Effects Of Different Dietary Calcium Andphosphorus Levels And Their Ratio On Growth Performance, Nutrient Digistibility And Serum Index In Shanbei White Cashmere Weaning Goats

The study was conducted to evaluate effects of different dietary of calcium and phosphorus levels and their ratio on growth performance, nutrient digestion and serum index of Shanbei White Cashmere weaning goats. Four different dietary calcium and phosphorus levels diets, including two calcium levels(0.80%, 0.65%) and two phosphorus levels(0.60%, 0.45%), were provided to Shanbei White Cashmere weaning goats. This research included four experiments:Experiment 1: Effects of different dietary of calcium and phosphorus levels on growth performance in Shanbei White Cashmere weaning goats.Thirty-six goats were randomly assigned to four groups, and each group had three repeats with three goats. The goats were fed with the diets of four different levels of calcium and phosphorus at 8:00 and 16:00. The body weight of goats was measuredmonthly. The results showed that calcium and phosphorus supplementation in the basal diet had no significantly influence on DMI, but affected ADG and the feed conversion efficiencies of animals remarkably, ADG of group of the highest Ca and P levels was significantly higher than others(P<0.05).The optimal dietary different levels of calcium and phosphorus level were 0.8% and 0.45%-0.65% respectively according to growth performance.Experiment 2: Effects of different dietary of calcium and phosphorus levels on digestibility and ME and nitrogen in Shanbei White Cashmere weaning goats.Twelve goats from 12 repeats were used to determine the influence on digestibilityof ME and nitrogen. The results showed that dietary Ca and P levels had significantly influence on not only total apparent digestibility of energy, but also retained nitrogen. Optimal dietary levels of calcium and phosphorus level can promote the utilization with energy and nitrogen. The optimal dietary different levels of calcium and phosphorus level were 0.8% and 0.45% respectively.Experiment 3: Effects of different dietary of calcium and phosphorus levels on serum index in Shanbei White Cashmere weaning goats.Blood samples of 12 goats were collected every fifteen days to test the concentration of calcium, phosphorus,alkaline phosphorous, parathyroid hormone, calcitonin 1,25-dihydroxy Cholecalciferol. The results showed that calcium and phosphorus supplementation in the basal diet had no significantly influence on serum Ca concentration, but had significantly influence on serum AKP, PTH, CT, DCC concentration.The optimal dietary different levels of calcium and phosphorus level were 0.8% and 0.45% respectively. Experiment 4: Effects of different dietary of calcium and phosphorus levels on digestibility and metabolism of Ca and P of Shanbei white Cashmere weaning goats.Twelve goats from 12 repeats were used to determine the influence on digestion and metabolism of Ca and P.The results showed that calcium and phosphorus supplementation in the basal diet had significantly influence on intake Ca or P, excretion Ca or P and deposited Ca or P(P<0.05).The relationships between intake Ca or P and excretion Ca or P were showed in the following regression equations for Ca, Y=0.662X+0.929(R2=0.993; n=4) and for P, Y=0.776X+0.506(R2=0.996;n=4), the Ca and P maintenance requirements of cashmere weaning goats were 0.929 g/d and 0.506 g/d respectively. The relationships between deposited Ca or P and ADG were showed in the following regressionequations for Ca, Y=47.737X-21.622(R2=0.649;n=4) and for P, Y=94.50X-35.39(R2=0.831; n=4).In summary, the optimal dietary different levels of calcium and phosphorus level was 0.8% and 0.45% respectively by digestibility and metabolism experiment, and the relationships between deposited Ca or P and ADG were showed in the following regression equations for Ca, Y=47.737X-21.622(R2=0.649;n=4) and for P, Y=94.50X-35.39(R2=0.831; n=4) in Shanbei White Cashmere weaning goat.