Resumen

CORREA-CALDERON, Abelardo et al. Efecto de un sistema de enfriamiento a espacio abierto en la eficiencia productiva de novillos holstein durante el verano. INCI [online]. 2004, vol.29, n.2, pp.86-88. ISSN 0378-1844.

To evaluate the effects of an open space cooling system on weight gain, feed intake and respiration rate, 32 Holstein steers (373kg) were randomly assigned in two treatments, a control group with shade only in the pen (n=16) and a second group with an open space cooling system (n=16). The open space cooling system consisted of a 2.4m diameter blade fan circulating 1416m³/min of air, with oscillation coverage of 90º. The amount of water discharged was 12l/min. The study was conducted for 90 days with a daily maximal temperature-humidity index (THI) of 84 to 90. There was no difference (P>0.05) in daily weight gain (1.34 ±0.05 vs 1.41 ±0.05kg/day) or feed intake (9.9 vs 10.5kg/day) for control and cooling groups, respectively. However, there was a tendency to increase the productive performance and to reduce the respiration rate (P<0.05) in steers under the cooling system as compared to control group (89 vs 104 breaths per minute), indicating an improvement in their comfort.

Palabras clave : Estrés Calórico; Ganado de Carne; Sistema de Enfriamiento.