Dietary digestible lysine levels in diets for barrows from 60 to 100 days of age

In order to evaluate digestible lysine levels on the performance and carcass traits of castrated male pigs from 60 to 100 days of age, 300 barrows with initial weight of 25.0+/-0.52 kg were allotted in a completely randomized block design with five treatments (0.65, 0.75, 0.85, 0.95, and 1.05% digestible lysine levels), five replicates, and 12 pigs per experimental unit. There was no effect of digestible lysine levels on average daily feed intake. The average daily gain increased and feed conversion improved quadratically with increasing dietary digestible lysine levels. There was no effect of the digestible lysine levels on pig backfat thickness; however the carcass yield and quantity of meat increased quadratically with increasing digestible lysine levels in the diets. The levels of 0.96 and 0.92% digestible lysine, corresponding to the estimated intakes of 18.69 and 17.69 g/day provide the best results of weight gain and feed conversion, while levels of 0.89 and 0.90%, corresponding to the estimated intakes of 17.28 and 17.52 g/day, provide the best results of yield and quantity of meat in the carcass of barrows from 60 to 100 days of age.