26 January 1996

Time to ration out forage

After 1995s drought many farmers were left with the problem of how to ration lower than average amounts of often unusually high dry matter silage. Jessica Buss and Robert Davies reports

NOW is the time to re-assess forage stocks before its too late to buy in straw to eke out any shortfall in supplies.

This is the message of Oxford-based ADAS consultant Chris Savery.

He advises checking how much forage is left by measuring the clamp volume and then using its density to calculate the tonnage available and how long it will last according to daily use (see box).

"Try to leave a safety margin because a turnout planned for mid-April may be delayed," he says. "When stocks are short, buffer feeding may have to be sacrificed.

"In some cases forage use may be slower than anticipated, either due to late autumn grazing or higher dry matter silage producing extra ensiled crop. So, more dry matter may be left in the clamp now than when silage is wetter."

He claims the options for reducing forage use vary but that welfare codes requiring animals to have unrestricted feed must be met. In this respect extra straw may need to be offered.

"The ration still needs to be balanced and sufficient water provided. But make any necessary changes gradually to allow the rumen to adjust over seven to 10 days," he says.

&#8226 Insufficient forage.

He advises buying spare silage or straw from neighbours. "Include up to 1.5kg, of chopped straw in fresh calvers rations or 2kg of caustic treated straw, but beware it may reduce yield and increase milk fat," he says. "Late lactation cows can be fed almost all straw with increased concentrates to maintain yields.

"Alternatively put dry cows and heifers on straw if they are not already."

&#8226 Milk fat too high, protein too low.

When straw is already being fed check that it is needed and when possible take it out of the ration, advises Mr Savery.

Feeding more concentrates may reduce fat and increase protein but will also stimulate yields. Ensure fibre in the diet is adequate. A change to highly digestible concentrates such as finely ground cereals can also reduce milk fat, he claims.

However, when over quota feed less concentrates, he advises. This will increase fat, but reduce yield and should maintain milk proteins.

&#8226 Cows are failing to reach peak yields or having fertility problems.

Mr Savery says this is often due to poor quality forage or failing to feed enough energy. Succulent feeds such as brewers grains and citrus pulp can make up for a deficiency in forage. Alternatively, offer extra compound feed to maintain a balanced ration.

However, some fresh calvers may be failing to reach peak yields due to poor cow condition and under-feeding during the dry period, he warns.

&#8226 Late lactation cows could have their concentrates reduced but forage stocks are too tight.

Add straw to the ration to make grass silage last for priority cows, but this means maintaining concentrates to cows fed straw. Unfortunately other bulk feed and by-product sources are in short supply.

&#8226 Silage is being wasted.

Wastage is always too high so there is generally scope to improve, he claims. "Keep a tight silage face, a clean floor and check that all the feed gets into the cow trough not onto the floor to be trampled."

Clamp 2.5m deep

Grass silage DM%kg/cu m