فهرست مطالب

  • Volume:6 Issue:2, 2018
  • تاریخ انتشار: 1397/08/13
  • تعداد عناوین: 8
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  • Z. Mehdipour *, M. Afsharmanesh Pages 1-8
    This study was conducted to evaluate the effects of dietary supplementation with cinnamon powder, cinnamon oil, and synbiotic as growth promoter agents on growth performance, blood parameters, and intestinal microbial populations in Japanese quails. A total of 420 one-day-old Japanese quails were randomly assigned to 7 treatments with 4 replicates. The dietary treatments consisted of the basal diet as control, 200 mg virginiamycin/kg, 100 and 200 mg cinnamon oil, 1 and 2 g cinnamon powder/kg, and 500 mg synbiotic/kg added to the basal diet. Birds were given feed and water ad libitum. Body weight gain and feed intake of quails were determined at day 1, 21, and 35, and feed conversion ratio was calculated. At day 35, two birds per replicate were slaughtered for determination of bacteria colony count. Compared to control and 1 g cinnamon powder/kg diet, supplementing 200 mg cinnamon oil/kg increased body weight gain of quails at day 35 (P<0.05). Feeding 200 mg cinnamon oil/kg and virginiamycin improved feed conversion ratio compared to control group at day 35 (P<0.05). Count of lactobacillus bacteria increased in birds fed 200 mg cinnamon oil/kg diet in comparison with the birds fed control, virginiamycin and 2 g cinnamon powder/kg diets. Dietary supplementation of 200 mg cinnamon oil/kg diet and virginiamycin decreased the number of coliforms in the ileum. In conclusion, 200 mg cinnamon oil/kg diet can be applied as an alternative to antibiotic for Japanese quails diets to improve growth performance, and it can also increase the number of lactobacillus bacteria and decrease coliforms.
    Keywords: cinnamon powder, cinnamon oil, Japanese quail, synbiotic
  • M. R. Nilieh, M. Kazemi, Bonchenari *, M. Mirzaei, M. Khodaei, Motlagh Pages 9-19
    The present study was conducted to evaluate the effects of physical form of starter and alfalfa hay (AH) provision on growth performance, ruminal fermentation, and blood metabolites of Holstein dairy calves. Forty-four 3d-old Holstein dairy calves with a mean starting BW of 39.9 ± 1.1 kg were used in a 2 × 2 factorial arrangement. The factors were dietary forage level (0 or 150 g kg-1 AH; DM basis) and physical form of starter feed (coarsely mashed vs. pelleted). Individually housed calves were randomly assigned to 4 treatments: 1) a coarsely mashed starter feed without AH provision (MS-NAH), 2) a coarsely mashed starter feed with AH provision (MS-AH), 3) a pelleted starter feed without AH provision (PS-NAH), and 4) a pelleted starter feed with AH provision (PS-AH). The calves were weaned on d 60 and remained in the study until d 70. The results showed that feeding pelleted starter decreased starter intake significantly compared with coarsely mashed groups during the post-weaning (P < 0.01) and the entire period (P = 0.026).The interaction between AH inclusion and physical form of starter feed tended to be significant for both average daily gain (P = 0.092) and feed efficiency (P = 0.086). Inclusion of AH in the starter feeds increased rumination time and body barrel in calves. Blood urea nitrogen concentration in calves fed AH increased during post-weaning stage. Blood aspartate aminotransferase concentration was greater in calves fed PS form than those fed MS form. Although AH inclusion prevented rumen pH reduction during the pre-weaning period in calves fed PS form; ruminal pH decreased in PS groups in comparison with coarsely mashed groups during the post-weaning period. The pelleted form of starter increased total short chain fatty acids and butyric acid concentrations. However, coarsely mashed form and AH supplementation increased acetate concentration in the ruminal fluid. Overall, the results indicated that coarsely mashed form of starter could be recommended for Holstein dairy calves. Furthermore, AH inclusion in the starter diet may ameliorate the negative effects when pelleted starter is fed to dairy calves.
    Keywords: diary calf nutrition, feed efficiency, starter processing
  • M. M. Sharifi Hosseini *, N. Torbatinejad, T. Ghoorchi, S. Hassani, A. Teimouri Yansari, R. Tahmasbi Pages 21-32
    An experiment was carried out to determine the effect of corn silage particle size and fat supplements on performance, solid passage rate through the digestive tract, and chewing behavior in dairy cows. The forages were coarse or fine corn silage with geometric means of 8.8±2.7 and 5.6±2.8 mm, and alfalfa with geometrics means of 7.0±3.3 mm, and fat supplements were neutral fat (palm) and soy-oil. Diets were: 1) coarse corn silage and four percent neutral fat supplement, 2) coarse corn silage and four percent soy-oil supplement, 3) fine corn silage and four percent neutral fat supplement, and 4) fine corn silage and four percent soy-oil supplement. The forage to concentrate ratio was 43:57 percent in all diets. A 2×2 factorial balanced change-over design experiment with two replicates was used. Physically effective factor (pef) was affected by corn silage particles size and was higher in coarse corn silage diets, but diets Xgm was not affected by silage particles size. Intake of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), and non-fibrous carbohydrates (NFC) was not affected by corn silage particles size, fat supplement, and their interactions. However, physically effective NDF (peNDF) intake was significantly higher (P<0.0107) in coarse corn silage diets. Digestibility of DM, OM, EE, NDF, and ADF was significantly higher in fine corn silage diets but not affected by fat supplements. Duration of chewing activity was longer in coarse corn silage diets (P<0.05). Rumination activities per kg of DM, OM and NDF were longer in coarse corn silage diets. Ruminal solid retention time was longer in coarse corn silage and soy-oil diets (P<0.05). Fat yield, total milk solids, and 3.5% fat- corrected milk yield (3.5%FCM) were the highest in the fine corn silage and neutral fat diets. Protein and 3.5% fat-corrected milk efficiencies were higher in diets containing neutral fat supplement. Inert fat supplement can increase energy density of the diets, thus resulting in improved cow performance.
    Keywords: fat-corrected milk, non-fibrous carbohydrate, physically effective NDF, soy-oil, total milk solids
  • H. Abdi, Benemar *, B. khalili, M. J. Zamiri, H. Ezazi Pages 33-39
    The aim of the present study was to determine seasonal variations in semen characteristics, testicular size, and plasma testosterone concentration in Iranian Khalkhali goats. An artificial vagina was used to collect semen from 10 bucks (2–4 years of age), from November 2013 to October 2014. Testicular circumference was higher (P<0.05) from September to October. Ejaculate volume, sperm concentration, and percentage of normal sperm were higher (P<0.05) during September and October and lower during December and January (P<0.05). Plasma testosterone concentration was higher during October (P<0.05) than other months. Testicular circumference was positively correlated with serum testosterone concentration, percentage of live and normal sperm and semen volume. The lowest level of lactate dehydrogenase (LDH) in the seminal fluid (1.92 U per mL) was recorded during early October (autumn) and the highest level in early spring (2.80 U per mL). The lowest levels of K+ and Na+ in the seminal fluid were recorded in spring (59 and 72.3 mg per dL, respectively). The correlation coefficients of live and normal sperm percentage and sperm motility with seminal fluid K+ level (r = 0.60 and 0.46, respectively) and Na+ level (r = 0.48 and 0.35, respectively) were positive, and with LDH (r = -0.50 and -0.42, respectively) were negative (P<0.01). Despite monthly variations, semen quality was within the range regarded as satisfactory for normal fertility; however, the highest quality semen was collected during September and October.
    Keywords: Khalkhali goats, semen, testicular circumference, testosterone
  • M. Razmkabir * Pages 41-46
    Sex-sorted semen can increase the profitability of dairy cattle by producing offspring of the desired sex. The objective of the present study was to compare conception rate, stillbirth, calving difficulty and sex ratios from sexed and conventional semen in a commercial dairy herd in Isfahan province, Iran. Data were collected from April 2009 until December 2015 on 13,343 inseminations in 8,011 nulliparous Holstein heifers. Based on the proportion of female calves, purity of the sexed sperm was 86.45%, indicating that sexed semen technology was effective in producing heifers. However, sex ratio at birth from conventional semen was 49.05% female. Empirical conception rate in heifers was 42.65% for sexed and 54.85% for conventional semen (P < 0.05). Based on the obtained results, approximately 77.75% of conception rates in heifers were compromised by the sperm sorting procedure. No significant difference was observed for stillbirth due to sexed vs. conventional semen (P > 0.05). The results showed that the higher percentage of female calves in the sexed semen heifers was accompanied by lower risk of dystocia. Despite the higher cost and reduced conception arte, sexed semen can be recommended for insemination of heifers as its use is associated with lower rate of dystocia and birth of more heifer calves.
    Keywords: pregnancy rate, stillbirth, calving difficulty, sex ratio, sexed semen
  • A. Rashidi *, M. Almasi, M. Sattaei Mokhtari Pages 47-56
    The present study was performed to study the effect of inbreeding on the pre-weaning growth traits including the birth weight (BW), weaning weight (WW), average daily gain (ADG), Kleiber ratio (KR) and lamb survival from birth to weaning (SUR) in Baluchi, Iran-Black and Zandi sheep. Significant positive inbreeding trends were found only for Baluchi and Iran-Black breeds as 0.038 and 0.278, respectively. Inbreeding depression was assessed by fitting individual inbreeding coefficient as a linear covariate for each trait applying the most suitable animal model detected via Akaike's Information Criterion (AIC) among the models containing different combinations of direct additive and maternal effects. Inbreeding had no significant effect on BW in these breeds (P>0.05) but WW decreased significantly through inbreeding as -29.35 g, -25.12 g and -42.20 g per 1% increasing in inbreeding for Baluchi, Iran-Black and Zandi breeds, respectively. The influence of inbreeding on ADG of Iran-Black and Zandi breeds was significant, the corresponding values of -0.30 g/day (P0.05). Inbreeding significantly influenced KR in Baluchi (0.30) and Zandi (-0.13) breeds but not in Iran-Black breed (P>0.05). Inbreeding (P0.05). Inbreeding depression was observed for most of the pre-weaning studied growth traits (except for BW) and lamb survival from birth to weaning in these breeds. It was concluded that the mating policies designed to minimize the inbreeding effect in Baluchi and Iran-Black sheep have not been effective.
    Keywords: inbreeding depression, inbreeding coefficient, lamb survival, sheep
  • F. Ghafouri, Kesbi * Pages 57-66
    The aim of this study was to model the variances and covariances of body weight in Zandi sheep from 60 to 365 days of age using random regression models (RRM). Legendre polynomials of different orders were used to model the direct and maternal covariances. Mean trends were also modeled through a quadratic regression on orthogonal polynomials of age. Homogeneity and heterogeneity of the residual variance were considered along the growth trajectory. Different models were compared by log-likelihood ratio test (LRT) and Akaike’s information criterion (AIC). Results showed that simple repeatability model in which orders of 1 were used for all random effects could not adequately model variations in growth curve of Zandi lambs. A RRM with Legendre polynomials of orders 3, 3, 3, and 3 for direct additive genetic, individual permanent environment, maternal additive genetic and maternal permanent environmental effects was selected as the most parsimonious model. The power of the parsimonious model decreased when maternal effects were excluded from the analysis, indicating the necessity of including maternal effects in the model for genetic evaluation of Zandi lambs. Considering the heterogeneity of residual variance along with the growth trajectory improved the overall properties of the model. Direct heritability (h2) decreased from 0.3 at 60 days of age to 0.15 at about 120 days and then increased with age gradually and reached 0.39 at 365 days of age. The individual permanent environmental effect (p2) decreased from 0.43 at 60 days of age to 0.23 at 180 days of age and fixed between 0.25 and 0.30 thereafter. Maternal heritability (m2) was 0.03 at 60 days of age, increased to a peak around 240 days of age (0.22) and decreased with age thereafter. The ratio of maternal permanent environmental variance to phenotypic variance (c2) was below 0.03 throughout the trajectory. Estimates of coefficients of variation (CV) revealed the presence of considerable genetic and environmental variability in growth curve of Zandi sheep which can be exploited for breeding purposes. Both direct and maternal correlations were positively high between adjacent weighs but decreased as the distance between ages increased.
    Keywords: sheep, body weight, random regression models, heritability, genetic correlation
  • M. Hatami, Z. Ansari Pirsaraei *, A. Akhlaghi, H. Deldar Pages 67-72
    Avian sperm are stored in the sperm storage tubules (SSTs) of the hen oviduct for a prolonged period. The impact of avidin-related protein-2 (AVRP2) and carbonic anhydrase II (CA II) in sperm viability in the SSTs has been suggested. The aim of the present study was to investigate the effect of oral administration of a high dose of thyroxine on the oviductal expression of AVRP2 and CA II genes in broiler breeder hens. The birds (n=70), housed in separate cages, were randomly allotted to two treatment groups to either zero (CON) or 0.30 mg thyroxine per day (T4 group) for 12 weeks. Feed and water were supplied according to the Cobb 500 standards (metabolizable energy: 2700 kcal/kg and crude protein: 14%). Blood samples were prepared seven times for determination of plasma triiodothyronine (T3) and T4 concentration. At the end of the treatment period, 20 hens were randomly selected and killed to determine the expression of AVRP2 and CA II in the SSTs using the real-time PCR procedures. Expressions of AVRP2 and CA II genes were influenced by T4 treatment where an increased expression of CA II was recorded for T4-exposed hens (P<0.05). However, expression of AVRP2 was not significantly different between the treatment groups (P>0.05).
    Keywords: avidin-related protein-2, breeder hen, carbonic anhydrase, oviduct, thyroxine