فصلنامه پژوهشهای تولیدات دامی
پیاپی 18 (زمستان 1396)

This experiment was conducted to evaluate the effects of dietary levels of crude protein, methionine and betaine on performance and carcass characteristics of broiler chickens. A total of 640 one-day-old broiler chicks from Ross 308 strain were used. Each pen (1.5 ×1.5m) was assumed as experimental unit and was included 20 male and female chicks. The experiment was conducted based on completely randomized design as a 2×2×2 factorial arrangement. The chicks were reared on the basis of regular brooding procedures until 7 days of age and then were fed with diets containing 2 levels of crude protein (high and medium), 2 levels of methionine (high and medium) and 2 levels of betaine (0 and 0.08%) from 7 to 42 days of age. All experimental diets were prepared isocaloric. Average daily feed intake, average daily weight gain and feed conversion ratio was measured weekly. At day 42 of age, one male bird from each pen was selected and slaughtered for carcass analysis. Results of this experiment showed that none of treatments had a significant effect on feed intake in 7 to 42 days of age (P> 0.05). Betaine fed groups showed more daily feed consumption in compare to other groups but this effect was only significant during 14-21 days of age (P

The purpose of this research was to evaluate the effects of different levels of dietary protected butyric acid (PBA) on growth performance, blood metabolites, calcium and phosphorous of tibia in broilers. Two hundred and seventy day old Ross 308 male broilers divided in 9 treatments and 3 replicates (10 chicks per replicates), in a completely randomized design. Experimental treatments included: (1) control (without additives), (2) 0.1% Bacitracin (positive control), (3) 0.2% PBA in starter period, (4) 0.2% PBA in starter and grower periods, (5) 0.2% PBA in starter, grower and finisher periods, (6) 0.3% PBA in starter period, (7) 0.3% PBA in starter and grower periods, (8) 0.3% PBA in starter, grower and finisher periods and (9) 0.5, 0.4 and 0.3% PBA in starter, grower and finisher periods, respectively. Results indicated that the highest daily weight gain in starter period was related to birds fed 0.2% PBA, having significant difference with birds fed control, 0.3 and 0.5% PBA (p≤0.05). Use of PBA had no effect on body weight and daily weight gain in grower, finisher and total periods. PBA levels and Bacitracin did not effect on feed intake and feed conversion ratio of broilers. PBA did not have significant effect on blood metabolites (except blood plasma calcium) and calcium and phosphorous percentage of tibia at 42 days of age. Based on the taken results, it seems that use of 0.2% PBA as a replacing additive of antibiotic in broiler' diet is useful, especially in starter period.

The aim of this study was to compare the levels of chlorella vulgaris microalgae extract with additives on performance, carcass characteristics and blood biochemical metabolites in heat-stressed broilers. This experiment has been done using 280 one day-old Ross 308 broiler chicks for 6 weeks. This experiment has been done in completely randomized design with 7 treatments and 4 replicates. Experimental treatments were including: 1- control; 2- diet containing 0.2 g/Kg chlorella extract; 3- diet containing 0.4 g/Kg chlorella extract; 4- diet containing 100 mg/Kg vitamin E; 5- diet containing prebiotic; 6- diet containing probiotic; 7- diet containing antibiotic. Heat stress program applied from 25-42 d.Treatment 2 caused an increase of feed intake and weight gain in comparison to other treatments (P

Effect of different levels of date waste were studied on performance and immune responses of 240 Ross 308 broiler chicks in a completely randomized design with 5 treatments and 4 replicates and 12 birds in each replicate. The whole date waste were analyzed for chemical compositions and gradual levels of 0 (control), 5, 10, 15 and 20 percent of that were included into the diets which fed broilers for 42 days. Growth performance was recorded, weekly. Humoral immune response was evaluated by intramuscular injection of 0.1 ml sheep red blood cell (SRBC) 25 percent suspension on days 8 and 22 of age and serum antibody levels produced in response to SRBC was measured on days 21, 28, 35 and 42. Cellular immune response was assessed by intradermal injection of phytohemaglutinin on day 16. Using date waste in diet had no significant effect on daily feed intake. Daily weight gain was linearly decreased by increasing the levels of dates waste in diet (P

This experiment was conducted to study the effect of type of feed processing and type of phytase enzyme on growth performance, calcium, phosphorus tibia and toe ash ,fecal and ileal digestibility of phosphorus in broiler chickens. A total of 420 broiler chicks (Ross 308) were used in a completely random design in the a 2×3 factorial arrangement using two processing methods (pellet and mash) and three groups of enzyme (negative control, natuphos (Aspergillus niger) and Meriphase (E.coli). The experiment lasted up to 42 days of age. Levels of enzymes used in the experiment were 500FTU kg-1. The results showed that pelleting diet significantly increase the average daily feed intake, body weight and significantly improved feed conversion ratio (P

This experiment was conducted to compare the qualitative feed restriction and meal feeding on the performance, carcass yield and Ascites syndrome in Ross-308 broiler chickens. One hundred eighty day-old chicks raised for 42-d in a completely randomized design with five treatments, three replicates and 12 chicks per each pen. Experimental treatments included: 1) ad-libitum intake, 2) ad-libitun intake plus levothyroxin (1.6 mg/kg of diet), 3) eight-hours feed restriction per day from 7 to 14 days, 4) Ninety-five percent of straw requirements, 5) Ninety percent of straw requirements. In order to induce Ascites, 1.6 mg /kg of levothyroxine hormone were added to all treatments except for the control treatment from the day 25 of the experiment. The results showed that at the end of the experiment, body weight of the chickens that were received levothyroxine and 8 hours of feed restriction were significantly lower than control treatment (P

The present study was conducted to evaluate the efficacy of organic acids combination on performance, blood biochemical parameters, intestinal morphology and internal egg quality parameters of layer Japanese quails in completely randomized design manner using 225 layer quails in 3 treatments, 5 replicates and 15 quails in each replicate, reared for two periods of 3 weeks each (37-39 and 40-42 weeks). Treatments were: 1) control; 2) basal diet with 0.04% AGP (bacitracin dimethyl salicylate) and 3) basal diet with 0.01% of organic acids combination. Results showed that feed consumption, egg production, egg weight and egg shell percentage were increased significantly compared to the control group by incorporating organic acids combination into the diet. Also significant increase the intestinal villus height, number of goblet cells and intestinal crypt depth were observed in the organic acids supplemented group. The lowest concentration of calcium, high-density lipoprotein, serum levels of alkaline phosphatase, feed conversion ratio and Haugh unit scores were found in organic acids fed quails. Glucose, total protein, phosphorus and serum aspartate aminotransferase values were not affected significantly by the experimental groups. Based on the results of this study, application of organic acids combination as a viable alternative to antibiotic growth promoters can be recommended in layer Japanese quails egg.

One of the problems of the poultry industry is a lack of flocks in broiler farms Although it in the factories of hatchery broiler chickens and turkey, often Sexing chickens to are selling commercial growers Because sex differences in growth rate and feed efficiency, separating males and females to the necessary recurrence needs of uniform and Specified market in terms of production carcasses. The current study was conducted to evaluate effect of in ovo injection of Pine pollen extract on growth and sex differentiation of broiler chicks. A total of 500 Ross (W-308) egg completely randomized with five treatments were assigned to 4 replicate of 25 egg in each pen. Treatments included: 1-.Non-injected control 2-.Shem control (Solvent injection) 3- injection 50 ppm of Pine pollen extract 4-injection 100 ppm of Pine pollen extract 5- injection 150 ppm of Pine pollen extract. The economic characteristics, hatching percent and the sex differentiation and the relative expression of IGF-I and IGF-II were evaluated. The results of this study showed that Pine pollen extract no significant effect on economic characteristics, hatching percent and the sex differentiation and the relative expression of IGF-II but the relative expression of IGF-I was significantly decreased in dose 51 and 100 ppm.

During the semen cryopreservation, various biochemical and anatomical compartments in the sperm cells may be altered. Therefore, the most important part of sperm-freezing protocols is use of cryoprotectant agents in freezing. The aim of this study was to determine the effect of different dosage of egg yolk (15, 20 and 25 %) as natural a cryoprotectant plus different dosage of sodium dodecyl sulphate (0, 0.05 and 0.1 %) as surfactant on quality cryopreserved Holstein bull sperm. In this study Semen was collected from three mature Holstein bulls twice a week using an artificial vagina and pooled ejaculates equally in order to eliminate the individual effects. After cooling, filling and sealing of the samples, they were frozen with nitrogen vapor and immersed in liquid. Results showed that semen extender with base of different dosage of egg yolk supplemented with various doses of SDS (0.05 and 0.1 %) increased (p

Heat stress has adverse effects on livestock production, hence reducing benefits of them. With the viewpoint of reducing heat production within cells,an experiment was conducted to investigate the effects of different sources of fat on mitochondrial energetics of broilers in chronic heat-stress condition. The consumed fat included: a)tallow; as a source of long-chain fatty acids, b)coconut oil; as a source of short and medium-length-chain fatty acids, c)olive oil; as a source of monounsaturated fatty acid (MUFA)and d. soy oil; as a source of polyunsaturated fatty acid (PUFA). Broilers were under chronic heat stress (36 oc) from 32 to 42 d of the experiment. Broilers fed with tallow or coconut oil showed higher mitochondrial dehydrogenases activity, membrane potential and ROS production (p˂0.01) and lower glutathione concentration (p˂0.01) than those fed with olive oil or soy oil. The results seggest that in heat stress conditions using saturated fat sources especially those with long-chain fatty acids could help in reducing heat production inbroilers.

The aim of present experiment was to measure endogenous urinary purine derivatives using feed restriction method, as well as to determine the effect of 4 levels feeding on microbial protein synthesis. The present experiments was conducted by four camels about 326 Kg body weight. The camels were fed by different level of Atriplex leucoclada (AL), including maintenance, 1.25, 1.5 times of maintenance, and ad libitum in Latin square design, and their microbial protein synthesis measure with urinary purine derivatives. In the first experiment, the amount of purine derivatives at fifth day of starvation period, as index for endogenous excretion of urinary purine derivatives determined equal to 14.0 mmol/day. The allantoin was the main urinary purine derivatives excretion in all three starvation period. Urinary excretion of the allantoin decreased with decreasing the level of feeding intake (P

The current study was evaluated the increased dietary protein level supplied either by soybean meal or meat meal sources (SBM vs. MM) in growing Holstein male calves on performance, blood metabolites, liver enzymes and insulin. 36 growing Holstein male calves averaging 167.7 kg body weight were allocated in a competently randomized design (12 animals/each) in 3 treatments; 1) basal protein level (crude protein=13.8%; CON), 2) SBM source (14.9%), 3) MM source (14.9%). The study lasted 9 weeks. The results show that intake and gain of calves did not differ among treatments. Regardless of protein sources, elevated crude protein level caused to slight increase in feed efficiency (P=0.09). Among the blood metabolites only glucose was tended to be increased (P=0.07). Liver enzyme concentrations (alanine aminotransferase and aspartate aminotransferase) were not differed among treatments; however blood insulin concentration was greatest in MM treatment (P=0.04). In conclusion despite greater CP level supplied with SBM is not recommendable but improved glucose concentration and increased insulin concentration with MM may affect growth rate of growing calves.

The aim of present study was to evaluation of Hach method for determining of crude protein contents of some animal feeds. Twenty one samples of animal feeds and digesta, including a variety of forages, concentrate feeds and mixtures and digesta ruminal samples and 0.025, 0.05, 0.075, 0.1, 0.175 and 0.2 mg ammonium chloride were chosen and their nitrogen and protein contents were measured using Kjeldahl, as the reference method and the Hach Methods and compared with each other. There was no significant difference between the methods in terms of crude protein content estimation of different feed samples and different amounts of ammonium chloride. The regression between the crude protein contents measured by the two methods was linear and showed a significant correlation (r=0.99). Modifing the digestion method of the original Hach method accelerate the method and it makes possible to analysis more samples without any negative effects on the obtained results. According with the reslt of this experiment the protein content of some analyzing samples in animal nutrition laboratories can be accurately measured through the Hach method.

According to global, regional and economic importance of Jabal Barez Red goat from the cashmir production aspect and role of Rheb gene on growth, cell cycle and cancer, expression of this gene was studied in Jabal Barez Red goat for the first time. As one member of the Ras super family, Rheb is an upstream regulator of mTOR signaling pathway, which regulates the process of cell-growth, proliferation and differentiation. In order to study expression levels of Rheb in various tissues including brain(medulla), brain(cortex), heart, kidney(cortex), kidney (medulla), testis, lung, liver and spleen,the cDNA of Rheb gene was amplified by Real-Time PCR and analysed by Pfaffl method. SAS software was used to analyze the resulted data of the Pfaffl method. Results showed that the Rheb gene was expressed in the all tested tissues and the highest level of expression was observed in spleen and the lowest level in lung. Hence, it can be suggested that Rheb gene express in all tissues that require the physiological effects of this gene to be considered in different tissues and different animals.

Lipopolysaccharide is a component of outer membrane of gram-negative bacteria involved in the pathogenic process leading to mastitis and metritis in dairy cattle. Additionally, LPS could be caused endometrium inflammation and implantation failure in many animal species. Based on economic importance of these diseases in dairy cattle industry, analysis of differential gene expression (DGE) and also detection of related pathways in LPS challenge using transcriptome analysis is essential in understanding the mechanism of process. In the present study, after separation of endometrial epithelial cells, and expose them with different doses of LPS (0, 2 and 8 mg/ml), total RNA was extracted and was used for transcriptome libraries preparation. In general, 12 samples (four samples per cow) were sequenced by high throughput technology from three Swedish Red breed cows. The DGE and also biological pathways were identified. The results of present study showed that 2035 genes differentially were expressed between control and treated groups which 752 genes involved in cell proliferation and apoptosis pathway. Additionally, the results of counted epithelial cells have shown that LPS could be significantly increased cell proliferation. Biological pathway analysis showed that some signaling pathways related to immune system such as Toll-like receptor, T cell receptor, MAPK signaling pathway, chemokine signaling pathways, endometrial cancer pathway and also apoptosis and cell proliferation signaling pathways involved in this challenge. According to our knowledge, this study is the first research that has been done in bovine endometrial epithelial cells which can increase our understanding related to the mechanisms of inflammations caused by uterine infections in dairy cattle.

The objective of this study was to select the best model among five non-linear growth functions, i.e., Brody, Gompertz, Logistic, Von Bertalanffy and Negative exponential for describing the growth curve in Markhoz goat. The data included 5557 body weight records of goats from birth to yearling which were collected during 2006 to 2013 at Sanandaj Research Station. Growth curve parameters (A, B, K) were estimated by the NLIN procedure of SAS program and in order to compare different models for selecting the best model, statistics of coefficient of determination (R2adj), Akaike´s Information Criterion (AIC), Bayesian Information Criterion (BIC), Root Mean Squares Error (RMSE) and Durbin-Watson were calculated. For all animals, Logistic model was the best model as provided the greatest R2adj and the lowest values of RMSE, AIC and BIC than other models and this model could indicate the best prediction of growth in Markhoz goat. The best selected models for predicting growth of males and females were Brody and Gompertz models, respectively; and Logistic model was selected as the best model for both singles and twins. The negative exponential model provided the worst fit of growth curve for all animals, males, females, singles and twins. Logistic model can provide the best prediction of growth pattern of Markhoz goat over a definite time period.

In this research, investigation of genetic, phenotypic and environmental trends of biometric traits in Makuie sheep was performed using collected data from 1989 to 2012 at Makouei sheep breeding station. Estimation of trends was performed by multivariate animal model using the DFREML software. Genetic, phenotypic and environmental trends were estimated by regression of breeding values average, phenotypic values average and average of difference between breeding values with phenotypic values on birth year, respectively. Results showed that heritability estimates for biometric traits including height at withers, height at rump, body length, heart girth and thigh circumference were 0.23±0.05, 0.25±0.05, 0.19±0.04, 0.28±0.05 and 0.06±0.04, respectively; and the highest genetic and phenotypic correlations were between height at withers and height at rump traits (0.98 and 0.93, respectively). Genetic trends of mentioned traits were 0.25±0.07, 0.26±0.07, 0.59±0.05, 0.22±0.09 and 0.23±0.03 cm; phenotypic trends were 0.08±0.08, 0.07±0.05, 0.39±0.06, -0.23±0.16 and 0.08±0.05 cm and environmental trends were -0.16±0.06, -0.15±0.06, -0.20±0.06, -0.45±0.15 and -0.16±0.04 cm, respectively. Total genetic improvement after 24 years was low and the highest improvement was observed in body length and chest girth traits therefore, it can be concluded that despite the positive genetic trend, selection in this herd were not based on breeding value and regular plan.

Mastitis is one of the most common diseases in dairy cattle, which has imposed therapy heavy costs to farmers through significant reduction in total milk production. Identification of nucleotide polymorphism of two candidate immunity response genes and its effects on SCS as a mastitis incidence indicator was carried out in this research. The genes were exons 1 and 2 of TLR2 and 3 and 4 of TNFα. For this purpose, a hundred Holstein lactating cows were selected based on their breeding values for milk production, fat and somatic cell scores. Then cows based on their residual values for somatic cell scores were divided into two resistant and susceptible groups and 5 ml blood samples were collected from each animal. Selective genotyping of two target groups of susceptible and resistant animals to mastitis was done using PCR-RFLP approach. The association between genetic polymorphisms with corrected records of somatic cell scores (residual values for somatic cell score) were analyzed using the Generalized Linear Model (GLM) procedure of SAS statistical package (version 9.2) followed by means comparison with Tukey-Kramer test. There was a significant direct relationship between TLR2 and TNFα gene polymorphisms and somatic cell score residual values (P

Prolactin is secreted from the anterior pituitary gland and plays an important role in the mammary gland development, differentiation and lactation. The aim of current study was to evaluate prolactin receptor gene polymorphisms in the Shal breed and Shal×Romanov crossbreeds. For this purpose, after blood sampling of animals and extraction of DNA using phenol chloroform method, two fragments of 176 and 215 base pairs from intron 1 of prolactin receptor gene were amplified using PCR reaction. Then PCR products were analysed by acrylamide gel electrophoresis and silver staining. Results showed that AB and AC genotypes were identified in 176 base pairs fragment of prolactin receptor gene (PRLP1) in Shal breed. The frequencies of these genotypes were 0.92 and 0.08, respectively; and the frequencies of A, B and C alleles were 0.5, 0.46 and 0.04, respectively. Also, in the position of PRLR1 of this gene in Shal×Romanov crossbreeds, the frequencies of AB and AC genotypes were 0.94 and 0.06, respectively; and the frequencies of A, B and C alleles were 0.50, 0.46 and 0.04, respectively. A polymorphism study in the 215 bp fragment of the prolactin receptor gene (PRLR2) in the Shal and Shal×Romanov crossbreeds showed only AA genotype. Results of this study showed that PRLP1 position in Shal breed and Shal×Romanov crossbreeds was polymorphic, however the PRLP2 position in the studied samples was monomorphic.

In most genomic prediction studies only additive effects will be used in models for estimating genomic breeding values (GEBV). However, dominance genetic effects are an important source of variation for complex traits, considering them into account may improve the accuracy of GEBV. In the present study, performed applying simulated data, the effect of different heritability values (0.1, 0.3 and 0.5) and different values for the proportion of dominance variance to phenotypic variance (0, 0.05 and 0.15) on genomic selection accuracy in parametric (LASSO, A and B Bayes) and non-parametric (RKHS) statistical methods were studied. Correlations between the true and genomic breeding values, as a measure for the accuracy of genomic predictions under different scenarios were calculated using R software. The results of the present study revealed that, under all statistical methods as heritability values increased, the accuracy of genomic predictability increased. Also, as the value of dominance variance to phenotype variance increased genomic accuracy slant was slow under parametric methods but in the non-parametric method accuracy continued to increase. Under non parametric method the average mean square error was more reduced as the ratio of dominance variance to phenotype variance increased. Therefore, it may be concluded that under non- parametric method as the ratio of dominance variance to phenotype variance increased the accuracy of genomic predictions would be more increased than that of under parametric methods.

This research was done to estimate of inbreeding coefficient and its effect on some of productive and reproductive traits in Moghan agro-industrial company Holstein cows with using of 17966 Holstein cows pedigree data from 2007 to 2016. For preparing and editing of data, estimate of inbreeding coefficient and traits regression content from inbreeding Fox pro, Excel, CFC and Wombat softwares were used respectively. 32.12 percent of total animals were inbreed. Inbreeding coefficient average for total population and inbreed animals in this study was calculated 0.56% and 1.85% respectively. The lowest and highest inbreeding amount in this herd was observed 0.78% and 37.5% respectively. Inbreeding depression for 1% increasing of inbreeding for milk production, number of days in milk, open days and age at first calving were estimated -15.14 kg, -1.60, 0.09 and 0.40 day respectively, except for age at first calving was not statistically significant (P>0.01). The results of this research showed, in compare with the other similar population, average of inbreeding coefficient was lower in this herd that could be related to factors like preventing of very close inbreeding and tending to controlled mating.

The aim of this study was to compare different methods of Bayesian (parameteric) approaches for predicting genomic breeding values of traits with different genetic architecture in different distribution of gene effects, number of quantitative traits loci, heritability and the number of reference population using simulated data. A genome contained 3 chromosomes, with the length of 100 cM and 1000 evenly spaced single nucleotide polymorphisms (SNP) on each chromosome was simulated. For hypotheses simulation attributes, different distribution of gene effects (uniform, normal and gamma), 3 levels of QTL (50, 200 and 400), 2 levels of heritability (0.16 and 0.5) and 2 levels of the reference population (1000 and 2000) was considered. In order to predict breeding values of individuals in the population of reference and verification, 5 Bayesian methods including Bayes Ridge regression (BRR), A, LASSO (L), Cπ and B were used. As the distance between reference population and selection candidates increased, due to disruption of linkage phase, the accuracy of genomic breeding values in all methods decreased. As heritability increased from 0.16 to 0.5, all methods showed an increase of about 0.2 in accuracy of genomic breeding values. When the number of reference population had increased from 1000 to 2000, all methods showed increased accuracy by nearly 0.18. When the distribution of gene effects was gamma, the Bayes A method showed a clear preference along with both levels of heritability compared with other methods. When the distribution of gene effects was uniform, all methods showed similar accuracy. For high heritability traits, the accuracy of prediction reduced as the number of QTL increased from 50 to 200. Conversly, in low heritability traits, there was no visible influence in accuracy of genomic breeding values.

For genetic analyses of growth traits of Kermani sheep including body weight at birth, three, six, nine and twelvemonths of age, 10, 459 body weight records measuredon 3132 animals originated from 78 sires and 1163 dams were used. The data were collected at Kermani sheep breeding station during 1988 to 2010. The data were analyzed using a multivariate animal model. In the model, animal age, sex, type of birth, year and season of birth were fitted as fixed effects. Maternal genetic effects as well as the direct additive genetic effects were fitted as the random effects. Heritability estimates of the body weight measured at birth, 3, 6, 9 and 12 months of ages were 0.14, 0.33, 0.34, 0.12, and 0.16, respectively. The genetic correlations between the growth traits were in a range of 0.78 to 0.98. These results show that the growth traits can be improved genetically. In the station, the genetic trends of the traits investigated were generally erratic and the genetic progress was low which were mostly due to the lack of an efficient breeding program. The genetic progress can be achieved if the animals are genetically evaluated based on their individual performance records and pedigree information.

One of the effective and important factors in suitable using from inputs in firms is production scale of firm. According to effective role of milk production scale in dairy farm cost, determination of scale with minimum cost is necessary. In this study, optimal farm scale and milk production in dairy farm is investigated in Mazandaran province. Therefore, information of 50 industrial dairy farms in Sari, Babol and Ghaemshahr County is gathered. In this study for estimating optimal scale of herd, Dawson and Hubbard model was used. The results show that optimal scale of milk production in Sari, Babol and Ghaemshahr is 304059.6, 315532.4 and 281210.6 Kg respectively, that according to average annual yield for each dairy cow, optimal scale of herd in these counties is 72, 72 and 68 respectively. According to the results, improvement in production scale for achieving optimal production scale is suggested.