فصلنامه پژوهشهای علوم دامی ایران
سال چهاردهم شماره 4 (زمستان 1401)

 Before weaning, dairy calves are susceptible to many pathogens and nutritional problems. For several years antibiotics have been used to overcome these problems also to obtain economic benefits in terms of improved calves performance and reduced medication costs. However, the use of antibiotics in animal husbandry is in question because of antibiotic resistance of microorganisms. In an effort to replace antibiotics from animal feeds, many additives have been proposed. Probiotic, prebiotics and Organic and inorganic mineral salts are examples of these additives. Prebiotics are non-digestible carbohydrates which are not metabolized in the small intestine and fermented in large intestine. Mannan oligosaccharides and β-glucan are prebiotics which derived from saccharomyeces cereviciae cell wall and are able to block fimbriae of patho genic bacteria, and thus prevent their adhesion to the mucous epithelium. The administration of prebiotic to calves can decrease coliform population of large intestine and colon of calves. More recently, prebiotics have been shown to have immune-enhancing characteristics Also, Copper is a microelement that is present in many important processes in the body and plays a vital role. Copper deficiency in some parts of the world is a major problem in ruminants. For this reason, dietary supplements are commonly used to regulate the diet of calf to compensate for copper deficiency. Therefore, the purpose of this study was to investigate the effects of copper nanoxide and prebiotics on blood cell count and growth performance in Holstein suckling calves.

Twenty-eight Holstein calves with an average age of 1 to 8 days and an average weight of 39±1 kg were used in a factorial experiment as a completely randomized design with 4 treatments and 7 replications. Experimental treatments include: 1) Basal diet without additives, 2) Basic diet with 4 gr of prebiotic per day, 3) Basic diet with 15 ppm nanoparticles of copper per day, 4) Basic diet + 4 gr of prebiotic + 15 ppm nanoparticles of copper per day. The diet containing feed and milk was given two times a day i.e. in the morning (8:00 am) and evening (18:00 pm). Water was offered adlibitum. Whole blood samples were collected from jugular veins on d 60, approximately 3 h after the morning feeding. Samples were sent to the laboratory under refrigeration (4°C) till analyzed for WBC count, neutrophil, lymphocyte and monocyte concentration.Results and Discussion The results showed that the copper nanoxide, prebiotics and the interaction of copper nanoxide and prebiotics could not affect the final weight of suckling calves. The results showed that feed intake, daily weight gain and feed conversion ratio of suckling calves were not significantly affected by supplementation of prebiotic and copper nanoxide in the diet during the first, second month and experimental period. Also, Body length, Wither height and Heart girth of Holstein suckling calves were not affected by copper nanoparticles and prebiotics supplementation. Prebiotic, copper nanoxide and their interaction had no significant effect on white blood cells, red blood cells, hemoglobin and hematocrit. In contrast, copper nanoxide and prebiotics significantly increased the neutrophil percentage (P <0.05).

has shown that probiotic consumption had no significant effect on functional parameters of Baluch sheep including final weight, daily gain, feed intake and dietary intake. However the result of the other study suggests that prebiotic can be supplemented to the calves for better performance. In contrary to the results of the present study, other researchers have indicated that copper nanoparticles could improve growth performance and modulate intestinal microflora and intestinalmucosal morphology in weaned piglets. In the study addition of pro- prebiotic and symbiotic to the whole milk of dairy female calves increased average daily gain but dry matter intake and blood parameters related to immune system and cell-mediated immune response were not affected. However, when a combination of probiotic and prebiotic added to the milk a better improvement in average daily gain was observed. A study reported that haematological traits (WBC count, neutrophil, monocyte, lymphocyte and hemoglobin) were unaffected by prebiotic and synbiotic in weaned pigs. However, the other study showed that immune parameters such as lymphocytes, leukocyte and neutrophils tended to increase in supplementation of symbiotic.

In general, results of this experiment indicated that using prebiotics and copper nanoxide did not improve growth performance and blood cell count except neutrophil percentage.

 To date, there is not any accurate estimation of calf mortality in the world; however, annual pre-weaning calves’ mortality was estimated to be around 7.8, 6.5, 5.5, and 2.6% in the United States, Iran, China, and Sweden, respectively. Raboisson et al. (2013) represented that most neonatal calf mortality happens at age under one month. Hill et al. (2011) reported that nutritional factors could modulate the calf immune system's functions. Studies on non-ruminants confirm that the consumption of polyunsaturated fatty acids (PUFA) relating to the n-3 FA can affect the immune response. In calves’ nutrition, using PUFA in milk or milk replacer (MR) had a pleasant effect on immune responses and antioxidant status. Supplementation n-3 FA, especially EPA and DHA, would increase the proportion of PUFA in the membrane phospholipids, which might change the performance of the immune system. The n-3 PUFA plays a critical role in influencing the immune system through various mechanisms described in detail by Calder (2012). Previous studies showed that adding n-3 PUFA to milk or MR decreases the symptoms of diarrhea and inflammatory diseases caused by viral or bacterial infections. So far, there are not enough reports regarding dietary n-3 PUFA on the APR in neonatal calves. Nevertheless, most research regarding FO supplementation and its anti-inflammatory effects on neonatal calves' health has been done on long-term consumption. As earlier mentioned, most calf mortality occurs at the first 30 days of age; consequently, long-term (more than one month) consumption of FO might not provide clear evidence to evaluate the anti-inflammatory effect of FO on the status of neonatal calves’ health. Therefore, the purpose of this study was the first evaluation of short-term supplementation of n-3 PUFA on the APR of neonatal calves.

Twenty-four bull calves, with a mean age of 34.5  3.7 days, were housed outdoors in individual pens bedded with wheat straw at the dairy farm facilities of Astan Quds Razavi Animal Husbandry and Agriculture Co. (Mashhad, Iran) in February 2019. The criteria for calf selection were, namely, the type of calf delivery (without any difficulty) and no history of disease or diarrhea. To achieve a quantitative similarity between calves, we used age and body weight as further criteria. The experiment's duration was 11 days (a week before LPS challenge and three days after LPS challenge) with an adaptation period (seven days). After the adaptation period, calves were weighed (57.5 ± 4.4 kg) and randomly assigned to 1 of 4 groups (six calves/group). Randomized calves received treatments during the study period according to the group they were already allocated: 1. negative control group (NC), 2. Positive control group (LPS challenge, PC), 3. Tallow 350 mg/kg BW group + LPS (TA), 4. Fish oil 350 mg/kg BW group + LPS (FO). All calves were fed the same diet, 5 L/d of whole milk, and had free access to freshwater during the experiment. The PC, FO, and TA groups were intravenously challenged with 0.5 μg/kg BW ultrapure LPS from E. coli serotype O111:B4 (Sigma–Aldrich: registered; product NO. L2630) on day eight. Treatments FO and TA were mixed with whole milk and were offered two times a day (at 0800 and 1700). FO and TA groups were isocaloric to compare the effect of manipulating fatty acid intake in the same level of energy intake on the APR of neonatal calves. The blood samples were collected at 1, 2, 3, 4, 6, 12, 24, 48, 72 h, post LPS challenge (p.c.) to evaluate inflammatory condition. The clinical signs (RT, RR, and HR) were recorded at 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 8, 12, 18, 24 h p.c. According to Plessers et al.'s (2015) model, the appearance of behavioral phases (respiratory, depression, and recovery phase) was assessed. Data were analyzed as a completely randomized design by using JMP (13.2) software.

The results of this study confirm previous experiments that showed a significant increase of cytokines level by the LPS administration (26, 29). As expected, the IL-6 increased when the TNF-α decreased (Maximal level at 3 and 1 h p.c., respectively). There was no significant difference in cytokines and APPs between PC, FO, and TA, while the FO had the minimum level. The typical sickness behavior of LPS-challenged calves was distinguished as respiratory, depression, and recovery phases according to Plessers et al.'s (2015) model. In this study, there was no significant effect of decreasing n-6/n-3 FA ratio on sickness behavior. Besides, the level of inflammatory cytokines and acute-phase proteins were not affected by experimental groups. These results were in line with McDonnell et al., (2019) reported no FO effect on immune function during the pre-weaning period. Although the level of DHA + EPA requirement for calves has not been well known, studies represented that their highest level in humans is 5 g/d. Stanley et al. (2007) concluded that the n-6/n-3 FA ratio might not be a helpful concept and distracts attention from increasing absolute intakes of long-chain n-3 FA. In this regard, Flaga et al. (2019) represented that DHA-rich algae supplementation in milk replacer could decrease cytokines' mRNA expression. They suggested that 3 g/d DHA might be the maximum level in neonatal calves’ diet with an appropriate effect on the immune system. In the current study, NC, PC, and TA received 2 mg/d, and FO received 3 g/d DHA. It might be worthwhile considering the amount of DHA + EPA when FO is used as an n-3 PUFA source in calves’ diet.

The results showed that decreasing the n6/n3 FA ratio in diets by supplementing FO could not affect acute phase response in calves. Besides, short-term supplementation of FO could not improve calves' immune systems as no differences in cytokines and APP between PC and FO were observed. Although sickness behavior in FO finished sooner than PC, there was no significant difference between them. In this study, increasing MUFA intake could not affect APR in calve. It seems that more studies are needed to evaluate the effect of EPA and DHA on the performance and health status of calves.

 Fodder sorghum is one of the most important forage plants in arid and semi-arid regions of the world. Maize production is low in arid and high salinity regions around the world, and sorghum due to its adaptation to arid and low water conditions, high water use efficiency, C4 photosynthetic system, high clawing power, high production capacity as wet forage, dry and Silos are a good option in these areas. In the past, sorghum was generally grown in areas that were unfavorable for growing corn, but today, with the advent of hybrid fodder sorghums, it produces under ideal conditions corn-like crops, and where moisture is a limiting factor and may have a higher yield than corn. Recently, frequent droughts in Iran have attracted the attention of farmers and livestock breeders to other forages such as sorghum, and due to the limited growing season of this forage, its use as a silo is common. Stage of growth is one of the most important factors influencing nutritional quality of fodder silages. As the fodder matures, the cytoplasmic portion of the cell reduces and the quantity of protein, lipids, soluble carbohydrates and soluble minerals decrease. Due to the drought occurrence on large parts of Iran and the adaptation of sorghum to drought conditions, a very few studies have been done on its chemical composition and nutritional value. Therefore, the aim of the present study was to investigate the effect of plant growth stage and mixing of corn and sorghum on chemical composition and degradability of corn and sorghum silage.

In order to evaluate the effects of harvesting steps and the ratio of forage sorghum blending on nutritional value and its degradability compared to corn silage, this experiment were performed using 45 experimental silos in a factorial experiment based on a completely randomize design with 15 treatments and 3 replications. Experimental groups consist of: sorghum harvest time (first factor) including: 1) before flowering (emergence of flag leaf), 2) about 10-15 percent flowering, and 3) soft seed soils. Sorghum harvested at each of the above time with forage corn with ratios of corn fodder to sorghum (second factor): 100%: 0%, 75%: 25%, 50: 50%, 25%: 75% and % 0: 100% was mixed. Silage samples were analyzed for Dry matter, crude protein, Ash and crude fat according to AOAC (2005) methods. In situ ruminal degradation kinetics parameters of DM, CP and NDF of experiment treatments were estimated using the nylon bag technique. Degradation of dry matter at times zero, 2, 4, 8, 16, 24, 48 and 72 9 hours was determined.

The results of this experiment indicated dry matter, crude protein had an upward trend with growth progression. While, the amount of crude fat, soluble sugar decreased significantly with plant growth. Ash content fluctuated during the growth stages, so that its amount was the lowest in flowering stage and was the highest during the vegetative stage (before flowering). The highest pH was observed in the soft dough stages and the mixing ratio of 25% corn and 75% sorghum, which indicates more proteolysis of silage. The lowest amount of ammonia nitrogen was observed in the soft dough phase treatment with 50% corn and 50% sorghum ratio and the highest amount of lactic acid was observed in the soft dough stage treatment with 100% sorghum, which may be due to increased soluble carbohydrate intake and convert it to lactic acid. Rapidly soluble fraction, degradation rate constant and effective degradability of dry matter, crude protein and cell wall at all passage rates increased significantly with increasing plant growth.

In general, it can be concluded that harvesting corn and sorghum forage in the soft dough stage with a mixing ratio of 25% corn and 75% sorghum improves the pH of silage. Rumen degradability of silage dry matter in the soft dough stage with different levels of corn and sorghum composition can increase feed intake in livestock. Rumen degradability of silage dry matter was also higher in the soft dough stage with different levels of corn and sorghum composition than other stages, and this can reduced feed retention in the rumen and increased feed consumption in livestock. However, more research is needed to investigate the effect of feeding a mixture of corn silage and sorghum in ruminants on voluntary feed intake and production performance.

 Ruminants require roughage in their diets to maximize production and to maintain health by sustaining a stable environment in the rumen. There is a need to identify local plants that can offer high quality forage to local ruminants. P. ferulacea (family: Umbelliferae) is a valuable forage grass found in high mountain areas of South-east Iran. Local farmers cut and wilt the plant, prior to feeding it to sheep.Sheep are selective and spend a lot of time selecting and sorting feed materials. Domestic livestock are herbivores that evolved to eat a wide array of vegetal species and typically select a diverse diet even when their nutritional requirements can be met by ingesting a single feed. A free-choice feeding method partially mimics nature and facilitates selection based on nutrient requirements that fluctuate along with feed quality and availability. Also, this method requires less use of manpower and equipment.The information available regarding the effects of ad libitum supply of concentrate and the possibility of free-choice provision of forage in lambs is very limited. Also, limited data is available concerning nutritional behaviors of lambs fed high-concentrate diets, and this information is even more limited in terms of providing feed-choice. The aim of this study was to investigate the effect of free-choice provision of two forage sources including alfalfa and P. ferulacea in addition to concentrate on digestibility and behavior of Arabian lambs.

A total of 18 male lambs of Arabic breed with an average of 90 ± 8 (SD) days of age and body weight of 19 ± 3 (SD) kg were used in the study in a completely randomized design for 45 days. Lambs were housed individually in pens (1.3 m×1.5 m) in an open shed building. Cages were separated by a metal fence with a bar design that allowed contact between animals. The animals were randomly assigned to one of the three experimental diets including free choice between; 1- alfalfa hay and concentrate, 2- P. ferulacea and concentrate, and 3- alfalfa, P. ferulacea and concentrate. The lambs were fed the total mixed rations ad libitum once daily at 0800 h and had free access to fresh water at all times.Essential oils of P. ferulacea were identified using gas chromatography–mass spectrometry. Samples taken for DM and chemical analysis were oven-dried at 55 °C for 48 h and then ground to pass through a 1- mm screen. Chemical analyses were performed in duplicate. Feed offered and refusal of each lamb were recorded daily. Digestibility was measured by total collection of feces during a 5-d period. The behavior of lambs was recorded with nine video cameras that were connected to a digital video recorder. Video recordings continuously observed visually for each lamb over a 48-h period. Recorded activities were registered together with their beginning and ending times. Data for each activity are reported as the total time, expressed in minutes, in which the lamb maintained this specific activity. Chewing behavior was divided into eating and ruminating.Intake and digestibility data were analyzed using a GLM procedure of SAS 9.2. Multiple mean comparison were carried out using Tukey's test. Animal behavior from video recordings was analyzed using a GLIMMIX procedure of SAS. Comparison. For the different statistical tests, significance was declared at P<0.05.

The compounds of α-bisabolol, β-Pinene, α-Pinene and δ-3-carene had the highest amounts among P. ferulacea essential oils. Free-choice provision of two forages increased dry matter intake and the proportion of consumed forage compared to other treatments. Forbes and Provenza (22) reported that in free-choice provision between forage and concentrate, ruminants allocate about 20% of the dry matter intake to forage. This finding is in an agreement with observed ratio of forage consumption in treatments with one forage source but is less than the observed value in the treatment with free access to two forages (36.2%). Among the mechanisms that may be involved in this increase is the greater diversity of forages that act as a stimulus for its consumption. Lambs consumed P. ferulacea as the only forage source showed higher digestibility of dry matter, organic matter, NDF and ADF compared to other treatments. Low lignin content of P. ferulacea compared to alfalfa is one of the main reasons for its higher digestibility. Lambs receiving P. ferulacea as the only source of forage had the lowest time spent eating per day compared to the other treatments. When animals were given a choice between alfalfa and P. ferulacea, the time spent eating increased significantly compared to P. ferulacea alone. Lambs that had access to two sources of forage had the lowest feeding time per gram of NDF and ADF compared to other treatments. This decrease could be due to the higher consumption of dry matter as well as NDF and ADF in this treatment compared to other treatments. Lambs that had access to two forage sources spent more time ruminating compared to the alfalfa recipient treatment. The highest duration of rumination per gram of NDF and ADF was observed in P. ferulacea treatment as the only source of forage. It has been shown that the chewing per gram of forage NDF is higher in animals with lower NDF intake (4). In this regard, Grant (24) suggested that there is an adaptive mechanism when consuming low-forage diets by increasing chewing per gram of forage NDF. Non-nutritional behaviors including self grooming, licking and biting fixed objects and laying time were not affected by treatments.

Providing two forage sources instead of one source, led to an increase in dry matter intake. The higher digestibility of dry matter, organic matter, NDF and ADF in the treatment of P. ferulacea compared to alfalfa indicates the high nutritional value of this forage. Due to the limited information available on free concentrate supply and the lack of examination of rumen and liver health indicators in the present study, any practical conclusion regarding ad libitum concentrate intake requires further research.

 The in vitro gas production test is used as a laboratory method for studying the ruminal fermentation of feed-stuffs. This method is an ideal technique, because it allows to record gas production at different hours an incubation time. In this technique, the parameters of fermentation kinetic are predicted using nonlinear models. The Exponential Model (EXP) is the easiest nonlinear model which is applied for this regard. However, it has been reported that some nonlinear models predict the parameters of gas production kinetic more accurately than the EXP model. In this study, different forages were used as feed samples and the accuracy of some nonlinear models for predicting the parameters of gas production kinetic has been studied and compared.

For this experiment, alfalfa forage (first, second and third cutting), sainfoin hay, wheat straw, barley straw and corn silage were used as feed samples. Feed samples were analyzed for Dry matter, ash, crude protein, neutral detergent fiber and acid detergent fiber according to standard methods. Rumen fluid was collected from three ruminally fistulated mature Mehraban rams before the morning feeding. Obtained rumen fluids were pooled and strained through four layers of cheesecloth into a pre-warmed (38 to 39 ˚C) insulated flask and immediately transported to the laboratory. In laboratory, ruminal fluid was filtered through four layers of cheese cloth and then mixed continuously with CO2 and maintained near 39o C before usage. To evaluate the ruminal fermentation kinetic of feeds, the in vitro gas production test was carried out during 144 h incubation time for 3 run. For this purpose, 200 mg of dried and milled feeds with 30 ml of buffered rumen fluid were poured into glass vials (in 3 replicates). Two glass vials containing 30 ml of buffered rumen fluid without substrate were considered as blanks. After capping (plus tow glass vials as blanks), all glass vials were incubated at 39 ° C. The volume of gas produced was recorded at 2, 4, 6, 8, 10, 12, 16, 20, 24, 36, 48, 72, 96, 120, 144 h after incubation.The obtained results (volume of gas produced at each incubation time) were fitted to four nonlinear models included the exponential (EXP), Gompertz (GOM), Richard (RCH) and France (FRC) models. The mean square error (MSE), coefficient of determination (R2), residual mean absolute deviation (RMAD) and mean percentage error (MPE) statistics were used as goodness of fit parameters. The run test, accuracy factor (AF), Akaike information criterion (AIC) and Bayesian information criterion (BIC) were used to compare the accuracy of the models for predicting the gas production kinetic.

The results showed that the asymptotic gas volume (A) predicted by the FRC model (104.68 ml per 200 mg dry matter) was significantly different from the EXP (100.18 ml per 200 mg dry matter) model (p <0.05). But the value of A predicted by the EXP, GOM and RCH models did not show a significantly difference. The rate of gas production (c) predicted by the studied models were significantly different and the lowest value was observed in the FRC model (p<0.05). The highest and lowest values for MSE (15.11) and R2 (0.984) were observed in the EXP model, respectively. Which indicated the EXP model goodness of fit was weak compared to the other models. The RMAD statistic in the studied models had significantly difference (p<0.05) and the highest (2.88) and lowest (0.85) values were observed in the EXP and FRC models, respectively. So, the FRC and EXP models had the highest and lowest goodness of fit, respectively. The MPE statistic in the FRC and RCH models were closer to zero (0.32 and 0.48, respectively) compared to the other models (EXP and GOM models), which indicated better goodness of fit in these models. The run test was significant in the EXP and GOM models (p<0.05). So, these models were less accurate for predicting the gas production kinetic. The value of AF, AIC and BIC statistics (2.85, 15.87 and 10.04, respectively) showed that the FRC model had the highest accuracy for predicting the gas production kinetic among the studied models.

The results showed that the EXP model had the lowest accuracy for predicting ruminal fermentation kinetic of feeds, among the studied models. However, the FRC model had the highest accuracy.

 The most important effect of using emulsifiers and l-carnitine in the diet is to help the process of digestion and absorption of fats. Improving the efficiency of metabolizable energy consumption and crude protein when emulsifier and l-carnitine supplements used in the diet indicates the positive effect of emulsifiers on the digestion and absorption of fats and other nutrients. Considering the different metabolic activities l-carnitine and emulsifier (lipidol) in broiler chickens, it seems that the use of these compounds together in low-energy diets can significantly improve the performance of broiler chickens. Therefore, the present research investigated the role of lipidol and l-carnitine supplements in reducing the negative effects of low-energy diets on growth performance, carcass characteristics, nutrient digestibility, blood biochemical parameters and meat oxidative stability of broiler chickens.

The experiment was carried out in a completely randomized design with five treatments in four replicates and 12 chickens in each replicate. Broiler chickens were fed with diets including: 1. control diet 2. Low energy diet (150 kcal/kg less than the control diet) 3. Low energy diet + 100 ppm l-carnitine 4. Low energy diet + 1 g / kg lipidol 5. Low energy diet + 100 ppm l-carnitine + 1 g / kg lipidol for 42 days. Then, the growth performance of chickens, carcass characteristics, blood biochemical indicators (total antioxidant capacity, triglyceride, cholesterol, LDL and HDL concentrations), nutrient digestibility (dry matter, protein, fat and organic matter) in starter and grower periods and meat oxidative stability 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 that there was no difference in feed intake between the birds receiving the control diet and the other diets. Weight gain and feed conversion ratio of birds were significantly improved by control diet than other treatments (P<0.05). However, birds receiving low-energy diets containing lipidol + l-carnitine had the same feed conversion ratio (1.79) as birds receiving the control diet (1.75). Birds fed with low-energy diets containing lipidol and lipidol + l-carnitine had better weight gain and feed conversion ratio than birds fed with low-energy diets containing l-carnitine and without additives (P<0.05). Compared to the control treatment, the birds that were fed with low-energy diets containing lipidol and l-carnitine separately and together had a lower abdominal fat percentage (0.4%) (P<0.05). Also, birds fed with the control diet showed a tendency to increase the heart percentage compared to other experimental treatments (P=0.06). Birds fed with low energy diets containing lipidol and lipidol + l-carnitine had higher dry matter (3.6%), protein (7.8%) and fat (6.6%) digestibility in the starter period and higher digestibility of dry matter (6.9%) in the grower period compared to other treatments (P<0.05). In general, in the starter period, the birds fed with control diet showed lower digestibility of protein (P=0.06) and fat (P<0.05), and in the growth period, the digestibility of dry matter was lower than the birds fed with other diets. Birds that were fed with low energy diets containing lipidol and l-carnitine separately or together had higher total antioxidant capacity compared to birds fed with control diet and low energy diet without additives (P<0.05). Also, birds that were fed with low-energy diets containing l-carnitine and lipidol + l-carnitine had lower blood triglyceride (P=0.05) cholesterol and LDL concentrations compared to birds fed with control diet and low-energy diet without additives (P<0.05). Birds fed with low energy diet containing lipidol + l-carnitine increased blood HDL level compared to birds receiving low energy diet without additives (P<0.05). Birds that were fed with low-energy diets containing lipidol and l-carnitine separately and together had lower concentrations of malondialdehyde in thigh and breast meats on days 3, 6 and 9 after slaughter and kept in a refrigerator (4ﹾC) compared to birds fed with low energy diets without additives and control diet (P<0.01). 

Finally, the simultaneous utilization of 100 ppm l-carnitine and 1 g / kg lipidol in low-energy diet showed similar growth performance when compared with control diet and led to improved carcass quality, fat, protein and dry matter digestibility, blood lipid parameters and meat shelf life of broiler chickens.

 The increase in the cost of the diet, especially the protein part, has caused the desire of producer and researchers to use by-products. The use of animal waste not only reduces the cost of feed but also reduces the entry of contaminants into the environment. Hydrolyzed feathers, meat meal, bone meal, poultry by-product meal (PBM) and fish oil are some of the by-products used in poultry, dairy cattle and other livestock diet. Also, the use of pelleted feed in broiler chicken is increasing, because it produces less dust, improves digestibility, reduces transportation costs, and improves performance indicators such as feed consumption and decrease feed conversion ratio. Sodium bentonite (SB) is one of the substances that has been used as pellet binder in feed. Several studies have evaluated the effects of the addition of SB and had beneficial results on pelleting physical properties such as pellet durability index (PDI) and pellet hardness. Addition of active SB as a pellet binder in wheat-soybean meal-based diets has increased the relative electrical energy usage (REEU) and decreased the feed conversion ratio. However, studies on the use of different levels of PBM and SB as a pellet binder in broiler chicken diets are very limited, the aim of the present study was to investigate the effects of pellet binder levels of SB in diets containing different amounts of PBM on performance, carcass traits and blood metabolites of Ross 308 broiler chickens in finisher period.

Treatments were assigned in a completely randomized design based on a factorial arrangement of 3 levels of SB conditioning time (0, 1.5 and 3%) × 3 levels of PBM (0, 5 and 10%). Experimental diets were balanced based on Ross 308 recommendations for finisher period (24-42 d) by using UFFDA software. In the present experiment PBM and pellet binder of SB samples were prepared from MegaFaravar Co., Iran. Ingredients of diets were ground through a 2-mm screen size in a hammer mill. All diets mixed in a double-shaft mixer and transferred to super conditioner with 82◦C for 10s, and then pelleted through a 3-mm die. After pelleting of feed produced, 3 replications of each treatment with 3-minute intervals were sampled from the cooler part of the pellet machine. The PDI, hardness test and REEU related to experimental diets was measured. Also, a total of 360 24-day-old male chicks were individually weighted and allocated to 9 treatments of 4 replicates (10 birds in each replication). Feed intake (FI), average daily gain (ADG) and feed conversion ratio (FCR) were recorded. On 42 day, 2 birds per pen were randomly euthanized by cervical dislocation. Carcass characteristics and relative weight of small intestinal segments were measured. Total protein, glucose, albumin, lipoproteins (HDL, LDL) were determined by using autoanalyzer device and commercial kits.

Addition of 1.5% SB improved and the use of PBM due to its high fat content reduced the quality characteristics of the pellet that due to their strong colloidal properties and giving rise to a thixotropic gelatinous substance. Likewise, different levels of SB as a pellet binder and PBM did not change the ADG and FCR (P <0.05). However, the use of different levels of PBM with and without SB reduced FI (P<0.05). Also, the relative weight of carcass, breast and thigh was not affected by experimental treatments (P <0.05). Abdominal fat increased significantly in the groups receiving PBM (P <0.05). Amino acid imbalances in PBM probably increase deamination and conversion of amino acids to fat. Significant reduction in duodenum and ileum length was observed in the group containing 3% SB and 10% PBM (P <0.05). Also, the level of 10% PBM with and without SB increased the concentration of blood lipids. Blood lipids concentration have a positive correlation with weight and feed as an environmental factor affects its amount.

In general, the results of this experiment showed that application of PBM as a source of protein with adequate nutritional value up to 5% without negative effects on performance for use in pelleted diet of broilers at high levels when soybean meal is expensive and or not available, it is possible and useable. Also, commercial sodium bentonite can be used as a pellet binder to increase the quality of pellets up to 1.5%. The need for further studies on the simultaneous use of sodium bentonite as a pellet binder and PBM are recommended to ensure the results obtained in other broiler chicken breeding periods.

 Feed cost has gradually increased in poultry production worldwide. One approach to minimizing production cost is dietary manipulation of nutrient supplies through improved feed efficiency. The inclusion of lipids in broiler diets is essential to meet metabolisable energy requirement. Great amounts of animal fats and vegetable oils are usually added to broiler diets to increase their energy content. However, several factors can affect lipids digestion, both related to the animal characteristics such as bird age, genetic strain, secretion and activity of digestive enzymes, and to the diet composition such as type of fat used as lipid supplement, ratio of unsaturated to saturated fatty acids in the diet, presence of pentosans and dietary fiber. Within this reality, researches have been conducted to study the increased digestibility of oils and fats by emulsifying substances, such as bile salts and phospholipids. Lysophospholipid (LPL) is a more effective biosurfactant in emulsifying properties than bile salts and soy lecithin because one molecule in the hydrophobic tail is removed, indicating more stability in the aqueous environment of the gastrointestinal tract. Another action of lysophospholipids is related to the antibacterial effect. They may modify the biological structure of bacteria causing changes in membrane permeability, raising the speculation of a combined effect with organic acids on poultry gut health. The changes in membrane permeability by lysophospholipids may facilitate the ion dissociation of the organic acids inside the bacteria. In turn, the control of the intestinal microbiota through these additives could preserve the integrity of endogenous, consequently, the present study was designed to investigate the effects of dietary LPL supplementation in diets differing in fat on blood parameters, intestinal morphology, ceca microbiome and performance in broiler chicks.

This experiment was performed in a completely randomized design based on factorial arrangement to evaluate the effect of lysophospholipid supplementation (0 and 0.25g/kg) in corn-soybean meal diets containing three fat sources (soybean oil, tallow and their blend 50: 50%) and each at two levels (1.5 and 3%) with 12 isocaleric and isonitrogenous starter diets. Each diet was fed to six replicates of 10 chicks each during 1 to 14 days of age. Performance traits, jejunal morphology, serum lipid composition, cecal microbial population of one chick from each replicate were measured at day 14.

the interaction effects of lysophospholipid supplementation, fat source and fat level were not significant on broiler performance during 1 to 14 days of age, except for the lysophospholipid supplementation and fat level that was significant on feed intake in the starter period. Among the main effects only fat levels had a significant effect on body weight, body weight gain in the starter period, and 3% fat level compared to 1.5% improved body weight and body weight gain. These results are in agreement with zampiga et al, (2016) that demonstrated the addition of the lysophospholipid did not statistically improve final body weight and daily weight gain of broilers in the whole period of trial (0–42 d). These observations are partially in contrast with Melegy et al. (2010) who reported that the use of an emulsifier based on lysolecithin at the dosage of 0.25 or 0.5 kg/ton of feed significantly improved these productive parameters. Other factors may be affect on broiler performance such as inappropriate dose of lysophospholipid in diet, low energy levels of the experimental diets, use of 3 factors in the experimental design, and low bird population in each treatment that combined the effects. The Interaction effects of lysophospholipid supplementation, fat source and fat level were not significant on jejunal villus height, villus width, diameter of epithelium layer, crypt depth and villus height to crypt depth ratio. The interaction effects of lysophospholipid supplementation and fat levels in diet showed a significant effect on villus width. The effect of fat levels was significant for villus height and it increased by the use of 3% levels. The Interaction effect of lysophospholipid supplementation, fat source and fat level was not significant on the concentration of triglyceride, cholesterol, HDL and LDL in serum of broiler chicks. The interaction effect of lysophospholipid supplementation and fat level in diet was significant on the concentration of triglyceride level, and the interaction effect of lysophospholipid supplementation and fat source in diet was significant on LDL in serum lipid level of broiler chicks. The main effect of lysophospholipid supplementation was significant on the concentration of triglyceride, and also the effect of fat source was significant on cholesterol and HDL in serum of broiler chicks. The Interaction effects of lysophospholipid supplementation, fat source and fat level was not significant for lactobacillus and E-coli population in ceca. The main effect of lysophospholipid supplementation was significant increase on the lactobacillus population in ceca, and the effect of fat level in diet was significant decrease on the E-coli population in ceca.

It can be concluded in this study that of lysophospholipids supplementation did not have a significant effect on performance in broiler chickens during the starter period.

 Rooster’s reproductive performance is an indispensable component of breeder production because it plays a vital role in the maximum production of fertilized eggs. Existence feed supplement in the poultry industry, intermediary metabolites have been including in the diet to improve fertility and reproductive outcomes. Carnitine (β-hydroxy-γ-trimethylaminobutyrate), vitamin-like-amino acid, is a quaternary ammonium compound, that has multifunctional roles in reproduction. High concentrations of L-carnitine (LC) are present in epididymal lumen, where it participates in sperm energy balance and the maturation of spermatozoa. In light of previously reported breeder birds supplemented with dietary LC have shown improvements in semen traits and fertility parameters. The present study is an attempt to investigate the effects of several levels of dietary LC supplementation on semen quality parameters and gonadosomatic and hepatosomatic indexes at maturity and production peak.

For the present experiment, thirty-six Ross (12-week-old) breeder broilers were used for 22 weeks in a completely randomized design with three treatments (0, 250 and 500 mg L-carnitine in kg of diet) and twelve replications. All roosters were fed standard isocaloric (2754 kcal/kg) and isonitrogenous diet (12 % protein). The birds for 22 weeks in a completely randomized design with three treatments (0, 250 and 500 mg / kg of LC in the diet) and six replications were used. During the adaptation period (21-24 weeks of age), the roosters were trained by abdominal massage for semen collection. After the experimental period was commenced (24 weeks of age), semen samples were collected and evaluated for seminal attributes every two weeks (from week 24 to week 34). The following parameters were determined immediately after the semen collection; to measure the semen samples were collected weekly to evaluate semen volume, total motility, membrane functionality, mitochondria activity parameters. Also, to determine gonadosomatic and hepatosomatic indexes at 24 and 34 weeks of age, six birds in each treatment weighing then were slaughtered and immediately the testes and liver were removed and weighed.

The highest sperm motility (96.60%) was observed in birds fed 250 mg LC (P <0.04). By increasing the level of LC in the diet, sperm membrane functionality improved linearly (6.8% increase compared to control) (P <0.04). A linear trend (P = 0.06) was observed in mitochondrial activity with increasing levels of LC in the diet (69.31, 72.00 and 76.25). LC plays an essential role in energy metabolism by carrying over fatty acids in the mitochondria matrix for β-oxidation producing energy. Therefore, it provides a better supply of energy for spermatogenesis and normal physiology of sperm, are presumably improved by an optimum level of LC, as a result, sperm concentration and live. These data provide evidence that LC can be effectively used in diets up to 500 mg/kg of diet or 30 mg/kg of body weight /day for semen improvements of rooster’s breeder. At 24 weeks of age, the changes in gonadosomatic index (0.55, 0.68 and 0.64) were affected by different levels of LC (P <0.01). During testis development in the chicken (from 2 to 15 weeks of age), there is no significant increase in testicular weight, however, the early stage is the most important period for testicular development. The mature testis has seminiferous tubules with a multilayered epithelium representing the different stages of spermatogenesis. Sexual maturity is associated with the highest testes weight and consequently with the highest plasma concentration of reproductive hormones. Gonads of the mature male broiler breeder are organized into separate, comfortably discernible cellular correlations and functional compartments. It has been accepted that steroid hormones biosynthesis and generation of spermatozoa are two major actions that the testicles fundamentally carry out. The improvements in gonadosomatic Index of roosters observed in this study in response to dietary LC may be attributed, at least partly, due to improved utilization of dietary nitrogen, achieved through more efficient fat oxidation by LC. Testicles contain the seminiferous tubules and the interstitial space. Seminiferous tubules are the functional elements of the testis and sertoli cells are the principal structural basis of the seminiferous epithelium, inhabiting on the substratum membrane.

The addition of 250 and 500 mg of L-carnitine to the diet due to the increase in gonad index led to an improvement in sperm quality parameters at the beginning of the production period (puberty).

 The main aim of dairy farms is to increase the economic milk production of each cow in each lactation period. Therefore, the effective genetic and environmental factors should be identified and evaluated. Today, the main cause of economic losses to dairy herds is low reproductive efficiency. Any factor that causes delay or non-pregnancy of dairy cows leads to reduced milk production and calf birth. Stress is known as a major factor in reducing of fertility of dairy farms. Therefore, it is necessary to find management solutions that can reduce the side effects of this factor. The objective of this study was to evaluate the effect of insemination in pre- and post-milking time on pregnancy rate of Holstein Cows in Isfahan province. 

This research was conducted in the winter season between 2015 and 2020 in two large industrial herds in Isfahan. 2340 Holstein cows with 1 to 5 lactations were studied. The cows were randomly divided into two equal groups. According to the time of estrus observation and calculation of insemination time, half of the cows (1170 heads) were inseminated during 2 hours after milking and the other half during 2 hours before milking. Statistical analyzes were done using SAS software version 9.4. Descriptive statistics were estimated for enumerated data with frequency procedure (Proc FREQ) and for continuous data with mean procedure (Proc MEANS). Logistic regression method (Proc GLIMMIX) was used to analyze the results of insemination (1 = lead to pregnancy and 0 = no lead to pregnancy). The final model was including the fix effects of herd-year-season, insemination time compared to milking (pre- and post-milking), age at insemination time (2 levels including less equal and more than 40 months), MIM (nine levels), interaction effect of insemination time and age, interaction effect of insemination time and milk yield level (low and high producing) and the random effect of semen as bulls.

Odds of pregnancy of inseminated cows in the post-milking time was more than inseminated cows in the pre-milking time (1.5 times). Also, in the group of high producing cows (with a milk average yield of more than 51 kg) and low aging cows group (less equal 40 months), the odds ratio of pregnancy of post-milking insemination was estimated higher than pre-milking insemination (1.6 and 1.85, respectively). Comparison of least squares mean (LS Means) of pregnancy rate in cows based on the time of insemination showed that in generally there is a 0.09 pregnancy difference between insemination time in pre- and post-milking. The mean of pregnancy rate in pre- and post-milking insemination was 0.31 and 0.40, respectively. Due to be significant of the odds ratio in the group of high producing cows (with a milk average yield of more than 51 kg), comparison of least squares mean of pregnancy rate in insemination times showed a difference of 0.1 in this group. The mean of pregnancy rate of high producing cows in pre- and post-milking insemination was 0.30 and 0.40, respectively. Also, due to be significant of the odds ratio in the group of low aging cows (less than equal to 40 months), the difference of least squares mean of pregnancy rate at insemination times was estimated 0.15. In other words, the mean of pregnancy rate of low aging cows in pre- and post-milking insemination was 0.34 and 0.49, respectively. For low producing (less than 51 kg) and high aging cows (more than 40 months), although the mean of pregnancy rate at insemination time of post-milking was numerically higher than pre-milking, no significant difference was observed. Although there is a little information for the physiological factors of higher pregnancy in cows that have been inseminated in post-milking, it seems that reducing stress and consequently lower cortisol concentrations due to discharging milk of udder can be an effective factor. 

The results of this study showed that the time of insemination based on milking time makes a significant difference in the pregnancy rate of Holstein cows. It was also found that high producing cows with a milk average yield of more than 51 kg and low aging cows with age of less than equal to 40 months had the maximum chance of pregnancy at the time of insemination of post-milking due to reduced effect of milking stress at insemination time. Although the physiological reasons need to be carefully investigated, the findings of this study can be recommended as a suitable solution for insemination of low aging and high producing cows to increase herd fertility.

 To characterize the affection of tempo and temperature with chill and without chill, as storeroom status for fecund eggs formerly to their incubation, you have to resort to a series of processes. What starts as a fertile egg on the breeder farm must end up being a healthy chick on the broiler farm. After the hen lays the egg, its quality can only worsen, it will never be the same, so we must pay attention to the transit between the laying of the hatching egg and the start of the incubation. Most of the causes that can influence the variability of hatchability or quality losses of the chick are caused by inadequate management of the egg handling processes before being hatched.  Inadequate temperature and humidity control generally produce poor results. Inadequate control means that the temperature or humidity is too high or too low for long enough to interfere with the normal growth and development of the embryo. Poor results are also given due to inadequate ventilation, the inappropriate egg turns, and poor sanitation of machines or eggs. Obtain the best hatching by maintaining the temperature at 37.7 ◦C throughout the incubation period when using a forced-air incubator. Minor temperature fluctuations (less than ½ degree) above or below 37.7 ◦C are tolerated but do not allow temperatures to vary more than one degree. Prolonged periods of high or low temperatures will alter hatching success. High temperatures are especially dangerous. A forced-air incubator that is too hot tends to hatch early. One that is kept constantly cold tends to produce late hatching. In both cases the number of chicks that hatch will be reduced. Keep the air incubator still at 38.8 ◦C to compensate for temperature stratification within the incubator. Obtain the proper temperature reading by raising the thermometer bulb to the same height as the top of the eggs, when the eggs are placed horizontally.  If the eggs are placed upright, raise the thermometer bulb to a point that is 0.6 to 1.2 cm and below the top of the eggs. Temperature is measured at the level where the embryos develop (at the top of the egg). Do not allow the thermometer bulb to touch the eggs or the incubator.

A total of 720 eggs were taken at accidental from one-day operation. . There were also questions about the health and management of laying hens, including nutrition, disease and vaccination. In Ilam province, there is no hatchery and laying hen factory for hatching purposes. Behind having been chosen by their exterior characteristic and weight, the eggs were divided into 2 cures, previously the storeroom: In each cure, there were organized three groups of 120 eggs each, with 4, 7 and 10 days of storeroom respectively.

The biological control took away: 1st inspection, at 6 days and 2nd inspection at 11 days (embryonic fatality, embryos with patulous, allantoides and embryos with shut allantoides) incubation ultimate, consequences. The consequences exhibit, that as for the embryonic fatality, the best conduct was made at the 4 days of the storeroom with the chill. The higher values communicated, to 10 days of storeroom without the chill. The best consequences for the prime category, chicks and whole born were in group one. Improper management in the use of incubators was another factor that contributed to the decline in the birth of first-class chicks. These defects in the work management of the incubator reflected high mortality between the ages of five and 18 days. In this case, as shown in table (3), fetal mortality rates on the 11th day were significantly lower and no significant differences were observed between them.

It was concluded that storeroom without chill during 4 days touch to 5.5% the prime category, chicks taking. The eggs storeroom during 7 and 10 days without chill borne victims for the significance of embryonic fatality, of 20.5% and 75.8% respectively. Keeping fertilized eggs at normal room temperature during the first four days that caused fetal mortality in the first stage of incubation was up to five and a half percent effective in obtaining first-class chicks. We can use various techniques to make a “clean” egg look like, but what we do is risk making things worse. Sandpaper, sponges, damp cloths are used on farms to make them look clean but quickly contaminated. So we just make them look clean In addition to contaminating them, we cover pores, making the incubation process more difficult for the embryo. Laying or dirty eggs that are washed present hatch rates of up to 20% less than those that are clean and up to 7 times more chick mortality at the end of the first week.