How to ‘eke’ out silage supplies

THE wet weather will delay turnout out across the country and silage stocks will start to run low, so incorporating a proportion of straw and molasses in the diet will be an effective way to eke out silage stocks.

“While grass covers are increasing, ground conditions mean cows on many farms will be unable to graze effectively, putting pressure on silage stocks as the prospects for turnout are not encouraging,” said Georgina Chapman from molasses blends specialist ED&F Man.

“There are ways to extend silage stocks until cows can go out, with one costeffective option being to consider feeding straw and a molasses blend. This can either be used to replace a proportion of grass silage in the milking diet, or to replace silage totally in heifer and growing cattle diets.”

Trials at the South

West Dairy Development Centre, in conjunction with Kingshay, showed it is possible to successfully replace 2.5kg silage dry matter in dairy diets (around 7-10kg freshweight) with 2.2kgFW of straw and 1kg of a molasses blend.

Assuming cows had been fed 12.5kgDM of silage, moving to 10kgDM of silage and the straw, a molasses blend alternative means every four days on the new diet would save enough silage to allow an extra day of winter housing from current silage stocks.

“The molasses blend plays a crucial role in maintaining good rumen function as well as containing highly rumen fermentable sugars, increasing microbial protein production and stimulating rumen microbes to improve fibre digestion,” she added.

“The blend used in the trial also contained regulated release protein, which releases nitrogen at a steady rate to optimise rumen microbial activity. Coupled with a high sugar content, they promote rumen fermentation and activity and can utilise straw effectively.When implementing a straw-based diet, it is important to provide access to a plentiful supply of clean water.

“The transition from a silage-based diet to a strawbased must be controlled, by introducing more straw into the diet and reducing silage over a few days to give the rumen microbes time to adjust to the new forage.

“Finally, straw is deficient in minerals so additional mineral supplementation could be necessary.

“Incorporating straw and molasses into dairy diets will help minimise the consequences of any delay to turnout,” she concluded.