Discipline: Veterinary Medicine
A study was conducted to determine the efficacy of supplementing Llysine sulfate on the growth performance, nitrogen balance and carcass characteristics of swine. Eighteen pigs (initial BW: 11.8±0.51 kg, Landrace x Large White x Duroc) were randomly allotted to two dietary treatments using a completely randomized design. Dietary treatments were corn-soybean mealbased diets supplemented with either L-lysine monohydrochloride (Treatment 1) or L-lysine sulfate (Treatment 2). Experimental diets were formulated to be fed in a 4-phase diet series. The supplemental lysine sources were added to provide 0.195, 0.165, 0.250 and 0.189% of total lysine in the pre-starter, starter, grower, and finisher diets, respectively. Four barrows (~60 days of age) from each treatment were used in a nitrogen balance trial. Six representative animals (~150 days of age) per treatment were slaughtered and evaluated for carcass characteristics. Replacing L-lysine monohydrochloride with L-lysine sulfate in pre-starter to finisher diets did not affect growth performance, nitrogen balance and carcass characteristics. Economic analysis showed that feed cost efficiency may be improved using L-lysine sulfate. Based on the prices of feed ingredients during the study, a PhP 0.81 saving per kilogram gain in weight was attained when L-lysine sulfate was used which could be attributed to its lower price per kilogram. L-Lysine sulfate may be effectively used as an alternative to L-lysine monohydrochloride as a supplemental lysine source in swine diets.