Effects of Zinc Glycine Chelate on Oxidative Stress, Contents of Trace Elements, and Intestinal Morphology in Broilers
文摘
Three hundred and sixty healthy Ross?×?Ross 1-day-old broilers were used to study the effects of zinc glycine chelate (Zn-Gly) on oxidative stress, contents of trace elements, and intestinal morphology. All broilers were randomly assigned to six treatment groups, which replicates three times. Diets were as follows: (1) control (containing 29.3?mg zinc (Zn)/kg basic diet (0-1?days) and 27.8?mg Zn/kg (22-2?days)); (2) basic diet plus 30?mg Zn/kg from Zn-Gly; (3) basic diet plus 60?mg Zn/kg from Zn-Gly; (4) basic diet plus 90?mg Zn/kg from Zn-Gly; (5) basic diet plus 120?mg Zn/kg from Zn-Gly; and (6) positive control, basic diet plus 120?mg Zn/kg from zinc sulfate (ZnSO4). The results showed that the addition of 90 or 120?mg/kg Zn-Gly led to an improvement of activity of Cu/Zn superoxide dismutase and glutathione peroxidase and a reduction of malondialdehyde content in livers at 21 and 42?days. With 90?mg/kg Zn-Gly, the content of sera zinc increased by 17.55% (P-lt;-.05) in 21-day broilers and 10.77% (P-gt;-.05) in 42-day broilers compared with that of the control. Adding 120?mg/kg Zn-Gly or ZnSO4 to broilers' diets greatly enhanced the content of zinc in feces at 21?days (P-lt;-.05) and at 42?days (P-lt;-.05). For 42-day chickens, increased villus height and decreased crypt depth of the jejunum could be observed in the second growth stage of broilers fed with 90?mg/kg Zn-Gly. Also, intestinal wall thickness decreased (P-lt;-.05). In addition, adding 90?mg/kg Zn-Gly to the diet markedly elevated villus length of duodenum and decreased crypt depth of ileum (P-lt;-.05) in 42-day broilers.