Early Weaning Possibly Increases the Activity of Lipogenic and Adipogenic Pathways in Intramuscular Adipose Tissue of Nellore Calves

Abstract

This study aimed to evaluate by wide-expression profile analysis how early weaning at 120 days can alter the skeletal muscle metabolism of calves supplemented with a concentrated diet until the growth phase. Longissimus thoracis muscle samples were obtained by biopsy from two groups of calves, early weaned (EW; n = 8) and conventionally weaned (CW; n = 8) at two different times (120 days of age—T1 [EW] and 205 days of age—T2 [CW]). Next, differential gene expression analysis and functional enrichment of metabolic pathways and biological processes were performed. The results showed respectively 658 and 165 differentially expressed genes when T1 and T2 were contrasted in the early weaning group and when early and conventionally weaned groups were compared at T2. The FABP4, SCD1, FASN, LDLR, ADIPOQ, ACACA, PPARD, and ACOX3 genes were prospected in both comparisons described above. Given the key role of these differentially expressed genes in lipid and fatty acid metabolism, the results demonstrate the effect of diet on the modulation of energy metabolism, particularly favoring postnatal adipogenesis and lipogenesis, as well as a consequent trend in obtaining better quality cuts, as long as an environment for the maintenance of these alterations until adulthood is provided.

Effects of Early Weaning on Performance and Carcass Quality of Nellore Young Bulls

“…Although early weaning is an interesting strategy to enhance the reproductive performance of cows, this practice can entail significant disadvantages for calves, mainly when adequate nutritional conditions are not provided after this period [ 25 ]. Studies on early weaning in beef calves have revealed that the implementation of post-weaning supplementation strategies can equalize the performance of traditionally weaned calves, especially when the latter do not receive supplementation [ 16 , 21 , 27 ]. In the present study, the results indicate that calves in the EW group exhibited reduced body weight compared with those in the CW group from 240 days of age and continuing throughout the experiment.…”

“…Although this practice is not aimed at surpassing the performance of traditionally weaned calves, the combination of early weaning with supplementation strategies can result in significant improvements in post-weaning growth, as well as positively impacting carcass and meat quality [ 14 , 15 ]. According to a recent study by Pedro, et al [ 16 ], adopting weaning at 120 days of age in Nellore calves and a supplementation regimen demonstrated similar growth compared to those weaned at 205 days without supplementation. Moreover, in this study, early weaning associated with a supplementation regimen positively affected genes with the potential to increase intramuscular fat deposition in meat.…”