Combs N R, Kornegay E T, Lindemann M D, Notter D R
Virginia Polytechnic Institute and State University, Blacksburg 24061.
J Anim Sci. 1991 Feb;69(2):673-81. doi: 10.2527/1991.692673x.
Three trials using 300 pigs were conducted to establish response surfaces for effects of calcium and phosphorus (Ca/P) levels and of time on postweaning pig performance. Five dietary Ca/P levels (70, 85, 100, 115 and 130% of the NRC [1979] estimated dietary Ca and P requirements) were fed from weaning to market weight. Twelve replicates, each consisting of five pigs, were used across the three trials, and one pig per replicate was slaughtered every 4 wk following the start of the trials. Efficiency of feed utilization (G:F) was insensitive to diet within the range of Ca/P levels used, whereas ADG and average daily feed intake (ADFI) were linearly (P less than .01) and quadratically (p less than .01) related to both diet and weigh period. Asymptotic models relating continuous effects of total Ca + P intake (average grams per day of Ca + P) relative to the NRC estimated Ca + P intake and days on test at the midpoint of each weigh period were fitted to the data and used to derive response surfaces for ADG and ADFI. Ninety, ninety-five and ninety-eight percent of maximum ADG, ADFI and G:F also were determined; 98% of maximum ADG was reached with a Ca and P intake of 99.8% of NRC Ca/P estimates, whereas Ca and P intakes of 95.3 and 83.5% of NRC estimates were required to produce 98% of maximum ADFI and G:F, respectively.
进行了三项使用300头猪的试验，以建立钙磷（Ca/P）水平和时间对断奶仔猪生长性能影响的响应面。从断奶到上市体重期间，饲喂五种日粮Ca/P水平（分别为NRC[1979]估计日粮钙和磷需求量的70%、85%、100%、115%和130%）。三项试验共使用了12个重复，每个重复包含5头猪，试验开始后每4周屠宰每个重复中的1头猪。在所使用的Ca/P水平范围内，饲料利用率（G:F）对日粮不敏感，而平均日增重（ADG）和平均日采食量（ADFI）与日粮和称重期均呈线性（P<0.01）和二次曲线（P<0.01）相关。将总钙+磷摄入量（每天钙+磷的平均克数）相对于NRC估计的钙+磷摄入量的持续效应以及每个称重期中点的试验天数的渐近模型拟合到数据中，并用于推导ADG和ADFI的响应面。还确定了最大ADG、ADFI和G:F的90%、95%和98%；当钙和磷摄入量达到NRC钙/磷估计值的99.8%时，达到最大ADG的98%，而分别需要NRC估计值的95.3%和83.5%的钙和磷摄入量才能产生最大ADFI和G:F的98%。
