By Dr Richard Kirkland,
Global Technical Manager, Volac Wilmar Feed Ingredients
TO determine the effects of offering fat supplements to freshly calved cows, when body fat is also being mobilised to provide energy, researchers at Michigan State University evaluated the response to Mega-Max, a rumen-protected fat supplement containing a 60:30 ratio of C16:0 (palmitic) to C18:1 (oleic), on cow performance through early lactation.
C16:0 is very beneficial in improving milk fat production and yield, but this may be at the expense of body condition and weight loss in early lactation, the knock-on effects of which may include poor fertility.
In contrast, delivering C18:1 to the small intestine, achieved by supplementing with rumen-protected calcium salts, improves total fat digestibility and can enhance fertility through improved egg and embryo development. Unlike C16:0, C18:1 helps partition nutrients toward body fat stores, reducing body condition loss in the critical early lactation period.
During the study, control and fat-supplemented cows maintained similar body condition throughout the fresh period (days 1-24 in milk). However, the fat-supplemented group saw notable increases in milk fat percentage and yield, resulting in 3.1kg more energy-corrected milk than the control group.
Supplementing cows in the fresh period and then throughout the peak period (days 25-67 in milk), did not affect dry matter intake but increased milk yield by 5.1kg per day and milk fat content by 0.2 per cent. This led to a significant increase in milk fat yield from 1.76kg to 2.07kg per day in control and fat-supplemented treatments, respectively. Crucially, this was achieved without increased loss of body weight or condition score.
When considering fat supplements for dairy cows, lower C16:0, with higher C18:1, supplements are most appropriate through early lactation to help partition nutrients toward body reserves and prevent excessive body condition loss. Furthermore, providing more C18:1 to the ovary is beneficial for the development of embryos and the improved digestibility provides an additional boost in megajoules of energy.
Moving into mid-lactation, target body condition score should be met so a higher C16:0 supplement (80 per cent to 90 per cent C16.0) can be considered to fuel milk and milk fat production.
Results from the latest study, coordinated by Prof Adam Lock, Michigan State University, were presented at the American Dairy Science Association conference and discussed during the recent Webinar organised by Volac Wilmar. This was in conjunction with Dr Jonas de Souza, ex Michigan State University, and Prof John Newbold from Scotland’s Rural College (SRUC).
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