饲粮磷水平对泌乳水牛泌乳性能、磷消化代谢和血液指标的影响

Effects of Dietary Phosphorus Levels on Lactation Performance,Phosphorus Digestion and Metabolism and Blood Indices of Lactating Buffaloes

本试验旨在研究饲粮磷水平对泌乳水牛泌乳性能、磷消化代谢和血液指标的影响。选择体况良好、胎次相似、泌乳3个月左右以及泌乳量大致相等的32头健康水牛,按体重随机分成4组,每组8头水牛,每个重复1头牛。4组分别饲喂磷水平为0.30%、0.39%、0.48%和0.57%的饲粮,饲粮其他营养水平保持一致。试验期35 d,包括14 d的预试期和21 d的正试期。在正试期的最后5 d,每组随机选取3头水牛,采用全粪尿收集法进行消化代谢试验。结果表明:1)饲粮磷水平对泌乳水牛日均产奶量、4%标准乳产量、乳蛋白率、乳脂率、乳非脂乳固形物率、乳钙含量和乳磷含量均无显著影响(P>0.05),其中0.39%磷水平组4%标准乳产量最高。2)饲粮磷水平显著影响泌乳水牛食入磷、粪磷、总排泄磷和可利用磷含量(P<0.05),且上述指标随饲粮磷水平的提高呈上升趋势;饲粮磷水平显著影响泌乳水牛中性洗涤纤维(NDF)表观消化率、磷表观消化率、粪磷占食入磷比例和乳磷占食入磷比例(P<0.05),其中0.48%磷水平组NDF表观消化率显著高于其他3组(P<0.05),0.30%磷水平组磷表观消化率显著低于其他3组(P<0.05),0.39%磷水平组粪磷占食入磷比例显著高于其他3组(P<0.05),0.48%磷水平组乳磷占食入磷比例显著低于其他3组(P<0.05)。3)饲粮磷水平显著影响泌乳水牛血液磷含量和血清碱性磷酸酶(ALP)活性(P<0.05),其中血液磷含量随饲粮磷水平的提高呈升高趋势,血清ALP活性随饲粮磷水平的提高呈降低趋势。综上所述,综合泌乳性能、磷消化代谢和血液指标并考虑磷排泄和环境污染的情况下,以0.39%磷水平组泌乳水牛饲喂效果较好,建议泌乳水牛饲粮磷水平以0.39%为宜。

This experiment was conducted to investigate the effects of dietary phosphorus levels on lactation performance,phosphorus digestion and metabolism and blood indices of lactating buffaloes.Thirty-two healthy buffaloes with good body condition,similar parity,about 3 months of lactation and roughly equal milk output were randomly divided into 4 groups according to body weight with 8 buffaloes in each group and 1 buffalo in each replicate.The buffaloes in the four groups were fed diets with phosphorus levels of 0.30%,0.39%,0.48%and 0.57%,respectively,and the other nutrient levels were consistent.The experiment lasted for 35 days,including 14 days of pre-trial period and 21 days of trial period.In the last 5 days of the trial period,3 buffaloes in each group were randomly selected to perform digestion and metabolism tests by total feces and urine collection method.The results showed as follows:1)dietary phosphorus levels had no significant effects on the average daily milk yield,4%fat correction milk yield,milk protein rate,milk fat rate,milk non-fat milk solid rate,milk calcium content and milk phosphorus content of lactating buffaloes(P>0.05),and the 4%fat correction milk yield in 0.39%phosphorus level group was the highest.2)Dietary phosphorus levels significantly affected the contents of intake phosphorus,fecal phosphorus,total phosphorus excretion and available phosphorus of lactating buffaloes(P<0.05),and the above indices were increased with the increase of dietary phosphorus level;dietary phosphorus levels significantly affected the neutral detergent fiber(NDF)apparent digestibility,phosphorus apparent digestibility,fecal phosphorus to phosphorus intake ratio and milk phosphorus to phosphorus intake ratio of lactating buffaloes(P<0.05),the NDF apparent digestibility in 0.48%phosphorus level group was significantly higher than that in the other 3 groups(P<0.05),the phosphorus apparent digestibility in 0.30%phosphorus level group was significantly lower than that in the other 3 groups(P<0.05),the fecal phosphorus to phosphorus intake ratio in 0.39%phosphorus level group was significantly higher than that in the other 3 groups(P<0.05),and the milk phosphorus to phosphorus intake ratio in 0.48%phosphorus level group was significantly lower than that in the other 3 groups(P<0.05).3)Dietary phosphorus levels significantly affected the blood phosphorus content and serum alkaline phosphatase(ALP)activity of lactating buffaloes(P<0.05),in which the blood phosphorus content was increased with the increase of dietary phosphorus level,and the serum ALP activity was decreased with the increase of dietary phosphorus level.In conclusion,combining lactation performance,phosphorus digestion and metabolism,and blood indices,and considering phosphorus excretion and environmental pollution,the feeding effects on lactating buffaloes in 0.39%phosphorus level group is better,and it is recommended that the dietary phosphorus level for lactating buffaloes should be 0.39%.