High Level Cereal Diets for the Growing/Finishing Pig: VII. The Performance Of Weaned Pigs Grown To Cutter Weight (160 lb live weight) on Iso-Nitrogenous-Maize Based Diets Containing Different Levels of Lysine and Tryptophan

Abstract

SUMMARYIn a randomized block 3x2 factorial experiment 72 Large White type weaner pigs were individually and restrictedly fed, from 501b (22–7 kg) to approximately 1601b (72–7 kg) live weight, iso-nitrogenous (16% crude protein) maize-based diets (as wet mashes with 2:1 ratios of water to dry food) containing 0–15%, 0–22% or 0–29% tryptophan and either 0–85% or 0–97% lysine. Overall, for the period in its entirety and in the period from the start to 110 lb (50–0 kg) live weight, the diets containing 0–22% and 0–29% tryptophan gave a similar performance. Together they gave a significantly superior performance compared with that obtained from the diets containing 0–15 % tryptophan. Pigs fed the diets containing 0–85 % lysine converted their food better and grew faster than pigs fed the diets containing 0–97 % lysine. These differences were significant (P <0–05) for both parameters in the period from 110 lb (50–0 kg) live weight to the finish of the experiment at 1601b (72–5 kg) live weight and significant (P <0–05) for efficiency of food conversion in the overall experimental period.