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

SIMPLE SUMMARY: Early weaning increases the production efficiency of food animals. However, the success of early weaning is limited, in part, by the rate of ruminal volume and functional development, and the establishment of a functional rumen microbiome. Decades of research have focused on the effects of weaning age on the growth of sheep, but there is limited information on how weaning age affects ruminal development, fermentation profiles, and host biochemical and immune responses. Effect of weaning ages (30 vs. 45 d) of Hu lambs on the growth performance before weaning, rumen development when weaning, as well as carcass characteristics and meat quality after weaning were determined in this study. Our goal was to find if Hu sheep can be weaned younger than 45 d. The results of this study showed that there were no significant differences between the two weaning age groups on the growth performance, rumen development, slaughter characteristics, and meat quality, and thus weaning at d 30 could be recommended to save the feeding cost. 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.