Match starch feeds to forage carefully to avoid acidosis in dairy cows

Failing to correctly match supplementary starch feeds to the low dry matter, acidic silages in many winter rations risk triggering sub-acute ruminal acidosis (Sara), cutting milk from forage and reducing income over feed costs (IOFC).

That is the warning from KW senior nutritionist Mark Scott, who says farmers should choose starch feeds best suited to improving rumen fermentation rather than basing their decision on feed costs.

Starch plays a key role in supporting milk yields and protein levels, as well as helping reduce negative energy balance in early lactation, but can also disrupt fermentation efficiency by lowering rumen pH, he explains.

See also: Guide to taking and analysing silage samples

“For example, confectionery blends offer a more balanced supply of energy than rolled cereals thanks to a high sugar and oil content alongside the starch.

“But where silages are particularly acidic and low in fibre, switching most of the starch in the ration to the more slowly fermented maize meal or caustic soda-treated wheat will considerably reduce the risk of Sara.

See also: 2015 silage analysis shows increased risk of acidosis

“The net result will be an increase in IOFC, despite the potentially higher monthly feed bill.”

He adds: “Maximising value from home-grown forage is vital if feed costs per litre are to be minimised and IOFC maximised for the rest of the winter.”