The effect of dietary inclusion of Artemisia sieberi leaves on growth performance, feeding behaviors, ruminal fermentation, feed digestibility, and blood hemato-biochemical profile of growing male lambs.

The objective of this study was to investigate the impacts of replacing alfalfa hay with Artemisia sieberi leaves (ASL) on growth performance, feeding behaviors, total tract feed digestibility, ruminal fermentation as well as blood cells, and biochemical parameters. A total of 21 Kermani male lambs (average body weight (BW) of 25.2 ± 0.9 kg) were randomly divided into three groups and offered the following treatments: (1) basal diet (65% concentrate and 35% alfalfa hay as forage source), (2) ASL inclusion at 25% of forage source (8.75% of TMR, ASL25), and (3) ASL addition at 50% of forage source (17.5% of TMR, ASL50). The experiment lasted for 64 days, including 14 days of adaptation and 50 days of data collection. Dietary ASL inclusion decreased lambs' feed consumption (6.7 and 2.8% reduction in ASL25 and ASL50, respectively, p < 0.05) without affecting water intake, final BW, daily weight gain, and feed conversion ratio. Moreover, feeding behaviors, including time spent for eating, ruminating, and chewing activities, were uninfluenced by the dietary ASL addition on days 25 and 50 of the experiment. Based on the data provided, the substitution of alfalfa hay with ASL resulted in an increase in the digestibility of dry matter, organic matter, and neutral detergent fiber (p < 0.05). In addition, the ruminal fluid of ASL-fed lambs had a lower molar proportion of acetate and a higher proportion of propionate compared to that of the control animals (p < 0.05), whereas other volatile fatty acids (VFA) and total VFA were not different between the experimental groups. Blood hematocrit, hemoglobin, red cells, white cells, and their differentiation, platelets, glucose, total protein, albumin, globulin, triglyceride, calcium, phosphorus, aspartate aminotransferase, and alanine aminotransferase, urea, total antioxidant capacity, and malondialdehyde remained unchanged when ASL was included in the diet. Regardless of the slight decrease in dry matter intake, the lack of adverse effects of dietary ASL addition on growth performance, feeding behaviors, rumen fermentation, and blood hemato-biochemical parameters, along with positive impacts of ASL on propionate production and total tract feed digestibility, suggest that Artemisia sieberi leaves can be considered as a potential alternative feed resource for small ruminants.

Genetics and non-genetics parameters of body weight for post-weaning traits in Raini Cashmere goats.

Genetic parameters were estimated for 6-month weight (W6), 9-month weight (W9), 12-month weight (W12), average daily gain from birth to 6 months old (ADG6), and Kleiber ratio at 6 months (KL6) traits using 6,442 records obtained from a Raini Cashmere goat flock. The parameters were estimated using the restricted maximum likelihood procedure and applying four animal models excluding or including maternal additive genetic and permanent environmental effects. Heritability estimates for W6, W9, W12, ADG6, and KL6, under the most appropriate model were 0.028, 0.26, 0.29, 0.02, and 0.25, respectively. The estimates of genetic and phenotypic correlations among W6, W9, W12, and ADG6 were high and ranged from 0.73 to 0.99. The estimates of genetic and phenotypic correlations among KL6 and others traits were negative and low. Thus, these estimates of genetic parameters may provide a basis for deriving selection indices for postweaning growth traits also low genetic correlation between growth traits with KL6, it is possible to increase efficiency in Raini kids by multitrait selection.

Estimating non-genetic and genetic parameters of pre-weaning growth traits in Raini Cashmere goat.

Data and pedigree information used in the present study were 3,022 records of kids obtained from the breeding station of Raini goat. The studied traits were birth weight (BW), weaning weight (WW), average daily gain from birth to weaning (ADG) and Kleiber ratio at weaning (KR). The model included the fixed effects of sex of kid, type of birth, age of dam, year of birth, month of birth, and age of kid (days) as covariate that had significant effects, and random effects direct additive genetic, maternal additive genetic, maternal permanent environmental effects and residual. (Co) variance components were estimated using univariate and multivariate analysis by WOMBAT software applying four animal models including and ignoring maternal effects. Likelihood ratio test used to determine the most appropriate models. Heritability (h(a)(2)) estimates for BW, WW, ADG, and KR according to suitable model were 0.12 ± 0.05, 0.08 ± 0.06, 0.10 ± 0.06, and 0.06 ± 0.05, respectively. Estimates of the proportion of maternal permanent environmental effect to phenotypic variance (c(2)) were 0.17 ± 0.03, 0.07 ± 0.03, and 0.07 ± 0.03 for BW, WW, and ADG, respectively. Genetic correlations among traits were positive and ranged from 0.53 (BW-ADG) to 1.00 (WW-ADG, WW-KR, and ADG-KR). The maternal permanent environmental correlations between BW-WW, BW-ADG, and WW-ADG were 0.54, 0.48, and 0.99, respectively. Results indicated that maternal effects, especially maternal permanent environmental effects are an important source of variation in pre-weaning growth trait and ignoring those in the model redound incorrect genetic evaluation of kids.

Lamb survival analysis from birth to weaning in Iranian Kermani sheep.

Survival records from 1,763 Kermani lambs born between 1996 and 2004 from 294 ewes and 81 rams were used to determine genetic and non-genetic factors affecting lamb survival. Traits included were lamb survival across five periods from birth to 7, 14, 56, 70, and 90 days of age. Traits were analyzed under Weibull proportional hazard sire models. Several binary analyses were also conducted using animal models. Statistical models included the fixed class effects of sex of lamb, month and year of birth, a covariate effect of birth weight, and random genetic effects of both sire (in survival analyses) and animal (in binary analyses). The average survival to 90 days of age was 94.8%. Hazard rates ranged from 1.00 (birth to 90 days of age) to 1.73 (birth to 7 days of age) between the two sexes indicating that male lambs were at higher risk of mortality than females (P < 0.01). This study also revealed a curvilinear relationship between lamb survival and lamb birth weight, suggesting that viability and birth weight could be considered simultaneously in the selection programs to obtain optimal birth weight in Kermani lambs. Estimates of heritabilities from survival analyses were medium and ranged from 0.23 to 0.29. In addition, heritability estimates obtained from binary analyses were low and varied from 0.04 to 0.09. The results of this study suggest that progress in survival traits could be possible through managerial strategies and genetic selection.