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Nutrition during mating is one of the most important factors affecting the reproductive performance of ewes. The aim of this experiment was to investigate the effect of vitamin AD3E injection around mating on body weight (BW), body condition score (BCS), plasma hormones, minerals, metabolites, vitamins, antioxidant enzymes and reproductive performance of Afshari ewes. Eighty-eight Afshari ewes were divided into 2 groups (n=44) based on age (2-4 years), BW (average 40 kg) and BCS (mean 2.75) and assigned randomly to one of the two experimental treatments. Experimental treatments consisted of control (C; no vitamin AD3E injection) and AD3E injection (AD3E) groups. Ewes in AD3E group received 5 mL of vitamin AD3E solution subcutaneously at the beginning of the experiment, the day of CIDR insertion, the day of CIDR removal, and one week after mating. Two weeks after the start of the experiment, the estrous cycles of all ewes were synchronized using intravaginal 12-day CIDRs. The BW, BCS and plasma minerals and metabolites concentrations of ewes did not influence by experimental treatments (P>0.05). Ewes received AD3E had lower estrogen (E2) and progesterone (P4) and higher testosterone concentrations at the day of CIDR removal (P<0.05). The AD3E injection increased plasma vitamin D3 and glutathione peroxidase (GPX) at the day of CIDR removal and at the day of estrous and decreased plasma malondialdehyde (MDA) concentration at the day of CIDR removal (P<0.05). The results obtained indicated that there was no significant difference (P>0.05) between the treatment groups in reproductive outcomes including estrous response, fertility rate, lambing rate, twining rate and lamb sex and birth weight. These results indicated that vitamin AD3E injection around mating improved antioxidant enzyme status but had no significant effect on reproductive performance of Afshari ewes. Further researches are needed to evaluate the effect of different levels of vitamin AD3E injection around mating on reproductive performance of Afshari ewes. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of calcium (Ca) and magnesium (Mg) injection around mating on skewing lamb sex ratio in ewes. Thirty cycling multiparous Kurdish × Romanov ewes were divided into two groups (15 per group) based on age and body weight (BW). Animals were received either 20 mL of solution (CaMg) or 20 mL of sterile water (Control) subcutaneously every 7 days from 28 days preto 7 days post-mating. Each mL of CaMg solution contained 400 mg of Ca borogluconate and 22 mg of Mg hypophosphate, which provided 30.4 mg of Ca and 2.04 mg of Mg. Ewes in CaMg group tended to had lower body condition score (BCD) at the day of controlled internal drug release (CIDR) removal (2.79 vs. 2.69; P=0.09) and its change from beginning of experiment to CIDR removal (0.21 vs. 0.04; P=0.06) than control group. The CaMg injection increased plasma insulin (13.2 vs. 11.33 μIU/mL), Ca (9.13 vs. 8.30 mg/dL), Mg (3.66 vs. 3.33 mg/dL), Na (188.83 vs. 175.73 mEq/L) and glucose (56.94 vs. 50.07) concentrations at the day of CIDR removal and Ca (8.87 vs. 8.03 mg/dL) at the day of estrous and mating compared to control group (P<0.05). Lower estradiol (E2) + testosterone to progesterone (P4) ratio at the day of estrous and mating (102.87 vs. 135.67) was observed in ewes received CaMg injection compared to other group (P<0.05). Injection of CaMg solution had no significant effect on lamb sex ratio (P>0.05), although proportion of female lambs (68.18 vs. 56.52%) was numerically higher in ewes of the CaMg group than control group. These results indicated that there was a potential for skewing the sex ratio of lambs toward females when CaMg solution was injected subcutaneously during mating. [ABSTRACT FROM AUTHOR]

• Five non-linear mathematical models were fitted on body weight-age data of Kordi sheep and were compared applying Akaike's information criterion (AIC), mean square error (MSE) and adjusted coefficient of determination (R2 adj). • The Brody model showed the lowest AIC and MSE and the highest R2 adj among the tested models in all, male and female Kordi lambs. • The estimates of posterior means for heritability of the studied growth curve parameters were low in magnitude. • Estimated mature weight of Kordi male lambs was greater than that of female ones. • Female Kordi lambs had higher maturation rate than male Kordi lambs. In the present study, 43,441 body weight-age records (21,361 records on male lambs and 22,060 records on female lambs) on 6899 lambs descended from 235 sires and 2842 dams that collected from 1991 to 2015 in Kordi sheep breeding station, located in Shirvan city, North Khorasan province, North-eastern area of Iran, were used. Five non-linear models including Brody, Negative exponential, von Bertalanffy, Logistic and Gompertz were fitted on body weight-age data and compared applying Akaike's information criterion (AIC), mean square error (MSE) and adjusted coefficient of determination (R2 adg) for determining the most appropriate model describing the growth curve for all, male and female Kordi lambs. The Brody model showed the lowest AIC and MSE and the highest R2 adg among the tested models for all, male and female Kordi lambs. Therefore, Brody model was selected as the best one for describing growth curve in Kordi sheep. The estimated values for parameters of growth curve under Brody model including parameters A (estimated mature weight), B (an integration constant related to initial animal weight) and K (maturation rate) were 43.372, 0.905 and 0.007, respectively. Parameters of A , B and K were estimated as 48.630, 0.911 and 0.006, respectively for male lambs and 38.444, 0.898 and 0.008 for female lambs, respectively. A nultivariate animal model was considered for genetic analysis of the growth curve parameters via Gibbs sampling under a Bayesian approach with 100,000 iterations, considering the first 20,000 samples as the burn-in period and a thinning interval of 10 samples. Posterior means for heritability estimates of the studied growth curve parameters of Kordi sheep were 0.08, 0.14 and 0.04 for parameters A , B and K , respectively; showed low level of genetic variation for the parameters of growth curve in Kordi sheep. Posterior means for the estimates of genetic correlations among the studied growth curve traits were 0.48 (A - B), -0.22 (A - K) and -0.28 (B - K). The Brody model can be considered for predicting live weight of Kordi lambs at later ages from early body weight data and can help planning farm management practices such as feeding and drug administration (since these practices are commonly focused on live body weight) and also decision making regarding the selecting of highly productive animals by monitoring their growth curve. [ABSTRACT FROM AUTHOR]

Abstract: The objective of the present study was to estimate genetic parameters for post-weaning traits in Kermani sheep. Traits were included 6-month weight (6MW), 9-month weight (9MW), yearling weight (YW), greasy fleece weight at first shearing (GFW) and greasy fleece weights at various shearings (RFW). Data and pedigree information used in this research were collected at Breeding Station of Kermani sheep during 1993–2004. Genetic parameters were estimated with single- and multi-traits analysis using restricted maximum likelihood (REML) procedures, under animal models. Log likelihood ratio test indicated the most appropriate model for 6MW and 9MW should included direct additive genetic effects as well as maternal permanent environmental effects. However the most appropriate model for YW and GFW had only the direct additive genetic effects. The effects of sex, age of dam and year of birth were significant on body weight traits (P <0.01). GFW was influenced significantly by sex and year of birth (P <0.01) but was not affected by age of dam (P >0.05). Type of birth was no significant effect on studied traits (P >0.05). Also, the age of lamb at weighing time was a significant influence on 6MW, 9MW and YW. Direct heritability estimates for 6MW, 9MW, YW and GFW were 0.32, 0.03, 0.15 and 0.15, respectively. Maternal permanent environmental estimates of 0.09 were obtained for 6MW and 9MW. Genetic correlation estimates between mentioned traits ranged from 0.51 to 0.99. Phenotypic correlations were generally lower than those of genetic correlation and varied from 0.05 to 0.79 for various traits. The environmental correlations estimates between GFW with growth traits were low, but between other traits were positive and high, ranged from 0.54 to 0.72. The value of repeatability estimated for greasy fleece weight was 0.22. [Copyright &y& Elsevier]