Effects of dietary calcium and phosphorus regimen on growth performance, bone strength and carcass quality and yield of large white tom turkeys

Abstract

An experiment was conducted to estimate the calcium (Ca) and nonphytate phosphorus (npP) levels needed for toms in the starter (ST) (3-9 wk of age) and the grower/finisher (G/F) (9-15/15-17 wk of age) periods to support growth performance, bone breaking strength and carcass parameters. After 3 wk of group brooding, poults (B.U.T.) were divided into treatment (trt) pens and fed pellets containing Ca and npP at approximately NRC requirements (3 wk interval basis) or at typical industry (IND) levels (breeder recommendations). At 9 wk of age, birds from each ST trt were fed either a low npP (75% of NRC requirement) diet, the NRC recommended level, or an IND level of npP (Ca:npP=2:1 for all trts) until marketed at 17 wk of age. The birds were weighed every 3 wks and at 17 wk of age. Feed intake was estimated by feed disappearance to calculate feed efficiency. There were 15 pens of 31 birds/pen for each trt in the ST period and 5 pens for each of the 6 trt combinations during the G/F period. Three toms/pen were selected at 15 and 17 wk for bone and component yield measurements. All birds from 3 pens/trt were judged for a walking score (range 1-5, 5 best) during the 17th wk. There was no difference in body weight or feed intake in the ST period. Body weight was decreased when the NRC ST-low npP G/F trt was fed relative to the products in this experiment, especially, for FTM. There was an average moisture reduction of 2.4% for both PBMs and FTMs used in this experiment