Effects of winter and spring housing on growth performance and blood metabolites of Pengbo semi-wool sheep in Tibet

Objective: Sixty Pengbo semi-wool sheep ewes (approximately 1.5-years-old; 31.33 ± 0.43 kg) were randomly assigned to two groups, either G (grazing) or D (dry lot feeding), to examine the effects of traditional daily grazing and dry lot feeding on performance and blood metabolites during the cold season in Tibetan Plateau. Methods: The ewes in the G group were grazed continuously each day and housed in one shed each evening, while the ewes in the D group were housed in another shed all day. All animals were fed 400 g/day of commercial concentrate, and grass hay was available freely throughout the experimental period. Results: Compared with the G group, the ewes in the D group had higher (p < 0.05) live weight and weight gain. The D group ewes had greater (p < 0.05) numbers of white blood cells and platelets, while they had lower (p < 0.05) platelet-large cell ratios, cholesterol, high-density lipoprotein cholesterol and glutathione peroxidase, as compared with the G group ewes. Additionally, three serum metabolites, abscisic acid, xanthoxin and 3,4-dihydroxy-5-polypren, were upregulated (p < 0.05) in the D group in comparison with the G group. Conclusion: In conclusion, a dry lot feeding regime during the winter and spring period will increase the productivity of sheep and improve blood physiological and biochemical profiles.