【作者】 姜洁凌；

【导师】 贺建华；

【作者基本信息】 湖南农业大学 ， 动物营养与饲料科学， 2006， 硕士

【摘要】 为了考察饲粮中添加植酸酶对植酸磷利用的影响，确定生长猪的植酸酶磷当量，以便在饲粮配制过程中更合理地评定植酸酶与外源磷的替换关系，本研究从以下方法入手，对玉米-豆粕型日粮中生长猪的植酸酶磷当量进行了研究。 采用单因素试验设计，以有效磷含量0.07％，总磷含量0.37％的玉米-豆粕型日粮为基础日粮，通过NaH₂PO₄·2H₂O向基础日粮中提供外源无机磷和植酸酶，构建4个加磷日粮和3个加酶日粮共8个处理，分别提供0、0.4、0.8、1.2、1.6 g／kg的外源磷和500、750、1000FTU／kg植酸酶，保持各处理组日粮Ca：P=1.33：1。选择96头遗传基础相同，体重22.8±2.2kg的健康杜长大三元杂交生长猪为试验动物，随机分成8个处理组，饲喂以上8种日粮。通过回归分析，根据回归系数R²选择预测方程，建立响应指标（猪趾骨折断强度和趾骨灰分磷含量）与外源磷添加量之间的线性关系，进而确定植酸酶的磷当量值。 试验结果表明： （1） 随着外源磷水平的增加，试验猪生产性能明显改善（P＜0.05），趾骨灰分磷含量和血磷水平都极显著地升高（P＜0.01）；骨骼折断强度显著增大（P＜0.05）。 （2） 基础日粮中添加植酸酶显著提高了生长猪的日增重、骨磷和血磷水平（P＜0.05），并有提高生长猪骨强度的趋势。 （3） 无机磷添加水平与响应指标之间存在较强线性关系[y=10.79x+27.23 x-添加磷（g／kg），y-趾骨强度（kg），R²=0.9221，P＜0.05，n=15；y=1.44x+6.86 x-添加磷（g／kg），y-灰分磷（％），R²=0.9943，P＜0.01，n=15]；植酸酶的磷当量值与日粮中植酸酶和无机磷水平密切相关，同时也受响应指标种类的影响。 （4） 本试验条件下，以趾骨折断强度为响应指标时，每添加500，750，1000FTU／kg日粮的植酸酶可分别等效于添加0.087，0.442和0.720g／kg的无机磷；以趾骨灰分磷含量为响应指标时，每添加500，750，1000FTU／kg日粮的植酸酶可分别等效于添加0.229，0.583，1.063g／kg的无机磷。更多还原

【Abstract】 The objective of present study is to determine the efficacy of P releasing from phytate and determined the phosphorus equivalency of phytase which is the replacement relationship between phytase and inorganic P reasonably during the course of formulation. This study foucus on equivalency value of phytase start with methods desicribled as follows.Method: ninety-six crossbred growing pigs (DurocxLandracexYork) weighted 22.8±2.2kg were alloted to 8 groups of different dietary treatments randomly according to Single Factor Design. Taken corn-soybean as low-P(0.37% total P; 0.07% available P) basal diet, 4 gradual monosodium phosphate(MSP) as well as 3 gradual phytase were supplemented in basal diet to provide 0,0.4, 0.8, 1.2, 1.6 g/kg added P and 500, 750, 1 OOOFTU/kg phytase, respectively. Kept dietary treatment groups Ca:P=1.33:l. Chosen predict equation in terms of R via regression analysis, established the linear relationship between supplemental P and response indicator by determining the bone breaking strength and ash P content, evaluated phytase phosphorus equivalency in regression curve in terms of improvement of response indicator by phytase in diet. The results showed that:1) Animal growing performance and bone breaking strength improved significantly(P<0.05); ash P and serum concentration of inorganic P increased significantly(P<0.01)with increasing levels of MSP.2) Supplemented basal diet with phytase increased average daily gain, ash P and serum P significantly(P<0.05), it also tended to increase the level of bone breaking strength(P>0.05).3) The gradual supplemental P and response indicator fitted well with linear model: y=10.79x+27.23 [x-added P(g/kg); y-metacarpal-metatarsal strength(kg), R~2=0.9221, P<0.05, n=15 or y=1.44x+6.86 x-added P(g/kg); y- ash P(%), R~2=0.9943, P<0.01, n=15]. Phytase phosphorus equivalency of growing pigs was affected not only by P or phytase levels in diets, but also by response indicator.4) The equivalency value calculated from the equation in this study was: 500, 750, 1 000更多还原