Determination of metabolizable energy (ME) and standardized ileal digestible lysine (SID Lys) requirements for finishing pigs with high intramuscular fat
The study was conducted on 675 three-way crossbred finishing pigs (Duroc boars × LY, YL crossbred sows). It was to determine optimal dietary levels of metabolizable energy (ME) and standardized ileal digestible lysine (SID Lys) for these high-intramuscular fat (>3.2%) commercial pig lines, in order to improve growth performance and meat qualities. The experiment followed a two-factor completely randomized design with three levels of ME (3,200, 3,300, and 3,400 kcal/kg) and three levels of SID Lys (0.6, 0.7, and 0.8%), resulting in nine treatments (3 × 3). Each treatment included 25 pigs per pen, with each pen considered one replicate, and three replicates per treatment (3 pens/treatment × 9 treatments), totaling 675 pigs with an average initial body weight of 80 kg. During the growing phase (20 - 80 kg), pigs across all treatments were fed the same diet. Experimental diets were applied during the finishing phase from 80 to 110 kg body weight. Crude protein levels were maintained constant across all diets. The ratios of SID methionine + cystine, threonine, and tryptophan relative to SID Lys were fixed at 58%, 65%, and 18%, respectively, all treatments. The results indicated that the diets varying metabolizable energy and standardized ileal digestible lysine levels did not affect the feed intake of finishing pigs. Using diets for during the finishing pigs’ stage had the following nutritional: ME 3,300 kcal/kg, CP 14%, calcium 0.9%, total phosphorus 0.54%, and SID levels of Lysine, Methionine + Cystine, Tryptophan, and Threonine at 0.7%, 0.50%, 0.14%, and 0.53%, respectively, to obtain the best growth performance and meat quality.
