in Khazak hens. The application of these growth models can be useful to nutritional management and breeding programs to improve and change cumulative egg production and egg weight.

In the past, vitamins were considered as unknown growth factors, but during the twentieth century, their structure and nature were gradually discovered. These compounds are necessary to maintain the integrity of the tissues and general health of the body. Broiler chickens are unable to synthesize vitamins (except vitamin C) or have the ability to make limited amounts of them (group B and K2). For this reason, vitamins should be added to broiler feed as a supplement. Vitamins interact with other nutrients in various ways. The main reference for vitamin requirements in broilers is the National Research Council (NRC, 1994). The recommended amounts ensure conditions where there are no severe deficiencies. Applying the NRC recommendations cannot guarantee the genetic potential of today's birds. Because these values were taken from old studies and using pure feeds in laboratory conditions. Due to the dependence of Iran's poultry industry on the import of vitamins, unfortunately, in recent years, few studies have been conducted in the country on the appropriate pattern of adding vitamins to the diet of broiler chickens. Therefore, it is necessary to examine the lower levels than the recommendation of the Ross 308 strain catalog (Aviagen, 2019) as the dominant strain of the country and to propose an optimal model for different regions that does not have a negative effect on the performance and safety traits and to reduce the need to import this strain. It will also follow the products.

The aim of this study was to determine the optimal pattern of vitamin supplementation in diets based on corn, wheat waste and soybean meal on production traits, carcass characteristics and immune responses of broilers from 1 to 42 days of age in Fars province. A total of 500 Ross 308 broilers with similar mean weight (mixed sex) were distributed in a completely randomized design with five treatments, five replications and 20 chickens per replication. Experimental treatments included five levels of vitamin supplementation: 1) control (100% of the recommended values of Ross 308, 2019 strain catalog), 2) 90% of the recommended values of Ross 308, 2019 strain catalog, 3) 80% of the recommended values of Ross 308, 2019 strain catalog, 4) 70% of the recommended values of Ross 308, 2019 strain catalog and 5) 60% of the recommended values of Ross 308, 2019 strain catalog. At the end of each period, the feed consumption and body weight of the birds were recorded with a digital scale with an accuracy of ±0.01. At the age of 39 days, blood was drawn from the vein under the wing of two birds from each experimental unit, with a syringe containing EDTA anticoagulant, and the blood sample was quickly transferred to the laboratory in a flask containing ice for differential counting of white blood cells. At the end of the 42nd day of rearing, two birds from each experimental unit were slaughtered to measure the relative weight percentage of carcass components. To measure the humoral immune response, the injection of 0.5 ml sheep antigen (SRBC) at the age of 21 days was used. CBH skin hypersensitivity test was also used to measure cellular immune response.

The highest and lowest mean body weight gain and feed intake belonged to the vitamin pattern of 100 and 60% of the recommendation of Ross 308 strain, respectively (P<0.01). The best feed conversion ratio and production index belonged to the vitamin pattern up to 90% of the Ross strain recommendation (P<0.01). The highest and lowest percentages of pectoralis muscle (22.2% and 19.2%) were related to the pattern of 100 and 60% of vitamin supplementation recommended by the Ross strain (P<0.01). The effect of reducing vitamin supplementation on cutaneous basophil hypersensitivity (CBH), serum antibody level against SRBC and percentage of heterophils, lymphocytes and heterophil to lymphocyte ratio was not significant.

There was no significant difference between the functional indices and most importantly the production index of treatment 1 (100% vitamin pattern) and treatment 2 (90% vitamin pattern). Carcass traits and indicators related to humoral and cellular immune systems did not show significant differences too. As a result, a 10% reduction in the level of vitamin supplementation compared to the recommended level of the Ross 308 catalog is possible and suggested for raising broiler chickens. The final result is that in the breeding conditions of Fars province poultry farms, it is possible to reduce the level of vitamin supplements in diets containing wheat waste up to 90% of the recommendation of Ross 308 strain compared to the control diet.

 The Ferula badrakema from the Apiaceae family is a resinous plant with a strong smell that is native to Iran (Rechinger et al., 1994). The anti-bacterial and anti-fungal properties of Ferula badrakema are believed to be due to its high content of alpha-pinene and beta-pinene. Similar to other Ferula species, this plant is a rich source of sesquiterpene coumarins (Bukreeva and Pimenov, 1991). To the best of our knowledge, no study has been done on the volatile compounds of this species. However, studies on other species of this plant that grow in other parts of the world have been reported (Başer et al., 2000; Takeoka, 2001, Iranshahi et al., 2006). Saccharin is a sulfonamide produced from compounds found in coal tar (Abdelaziz et al., 2011). Its taste is 300 to 500 times sweeter than sucrose. Due to its high sweetness, it is widely used to improve feed palatability and can increase feed intake (Feighner et al., 1987). Studies by Han et al. (2019) have shown that Japanese quails prefer sucrose solution instead of ordinary water due to its palatability. However, few studies have been conducted on the physiological relationship between sweeteners and the gastrointestinal tract of broilers (Kimmich et al., 1989). Considering that most medicinal plants have a bitter taste and reduce the feed consumption and growth of chickens, this experiment aimed to investigate the effects of adding sweeteners and preventing the activation of bitter taste receptors of the Ferula plant on the growth performance, immune system and blood metabolites of chickens. This experiment was conducted using 468 one-day-old commercial broilers from the Ross 308 strain with 6 treatments, 6 replicates and 13 birds each in a completely randomized design as a 3×2 factorial arrangement (3 levels of Ferula badrakema root powder at the levels of 0, 0.75 and 1.5% and two levels of 0 and 0.15% sodium saccharin in diet). Standard diets during the periods of starter (1-10 d), grower (11-24 d) and finisher (25-42 d) were used. The diets were formulated using the UFFDA software to provide all the requirements of the broilers based on the recommendations of the Ross 308 strain (2019). Throughout the experiment, the birds had ad libitum access to water and feed and an hour darkness and 23 hours of light was provided. The initial temperature of the room was 32°C, which was reduced by 0.5°C per day according to the Ross company guidelines, until it reached 21°C at the age of 21 days and remained constant after that. Average feed intake, weight gain and feed conversion ratio for each group were measured at the end of each period. To measure blood parameters, one male bird at the end of the experiment (42 d), was selected from each replicate and blood samples were taken from the wing vein in syringes without anticoagulant, and after centrifugation, the sera were collected in 0.5 ml microtubes and kept at -20°C until the further analysis. To evaluate the humoral immune response, 0.1 ml sheep red blood cells (SRBC) suspension was injected to breast muscle of one bird from each replicate on 28 and 35 d and total antibody, IgG and IgM were measured.  Adding saccharin to the diet caused a significant increase in feed intake during the periods of 1-10 and 1-42 days (P < 0.05). The interaction effect of saccharin and Ferula on feed intake was significant (P < 0.05) during the periods of 25-42 and 1-42 days; so the addition of Ferula to diets containing saccharin increased feed intake while in diets without saccharin, it reduced feed intake. The body weight gain of chicks at the age of 1-10, 42-25 and 1-42 days in the treatment with 0.15% saccharin was significantly (P < 0.05) higher than the treatment without saccharin; but adding Ferula had no significant effect on the weight gain. Addition of Ferula and saccharin to the diet and their interaction had no significant effect on the carcass traits of broilers. Adding saccharin to the diet caused a significant increase (P < 0.05) in blood uric acid, but it did not have a significant effect on the concentration of other blood metabolites. An independent comparison of Ferula supplemented diets with treatment without it, showed that Ferula caused a significant (P < 0.05) increase in blood uric acid, albumin and phosphorus and a significant decrease in blood cholesterol and triglyceride. The titer of total antibody and IgG at the age of 35 days, as well as IgG and IgM at the age of 42 days, increased compared to its 0 level under the influence of Ferula consumption. In general, the results showed that the use of sodium saccharin in the diet prevents the reduction of feed intake caused by the bitter taste of Ferula, and the consumption of Ferula improves the immune system and reduces the concentration of cholesterol and triglycerides in the blood broiler chicks.

The quality and quantity of dietary protein are primary factor influencing growth and feed costs. Seeds of faba bean (Vicia faba L), similarly as soybean meal, belong to high-protein feeds. The use of faba beans in poultry feed is limited despite having a suitable chemical composition, the main reason of which is the presence of anti-nutritional factors in this seed. Golestan Agricultural and Natural Resources Research and Education Center has produced a zero-tannin faba bean seeds variety (Mahta cultivar) that does not have the nutritional limiting factors of normal beans. The aim of this study was to investigate the effect of different levels of zero-tannin faba bean seeds (Mahta cultivar) on growth performance, some immune and biochemical parameters of blood, morphology and microbial population of small intestine and meat quality of broiler chickens.

320 of one-day-old Ross 308 broilers with 4 treatments were used in a completely randomized design with 4 replications and 20 equal mixed birds of each sex in each replication for 42 days. Experimental treatments included 1- control diet (without faba beans and based on corn-soybean meal) 2- diets containing 10% zero-tannin faba bean 3- diets containing 20% zero-tannin faba bean and 4- diets containing 30% zero-tannin faba bean. Then, the growth performance of chickens, blood biochemical (triglyceride, cholesterol, LDL, VLDL and HDL concentrations) and immune (heterophil and lymphocyte percentage) indicators, intestinal jejunum morphological (villi length, villi width, crypt depth and thichness of muscle layer) and ileum contents microbial population (lactobacillus and escherichia coli) parameters and meat quality (pH, malondialdehyde, peroxide number and free fatty acids) of broiler chickens were measured and recorded. Finally, the analysis of data was performed using GLM method by SAS software. The means were compared using Tukey's multiple range tests.

The results showed growth performance (feed intake, weight gain and feed conversion ratio) of the whole period (1 to 42 days) of birds fed with different levels of diets containing zero-tannin faba bean (0, 10, 20 and 30%) was not significant. There was also no difference between the growth performance of birds fed diets containing zero-tannin faba bean compared to birds receiving the control diet (without beans). A decreasing linear change in the weight gain of the whole period was observed with the increase in the percentage of zero-tannin faba bean (P<0.05). So, the birds that were fed with the control diet (without beans) and 10% zero-tannin faba bean had a better weight gain compared to other treatments, equal to 1738 and 1748 grams respectively, followed by the birds receiving the diet containing 20% zero-tannin faba bean had weight equal to 1623 grams and finally, the birds fed with a diet containing 30% zero-tannin faba bean had weight equal to 1574 grams (P<0.05). Some blood biochemical and immune parameters of broilers were not affected by different levels of zero-tannin faba bean in the diet. However, the amount of changes in HDL, the ratio of HDL to cholesterol, serum LDL and the percentage of heterophil, lymphocyte and the ratio of heterophil to lymphocyte in the blood of broiler chickens fed with a diet containing 20% of zero-tannin faba bean is worthy of consideration and requires further investigation and study (P>0.10). Also, morphological parameters of intestinal jejunum were not affected by different levels of zero-tannin faba bean in the diet. However, citizenship analysis showed linear changes in villi length, villi width and crypt depth of broiler intestines. The tendency to increase villi length was observed in birds fed diets containing 10% zero-tannin faba bean compared to other diets (P= 0.08). Villi width (P<0.05) and crypt depth (P=0.05) were lower in birds fed diets containing zero-tannin faba bean compared to the control treatment (without faba beans). Microbial population of escherichia coli and lactobacillus ileum contents were not affected by different levels of zero-tannin faba bean in the diet. The use of different levels of zero-tannin faba bean improved meat quality by decreasing pH, malondialdehyde concentration, peroxide and free fatty acids in broiler thighs (P<0.05).

Finally, according to the present results, it seems that among the different levels of zero-tannin faba bean (10, 20 and 30%) in the diet of broiler chickens, the level of 10% zero-tannin faba bean in terms of broiler performance should be more appropriate and competitive with the control diet (without faba beans and based on corn-soybean meal).

Paratuberculosis, or Johne’s disease, is a chronic, granulomatous, gastrointestinal tract disease of goat and other ruminants caused by the bacterium Mycobacterium avium ssp. paratuberculosis (MAP). The clinical signs of disease in goat are pipestream diarrhea, weight loss, and edema due to hypoproteinemia caused by protein-losing enteropathy. Knowledge concerning genetics of susceptibility to MAP infection can contribute to disease control programs by facilitating genetic selection for a less susceptible population to reduce incidence of infection in the future. The opportunity for genetic improvement in susceptibility to infection is evidenced by estimates of heritability of MAP infection ranging from 0.03 to 0.28 (Kirkpatrick and Lett, 2018). Domestication and selection has significantly changed the behavioral and phenotypic traits in modern domestic animals. The selection of animals by humans left detectable signatures on the genome of modern goat. The identification of these signals can help us to improve the genetic characteristics of economically important traits in goat. Over the last decade, interest in detection of genes or genomic regions that are targeted by selection has been growing. Identifying signatures of selection can provide valuable insights about the genes or genomic regions that are or have been under selection pressure, which in turn leads to a better understanding of genotype-phenotype relationships. The aim of this study was to identify the selection signatures using the unbiased Theta method associated with resistance to Johne’s disease in two Italian goat breeds. The work described here is a case–control association study using the Illumina Caprine SNP50 BeadChip to unravel the genes involved in susceptibility of goats to Johne’s disease. Goats in herds with a high occurrence of Johne's disease were classified as healthy or infected based on the level of serum antibodies against MAP, and 331 animals were selected for the study. For the Siriana breed 174 samples (87 cases and 87 controls) were selected from 14 herds and for the Jonica breed 157 samples (77 cases and 80 controls) were selected from 10 herds. Cases were defined as animals serologically positive for MAP by ELISA with a sample to positive ratio (S/P) higher than 0.7 and MAP negative animals had a S/P lower than 0.6. Positive animals were tested twice with the ID Screen Paratuberculosis confirmation test. The 331 samples were genotyped using the Illumina GoatSNP50 BeadChip. SNP missing 5% of data, with MAF of <1% and Hardy–Weinberg equilibrium p-values <10−6 were removed. The genotyping efficiency for samples was also verified, and samples with more than 5% missing data were removed. Grouping was done to infer selection signatures based on FST statistic. Bioinformatics inquiries were conducted employing the Ensembl database (Cunningham et al., 2022), specifically for caprine genes (assembly ARS1). The aim was to pinpoint potential candidate genes that have either been previously reported in, or are situated within the genomic regions encompassing the peak of absolute extreme FST values. In this context, regions corresponding to the top and bottom 0.01% of acquired positive and negative FST scores were earmarked as areas undergoing selection. The identification of genes was executed through the application of a 250 Kb window both upstream and downstream of each core SNP. By applying a threshold at the 99.90 percentile of the obtained Theta (θ) values, a total of 13 distinct genomic regions were identified in the Jonica breed. These regions were situated across chromosomes 1, 5, 7 (in 2 regions), 8, 9 (in 2 regions), 11, 16, 17, 18, and 20 (in 2 regions). Similarly, in the Siriana breed, genomic regions were pinpointed on chromosomes 3, 5 (in 2 regions), 10, 12, 16, 17, 18, 23, 24, and 29. Further exploration through bioinformatics tools brought to light the overlap of these genomic regions with genes associated with the immune system, disease resistance, bacterial infection resilience, response to oxidative stress, and tumor suppression. The study population size is relatively modest, predominantly due to the intricacy of procuring a substantial volume of blood samples from goats within commercial herds that have been diagnosed with JD and are poised for culling. It's worth noting that JD diagnosis and culling procedures are not infallible preventive measures. The gradual progression of the disease often leads to late-stage diagnosis, allowing subclinical goats to intermittently excrete MAP in the environment. As the infection and disease progress, the fecal shedding of MAP increases and contributes to its horizontal transmission. In combination with genetic improvement (innate protection), vaccination (acquired protection) will support eradicating this incurable disease. To conclude, the findings of this study hold potential significance as they offer valuable insights for identifying genomic regions and subsequently, the genes that influence Johne's disease in goats. Nonetheless, additional research endeavors are essential to enhance and validate these outcomes. Utilizing a more extensive sample size, incorporating whole-genome sequencing, and implementing high-density genotyping are imperative steps to further refine and strengthen these findings.