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PARAGON VETERINARY GROUP
ISSUE 43
Livestock NEWS BVD: why to eradicate when you vaccinate
Join us... Merry Christmas and thank you to all our loyal clients, new and long standing, for entrusting us with the care and veterinary support of your herds and your flocks. I hope you will be able to join us for a drink on Thursday 12th December 7.30-8pm at the Booth & Shoe, Greystoke or Thursday 19th December 7.30-8pm at The Crown, Broadfield, Southwaite.
With various European countries tackling BVD problems in their cattle population rather successfully and Scotland and the Orkney Islands getting good results in their BVD eradication approach, soon there might be similar BVD control programmes starting in England and Wales.
DECEMBER 2013
Contact us: PARAGON VETERINARY GROUP CALDEW VETERINARY GROUP Carlisle House, Townhead Road, Dalston, Carlisle
Tel: (01228) 710208 vets@paragonvet.com TOWNHEAD VETERINARY CENTRE Townhead Veterinary Centre, Newbiggin, Stainton, Penrith, Cumbria CA11 0HT
Tel: (01768) 483789 So‌.what’s all the fuss when most cattle farms are (and sometimes have been for years) vaccinating against BVD anyway. Why eradicate when you vaccinate? BVD is a multi-faced disease, with various strains, clinical signs, persistent carriers (PI) and ways of transmission. Therefore vaccination, if handled and administered correctly, seems a very appropriate way of protecting individual animals and the herd from severe clinical BVD-disease. This has been confirmed by research where BVD virus has been squirted up the nose and even injected into the blood at doses 10.000x normal encountered amounts with vaccinated animals showing no signs of BVD disease. However when vaccinated cattle are being brought in contact with normal amounts of BVD virus for several weeks/months, as is
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the case when persistently infected animals are present in a herd, the vaccinated animals did seroconvert to the natural virus with some animals showing severe clinical signs. This suggests that vaccinated animals are well protected against one-off BVD encounters, as is the case with over the fence contact of neighbouring infected cattle, but, that when vaccinated cattle are being housed with BVD-persistent-carriers vaccination might not be as effective as one would wish for. Therefore a search for persistently infected BVD carriers (PI) within the herd, either through bulk milk and/or blood sampling and getting rid of persistently infected animals (eradication) would be advisable if one is vaccinating or wants to start vaccinate against BVD.
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LIVESTOCK NEWS
DECEMBER 2013
Calf rearing Further to last months brief look at calf milk replacers and their effect on calf growth rates we take a look at other nutritional factors involved in calf rearing.
Christmas Turkeys Many farmers rear a few turkeys for Christmas and it is an interesting sideline. A couple of points are worth bearing in mind in the run up to the festive season. Birds have a highly efficient respiratory system (most of them need it to get enough oxygen into the system to fly, although obviously this does not apply to turkeys!). This means that they are also very good at filtering pathogens from the air and are highly prone to respiratory infections. As the weather cools down it is vital to ensure that ventilation of sheds remains adequate but the birds are not exposed to draughts. Many people use straw as a constituent of the litter and this must be of good quality and remain dry as it can promote the growth of Aspergillus, a fungal infection in the air sacs. Another possible cause of respiratory problems is infestation with gapeworms. Earthworms can carry the parasites so birds with access to soil, particularly land that has had turkeys or chickens on in the past may be affected. An in feed wormer is available (FlubenvetÂŽ). This needs to be given for 7 days and has a 7 day meat withdrawal so timing is vital to ensure birds are drug free before slaughter. If you have any turkey queries, please speak to Anne (01228 710208).
In order to reach breeding target weights of 400kgs at 400 days, and then calve at 700 days at around 650kgs there are many factor which contribute to this. Research has shown that for every 70kg of addition body weight at calving, an average additional 1000kg of milk could be expected. Increasing growth rates when they are young gets you the best return on money spent, as the calves are not eating the vast quantities of feed that they do when older. On average, for every additional 100g of daily gain during the first 2 months of life, about 225kg of extra milk in the first lactation could be expected.
These should be offered ad lib from a few days old until weaning.
The provision of solid feed is crucial in rumen development allowing these animals to achieve their full potential. Feeding pellets instead of course mix has been shown increase intakes and improve growth rates when compared to a course mix. A good starter pellet should be around 18% CP, 8-10% Fibre, <4% fats/oils.
Also, there is a common misconception around the availability of water when calves are on milk. Think of milk as a feed and water as a drink. Fresh clean water should be available at all times for pre weaned and weaned calves. For every 1 kg of concentrate eaten a calf will consume 5 litres of water. This is a requirement by law.
In addition to concentrates the provision of hay/straw is highly recommended. This will help increase rumen pH and avoid any acidosis as a result of feeding a highly digestible milk and concentrate diet. One issue with feeding ad lib forage is the amount of room that they take up in the rumen. The most successful way to overcome this is to chop the hay/straw down to 1â&#x20AC;?(2.5cm) in length. This will still provide enough fibre but you wont end up with 'gutty' calves that won't drink their milk or eat their cake.