Meta-analysis of phosphorus utilization by growing pigs: effect of dietary phosphorus, calcium and exogenous phytase

M. P. Létourneau-Montminy, C. Jondreville, D. Sauvant, A. Narcy
2012 Animal  
Optimizing phosphorus (P) utilization in pigs requires improving our capacity to predict the amount of P absorbed and retained, with the main modulating factors taken into account, as well as precisely determining the P requirements of the animals. Given the large amount of published data on P utilization in pigs, a meta-analysis was performed to quantify the impact of the different dietary P forms, calcium (Ca) and exogenous phytases on the digestive and metabolic utilization criteria for
more » ... n criteria for dietary P in growing pigs. Accordingly, the amount of phytate P (PP) leading to digestible P (g/kg) was estimated to be 21%, compared with 73% for non-phytate P (NPP) from plant ingredients and 80% for NPP from mineral and animal ingredients (P< 0.001). The increase in total digestible dietary P following the addition of microbial phytase (PhytM) fromAspergillus niger(P< 0.001) was curvilinear and about two times higher than the increase following the addition of plant phytase, which leads to a linear response (P< 0.001). The response of digestible P to PhytM also depends on the amount of substrate, PP (PhytM2× PP,P< 0.001). The digestibility of dietary P decreased with dietary Ca concentration (P< 0.01) independently of phytase but increased with body weight (BW,P< 0.05). Although total digestible dietary P increased linearly with total NPP concentration (P< 0.001), retained P (g/kg), average daily gain (ADG, g/day) and average daily feed intake (ADFI, g/day) increased curvilinearly (P< 0.001). Interestingly, whereas dietary Ca negatively affected P digestibility, the effect of dietary Ca on retained P, ADG and ADFI depended on total dietary NPP (NPP × Ca,P< 0.01,P< 0.05 andP< 0.01, respectively). Increasing dietary Ca reduced retained P, ADG and ADFI at low NPP levels, but at higher NPP concentrations it had no effect on ADG and ADFI despite a positive effect on retained P. Although the curvilinear effect of PhytM on digestible P increased with PP (P< 0.001), this effect was lessened by total NPP for ADG and ADFI (PhytM × NPP and PhytM2× NPP,P< 0.05) and depended on both total NPP and Ca for retained P (PhytM2× NPP × Ca,P< 0.01). This meta-analysis improves our understanding of P utilization, with major modulating factors taken into account. The information generated will be useful for the development of robust models to formulate environmentally friendly diets for growing pigs.
doi:10.1017/s1751731112000560 pmid:23031558 fatcat:7ksabmpa3jbk7j56y5qvjspn4e