Effects of Dietary Phosphorus Level on Growth Performance,Nutrient Apparent Digestibility and Phosphorus Excretion of Growing Dairy Buffaloes
The aim of this experiment was to study the effects of dietary phosphorus level on the growth per-formance,nutrient apparent digestibility and phosphorus excretion of growing dairy buffaloes.Twenty-four healthy 11-month-old dairy buffaloes with similar body weight were selected and randomly divided into four groups of six buffaloes each,with one replication per buffalo,and fed experimental diets with phosphorus level of 0.21％,0.24％,0.27％and 0.30％,respectively,and other nutrient levels of the experimental diets were maintained at the same level.The total experimental period was 52 days,including a 10-day pre-feeding period and a 42-day formal trial period.Three buffaloes were randomly selected from each group for a 5-day digestive metabolism test during the last 5 days of the formal trial period.The results showed as follows:1)dietary phosphorus level had no significant effects on the initial body weight,final body weight,dry matter intake and average daily gain of growing dairy buffaloes(P＞0.05),but had a significant effect on the feed-to-gain ratio(P＜0.05),the feed-to-gain ratio of 21％phosphorus level group was significantly higher than that of other 3 groups(P＜0.05).2)Dietary phosphorus level had significant effects on the apparent digestibility of dry mat-ter,crude protein and phosphorus(P＜0.05).The apparent digestibility of dry matter,crude protein,calcium and phosphorus in the 0.27％phosphorus level group was the highest among the four groups.3)Dietary phos-phorus level had significant effects on phosphorus intake,fecal phosphorus,urine phosphorus,total phosphor-us excretiona and phosphorus excretion per kilogram of metabolic body weight(P＜0.05).4)The linear re-gression equation of phosphorus intake(X,g/d)and phosphorus excretion per kilogram of metabolic body weight[Y,g/(kg W0.75·d)]for growing dairy buffaloes was Y=0.009 1X+0.044 7(R2=0.954 1),and the phosphorus maintenance requirement for growing dairy buffaloes was 0.13 g/(kg W0.75·d)according to the regression equation.In conclusion,dietary phosphorus level for growing dairy buffaloes is appropriate at 0.27％in combination with the growth performance,nutrient apparent digestibility and phosphorus excretion.[Chinese Journal of Animal Nutrition,2024,36(12):7799-7808]
万方数据
维普
