Reduced AgRP activation in the hypothalamus of cows with high extent of fat mobilization after parturition

Endogenous and dietary lipids influencing feed intake and energy metabolism of periparturient dairy cows

“…Whole body fat oxidation [47,63] was 500% to 700% in fat compared with lean cows, and the abundance of enzymes participating in hepatic peroxisomal and endoplasmic fatty acid oxidation as well as oxidative phosphorylation was 1.2-to 1.8-fold greater in fat cows compared with lean, pre-and postparturition [48]. Also, feed intake of fat cows compared with lean is generally lower already before parturition where plasma NEFA concentrations are not yet elevated [7,54,55].…”

“…Based on these findings, it was assumed that hypoleptinemia during early lactation may activate NPY orexigenic pathways and attenuate anorexigenic CART pathways to promote hyperphagia in sheep [53]. However, Börner et al [63] found that the percentage of cFOS-activated AgRP neurons was lower in cows with a high fat mobilization relative to cows with a lower fat mobilization in early lactation and that this effect was not because of a different level of feed intake. Rather, the number of cFOS-activated AgRP neurons correlated negatively with oxygen consumption and plasma NEFA concentrations and positively with the respiratory quotient of dairy cows.…”

“…Rather, the number of cFOS-activated AgRP neurons correlated negatively with oxygen consumption and plasma NEFA concentrations and positively with the respiratory quotient of dairy cows. The authors concluded that AgRP activation plays a pivotal role in the regulation of substrate utilization and metabolic rate but less in the level of feed intake consumed during early lactation [63].…”

Indices of heart rate variability as potential early markers of metabolic stress and compromised regulatory capacity in dried-off high-yielding dairy cows

“…In this context it is interesting to note that L MAX grouping of cows (n = 16) and re-analysis of data obtained under normal housing conditions (Schäff et al, 2012, Börner et al, 2013) also reveal differences between <L MAX and >L MAX groups. Compared with cows of the >L MAX group, cows of the <L MAX group had lower blood insulin levels during weeks −5 to −2 ap and showed constantly lower DMI and ECM during weeks 2 to 5 of lactation.…”

“…To further test the possibility that L MAX could predict different phenotypes we used data obtained from other subprojects of the joint research project (Schäff et al, 2012, Börner et al, 2013 during weeks − 5 to −2 (ap) and weeks 2 to 5 (pp). Results of these data re-analysis (n = 16 cows) are given in Table 6 that summarizes parameters differing significantly between > L MAX and < L MAX cows.…”