Thermoregulatory differences in lactating dairy cattle classed as efficient or inefficient based on residual feed intake

Abstract

It is suggested that one-third of the inter-animal differences in efficiency is explained by differences in digestion, heat production, body composition and activity; while the remaining variation is the result of energy expenditure due to biological processes such as ion pumps and mitochondrial function. Inefficient animals may be wasting energy on inefficient processes resulting in increased heat production that may be reflected by differences in skin and core temperature. While the association between heat production and residual feed intake (RFI) has been touched on, it is yet to be fully elucidated. It is hypothesised that more efficient animals will expend less energy as heat, which wi..