Comorbid development of fatty liver and hyperketonemia and its impacts on performance in periparturient dairy cows
Date
2025-01-16Author
Praisler, Grace
Department
Animal Sciences
Advisor(s)
White, Heather
Metadata
Show full item recordAbstract
The transition from late gestation to early lactation in dairy cattle has been characterized as a pivotal point involving many physiological changes and adaptive responses that will determine a cow’s success in the production of her subsequent lactation. At the onset of lactation, there is an increase in energy demand to support lactation that is commonly not supported by sufficient dietary nutrients, as a natural decrease in dry matter intake (DMI) is observed around parturition. This creates an imbalance as the energy demands surpass the energy and nutrients supplied by the diet, resulting in a negative energy balance (NEB). Some key adaptations occurring during this time include alternative metabolism pathways, changes in endocrine status, and immune fluctuations.
More commonly than not, cows will inadequately adapt to an NEB and other challenges faced during the transition to lactation period, causing them to rely more heavily on mobilizing body reserves, especially fatty acids (FA) from adipose tissue. In this case, increased FA mobilization increases the risk of exceeding hepatic capacity for the complete oxidation of FA and subsequently developing lipid-related metabolic disorders, such as fatty liver (FL) and hyperketonemia (HYK). These metabolic disorders independently have negative impacts on the production, overall health, and profitability of dairy cows, with a high incidence of HYK (40 to 60%) and FL (above 50%) in dairy cows in the United States. The nature of these two lipid-related metabolic conditions is physiologically and biochemically related to the NEB challenge during the transition period and usually develop concurrently; however, there is a gap in research knowledge on how comorbid development influences cow performance and success. Therefore, the hypothesis of this thesis was there would be detrimental differences in performance, metabolic status, liver function, and inflammatory status in cows that naturally developed FL with the presence of HYK, when compared to cows that developed FL alone and cows that did not develop either.
In this experiment, the objective was to retrospectively characterize cows into three groups (GRP): 1) NonFL, NonHYK, 2) FL, NonHYK, 3) FL, HYK and to determine the impacts of comorbid development of FL and HYK in multiparous Holstein cows on production and health parameters throughout the transition period. Liver samples were collected via liver biopsy and liver triglycerides (TG) concentrations were quantified by Folch extraction and expressed on a DM basis to diagnose, using previously defined thresholds, if a cow developed FL if their liver TG content was ≥ 13.9% DM or NonFL if their liver TG content was < 13.9% DM. Cows were also diagnosed with HYK by quantifying if a cow had a plasma beta-hydroxybutyrate (BHB) concentrations ≥ 1.2 mM or NonHYK if their plasma BHB was < 1.2 mM during the first 14 days postpartum. In this study, no differences were detected in milk yield and components between the groups. All cows had similar prepartum baseline liver TG concentrations, while cows under comorbid conditions (FL, HYK) had the greatest accumulation of liver TG during the postpartum period, with peak liver TG content occurring at +14 days relative to calving (DRTC) and experienced inadequate recovery to baseline levels by +56 DRTC, compared to cows without HYK (NonFL, NonHYK and FL, NonHYK). Cows with FL (FL, NonHYK and FL, HYK) tended to have greater concentrations of circulating FA pre- and postpartum and decreased postpartum insulin and glucose concentrations. Additionally, cows with FL, HYK tended to have decreased postpartum DMI and lost more body weight and body condition throughout the transition period. Finally, the FL, HYK group experienced an increase in aspartate aminotransferase: alanine aminotransferase and more fluctuations in inflammatory status, such as a tendency of decreased prepartum serum amyloid A and tended to have increased postpartum lipopolysaccharide-binding protein concentrations.
We concluded that comorbid development of FL and HYK does negatively impact a cow’s metabolic, energy, and inflammatory status throughout the transition period but did not impact production metrics in this study. Although this thesis provides novel insight into the comorbid development of FL and HYK in dairy cattle, we were not able to fully compare the independent development of HYK independent of FL due to a lack of the NonFL, HYK group. Future research is needed to fully understand the etiology and risk factors of these lipid-related metabolic disorders and to possibly be able to predict before the onset occurs and evaluate the economic losses of comorbidity.
Subject
Animal Sciences
Permanent Link
http://digital.library.wisc.edu/1793/90775Type
Thesis