Don’t let SARA spoil your new year: watch out for key symptoms
15th December 2023
In the UK it is estimated that a quarter of high yielding dairy cows suffer from sub-acute ruminal acidosis (SARA). David Bonsall, animal nutrition technical manager at Omya says it gets worse over the winter when a large percentage of the UK herd is housed, but there are management changes farmers can make to prevent and cure it.
“Ideally SARA should be minimised and when recognised acted upon quickly,” he says. “Often the most noticeable symptom is a loss of appetite leading to poor body condition which of course adds its own complications. Cows with SARA also tend to scour so changes in dung consistency should be noted. The other big issue is lameness, locomotion issues due to sole ulcers and bruising are often seen and one of the causes may be SARA.”
SARA is caused by the accumulation of volatile fatty acids (VFAs) in the rumen. As concentrate is fermented in the rumen volatile fatty acids are produced. If this happens quickly, as it does with high sugar and starch rations, then the pH in the rumen drops. An animal is said to be suffering from SARA if the pH stays low (between 5.2 and 6) for a prolonged period each day.
“The cows most at risk of SARA are those fed on high concentrate diets for higher yields,” David explains. “These are often housed, high yielding herds, but any diet high in sugar and low in fiber causes a risk – even spring grass can be an issue. Farmers who are aware of this risk will be vigilant for the symptoms, but it is possible to protect against SARA with very little cost or impact on feed management. OmyaFeed C MgO is an advanced formulation feed supplement which costs less than 7p per cow per day and will prevent SARA in healthy cows and cure it in those suffering with it.”
OmyaFeed C MgO is a compacted product made from micronized ground calcium carbonate and magnesium oxide. In independent trials comparing the efficacy of OmyaFeed C MgO with a standard sodium bicarbonate mix, scientists found that cows supplemented with OmyaFeed C MgO spent fewer hours per day with rumen pH below 5.8 than those fed with the standard mix. Milk proteins were higher, giving a better fat:protein ratio and yields and fat content were unaffected.
“Many farmers use sodium bicarbonate as a rumen buffer,” says David. “But there are a couple of issues that farmers should be aware of. Firstly, sodium bicarbonate has to be fed at high rates, perhaps 250g per cow per day, and secondly, it doesn’t provide any long-term buffering effect because it is so soluble. OmyaFeed C MgO is fed in much smaller doses and buffers the rumen pH to the correct level enabling fibre digesting bacteria in the rumen to perform well.”
OmyaFeed C MgO offers a cost-effective replacement for standard sodium bicarbonate mixes because only 130g per cow per day is required to keep SARA at bay. This leaves space in the ration for either other foodstuffs or to allow an overall cost reduction for the farmer. As well as rumen buffering, it provides essential calcium and magnesium nutrition.
“Another key benefit of OmyaFeed C MgO is its readily available supply of calcium and magnesium,” confirms David. “These are particularly important nutrients for dairy cows, given that each litre of milk contains 1.2g of calcium and magnesium is essential for many physiological processes including milk fat production. Trials have shown that absorption of calcium and magnesium is more efficient with OmyaFeed C MgO, up to 60% more for magnesium compared with the standard mix.”
OmyaFeed C MgO delivers the same or better performance as a standard sodium bicarbonate mix but at a lower cost.
“At less than 7p per cow per day, OmyaFeed C MgO offers a great opportunity for farmers to manage the welfare of their herd at the same time as improving their own profitability,” concludes David. “Because it’s a compacted product, it’s low in dust and can be mixed easily in the ration without settling. Farmers can add it to either concentrated feed or to silage, making it very easy to feed. There’s no reason why cows need to suffer from SARA these days, when curing and preventing it is this straightforward.”
OmyaFeed C MgO is available in the UK and Europe and can be purchased as a straight supplement by farmers or in blends from selected distributors. For more information visit www.omya-agriculture.com or contact David Bonsall directly.
