Benefit of feeding dietary calcium and nonphytate phosphorus levels above National Research Council recommendations to tom turkeys in the growing-finishing phases

Department of Animal Science, 2209 Anthony Hall, Michigan State University, East Lansing, Michigan 48824, USA. robers22@msu.edu

This experiment evaluated the effects of feeding various dietary Ca and nonphytate P (nPP) levels to Large White male turkeys from 3 to 17 wk of age. After consuming a common prestarter diet, poults were fed approximate NRC (1994) levels of dietary Ca and nPP from 3 to 9 wk of age or levels approximately 25% higher. From 9 to 17 wk of age, each starter group was fed approximately 75 (low P), 100 (medium P), or 145% (high P) of the NRC (1994) requirements for Ca and nPP. Diets were fed as crumbles to 6 wk of age and as pellets from 6 to 17 wk of age. There were no effects on BW or feed efficiency to 9 wk of age. Litter P was increased by 21% when high Ca and nPP were fed from 3 to 9 wk. High dietary Ca and nPP fed during the growing-finishing period generally improved bone strength and ash. Tibia strength and ash were higher in the medium P group compared with in the low P group. Wing bone strength was greater in the high P group than in both the birds fed low or medium P. Litter P was increased by 23% when High P was fed in the growing-finishing period compared to the birds fed the Medium P diet during the same period. The results show there is a benefit to bone strength and mineralization when Ca and nPP are fed at levels higher than NRC (1994) recommendations.