A CAREFUL balance will be needed with dairy cows' winter rations to make the most of home-grown forage, an ration expert warned this week.

Changing starch degradability of maize in clamps will be increasing now and producers are being told to watch out for the effect this will have on rumen pH.

“With a turbulent outlook for milk prices, it’s essential not to underestimate the importance of re-balancing rations to maintain milk quality and diet cost-effectiveness as the season progresses,” said Bronwen Pihlwret, QLF's nutritional adviser. “As farmers begin to move through maize clamps, they’ll notice that the starch degradability of the forage will improve.

“Therefore, it’s likely farmers will need to re-balance their rations to counteract this increase in degradability, to maximise rumen function by ensuring rumen protein and energy requirements are being met and rumen pH isn’t being disrupted,” she added.

“The starch element of maize breaks down into propionic acid in the rumen and this can lead to increased acidity which can depress rumen pH, so care must be taken to avoid sub clinical acidosis, particularly when fed with other cereals,” she explained.

To prevent the rumen environment becoming unstable, she advised feeding molasses in the ration, to not only buffer the rumen against the possible pH drop, but also to provide a vital source of energy for rumen microbes.

“Feeding molasses alongside maize with this year’s generally high protein grass silages, will provide the microbes with a source of rumen fermentable energy, to maximise forage breakdown and microbial protein production. This produces the amino acids essential for milk production, “she explains.

“Feeding a molasses, such as QLF’s TMR 50, at 1.5kg per head, achieving overall dietary sugars of 5 to 7% dry matter is a cost-effective way of supplementing protein to a diet, and to facilitate an optimal rumen environment,” said Ms Pihlwret.