مجله علوم دامی ایران
سال پنجاهم شماره 1 (بهار 1398)

The methane production from ruminant production system was estimated to reach 250-500 L per animal per day which has been reported to contribute up to 8-10 % of global warming during the next 50-100 years. The aim of this study was to investigate the correlation among methane emission (predicted by volatile fatty acids) with milk production traits, its components and breeding values (BV) of these traits in Iranian Holstein cattle. The rumen digesta was obtained from 150 cattle through stomach tubing and this population divided into 2 groups with 75 cattle in each (the groups have different milk production BV). Data were analyzed by R.3.3.0. The results showed that methane emission per unit of milk and fat were different in the two groups (P<0.0001). Also, the BVs of milk production, fat and protein traits and daily production of milk, fat and protein had weak to moderate negative correlation with methane emission per unit(P<0.05). The highest correlation was observed between daily production of fat with methane emission per unit of fat (-0.79) as well as daily milk production with methane emission per unit of milk (-0.62). These results showed that methane emission may be reduced by indirect selection per generation for the traits had a high correlation with the gas (daily production of milk and fat).

This experiment was conducted to investigate the effects of different levels of dietary NDF in diets rich in plant oil (sunflower) on milk performance and feeding behavior of mid-lactating Holstein dairy cows. Four primiparous (BW: 525±30 kg; DIM: 103±6) and four multiparous (BW: 587±88 kg; DIM: 99±12) cows were used in a 4×4 replicated Latin square design with 21-d experimental periods. Cows were received 1 of 4 four treatments: 1) 31% fiber (NDF) and no supplement plant oil, LF, 2) 31% fiber with 2% supplement plant oil, LFO 3) 35% fiber with 2% plant oil, MFO 4) 39% fiber with 2% plant oil, HFO. Daily dry matter intake (DMI), milk yield and composition, blood metabolites, dry matter digestibility, rumen fluid characteristics and BW variations were determined. There was no significant different in milk production among diets. Milk fat (P<0.01) and protein (P<0.05) concentrations were significantly affected by treatments. Dry matter intake and DM digestibility were higher (P<0.01) in LFO diet. The cows fed HFO had higher NDF digestibility (P<0.01). Total VFA and acetate concentration were greater for HFO diet and propionate concentration was greater for LFO diet (P<0.01) than the others. Rumen fluid pH was increased by increasing dietary NDF concentration (P<0.01). Chewing activity was positively affected by increasing concentration of dietary NDF (P<0.01). This study showed that diets rich in plant oil and low concentration of NDF induce the milk fat depression in mid-lactating cows.

This study was aimed to determine the effect of dietary Curcumin supplementation on the plasma lipid profile and some sperm quality parameters in broiler breeder roosters. In a completely randomized design, a total of twenty-eight 51-weeks-old Ross-308 roosters were randomly assigned to 4 treatment groups (n=7) and individually caged for 9 successive weeks. Treatments were different levels of Curcumin that were added to a basal diet including: T1, control (no Curcumin supplement), T2, 0.006%; T3, 0.012%, and T4, 0.018% of the diet. To determine plasma lipid profile, blood samples were collected from five birds/treatment at the end of the trial. Also, semen samples were weekly collected from each bird during the experiment, and sperm motility and plasma membrane integrity were evaluated. The results showed that concentrations of the plasma glucose, triglyceride, total cholesterol, and LDL were decreased, and concentrations of HDL were increased in T3 and T4 groups compared to the control group (P < 0.05). There were no significant differences in plasma lipid profile and plasma concentration of glucose between T1 and the control group (P<0.05). Sperm plasma membrane integrity and motility were linearly improved in treated groups compared to the control (P<0.05). The highest decrease in plasma lipid profile and most improvements in sperm motility and plasma membrane integrity was observed in T4 groups compared with other groups. In conclusion, considering all the measured parameters, dietary supplementation of 0.018% Curcumin had the best response on modifying plasma lipid profiles and improving sperm quality characteristics compared with other treatments.

Iranian indigenous goats are considered as one of the most valuable genetic reserves and it is important to keep their genetic diversity. The mitochondrial genome in an ecotype and comparing it with other ecotypes can provide an appropriate mesures of the diversity of the population. The purpose of this study was to investigate the genetic structure and phylogenetic relationships analysis of mitochondria HVR1 in four populations of indigenous goats in Iran including of Sistani, Pakestani, adani and Black Lori goats (Each of them has 4 heads) and compare to the other species of goats in the world. Total DNA extraction was performed using phenol-chloroform method and proliferation reaction was performed using a pair of special primers. Proliferation products were sequenced after purification by Sanger method. All of these sequences with17 sequences of the mitochondrial genome of other non Iranian goat ecotypes obtained from the National Center of Biotechnology Information (NCBI) were used for genetic analysis and phylogenetic tree mapping. Studying of HVR1 region of the mitochondrial genome in different goat populations, 123 polymorphic sites and 16 haplotypes were identified. The analysis of molecular variance showed that 15% of variation belongs to between populations and 85% within populations. All Iranian goat populations used in the present study were grouped in the Haplogroup group A, which were commonly found in world ecotypes. The values ​​of the D and Fs statistics of the Tajima test were negative (-2.14 and -9.55 respectively) in the recent study, which may be due to the small size of the sample size. The results of this study showed that HVR1 region of the mitochondrial genome is a suitable tool for genetic studies and Haplogrouping of Iran and Non Iranian goat populations.

The aim of this research was to study gene expression profiling and differential analysis between Bos taurus (Holstein) and Bos indicus (Cholistani) subspecies. The transcriptome was assembled through aligning and mapping the RNA-Seq reads that have already been sequenced by next generation sequencing technology. Among 24616 genes and 26717 transcripts, only 41 genes were differently expressed. The highest digital gene expression was measured for a mitochondrial gene (ENSBTAG00000043545), and was only expressed in the Cholistani population. One gene had two differentially expressed isoforms. Gene pathway analysis indicated that the differential expressed genes included in pathways, are particularly related to immunity, response to stress and angiogenesis. These pathways have probably resulted in adoption to various climatological conditions and perceptible phenotypes in the studied subspecies during their evolution.

This experiment was conducted to evaluate the effect of different levels of iron (0, 40, and 80 mg/kg) with iron sulfate source (FeSO4) on performance, internal organ weights and immune response of boiler chicks in periods of whole production (w: 1-42 days of age), grower and finisher (GF: 11-42 day of age) and finisher (F: 25-42 day of age) using a 3×3 factorial experiment. The results showed that the utilization of 80 mg/kg FeSO4 significantly (P<0.05) decreased daily feed intake of broilers during T period. The addition of 40 mg/kg FeSO4 into the diet significantly decreased the relative weights of jejunum, ileum and whole intestine (P<0.05). The relative weight of bursa of Fabricius was higher in chicks fed 40 mg/kg FeSO4 supplement in F period as compared to birds fed control diet (P<0.05). The positive effects was observed on blood monocytes in chicks fed diet containing FeSO4 supplement during F period compared to T period (P<0.05). Furthermore, the inclusion of 40 and 80 mg FeSO4/kg diet linearly (P<0.01) increased blood lymphocytes percentage of broilers. According to the results of this experiment, it seems that the utilization of 40 and 80 mg/kg FeSO4 can improve carcass quality by reduction of small intestine weight and have beneficial effects on immunological responses of broiler chicks especially during F period.

The current study was conducted to determine the effectof feed form (mash, pellet and extrude) on energy and protein efficiency, intestinal morphology and microbiology in broiler chickens. Energy and protein efficiency and European efficiency factor were calculated during the experiment period and jejunum morphology and relative length of intestine, microbial population, volatile fatty acids, viscosity of ileal were determined at 42 days of age. The results have shown that the effect of feed form on jejunum morphology (crypt depth (CD), serosa thickness, villous height (VH) and villous width (VW), VH:CD, length and relative length of intestine, microbial population (spore former bacteria, lactobacilli,colibacilli, total aerobic bacteria) of ileal digesta was not significant (P>0.05). The values of viscosity and volatile fatty acids (butyric, isobutyric, valeric, isovaleric) of ileal digesta was higher and values of pH, ascetic acid was lower in mash diet form in comparison to pellet and extrude diet form (P<0.05). Energy and protein efficiency and European efficiency factor were higher in extrudes diet form in comparison to mash and pellet feed forms in total experiment period (P<0.05). Our findings have shown that that extrusion and pellet feed forms had positive results on volatile fatty acid profile, intestinal contents’ viscosity, energy and protein efficiency and European efficiency factor in comparison to mash feed form in broiler chickens.

This study was conducted to determine the amylase gene expression in liver and pancreas tissues of broiler chicks fed with two levels of oak acorn(OA) fruit. A total of 264 broiler chicks were fed a control diet (without oak) and diets containing 15 and 20% OA. At the end of starter and finisher period, 6 birds from each treatment were randomly selected and Tissue samples were taken from their pancreas and liver. REST and SAS software were used to analyze gene expression. The 2004 Bestkeeper software was also used to determine the sustainability of β-Actin gene expression. Results showed that β-Actin gene was not affected by sex, age and experimental treatments. Thus, it was used to normalize the gene expression data. At 21d of age, the level of mRNA of the pancreatic amylase gene was significantly higher in broilers fed with 15% OA compared to the control group (p<0.05). On d 42, significant differences in expression of liver and pancreas amylase gene were not observed (p>0.05). Also, feeding birds with diet containing 20% OA increased the relative weight of pancreas (p<0.05). In conclusion, the results showed that amylase gene expression in birds fed diets containing 15% OA significantly increased at 21d of age. In other cases, genes expression was not influenced by experimental treatments.