Stomach worms and nematodirus affect the lining of the stomach and intestine which reduces the sheep’s absorption ability and as a result causes scours.
They cause loss of appetite and poor live weight gain. When it comes to worm control it is all about reducing exposure to large volumes of worms.
Lungworms predisposes the lambs to pneumonia, causes short sharp coughs, reduces milk output in ewes and reduces live weight gain in lambs.
Lambs should be dosed at 6, 9 and 12 weeks of age for stomach worms (Keelogane, Flexiben, Combizole or Ovimec). If there are issues with nematodirus an additional dose at 3 weeks should be carried out.
With all the wet weather over the winter and recent month liver fluke are going to be an issue. Liver fluke causes ill-thrift, poor productivity and condemned livers. While acute liver fluke can cause death in sheep. Adult sheep should get Keelogane (at the fluke dose level) or Fasifree, especially those on wet ground, where the mud snail can be plentiful.
Chart below highlights the effects on performance and output
|Parasite||Effect on performance||Reduced output|
|Stomach worms||Scour, reduced intakes, poor feed conversion efficiency, longer lambing interval and later development to puberty.||Reduced live weight gain. Untreated animals can graze up to one hour less per day.|
|Lung worms||Coughing, difficult breeding, reduced performance, susceptible to other respiratory problems.||Reduced performance and in severe cases, even death.|
|Liver fluke||Ill-thrift, reduced performance, condemned livers and reduced health status.||Feed intake can be reduced. Reduced daily live weight gain.|
|Rumen fluke||Watery scour, dehydration, poor intakes, weight loss and reduced performance.||Up to 10% reduction in performance in severe situations.|
|Lice||Irritation and distracted from feeding.||2-5% reduction in performance|