Iranian Journal of Animal Science
Year:2019 | Volume:50 | Issue:2|Papers Count:8

In order to detect signature of selection on buffalo genome, a set of 287 water buffalo samples from 260 Azari and 27 Mazandarani buffalo breeds were genotyped using the Axiom® Buffalo Genotyping 90K Array. The unbiased fixation index method (FST) was used to detect signatures of selection. In total, 14 regions with outlier FST values (0. 1%) were identified. Annotation of these regions using the UMD3. 1 Bos taurus Genome Assembly was performed to find putative candidate genes and QTLs within the selected and 105 genes and 28 QTLs with selection signatures were detected. A high proportion of identified genes (N=27) in regions under selection were involved in olfactory receptor, also some of the detected genes were associated with growth and body development, metabolic and apoptosis possesses, immune system development, and mammary gland development. Some of the identified QTLs in regions under selection were associated with growth traits such as body weight at birth, weaning and mature, subcutaneous fat, meat yield and carcass weight. The detected QTL for milk traits were only associated with milk contents and somatic cell count. However, it is recommended to carry out association studies to show the actual function of these genes.

The aim of this study was to investigate the gene expression profile and find the important genes in the differentiation and evolution of the queen, worker and drone honey bee at Stage 5 Larvae. Therefore, transcripts (total mRNA sequence) of 15 samples of Italian honey bee (A. m. ligustica) including 5 drone, 5 worker and 5 queen bees were aligned to the reference genome of the honey bee. In gene expression analysis of RNA-Seq data, 15962 genes and 31297 isoforms were identified. In our differential gene expression analyses, 465 genes between drone and queen bees, 495 genes between worker and queen bees and 764 genes between drone and worker bees, were expressed differently (P <0. 000005). The largest difference in expression of genes was observed between drone and workers were for GB45614 and GB42053, with log2 fold change that was-10 and 11. 5, respectively. In drone and queen bees comparison, GB45614 and GB48020 genes with log2 fold change 7. 11 and 8. 11, and in queen and worker bees comparison, GB43508 and GB42053 with log2 fold change 6. 6 and-9, had the largest difference in gene expression, respectively. The analysis of the gene ontology (GO) and the pathways involved showed that the function of many of these genes has yet to be found. However, a large number of the genes expressed defiantly in drone and queen bees were related to integral component of membrane, calcium ion binding, carboxypeptidase, cholecystokinin receptor, chitin metabolic process, chymotrypsin inhibitor, haemolymph juvenile hormone binding and pupal cuticle protein, while differentially expressed genes in queen and worker bees comparison were related to metabolic pathways, enzymes metabolism, Pyrimidine metabolism, lipid metabolism, protein kinase, ATP binding and nucleic acid, intracellular cholesterol transport, chitin metabolic process, nitrogen compound metabolic process, hydrolase activity and chitin binding. The genes expressed at different levels in worker bees and drones were related to structural elements, the metabolism membrane and transfer of amino acids, calcium-ion-bound, ion-binder, intracellular cholesterol transport and chitin metabolism.

The purpose of this study was investigated the genetic gain, increase of average inbreeding and accuracy of prediction using simulated data under different mating designs. Two level of heritability (0. 1 and 0. 5) and five maing designs including random mating (rnd), mating based on minimum inbreeding (minf), mating based on maximum inbreeding (maxf), positive assortative mating design based on phenotype (phen) and positive assortative mating design based on estimated breeding value (ebv) were considered. The genetic gain after ten generation in rnd, minf, maxf, phen and ebv mating designs for heritability 0. 1 were 0. 836, 0. 747, 0. 952, 0. 877 and 1. 023 units, respectively, and for heritability 0. 3 were 2. 979, 2. 997, 3. 016, 3. 303 and 3. 595 units, respectively. After ten generation increase of average inbreeding for heritability 0. 1 was 0. 084 in rnd, 0. 038 in minf, 0. 353 in maxf, 0. 079 in phen and 0. 215 in ebv, and for heritability 0. 3 was 0. 057 in rnd, 0. 026 in minf, 0. 356 in maxf, 0. 092 in phen and 0. 177 in ebv, respectively. The results shoewd that the genetic gain in minf design was greater than others mating designs per 1% increase of inbreeding, and minf design was better than other mating designs.

The aim of this study was to investigate the effect of mineral supplementation and chelates of trace elements on production, milk composition and blood parameters of lactating Holstein cows. Lactating Holstein cows (n=24) were randomly assigned to one of the following four treatments; 1) the basic diet include inorganic trace minerals (C), 2) 55 mg of iron, 125 mg of copper, 360 mg of zinc, 3. 5 mg of chromium, 200 mg of manganese, 2 mg of selenium and 12 mg of cobalt with daily feeding of 7 g of Bonzaplex7 chelated mineral supplement (B), 3) the same amount of zinc, manganese, copper and cobalt was supplied with 7 gr of organic trace mineral supplement Availa4 (A), 4) feeding 7 gr of Availa 4 plus 3. 5 gr of Availa-Cr, 2 gr of Availa-Se, 1gr of Availa-Fe (A+3). This study lasted 35 days. Daily feed intake and milk production (3X) were recorded. In spite of more numerical increase in milk yield in treatment B, no effect was observed on the production of milk, milk composition, dry matter intake and rumen metabolites. Plasma glucose concentration in treatments tended to decrease (P=0. 07). Plasma triglyceride concentration decreased significantly in treatments (A), (B), (A+3) compared to group (C), present results could be related to increase bioavailability of trace minerals in chelated form specially chromium and copper in present study.

In order to study the effect of manganese sources in the form of sulphate, hydroxychloride and methionine-chelated manganese organic complex on egg quality of aged laying hens, an experiment was conducted using 384 Hy-line W36 laying hens at 65 week of age for 8 weeks in completely randomized design with 6 treatments, 4 replications and 16 hens in each replication. The experimental treatments included control (with no Mn supplementation), control plus 50, 70 and 90 mg of Mn as hydroxychloride per kg of diet, control plus 70 mg of manganese as manganesemethionine organic complex per kg of diet and 70 mg of manganese as manganese sulphate per kg of diet. The results showed that the different manganese sources had no significant effect on body weight, feed intake, egg production rate, yolk index, specific gravity and Haugh unit of egg. All treatments had better feed conversion ratio in weeks 6, 8 and in the entire experimental period when compared to control group (P<0. 05). All treatments increased egg weight at 8 th week and entire experimental period and eggshell thickness, eggshell percentage and eggshell breaking strength during different weeks of experiment when compared to control group (P<0. 05). The increase in eggshell strength with 90 mg/kg of manganese hydroxychloride in comparison to 70 mg/kg of manganese sulphate was significant (P<0. 05), however no significant difference was observed between 50 mg/kg manganese hydroxychloride and 70 mg/kg manganese-methionine organic complex. The use of manganese organic source or manganese hydroxychloride increased blood and tibia manganese concentrations (P<0. 05) in comparison to control group. Generally, the results showed that 50 mg/kg of manganese hydroxychloride can be replaced for 70 mg/kg of manganese-methionine organic complex or manganese sulphate in the diet of aged laying hens.

This study was designed to evaluate the impact of behavior of workers on production performance of Holstein cows. A number of 48 Holstein milky cows were used in this study. At first two groups, including four workers, were asked to treat cows based on pre-research training. The first group, was asked to behavior common, however second group was asked to behavior kindly and positively. During the experiment, behaviors of all livestock and workers were recorded and evaluated using video imagery and amount of cortisol concentration and produced milk were recorded. The study lasted for 5 weeks and in the end of experiment the results were as follows: livestock that were treated kindly produce significantly higher milk, 4. 86% (p˂ 0. 05), than the control group. Cortisol concentrations also differed significantly between the two groups (p˂ 0. 05), which showed decreased stress in the organs that were treated positively. The positive behavior cause significant decrease in cortisol concentrations in milky cows, which in turn causes decreased stress in milking cows.

An experiment was undertaken to determine the optimum level of corn germ (high-oil content) in broilers diet. This experiment was conducted in a completely randomized design with 5 experimental groups, 5 replicates and 30 birds per each experimental unit from 15 to 42 days of age. Experimental groups were included birds received levels of zero (control), 5, 10, 15 and 20 percentage of corn germ in diet. During the experiment performance traits, productive index, feed cost per kilogram of live body weight, humoral immune responses and intestinal histomorphology were evaluated. To determine the optimum level of corn germ in diet, technique for order preference by similarity to ideal solution (TOPSIS) and maximizing economic profit method were applied. According to the results, optimum level of dietary corn germ inclusion based on TOPSIS and economic methods were 6. 59 and 6. 98 percent, respectively.

The aim of this study was to investigate the effects of levels of concentrate and duration of fattening period in lambs on in vitro gas production (GP), fermentation parameters, protozoa number, and volatile fatty acid (VFA) concentration. Twentyseven Lori male lambs (26± 5 kg BW) were fed with three experimental diets (55, 70 and 85% concentrate) for 100 days (9 lambs for each). At 70 and 100 days of fattening period, ruminal fluids from lambs in each group were collected by the esophagus tube. The mixed ruminal fluids were used for In vitro GP test. Results showed that potential (b) and rate (c) of GP were affected neither by level of concentrate nor by duration of consumption of diets (P>0. 05). Organic matter digestibility of diets increased (P<0. 05) by increasing concentrate level; however it was decreased (P<0. 05) by duration of fattening period. The NH3-N concentration increased (P<0. 05) by increasing the concentration level and duration of the fattening period of the diets. Number of protozoa and total VFA concentration in diet containing 85% concentrate was higher (P<0. 05) than those with 55 and 75% concentrate. With the extension of fattening period, propionic acid, and iso-butyric acid decreased (P<0. 05), while the acetic acid, iso-valeric acid decreased (P<0. 05). Interaction effects of concentrate level and duration of fattening on GP after 24 h of incubation, propionic acid, and butyric acid were observed (P<0. 05) In conclusion, reducing the fattening period when lambs fed a high concentrate diet may exert beneficial effects on rumen fermentation parameters.