Understanding hepatic lipidosis in dairy cattle — a periparturient metabolic disease with significant welfare implications.
Fatty liver causes significant welfare impairment through hepatic dysfunction and its consequences. The liver's ability to process ammonia, metabolise drugs, and support immune function is all compromised when fat infiltration is severe. Affected cows have reduced ability to fight infection — they are more susceptible to mastitis, metritis, and respiratory disease in the critical periparturient period.
The subclinical impact of fatty liver is often unrecognised. Mild-to-moderate hepatic lipidosis may not cause obvious clinical signs but significantly impairs metabolic function, reducing reproductive performance and milk production. Cows with fatty liver take longer to return to positive energy balance, have extended anoestrus, and experience poorer conception rates.
Prevention focuses on avoiding over-conditioning at drying off (target BCS 2.5-3.0 for Holstein) and minimising body condition loss in the close-up dry period. Transition cow management — maximising dry matter intake before calving, gradual dietary transitions, and monitoring ketosis — reduces the degree of negative energy balance that drives fatty liver development.