LYSINE REQUIREMENT OF PIGS WEIGHING 7 TO 19 KG LIVEWEIGHT

One hundred and forty-four crossbred pigs, weaned at 4 wk of age at an average initial weight of 7.0 kg were allotted to six dietary treatments. The diets were formulated to contain two protein levels (18 and 20%) and three lysine levels (1.0, 1.15 and 1.30%). There were no significant differences (P > 0.05) in the feed intake of pigs fed any of the six diets. Growth rate and feed efficiency of pigs were significantly improved by increasing the protein level in the diet from 18% to 20%. At both the 18% and 20% dietary protein levels there was a significant improvement in growth rate and feed efficiency as lysine level in the diet was increased from 1.0 to 1.15% but an increase from 1.15 to 1.30% tended to decrease these performance criteria. The data suggest that rapidly growing pigs fed barley-wheat-soybean-meal-based diets have a dietary requirement for 20% protein and approximately 1.15% lysine over the range 7–19 kg liveweight. Key words: Lysine, protein, requirement, starter pigs