Energy Metabolism in Growing Boars

Energy utilization and requirement of broiler breeders during the production phase

“…However, caution must be taken when considering this linearity, as it may not be applicable in all conditions and is not constant along the birds' age because it constantly changes mainly due to egg production. Although this suggests that a regression between ME and RE used to estimate maintenance requirements and energy utilization efficiencies, the approach classically carried to estimating ME for maintenance has several assumptions, such as constant requirement and efficiency independent of feeding level, that have been challenged by Kielanowski (1965) and Romero et al (2009) . Previous studies on broiler breeders ( Johnson and Farrell, 1983 ; Rabello et al, 2004 ; Sakomura, 2004 ) have shown that energy intake level and temporal variations in energy utilization can affect the efficiency of ME utilization.…”

Efficiency of metabolizable energy utilization for maintenance and growth by the weanling pig

“…Ludvigsen (1980) demonstrated that the heat production and efficiency of energy utilization of barrows fed diethylstilbestrol + methyltestosterone was comparable to boars and gilts. -Janiak et al (1980) reported that the energy costs for maintenance and protein deposition were higher for boars than castrated males. Over the weight range of 30 to 100 kg, Walach-Janiak et al…”