Efficiency of dietary calcium use for skeletal growth and mineralization in young pigs fed diets with various phosphorus concentrations

16 p.Nutrient efficiencies are generally greater for animals fed diets with marginal deficiencies. In a preliminary study, however, Ca efficiency was lower in pigs fed diets with a marginal Ca deficiency (J Bone Miner Re 20:S193). The study assessed recovery of skeletal growth in young pigs following a period of Ca-deficiency. The Ca efficiency may have been inadvertently limited by the P concentrations in the diet. This study is designed to assess the effects of 70, 90, 120% of NRC P requirements on Ca efficiency for 75% and 150% of Ca levels. The Ca efficiencies were estimated using BMC values obtained from DXA Scans. Pigs fed 70% P did not gain bone mass over 27 d trials, regardless of Ca level, and pigs fed 120% did not show significant differences in Ca efficiency. Pigs fed 90%, however, exhibited effects that support Ca efficiencies being greater for marginally deficient diets (75% Ca