Dietary supplementation with Lonicera macranthoides leaf powder enhances growth performance and muscle growth of Chinese Tibetan pigs

This study was conducted to explore the effects of dietary supplementation with Lonicera macranthoides leaf (LML) on growth performance and muscle growth of Chinese Tibetan pigs. L. macranthoides leaves were harvested, air-dried, and milled to powder. Ninety-six pigs with an average initial body weight of 5.03 ± 0.24 kg were randomly assigned into four groups (24 pigs per group) in a completely randomized design according to the body weight. Pigs were fed either a basal diet with no supplement (control), or a diet supplemented with 0.5%, 1.0%, or 1.5% of LML powder. Results showed that dietary supplementation with 1.5% powder increased ADG and lean percentage, improved the gain:feed ratio, and lowered the incidence of diarrhea in Tibetan pigs (P < 0.05), compared with the control group. Moreover, dietary supplementation with 1.0% and 1.5% powder increased the concentration of several free amino acids in the longissimus dorsi muscle and the mRNA expression of selected AA transporters, significantly upregulated the mRNA expression of genes related to muscle growth (P < 0.05). In conclusion, these results suggested that the dietary level of LML powder within the range of 1.0-1.5% would facilitate the absorption and utilization of free AA, thus improving muscle growth and growth performance of Chinese Tibetan pigs.