Available phosphorus levels for 95 to 120 kg barrows genetically selected for lean gain

With the objective of evaluating available phosphorus (aP) levels in diets for barrows selected for lean meat deposition, eighty commercial hybrid pigs with initial weight of 94.05±1.05 kg were used in this experiment. Pigs were allotted in a completely randomized block design, with five treatments (0.092, 0.156, 0.220, 0,284, and 0.348% of aP), eight replicates and two pigs per experimental unit. The average daily weight gain of pigs increased and the feed conversion improved quadratically with increasing aP in the diets up to the estimated levels of 0.21 and 0.20%, respectively. There was no effect of the dietary aP on average daily feed intake. However, aP intake, bone strength and concentration of phosphorus in the bones increased linearly with increasing aP in the diets. The levels of aP did not affect carcass traits; however, the alkaline phosphatase activity was improved and the values of serum inorganic phosphorus increased quadratically up to the estimated levels of 0.26 and 0.27% of aP, respectively. The available phosphorus levels of 0.21, 0.27, and 0.35%, corresponding to daily aP intakes of 6.34, 8.13, and 10.44 g result, respectively, in greatest performance, blood and bone parameters of 95 to 120 kg barrows selected for lean gain

Available phosphorus in diets for 15 to 30 kg pigs genetically selected for meat deposition

With the objective to evaluate the effect of dietary available phosphorus levels (aP) on the performance, blood and bone parameters of castrated male and female pigs, genetically selected for meat deposition, 60 commercial hybrids pigs with initial weight of 15.54±0.68 kg were allotted in a completely randomized block design, with six treatments (0.103, 0.210, 0.317, 0.424, 0.531, and 0.638% aP), five replicates, and two animals per experimental unit. Pigs were fed ad libitum and water was provided until the end of the experimental period (21 days), when animals reached 31.31±2.94 kg. Daily weight gain and daily feed intake increased, while the feed conversion improved quadratically up to 0.534, 0.487, and 0.574% aP maximum responses, respectively. The aP intake and the values of inorganic phosphorus in serum increased linearly with increasing the levels of aP in the diets. Alkaline phosphatase activity increased quadratically up to 0.558% maximum response. Bone breaking strength and calcium, phosphorus, and ash contents in the bones increased linearly with increasing aP concentration in the diets. The available phosphorus requirement of castrated male and female pigs genetically selected for meat deposition from 15 to 30 kg for best results of performance is 0.574%, corresponding to a daily intake of 8.26 g of available phosphorus