26 February 1999

Ensure intakes are balanced

BALANCING energy and protein intake is essential when feeding mixed forage to ewes in late pregnancy, warns independent sheep consultant Lesley Stubbings.

Where sufficient forage stocks allow, mixed forage can offer a low-cost alternative to straw and concentrate rations. But high energy and low protein content of maize can lead to two main concerns.

Maize is high in energy and when gorged can lead to a rise in body condition, which can increase the risk of prolapse. Where additional protein isnt provided milk yield and lamb growth will suffer.

"Ideally, mixing maize and grass silage will provide a forage which has a balance of protein and energy to meet ewe requirements. This should be fed for at least six weeks before lambing."

At Moulton College a 1:2 maize:grass silage ration is mixed using grass silage with an ME of 10.9 and crude protein of 14.5%, and maize silage with an ME 11.8 and crude protein of 7.8%. This provides a ewes basic protein requirement and can be supplemented with a 20% protein concentrate to meet individual needs, explains Ms Stubbings.

Where producers want to feed 100% maize silage, a high protein supplement such as soya is needed. As a guide, a 75kg ewe will have a dry matter intake of just over 2% of body weight. Taking into account maize silage moisture content, freshweight intakes should be 5.2kg/ ewe/day at 30% DM. "Supplement silage intake with soya at 100g/kg DM," advises Ms Stubbings.

Forage must be fresh and available throughout the day to avoid congestion at the feed face. Allow at least 15cm (6in) a ewe feed space.

"Dont feed any maize spoilage to ewes. Maizes high pH and ash content increases risk of Listeriosis which can lead to abortion, but will commonly affect the brain. An early sign of this disease is a drooping ear, leading to an affected ewe walking in a circle," she advises. &#42