Efectos de la suplementación de levadura viva (Saccharomyces cerevisiae) y dietas con diferentes densidades de nutrientes en cerdos en crecimiento-finalización bajo estrés calórico severo

Growth performance and health status in three successive feeding phases (FI, FII and FIII, corresponding to 22-60, 60-90 and 90-113 kg of body weight, respectively), carcass characteristics and feed cost per kg gain by effects of different nutrient densities and of supplementation with live yeast, were evaluated in 60 growing-finishing pigs housed under severe heat stress conditions. Three experimental dietary treatments were compared: a positive control (TP) diet formulated to satisfy the total nutritional requirements in summer; a negative control (TN) formulated to have a reduced nutrient density; and a yeast control (SC) diet that consisted of TN supplemented with yeast (0,7 kg/ton). In FI, pigs fed the SC diet had a better feed conversion ratio (CA) than those under the TP diet (P < 0,05). In FIII, SC resulted in a higher average daily feed intake (CDA), average daily gain (GDP) and average of body weight (P < 0,05) compared to TN. In FI, pigs fed TN showed the greatest incidence of mild diarrhea, followed by the TP (P < 0,05). In FII, pigs fed the TN showed the highest incidence of slight respiratory disease (cough), compared to TP and SC (P < 0,05). Carcass characteristics were not modified (P>0,05). The feed cost per kg of weight gain was decreased with the SC compared to TP (P < 0,05). In conclusion, supplementation with live yeast during high heat stress improved growth and health and reduced feed cost per kilogram gain.