Effects of zinc-methionine on growth performance, intestinal flora and immune function in pigeon squabs

1. Different concentrations of zinc-methionine (Zn-Met) were given to pigeon squabs, and the resulting effects on growth, immune functions and intestinal microflora were investigated from hatching to 28d of age. A total of 180 artificially hatched pigeon squabs were randomly allotted to each of three treatments with three replicates of 20 squabs. The three treatments given were either oneml (2mg/ml) Zn-Met, oneml (10mg/ml) Zn-Met or oneml 0.9% NaCl solution.2. The results showed that Zn-Met improved the growth performance of squabs. The average daily and average weekly weight gain was significantly greater in squabs treated with Zn-Met than in the control group.3. The group given 2 and 10mg supplemental Zn-Met had heavier thymus, spleen and bursa of Fabricius than the control group at d 28.4. Maternal antibody titres against Newcastle disease haemagglutination inhibition and alpha-naphthyl acetate esterase were significantly higher in squabs treated with supplemental 2 and 10mg Zn-Met compared to the control group at d 14 and d 28.5. Additionally, the squabs given supplemental 2mg Zn-Met exhibited significantly higher Bacillaceae, Lactobacillus, Enterococcus and Bifidobacterium populations at d 14 and d 28, but lower Escherichia coli populations at d 28 compared to the control group. On the contrary, Lactobacillus, Enterococcus and Bifidobacterium populations were significantly decreased with 10mg Zn-Met at d 28.6. This study indicates that supplementation with Zn-Met has a positive effect on growth performance, immune function and regulation of intestinal flora in pigeons. An inclusion level of 2mg seems to be better than 10mg Zn-Met per day per bird.