载锌沸石对肉鸡生产性能、抗氧化功能及其相关基因表达的影响

研究载锌沸石(Zn CP,锌含量为15.5 mg/g)对肉鸡生产性能、肝脏锌沉积、抗氧化功能及其相关基因表达的影响,探讨Zn CP作为抗生素替代品的可行性。300只1日龄AA(Arbor Acres)肉鸡随机分成5组,每组6个重复,每个重复10只鸡,试验期为42 d。试验日粮:1)对照组,基础日粮(含Zn SO4,锌含量为60mg/kg);2)基础日粮+抗生素(40 mg/kg金霉素);3)基础日粮+0.1%Zn CP;4)基础日粮+0.2%Zn CP;5)基础日粮+0.4%Zn CP。结果表明,与对照组相比,不同剂量Zn CP显著提高肉鸡前期体增重(P0.05),0.1%和0.2%的Zn CP显著提高21 d肝脏T-SOD和Cu Zn-SOD的活性(P0.05),0.2%的Zn CP显著降低21 d肝脏MDA含量(P0.05),抗生素组和Zn CP组均能显著提高21 d肝脏T-AOC(P0.05);与抗生素组相比,0.1%和0.2%的Zn CP显著降低21 d肝脏MDA含量(P0.05),显著提高21 d肝脏T-SOD的活性(P0.05),0.1%的Zn CP显著提高42 d肉鸡肝脏Nrf2 mRNA的相对表达量(P0.05)。与对照组和抗生素组相比,0.2%的Zn CP显著降低42 d肉鸡肝脏MDA含量(P0.05)。结果提示,肉鸡日粮中添加Zn CP能提高生产性能,效果等同或优于抗生素;Zn CP可能通过提高Keap1/Nrf2/ARE/抗氧化酶信号通路关键基因Nrf2的表达量来提高肉鸡的抗氧化能力;本试验条件下,日粮中Zn CP以0.1%和0.2%的添加量较好。

Effects of zinc-bearing clinoptilolite on growth performance, antioxidant function and genes expression of broiler chickens

This study was conducted to evaluate the effect of zinc-bearing clinoptilolite (ZnCP, containing Zn 15.5 mg/g) addition replacing antibiotics on growth performance, Zn contant in liver, antioxidant function and relevant genes expression of broiler chickens. A total of 300 one-day-old Arbor Acres chickens were randomly divided into 5 groups with 6 replicates of 10 birds for a 42-d feeding trial. The dietary treatments were as follows: 1) control (CON) fed a basal diet with 60 mg/kg zinc from zinc sulphate; 2) the basal diet plus antibiotics (ANT, 40 mg chlortetracycline per kg of diet); 3) the basal diet plus 0.1% ZnCP; 4) the basal diet plus 0.2% ZnCP; 5) the basal diet plus 0.4% ZnCP. The results showed that compared to CON, ZnCP treatments caused positive effects on BWG (P<0.05) of broilers during 1-21 d. The activities of T-SOD and Cu-Zn SOD in liver were increased by 0.1% and 0.2% ZnCP at 21 d (P<0.05). MDA contents in liver at 21 d were reduced by 0.2% ZnCP (P<0.05). ANT and ZnCP treatments increased T-AOC in liver at 21 d (P<0.05).Compared to ANT, 0.1% and 0.2% ZnCP reduced MDA contents (P<0.05) and increased T-SOD activity in liver at 21 d (P<0.05). Nrf2 mRNA level in liver was upregulated by 0.1% ZnCP at 42 d (P<0.05). Compared to CON and ANT, 0.2% ZnCP improved MDA contents in liver at 42 d (P<0.05). The results suggested that addition of 0.1% or 0.2% ZnCP improved growth performance of broiler chickens, and the effect is equivalent to or better than antibiotics. ZnCP can improve antioxidant function of broiler chickens by elevating the Nrf2 mRNA expression of Keap1/Nrf2/ARE/ signaling pathway.