مجله تولیدات دامی
سال نوزدهم شماره 1 (بهار 1396)

The objective of this study was to compare three parametric (GBLUP, BayesB and RKHS) and two resampling (Bagging GBLUP and Random Forest) statistical methods in genomic prediction of traits with different genetic architecture. A genome consisting of three chromosomes, 1 Morgan each, was simulated on which 5000 SNPs and 50, 100 and 200 QTLs were distributed. The substitutions effects of QTLs were modeled with normal, gamma and uniform distributions with a level of heritability equal to 0.30. The predictive performance of statistical models was evaluated using the correlation between predicted and true breeding values as well as the regression of predicted values on true breeding values. In the target population, Random Forest resulted in overestimation of estimated regression coefficients while GBLUP, BayesB and RKHS led to an underestimation of regression coefficients of true breeding values on predicted breeding values. In exception of Bagging GBLUP, the performance of all statistical methods was the same in three gene effect distributions. However, the performance of GBLUP and BayesB was better than other statistical methods. A reason for this superiority could be the additive architecture of simulated traits. In conclusion, GBLUP and BayesB were superior over resampling methods in genomic predictions.

This study was conducted to investigate the Single nucleotide polymorphism of STAT1 gene by PCR-RFLP technique and association of genotypes with milk production traits in Brown Swiss dairy cattle. The blood samples of ninety-eight cows were collected randomly from tail vein. The DNA was extracted with Cinagene kit (PR881612C). Fragment of 314 bp in 3'UTR of STAT1 gene was amplified by PCR and digested by Pag1 restriction enzyme. Genotype frequencies were calculated by PopGene software (version 1.31). The SAS 9.1 software was used for statistical analysis and the mean of traits was compared by Duncan test. The genotype frequencies of TT, TC and CC were 0.23, 0.25 and 0.52, respectively. The T and C allele frequency were 0.355 and 0.645, respectively. The expected heterozygosity was estimated 0.458. Result of Chi-square showed that this locus was not in the Hardy Weinberg equilibrium (P

Ascites Syndrome is a costly metabolic disorder that has been linked to intense selection on growth rate and low feed conversion ratio in broilers. This Syndrome has become one of the most frequent causes of mortality within the broiler industry and leads to substantial economic losses and reduced animal welfare. To identify genes and genomic regions associated with Ascites Syndrome, genome wide association study was performed by the chicken 60K SNP panel on 101 birds from a F2 chicken population derived from the reciprocal cross between Arian broiler Line and Azerbaijan native fowls. Genomic best linear unbiased prediction procedure was used to calculate associations between each SNP and ascite related traits. Several SNPsfor the ratio of right ventricular to total ventricular, an indicator for Ascites syndrome, reached the suggestive threshold (8.25×10-5) on chromosome 7. Two SNPs detected within CCDC141 and OSBPL6 genes were previously reported for human heart disorder. There are a large number of genes in this region (12745561-14602723) on chicken chromosome 7 that are related to hypertrophic cardiomyopathy, heart rate and human heart disorder. Selection for ascites resistance in broiler chicken using these findings could accelerate the genetic progress.

The aim of this study was to compare copy number variation (CNV) in some Italian sheep breeds with Holstein cows. Blood samples were collected form 580 Holstein bulls and 360 different Italian sheep breeds and then DNA was extracted. The SNPs genotypes across the genome were determined by ovine and bovine 50K BeadChip in both species. By PennCNV, the 904 CNV with mean and median size of 154.7 kb and 103.7 kb in sheep and 744 CNV with mean and median of 213.7 kb and 124.5 kb in Holstein were detected, respectively. A total length of this variation were 8.5 Mb in sheep and was 80 Mb in cattle. After merging similar regions, the 35 and 141 non- unique copy number variation regions (CNVR) were detected in sheep and cows, respectively which 20% of sheep’s CNVRs overlapped with cattle’s CNVRs. In addition to, these regions in Sheep genome were partially or completely overlapped with 40 RefGen & 62 QTL in cattle and 110 RefGen in Human. CNVRs distribution in both species was more in subtelomeric and pericentromeric regions. According to these results, it could be possible to use bovine CNVRs which were closely linked to genes for characterizing functional genes and QTLs in sheep, however more studies are need in this regards.

Objective of this study was to investigate milk production cost, milk sale price and pricing system of Iran in comparison with other countries. To do this, production data and economic information gathered by news and information technology of Iranian poultry and livestock industries ( ITPNews), Animal Breeding Center of Iran, Iranian National Standards Organization, Iran Dairy Industries Society, International Dairy Federation and International Farm Comparison Network (IFCN) Dairy in 2015, were used. Ignoring milk protein, somatic cell count and temperature as well as occasional and inappropriate payment for milk fat and total bacterial count along with low base levels for standard milk fat (3.2) and protein (3.0) percentages comparing with international averages ( 3.8 % fat and 3.3% protein) were the main drawbacks of Iran current milk payment system. The results showed that because of paying less attention to the quality, the difference in raw milk payment price was about US$ 0.04. However, it was roughly US$ 0.07 higher that the IFCN milk price indicator. Nevertheless, the IFCN milk: feed price ratio showed that Iran dairy farms similar to international ones were not in a sustainable situation. Finally, to solve the issues, a (compositional and hygienic( quality based milk payment system has been presented. Results obtained in the study can be useful to improve interactions between dairy farmers and factories.

This study was conducted to investigate the effects of energy density in dry period on subsequent milk production. Milk production and milk components of 2143 milking cows were used and NEl of the far-off and close-up period’s diets were 1.35, 1.45, 1.55, and 1.44, 1.54, 1.65 Mcal/kg of dry matter. Descriptive statistics of herds were described. The results were showed as least square and standard error of means in early lactation (120 day) and whole lactation period. As energy density increased in the far-off and close-up periods, there was no difference in milk yield in early lactation period, but there was a linearly increase in whole lactation period (P

The aim of this experiment was to study the effects of two levels of barley silage particle sizes and two levels of non-forage fiber on feed intake, nutrients digestibility, rumen parameters and feeding behaviors in sheep. Whole-plant barley was harvested at 28% moisture in 8 and 16 mm theoretical chop lengths to prepare short and long silages. Four male sheep with the weight of 46±7 kg were used and experimental diets were: 1) coarse barley silage diet without beet pulp, 2) coarse barley silage diet with 20% beet pulp, 3) fine barley silage diet without beet pulp and 4) fine barley silage diet with 20% percent beet pulp. The NDF intake was affected by beet pulp levels (P=0.05) and the highest NDF intake was in sheep fed with fine barley silage diet with 20% beet pulp (P

The effect of partial replacement of barley with sugar beet pulp (SBP) with and without roasted canola seeds (RCS) on the performance, morphology, VFA and digesta pH in the small intestine of finishing lambs was investigated. In this study 24 Arbia male lambs with average body weight of 23.7±2.5 kg were used in a 2 × 2 factorial experiment over 84 days. Treatments were carbohydrate factor (barley or SBP) and roasted canola seed (with and without RCS). Partial replacement of barley with SBP significantly increased average daily gain (P

Two experiments were carried out to determine the physicochemical properties of soy oil sources and investigate the effect of their use in broilers diets on growth performance. In the first experiment, fatty acids composition of the experimental oils was determined and then the apparent metabolizable energy (AME) of oils was estimated through two methods, including multiplying the digestibility of the oil by its gross energy value as well as subtracting AME value of the basal diet from diets containing the oils using Leghorn mature roosters. In the second experiment, the effects of four dietary treatments containing 5% of each oil source was studied on the performance of Ross 308 broilers, replicated 5 times, using a completely randomized design. Linoleic acid content turned out to be 51.46% in soybean oil (SO), 11.35% in hydrogenated soybean oil (HSO), 32.53% in recycled soybean oil (RSO) and 40.03% in acidulated soybean oil soap-stock (ASO). The AME of the oils obtained by multiplying method for SO, HSO, RSO and ASO appeared to be 8920, 8733, 8602 and 7836 kcal/kg, respectively. When calculated by subtracting method, the AME of the oils turned out to be 9016, 8794, 8765 and 7906 kcal/kg, respectively, which indicates higher values obtained from the latter method than former one. Moreover, HSO improved feed intake compared with SO (P

In order to study the impact of different levels of dietary metabolizable energy and crude protein on performance and nitrogen and energy metabolism of Japanese quail during growth period, 360 day-old Japanese quails were used in a 3×3 factorial experiment with three levels of metabolizable energy (2750, 2850 and 2950 Kcal/kg) and three levels of crude protein (24, 26 and 28 percent) in a completely randomized design with four replicates and 10 birds in each replicate. The feed intake and body weight gain were measured weekly and feed conversion ratio was calculated. The nitrogen intake, excretion and retention as gram per bird per day, percent of nitrogen intake and gram nitrogen per kilocalorie per metabolizable energy consumed and dietary apparent metabolizable energy content were measured during 26 to 28 days of age period. The results of this study showed that birds fed diet containing 2850 kcal/kg metabolizable energy and 26 percent crude protein had significantly (P

This experiment was conducted to evaluate the effects of physical form, barley variety and enzyme addition on Ileal digestibility, apparent metabolizable energy (AME) and energy efficiency of broiler chickens.The experiment was carried using a factorial experiment with a completely randomized desiegn. Factors were barley varity (Fajr, Reyhaneh, and Yosef), diet form (mash or pellet) and enzyme level (0 and 0/05 g/kg dry matter). Here 927 one day-old Ross 308 broiler chickens were assigned to 12 treatments, 3 replicates and 27 chickens in each replicate. The results of experiment indicated that the digestibility of nutrients, AME, apparent metabolizable energy corrected to zero nitrogen retention (AMEn) and energy efficiencies (NE/AMEn) affected by barley variety (p 005), NE, AME and AMEn (p

The effect of dietary olive leaf in diet at different periods of breeding was studied on growth performance and ascites incidence in broiler chickens. A total of 336 one day-old male broiler chickens (Arian) used in complete randomize design with 6 treatments, 4 replications and 14 birds in each replication. The period of experiment was 42 days. The rations were supplied base on recommendation of Arian broiler management guide in three phase of feeding. In each phase, tow diets were provided with 0 (control) and 1 percent of olive leaves dried in diet. The treatments were diets:1) control, 2) from 1 to 14 days olive leaf, 3) from 1 to 21 days olive leaf, 4) from 1 to 28 days olive leaf, 5) from 1 to 35 days olive leaf, 6) from 1 to 42 days olive leaf. The effects of treatments were not significant on final body weight, daily feed intake and feed conversion ratio. The mortality due to ascites syndrome was reduced in treatments of olive leaf 1 to 14 and olive 1 to 42 (P

Effect of different levels of ginger (Zingiber officinale) and Protexin® probiotics on performance, humoral immune response and Ileal microbial population were evaluated using 360 birds in a completely randomized design as 2 × 3 factorial arrangement with 3 levels of ginger powder (0, 2.5 and 5 g per kg), and 2 levels of probiotics (0 and 150 mg per kg) in 6 treatments and 5 replicates of 12 birds for 28 days. Birds consumed greater amount of diet containing 2.5 g/kg ginger (P

This study was carried out to examine the effect of supplementation of canola and fish oils (5% fish oil, 3% fish oil 2% canola oil, 2% fish oil 3% canola oil and 5% canola oil) and Satureja khuzistanica essential oils (SkEO) (0 and 400 mg/kg), into a basal diet on productive performance, meat cholesterol, lipid stability and certain blood lipid components in broiler chickens raised under normal and heat stress conditions during day 22 to 42 of age. The experiment was conducted in a 4×2×2 factorial expriment using 640 one-day-old Ross 308 chicks in a completely randomised blocks design with 5 replicates of 8 birds in each replication. Oil source significantly decreased FCR, serum LDL and cholesterol content in thigh and breast muscles at day 42 of age. Inclusion of 400 mg/kg SkEO in diet significantly increased daily weight gain and decreased cholesterol content and TBARS concentration in thigh and breast muscles in heat stressed chicks. Heat stress condition significantly decreased FCR and increased TBARS as well as cholesterol content in breast muscle and serum cholesterol concentration during day 22 to 42 of age. It was concluded that supplementation of 400 mg/kg SkEO and canola oil into diet could have a positive effect on productive performance and reduce the meat and serum cholesterol concentration in broiler chicken.

The aim of this study was to compare the effect of glycogenic and/or lipogenic diets fed in Baluchi ewes treated with an estrus synchronization method to reduce delivery distance and improving reproductive parameters. Ninety heads of Baluchi ewes selected and randomly placed into three parallel groups. Each ewe of group was fed in with three different diets based on the fat and starch sources. In order to do the estrus synchronization, all ewes were put CIDR in 30 day of the trial. After 14 days, they were removed, then four hundred IU eCG hormone were injected. As soon as estrus signals was observed, ewes were inseminated. Ultrasonography was done to observe the number of dominant follicle, CL and pregnancy diagnosis. After parturition, reproductive parameters like lambing and twining rate were analyzed. The most of examined ewes showed clearly estrus signals. The consequence of ovary sonography did not indicate significant effect in average of dominant follicles numbers among the experimental diets. The number of dominant follicles was increased significantly from time of estrus to artificial insemination. Ovulation, pregnancy and twining rate were considerably (P

In order to investigate the effect of different levels of Saturieja khuzistanica powder on the histomorphometric of testis, 36 native roosters (40 week age and BW 2039±293gr) was used. Three levels of Saturieja khuzistanica powder (0, 20 and 40g/kg) over 8 weeks was added to base diet. After eighth weeks, roosters were slaughtered and testes were removed from abdominal cavity. Tissue sections of testis after stained by Hematoxylin-Eosin were used to measure number of primary spermatocyte, secondary spermatocyte, spermatid, Sertoli cells, number of tubules and testicular vessels using optical microscope. In treatment with 40gr Saturieja khuzistanica powder per kg diet, number and density of vessels in testicular section were decreased compared to the control group (P

In this study antioxidant effects of olive leaf extract (OLE) in comparison to vitamin C and E on chilled-stored (at 5 °C) bovine sperm was evaluated. The sperm samples collected from epididymis of ten Holstein bovine testis with 3-5 years old, and were diluted with egg yolk and sodium citrate containing 0.5, 1.0 and 2.0 mg/ml of OLE as well as 2 mg/ml vitamin E and C. Addition of OLE significantly reduced sperm motility (P

The objective of this experiment was to study the effects of dietary nano-selenium supplementation on the glutathione peroxidase activity and sperm quality and quantity parameters of Arabian rams. In this experiment, twelve Arabian rams with an average weight of 73±3 kg and age of two to four years were used. Animals were divided into three groups: the control group (without -nano Selenium) and two experimental groups that received 0.4 and 0.8 mg nano-selenium per kg dry matter, respectively. The results showed that significant increase in semen selenium concentration and semen glutathione peroxidase activity in group 0.8 mg nano-selenium compared with the control group (P