Jungang Guo;Xuezhuang Wu;Tietao Zhang;Zhi Liu;Cui Hu;Fayu Yang;Xiuhua Ga

Institute of Special Wild Economic Animals and Plants, Chinese Academy of Agricultural Sciences, Changchun 130112, China;Institute of Special Wild Economic Animals and Plants, Chinese Academy of Agricultural Sciences, Changchun 130112, China;Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, Chin;Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China

Blue fox;Growth performance;Methionine;Nitrogen metabolism;Nutrient digestibility;Serum biochemical indicator

The objective of the present study was to investigate the effects of methionine (Met) supplementation on growth performance of cubs, nutrient digestibility, nitrogen metabolism and serum biochemical parameters of female blue foxes. One hundred primiparous female blue foxes that were similar in breeding date, pedigree, age, and weight were selected for the trial. The foxes were randomly assigned to four groups (n = 25 each group) and fed diets supplemented with Met at 2 (Met2), 4 (Met4), 6 (Met6) and 8 g/kg (Met8), respectively, for 40 days. Our data showed that body weights at 20 and 40 d were significantly higher in the Met4 group than in the Met2 group (P < 0.05). The Met4 group also had the highest apparent digestibility of dry matter and crude protein compared with either the Met2, Met6, or Met8 group (P < 0.05). The serum Met and isoleucine (Ile) concentrations were significantly higher in the Met4 group than in the Met6 or Met8 group (P < 0.05). In summary, these data indicate that supplementary Met improves growth performance of cubs likely due to increased crude protein and dry matter and increased nitrogen retention of female blue foxes. The optimal amount of Met supplementation is 10 g/kg basal diet.