可消化钙水平对饲喂不同磷含量日粮生长猪生长性能和骨成分的影响

Effects of digestible calcium levels on growth performance and bone composition of pigs fed with different phosphorus contents diets

本研究开展了30 d的饲养试验以确定可消化钙水平对饲喂不同磷含量日粮生长猪生长性能和骨成分的影响。试验选择平均体重为(50.21±2.1)kg的生长猪180头,随机分为15组,每组12头猪,每个重复4头猪。试验日粮采用3×5因子设计,可消化磷水平分别为1.4、2.7、4.1 g/kg,可消化钙水平分别为1.3、2.5、3.8、5.0,和6.3 g/kg。结果表明,日粮可消化钙和可消化磷水平对生长猪末重、日增重、饲料报酬、骨钙和骨磷含量的影响具有显著交互作用(P<0.05)。在可消化钙磷比值分别为1.20∶1和1.25∶1,可消化磷水平为2.7 g/kg时,预测的最大体重为87.20 kg,日增重为1.23 kg。但由于方程的线性性质,没有得到预测的最大饲料报酬。随着日粮可消化钙水平的增加,无论饲粮中可消化磷水平是多少,平均日采食量均表现为显著降低(P<0.05)。可消化磷含量为2.7和4.1 g/kg时,预测的骨骼灰分最大值分别为55.8和60.1 g/kg,对应的可消化钙磷比值分别为2.03∶1和1.59∶1。综上所述,当日粮磷水平达到或低于需要水平时,过量的钙对50~85 kg猪生长性能具有负面影响。而当可消化钙水平高于需要水平时,饲粮中含有高于需要水平的可消化磷可以使猪的生长性能最大化。骨灰分最大化所需的可消化钙水平大于生长性能最大化需要的可消化钙水平,同时当磷水平达到需要量时,保证足够的骨矿化而不影响生长性能所需的可消化钙磷比为1.23∶1。

A 30-day feeding trial was conducted to determine the effect of digestible calcium levels on growth performance and bone composition in pigs fed diets with different phosphorus contents.A total of 180 growing pigs with an average weight of(50.21±2.1)kg were selected and randomly divided into 15 groups with 12 pigs per group(4 pigs/repeat).The digestible phosphorus levels were 1.4,2.7,and 4.1 g/kg,respectively,and the digestible calcium levels were 1.3,2.5,3.8,5.0,and 6.3 g/kg,respectively.The results showed that dietary digestible calcium and phosphorus levels had significant interaction effects on the final weight,daily weight gain,feed efficiency,bone calcium and bone phosphorus contents of growing pigs(P<0.05).When the digestible calcium-phosphorus ratio was 1.20∶1 and 1.25∶1,respectively,and the digestible phosphorus level was 2.7 g/kg,the predicted maximum weight was 87.20 kg and the daily weight gain was 1.23 kg.However,due to the linear nature of the equation,the predicted maximum feed return is not obtained.With the increase of dietary digestible calcium level,the mean daily feed intake was significantly reduced regardless of the digestible phosphorus level in the diet(P<0.05).When the digestible phosphorus content was 2.7 and 4.1 g/kg,the maximum predicted bone ash content was 55.8 and 60.1g/kg,respectively,and the corresponding digestible calcium-phosphorus ratios were 2.03∶1 and 1.59∶1,respectively.In conclusion,when the dietary phosphorus level reached or below the required level,excessive calcium had a negative impact on the growth performance of 50~85 kg pigs.However,when the digestible calcium level is higher than the required level,the presence of digestible phosphorus in the diet can maximize the growth performance of pigs.The digestible calcium level required for maximum ashes content is higher than the digestible calcium level required for maximum growth performance.At the same time,when the phosphorus level reaches the required amount,the digestible calcium and phosphorus ratio required to ensure sufficient bone mineralization without affecting growth performance is 1.23∶1.