One factor that plays a role in the success of the transition period is the cow’s body composition, more specifically the fat and muscle of the cow. Both fat and muscle tissues are mobilized during the transition period to compensate for the negative nutrient balances and provide precursors for milk and milk components.

The dry period, usually lasting 60 days before calving, serves essential roles in preparing cows for lactation, promoting mammary cell renewal and facilitating treatment for subclinical mastitis. However, shortening or eliminating this period has become a strategy to manage milk production, redistributing energy balance and mitigating the risk of metabolic disorders like subclinical ketosis.

Why are fat supplements fed? Because in early lactation, cows cannot eat enough to meet their increasing milk production energy requirements. Thus, cows go into negative energy balance. This is an issue for especially the first one-third of a lactation. And, this negative energy balance is more pronounced and for a longer period of time for cows beyond their first lactation. Consequently, fat supplements are used to increase energy density of the ration. But, if a fat supplement decreases dry matter intake (DMI), the benefit of using it is decreased.