D-3-Hydroxybutyric acid concentration as indicator of the nutritional status of two genetically different types of Merino sheep subjected to different nutritional levels

Ewes of South African Mutton Merino (a meat breed) and Merino (a wool breed) were used in a 15-week indoor study to quantify the influence of nutrient intake on D-3-Hydroxybutyric acid (OHB) concentrations when fed at different levels of their respective nutrient requirements during pregnancy and lactation. OHB levels of 0.210; 0.339; 0.412; 0.522 mmol/l and 0.135; 0.250; 0.265; 0.364 mmol/l for SA Mutton Merino and Merino ewes during week 17 and 20 of pregnancy and week 2 and 5 of lactation were predicted for adequate energy intake levels. It was concluded that the concentrations of OHB were in most cases negatively correlated with energy intake, although correlation coefficients were generally low during certain periods.