Influence of environmental temperature on growth performance in pigs

Abstract

The aim of the present paper is to present the effects of environmental temperature on energy balance, growth performance and nutritional requirements of growing-finishing swine and to assess the optimal temperature. The critical temperature is estimated at to about 20°C for growing pigs and to 15°C for finishing ones. The critical temperature corresponds to a maximal utilization of feed energy and its significance is discussed in terms of animal performance. Environmental temperature mainly affects fat deposition. In ad-libitum conditions, volontary feed intake decreases by 22 g/d/°C between 10 and 20°C, whithout any effect on daily weight gain. Between 20 and 30°C, this decrease is more pronounced (73 g/j/°C) and involves a reduction in daily weight gain (40 g/°C) and in body fatness. On the basis of reduced production costs and body fatness, the optimal temperature for growing-finishing swine reared on concrete slatted floors is assessed at 24-25°C. Studies on the interactions between temperature and nutritional requirements suggest that, in warm conditions, performance is improved in pigs fed high energy diets whereas, in the cold, growth is independent of feed energy concentration. The increase in energy requirement between 20 and 12°C is assessed at 25 kJ EM/kg^0.75/d/°C. The daily amount of essential amino acids required for a given weight gain or muscle gain does not vary with environmental temperature.