6 September 1996

Wet weather brings risk of foot-rot

CATTLE

MILK fever cases have increased markedly as cows approach calving. This is particularly so where producers are extending the grazing season without supplementing grass to achieve the right mineral balance, says Cumbrian vet Neil Frame.

The flush of autumn grass is likely to be low in all minerals whereas dry cows need a high phosphorus, low calcium ratio in their diet between six weeks and three days pre-calving. This restricts calcium available and the cows digestive system works harder to absorb the calcium she needs. At three days pre-calving her system is primed to absorb all available calcium and a high calcium diet can be fed to satisfy the increased requirement at milking.

High risk cows – third or fourth calvers – should be identified during the dry period and given subcutaneous injections routinely as calving approaches.

SHEEP

A prolonged wet period combined with temperatures above 10C (50F) could lead to outbreaks of foot-rot, says David Henderson of the More-dun Foundation. Pasture at this time of year is likely to stay wetter longer, causing the skin between the cleats of the foot to denature. This allows in Fusobacterium necrophorum, which causes scald.

When a second bacterium – Dycholobacter nodosus – is present scald becomes foot-rot. To treat stand all sheep in a 10% zinc sulphate solution for at least 10 minutes, consider vaccination if flock problem is serious and treat severe individual cases with antibiotics.

PIGS

As the day length shortens rapidly, the sows hormone cycle is affected and autumn infertility can occur, reports East Yorks vet Mark White.

Abortions can rise by 4% and farrowing rates fall by over 10%. To counter this extend the day length by providing lighting for 14 to 16 hours a day, he advises.

To prevent foetal losses caused by energy deficit, which can occur during the coldest part of the night, sows need an extra 0.5kg of feed. &#42


Watch out for:

&#8226 Erysipelas

&#8226 Respiratory disease

&#8226 Scours in piglets


Watch out for:

&#8226 Ketosis

&#8226 Husk

&#8226 Thin cows


Watch out for:

&#8226 Stomach worms

&#8226 Sheep scab

&#8226 Blowfly strike

Rain is increasing foot-rot risk.