Farm Newsletter Nov 2003

Sudden deaths in cattle

I sat down and wrote what you are about to read, took it to the surgery for editorial comment by Jonathan, Jamie and Lee and, out of the blue Tony (from Schering Plough) walked through the door and asked if he could hold a meeting about Sudden Deaths in cattle and sheep. Enclosed are some leaflets and details of the meeting. Here are my few words!

We had a spate of Sudden Deaths in July and August both in beef and dairy cattle – some involved groups of cows other incidents were just single animals. It can be very frustrating sometimes to find a reason - the list of causes is long. Here are a few:- Anthrax, Bloat, Cherry Laurel poisoning, Clostridial organisms, Lightening Strike, Pneumonia, Staggers, Yew poisoning.

We recently had a suspected outbreak of Anthrax in a field of cattle. The disease is notifiable which is why you must notify us of any sudden, unexpected deaths. DEFRA pay for the visit and the test is very quick to perform.

The Clostridial bugs cause a variety of delightful sounding diseases – Blacks Disease, Black Leg, Botulism, Malignant Oedema or Gas Gangrene and Tetanus. Outbreaks often occur in specific ‘well known’ fields or in fields where the soil has recently been disturbed – moles or electricity companies! (Tetanus is a Clostridial bacteria and comes from the soil). Often post mortem examination is the only way to diagnose these diseases. The VLA at Thirsk does a cheap but very comprehensive package – about £70 including disposal for a large cow or bull!

There is often little to be done to prevent further cases unless many animals are being affected . Daily injections of the remaining animals with Penicillin may help prevent further deaths. Vaccination of animals being grazed on susceptible pastures is possible.

TB problems in Yorkshire

DEFRA has identified active TB infection on five premises in North Yorkshire. All the infected animals were moved from TB hotspots in the South – West and were identified during on-farm checks. This has resulted in considerable inconvenience (and consequential loss) to the farms involved, because of the imposition of movement restrictions and testing.

Do be careful where you source cattle from. Question dealers carefully, take care in markets and question hauliers regarding mixing of stock, routes taken and sequential pick ups.

Irish fattening cattle have been identified as a risk group for Brucellosis and TB – DEFRA may ask for a post – import check test.

Welfare of cattle in herds belonging to a farm assurance scheme

Farm assurance schemes were introduced to give consumers confidence that food is produced under conditions which meet appropriate hygiene, ethical and environmental standards. The RSPCA’s Freedom Food (FF) scheme is among the best known and sets welfare standards for each species based on the views of an interdisciplinary expert team. In a paper in the Veterinary Record in August Dr David Main from Bristol Vet School and colleagues compared the welfare of cattle in 28 herds in the FF scheme and 25 non - member herds. There were 12 criteria which were better in FF herds – notably mastitis, while there were eight factors that appeared worse!! These included hock injuries and lameness. Apart from coat quality (which was better on FF units) there were NO SIGNIFICANT DIFFERENCES in the proportions of herds in the two groups requiring remedial action. We will leave you to draw your own conclusions!

Lambing Targets

You may remember in the last newsletter we discussed some targets. If you have thrown it away or forgotten them here they are again.

• 100 ewes tupped with 2 or 3 rams over 6 weeks.
• 99 ewes conceive.
• 2 die (hopefully fewer!)
• 2 abort (or even fewer!) so 95 lamb.

This set of figures naturally leads on to lambing percentages. So –

Remember ‘lambing percentage’ is the number of lambs sold per 100 ewes put to the tup.

Large single lambs with big heads experience protracted birth times. They are then often weak and die due to ruptured blood vessels in the brain.

The 70kg ‘textbook’ ewe can eat about 2.5% of its weight in dry matter (DM) ie 1.75 kg per day. At the end of pregnancy dry matter intake falls due to lack of abdominal space. So an energy dense diet must be fed.

The 8, 16, 24 rule of thumb

The average 70kg ‘textbook’ ewe needs:

• 8 MJ of ME per day for maintenance
• 16 MJ at end of pregnancy if carrying twins
• 24 MJ at peak lactation (4 weeks & suckling twins)

A Mars Bar is worth just over ONE MJ, but sheep don’t like them.

Don’t feed more than 0.5 kg of concentrates in a single feed. You cannot expect a ewe carrying twins in late pregnancy eating a diet of poor silage and fodder beet to be able to eat enough in a day to get its energy requirement. This diet has a low energy density and its gut is not big enough to allow it to eat enough.

Twin lamb disease

This usually occurs in the last month of pregnancy in thin or very fat ewes. There is a restriction to dry matter intake caused by excessive abdominal load of either FAT or LAMBS. The ewe is often separated from the flock, easy to catch and may be blind. Some go into convulsions when caught. (They may well be suffering from magnesium and calcium deficiency too).

Treatment – we would give 50 – 100 ml of 40% dextrose into the vein and follow this up with 45ml Collate orally repeated 4 hours later. Collate only needs to be given for 2 days. If after 48 hrs of this treatment the ewe is not bucking up and eating then think about aborting the ewe or asking us to perform a caesarian.

Two thoughts :

1. Treatment of Twin Lambers is often unrewarding!
2. Twin lamb disease should be rare but sadly is not!