مجله تولیدات دامی
سال بیست و سوم شماره 4 (زمستان 1400)

Understanding the genetic control of temperament as a complex trait and correlated with economic traits is one of the breeding goals in beefcattle industry. The aim of the current study was genome wide association studies (GWAS) based on Gene set enrichment analysis fordetecting the loci associated with temperament traits in Brahman cattle breed. Therefore, 1370 Brahman cattle and phenotype recordsassociated with temperament traits including Exit velocity, Pen Score, and Temperament Score were used. The evaluation of genome-wideassociation was carried out using PLINK package 1.90. The gene enrichment analysis was performed by the goseq R package for identifyingbiological pathways of nearby genes in selected candidate regions and finally, GO, Metacyc, KEEG, Reactome and panther databases wereapplied for bioinformatics analysis. By Gene set enrichment analysis, the biological pathways and candidate genes of neurotransmittersecretion (NRXN3 and CACNG3), Dopamine Neurotransmitter Release Cycle (PPFIA2), regulation of neuron projection development(GRID2), neuron projection (SLC8A1 and KCNQ2), Axonal growth inhibition (RTN4R), Neurotrophin signaling pathway (MAP2K2,MAP3K5 and PSEN1) and Focal adhesion (TLN2) were identified. The detected candidate genes played an important role in differentiationof synapse, neurotransmitters, neurological diseases and disorders, oxidative and environmental stresses, hormone receptors and glucosehomeostasis. Considering the confirmation of the previous region of genome wide association and the identification of new genomic regions,the findings of this study can be useful in the genetic selection of higher production cattle through calm animals.

The purpose of this study was to fit different nonlinear models to describe growth curve and selection the best model to describe a growth curve forcalves of Sistani calves. Body weight records of 241 calves (118 males and 123 females) collected by the Sistani Dairy Cattle Research Station ofZahak from year 2010 to 2017 were used. Four nonlinear models (Gompertz, Logistic, Richards, and Weibull) were fitted to the body weight recordsand the best model was selected by the goodness-of-fit criteria (Mean square error, Bayesian information criterion, Akaike information criterion andcorrected coefficient of determination). According to goodness-of-fit criteria, Richards model was the most appropriate model to describe the growthcurve in male and female calves. The effect of sex on curve parameters was significant in many functions (P <0.05). Logistic and Richards models hadthe highest and the lowest initial weight parameter, respectively. Male calves reached to the inflection point in a higher age and weight compared tofemale calves. According to the results of this study, a proper model can be used to study the growth pattern of this breed in order to better nutritionalmanagement and selection for rapid growth with high accuracy.

The aim of present study was to investigate the effect of selection against ascites syndrome on different traits body growth, internal organs, and bloodparameters in a broiler line. Therefore, by classifying different families based on the frequency of ascites under intense ascites inducing condition(AIC), 10 susceptible families (SUS) and 10 resistant families (RES) to ascites were selected and another set of offspring from the same families werebred under normal commercial condition (NCC). This process of selection and cross validation was carried out twice in the two distinct generations.The genetic relationship of different traits, the difference in the frequency of ascites between AIC and NCC, and the difference between different traitsin SUS and RES were performed by correlation statistics, Chi-square test, and GLM procedure of SAS software (version 9.1), respectively. Thecorrelation between ascites susceptibility in different families indicated that families that showed more ascites under AIC also had more ascites underNCC. Comparative study of different traits in susceptible and resistant groups showed that in SUS, body weight, growth rate and respiratory capacitywere significantly lower and blood partial pressure of carbon dioxide was significantly higher than RES (P<0.05). In the present study it was shownthat selection against this syndrome not only does not reduce growth rate in the investigated broiler line, but also improves growth traits and resistanceto this syndrome in the mentioned line.

The aim of this study was to investigate the changes of some blood biochemical parameters in Lori-Bakhtiari ewes during different monthsof pregnancy and the influence of fetus numbers on these parameters. For this purpose, 20 ewes of Lori Bakhtiari breed were selected andmated with fertile rams. One month before mating and in the first to fifth months of pregnancy blood samples were collected from ewes andbiochemical and enzymatic parameters including calcium, phosphorus, magnesium, urea, creatinine, total bilirubin, AST, ALP and GGTwere measured. The concentration of calcium and AST activity were constant at the times of the study, but they increased in the last monthof pregnancy (P<0.05). Magnesium concentration increased in second month of pregnancy (P<0.05) and phosphorus concentration wasdecreased during pregnancy compared to the month before mating (P<0.05). Creatinine concentration decreased in the second and thirdmonths of pregnancy compared to other months of pregnancy (P<0.05). Total bilirubin and urea concentrations increased during fourthmonth and the second half of pregnancy, respectively (P<0.05). GGT activity was almost stable during study period but decreased in thefourth month of pregnancy (P<0.05), and ALP enzyme activity showed increasing trend during pregnancy period (P<0.05). The meanconcentration of the studied parameters in singleton ewes was not significantly different from twins (P <0.05). Based on the results of thisstudy, blood biochemical changes in Lori Bakhtiari ewes can be used to assess their physiological status during pregnancy.

Effect of Basil powder and extract on yield and carcass characteristics, relative expression of heat shock protein gene (HSP70) and someblood parameters of broiler chickens under heat stress using 160 Ross 308 one-day-old broiler chicks in a completely randomized designwith 5 treatments and 4 replications (8 chickens per replication), was evaluated for 42 days. Treatments included: 1- Basic diet (control), 2-Basic diet+ Vitamin C (250 mg per kg of grain), 3- Basic diet + 25 mg of Basil powder (per kg of grain), 4- Basic diet +50 mg of Basilpowder (per kg of grain), 5- The use of Basil extract (1 ml/liter water). Feed intake, body weight gain, feed conversion ratio, carcasscharacteristics, blood parameters and relative expression of HSP70 gene in blood were measured. The effects of treatments on bloodparameters and carcass characteristics were not significant. Relative expression of the HSP70 gene in the blood was significantly reduced inall treatments compared to the control (P<0.05). Based on the results, basil powder and extract reduce the negative effects of heat stress inbroilers, so their use in broiler diets is recommended to prevent heat stress.

In order to evaluate the response of broiler chicks to different levels of dietary ideal protein (Ross 308 strain recommendation and 10% less) anddigestible valine to lysine ratio (71, 74, 77, 80, and 83%) in the starter period (one to 10 days of age), a study was performed using 500-day-old malebroilers in a 2×5 factorial arrangements based on a completely randomized design including 10 treatments and 5 replications. The results showed thatreducing dietary ideal protein level increased body weight, feed intake and improved feed conversion ratio (P<0.01). The percentage of bone ash andcalcium content also increased significantly with decreasing dietary ideal protein (P <0.05). The reduction of the dietary ideal protein level decreasedthe concentrations of serum cholesterol, glucose, total protein, albumin, globulin, calcium, and phosphorus (P<0.05). The highest average body weightat 10 day of age, weight gain, carcass and breast percentages and the lowest feed conversion ratio were observed at 74% of digestible valine to lysineratio (P<0.05); while the highest average feed intake, thigh percentage, bone ash and calcium percentage were obtained at 77% of digestible valine tolysine ratio (P <0.05). No significant interaction was observed between the two experimental factors except for the carcass percentage traits (P<0.05)and serum phosphorus concentration (P <0.01). In conclusion, based on the results of this study, a 10% reduction in dietary ideal protein levels ispossible by maintaining ideal ratios of essential amino acids. The proper ratio of digestible valine to lysine is recommended to be 74% based onperformance indices and carcass traits, and 77% based on bone traits.

In this research the effect of Bioplus B2 probiotic and galactooligosaccharide prebiotic (GOS) on performance, egg quality, and some bloodparameters of commercial laying hens were investigated in a sample of 216 hy-line laying hens (w36) with the same average weight aging 50to 62 weeks for a period of 12 weeks in a completely randomized design with 6 treatments, 6 replications and 6 hens per each replication inthe cage system. Experimental treatments included 1) without additives (as control), 2) diets containing 0.1% Bioplus B2 probiotic, 3) to 6)diets; containing, 0.05, 0.1, 0.15 and 0.20 % of galactooligosaccharides prebiotic, respectively. The results indicated that both egg weightand mass was increased significantly (P<0.05) in the Bioplus B2 probiotic treatment. Egg production percentage, feed intake and feedconversion ratio were not significantly influenced by treatments. Using galactooligosaccharide at the levels of 0.05, 0.1 and 0.2 percentimproved dry eggshell weight significantly while the levels of 0.05, 0.15 and 0.2 percent increased eggshell weight per unit area compared tothe control (P<0.05). Total protein and albumin of serum increased in the Bioplus B2 treatment (P<0.05). Using Bioplus B2 probiotic and0.15% galactooligosaccharide significantly decreased blood cholesterol level (P<0.05). In general, the results showed that the using ofprebiotic galactooligosaccharide at the level of 0.15 % increases the weight of eggshell per unit area, decreases the blood serum cholesterol,and improves some performance traits compared to control group, therefore it can be used instead of probiotic Bioplus B2.

The effects of different sources of copper supplementation on growth performance, some blood biochemical and immune parameters,microbial population of small intestine and meat quality were investigated with using of 240 male broiler chicks in a completely randomizeddesign with 5 treatments and 4 replicates from 1 to 42 days. Treatments consisted of control treatment (basal diet without copper supplement)and four diets containing 16 mg/kg of copper-glycine, copper-sulfate, copper-nanochelate and copper nano-glycinec. The results showed thatthe use of different sources of copper had no effect on growth performance, some blood biochemical parameters and percentage ofheterophil, lymphocyte, white blood cell, antibody titer against Newcastle disease, cholesterol, triglycerides and water holding capacity andpH of meat of broilers. Gastrointestinal relative weight in birds fed with diet containing copper-glycine was lower than the birds receivingcopper-nanochelate (P<0.05). The total microbial population of ileum in birds fed diets without copper and copper-sulfate was higher thanbirds receiving diet containing copper-glycine (P<0.01). Meat malondialdehyde concentration of birds fed with diets containing copperglycineand copper nano-glycine after 6 day of storage at refrigerator was lower than other birds (P<0.01). According to the results, the useof 16 mg/kg of copper from organic, mineral and nano sources in the diet has no effect on growth performance, immune system and ilealmicrobiota in broilers, but the use of copper-glycine and copper nano-glycine supplements in the diet reduces the oxidation of meat.

This experiment was performed to investigate the effects of Ziziphus jujube and Elaeagnus angustifolia powder on growth performance, bloodmetabolites and meat quality of broiler chickens at high temperature conditions. In this experiment, 160 one-day-old male broiler chickens of Ross308 were used in a completely randomized design with 4 treatments and 4 replicates of 10 birds per each. Experimental treatments were including: 1-control (basal diet), 2- basal diet + 0.75% Ziziphus jujube, 3- basal diet + 0.75% Elaeagnus angustifolia powder, and 4- basal diet + combination ofZiziphus jujube and Elaeagnus angustifolia powder (0.75% of each). At day 25 of age, with the onset of heat stress, the chicks were exposed to 34±2 °C for eight hours daily from 9 a.m. to 5 p.m. The results showed that the effect of treatments on growth performance traits was not significant(P≥0.05). Also, the relative weight of carcasses and internal organs except liver were not affected by experimental treatments. The lowest relative liverweight was observed in the control group (P≤0.05). The addition of Ziziphus jujube and Elaeagnus angustifolia in the diet significantly increasedglutathione peroxidase and decreased blood glucose compared to the control group (P≤0.05). The highest amount of water holding capacity andlowest dripping loss and cooking loss were observed in birds fed Ziziphus jujube mill and Elaeagnus angustifolia (P≤0.05). Based on the results of thecurrent experiment, although the inclusion of 0.75% of Ziziphus jujube and Elaeagnus angustifolia had no effect on growth performance of broilerchicken, but improved blood metabolites and meat quality traits.

The study aimed to investigate the effect of asparagus extract on quality semen of Arabian rams at different storage times at a temperature of 4degrees Celsius. Sperm collection was performed from 10 Arab rams with an average age of 2.5 years per week (once a week) for six weeks. Afteradding 0, 1.5, 3 and 4.5% asparagus extract to the semen diluent, sperm quality parameters were evaluated at 0, 24, 48, and 72 hours after storage inliquid condition. At zero hour, sperm viability in diluent had 3% asparagus extract was higher than diluent containing 0 and 4.5% extract (P<0.05).After 24 hours of semen storage, the parameters of total motility, progressive motility, plasma membrane integrity and viability were higher in spermdiluent containing 1.5 and 3% of the extract (P<0.05). Qualitative parameters of sperm in 48 hours after sperm collection and storage in diluentcontain 3% of extract had significant and better performance (P<0.05). The highest rate of plasma membrane integrity, progressive motility and totalsperm motility was observed in diluent containing 3% extract in 72 hours after sperm storage (P<0.05). According to the results of this study, the useof asparagus extract in the diluent at the rate of 3% improves the sperm quality of Arabian rams after cooling conditions.