Glucose and NEFA concentrations are subject to considerable
variation in cows and are influenced by stress (Grandin, 1997;
Uetake et al., 2006) and potentially by feed intake and diurnal
rhythms (Sutton et al., 1988; Bitman et al., 1990). A negative correlation has been reported between walking activity and NEFA
concentrations in lactating dairy cows (Adewuyi et al., 2006). In
non-lactating cows, Brickner et al. (2007) demonstrated that different blood-sampling protocols may influence NEFA concentrations
through creating different levels of handling stress.