LIVESTOCK MONITOR

Press, 25 September 1987, Page 15

LIVESTOCK MONITOR

With lambing now three-quarters finished on most properties in the

Darfield district, the lambing percentages appear to be 10 to 15 per cent higher than last season’s, believes Caroline Carter, an agricultural consultant with the M.A.F. at Darfield. Last season’s district average was about 95 per cent. This season’s rise has been attributed largely to the small number of storms.

The average weight of the hoggets on the monitor farm was 43.7 kg, an increase of 3.2 kg since August. The post-lambing ewes averaged 61kg, a reduction of 4kg since late July. Silage is no longer being fed on the monitor farm. While feed is only just adequate at present, paddocks will be shut in a couple of weeks for silage. It is intended to sow two paddocks down in new pasture. Caroline Carter said many farmers were looking at the option of selling Beta lambs. With an upper weight limit of 7kg, the Beta lambs had a potential value of $lB to $2l very early in the season, which provided farmers with a good opportunity of quitting stock early at a good price.

However, farmers who sold Beta lambs during the last two seasons had commented on a large number of ewes with udder problems this year, particularly hard mastitis. Caroline Carter suggested farmers thinking of selling Beta lambs should quit only one lamb from each set of twins so the ewes still had one lamb suckling. Copper deficiency in cattle has been a major problem in some areas this spring, according to Dr Alan Pearson, a veterinarian at the M.A.F. Animal Health Laboratory at Lincoln.

Copper deficiency can show up as ill-thrift and poor milk production. Affected cattle might have light coloured rough coats. Copper deficiency can also result in an increase of downer cows that fail to respond to treatment.

Copper deficiency might be found in combination with selenium deficiency. Laboratory sampling is required to determine which deficiencies ajt involved, and to what

degree. On the basis of blood test results, veterinarians can recommend appropriate treatment. SHEEP

Lamb survival has been good this spring, due to mild weather. The bacteria that cause navel infections and tailing infections also survive well when conditions are mild. Lambs with navel infection become pot bellied, may scour or be lame with swelling of one or more joints (arthritis). They fail to thrive and often die without- treatment. Penicillin injections are effective in treating these lambs, but only if the treatment is given early.

Similar bacteria can gain entry through tailing wounds to cause arthritis or spinal abscesses. For these lambs prevention is better than cure.

Tailing should ideally be done in temporary yards and by hygienic methods. Rubber rings are the best method for avoiding these problems, but lambs tailed with rubber rings must be protected against tetanus. They might already have this protection if the ewes on a regular pre-lambing vaccination programme. Otherwise they can be injected with tetanus antiserum at docking.

• Mastitis in ewes is an ever-present problem at this time of year, especially with the move towards Beta lamb production. Ewes that milk heavily are most susceptible. As a precaution, when lambs are weaned the ewes should be given restricted feeding for a week either side of weaning to limit milk production, and paddocks that have contaminated ‘‘camping areas” should be avoided. The most common and serious type of mastitis, often called ‘‘black bag,” usually results in loss of the udder, even with treatment, and can result in death of the ewe without treatment. A less obvious form of mastitis may cause serious udder damage that remains undetected until next lambing when the ewe’s milk production will be greatly reduced.

It is important to treat all cases of mastitis in ewes early for maximum effect.