Most of the metabolic problems of the dairy cow happen during the first two weeks of lactation. It has been reported that nearly 25% of the cows that leave herds do so during the first 60 days in milk (DIM). After calving, the requirements for energy increase due to colostrum production while dry-matter intake is reduced drastically. The mammary gland at four days post calving has increased demands for glucose (3 times), amino acids (2x) and fatty acids (3x) when compared to the uterus at 250 days of gestation. The mismatch between nutrient intake and demand generates a negative energy balance during several weeks after calving.
KETOSIS CHALLENGES
Canadian researchers (Tatone et al., 2017) published in the Journal of Dairy Science the results from an observational study of 3,042 Ontario herds to estimate risk factors for ketosis in dairy cows. Ketosis was diagnosed as milk β-hydroxybutyrate ≥ 0.15 millimoles per liter (mmol/L) at the first dairy herd improvement association test when tested within the first 30 days in milk. The overall prevalence of ketosis in Ontario herds was 21%. The authors reported the following risk factors associated with having ketosis:
> Seasonality: Summer (20.0%) and Autumn (18%) had lower prevalence than Winter (26%) and Spring (25%).
> Breed: Jerseys had more than 1.46 times higher odds of succumbing to ketosis than Holsteins.
> Number of lactations: Increased days dry and longer calving intervals, for multiparous animals, and older age at first calving for primiparous animals increased the odds of ketosis at first test.
> Milk fat yield: ≥ 2.7 lb. per day at the last test of the previous lactation was associated with decreased odds of ketosis in the current lactation (odds ratio: 0.56).
Continue reading this article published in Dairy Herd Management.
