Good growth on farms

Press, 21 October 1983, Page 28

Good growth on farms

o, LIVESTOCK MONITOR

Conditions in Canterbury for pasture growth have been excellent during the past month and with the recent rainfall growing conditions should continue to be favourable in the next two weeks. Some farmers are consid-

ering closing more paddocks for hay, according to the Ministry of Agriculture and Fisheries.

The following information on animal health and production has been compiled by the Lincoln animal health laboratory, the M.A.F. at Darfield, and the Malvern Farmers’ Veterinary Club. The weight of ewes in the Darfield monitor flock this week was 48kg, a drop of 2kg during the last month. The ewes now have 4-6-week-old lambs at foot.

The hoggets weigh 39kg, a slight increase, but still less than the target of 41kg. While the quantity of grass has been adequate, the dry matter content has been lower, according to the M.A.F., and weights are not increasing as expected. As well the ewes, which had not been drenched as adults, appear to be suffering from a parasite problem, so ewes and lambs should now be drenched.

To help flock liveweights during the year, farmers with scales should weigh their ewes at weaning and their hoggets at shearing. Charts showing seasonal liveweight targets are available from the M.A.F. SHEEP

© Planning for the control of internal parasites is important at this time of year. Research and experience over the last two seasons have resulted in the de-

velopment of preventive methods of worm drenching which enable no extra drench to be used but givemuch better control over the sub-clinical effects of parasites on production, as well as preventing obvious clinical diseases such as scouring, ill thrift and death.

Ideally a drenching programme should be integrated with the use of safe pasture after drenching. This is only possible to a limited extent on most properties with high stocking rates and poor summer pasture growth. A programme involving the use of drench only relies on breaking the parasite life cycle, therefore the timing of anthelmintic use in such programmes is very important. If drenching is delayed seven days after warm wet weather conditions, significant pasture larval contamination can occur and cause problems later in the season.

In most cases preventive drenching will involve three drenches at intervals of 21 days, starting at weaning, followed by 2-3 drenches at intervals of 28 days. The programme may start 21 days before weaning in some cases.

Generally only one anthelmintic family should be used per season since this will minimise the chance of worms developing resis-

tance to more than one chemical family. Most modem anthelmintics are fully effective against all the important parasites of sheep, including lungworm. Ideally, such preventive drenching programmes should be modified to suit individual properties and season. Farmers should consult their vet for advice. ® As in previous years the laboratory has diagnosed a number of cases of hairy shaker disease in lambs this spring.

Contrary to popular belief this disease is not caused by a deficiency of iodine. Hairy shaker disease (known as border disease in the U.K.) is caused by a virus. The effect on the lamb depends on the stage of pregnancy of the ewe when she is infected. Early infection can result in a high percentage of dry ewes and abortion. Late infection leads to “hairy shaker” lambs or lambs without symptoms. The disease is probably widespread but fanners can minimise the chances of an outbreak by ensuring that no. new stock are mixed with their ewe flock within a month either side of tup ping. DAIRY CATTLE

® There has been an increase in the incidence of 'downer cows this season. Cows have been going down

before calving and many have not recovered. In most cases low herd magnesium levels were found, combined with poor general nutrition. As emphasised in the last monitor, if in doubt farmers should get their herd magnesium levels checked by a vet and supplement accordingly. DEER

© Antler velvet growth is well advanced with button casting being early on many properties this year. The first of the mature stags may be ready to harvest now. Generally it is better to remove the antlers slightly early, while the bulb is still in the flat stage, than risk the possibility of downgrading for the sake of a few grams of extra weight. FITCHES

® One. property in Canterbury has experienced an outbreak of distemper but fortunately losses were small.

Fitches are more susceptible to this disease than dogs, therefore distemper on a fitch farm could have disastrous consequences.

In the wake of last month’s reported outbreak of this disease in Auckland dogs, fitch farmers would be wise to check that their animal’s vaccination records are up to date.