46 DAIRY FARMING
BALANCING WINTER RATION SUPPLEMENTATION FOR OPTIMAL COW PERFORMANCE
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s producers begin to open maize and grass silage clamps, paying close detail to forage quality is essential to ensure the nutritional requirements of dairy herds are met, says Dr Richard Kirkland, ruminant nutritionist for Volac Wilmar Feed Ingredients. “Balancing a winter ration should begin with silage analysis to fully understand the quality of the basal forage to enable appropriate supplementation with key macronutrients including fibre, starch, sugar, protein and fat,” he says. “The
primary target – ensuring energy supply is maximised.” Delivering adequate energy to support milk production will always be a challenge with modern high-yielding cows and that energy will necessarily come from a range of sources. “High D-value silages targeted to the highest-yielders will improve energy availability, but when it comes to supplementation we must look for a range of energy sources to give the ration the balance needed,” says Dr Kirkland. Starchy cereals provide a boost over digestible fibre
sources of energy but limits will soon become clear as overreliance on either of these types of raw material will lead to problems or productivity shortfalls. With wheat and barley, rapid rates of starch fermentation in the rumen generates acid which drives down rumen pH, and with that an increased risk of acidosis. This effect will be acutely evident in the milk cheque with a fall in milk fat percentage, but the knock-on effects of poor rumen function will reduce fibre digestibility – reducing energy delivered from the basal
An essential and unique energy source, dairy cows require 15-20% of energy supply from fat, which could be heading toward 6% in the ration dry matter to meet requirements as a key nutrient the cow needs to make milk optimally, says Dr Richard Kirkland, Global Technical Manager for Volac Wilmar Feed Ingredients.
LIVESTOCK & POULTRY ME
OCTOBER-DECEMBER 2021
