低钙、磷水平饲粮添加高剂量植酸酶对1～42日龄黄羽肉鸡生长性能、胫骨指标和钙磷代谢的影响

Effects of Low Calcium and Phosphorus Diet Supplemented with High Dose Phytase on Growth Performance,Tibia Indexes and Calcium and Phosphorus Metabolism of Yellow-Feathered Chickens Aged from 1 to 42 Days

本试验旨在研究低钙、磷水平饲粮添加高剂量植酸酶对1～42日龄黄羽肉鸡生长性能、胫骨指标和钙磷代谢的影响。试验选用1 080只1日龄岭南黄羽肉公雏,随机分为6个组,每组6个重复,每个重复30只。正对照组(PC组)饲喂基础饲粮,正常添加磷酸氢钙;中钙、磷水平饲粮组(MP组)磷酸氢钙添加量降低50%,MP+2000、MP+4000组分别在MP组基础上添加2 000、4 000 FTU/kg植酸酶;低钙、磷水平饲粮组(LP组)不添加磷酸氢钙,LP+2000、LP+4000组分别在LP组基础上添加2 000、4 000 FTU/kg植酸酶。各组钙磷比保持在1.4∶1.0。试验期42 d。结果表明:1)各植酸酶添加组体重、平均日增重、平均日采食量显著高于MP组(P <0.05),且MP+4000、LP+4000组显著高于PC组(P<0.05)。2) MP+2000、MP+4000组胫骨骨密度显著高于MP组(P <0.05);各植酸酶添加组胫骨脱脂脱水重显著高于MP组(P <0.05),LP+4000、MP+2000、MP+4000组显著高于PC组(P <0. 05); LP+2000、LP+4000组胫骨灰分含量显著低于MP、PC组(P<0.05); LP+2000组胫骨磷、钙含量显著低于MP、PC组(P<0.05)。3)各植酸酶添加组血清碱性磷酸酶活性显著低于MP组(P<0.05)。4) MP+4000组肾脏成纤维生长因子受体1(Fgfr1)的表达量显著高于MP、PC组(P<0.05)。5) LP+4000组粪钙含量显著低于MP组(P<0.05),LP+2000、LP+4000组显著低于PC组(P<0.05); LP+2000、LP+4000组粪磷含量显著低于MP组(P <0.05),MP+4000、LP+2000、LP+4000组显著低于PC组(P <0.05); LP+4000组钙代谢率显著高于PC组(P <0.05)。综上,低钙、磷水平饲粮添加高剂量植酸酶可提高1～42日龄黄羽肉鸡生长性能,提高胫骨脱水脱脂重,降低血清碱性磷酸酶活性。中钙、磷水平饲粮添加高剂量植酸酶可提高胫骨密度,上调肾脏Fgfr1基因的表达。仅考虑生长性能、血清生化指标、胫骨指标及钙磷代谢指标,1～42日龄岭南黄羽肉鸡玉米-豆粕型饲粮中添加高剂量植酸酶可以部分或者完全代替磷酸氢钙。

The aim of this experiment was to study the effects of low calcium and phosphorus diet supplemented with high dose phytase on growth performance,tibia indexes and calcium and phosphorus metabolism of yellow-feathered chickens aged from 1 to 42 days. One thousand and eighty 1-day-old Lingnan yellow-feathered male chickens were randomly assigned to six groups with six replicates per group and 30 chickens per replicate. Chickens in the positive control group (PC group) fed a basal diet with normal dicalcium phosphate supplementation;chickens in medium calcium and phosphorus levels diet group (MP group) reduced by 50% dicalcium phosphate supplementation,chickens in MP+2000 and MP+4000 groups were supplemented with 2 000 and 4 000 FTU/kg phytase based on MP group,respectively;chickens in low calcium and phosphorus levels diet group (LP group) did not supplement with dicalcium phosphate,chickens in LP+2000 and LP+4000 groups were supplemented with 2 000 and 4 000 FTU/kg phytase based on LP group,respectively. The ratio of calcium to phosphorus remained at 1.4:1.0 in each group. The experiment lasted for 42 days. The results showed as follows: 1) the body weight,average daily gain and average daily feed intake of phytase supplementation groups were significantly higher than those of MP group ( P <0.05),and those of MP+4000 and LP+4000 groups were significantly higher than those of PC group ( P <0.05). 2) The tibia bone density of MP+ 2000 and MP+4000 groups was significantly higher than that of MP group ( P <0.05);the dehydrated and degreased weight of tibia of phytase supplementation groups was significantly higher than that of MP group ( P < 0.05),and that of LP+4000,MP+2000 and MP+4000 groups was significantly higher than that of PC group ( P <0.05);the tibia ash content of LP+2000 and LP+4000 groups was significantly lower than that of MP and PC groups ( P <0.05);the tibia phosphorus and calcium contents of LP+2000 group were significantly lower than those of MP and PC groups ( P <0.05). 3) The serum alkaline phosphatase activity of phytase supplementation groups was significantly lower than that of MP group ( P <0.05). 4) The expression of fibroblast growth factor receptor 1 ( Fgfr1 ) in kidney of MP+4000 group was significantly higher than that of MP and PC groups ( P <0.05). 5) The fecal calcium content of LP+4000 group was significantly lower than that of MP group ( P <0.05),and that of LP+2000 and LP+4000 groups was significantly lower than that of PC group ( P < 0.05);the fecal phosphorus content of LP+2000 and LP+4000 groups was significantly lower than that of MP group ( P <0.05),and that of MP+4000,LP+2000 and LP+4000 groups was significantly lower than that of PC group ( P <0.05);the calcium metabolism rate of LP+4000 group was significantly higher than that of PC group ( P <0.05). In conclusion,low calcium and phosphorus diet supplemented with high dose phytase can improve the growth performance of yellow feathered chickens aged from 1 to 42 days,increased the dehydrated and degreased weight of tibia,reduce the serum alkaline phosphatase activity. Medium calcium and phosphorus diet supplemented with high dose phytase can improve tibia bone density,and up-regulate the expression of Fgfr1 gene in kidney. Only considering the growth performance,serum biochemical indexes,tibia indexes and calcium and phosphorus metabolism index,high dose phytase can be used to partially or completely replace the dicalcium phosphate in the corn-soybean meal of Lingnan yellow feathered chickens aged from 1 to 42 days.