ABSTRACT
The objective of this study was to evaluate sequential digestible phosphorus levels for gilts from 30 to 100 kg. Sixty gilts were used, with an initial weight of 29.98±3.37 kg and final weight of 100.66±8.82 kg, distributed in a randomized block design, with five nutritional digestible phosphorus levels: 2.19-1.88-1.68, 2.69-2.38-2.18, 3.19-2.88-2.68, 3.69-3.38-3.18, and 4.19-3.88-3.68 g kg−1, respectively, for the growth phases 30 to 50 kg, 50 to 70 kg, and 70 to 100 kg, with six replicates and two animals per pen. The nutritional plans did not influence the final weight, days to reach 100 kg, total and daily weight gain, total and daily feed intake, crude protein intake, digestible lysine intake, or metabolizable energy intake. An increase in digestible phosphorus and calcium intake was observed according to the increase in the digestible phosphorus level in the diet. There was a significant effect on feed conversion. No effect of nutritional plans was observed for backfat thickness, muscle depth, loin eye area, lean meat percentage, or carcass bonus index. There was no difference in the production of dry and natural matter or the residue coefficient. The effect of the nutritional digestible phosphorus levels in the contents of total solids and volatile solids was verified. There was a difference in the concentration of total nitrogen and total phosphorus in the manure. The nutritional plan with 3.19-2.88-2.68 and 3.69-3.38-3.18 g kg−1 of digestible phosphorus results in better feed conversion than the basal diet. For a lower excretion of phosphorus in the manure, the recommended nutritional plan is 2.19-1.88-1.68 g kg−1 of digestible phosphorus.
Keywords:
carcass quality; manure; mineral supplementation