Phosphorus intake and leg weakness in growing pigs

The 15 Large White pigs of the control group which were fed according to the Swiss recommendations received a piglet diet containing 0.32 g of digestible phosphorus (DP) per MJ digestible energy (DE) until 25 kg body weight (BW) and a grower diet containing 0.26 g DP per MJ DE until they were slaughtered at 45 kg BW. The diets of the three experimental groups, each comprising 15 piglets, contained either 20% less (P-) or 20 % (P+) and 40 % (P++) more DP than the diets P of the control group. The ratio of Ca to DP was 2.8 to 1 in all diets. The pigs P++ had a lower daily weight gain than pigs P and P- (620 g vs. 665 and 680 g, P < 0.001). Osteochondrosis scores were unaffected by DP intake. There was no treatment effect on metacarpal bone ash and phosphorus concentration, but the calcium concentration and the strength of the metacarpal bone was lower (P < 0.05) in animals fed diet P- compared to animals fed diet P+. In conclusion, the mineral level of the starter and grower diet P that corresponds to the Swiss feeding recommendations for pigs allows for the development of sound bones in growing pigs.