Effects Of Levels Of Zn In Ration On Production And Biochemical Parameters For Cage-rearing Laying Ducks

An experiment was conducted to study the roles of zinc in ducks with corn-soybean mealbasal diet.120 healthy 28-day-old Jinding ducks were randomly divided into 5 goups with 6eplicates of 4 ducks per group. The zinc additive levels were 0, 30, 60, 200, 1000 mg/kg in basaldiet, making 5 kinds diet, each kind of diet for 6 group ducks. 6 weeks studied the influence ofdietary zinc levels on growth, immune response, some important serum enzymes, thyroid gland andtotal anti-oxidant capability and so on.The results showed that low level of zinc had significant bad effect on growth, Along with theincreasing of zinc, the average daily gain increase for ducks. Result showed that high zinc adding(1000mg/kg) the average daily gain increase for ducks obvious, but tried a duck didn't express oneobvious of opoisoned evidence.The results showed that low level of zinc(0mg/kg) and high level of zinc (1000mg/kg) bothhad significant effect on immune response. Along with the increasing of zinc, the immune responseincreasing in varying degree for ducks. But in high level of zinc (1000mg/kg), the immuneresponse could be suppressed. This experiment indicated that adding 30mg/kg zinc in corn—soybeanmeal basal diet (contain zinc 32.9mg/kg) that raising laying ducks in cages could be possible tomeet the growth needs, suitably increaseing zinc content in feedstuff could be possible to increaseimmune response.The results showed three idodines armor gland original ammonia acid (T₃), the uric acid(URIC), the amylase (AMY), total anti-oxidant capability(T-AOC) and so on, along with the zinclevel increasing, T₃, URIC, AMY and T-AOC and so on increase in varying degree, but high levelof zinc (1000mg/kg), URIC, AMY and T-AOC and so on were suppressed in varying degree.The results showed that increaseing zinc content in feedstuff couldn't significantly influencethe efficiency of Na, K, Cl, and P(P＞0.05). The results showed that level of zinc had significanteffect on Ca, the level of Ca with the lowest level of zinc as 0mg/kg, and zinc as 60mg/kg hassignificant effect with 1000mg/kg (P＜0.05); The results showed that level of zinc had significanteffect on P between the level as 200mg/kg and 60mg/kg (P＜0.05), and the level of P with thehighest level in zinc as 200mg/kg, and the lowest zinc as 60mg/kg, but the level as 200mg/kg and60mg/kg had no significant effect on P with other groups (P＞0.05).The results showed that level of zinc could influence the efficiency AG, and the results showedthat level of zinc had significant effect on AG between the level as 0mg/kg with 200mg/kg and1000mg/kg (P＜0.05), The results of serum biochemical indexes showed that PH and CO₂ has not significant effect each other (P＞0.05).The results showed that the ducks were fed with 200 mg/kg and 1000mg/kg serum T₄ waslower than with 30 mg/kg remarkably (P＜0.05) but the its growth function level is very high, mayhave something to do with insulin, IGF-I. Whether high level zinc repress a function towardsgrowing the duck T4 or not, still need a further research.According to growth, serum biochemical indexes and the immunity indexes variety analysis ofthe same term, this experiment indicated that adding 30 mg/kg zinc in corn-soybean meal basaldiet (contain zinc 32.9mg/kg) that raising laying ducks in cages could be possible to meet thegrowth needs, suitably increaseing zinc content in feedstuff could be possible to increase immuneresponse and T-AOC, it is suggested that the optimal supplement amount of zinc was from 30mg/kg to 60 mg/kg under cage condition at the stage of young laying ducks.