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Media Release |
Friday 21 July 2006
Maintaining animal health during winter important
Maintaining animal health after June’s big snow dump is a critical issue for all those farmers affected by the adverse weather.
Farmers in this situation will be looking at a number of factors, particularly leading into lambing or calving, to safeguard their productive base.
From a veterinarian’s perspective, the important issues to maintain the health of stock are around adequate feed, ensuring animals are vaccinated and drenched to guard against disease and parasites, providing appropriate supplements and reducing animal stress.
While some mixed cropping farmers near the Canterbury coast are already lambing, those in the areas most heavily affected by the snow will not start lambing until late September. For them, the priority is to maintain ewe weight and condition over the next six to eight weeks.
Many farmers have been feeding out since the snow dump, and may not have much feed stock in reserve. At this point, the quality is even more important than the quantity of feed provided to stock. Look for high metabolisable energy feed rather than high dry-matter intake. Ensure stock are fed at least to maintenance at this time of the year, but aim to feed to 20 percent above maintenance if possible.
Introduce grain slowly to avoid overload. A sudden change of diet can be detrimental to stock, causing gut upsets, which will lead to additional problems at this time of year. The key to avoiding this is to try to keep some feed constant through the transition phase; hay or silage is recommended for this. Successfully changing diet for stock can take a week to 10 days for rumen microbes to adapt.
Beware of poorly ensiled silage, which may cause enteric listeriosis. Higher rates than normal of this disease have been reported this winter.
Maintaining stock intake of trace minerals should not be overlooked during the winter. Ewes with insufficient selenium and iodine will fail to produce vigorous lambs.
Feed shortage and stress associated with severe winter weather will raise stock susceptibility to disease and parasites, which is going to be a concern over the next few weeks. Faecal egg count monitoring of the ewe mob from now is advised, to determine whether an extra winter drench is required. Farmers should ensure they are on top of their drenching and vaccination programmes.
Salmonella Brandenburg and Salmonella Hindmarsh are a particular risk. Ewes aborting in late pregnancy could indicate Salmonella Brandenburg. This is a difficult disease to combat and needs to be guarded against by vaccination.
Ewes in poor condition in the face of feed shortage will compromise lamb survival. Monitoring the condition of ewes and maintaining pre-lambing feeding is therefore a priority. Thin ewes deliver small lambs. Hungry ewes wander off in search of food, leaving their lambs at risk. Check the body condition score of ewes. Ewe condition score should be maintained at greater than 2.5 throughout pregnancy. To avoid losing body condition pre-lambing, light ewes should be drafted out now.
This year’s scanning percentages seem to be 10 to 15 percent below last year, which is a reflection on the autumn conditions, not the snow. With fewer lambs born, this will improve lamb survival rates.
To help prevent metabolic conditions at or around lambing, dusting magnesium oxide on the break or silage three weeks prior to lambing at a rate of 10 grams per ewe per day is advisable, but must be administered daily.
Attempting to balance all these factors, while minimising animal stress, adds an additional challenge. Constantly yarding or moving stock can be counter-productive if it raises stress levels, which will compound most of the potential problems listed above. Before yarding, a few days on grain can prime stock to ensure they cope better with the associated stress and time off feed.
Effective risk management is the essence of farming. Severe winter weather brings a series of high risks to animal health. Managing these risks, one by one and in total, is the key to successfully negotiating through a winter such as this.
For more detail about any of the issues discussed above, contact your vet.
Advisory written by: Lyn Graham, Veterinarian, Riverside Vets, Ashburton. Tel: 0-3-308 2321
For further information contact:
Terry Donaldson: Tel: 0-3-358 1747 or 0-27-433 7127
or John Greer, MAF Regional Team Leader: Tel: 0-3-358 1864 or 0-27-432 7692
