Impacto da suplementação proteica materna durante o terço médio ou terço final da gestação sobre o metabolismo energético do tecido muscular de bezerros de corte

Abstract

ABSTRACT: This study evaluated the effect of maternal protein supplementation during mid or late gestation on energy metabolism of the skeletal muscle of beef calves. Sixteen pregnant cows were divided into 3 groups: CTRL (not supplemented); MID (supplemented from 30 to 180 days of gestation); and LATE (supplemented from 181 to 281 days of gestation). The supplement contained 30% crude protein. Thirty days after birth, blood and muscle samples of the calves were collected for analyses of gene expression, proteins, and metabolites. No differences (P ≥ 0.15) in birth weight, performance at weaning, or muscle expression of the genes evaluated (P ≥ 0.21) were observed. Calves born to CTRL cows had a lower ratio (P = 0.03) of p-AMPK/AMPK protein in the skeletal muscle. Calves born to MID cows had lower (P = 0.04) glucose concentration than those born to LATE cows. Changes in p-AMPK/AMPK protein, indicated a possible metabolic inflexibility in the skeletal muscle of calves born to CTRL cows. These results indicated that lack of protein supplementation in pregnant cows alter the energy metabolism of their calves and reflect in a metabolic inflexibility.