Growth, carcass, and physiological traits of growing male China Micro-ducks fed various levels of dietary crude fibre

The objective of this study was to evaluate the responses of growth performance, organ development, carcass characteristics, and serum biochemical parameters to the diets with different levels of crude fibre (CF) in growing male China Micro-ducks (CMD). A total of 240 nineteen-day-old CMD were blocked on the basis of body weight, and then randomly allocated to four treatments, each with 6 replicate pens of 10 ducklings. The formal feeding experiment lasted for 35 days. The CF levels for four diets were 16.7, 42.6, 77.9, and 101.6 g/kg of dry matter (DM), respectively. The diet with the CF level of 101.6 g/kg of DM resulted in the first-rank growth performance, followed by the diets with the CF level of 42.6 and 77.9 g/kg of DM, and then the diet with the CF level of 16.7 g/kg of DM. The diet with the CF level of 42.6 g/kg of DM led to the optimum slaughter performance, followed by the diets with the CF levels of 16.7 and 77.9 g/kg of DM, and then the diet with the CF level of 101.6 g/kg of DM. With the increase of the CF level in the diets, the serum glucose concentration and the relative weights of proventriculus and gizzard significantly rose (P < 0.05), but the serum concentrations of low-density lipoprotein cholesterol and creatinine, the percentages of head, feet, and abdominal fat, and the relative weights of liver, jejunum, and ileum significantly decreased (P < 0.05). For the percentages of pectoral muscle and lean meat and the relative weight of thymus, dietary treatment with the CF level of 16.7 g/kg of DM was significantly lower than the other dietary treatments (P < 0.05). The recommended range of dietary CF level for growing male CMD should therefore be between 42.6 and 77.9 g/kg of DM.