Effects of different diets on growth performance, physiological parameters of digestive tract and apparent digestibility in geese

Abstract

This experiment was conducted to compare the effects of different diets, containing different fibre sources, on growth performance, hormones level, digestive enzyme activity, intestinal canal morphology, and apparent digestibility. In the first experiment, a total of 216 three-weeks-old Yangzhou goslings were distributed into six pens of 36 birds/pen (18 males and 18 females). Each treatment was represented by three replicates. The experimental diets for the six different treatments with corresponding Groups 1 to 6 were supplemented with corn-soybean-based, alfalfa meal, wheat bran and ryegrass, respectively as the major source of fibre, and the contents of these three fodders were 14, 16, 18, 20, 22 and 24% respectively, severally corresponding to diets 1 to 6. In the second experiment, eighteen 10-weeks-old male geese were placed in metabolism cages, and the birds of treatments 1 to 6 received diets 1 to 6, respectively. The results show that the feed intakes of Group 3 were the most, but there were no significant differences among these six groups (P > 0.05). The body weight (BW) of Group 3 geese was the biggest; moreover they appeared different to a certain extent. The contents of triiodothyronine (T₃) and growth hormone (GH) in Group 3 were the highest, thereinto the content of T₃ in Group 3 was more than other groups except Group 2, and the content of GH in Group 3 was more than Groups 5 and 6 (P < 0.05). The digestive enzyme activity in intestinal tract in Group 3 was the most, but there was no significant difference among these six groups (P > 0.05). The intestinal wall thickness of duodenum, jejunum and cecum in Group 3 was the most, in the same way, the villus height of duodenum in Group 3 was also the most. However, the intestinal wall thickness and villus height in Groups 5 and 6 were generally less. When the proportion of alfalfa, ryegrass and wheat bran in dietary was more than 18%, the apparent nutrient digestive ratios decreased. The current study indicates that the feasible proportion of alfalfa, ryegrass and wheat bran in diet in geese was 18%.

Key words: Fibre, goose, growth performance, digestive enzyme, digestibility.