Iranian Journal of Animal Science
Year:2016 | Volume:47 | Issue:2 |Papers Count:18

Diacylglycerol acyltransferase1 (DGAT1) is a key enzyme in synthesis of triglycerides. A transition mutation resulting substitution of guanine by adenine in DGAT1 gene and substitution of lysine by alanine in diacylglycerol-acyltransferase enzyme in cattle has a major effect on milk yield and milk composition traits. In this research, the polymorphism of the region spanning exon 3 to exon 17 of the DGAT1 gene of three indigenous Iranian buffalo populations was investigated. A total number of samples of 200 buffaloes (Khuzestani, Shomali and Azari) were collected to extract DNA and the desired fragments were amplified by polymerase chain reaction (PCR). Genotyping was performed using direct sequencing and analyzed by BioEdit software. Sequence analysis showed novel SNPs in comparative to the reference sequence GenBank (DQ886485) at nucleotide positions g. 6097A>G, g. 7036C>T, g. 7338G>A, g. 7710C>T, g. 8087C>T, g. 8259G>A, g. 8275G>A and g. 8426C>T of DGAT1 gene in buffalo populations. A comparison with Indian buffalo revealed three exonic SNPs, one of which was non-synonymous. A Unique 22 base insertion has been observed in the intron 10. The results described here genetic diversity and could be useful in genetic and breeding programs in Iranian buffalo.

This experiment was conducted to consider the effects of maturity and cutting time on chemical composition and available protein content of alfalfa hay for dairy cows. . Alfalfa hay harvested at two maturity stages (Pre-bloom and Early bloom) and two cutting times (Morning and Afternoon). Available protein was predicted using NRC (2001) and DVE/OEB (1994) models. In the NRC model (2001), alfalfa hay harvested pre-bloom and in the afternoon had higher microbial protein synthesized in the rumen from energy and absorbable microbial protein and lower ruminal degraded protein balance (P<0. 05). But, metabolizable protein content was not affected by maturity stage and cutting time (P>0. 05). In the DVE/OEB model, pre-bloom alfalfa harvested in the afternoon had higher fermentable organic matter, microbial protein synthesized from organic matter and absorbable microbial protein and lower ruminal degraded protein balance (P<0. 05). In conclusion, pre-bloom alfalfa hay harvested in the afternoon had higher available protein for dairy cows.

This study was conducted to investigate the effect of Bacillus subtilis and Licheni formis on broiler breeder performance and gastrointestinal health of their progenies. A total of 336 broiler breeder hens (Cobb 500) from 22 to 32 weeks of age were used in a completely randomized design of 2 × 2 factorial arrangement with four treatments, each with seven replicates. Dietary treatments included: 1) basal diet without probiotic and without Salmonella enteritidis inclusion; 2) basal diet without probiotic and oral inclusion of 1×106 cfu/bird and 1×108 cfu/bird Salmonella enteritidis in 26 and 30 weeks of ege, respectively; 3) basal diet containing 0. 4 gr/kg probiotic and without Salmonella enteritidis inclusion; 4) basal diet containing 0. 4 gr/kg probiotic and oral inclusion of 1×106 cfu/bird and 1×108 cfu/bird Salmonella enteritidis in 26 and 30 weeks of ege, respectively. The results showed that adding probiotic was increased fractional weight of yolk and liver (P<0. 05). The number of large and small yellow follicles were decreased significantly in response to the challenge with Salmonella compared with the control. The results of this study did not show any benefit of adding probiotic on performance of broiler breeder hens contaminated with Salmonella enteritidis.

This study was conducted to evaluate the relative bioavailability value of Mn proteinate and Mn oxide in broiler chicks. A total of 432 day-old Cobb 500 commercial male broiler chicks were randomly distributed into nine treatments with eight replicate pens of six chicks each. In a completely randomized design experiment with a 2×4 factorial arrangement of two manganese sources (proteinate and reagent grade of oxide) with four levels of supplemental manganese (35, 70, 105 and 140 mg/kg diet) was provided by the use of a basal diet (control). Diets were fed from day one to 21 d of age. Manganese sources did not affect feed intake, body weight gain and feed conversion ratio (FCR), but body weight gain and FCR had a quadratic relationship with supplemental dietary Mn level. Tibia, kidney and liver manganese concentrations increased linearly, with increasing dietary Mn level. Tissue Mn analysis indicated that the tibia response to dietary Mn level was the greatest, followed by kidney and liver organs. The slope ratio regression analysis for tibia manganese content with supplemental manganese level revealed that the relative bioavailability value of manganese proteinate to Mn oxide was 101. 7%. Thus, the relative bioavailability of Mn proteinate and Mn oxide was almost similar in this study.

Four mature stallions were used to study the effect of enzymatic antioxidant catalase on freezability of Turkmen stallion's sperm. Collected semen from stallions were processed and pooled before being divided treatments (200×106 sperm/ml) and diluted with extenders supplemented with different levels of catalase [0 (control), 100 U/ml (CAT100), 150U/ml (CAT150) and 200U/ml (CAT200)]. Extended and supplemented semen's were frozen according to a standard protocol. After thawing, motility, viability, membrane integrity, total abnormality and lipid peroxidation were assessed. Results showed that addition of 200U/ml catalase could improve progressive and total motility, viability, membrane integrity and decreased lipid peroxidation compared to control and other levels of catalase (p<0. 05). In addition, 150 U/ml catalase improved total motility, viability and decreased MDA concentration (p<0. 05). However, the addition of 100 U/ml catalase had no significant effect on sperm quality (p>0. 05). The results showed that different levels of catalase could not decreased total abnormality (p>0. 05). We concluded that addition of 200U/ml catalase could improve freezability of Turkmen stallion’ s sperm.

The purpose of this experiment was to investigate the effect of metabolizable energy (ME) levels, feed restriction (FR) intensity and duration in pelleted diet on performance, blood parameters and carcass characteristics in broiler chickens. A total of 480 male Ross 308 broilers were used in a 2×2×3 factorial arrangement with 12 treatments and 4 replicates. Experimental treatments included: two levels of ME, two levels of restriction intensity (90% and 85% of strain standard, intake), and three levels of restriction duration (8-21, 8-28 and 8-35d of age). Results indicated that increasing energy level improved body weight and feed conversion rate during 8-21 and 1-42 days of age, except for first week, that was decreased BW (P<0. 05). Broilers with 90% feed restriction during 8-14 and 8-21 were heavier (P<0. 05) and showed higher breast weight at d 21 than those received 85% feed restriction and during 8-28 d. A 14 d of restriction with higher energy level and 90% restriction increased carcass percentage and thigh weight at 42 d, while during 21 and 28 d of restriction, higher carcass and thigh weight were observed in 85% restriction with higher energy level (P<0. 01). Increasing energy level of diet induced lower TG level and breast weight, higher abdominal fat at d 42, also elevating serum glucose during 28 and 35 d of age (P<0. 05). In conclusion, increasing ME level in the diet with 90% feed restriction (90% of standard intake) during 3 weeks (8-28 d) improved the growth performance of broiler chickens.

In this experiment, randomized complete block design with four replications was used for evaluating of the effect of three feeding methods including: without feed restriction (control group), 6 hours feed restriction from 7 to 21 days and 4 hours from 22 to 28 days, 6 hours feed restriction from 7 to 14 days and 4 hours from 15 to 21 days on performance and ascites prevention of Arian male broiler chickens in six weeks. Body weight, feed intake, feed conversion ratio, mortality rate and the index of production efficiency were determined during the experiment. Hematocrit and blood parameters were measured at 35 days of age. Carcass characteristics and the right ventricle weight per total ventricle weight (RV: TV) ratios were determined and compared. Feed conversion ratio and production index was improved by feed restriction from 7-21 days (P<0. 05) at 42 days. With applying feed restriction ascites mortality was reduced (P<0. 05). Applied feed restriction methods on the amount of hemoglobin, red blood cells and hematocrit had no significant effect, but increased levels of corticosterone (P<0. 05). Although T3 hormone was not affected by feed restriction but T4 was increased by feed restriction from 7 to 21 days (P<0. 05). In addition, T3 to T4 ratios was reduced by feed restriction (P<0. 05). The results of this experiment indicated that, 6 hours feed restriction from 7 to 21 days and 4 hours from 22 to 28 days had the lowest ascites mortality and increased body weight insignificantly.

This study was conducted to evaluate the effects of inclusion of monensin alone or in combination with Methafix (a commercial product containing malate and fumarate) in the diets of lactating dairy cows on ruminal parameters and serum metabolites. Four multiparous Holstein lactating dairy cows (657± 12 kg of live weight; 133 ± 41days in milk) were assigned to one of the four dietary treatments. The first treatment was the control diet(C), second was control diet supplemented with 24 mg of monensin/kg of DM (M), the third was control diet supplemented with 5 g of Methafix/kg DM (ME) and the fourth treatment was C diet supplemented with 24 mg of monensin in combination with 5 g of Methafix/kg DM (MM). Dietary supplementation with Monensin alone or in combination with Metafix significantly decreased dry matter intake (P<0. 05), while the intake of crude protein (CP), neutral detergent fiber (NDF) and non-fiber carbohydrates (NFC) were not affected. Utilization efficiency of dry matter for milk production was higher in monensin and Methafix-supplemented cows than in control cows (P<0. 05). Dietary supplementation with monensin decreased rumen concentrations of acetate and the ratio of acetate to propionate (A: P; P<0. 05). Serum concentration of triglycerides (TGs) was higher in M-fed cows compared to the C and ME-fed cows (P<0. 05). Serum concentration of total proteins (TP) was higher in ME-fed cows than in the C-fed cows (P<0. 05). Feeding dairy cows with a combination of monensin and Methafix increased serum concentration of TGs and TP compared to the control animals (P<0. 05).

In this research to investigate of the effect of tannin`s type and level on rumenal degradation of soybean meal (SBM) and canola meal (CM), two experiments have be done. At first experiment supplements were treated by semi-pure tannin of pomegranate-pistachio (PP), in different levels (0, 10 and 15 % of DM for SBM and 0, 5 and 10% of DM for CM). In second experiment, these supplements were treated by (PP), pomegranate-tea (PT) and sole pomegranate (P) at same levels (10% of DM). The effects of these treatments on protein fractioning of treated and untreated SMB and CM was determined by, CNCPS system, in comparison with fish meal (FM) and corn gluten meal (CGM), as a sources of bypass protein. According to results, treated SBM by PP 10% (SBM-PP) and treated CM by PP5% could increase bypass protein fraction in comparison with FM and CGM. So it can be concluded that these treatments, could be used in reminant diet to provide by pass protein, but further research is necessary to investigate in vivo effects of these treatments.

In this research, samples were collected from three Iranian native dogs and three wolves. Whole-genome sequencing for each individual was performed using next-generation sequencing technology. All short reads were aligned to the reference genome using BWA tool. Single-nucleotide polymorphisms (SNPs) and small insertions and deletions (Indels) were detected using the genome analysis toolkit (GATK). Structural variants were predicted using the BreakDancer software. Annotating single-nucleotide polymorphisms and small insertions and deletions was done using SnpEff Software. Nucleotide diversity values in dogs and wolves samples were calculated using VCFtools. In current researche, 12459651 SNPs were detected that 7819789 and 10454994 were for dog and wolf, respectively. Of the total number of Single-nucleotide polymorphisms, 53. 57%, 31. 989% and 0. 811% were located within intergenic, introns and exon regions. The results showed that structural diversity of wolf genome is higher than that in dog.

The purpose of this research was to classify buffaloes from different areas of the two Azari (West and East Azarbayjan and Ardabil provinces) and North (Guilan province) ecotypes using support vector machine method. A total of 258 buffalo were sampled and genotyped using the Axiom Buffalo 90K Genotyping Array at the Parco Technologic Padano lab in Italy. Two metric methods of cross validation and the area under the receiver operating characteristic (AUC) were used to determine the predictive performance of support vector machine (SVM) to classify individuals. The results of cross validation and methods for classifying different regions of the two ecotypes (4 provinces) were 92% and 96%, respectively that showed despite the difficulty of identifying individuals from provinces close to each other, support vector machine (SVM) method shows higher accuracy in assigning animals to their herds. Result of two ecotypes showed accuracy about 96% and 98% which represents the better ability to separate the two ecotypes. Machine learning method provides predictions for classification of each individual which can be efficient in quality control and genetic studies.

In Iran, more than 96. 4 percent of dairy farms (including more than 68. 7 percent of cattle and calf) have a less than 20 heads of animals, and they produce more than two-thirds of milk and most of animal protein. Also, large shares of water, land and labor force resources are used by this production section. Less scientific studies have been focused on this production system despite it's major contribution. The main question is whether the rural dairy farms with traditional production system have a suitable efficiency, and whether they could pass economic and political transformation, survive and continue production? In this study, structure of representative rural dairy farm was defined. Accordingly, representative farm on average contains 6. 05 heads in the stalls area of 201. 16 m2. Through estimated the social cost of inputs and products, indicators of Domestic Resource Cost, DRC, Social Cost-Benefit, SCB, and Net Social Profit, NSP, had been calculated 1. 85, 1. 086, and 19, 425, 790 IRR per year, respectively, which indicate the lack of comparative advantage of this production system. Analysis of the results revealed that the small scale of the activities that cause excessive use of non-tradable inputs per unit livestock, as well as low production of each livestock per inputs used, are the main reasons of lack of comparative advantage of this production system in Zanjan Province.

Insulin-like growth factor-1 gene (IGF1) is a biological candidate gene for investigation traits such as growth, body weight and muscles growth in different species. In this research eight pairs of white and wild quails were crossed reciprocally as a base population. A total of 34 quails were produced in first generation (F1) and 422 quails were generated by intercrossing the F1 population. Body weights at the time of hatching and different weeks were recorded in the second generation. The association between IGF1 promoter region polymorphism and body weight in different ages was investigated in F2 generation. Using PCR-SSCP assay and sequencing, a novel single nucleotide polymorphism (SNP) was identified in IGF1 promoter region in 472 birds from three Generations. Genotypic frequencies of AA, AG and GG genotypes were 0. 05, 0. 62 and 0. 33, respectively for all generations. The frequency of A and G alleles were 0. 36 and 0. 64, respectively. The AA genotype was lower than AG and GG genotypes for body weights in ages of one to five weeks and slaughter time and the average of daily gain was also lower from week first to four but these differences weren’ t significant. The average of daily gain was higher in females compared to males for AG genotype (P<0. 001). Comparison between detected allele in the present study with reported allele by other research groups in chickens revealed a novel SNP in promoter of IGF1 gene in Japanese quail, but association between this polymorphism with body weight and growth rate were not significant.

In this research to evaluate the effects of probiotic on the growth and some serum biochemical parameters of growing native kid’ s, 24 kid’ s, with 19. 2± 0. 7 kg body weight and 120± 10 days of age were used in a completely randomized design with four treatments and six repeats. These four groups included: 1-The control group was fed on a basal diet (without probiotic or yeast). 2-The second group received basal diet plus one g/day protexin for each kid. 3-The third group was fed on basal diet and two g/day Levocil SC2 yeast, for each kid and 4-The fourth group was fed on basal diet plus one g/day of Levocil SC2 yeast and a half g/day of protexin for each kid. After 14 days adaptation to experimental pens, the kids had free access to experimental diets among 74 days. Daily dry matter intake (DMI), and animal weight changes were recorded. Blood samples were collected from kids. According to the result, there were nonsignificant differences in treatments concerning, DMI daily gain and feed conversion ratio (P>0. 05). Also concentration of some blood parameters such as blood urea nitrogen, total protein, globulin were not affected by probiotics (P>0. 05). Glucose, albumin, triglyceride and cholesterol concentration of kid’ s serum in group 2 (protexin treatment) were higher than other groups (P<0. 05).

The aim of this study was to consider reproductive performance parameters and blood progesterone concentration changes in high-producing dairy cows (39± 2 kg per day) after artificial insemination, in summer and winter. 270 heads of Holstein dairy cattle were choose in three big dairy farms, and blood samples were collected at days seven, ten and fourteen after artificial insemination. Temperaturehumidity index was calculated according to one proposed formula (Dikmen and Hansen, 2009). The results showed that the maximum temperature– humidity index (THI) was 77. 35 and 57. 47 in summer and winter respectively. Pregnancy rates in cows inseminated during the winter months was significantly higher (p<0. 01) than cows inseminated during the summer, and the effects of lactation on conception rate was significant in both seasons (p<0. 01). Open days (101. 18 vs. 165. 07) and number of services per conception (2. 05 vs. 3/48) in the winter were significantly lower than cows inseminated during the summer (p<0. 01). In day 14 after insemination, blood serum progesterone concentration in cows inseminated in the winter was significantly higher (p<0. 01) than summer. Results of this study showed that summer heat stress has significantly affects reproductive performance of dairy cows in central of Iran.