فصلنامه پژوهشهای تولیدات دامی
پیاپی 38 (زمستان 1401)

By increasing the poultry and broiler production industry, concerns for  having a food free of pathogens, and as a result, producing a quality and healthy product are increasing. Therefore, correct and efficient disinfection of poultry diets with maintaining the quality of them is very important. The aim of this study was to investigate the effect of gasification of complete poultry feed by ozone on microbial papulation and the quality of broilers diets.

From 432 commercial male Ross strains in a 2 × 2 factorial experiment with three levels of ozone gas (zero, 20 and 30 ppm) and two levels of low fat (1.5 and 2% vegetable oil for growth and finishing periods respectively) and high fat (3 and 4% of vegetable oil for growth and finishing periods, respectively) were used in a completely randomized design with 6 treatments and 4 replications. Diets were ozonated for 120 minutes at concentrations of 20 and 30 ppm. Aflatoxin B1 levels, microbial papulation and the presence of fungi in the feed as well as oxidation of feed lipids in broiler chickens were assayed  after ozonation.

Aflatoxin B1 was not found in grower and finishe diets. The lipid oxidation in ozonated diets with 30 ppm was significantly higher than non-ozonated diets (P<0.05).

According to the results of this experiment, the use of ozone gas to disinfect the broiler chickens diets, despite the destruction and inactivation of microbes and fungi, increases the oxidation of dietary fats.

The addition of phytase enzyme to poultry diets is necessary due to its inability to produce phosphorus from plant phytate. In this study, for the first time, the recombinant probiotic Saccharomyces boulardii which is producing recombinant phytase (produced domestically) was used as a dietary supplement. Therefore, the aim of this study was to compare the effect of two types of phytase enzymes in wheat and corn-based diets on growth performance, cecum microbial population, carcass and bone characteristics of broilers.

This study was done using 672 equal mixed male and female Hubbard Flex broilers in a completely randomized factorial design (4 × 2 factorial arrangement) with 6 replications containing 14 chickens in each replicate. Eight experimental treatments were as follows: two separate control treatments based on corn or wheat diet, two treatments containing phytase enzyme derived from recombinant Saccharomyces boulardii (500 FTU) based on corn or wheat diet, two treatments containing wild type Saccharomyces boulardii based on corn or wheat diet, and two treatments containing Hostazym P 10000 (500 FTU) based on corn or wheat diet.

Broilers treated with corn diet containing recombinant phytase enzyme had significantly more weight compared to hostazym treated broilers at 10 days of age (p≤0.05). Also, all three types of dietary additives significantly reduced feed intake and feed conversion ratio in broilers compared to the control group at 41 days of age (p≤0.05). The relative weight of gizzard of chickens fed corn-based diets was higher than wheat-based diets (p≤0.05). Both recombinant and non-recombinant Saccharomyces boulardii treatments were able to reduce the relative weight of the heart in two diets based on corn and wheat, but this reduction was significant only in non-recombinant yeast. Also, chickens treated with corn-based diets containing recombinant phytase and the control group had the lowest and the highest relative weight of jejunum, respectively, among all treatments. The results of the microbial population showed that the wheat-based diet reduced the overall microbial population compared to the corn-based diet (p≤0.05). Also, recombinant and non-recombinant Saccharomyces boulardii treatments significantly reduced the bacterial population in the cecum of broilers. Phytase enzyme from recombinant yeast increased retention of calcium, phosphorus, magnesium, and potassium and also increased tibia bone resistance compared to other experimental treatments (p≤0.05).

The findings of this study showed that the phytase enzyme reduced feed intake and improved the feed conversion ratio in broilers. Also, phytase enzyme decreased jejunum weight but only recombinant and non-recombinant yeast treatments led to a significant reduction in the microbial population. The results of increasing the percentage of elements stored in the tibia and tibia resistance showed the superiority of recombinant phytase enzyme compared to commercial phytase (hostazym). Due to the lack of effect of grain type on yield traits, domestic wheat can be a good alternative to corn.

Bacillus coagulans is a new strain of the probiotics group that in addition to being spore-forming, stimulates the secretion of lactic acid in the digestive system.This experiment is performed to assess the effect of Bacillus Coagulans on the functional traits and microbial flora of the gastrointestinal tract of Ross 308 broilers.

In order to assess the effect of Bacillus coagulans probiotic supplement on the feeding of broiler chicks, an experiment is conducted on 960 chicks including 12 replications of 20 chicks. The nutritional periods consist of starter (1-10 days) , grower (11-25 days) and finisher (26-42 days). To implement the experiment , The experiment was conducted on Ross 308 male chicks with average weight of  40±0.12 gram and in a completely randomized manner in four treatment groups. Experimental groups are 1) basal diet without consuming bacillus coagulans, 2) basal diet with adding probiotic supplement at the rate of 400 g/ton feed in starter and grower periods and 200 g/ton feed in finisher period, 3)basal diet adding probiotic supplement at the rate of 400 g/ton feed in starter and 200 g/ton feed in grower and finisher period and 4) basal diet adding probiotic supplement at the rate of 200 g/ton feed in starter, grower and finisher periods. Production traits consisting of body weight gain, feed intake and feed conversion ratio are measured at the end of each period of starter, grower and finisher. On days 7 and 40, two chicks from each replicate are slaughtered using carbon dioxide gas and the cecum was isolated. The samples sent to the laboratory under specific protocols to count clostridium perfringens, E.coli, salmonella, streptococcus and lactobacillus. Furthermore, the cloaca temperature of all the remaining chickens of the experiment project is measured on the day 40 of experiment. Total excreted nitrogen and pH of litter contents are measured on the day 40.

Consumption of Bacillus coagulans had no meaningful effect on weight gain of chickens up to 42 days of age, but compared to the control group, the groups that consumed Bacillus coagulans showed higher weight gain. In the starter and final period, consumption of Bacillus coagulans led to the reduction of feed intake (p≤0.05). At day 42, groups that consume Bacillus coagulans had lower conversion rates than control group. Adding Bacillus coagulans to the diet of broilers at day 40 had a meaningful effect on increasing the population of lactobacilli1 (p≥0.05). On the other hand, consumption of Bacillus coagulans reduced the bacterial population of Clostridium, Streptococcus and Escherichia coli (p≥0.05). The results of this experiment show that broilers receiving Bacillus coagulans produced lower rate of nitrogen fecal escape than control group (p≥0.05). Additionally, the use of this bacterial compound in the diet of broilers reduced the cloaca temperature of chickens compared to the control group (p≥0.05). Adding this bacterium to the diet of broilers had no effect on pH litter (p>0.05).

The achieved results of this research indicated that dietary supplementation with Bacillus coagulans led to increase body weight gain and decrease FCR , balances the beneficial microbial population of the gastrointestinal tract, reduces gastrointestinal inflammation and improves digestibility.

This experiment was designed to investigate the effects of sunflower seed meal fermented with Aspergillus niger and the probiotic Saccharomyces cerevisiae on the morphology and microbial population of different parts of the intestine and some digestive parameters.

This experiment conducted as a completely randomized design with 200 one-day-old Ross 308 male commercial broiler chicks, in five treatments five replications and eight chickens per replication. Experimental treatments including: 1- Diet containing sunflower meal fermented with Aspergillus niger 2. Diet containing sunflower meal fermented with Saccharomyces cerevisiae 3- Diet containing sunflower meal fermented by both Aspergillus niger and Saccharomyces cerevisiae 4. Diet containing unprocessed sunflower meal 5- Control diet based on corn and soybean. The effect of treatments at the end of the 39-day raising period was investigated on the morphology of ileum, viscosity, microbial population and pH contents of broiler chick’s intestine.

Intestinal morphological results showed that the highest villus height and the ratio of villus height to crypt depth in ileum were related to birds fed fermented treatment with Aspergillus niger (p<0.05). The amount of viscosity in the jejunum and ileum of the small intestine in all three treatments contained fermented sunflower meal was higher than the treatment contained unprocessed sunflower meal (p<0.05). The treatment contained sunflower meal fermented with Aspergillus niger was the closest to the control treatment based on corn and soybean (p<0.05). The population of duodenum coliform increased significantly in the treatment contained sunflower meal fermented by Aspergillus niger (5.41) and also the treatment contained sunflower meal fermented by both fungi and yeast (5.35) compared to the control treatment (5.57). The highest population of aerobic bacteria in this section was related to the treatment contained sunflower meal fermented by Saccharomyces cerevisiae (5.45): (p<0.05). The highest populations of Lactobacillus and aerobic bacteria in the jejunum were related to the treatment contained sunflower meal fermented with Aspergillus niger (5.16) and the control treatment based on corn and soybean (6.49): (p<0.05). The highest population of Lactobacillus bacteria in the ileum was related to treatment contained sunflower meal fermented with Aspergillus niger (5.92) and treatment contained unprocessed sunflower meal (5.95): (p<0.05). Also, the highest population of coliform (5.43) and aerobic bacteria (7.61) in this part was related to the treatment containing sunflower meal fermented with Aspergillus niger (p<0.05). The population of coliform, lactobacillus and aerobic bacteria in cecum was higher in all treatments than the control treatment based on corn and soybean (p <0.05). The highest pH of duodenum and jejunum was related to control treatment based on corn and soybean (p<0.05).

The results of this experiment indicated that fermented sunflower meal with Aspergillus niger and Saccharomyces cerevisiae decreases the pH of the gastrointestinal tract contents, increases the total microbial population, decreases coliform and increases Lactobacillus and improves the intestinal morphology of broiler chicks.

In the recent years, many countries have banned or restricted the usage of antibiotics as growth-promoting, due to their undesirable effects on human and animal health. Using probiotics as an alternative to growth-promoting antibiotics play an important role in improving performance, health and increasing the quality of poultry products. Lactobacilli are the most popular probiotic bacteria that have beneficial effects on host’s performance and health. In this study, the effect of two native strains of Lactobacillus ruteri isolated from the gastrointestinal tract of native chickens in north-western and south-western of Iran were investigated on performance, carcass characteristics, blood parameters and immune response of broilers.

In this experiment, 300 Arbor-Acres® Plus+ male broiler chickens were divided in to 5 treatments, 4 replications (15 chickens per replication), in a completely randomized design. The experimental treatments include: 1- Basic diet as a control treatment, 2- Basic diet + Avilamycin antibiotic, 3- Basic diet + commercial probiotic (Bio-Poul®), 4- Basic diet + Lactobacillus reuteri isolate MG547731 (Plr2), and 5- Basic diet + Lactobacillus reuteri isolate MG547727 (Plr3).

Under the condition of this experiment, commercial probiotics, antibiotic and either Lactobacillus reuteri (Plr2) isolates, significantly improved daily weight gain in final period (p<0.05). Native isolates probiotics and commercial probiotics significantly (p<0.05) reduced the relative weight of gizzard and proventriculus, though no significant (p<0.05) differences were recorded for other carcass components in broiler chickens. After the first injection of SRBC, treatments include antibiotic and Lactobacillus reuteri (Plr2) isolate caused a significant increase of IgM, and after the second injection, Lactobacillus reuteri (Plr2) and commercial probiotic treatments, showed a significant (p<0.05) increase in immunoglobulin G and Total immunoglobulin. The antibody titer against Newcastle vaccine did not show a significant difference between treatments and the control group. There was no significant difference between serum glucose, cholesterol, triglyceride, VLDL and LDL between treatments and the control group. No significant difference was obtained in serum HDL level in probiotic treatments, while antibiotic treatment appeared with a significant decrease in HDL.

Addition of native Lactobacillus reuteri isolates to poultry diets can have beneficial effects similar to commercial probiotics, on performance, immune response and blood parameters of broilers.

With the increasing development of broiler industry, increasing feeding costs and concerns, environmental pollution caused by nitrogen and phosphorus disposal, finding ways to increase the bioavailability of nutrients, including phosphorus, is of great interest. The purpose of this experiment was to investigate the effect of the combination of phytase and synbiotic in phosphorus deficient diets on the performance of broiler chickens.

360 one-day-old broiler chickens of Ross 308 strain were used in a completely randomized design with 5 treatments, 4 replications and 18 birds per replication. The birds were fed with the same rations in the first seven days and the experimental diets were given to them from the age of 8 days. Experimental treatments include 1- Control group (diet containing recommended levels of phosphorous), 2- Diet with phosphorus level less than recommended (75% recommended; low phosphorus diet), 3- Low phosphorus diet + phytase, 4- Low phosphorus diet + Synbiotic, 5- Low phosphorus diet + Synbiotic + phytase. Body weight and feed intake were measured in each period and daily weight gain and feed conversion ratio were calculated. At the end of the period, low density serum  cholesterol concentrations, high density poprupe (HDL) and low density poprupe L (LDL) and alanine aminotransferase (ALT) enzymes were measured.

During growth period (24-7 days), the weight gain of birds that received phytase, synbiotic and synbiotic diets with phytase was higher than birds fed control or phosphorus deficient diets and these birds had higher live weight (P<0.05). There was no difference in carcass yield and relative weight of liver and ventricular fat between treatments. Experimental treatments had no effect on serum concentrations of cholesterol, HDL and LDL and alanine aminotransferase (ALT) in broilers. The level of triglyceride in the blood of birds fed phosphorus-deficient diets was lower than that of birds fed control diets containing synbiotics or synbiotics + phytase (p<0.05).

The use of synbiotec + phytase in phosphorus-deficient diets, while reducing the need for phosphorus mineral source, improves the growth performance of broilers and also reduces phosphorus excretion into the environment.

 Optimal nutrition occurs only when poultry efficiently use the nutrients in the feed for growth, health, reproduction and survival. Vitamins should be present in sufficient amounts in the diet due to their vital functions in the animal's metabolism and the optimal utilization of other nutrients.

Five hundred one-day-old 308 Ross strain chicks (male and female) were distributed in a completely randomized design with 5 treatments, 5 replications and 20 chicks per replication. Dietary treatmets are included five levels of vitamin supplementation: 1) control (100% recommended values of strain Ross 308 catalog), 2 to 5) 90%, 80%, 70% and 60% recommended values. During the 42 days of the experimental period, performance was recorded at the end of each period (ages 10, 24 and 42 days). Evaluation of humoral immune response was performed using SRBC injection at 35 days of age. Cellular immune response was assessed at 37 days of age by hypersensitivity test. At 42 days of age, ten birds per treatment were bled to count white blood cells and then the birds were slaughtered, and the relative weights of different parts of the carcass were measured.

The suggested level of 80% vitamin supplement had no significant effect on performance including feed intake, FCR, survival percentage and production index (p<0.05). By reducing the level of vitamin supplement, the length of jejunum and the percentage of wings and spleen decreased in the experimental treatments (p<0.05), but the percentage of carcass and other components were not affected (p>0.05). Antibody titer in response to SRBC injection, cellular immune response and the number of white blood cells were not affected in level of 80% vitamin supplement, although the level of 80% vitamin supplement significantly reduced IgG titer and heterophil percentage (p<0.05).

In general, the results showed that it is possible to reduce the level of vitamins in the diet of broiler chickens by 20% without negatively affecting the performance and responses of cellular and humoral immunity.

The aim of this study was to investigate the effect of sodium acetate and conjugated linoleic acid on dry matter intake, body weight, activity of liver enzymes and blood metabolites in fresh cows.

This study was performed to investigate the effect of sodium acetate and conjugated linoleic acid on dry matter intake, body weight, liver enzyme activity, milk production and blood metabolites in newborn cows. Materials and Methods In this study, 24 Holstein cows with an average initial weight of 601.47±13 kg and a body condition score of 3.64±0.21 were used for 25 days during days 5-30 postpartum. This experiment was performed in 3 treatments and 8 replications in a completely randomized design by comparing the means by the mean least squares method at a significance level of 0.05. Treatments include 1- control with a source of calcium salt of palm fat, 2- Diet containing 300 g of sodium acetate supplement, 3- Diet containing 100 g of conjugated linoleic acid supplement (50% cis-9 trans-11CLA, 50% trans-10 cis-12 CLA) was. Dry matter intake and milk production were recorded daily, body weight and body condition score at the beginning and end of the experiment. Blood samples were also taken on days 5, 7, 14, 20, 25. The cows were milked in three meals of morning, evening and night, and the record of each meal was recorded. In order to measure milk composition, milk samples were taken on days 5, 8, 11, 14, 17, 20 and 25 after calving.

The results showed that the mean body weight, body condition score and dry matter intake were not significantly different between treatments. The concentration of non-esterified fatty acids was not affected by the treatments. Also, no significant differences were observed for triglycerides, cholesterol, albumin, total plasma protein and blood urea nitrogen between treatments. Plasma glucose concentration was significantly different between treatments (p<0.05), however, CLA and sodium acetate significantly increased and decreased compared to the control) (p<0.05. Sodium acetate significantly reduced the levels of aspartate aminotransferase and lactate dehydrogenase compared to control and CLA treatment (p<0.05). Daily milk, corrected milk production of 3.5% fat and milk fat percentage were significantly different between treatments, and sodium acetate and CLA treatments significantly increased and decreased milk fat percentage, respectively, compared to the control (0.05). Also, milk fat production increased with sodium acetate compared to control and decreased with CLA (p <0.05).

By consuming CLA due to the reduction of milk fat, the amount of blood glucose increased, as a result of which the intensity of the negative energy balance decreased, which in turn reduced the damage to the liver cells. Sodium acetate also improves energy levels, possibly due to the supply of acetate for milk fat synthesis. It can be concluded that adding sodium acetate is the best way to have a healthy liver along with increasing milk production and milk fat after birth.

A major change in the diet of ruminants is not sufficiently compatible with the evolution of their gastrointestinal tract, reducing the stability of the rumen ecosystem and ultimately reducing the efficiency of food use. Therefore, under the use of Saccharomyces cerevisiae, it can be a suitable solution to maintain the balance of the microbial population and the optimal activity of microbes, improve the fermentation conditions of the rumen ecosystem and increase the production of ruminants.

In order to investigate the effect of Saccharomyces cerevisiae ode on milk composition, digestibility and blood parameters, dairy cows from 20 Simmental dairy cows with an average milk production of 32 4 4 kg / day were used in a completely randomized design. All 10 cows were randomly assigned to one treatment. Experimental treatments included: 1- control group of base diet without using yeast, 2- base diet + 10 g of Saccharomyces cerevisiae yeast per day per head of cattle, in which yeast was added to the animal feed as road. All diets contained equal concentrations of dry matter, metabolizable energy and crude protein. The cows were milked 3 times a day at 4 am, 12 noon and 7 pm. In the last 7 days of the experiment, in each milking meal, 50 ml of milk was sampled in separate containers and after mixing the milk samples related to the whole meals with each other (considering the share Daily milk production per serving), milk composition was measured. Blood samples were taken from the jugular vein of each cow on the last day of the experiment and 2 hours after morning feeding. To determine the apparent digestibility of feed nutrients, stool and feed samples were taken at the end of the 5 days of the experiment.

The use of Saccharomyces cerevisiae had no significant effect on milk fat, protein and lactose levels. The digestibility of organic matter, crude fat and insoluble fibers in neutral detergent using yeast increased significantly (p<0.05). However, increasing the digestibility of dry matter and crude protein was not significant. Also, the use of Saccharomyces cerevisiae caused a significant reduction in urea nitrogen (p<0.05), but had no significant effect on glucose levels.

According to the test results, the use of Saccharomyces cerevisiae significantly increased the digestibility of organic matter, insoluble fibers in neutral detergent and crude fat, it also improved the production of milk and its compounds. As a result, the use of 10 gr Saccharomyces cerevisiae in the diet of dairy cows is recommended.

Goats are small domestic ruminants that have served humans before other ruminants and is one of the most important sources of protein of animal origin in human nutrition. Milk replacer are widely used in the breeding of young calves and goats. The benefits of using it are increasing productivity and as well as simplifying livestock management. This study was performed to investigate the effect of excess milk replacer on breast milk consumption on production performance, blood biochemical metabolites and fecal parameters including microbial properties of suckling goat kids.

To perform this experiment, 24 Mahabadi suckling goat kids were used in a complete randomized design with three groups of 8 heads for 60 days. The goats were kept with the mother for three days after birth, then were randomly divided into 3 groups of 8 heads. Experimental treatments including group 1- daily consumed only breast milk 2 and 3- daily in addition to breast milk, respectively, consumed 5 and 10% of body weight instead of milk. Growth parameters, including weight, body length, height at the withers, breast and hip circumference, as well as breast milk consumption, starter concentrate consumption, blood parameters, and faecal parameters, including salmonella, Escherichia coli, and lactobacillus, were measured. Data analysis was performed with SAS software.

The results showed that daily weight gain in goat kids that consumed 5% of body weight instead of milk in addition to breast milk was significantly higher than the control group. Live weight and mean daily weight gain of goats with 5% milk replacer consumption on the last day were significantly higher than goats of other treatments. In terms of other growth parameters, no significant difference was observed between goats consuming 5% of alternative and control milk. But they were higher than goats consuming 10% milk. There was a significant difference between the groups in terms of some biochemical blood metabolites. In terms of glucose, albumin and lactate dehydrogenase levels, the first group was significantly higher than the second and third groups. In terms of blood urea nitrogen, the control group was higher and 5% milk replacer consumption group was lower, and the difference between the 10% milk replacer consumption group and the control and 5% milk replacer consumption groups was not significant. The amount of cholesterol in the 10% milk replacer consumption group was lower than the other two groups, the amount of total protein was the highest in the control group and the lowest in the second group. Salmonella was not observed in fecal samples. The rate of Escherichia coli was higher in group kids who consumed 5 and 10% of body weight instead of milk than controls. Lactobacilli were observed only in small numbers in the control group.

The results of this experiment showed that the consumption of milk replacer in addition to breast milk at the rate of 5%  weight of goats can have positive effects on the production performance of suckling kids.

The use of chemical buffers such as sodium bicarbonate, and bacterial additives like Megasphaera elsdenii result in improving the digestibility and fermentation in high concentration diets. Therefore, this research was conducted to compare the effect of acid-consuming bacteria and different chemical buffers for improvements in digestion and fermentation of high concentration diets.

Several chemical buffers were used alone or together with Megasphaera alsdeni bacteria as biological buffers. Two-step digestion methods and specific cultures of anaerobic rumen fungi and bacteria were used in this experiment. The number of 12 treatments includes 1- the control diet (without additives and containing 70% concentrate + 30% fodder or basic diet), 2- the basic diet + 3 ml of Megasphaera alsdeni bacteria (1.5 x 108 CFU/ml), 3 to 12- One percent of the 5 buffers were bentonite-sodium, sodium bicarbonate, magnesium oxide, zeolite, sodium sesquicarbonate alone or together with Megasphaera alsdeni bacteria.

In the two-step digestion test, the digestibility of dry matter was improved in the treatments receiving buffer and bacteria (p<0.05). The digestibility of dry matter, neutral detergent fiber, and acid neutral detergent fiber by rumen fungi was affected by the experimental treatments and was higher in the treatment containing chemical buffer + bacteria than in the control (p<0.05). The use of chemical and biological buffer had a significant effect on the digestibility of nutrients by rumen bacteria and it was more in the treatments containing buffer + bacteria than in the control (p<0.05). The fermentation parameters of the culture medium of bacteria and fungi, including pH and ammonia nitrogen concentration, were significantly affected by the experimental treatments; pH and ammonia nitrogen concentration were higher and lower than the control treatment in all treatments, respectively (p<0.05).

Therefore, according to the results of the present experiment, the use of chemical buffer improved the conditions of digestion and fermentation of high-concentrate diets for fattening lambs, and in many cases, the effect of acid-consuming bacteria was competitive with chemical buffers. On the other hand, the combined use of bacteria and buffer also had synergistic effects.

Protein quality is important for feedlot lambs; protein imbalance may reduce growth rate, increase feeding costs, and emission of gases, particularly methane. In low-producing ruminants, protein requirements can be satisfied mainly with microbial protein, which is produced from nitrogen sources and high fiber. On the other hand, in high-producing ruminants, like feedlot lambs, their high protein requirements for maximum growth rate are not completely satisfied by the microbial protein produced in the rumen. Considering this, it is necessary to provide protein sources that escape rumen degradation. Traditionally, sources of dietary protein are seen as either being of animal or vegetable origin.. In this study, the effect of replacing soybean meal with poultry slaughterhouse waste enriched with  rice bran and urea on performance, rumen and blood parameters of fattening lambs were investigated.

In this experiment, male Kurdish lambs (16 heads with an average weight of 32 ± 2.7 kg and age of 4 to 6 months) were used. At the beginning of the experiment, the lambs were vaccinated and fed antiphrastic drugs. The experimental feed, which included 50 percent of poultry slaughterhouse waste, 47.5 percent rice bran and 2.5 percent urea was substituted for soybean meal at the levels of 33, 66 and 100% and was used in the feeding of fattening lambs. The experiment was carried out as a completely randomized design with four treatments including 1- control diet, 2- 33% mixed feed, 3- 66% mixed feed and 4- 100 mixed feed instead of soybean. The habitation of the lambs to the experimental diet was carried out for 14 days before the start of the fattening period.  The lambs consumed diets containing experimental feed for 84-days   The results of the experiment were analyzed with the  GLM procedure of the SAS statistical program.

The amount of dry matter intake, daily weight gain and feed conversion ratio were not affected by the experimental  treatments. The highest incease in blood glucose concentration was related to lambs receiving the diet containing the highest level of experimental diet (p<0.05). The amount of ammonia nitrogen in the rumen fluid decreased with increasing  of experimental feed level (p<0.05).  The amount of volatile fatty acids in the rumen was  significantly different between experimental treatments (p<0.05). The highest amount of digestibility and crude protein was related to the control group (p<0.05). The diet containing 100 percent of the experimental feed had the highest digestibility for NDF.

In general, the results of this study showed that complete replacement of  soybean meal with experimental feed containing 50% of poultry slaughterhouse waste, 47.5% of rice bran and 2.5% of urea in the diet is possible without any negative effect on fattening performance.

In order to achieve high productivity, goats should be introduced into controlled breeding systems after birth; in this case, goats with a weight of about 30 kilograms are sent to the slaughterhouse due to the high quality of the carcass, more customer-friendliness and has higher nutrients. Also the milk of mother goats is sold, which is very important from the economic aspect for livestock breeders and increases productivity. Therefore, early weaning and using starters with high energy levels can be a practical solution in reaching the target weight of kids as soon as possible.

This experiment was performed to investigate the effect of feeding with different levels of Cannula as a fat supplement in the initial diet on the function and rumen and blood metabolites of early weaning in Mahabadi goats. The number of 20 males and females Mahabadi goats were fed with mother’s milk for 4 weeks after birth. Further, the goats were randomly divided into 4 groups of 5 heads and after the acclimation period for 2 weeks, they were fed experimental diets for tow month in a completely randomized design. Experimental diets included starter feed with concentrate to forage ratio of 10:90 and had different amounts of Cannula (3, 4.5 and 6 percent) as fat source.

The results showed that the effect of treatments on dry matter intake and weight gain of goats was significant (p<0.05). The highest amount of feed intake and weight gain was observed in the treatment of 3% of Cannula. Digestibility of dry matter, organic matter, ether extract, crude protein as well as ruminal pH was not affected by experimental treatments; However, the digestibility of neutral detergent fiber in 3% Cannula treatment was more than 4.5 and 6% (p<0.05). Blood glucose and cholesterol levels showed a significant decrease in all treatments compared to the control group (p<0.05).

In general, it can be concluded that early weaning of goats by feeding with starter ration and Cannula can improve feed intake and weight gain and consequently cause the desired weight to be reached earlier; therefore, the use of 3% Cannula with 87% starter concentrate in feeding of Mahabadi pre-weaned goats is recommended.

Because enzymes enhance the digestibility of feeds by increasing the availability of minerals and the digestibility of protein and amino acids, the utilization of enzymes is known as an effective method for increasing profitability in the poultry industry. In addition, certain enzymes are able to hydrolyze non-starch carbohydrates, resulting in an increase in feed energy utilization and the release of additional phosphorus through the degradation of phytic acid. The purpose of this study was to investigate the effects of a blended supplement consisting of probiotics, prebiotics, and enzymes (containing protease, phytase, lipase, and different carbohydrase) on productive performance, blood metabolites, hormone profile, and antioxidant status of laying hens.

For an 8-week trial, 120 laying hens (52 weeks of age) were used in a completely randomized design with three treatments, eight replications, and five hens per replication. The experimental treatments included the control treatment (no additives) and treatments with complex enzyme supplements at 250 and 500 mg per kg of feed. Egg production, egg weight and feed intake were recorded daily. Egg quality traits and blood biochemical parameters were evaluated at the end of experiment.

The results showed that the treatment receiving 500 mg/kg of blended supplement had a greater egg production, greater egg mass, and while feed conversion ratio compared with the non-supplemented treatment (control treatment). The percentage of abnormal eggs was lower in all of the treatments that received the blended supplement compared to the control. A linear increase was observed in the blood levels of cholesterol, albumin, triiodothyronine, total antioxidant capacity, and superoxide dismutase activity after the inclusion of the supplement in the diet. In contrast, the concentrations of glucose, phosphorus, uric acid, alkaline phosphatase, TSH and T4 hormones, malondialdehyde, and nitric oxide, as well as the activity of blood glutathione peroxidase and catalase enzymes, were not affected by the experimental treatments (p>0.05).

In conclusion, including the blended supplement in the diet of laying hens, particularly at the level of 500 mg/kg, during the second phase of the laying cycle has a positive effect on both production performance and health status, which may be attributed to an increase in antioxidant status and a decrease in stress levels.

Phytoestrogens are herbal estrogens with estrogen-like functions and structures. The estrogen hormone has an important role in the process of the synthesis of egg white proteins in the avian oviduct. Vitex agnus-castus (VAC) is a native plant of the middle Asian, southern European, and Mediterranean countries. This plant has numerous uses in traditional medicine and is traditionally used to treat many diseases in women. Previous studies have shown that VAC contains high levels of phytoestrogens. VAC consists of compounds such as vitexin, apigenin, and pendoltin, which are the most active phytoestrogen in VAC fruits. No study has been published so far on the effect of VAC on oviduct markers gene expression (ovalbumin (OVAL) and ovomucoid (OVM)). Hence, this study was performed to evaluate the effect of VAC fruits on gene expression for two oviduct markers OVAL and OVM of laying hens.

A total of 90 leghorns (Hy-Line, W-36) laying hens on the second cycle of production (at 72 to 80 weeks old) were used in a completely randomized design with three treatments, five replicates and six hens per replivate. The treatments were various levels of VAC fruit powder including zero, 1, and 2% levels of VAC fruit powder per kg of diet. After extraction of total RNA, RNA quality was evaluated using Nanodrop and agarose gel electrophoresis and cDNA was synthesized using a Sinaclone kit. Eventually, gene expression was measured by the real-time qPCR method. In this method, 𝜷-actin gene was used as a reference gene to normalize the gene expression data. To confirm the specificity of each primer, its melting curves were examined.

Electrophoresis of the PCR products showed the 60, 133, and 150-bp fragments for OVAL, OVM, and Beta-actin, respectively. Melting peaks analysis on the PCR products for all primers confirmed minimal primer-dimers and primer specificity. The results of the real-time qPCR method indicated that supplementation of VAC fruits powder at levels 1 and 2 to the diet of laying hens has no effect on the expression of OVAL and OVM genes of laying hens in the second production cycle.

Therefore, Adding VAC fruit powder to the diet of laying hens is not expected to increase egg production in laying hens. Therefore, VAC supplementation is not recommended to the diet of laying hens.

Crossbreeding as the fastest approach to take advantage of difference between breeds, can be an effective method to improve the efficiency of meat production in sheep. The aim of the present study is to compare Balochi lambs with the crossbred obtained from Baluchi ewes with Kurdi and Karakul rams.

In order to investigate the effect of crossbreeding on the weight performance of lambs up to weaning and the fattening period and carcass composition, three genetic groups including pure Baluchi (BB) lambs, Karakul × Baluchi (GB) and Kurdi × Baluchi (KB) crosses were used. The ewes were mated in groups of 50 and each group with 2 rams. The number of 27 purebred and crossbred male lambs were used in the form of three treatments with three replications and three lambs per replication. Data were analyzed using GLM procedure of SAS software.

The results showed that lambs from Karakul rams had the highest birth weight and lambs from Baluchi rams had the lowest birth weight (4.80 and 3.95 kg, respectively). Lambs from karakul rams had higher daily gain (260g /day) before weaning than other lambs (p<0.05).  The highest and lowest dry matter intake were in the GB group (1250g /day) and the BB group (950 g / day), respectively. The highest daily gain in GB group and the lowest in BB group were 169.2 and 93.8 g / day, respectively (p <0.05). The genetically groups had significant effect on cold and hot carcass weights (p<0.05). The effect of crossbreeding on fat thickness, fat-tail, and shank was significant (p<0.05).

Due to the suitable reproductive performance in using Karakul ram as a paternal breeding base and optimal performance in growth rate, feed consumption, conversion ratio in the pre-weaning and post-weaning periods as well as carcass characteristics including hot and cold carcass weight and less tail compared to other crossbreds used in this study, it is probably more appropriate to use Karakul rams to produce crossbred lambs.

Although, unlike many livestock, no intense artificial selection has been made on dromedary camels, traces of natural selection along with selection by the human can still be found as selection signatures in the camel genome. Due to the development of new technologies as well as bioinformatics tools, the detection of these genomic regions can be done with high accuracy. This study aimed to identify the selection signatures on the X chromosome in Iranian dromedary camels using whole genome sequencing data.

For the present study, the genomic data from six Iranian dromedary camels were used as the target population and also eight samples of dromedary camels from the Arabian Peninsula as the reference population. Signatures of selection were identified using two methods, including Fst and XP-EHH. A window size of 50kb and a step size of 25kb were used for this analysis, and genomic windows with scores higher than the 99th percentile of ZFst and XP-EHH distribution were considered as putative selection signatures. BEDtools program was used to extract genes located in these regions. Gene ontology analysis was performed on mentioned genes using g:profiler program.

Based on the results, 13 and 27 genes identified using Fst and XP-EHH approaches as positively selected genes on the X chromosome in Iranian dromedary camels, respectively. The results of gene ontology (GO) analysis showed that terms related to fat metabolism have a significant contribution among the significant GO terms. Among the important identified genes, the genes of DGAT2L6 and AWAT2 may involve in the camel's resistance to high levels of ultraviolet radiation in desert conditions. Also, the NSDHL gene, which is involved in cholesterol biosynthesis, play a role in male fertility. The only significant KEGG pathway in this study was related to vitamin A metabolism.

It seems that the positive selection of genes related to fat metabolism, behavior and resistance to ultraviolet radiation in Iranian dromedary camels has been for interaction with humans and harsh desert conditions. Due to the lack of breeding programs on camels, it seems that knowing the genomic features of this species can be considered as a prerequisite for designing breeding strategies.

Fertility is one of the most important economic traits in dairy cattle breeding which, in addition to negative effects on functional traits such as milk production, reduces the profitability of the dairy cattle breeding industry. Therefore, the aim of this study was to Meta-analyze traits related to fertility in dairy cows and determine an appropriate strategy to control and improve fertility in dairy cows.

For this purpose, by searching in databases, 38 articles related to fertility in different herds of dairy cows were collected and different parameters including additive genetic and residual variance components, heritability, reproducibility, descriptive characteristics of traits including mean, minimum, maximum, coefficient variation, standard deviation as well as genetic correlations between traits that were present in at least three reports were extracted as a new variable and statistically analyzed. The studied traits included age at first service, age at first calving, calving interval, open days, number of services, conception length, the first service leading to conception and non-return rate at 56 days. Data analysis was performed with SAS software version 9.2 and Comprehensive Meta-analysis. Finally, the articles were grouped into four regions of Asia, Africa, America and Europe and different parameters including mean, heritability and reproducibility of different fertility traits were analyzed by SAS software GLM procedure and comparison of mean groups by Turkey’s test at the level 5% probability was done.

Mean of open days, age at first calving, age at first service, calving interval, conception length, first service leading to conception rate, no-conception rate in 56 days and numbers of services for each conception traits were 139.2, 888.3, ​​501.6, 411.8, 278.8 days, 62.8, 21% and 2.1, respectively. Also, the heritability of the mentioned traits was estimated to be 0.06, 0.2, 0.3, 0.06, 0.1, 0.1, 0.07 and 0.08, respectively. The reproducibility of traits were open days, calving interval, first service leading to conception, conception length and number of services per conception were 0.1, 0.1, 0.07, 0.1 and 0.06, respectively. There was a moderate and sometimes high positive and negative genetic correlation between most of the fertility-related traits. The results of comparison of estimates in the four continents of Asia, Africa, Europe and the Americas were not significant in all fertility-related traits.

Therefore, all the mentioned estimates, which in most cases are reliable and close to each other, indicate a low degree of heritability and repeatability of the mentioned traits, and the use of conventional breeding methods cannot determine high genetic value with good accuracy and it is recommended to improve the management of dairy cows and control environmental factors and the use of breeding programs as well as genomic evaluation of dairy cow.

The BRCA1 gene, which is called “gate keeper” It plays an important role in the process of repairing DNA damage, regulating the cell cycle, regulating the transcription process, maintaining chromosome stability, and other important pathways for the maintenance of genome stability. The current research was conducted with the aim of bioinformatic analysis and comparison the genetic diversity and phylogenetic structure of the BRCA1 gene of different breeds of domestic and wild sheep from 49 breeds in 6 geographical regions: Western Asia, Europe, China, North Africa, South Africa and wild (Iran) using the NCBI genome databas.

The desired sequences were aligned using MEGA11 software and a phylogenetic tree was drawn by Neighbor-Joining method. Also, the number of mutations, nucleotide diversity, haploid diversity, the number of positions in which similar or non-similar substitutions occurred, the percentage of gene differentiation, gene conversion were also analyzed using Dnaspv5 software.

The analyzes related to the comparison of breeds in 6 geographical regions showed 112 polymorphisms, which led to the creation of 19 different haplotypes with a haplotype diversity of 0.035. Nucleotide diversity and average nucleotide differences (k) among breeds were estimated as 0.205 and 0.052, respectively. The genetic differentiation between the Chinese sheep population and the wild sheep population was the lowest. The average genetic distance between all geographical regions was calculated to be 0.29. The average nucleotide ratio (A+T):(G+C) was equal to 38:62%, which indicates the predominance of cytosine and guanine bases. The amount of conserved sequence (c) in this research was 0.313 on average, which indicates the high polymorphism of this gene and the creation of new proteins as well as new functions to adapt to different homeostasis conditions. The effective number of codons (ENC) in this research was calculated to be 56.41. The value of D in the Tajima neutrality test was 0.478, which indicates that the selection pressure is balanced.

The high genetic diversity in the wild population, the reasons for which are the presence of forest and open environments, prevention of genetic drift and reduction of inbreeding, which affects muscle strength, eating habits, aggressive behaviors, defense responses, sensory perception of confrontation with environmental conditions and stress that related to BRCA1 gene expression in these populations.

Dominant genetic effects may have an important contribution to the total genetic diversity of quantitative and complex traits. However, genome-wide marker research to study genomic prediction (GP) and genetic mechanisms of complex traits generally ignore dominant genetic effects. The increasing availability of genomic datasets and the potential benefits of non-additive genetic effects have recently attracted much attention to  combining these effects into genomic prediction models.

A genome with 3 chromosomes of 100 cM each, with 200 QTL and 1000 biallelic markers on each chromosome were simulated.. Then the information related to records of pedigree, year of birth, weaning weight, offspring sex, percentage of twinning, carcass weight, carcass quality, age of first calving, wool density and other economic traits of Moghani sheep that were obtained through Jafarabad Moghani Breeding Center (during 1382 to 1393) formed the phenotypic matrix of the model. Additive and dominance genetic effects and accuracy of genomic prediction of 7 traits, including growth, carcass quality, wool and fertility were adopted through two linear models: (1) ) an additive effect model (MAG) and (2) a model that includes additive and dominance genetic effects (MADG). In addition, the 5-layer cross-validation method was used with R package “HIBLUP”to evaluate the GP capability in two different models.

The results of estimating variance components for each trait show that carcass weight (0.617) and lambing percentage per ewe (0.578), a large part of the phenotypic variation is explained by dominance genetic effects. Cross-validation results showed that the MADG model, including additive and dominance genetic effects, has a clear advantage over the MAG model, which includes only additive genetic effects. that’s means, the model that includes dominant genetic effects improves the accuracy of genomic prediction.

The better performance (prediction accuracy) of the MADG model for some traits compared to the MAG model shows that dominance effects should be included in animal genetic evaluation models to improve the accuracy of predicting future phenotypes. MADG model can also be a useful tool for culling decision  in farms, and the use of the entire genetic potential of progeny in mating programs may improve progeny performance.