Digestible lysine levels for barrows housed in ambient of heat stress from 95 to 115 kg of weight

Abstract

With the objective of evaluated different digestible lysine levels 35 castrated male pigs with initial weight of 95.6 ± 1.1kg and housed in bioclimatic rooms regulated at 32ºC were distributed in experimental design of randomized blocks into of five digestible lysine levels (0.66; 0.78; 0.90; 1.02 and 1.14%), seven replications and one pig per experimental unit. The supply of feed was realized twice per day and restricted by lesser feed intake within each repetition. The final body weight, average daily feed intake, backfat thickness, muscle depth rate, longissimus dorsi muscle area and carcass meat percentage were not affected by digestible lysine levels. There was quadratic trend on average weight gain (P=0.08) and this way, the feed conversion showed a quadratic effect (P=0.05), which estimated digestible lysine levels of 0.98 and 0.99%, corresponding at estimated intake of 23.04 and 26.21g/day of digestible lysine, respectively. The digestible lysine levels also showed quadratic effect on the weight and yield of carcass, which were estimated in 0.95 and 0.86% of digestible lysine, respectively. There was linear decrease in small intestine relative weight. The digestible lysine level for finishing phase barrows and housed under heat stress is 0.98%.