Effects Of Dietary Phosphorus Level And Phosphorus Sources On Growth Performance And Tibia Quality Of Finishing Pigs

The purpose of this experiment is to study the effect of the dietary phosphorus sources and phosphorus levels on growth performance, serum biochemical indicators and bone performance of finishing pig. Explore the optimal phosphorus sources and the appropriate level in the diets of finishing pig. Forty finishing pigs (Landrance×Yorkshire) with body weight (BW) of64.57±4.06kg were randomly allotted into five dietary treatments and each treatment had four replicates comprising two pigs. Four treatments were provided corn-soybean experimental diets supplemented with0.7%、0.58%、0.5%0.58%phosphorus and0.7%calcium. But the phosphorus sources,one of the four treatments, was calcium hydrogen phosphate,The others were calcium dihydrogen phosphate Neverthe-less.the other treatment was supplemented with0.9%calcium and0.75%phosphorus,The adjustment period lasted for3days and the experimental period lasted for42days. The results showed as follows:Growth proformance:When the phosphorus source and the calcium levels were the same, the effects of different phosphorus levels on average daily feed consumption, average daily gain, feed to gain ratio difference were not significant (P>0.05);The same phosphorus source with high levels of calcium and phosphorus group had not significant (P>0.05) effects on average daily feed consumption, average daily gain, feed to gain with low levels of calcium and phosphorus;When the levels of calcium and phosphorus were same with different Phosphorus source, calcium dihydrogen phosphate group has no significant difference (P>0.05), on average daily feed consumption, average daily gain, feed to gain ratio with the dicalcium phosphate group.Blood bioehemieal index:When the phosphorus source and the calcium levels were the same,as the dietary phosphorus level gradually decreased, serum phosphorus content was decreased (P<0.05), and the second week serum phosphorus content showed a downward trend(P=0.083), The phosphorus level of0.7%was significantly higher than the phosphorus level of0.58%and0.5%in the fourth week(P<0.05). The serum phosphorus of the sixth week was no significant difference (P>0.05). With dietary phosphorus levels dropped from0.7%to0.58%, the serum calcium concentration was increased, the phosphorus levels of0.5%were significantly higher than the0.7%phosphorus level group in the Sixth week (P <0.05); the0.5%phosphorus level group and0.58%phosphorus level group tended to increase (p=0.078).The serum calcium content on the second week and the fourth week were not significant difference (P>0.05). The different phosphorus levels has no significant difference (P>0.05)on serum alkaline phosphalase activityWhen the phosphorus source was same,the high calcium and phosphorus groups had highcr serum calcium content than the low-calcium phosphate group in the sixth week(P <0.05),. The serum phosphorus content of hige calcium and phosphorus groups had downward trend compared with low-calcium phosphate groups (P=0.056);The serum alkaline phosphatase content were no significant difference (P>0.05).When the phosphorus Source was different but the levels of calcium and phosphorus were same:the serum calcium content in DCP groups were significantly higher than calcium dihydrogen phosphate groups in the sixth week (P<0.05), the serum calcium content in second week andthe fourth week were no significant difference (P>0.05). The serum phosphorus content in fourth week of DCP was significantly higher than calcium dihydrogen phosphate group (P<0.05); the serum alkaline phosphatase activity was no significant difference (P>0.05).Skeleton index:When the phosphorus source and calcium levels are the same,as the dietary phosphorus level gradually decreased the calcium and phosphorus content of bone first increased, then decreased, the calcium and phosphorus of bone content was maximum when the phosphorus level was0.58%and the calcium:phosphorus was1.2:1, the calcium content of third metacarpal,fourth metacarpal, third metatarsal、fourth metatarsal and humerus were not significant difference (P>0.05),A11bone phosphorus content was not significant (P>0.05). Bone tensile force decreased with the decline in the level of phosphorus, but there was no statistically significant difference (P>0.05).The third metacarpal, third metatarsal, fourth metatarsal, humerus, femur of high levels of calcium and phosphorus groups were significantly lower than the low-calcium phosphate group in the bone meal calcium content (P<0.05); the femoral of the high calcium phosphate was significantly lower than the low-calcium phosphate group in the bone meal phosphorus content (P<0.05); the humerus bone tensile force of high calcium phosphate groups were significantly lower than the low-calcium phosphate group (P<0.05). When the levels of calcium and phosphorus are same,but the phosphorus Source was different, the calcium content and phosphorus content of calcium dihydrogen phosphate group was significantly higher than the the dicalcium phosphate group in shares and humerus,(P<0.05).Between the different source of phosphorus, calcium dihydrogen phosphate group of the third metacarpal, the fourth metacarpal bone, humerus, femur bone pull off force is less than the calcium hydrogen phosphate group, but there was not significant difference (P>0.05).Conclusion:In this experimental,the calcium and phosphorus content of bone were more than calcium hydrogen phosphate group compared with calcium dihydrogen phosphate groups. The bone pull-off force of calcium hydrogen phosphate group was better than calcium dihydrogen phosphate group,When the phosphorus Source is calcium dihydrogen phosphate,and the phosphorus levels is0.58%,60-100Kg fattening pigs indicators were best, high calcium phosphate group is not conducive to the deposition of boned calcium and phosphorus.