Weaning Ages Do Not Affect the Overall Growth or Carcass Traits of Hu Sheep

Abstract

This study aimed to determine effects of weaning ages on growth, rumen development, and carcass characteristics and meat quality of Hu lambs. Thirty male Hu lambs were randomly divided into two weaning age groups: Weaned at 30 (W30) or 45 (W45) d of age. Blood samples were collected on the day of weaning before lambs (n = 5) were slaughtered, and then rumen sample was collected immediately after they were slaughtered. The intake of all feeds increased with age (p < 0.05), but were not affected by weaning age (p > 0.05). Oxidative stress indicators and immune variables, the plasma biochemical parameters did not differ between the two different weaning ages (p > 0.05). The two weaning age groups also had similar (p > 0.05) concentration of ruminal total volatile fatty acid. The two weaning age groups did not differ in body weight, carcass characteristics, or meat quality (p > 0.05) at d 120. These results indicate that weaning half a month earlier than the typical weaning age does not significantly affect the growth, ruminal development, or carcass characteristics of Hu lambs, and they can be weaned at 30 d of age to improve production efficiency.

Weaning Age Affects the Development of the Ruminal Bacterial and Archaeal Community in Hu Lambs During Early Life

“…No functional feature was found to differ between W45 and PW45 lambs by LEfSe. levels of feed intake (Mao et al, 2019b), allowing us to determine the effects of weaning age on the aforementioned measures. Additionally, we investigated whether weaning stress influenced microbial colonization in the rumen, information that may aid the selection of an appropriate weaning age.…”

“…As part of a previous study ( Mao et al, 2019b ), rumen samples were collected from Hu lambs. Briefly, 30 healthy male Hu lambs (3.60 ± 0.37 kg) at 5 days of age were selected, maintained at a breeding farm and fed milk replacer (MR).…”

“…Immediately after slaughter, rumen content samples were collected and stored at −80°C for subsequent microbial DNA extraction, and rumen tissues were sampled to measure ruminal papillae length. Additional procedures are as described in Mao et al (2019b) , with the exception that in the present study, data collected on the day of animal sacrifice were used for bacterial and archaeal analysis.…”

“…A significant difference was declared at 0.5 < R < 0.75 with P < 0.05, whereas a trend was declared at 0.3 < R < 0.5 with P < 0.05, and no difference was declared at R < 0.3. Data on plasma D -lactate concentration, rumen papillae length and width, and ruminal total VFA concentrations were obtained from our previous study ( Mao et al, 2019b ) and analyzed for correlations with bacterial taxa. Based on comparison of the 16S rRNA gene sequences against a Green genes reference taxonomy (Green genes 13.8), the functional capabilities of the rumen microbiota were predicted by using PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) ( Langille et al, 2013 ).…”

“…As part of a previous study (Mao et al, 2019b), rumen samples were collected from Hu lambs. Briefly, 30 healthy male Hu lambs (3.60 ± 0.37 kg) at 5 days of age were selected, maintained Abbreviations: ANOSIM, analysis of similarity; ANOVA, analysis of variance; DNA, deoxyribonucleic acid; KO, KEGG orthology; LEfSe, linear discriminate analysis effect size; MR, milk replacer; OTU, operational taxonomic unit; PCoA, principal coordinate analysis; PICRUSt, phylogenetic investigation of communities by reconstruction of unobserved states; VFA, volatile fatty acid.…”