Animal Production Research
Year:2019 | Volume:7 | Issue:4|Papers Count:8

The objective of this study was to evaluate different animal models in different genomic scenarios to estimate the breeding values and to detect genotype × environment (G × E) interaction. Genomic data were simulated to reflect variations in number of QTL (100 and 500) and linkage disequilibrium (low and high) using 10K SNP panel for 30 chromosomes. On this genome, the trait simulated in three different environments with heritabilities 0. 10, 0. 25 and 0. 50, respectively. In the next phase, low (0. 47) and high (0. 83) genetic correlations were assigned between third environment (h Abstract 2 =0. 50) with first (h 2 =0. 10) and second (h 2 =0. 25) environments. The results indicated that the accuracy of genomic prediction increased with increasing the heritability, linkage disequilibrium and the genetic correlation between the traits. Comparing to single trait animal model, multiple trait animal model increased accuracy of genomic prediction. Accuracies of genomic predictions were generally high when the genomic breeding values of third environment were estimated using information of their relatives in the second environment, and the highest accuracy (0. 422) obtained from the scenario with high linkage disequilibrium and low QTL. Also, accuracies of genomic prediction increased with increasing percentage of animals from 25 to 75. Generally, the level of LD, type of animals in training set, number of phenotypic records in validation set and genetic correlation across environments play important roles if G × E interaction exists. In conclusion, considering the G × E interaction contributes to understanding variations of quantitative trait and increasing accuracy of genomic prediction.

Pedigree analysis is a useful tool for the study of structure, genetic diversity and history of populations. This study was conducted to characterize population structure, estimation of inbreeding and effective population size in Markhoz goats using pedigree analysis. Data consisted of pedigree records of 5726 animals, collected between 1987 and 2016 by Markhoz goat Performance Testing Station. Computer programs, including CFC for descriptive statistics of pedigree, ENDOG for estimation of effective population size and generation interval and EVA for inbreeding trend were used in this research. The ratio of inbred animals was 54. 3% of total population. The mean of co-ancestry and inbreeding coefficients in the population were 2. 61 and 2. 68, respectively, indicated that the observed inbreeding level is higher than expectation. Estimated effective number of founders was 85. 65, represents unequal founder contributions in population. Undesirable trend for inbreeding could be due to high contribution of few ancestors in reproduction and low migration rate of animals in Markhoz goat station. The mean generation interval for total population and founders were 3. 23 and 5. 73 years, respectively, emphasizing the replacement of young bucks and does in the recent generations. Effective population size computed via individual increase in inbreeding was equal to 60. 41 and was not far from the 50, a critical level proposed for an ideal population. The results indicate that the biodiversity of population has decreased. In conclusion this research supports the priority for conservation genetic strategy instead of selection programs in Markhoz goat.

This experiment was carried out to evaluate the effect of four substitution levels of 0, 33, 66 and 100% of dietary calcium carbonate with carbonation mud of sugar beet using pelleted or mash diets on performance and calcium and phosphorus deposition in tibia of broiler chickens. The statistical model of project was a two-factor factorial design in a completely randomized design. The trial lasted 42 days and the chickens had free access to water and feed. The results indicated that means of daily feed intake, daily gain and body weight of pelleted diets compared to mash diets for all the levels of substitution was significant (P<0. 05), and the best feed conversion ratio was belonging to zero substitution level of pelleted diets that was significantly different with other treatments (P<0. 05). Carcass yield, abdominal fat, proventriculus and ceca percentages of pelleted diets were not significantly different with mash diets but Gizzard percentage of pelleted diets was significantly less than mash diets and liver and intestines percentages were significantly more than mash diets (P<0. 05). Ash, calcium and phosphorus percentages of tibia in pelleted diets had not significantly different with mash diets although the 33% substitution level of pelleted diets had the highest phosphorus percentage compared to other treatments (P<0. 05). In general, the results showed that pelleted diets including carbonation mud had better performance than mash diets and did not have significant effect on calcium and phosphorus deposition of tibia in broiler chickens.

A study was conducted to evaluate the effect of adding different levels of ethanol, methanol and their 50: 50 (v/v) binary mixture of propolis extract on in vitro gas production parameters, dry matter and organic matter digestibility, protozoa counts and methane production in a completely randomized design. Crude propolis sample was collected from Ramian region and its extraction was taken by ethanol, methanol and their mixture. Experimental treatments were including: 1) control containing basal diet with forage: concentrate ratio of 50: 50 (without any extract), treatments 2 till 5 (control treatment + 25, 50, 100, 200 µ l levels of ethanol extract, respectively), treatments 6 to 9 (control treatment + levels 25, 50, 100, 200 µ l of methanolic extract, respectively), treatments 10 to 13 (control treatment + 25, 50, 100, 200 µ l levels of binary solvents mixture extract, respectively). Results showed that the highest and lowest potential gas productions were related to treatment containing 200 µ l and 25 µ l of methanolic extract, respectively (P<0. 05). Treatment containing 200 µ l of binary solvents mixture extract had the highest metabolizable energy, organic matter digestibility and short chain fatty acid concentration (P<0. 05). There was significant difference between treatments on dry matter and organic matter digestibility (P<0. 05). Hence, treatments containing 25 and 100 µ l of methanolic extract had the highest and control treatment had the lowest dry matter and organic matter digestibility, respectively (P<0. 05). Using 25 µ l and 200 µ l levels of binary solvents mixture extract reduced Halotrish more than other levels and other extract. However, treatments containing propolis extract reduced methane production remarkably. Generally, it can be concluded that propolis methanolic extract has potential to improve ruminal fermentation efficiency. However, more research is warranted to manipulate rumen microbial fermentation.

The aim of the present study was the determination of chemical composition and nutritive value of carrot pulp (CAP), and then evaluating the effects of its different dietary levels on diet digestibility and in vitro rumen fermentation. At first, chemical composition and nutritive value of CAP were compared with wheat straw (WS) and alfalfa. Then, the effect of substituting different levels of CAP (0, 50, 100, 150 and 200 g/kg dry matter [DM]) for forage portion of the diet on in vitro fermentation parameters was assessed. The highest and lowest volume of gas production after 16 and 24 h of incubation as well as constant rate of gas production (c) were observed with incubation of CAP and WS, respectively. However, the highest volume of gas production and potential of gas production (b) were observed for alfalfa, while the lowest amount was observed with WS treatment. The highest amounts of DM and organic matter disappereance, short chain fatty acids and microbial crude protein (MCP) were observed with CAP incubation, while WS resulted in the lowest amounts. With replacing forage portion of the diet with CAP, up to 200 g/kg DM, with exception of ammnia-N concentration and MCP which decreased and increased linearly, other fermentation parameters did not affect with experimental diets. Present results indicated that CAP has favourable chemical composition and nutritive value, and its incorporation as feedstuff in ruminant nutrition, up to 20% of diet, is suggested. However, more experiments, especially in vivo studies, are needed to confirm the present results.

This research was aimed to evaluate effects of processing on protein and starch degradability parameters of hulled and hull-less barley grain using NorFor system. Two barley cultivar grain treatments, NaOH, Formaldehyde and urea were used at 35, 4 and 35 g/Kg DM, respectively. Using test data derived from the measurement of ruminal degradability of crude protein and starch barlely, the soluble protein (sCP), protein degradation potential (pdCP), fixed rate analysis (kdCP) parameters and starch including soluble starch (sST), starch degradation potential (pdST) and fixed rate analysis were estimated in NorFor system. For measuring ruminal egradability of crude protein, nylon bag method and three rams were used at incubation times 0, 2, 4, 8, 16, 24 and 48 h. The results showed that the hull-less and hulled barley treated with a solution of urea has the highest amount of protein (sCP, 561 and 610 g per kg CP) which had a significant difference with other treatments. The starch solution (sST) in without processing hull-less barley had the highest value which was significantly different from other treatments (P<0. 05). The starch degradation potential was the highest in non-processed barley compared to hull-less barley treatments. In general, the lowest sCP and sST were in Hullless barley+ NaoH and Hulled barley + urea in NorFor system, repectively. This would be important for protein and starch passage from rumen.

The purpose of this study was to investigate the technical efficiency of male calf fattening units in Guilan province and to determine the yield to their scale using the data envelopment analysis method. The cost and income information required was collected by completing the questionnaire using 52 units of fattening in Guilan province. The results showed that the average technical efficiency was 0. 961 and 0. 494 using the variable and constant returns approach to scale, respectively, which showed the efficiency of the production of fattening units. In order to evaluate the factors influencing the technical performance of the fattening units, two components of the equipment and facilities of fattening units and knowledge of fattening knowledge were used. Using the interval of standard deviation from mean (ISDM) method, scores for these two components were categorized into four groups. Then, using ANOVA and paired comparison of the groups determined by the ISDM method with the help of Tukey test, the impact of facilities and equipment privileges and fattening knowledge was studied on the technical efficiency score of fattening units. The results showed that the couples of the four groups of facilities and equipments and fattening knowledge were significantly influenced by the technical efficiency of the units.

Ghrelin is a 28 amino acid peptide hormone that is expressed in the stomach and a range of peripheral tissues. Expression and functional role of ghrelin in the sex accessory glands of mammals have not been studied yet (except for human). This study was aimed to determine the immunohistochemical position of ghrelin in prostate, seminal vesicles and ampulla tissues of Holstein bulls. Anti-ghrelin mouse monoclonal antibody was used as primary antibody and donkey polyclonal antibody Anti-IgG Horseradish Peroxidase (HRP) was used as secondary antibody. Samples of sex accessory glands tissues were collected from five Holstein bulls aged two years old, and preserved in 10% buffered formalin for the immunohistochemical test. Then, paraffin blocks and tissue sections were prepared. The immunohistochemical results were positive for the secretory cells of prostate, seminal vesicles and ampulla. But the intensity of staining in the prostate glands was very weak than to the other glands. According to the results of this research, the expression of ghrelin in some accessory glands of the bull may display its possible role in fertility parameters of sperm and overall fertilization process.