Effect of Zinc Resources and Levels on Serum Hormone Levels of Weanling Stress Piglets

【Objective】The purpose of this experiment was to study the effects of different dozes and kinds of high zinc diets on serum hormone levels of weanling stress piglets.【Method】One hundred “Duroc ×Landrace×Yorkshire” crossbred weanling piglets [(26 ±2) d of age] were randomly divided into 5 groups of 20 piglets each by weight and sex,fed with basal diet,basal diet plus 2 000 or 3 000 mg.kg-1 zinc(from ZnO),and basal diet plus 250 or 500 mg.kg-1 zinc(from Zn-Met),respectively.The trial was conducted for 14 d.Blood samples were taken from the anterior vena cava for measuring some serum hormone levels.【Result】High zinc diets increased significantly absolute weight,average daily gain,and average daily feed intake of weanling stress piglets,decreased the ratio of feed to gain and postweaning diarrhea rates.Serum GH,INS,IGF-I,T3 levels of weanling stress piglets decreased,and serum cortisol levels increased significantly.High zinc diets increased significantly serum GH,INS,IGF-I,and T3 levels.【Conclusion】The results showed that high zinc diet can inhibit weanling stress and modulate growth-promoting hormone axis of piglets.