Farm Ireland
Independent.ie

Tuesday 25 July 2017

Battling diseases to keep calves alive

Liam Fitzgerald

The battle against calf mortality doesn't stop at scour. Here are some key points on the other disease challenges facing every suckler farmer at this time of year.

Pneumonia

This is more common in housed dairy calves than suckled calves, as the stocking rate of suckled calves indoors is generally lower. It is associated with poor housing conditions where there is insufficient ventilation and a damp, humid environment. Reduced immunity due to BVD infection is also a contributing factor. Structural changes to the calf house to improve ventilation (without causing draughts) and improving floor drainage and bedding is the first step in prevention. Moving outdoors as soon as possible for spring calving herds provides the best solution. If there is a problem in autumn calving herds, vaccines are available from about two weeks of age but there will be a better response to vaccination in older calves. Vaccination is best done in advance of housing.

BVD

There is a voluntary testing and eradication programme of persistently infected (PI) calves in operation this year. Farmers are encouraged to participate in this programme as a means of identifying BVD carriers and as a way of speeding up the goal of BVD free status in advance of the compulsory programme next year. Farmers who are currently vaccinating against BVD should continue to do so and others should consider vaccination, having assessed the risks such as the level of bio-security, in consultation with their vet. Vaccination should be completed four weeks before the start of the breeding season.

Leptospirosis

It is estimated that up to 70pc of herds have been exposed to leptospirosis and carry the virus. There is a level of active immunity in herds that have been exposed, but this can break down giving sporadic cases in animals of lowered immunity. If leptospirosis gets into a clear herd there is likely to be a high rate of abortions and infertility in the first year. All cases of abortion should be investigated. Treatment involves heavy doses of antibiotics and vaccination of remaining in-calf animals. Herd vaccination should be considered depending on a risk assessment in consultation with your vet. Vaccination should be completed before the start of breeding.

Lepto is different from many of the diseases that we focus on at farm level in that humans can be infected, resulting in flu-like symptoms. It is passed on from the cow's urine and in fluids around calving. Wear an arm-length plastic glove when handling cows at calving and never blow into a calf's nostrils to revive a weak calf.


Grass Tetany

This risk with suckler cows is considered greater in the autumn than the spring. Nevertheless, precautions should also be taken in spring by giving supplementary magnesium. It can be fed as a homemade lick made up of calcined magnesite and molasses or as a proprietary lick/bucket. It can also be fed in a small amount of ration (1kg high Mg nuts/day) or added to a loose meal or put in the drinking water. The risk is greatest where cows go on lush spring grass in cold wet weather. Beef/dairy cross cows with higher milk yield are more susceptible than the pure beef cow.

Indo Farming