Produção Nacional
Revisado por pares
Metabolic Profile of Steers Subjected to Normal Feeding, Fasting, and Re-Feeding Conditions
2020; Multidisciplinary Digital Publishing Institute; Volume: 7; Issue: 3 Linguagem: Inglês
10.3390/vetsci7030095
ISSN2306-7381
AutoresEnrico Lippi Ortolani, Celson Maruta, Raimundo Barrêto Júnior, Clara Satsuki Mori, Alexandre Coutinho Antonelli, Maria Cláudia Araripe Sucupira, Antônio Humberto Hamad Minervino,
Tópico(s)Genetic and phenotypic traits in livestock
ResumoThe effects of feeding, fasting, and re-feeding on the metabolic and ruminal profiles of growing cattle were studied. Blood and urine samples were obtained from 12 crossbred steers weighing approximately 300 kg during the following periods: 11 h of normal feeding (postprandial period), 48 consecutive hours of fasting, followed by 48 h of re-feeding. Compared with the postprandial period, fasting caused the following modifications: moderate hypoglycemia accompanied by remarkable lipolysis detected by the increase in plasma levels of free fatty acids (FFAs); absence of hepatic lipidosis, as there were no changes in aspartate aminotransferase activity or serum cholesterol levels; mild ketogenesis, confirmed by the slight increase of β-hydroxybutyrate (βHB); increased amino acid burn for energy production, verified by the increase in serum urea contents. There were strong positive correlations between the plasma levels of FFAs and βHB (r = 0.68; p < 0.001), fasting duration and FFA concentration (r = 0.92; p < 0.00001), and fasting duration and serum urea (r = 0.52; p < 0.001); there was a negative correlation between fasting duration and blood glucose (r = -0.52; p < 0.0001). During this same period, mild hypovolemia characterized by an increase in intravascular volume deficit was observed. The metabolic condition observed during fasting was completely reversed during re-feeding, except for the temporarily higher proteolysis.
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