Farm First Newsletter February 2012
Treatment of Hypothermia in Lambs
Hypothermia results from a combination of heat loss and starvation. Adequate shelter should be provided outdoors, and indoor pens should be draught-free. Severely affected lambs have an arched back, hollow flanks and a lowered head, with a rectal temperature below 37 °C. If less than 5 hours old these lambs can be dried, warmed to 37°C, fed colostrum, warmed to 39°C and returned to the ewe. However, if they are over 5 hours old they will need an intraperitoneal injection of 20% glucose at a rate of 10ml/kg to help them recover. After this they should be dried, warmed and fed as for the younger lambs.
For further information in this subject, including how to perform intraperitoneal injections, please contact us at the surgery on 01873 840167 or call in for a fact sheet.

Managing the Calf in Cold Weather
Calves which are underfed and energy deficient are at high risk of developing common diseases such as scours and pneumonia. This is because at low or negative growth rates the immune system will no be maturing rapidly enough to provide adequate protection from infectious disease. Calves can be body condition scored (BCS) by feeling for the amount of tissue covering the bones of the back and pelvis. If the BCS of healthy calves 2-3 weeks old is less than a newborn calves, it is likely that they have been energy deficient due to inadequate feeding.
Calves need energy for both maintenance and growth, and energy requirements increase significantly in a cold environment. The Lower Critical Temperature (LCT) is the environmental temperature at which animals start using extra energy to maintain normal body temperature. Calves under three weeks old have an LCT of 20°C, below this they will be using energy to keep warm and when temperatures drop to the 0°C they require 40% more energy for maintenance.
The volume of milk required for maintenance increases significantly as temperatures decline. A calf fed 2l twice-daily at 16°C will gain weight, but below 4°C it will start losing weight. Therefore, more milk must be given during cold weather particularly to younger calves which are only consuming small amounts of solid feed. The energy content of milk depends on the level of milk solids it contains, and the total quantity of milk solids that is fed can be increased in the following ways:

• increase the volume of milk given at each feed or add an extra daily feed
• increase the dry matter content of the milk e.g. mix milk powder at 160 g/l rather than 125 g/l
• feed milk from cows for the first four days after calving to the youngest calves
• use a milk replacer with adequate fat content (20%) in winter
• larger calves require more energy than smaller calves, so feed accordingly
The energy requirements of calves can be reduced with well-designed housing. It is important to strike a balance between providing good ventilation and avoiding excessive air movements at calf level. Provide clean dry straw so that they can "nest" down into it, as body heat is lost rapidly when lying on a damp, poorly-drained bed. Sick calves require additional energy to overcome infection.

Metabolic Profiling of Ewes
If sheep are blood sampled in the last 2-3 weeks before lambing to check their energy/protein and mineral status, the feeding of ewes in the last weeks can be adjusted to better suit energy requirements and avoid problems The BHB levels in groups of 5 ewes carrying singles, doubles and triplets should be sampled to allow increases (or decreases) in concentrates in the last weeks before lambing to be accurately defined. This results in more economic use of concentrates, optimum birth weights and good lamb viability, and allows early identification of ewes at risk of Twin Lamb Disease. Protein feeding in late pregnancy has a significant effect on milk production and therefore lamb health and growth rate. Blood testing will monitor both the longer-term aspects of protein nutrition, and the more immediate question of rumen degradable protein shortages, which are increasingly common in housed sheep.
Blood sampling should be done 2-3 weeks before lambing is due to start so that dietary changes can be made in time. The lab. Fees for testing up to 20 ewes are only £85(including post, packing and interpretation). Magnesium and copper tests are included in this package.

Schmallenberg Virus
This virus has now been reported on four sheep farms in Norfolk, Suffolk and East Sussex. Congenital defects have been seen in aborted and newborn lambs, calves and goat kids. Affected animals have had twisted joints, limbs and neck and are usually born dead or die soon afterwards. Some animals have shown signs of in coordination, paralysis and dullness due to fluid filled sacs in the brain. In adult cattle, fever and reduced milk yield of up to 50% for a week has been reported, in some cases with severe diarrhoea. If you have animals with the suspicious signs on your farm please contact us at the surgery or AHVLA.

Orf Vaccine
If Orf is a problem on your farm now is the time to consider vaccination. We have been informed by the manufacturers of the vaccine, Scabivax Forte, that there are no supply problems this year. The vaccine should only be used if there is a history of Orf on the farm. The vaccine is administered by a special applicator which scratches the skin and injects. A scab should be formed at the site of vaccination within 14 days – if not then they may have not been vaccinated correctly.
In an infected flock, pregnant ewes should be vaccinated not less than 7-8 weeks prior to lambing. If only baby lambs are vaccinated there is a small risk of spread to un-vaccinated ewes. If Orf is a problem in older lambs they can be vaccinated at turnout, or even later. Immunity lasts 6-8 months so the flock should then continue to be vaccinated once a year. The vaccine costs £27.27 + VAT for 50 doses (includes 10% pay at time discount).

Alamycin LA
If you have not vaccinated your ewes against Enzootic Abortion and have had the problem diagnosed in your flock, Alamycin LA can be given between day 90 and 120 of gestation to reduce the number of abortions and shedding of the organism. The dose is 1ml/10kg and a 100ml bottle costs £11.54 +VAT. There is a 10% discount for payment at the time, with larger discounts applied for the purchase of greater volumes.