Feeding rumen protected fats to high yielding dairy cows offers multiple production benefits and can deliver a 40% return on investment, farmers heard at a recent Volac Wilmar industry event.
“The biggest benefits occur in early lactation” claimed ruminant nutritionist Dr Richard Kirkland.
He pointed out that milk yield will increase rapidly towards peak levels around 10 weeks post-calving, but while dry matter intakes also increase during this period, it is at a much slower rate.
This creates an energy gap in the animal’s diet which the cow fills by mobilising her own body fat. As cows lose body condition, animals are slower to resume cycling activity and get back in-calf.
“For every 0.5 unit drop in body condition, conception rates are typically reduced by 10%. This increases the number of days open, i.e. the number of days cows are not in-calf and costs anywhere from £2.50 to £5/day,” said Kirkland.
He outlined the results of research trials which show that feeding rumen protected fats reduces the number of days open in high yielding herds by 10 to 19 days.
Fats used in cattle rations contain twice the energy of cereals such as wheat. While there are various options available, Kirkland stressed the importance of using protected fat sources in cow diets.
“Fats increase the oil levels in the diet. When used incorrectly, they will suppress cow intakes. More importantly, they can interfere with digestion of rumen fibre, lower the availability of trace minerals and suppress butterfat in milk,” he said.
In contrast, feeding 0.5kg of a safe protected fat supplement increased energy density by 0.5 MJ of ME/kg DM without posing any risk of acidosis.