Fertility in jeopardy if fats cut from diets

Farmers tempted to cut out rumen-protected fats from dairy cows’ diets, following recent hikes in prices, could be putting cow fertility in jeopardy.

Rumen-protected fats are a vital source of energy and after calving, in particular, cows need this boost to avoid an energy gap, which could affect health and fertility, says nutritionist Melanie White.

She says despite some rumen-protected fats approaching £800/t due a shortage of palm oil and oil prices, in many cases it is still cost effective to include them. “The concern is, if the milk price doesn’t increase to help equal out rising input costs, then people may cut out rumen-protected fats and this would be a wrong decision due to the knock-on effects it could have on fertility and production.”

And although fats can come from other sources such as cereals, they don’t have the same energy concentration as some rumen-protected fats, says Volac’s Richard Kirkland.

“Our rumen-protected fat product contains more than 2.5 times the metabolisable energy concentration of typical cereals and the energy is used far more efficiently for milk production.”

This is especially important during early lactation, when a cow’s appetite and dry matter intake is at its lowest, making the energy density of the diet important to avoid cows milking off their back.

“Cows losing body condition will not only take longer to start cycling but studies at Nottingham University indicate a reduction in conception of 5% with every 0.5 unit drop in body condition during early lactation.”

Research also shows that feeding high-fat rations gives better-quality oocyte development, follicle size and progesterone production, which are all factors influencing fertility, he adds.

Fat also has health benefits and avoids the risk of acidosis, which can be a problem when increasing cereals in the diet as a source of energy. Other health benefits include reducing the incidence of metabolic disease such as fatty liver and ketosis.

And farmers will certainly get an economic response from continuing to feed rumen-protected fats, even at current prices. “For example, feeding 450g a day of our rumen-protected fat at £800/t, with a milk price of 25ppl can produce a profit of 21.5p a cow a day because of the extra milk produced. And that doesn’t take in to account the long-term health and fertility benefits,” adds Dr Kirkland.

See more