在含粗小麦粉的生长育成期猪日粮中添加植酸酶的效果

The Effects of Phytase Supplementation to Growing-Finishing Diets Containing Wheat Middlings

试验采用 5 4头杂交猪 (初始体重为 2 8.4± 0 .98kg)来评估在含粗小麦粉的生长育成日粮中添加植酸酶的效果。试验猪被随机分成 2组 :对照组和试验组。试验组日粮除了以每千克 5 0 0单位的植酸酶取代相应的无机磷以外 ,其它成分与对照组日粮相同。试验期分 3个日粮阶段 ,采用 Cr2 O3 为外源指示剂来测定营养成分的消化率 ,每 2周测定 1次猪的体重和采食量并计算饲料效率。在第 2和第 3个日粮阶段分别为 7d的 2个采样期中 ,每天随机采取猪的粪样并按栏混合 ,然后对粪样的干重以及 Ca、P、Cu、Zn的含量分别进行测定。试验结果表明 ,试验组和对照组之间无论是平均日增重还是平均日采食量均没有显著差异。 5～ 8周间对照组的料肉比高于试验组 ( P<0 .0 5 ) ,但在其它各阶段均无显著差异。干物质消化率在第 2日粮阶段中无显著差别 ,但在第 3阶段中试验组高于对照组 ( P<0 .0 1 )。 Ca的消化率也同样是在第 2阶段中 2组相似 ,但在第 3阶段中试验组高于对照组 ( P<0 .0 1 )。磷 ( P)的消化率则无论在第 2阶段 ( P<0 .0 5 )还是第 3阶段 ( P<0 .0 1 ) ,均是试验组高于对照组。试验结果表明 ,在含粗小麦粉的生长育成猪日粮中添加植酸酶可以达到同直接添加无机磷一样的效果。

An experiment was conducted using 54 crossbred pigs(initial wt of 28.4±0.98 kg) to evalute the efficacy of phytase addition to grower-finisher diets containing wheat middlings. Pigs were randomly allotted to either a control ration or an equivalent diet with 500 PU/kg of phytase added to the expense of an inorganic phosphorus source. There were three dietary phases during the experimental period. All diets contained an indigestible marker(chromic oxide) for determination of nutrient digestibility. Pigs were weighed, feed intakes were recorded, and feed efficiency was calculated every two weeks. Random fecal samples, pooled by pen, were obtained during two 7-d collection periods during dietary phases 2 and 3. Fecal samples were analyzed for dry matter, calcium, phosphorus, copper and zinc concentrations, and digestibility estimates were obtained by use of the indicator method. Neither ADG nor ADFI were different between the two dietary treatments during the trial. Gain per feed ration was greater for control animals than phytase supplemented pigs during wk 5～8(P<0.05),however, did not differ during any other point during the trial. Dry matter digestibility was not different during phase 2, but was higher for pigs fed diets supplemented with phytase during phase 3(P< 0.01). Digestibility of calcium was similar during phase 2, but was higher in pigs fed phytase during phase 3(P<0.01). Phosphorus digestibility was greater for pigs fed phytase-supplemented diets during both phase2(P<0.05)and phase 3(P<0.01). Phytase addition to diets containing wheat middlings enables growing- finishing pigs to have comparable growth performance to pigs fed diets containing wheat middling with inorganic phosphorus. The addition of phytase enables release and absorption of both calcium and phosphorus in diets containing wheat middlings. resulting in a lower concentration of these minerals in the excrement.