RESUMEN
Supplementation of a combination of lysolecithin, a synthetic emulsifier, and monoglycerides (LEX) in liquid and dry form to broiler diets with different energy levels was investigated to determine their effect on performance, litter quality and subsequent occurrence of footpad lesions. One thousand two hundred and forty-eight-day-old Ross 308 broilers were assigned to 1 of 6 treatments for a 42-day study: a basal diet with a normal energy content (NE); NE + 300 g/t LEX in liquid form (LEL); NE + 500 g/t LEX in dry form (LED); a basal diet with low energy (LE, -90 kcal/kg starter, -100 kcal/kg grower, finisher), LE + 300 g/t LEL and a LE + 500 g/t LED. Each treatment consisted of 13 pens of 16 birds each. Diets were fed in 3 phases (starter d 0-10, grower d 11-21, finisher d 22-42). Feed intake and weight were measured on d 0, 10, 21, and 42. On d 42 a litter sample was collected from each pen and 2 birds per pen were assessed for footpad lesions and breast scald. Data were analyzed using JMP 16, with means separation achieved using Tukey's HSD; significance was assumed at P < 0.05. Results showed a higher (P < 0.05) cumulative bodyweight gain with LEX supplementation (NE CON = 2,718 g, NE+LED = 2,829, NE+LEL = 2,895, LE CON = 2,722, LE+LED = 2,787, LE+LEL = 2,893; P = 0.0027). An increased feed intake was observed for the LE diets, however cumulative FCR of LE+LED and LE+LEL remained equal to the NE control (1.657 NE CON, 1.657 LE+LED, 1.623 LE+LEL; P > 0.05), suggesting LEX enabled the birds to compensate for the energy gap. Litter dry matter was significantly improved with both LED and LEL supplementation compared to the control groups, and resulted in lower (P < 0.05) occurrence and severity of footpad lesions and breast scalds. Considering the income over feed cost (IOFC) of the NE treatment as the reference point for comparison, all other treatments improved profitability, with NE+LEL and LE+LEL achieving the greatest IOFC with 154.58 and 175.96 /1,000 birds respectively. In conclusion, feeding broilers a combination of lysophospholipids, a synthetic emulsifier and monoglycerides resulted in improved bird performance. The use of the LEX also improved litter quality and footpad health, therefore improving animal welfare indicators such as breast scald and footpad measurements.
