Effect of lignin polyphenols and copper-zinc cross-linking substance combined supplementation on growth performance, immunity and copper, zinc deposition of weaned piglets.

The study was to investigate the effect of lignin polyphenols and copper-zinc cross-linking substance combined supplementation on growth performance, immunity and copper, zinc deposition of weaned piglets. Ninety-six healthy weaned piglets (Duroc x Landrace x Yorkshire) with similar body weight were selected and randomly divided into three groups, with four replicates in each group and eight pigs in each replicate. The control group piglets were fed with basal diet + 2 kg/t zinc oxide + 100 g/t chlortetracycline + 40 g/t colistin, T1 group piglets were fed with basal diet + 1 kg/t lignin polyphenols + 700 g/t copper-zinc cross-linking substance, T2 group piglets were fed with basal diet + 2 kg/t lignin polyphenols + 700 g/t copper-zinc cross-linking substance. The pre-feeding period lasted for 7 d, the formal experiment lasted for 28 d. The results showed that compared with control group, the average daily feed intake and average daily gain of piglets in T2 group were slightly increased ( P>0.05), the average daily feed intake of T1 group was significantly decreased (P<0.05). There was no significant difference in feed to gain ratio and diarrhea rate of piglets among all groups (P>0.05). Compared with control group, the content of IFN-γ in serum of piglets in T1 group was significantly decreased (P<0.05). Compared with control group and T1 group, the content of C4 in serum of piglets in T2 group was significantly increased and significantly higher than that in T1 group ( P<0.05), the content of DLA in serum of piglets in T2 group was significantly decreased and significantly lower than that in T1 group (P<0.05). Compared with control group, the content of zinc in serum and feces of piglets in T1 group and T2 group were significantly decreased ( P<0.05). The study indicates that the combined addition of 2 kg/t lignin polyphenols and 700 g/t copper-zinc cross-linking substance to weaned piglet diet to replace the combination of high zinc and antibiotics can maintain the normal growth performance of weaned piglets, improve immunity, significantly reduce the excretion of zinc in the feces. [ABSTRACT FROM AUTHOR]