Effects of glutamine on growth performance and immune function of high-concentrate fattening Hu lambs.

The objective of this study was to investigate the effects of glutamine (Gln) on the growth performance and immune function of high-concentrate fattening lambs. Thirty 3-month-old male healthy Hu sheep with a similar body weight of 26.75 ± 0.65 kg were randomly selected and assigned to 3 groups with 10 lambs per group. Lambs in 3 groups were fed basic diets supplemented with 0 (control group, fed a high-concentrate diet), 0.5% (Gln1, fed a high-concentrate diet), or 1.0% (Gln 2, fed a high-concentrate diet) Gln. The pre-experimental period lasted for 15 days, and the experimental period lasted for 45 days. The obtained results showed that compared with the CON group, the Gln group showed a lower F/G from 16 to 30 d, 31–45 d, and 0–45 d (P < 0.05); increased heart weight, heart index, spleen weight, spleen index, thymus weight, thymus index, small intestine weight, and small intestine index on day 45 (P < 0.05); increased concentration of CD4+ and CD8+, CD4+/CD8+ T lymphocyte ratios, lymphocyte transformation ratio in peripheral blood, and IgG content and IL-2 ratio in plasma (P < 0.05); decreased apoptosis ratio in peripheral blood on days 15, 30, and 45 (P < 0.05). However, there was no difference in these parameters compared to the Gln group (P > 0.05). In summary, this study showed that dietary Gln supplementation may improve the immune function of lambs by providing energy to the proliferation of T cells. • Gln group showed a lower F/G from 16 to 30 d, 31–45 d, and 0–45 d (P < 0.05), increased the organ index of heart, spleen, thymus, and small intestine on the 45 days (P < 0.05). • The inclusion of Gln showed increased the CD4+ and CD8+ concentration, the CD4+/CD8+ T lymphocyte ratios, the peripheral blood lymphocytes transformation ratio, and the serum IgG and IL-2 levels (P < 0.05), and decreased the peripheral blood apoptosis ratio on the 15, 30, and 45 days (P < 0.05). • These results suggest that dietary Gln supplementation might improve the immune function of lamb by providing energy to the proliferation of T cells. [ABSTRACT FROM AUTHOR]