Effects Of Dietary Threonine On Growth Performance, Immune Function And Serum Biochemical Parameter At 0-8 Weeks Of Goslings

A study was conducted to evaluate the effect of dietary threonine levels on growth performance, carcass traits, immune function and serum biochemical parameter to determined the optimum threonine level for 0-8 weeks old Yangzhou goslings.Experiment 1: A dose-response experiment with 5 dietary threonine (Thr) levels (0.54(basal diet), 0.64, 0.74, 0.84 and 0.94%) was conducted to study the effect of dietary Thr on growth performance, carcass traits, meat quality and serum biochemical parameters of Yangzhou goslings from 0 to 8 wks of age. Three hundred day old Yangzhou goslings were randomly allocated to 15 pens with 20 birds (10 males and 10 females) per pen according to similar pen weight. There were 5 dietary treatments, each containing 3 replicate pens. The maize-peanut meal basal diets were on basis of total amino acids.The results showed as follows: The result showed that an increase in dietary Thr resulted in an increase and then a decrease in daily weight gain in 0-8 wk period. Thr supplementation significantly affected weight and feed:gain in the 0-4 wk period (P<0.05) and daily feed intake in the 5-8 wk period. Peak daily weight gain and daily feed intake responses all appeared in 0.74% Thr diet in both periods. The optimum feed: gain appeared in 0.74% Thr diet at 0-4 wk and 0.84% Thr diet at 5-8 wk.Thr supplementation had no siginificantly effect on carcass quality and meat quality as well as serum biochemical parameters.Nevertheless peak aspartate aminotransferase and alanine aminotransferase activity appeared in 0.74%-0.84% Thr diet at 0-4 wk and 0.64% in the 5-8 wk period.The optimum ratio of Thr/Lys appeared in 0.74% Thr diet as to uric acid. The results of experiment 1 would suggest Thr requirement of gosling from 0 to 8 wk of age was 0.74%-0.84% for growth performance.. Experiment 2: A dose-response experiment with 6 dietary threonine (Thr) levels (0.54(non-immue basal diet), 0.54(basal diet), 0.64, 0.74, 0.84 and 0.94%) was conducted to study the effect of dietary Thr on immune function of Yangzhou goslings from 0 to 8 wks of age. Three hundred and sixty day old Yangzhou goslings were randomly allocated to 18 pens with 20 birds (10 males and 10 females) per pen according to similar pen weight. There were 6 dietary treatments, each containing 3 replicate pens. The maize-peanut meal basal diet were on basis of total amino acids.The results showed as follows: There were no significant responses from Thr level observed for immune organ index, serum antibody level, serum total protein, serum albumin, serum giobulin and A/G..Results showed that an increase in dietary Thr result in no significant effect for spleen acid phosphatase. Peak spleen acid phosphatase of goslings appeared in the gosling fed the 0.74%-0.94% Thr diet. The results of experiment 2 would suggest Thr requirement of gosling from 0 to 8 wk of age was 0.74%-0.94% for immune function.