JANUARY NEWSLETTER 2011

FARM FIRST
January Newsletter
January 2011


A HAPPY, HEALTHY AND PROSPEROUS NEW YEAR TO ALL
We certainly learn from experiences! The cold weather of the past month does not seem to have adversely affected livestock, so I suppose that we learn from this that its best not to keep them too enclosed. Cows especially are amazingly ‘wet’ animals. They produce around 50 litres of water per cow per day in the urine, faeces breath and sweat (ie in addition to the water in milk), and this moisture needs to be taken out of the building. Failure to do so results in increased lameness and mastitis. At a recent meeting the speaker stated that the ideal temperature for a cow is 4C – so unless you are cold she is probably too hot! Increased air flow (and hence decreased humidity) is achieved by giving the cows ample space and by providing vents at the sides and at the apex of buildings.

RESPIRATORY DISEASE MEETING
Thanks to all of you who supported our meeting in December. What were some of the essential elements of being able to rear calves with less than 1.0% mortality and calving at two years of age? There will of course be variations in the feeding regimes depending on availability of waste milk, size of calf etc, but the following is a summary of the major points we learned for the average calf

Once a day feeding.
The calves are given colostrum for the first 3 days of life then fed whole milk twice daily for the first week. They are then changed abruptly onto ‘Once a Day’ powder, simply be feeding them in the mornings only. This is fed this until weaning at 8 weeks, making sure that there is ample water and hard food available. The advantages of the once a day system were felt to be that calves started eating solid food sooner, that pens stayed drier and of course there is less labour. It’s important to check the calves in the afternoons though, and because they are not being fed you have a bit more time to spend with them.

Calf pens
The calf pens comprised 8’ x 4’ sheets of marine ply (some of them 40+ years old, ie the original sheets used by Jim when he set up the system!) attached to gates at the rear and wooden feeding rails at the front. Thick wads of big bale straw are laid in the base, then loose straw on top. Fresh clean palatable straw is added 3 times per week as a forage source and as bedding. Calves are kept in these pens for 1 – 2 weeks after weaning to ensure that they are eating ample concentrates and then the pen sides are removed leaving the calves on the same straw and in the same area. This produces and almost ‘all in all out’ system that minimises infection transfer from group to group. Only under exceptional circumstances do calves change groups.

Pneumonia control
The calves are certainly not free from pneumonia and some treatments are given every year. Post treatment blood samples taken from affected calves this year showed exposure to IBR and RSV viruses. Calves are vaccinated against IBR and the current strategy is to hope that any RSV infection can be overcome naturally, although this position is always under review, and intranasal vaccination at around 4 weeks of age is an option. If an increase in coughing is seen the calves are monitored for feed intake and general respiratory signs. When more than 10% of calves are affected the whole group is injected. Last year the Draxxin was ordered and collected, but by the time it arrived on farm calves were improving and it was not used!
This balance between whether to treat and whether to let disease run its course is never easy. Vaccination is likely to be the safer option, but as with all such options, cost effectiveness is the difficult decision. The Pfizer subsidised blood sampling (£10 per calf for 5 calves) is well worthwhile to determine disease risk, especially in closed herds.

Vaccination
Vaccination is an important aspect in the control and prevention of BRD. Preventing pneumonia will reduce the costs associated with a clinical case of the disease, for example the cost of treatment, risk of spread to other animals and failure to grow/reach targets compared to unaffected calves.
We can vaccinate for the major causes of pneumonia starting with an intranasal vaccine from 9 days of age which will cover for RSV and Parainfluenza 3 viral causes and injectable vaccines administered from 2 weeks of age which cover RSV, PI3 and Pasteurella. We have a range of vaccines which we can use depending on your farming business and depending on the causes of pneumonia. Please discuss with us at the practice to determine the best protocol. Bovipast RSP vaccine can also be administered to dry cows 6-4 weeks before calving to protect the calves via colostral immunity.
It must be remembered that vaccination is part of a control plan and is not a ‘cure all’ for pneumonia. Housing, colostral status and management all require looking at too. Also an underlying BVD problem will affect the chances of pneumonia developing in a herd due to immunosuppressive effects.


JEJUNAL HAEMORRHAGE SYNDROME, JHS
Also known as haemorrhagic bowel syndrome (HBS), haemorrhagic gut syndrome (HGS), or simply haemorrhagic enteritis “hemorrhagic enteritis”, this condition, first reported in North America, now seems to have reached Gloucestershire! Affected cows are extremely ill, often totally collapsed with shock, severe abdominal pain and blood loss into the small intestine. Those that survive this first acute phase will then start passing a mixture of thick stinking dark bloody faeces and mucous. For those cows that do make it, recovery is slow. The cause is unknown, but affected animals are usually higher yielding early lactation animals on higher levels of feed. Clostridia can often be isolated from the gut and some US farms apparently use clostridial vaccination as a means of control. Vaccination is cheap enough, but most herds only have sporadic cases.