An existing energy partition model that relates protein and lipid retention in growing pigs (60 kg) to dietary energy intake was extended to include environmental temperature. The extended model for 45- to 75-kg pigs can be used to predict animal heat production at each feeding level, lower limit of the zone of thermoneutrality at each feeding level and incremental energy conversion efficiency over a range of feeding levels and environmental temperatures. The model predictions were validated in two ways. (1) Incremental energy conversion efficiencies over a range of feeding levels and environmental temperatures, as determined in three studies cited in the literature, were compared against the energy conversion efficiencies predicted by the model. (2) The rates of protein deposition and liveweight gains in growing pigs housed at 21 °C and 6 °C, were compared against the model predictions. While the model should receive further testing, both the above tests confirmed that low temperature can be related to feeding level and rates of tissue gain in pigs in a predictable manner. Key words: Pig, temperature, model, energy retention
Type I reaction center from the green sulfur bacterium Chlorobium tepidum: is Chl a a primary electron acceptor?