微生物植酸酶对猪钙、磷利用率及骨骼发育的影响

本试验旨在研究从断奶到肥育结束,在饲粮中添加微生物植酸酶对猪钙、磷代谢及骨骼发育的影响。试验采用完全随机设计,将72头35日龄断奶的仔猪分为4组,每组3个重复,每个重复6头。试验在相同钙水平基础上设4个组,分别为:1)玉米-豆粕基础日粮(对照组);2)基础日粮 植酸酶-50%磷酸氢钙(处理1);3)基础日粮 植酸酶-75%磷酸氢钙(处理2);4)基础日粮 植酸酶-100%磷酸氢钙(处理3)。试验期按体重分3个阶段:8~20 kg、20~50 kg、50~90 kg,3个阶段植酸酶的添加量分别为750、500和250 U/kg。试验结果表明:(1)在8~20 kg和20~50 kg阶段,添加植酸酶的3个处理,钙、磷消化率显著高于对照组(P<0.05);血钙和血磷浓度,处理1和处理2与对照组无显著差异(P>0.05),处理3显著低于对照组(P<0.05)。在50~90 kg阶段,添加250 U/kg植酸酶代替100%磷酸氢钙,血磷、血钙浓度显著低于对照组(P<0.05);(2)在试验的3个阶段添加植酸酶同时降低饲粮无机磷水平,对血清碱性磷酸酶活性均无显著影响(P>0.05);(3)添加植酸酶使胃中植酸磷消化率显著提高(P<0.0 1),粪中磷排出量显著降低(8~2 0 kg、2 0~5 0 kg阶段,P<0.0 1;5 0~9 0 kg阶段,P<0.0 5);(4)添加植酸酶代替50%或75%磷酸氢钙,猪的掌骨灰分与采食正常磷日粮的对照组无显著差异,但代替100%磷酸氢钙组,猪的掌骨灰分和蹠骨强度则显著低于对照组(P<0.05);添加植酸酶代替50%磷酸氢钙组,猪的蹠骨强度显著高于对照组(P<0.05),代替75%磷酸氢钙组与对照组差异不显著(P>0.05)。总之,在断奶和生长阶段,在猪玉米-豆粕日粮中添加植酸酶可代替部分磷酸氢钙,促进了钙、磷消化利用,促进了骨骼生长,也促进了植酸磷的利用,降低了粪磷排出。

Effect of Dietary Phytase Supplementation on Availability of Ca, P and Bone Development in Pigs

The effects of supplementing microbial phytase into diet during the period of weaning and finishing in pig on the metabolis m of Ca,P and bone development were studied in this paper.Seventy-two healthy piglets weaned at 35-day old were divided into four groups with three replicates and six piglets in each replicate randomly.The experi ment was done at the same Ca level.Four treat ments were arranged as follows : 1) the control group:corn-soybean meal basal diet(CSBM);2) Treat ment 1 : CSBM basal diet plus phytase substituting 50 % CaHPO4of the diet;3) Treat ment 2 : CSBM basal diet plus phytase substituting 75 % CaHPO4of the diet;4) Treat ment 3 : CSBMbasal diet plus phytase substituting 100 % CaHPO4of the diet.The experi ment was divided into three stages based on the body weight of pig,which were the stages of 8 ~20 kg,20 ~50 kg and 50 ~90 kg.The doses of phytase supplementation were 750 U/kg,500 U/kg and 250 U/kg for the stages of 8 ~20 kg,20 ~50 kg and 50 ~90 kg,respectively.The results showed the following results.1) During the periods of 8 ~20 kg and 20 ~50 kg,the digestibility of Ca and P of the treat ments added phytase was significantly higher thanthat of the control group(P<0.05).The concentration of serum Ca and serumPin Treat ment 3 was significantlylower than that of the control group(P<0.05),whereas there were no significant differences among Treat ment 1,Treat ment 2 andthe control group(P>0.05).Inthe period of 50 ~90 kg,the concentration of serum Ca andserum P significantly decreasedin Treat ment 3 compared withthat of control group(P<0.05);2) Phytase supplementation and decreasing the Pconcentration of the diet si multaneously had nosignificant effect onthe activity of the serumalkaline phosphatase during the whole experi ment(P>0.05);3) The digestibility of phytate Pin the stomach significantly increased(P<0.01),and the amount of P excretion decreased due to the phytase supplementation(8 ~20 kg and 20 ~50 kg period,P<0.01;50 ~90 kg period,P<0.05);4) There was no significant difference in metacarpal bone ash among Treat ment 1,Treat ment 2 and control group,whereas the metacarpal bone ash andthe metatarsal bone strengthin Treat ment 3 were significantlylower thanthat of control group.The metatarsal bone strengthin Treat ment 1 was significantly higher thanthat of control group(P<0.05),and there was no significant difference between Treat ment 2 and control group(P>0.05).In a word,the digestion and utilization of the Ca,P,phytate P,and the development of the bone were improved,and the excretion of P de-creased by supplementing phytase to instead of part of CaHPO4in the cornsoybean basal diet during the periods of 8 ~20 kg and 20 ~50 kg in pigs.