Weather challenges remain

Heavy rainfall and below normal temperatures continue to stifle any significant rise in grass growth and any real prospect of getting fertiliser applied. Some farms are getting by OK, with growth just keeping ahead of demand, but for a rising number there is no other option but to supplement with concentrates.

Detailed supplementation rates were listed on last week’s sheep pages but as a rough guide ewes suckling twin lambs and grazing an average supply of grass (4cm to 5cm) will benefit from supplementation of about 1kg per head daily. This will help to conserve grass supplies. Where no grass is available, rates will nearly need to be doubled, along with offering a supply of good-quality silage or hay. Rates can be reduced by about 30% (ewes in poor body condition) to 50% (ewes in good body condition) for single suckling ewes.

For five- to six-week-old lambs it is more economical to offer supplementation in the form of creep feeding. This does not mean that feeding concentrates to ewes should stop, rather that supplementation can be reduced. Offering lambs more palatable cooked or crunch rations will promote higher intake. As intake increases and lambs become accustomed to eating, these higher cost feeds can be replaced with high energy standard rations or three to four-way cereal-based rations.

Outdoor lambing

Weather conditions are currently very difficult for outdoor lambing flocks. The forecast remains unfavourable for the coming days with a risk of wind chill in more exposed areas. Keep an eye on the wind direction forecast and, where possible, ensure that ewes have access to shelter from the prevailing wind. If supplementing, target feeding times to the morning and evening, giving sufficient times for ewes and lambs to settle and find shelter before nightfall. Ensuring that lambs receive adequate colostrum will also help in giving lambs a good start and help in preventing chill or hypothermia.

Disease diagnosis

There have been some reports in recent days about abortions in hill and late spring lambing flocks and sudden deaths in lambs aged four to five weeks old. Taking abortions first, any incidence should act as a warning of a potential outbreak, with recommended precautions of isolating the ewe and aborted foetuses/lambing materials.

Many flocks experience an individual or low number of cases in late pregnancy for reasons such as ewes getting hurt or the pregnancy terminating early due to an isolated case of listeriosis for example. Where the incidence exceeds 2%, however, action should be taken including sending the aborted foetus and lambing materials for laboratory diagnosis of infectious agents such as enzootic abortion. Samples must be booked in via your vet, with the potential for an accurate diagnosis helped by swift submission.

Laboratory diagnosis is also important where sudden death occurs in lambs without any prior warning. The death of fast-growing, high-performing lambs is frequently a tell-tale sign of clostridial disease. Passive immunity obtained from vaccinated mothers via colostrum last anywhere from three to 10 weeks post lambing, depending on the clostridial disease strain and the level of exposure on farms. Lambs can be vaccinated from three weeks and, as recommended by the regional veterinary laboratory in a previous article with William Fitzgerald, a full course consisting of two treatments should be administered for full immunity.