Explore options if grazing will be in short supply

29 June 2001




Explore options if grazing will be in short supply

By Hannah Velten

WITH grazing on some units going past its best, buffer feeding of forages or concentrates may be needed to prevent falls in milk yield and losses in body condition, particularly in high yielding cows.

However, this summer many dairy units have low reserves of the traditional, first-choice buffer feed – maize silage.

ADAS nutrition consultant Chris Savery says planning the supply of alternative buffer feeds is essential. "Work out how much quality grazing is available and how long it will last.

"When grass is not there, the nutritional gap must be filled by supplementary feeds to maintain a balanced ration, ensuring milk yield, constituent quality and fertility remain constant."

In place of maize, first-cut grass silage may be an option, particularly when high second-cut yields are expected. "However, when grass silage needs to be rationed whole-crop complements it well. Fermented whole-crop, made from winter wheat or barley needs to be harvested in early July, but alkalage can be taken later," advises Mr Savery.

Straw can be used as an alternative feed, although it is in short supply. But Mr Savery warns against offering only straw to high-yielding dry cows, as its feed value does not support recuperation of body condition before calving.

Other alternatives are straights or compounds. "While concentrates are more expensive/unit than forage, they can bulk out restricted forage supplies. But always check the quality of blends, otherwise the ration may be unbalanced.

"And be aware that concentrate feeds, such as brewers grains, will lower butterfat in milk – a concern for those producing milk on contract."

Once buffer feeding is started, checking milk yields and cow body condition will indicate whether the ration is adequate. High yielders, fresh-calvers and those in early lactation should have priority when buffer feed is limited, he adds.

To maximise the nutritional value of whatever forage is offered, it must be fresh and cold. Forage quality will deteriorate rapidly as temperatures rise, reducing feed energy levels and promoting mould and mycotoxin growth.

"It is easy for clamp faces to heat up. Try to feed twice a day, taking small bites off the face using a shear grab or block cutter to keep air out. Clearing troughs of left-overs is also important."

Buffer feeds are best offered in a confined area during the day, with cows grazing at night, says David Whitaker, vet consultant at the University of Edinburgh.

"In summer, given the choice, cattle are not prone to search out buffer feeding. Bringing them in at noon to eat, until one hour before afternoon milking, ensures intakes. Grazing intakes will also increase during the evening and night because grass is of better quality. Remember, dry matter and sugar content increases in daylight." &#42

BUFFERFEEDING

&#8226 Plan alternative feeds.

&#8226 Prevent forages heating.

&#8226 Offer in daytime.


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