Iranian Journal of Animal Science
Year:2017 | Volume:48 | Issue:3 |Papers Count:13

The aim of this research was to determine effects of different levels of all-trans-retinol acetate on immunity performance of broiler breeder roosters and also to find the level with most immunity performance. * Treatments were consisted of 5 level all-trans-retinol acetate (0, 6000, 12000, 18000, 24000 IU/kg) added to basal diet. * 60 broiler breeder roosters were used from 45 to 48 weeks of their rearing period in a completely randomized design with 12 replicates per treatment. * Cell immune system response was measured by PHA-P sensitivity and blood immunity was measured by antibody titr against SRBC. * Titr of antibody against SRBC was affected by retinol acetate level (P<0.05) and blood immunity repose was increased by increasing level of retinol acetate. * Highest and lowest blood immune responses belong to 24000 and zero IU/kg treatments respectively (P£0.03). * Increasing level of retinol acetate increased IgM (P£0.04). * The results of cutaneous sensitively showed increasing effect of retinol acetate till 18000 IU/kg (P<0.05). * The results of this research showed that 18000 Iu/kg of retinol acetate resulted in best level of immune system in broiler breeder roosters, and this amount is higher than suggested amount by ROSS 308 catalogue.

This exprement was conducted to compare the effects of antibiotic and some Iranian and similar imported probiotics on performance, economic indicators and intestine morphology of broilers.540 1-day old broilers were used in a completly randomized design with 6 treatments and 5 riplicates per treatment. Pedi-Guard and Lacto-Feed were used as Iranian and Bactocell and Primalac probiotics as imported products. Treatments were: 1) basal diet (control) and basal diet with: 2) antibiotic, 3) Bactocell probiotic, 4) Pedi-Guard probiotic, 5) Primalac probiotic and 6) Lacto-Feed probiotic. Orthogonal contrasts were used to compare the effect of probiotics versus control and antibiotic, Iranian probiotics versus imported products and single strain probiotics versus multi strains. Primalac decreased feed intake and body weight gain, while antibiotic and Bactocell increased the feed intake and body weight gain in the starter period (P<0.05). These changes did not change the feed conversion ratio. Economic indices, production efficiency factor and body weight did not show any significant differences. Antibiotic reduced villus height, surface area and the crypt depth and the Primalac showed an increase in villus height and surface area in the jejunum (P<0.05). Contrast of antibiotic versus probiotics resulted in improvement in performance, gross profit, as well as decrease in jejunum length, crypt depth, villus height, and surface area (P<0.05). Reduction in crypt depth in ileum was the only change caused by using Iranian probiotics versus imported products (P<0.05). As general conclusion, Iranian probiotics, imported probiotics and antibiotic were not different from control group when judge based on performance and economic indexes.

In this research genetic variation using 6 microsatellite loci (HMS07, HMS03, HMS02, HMS06, ASB02, ASB23) was studied in Iranian Kurdish horse population. Whole blood samples were randomly collected from 52 horses in Kurdistan, Kermanshah, Elam, Western Azerbaijan, Esfahan, Kerman and Hamadan regions. DNA was extracted from blood samples. Polymerase chain reaction (PCR) was used for amplification of 6 microsatellite loci using pairs of standard specific primers. Then, the PCR products assessed with 8% silver-staining acrylamide gel and electrophoresed. All microsatellites loci were polymorphic. The number of alleles observed and expected hetrozygosities were calculated with Shannon Index. The largest and smallest number of alleles were observed in HMS07 locus (10 alleles) and HMS02 (4 alleles) respectively. Our results confirmed the high efficiency of microsatellite markers for assessing population structure in Iranian native horses.

Identification of disease-causing genes that underlie complex traits such as susceptibility to disease not only can improve diagnosis and the prevention of illness, but also help breeder to select resistance animals against diseases. In the current study to aim the higher power of statistical analysis to identification of genes and biological pathways related to mastitis disease, we used Fisher meta-analysis to combinep-value s obtained from individual analysis of datasets extracted from 6 microarray-based studies which investigate transcriptomic data of mammary gland tissue infected by Escherichia coli (E. coli) in dairy cows. Identification of genes that did not show a significant p-value in any of the independent studies may confirm the aim and lead to introduce a more complete set of biological pathways involved in this disease such as the pathways related to immune response, inflammation, proteolysis, growth, and death of cell.Positive regulation of transcription from RNA polymerase II promoter, is new pathways related to this disease which despite of the enrichment by maximum number of up-regulated genes in this study, have not been reported in previous mastitis studies.

Three Non-lactating Holstein cows equipped with ruminal cannulas were used to determine the impact of different methods of treating soybean meal (SBM) on the ruminal degradability and intestinal digestibility of crude protein and amino acids (AA). Solvent-extracted SBM (Control), Meal processed by adding 25% (w/w) water and heated at 150oC for 30 minutes (treatment 2), Meal heated at 150oC for 30 minutes (treatment 3), and meal melted xylose by adding 3 moles per mole of lysine and heated at 150oC for 30 minutes (treatment 4), were incubated in the rumen in nylon bags for 0, 2, 4, 8, 16, 24, and 48 h according to National Research Council (2001) guidelines. Processing of SBM caused to decrese, incresea and decrese of rapidly degradable CP fraction, slowly degradable CP fraction and the constant degradation rate of crude protein, respectively (P<0.05). There was a significant differences between treatment on the ruminal disappearance of amino acids except were for threonine and glycine (P<0.05). Intestinal disappearance of crude protein had no difference between treatments. However, the rate of disappearance of essential amino acids except threonine was different between treatments (P<0.05). Processing with xylose improved bioavailability of the lysine (P<0.05). Results had shown that there were differences between RUP amino acid profile of original SBM and processed products.

The aim of this research was to investigate the expression of trypsin gene in the pancreas tissue of broiler chicken fed tannin containing oak diets. In this experiment, three diets (control, 15% and 20% oak) were fed to broilers from 1 to 42 days of age. On days 21 and 42, total RNA extracted from pancreatic tissue of 36 broiler chicken (18 for each time, 6 for each treatment). To study of gene expression, the trypsin expression was compared with b-actin gene as a reference gene. Data of gene expression analzed, using REST, V2.0.13 2009 software. No significant association was found between pancreases relative weight and different treatments on day 21, but the relative weight of pancreases on day 42 was significantly for increased in diet with 20 percent of oak acorn in comparison to other treatments. The mRNA expression level of trypsin gene was significantly higher in 20 percent of oak acorn treatment on day 21, but their differences were not significant in compared to control diet on day 42. In addition, significant correlation was found between gene expression of trypsin and relative weight of pancreases on day 42.

The aim of this research was to estimate genetic parameters for mean and residual of body weight in Japanese quail. A total of 2629 quail body weight records at 28 days old were used in this research. Double hierarchical generalized linear model (DHGLM) was used to estimate (co) variance components using ASREML 4.0 software. Additive genetic variance for mean and residual were 189.59 and 0.18, respectively and were statistically significant (p<0.01). The genetic standard deviation for residual of body weight was 0.42. Therefore decreasing estimated breeding value of residual by 1 genetic standard deviation can increase the uniformity of body weight at 28 days old by 42%. Heritability for mean (0.51) was larger than the heritability for the residual (0.02). Although heritability for residual was low but it was significant (p<0.01). The Spearman rank correlation between estimated breeding values in mean and dispersion was low (0.094). Low and unfavorable genetic correlation (0.09) was obtained between mean and residual. The results obtained in this research show the residual of body weight records at 28 days old is under control of additive genetic variance and uniformity can be achieved by means of genetic selection.

To investigate the effects of tylosin injection in dairy cows at dry period on performance, milk composition and some blood parameters in subsequent lactation, 120 Holstein cows with a mean weight of 720±20Kg were used. Treatments were no tylosin (treatment 1; control group), injected 0.025 (treatment 2 low tylosin; LT) and 0.05 (treatment 3 high tylosin; HT) ml tylosin 20% per kg of body weight per day for 3 days after drying days. To determine biochemical parameters blood samples were collected at the drying day and 0, 7, 14, and 21 of lactation. Data of milk production and composition were collected for 4 months after calving. The difference between serum total protein concentration between treatments tended to be significant (P=0.051). Aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities were lower in the control group (P<0.05). The activity of creatine kinase (CK) tended to be significant (P=0.053) with tylosin injection. Milk production, milk protein and fat contents, calving parameters and periparturition disorders did not affect by tylosin injection (P>0.05). The incidence of mastitis in the groups receiving tylosin was significantly lower than the control group (P<0.05). Results suggest that tylosin do not cause dramatic changes in serum clinical chemistry profiles, but it was effective in reducing the occurrence of mastitis and had no negative effect on parturition, disorders around it and calf losses until 2 month of age.

With development of mixed models, lactation model (LM) was replaced with random regression model (RRM).However, the minimum number of required test day (TD) records per animal to replace LM with RRM is a challenge in genetic evaluations. In this study, 381, 236 test day records of 44, 117 first parity dairy cattle which collected by Animal Breeding Center of Iran were used from 2006 to 2016. Based on number of TD records per animal, cows were divided into five groups by restricting cows that presented at least 2, 4, 6, 8 or 10 test day records in the lactation. The rank correlation between predicted breeding values (EBV) for LM and RRM irrespective of number of TD records was relatively moderate (0.44) and the rank correlation between two models using at least 2 TD records was 0.71. When 10 top percent of cows were used for comparison of LM with RRM, the rank correlation decreased to 0.08. The correlation of EBV of cows with³2 TD records with cows with³10 records in RRM was 0.85. The mean of breeding values accuracy in RRM was 4% higher than LM. Overall, use of RRM has advantages over LM and it is suggested to use RRM with at least 2 TD records instead of LM for genetic evaluation of milk yield trait.

The aim of present research was to investigate effects of supplementation lambs’ fattening diet with fennel and cumin powder and Saccharomyces cerevisiae in comparison with monensin onin vitro gas production and fermentation parameters, nutrient digestibility, microbial enzyme activity and protozoa population. Seven experimental diets were 1) control diet (basal diet) and supplementing control diet with 2) 8 g fennel (F) +8 g cumin (C) powder per kg DM (1 to 1 ratio), 3) 12 g F+4 g C (75 to 25 ratio), 4) 5 g yeast per kg diet DM, 5) 5 g yeast+8 g F+8 g C (1 to 1 ratio), 6) 5 g yeast+ 12 g F+4 g C (75 to 25 ratio), and 7) 30 mg monensin per kg diet DM. Diets were incubated in rumen liquor in a completely randomized design. The highest gas production during 24 and 48 h of incubation, total gas production, short chain fatty acids, organic matter digestibility and estimated metabolizable energy were observed in the diet containing yeast along with F and C (75 to 25 ratio) compared to control diet (P<0.05). Diet containing yeast along with the same ratio of F and C resulted in the highest gas production during 72 h of incubation, gas production from the insoluble, but fermentable fractions (b), filter paper degrading andα-amylase activities compared to control diet and diet containing monensin (P< 0.05). The highest total protozoa population (P<0.10) and sub-family of Diplodiniinae (P£0.05) was observed in control diet compared to diet supplemented with yeast along with the 1 to 1 ratio of F and C. In conclusion, we found that cumin and fennel powders along with saccharomyces cerevisiae are promising alternatives to monensin in lambs fattening diets, and that their dietary inclusion improved gas production and nutrients’ degradability by modifying rumen fermentation in vitro.

Designing and implementing temperature-humidity index insurance is a proper risk management tool that can lower animal breeder loss against heat stress and can lead to their income stability. Given this important issue in the present study, this insurance system has been designed for dairy cattle production in Damavand County. The required data were collected monthly from Damavand County’s agricultural and meteorological organizations in a time span ranging between 2012 and 2016. Given the flexibility of copula approach and its high accuracy in measuring dependency structure, this method was employed to account for joint distribution function and to measure expected loss. The results indicated that a strong dependency exists between dairy cow yield and temperature-humidity index, and this dependency can be better explicated through negative rotating Clayton index than any other copulas. The premium amount for each dairy cow has been calculated as 610650 Rials at 100 percent coverage level. Additionally, the expected loss resulted from heat stress at the 100 percent coverage level has been calculated as 42 kilograms within a month for each dairy cow. Considering the total number of dairy cows in the town, i.e.2207 cows, the total loss resulted from heat stress has been calculated as 92694 kilograms and over 1.2 billion Rials within a month. With regard to the great loss resulted from heat stress and the importance of milk in the health of societies, it is recommended that the officials and policy-makers devote a particular attention to designing this insurance system throughout country.

The Arab horse breed is one of the most ancient horse breeds. Arabian horses are famous for endurance riding and flat racing. Moreover, this breed has contributed to the formation of some of the most important horse breeds in the world. Kurdish horses are found in rough terrain and hilly regions and they are suitable for riding in hilly areas and Polo tournament. To investigate the population structure and to find the signatures of selection in the genome of Arabian and Kurdish horses, blood and hair samples from 38 Arabian and 58 Kurdish horses were taken and genotyped using the 670K Axiom Equine Genotyping Array. Principal component analysis (PCA) was carried out on the genotypic data and Fst statistic for each SNP was calculated. Fst values were smoothed over each chromosome. PCA showed that the Arabian horse population is more genetically diverse than the Kurdish horses. We identified six genomic regions showing signatures of selection. The strongest signal of selection was found in ECA8. Annotation of the regions of the genome that showed selection signatures revealed candidate genes e.g. CaMKK2, MLXIP and ATP2A2 that may involve in endurance riding and racing. These genes for further studies are proposed.