Cromwell G L, Stahly T S, Coffey R D, Monegue H J, Randolph J H
Department of Animal Sciences, University of Kentucky, Lexington 40546.
J Anim Sci. 1993 Jul;71(7):1831-40. doi: 10.2527/1993.7171831x.
Four experiments involving 225 pigs were conducted to assess the efficacy of a microbial phytase (FINASE, Alko Ltd. Biotechnology, Rajamäki, Finland) produced by Aspergillus niger in corn-soybean meal or dextrose-cornstarch-soybean meal-based diets. In two experiments with growing-finishing pigs, fortified corn-soybean meal diets were formulated to be adequate (.50%) or inadequate (.40 or .30%) in P during the growing phase followed by adequate (.40%) or inadequate (.30%) P in the finishing phase. Mono-dicalcium phosphate was the source of supplemental P. Half the diets were supplemented with phytase (500 phytase units/g). Rate and efficiency of gain and bone breaking strength were decreased when P-deficient diets were fed. Phytase supplementation of the low-P diets restored growth rate and feed:gain to levels that approached those of pigs fed the adequate-P control diet. Bone strength was partially restored to that of the controls. In two additional experiments, pigs were fed low-P basal diets in which all the dietary P came from soybean meal or a corn-soybean meal blend. Both diets contained .05% available P. Graded levels of monosodium phosphate were added to these diets, up to .15% added P, to establish a standard curve. Phytase was added to the basal diet at 250, 500, or 1,000 units/g. Growth rate and bone strength improved linearly (P < .01) with added monosodium phosphate and with increasing levels of supplemental phytase. Based on estimates of total and available P intakes, the highest level of phytase (1,000 units/g) increased the bioavailability of the P from 25% in the soybean meal diet to 57% in the phytase-supplemented diet, and from 15% in the corn-soybean diet to 43% in the phytase-supplemented diet. Expressed on the basis of the improvement in phytate P availability, this level of phytase converted approximately one-third of the unavailable P to an available form. The results indicate that the phytase was efficacious in improving the bioavailability of phytate P for pigs.
开展了四项涉及225头猪的试验，以评估由黑曲霉产生的一种微生物植酸酶（FINASE，芬兰拉亚迈基阿尔科有限公司生物技术部）在玉米 - 豆粕型或葡萄糖 - 玉米淀粉 - 豆粕型日粮中的效果。在两项针对生长育肥猪的试验中，配制的强化玉米 - 豆粕型日粮在生长阶段的有效磷含量设定为充足（0.50%）或不足（0.40%或0.30%），随后在育肥阶段的有效磷含量为充足（0.40%）或不足（0.30%）。磷酸二氢钙是补充磷的来源。一半的日粮添加了植酸酶（500植酸酶单位/克）。饲喂低磷日粮时，生长速度、生长效率和骨骼断裂强度均下降。给低磷日粮添加植酸酶可使生长速度和饲料转化率恢复到接近饲喂充足磷对照日粮猪的水平。骨骼强度部分恢复到对照水平。在另外两项试验中，给猪饲喂低磷基础日粮，其中所有日粮磷均来自豆粕或玉米 - 豆粕混合物。两种日粮的有效磷含量均为0.05%。向这些日粮中添加不同水平的磷酸一钠，添加磷最高达0.15%，以建立标准曲线。在基础日粮中添加250、500或1000单位/克的植酸酶。随着磷酸一钠添加量的增加以及植酸酶添加水平的提高，生长速度和骨骼强度呈线性改善（P < 0.01）。根据总磷摄入量和有效磷摄入量的估计，最高水平的植酸酶（1000单位/克）可使豆粕型日粮中磷的生物利用率从25%提高到添加植酸酶日粮中的57%，使玉米 - 豆粕型日粮中磷的生物利用率从15%提高到添加植酸酶日粮中的43%。以植酸磷利用率的提高为基础来表示，该水平的植酸酶可将约三分之一的不可利用磷转化为可利用形式。结果表明，该植酸酶在提高猪对植酸磷的生物利用率方面是有效的。
