New diagnostic service from Intervet pinpoints lambing losses
From January 2007, sheep farmers will be able to benefit from a new diagnostic service from Intervet. Barren EweCheck is designed to help farmers determine the cause or causes of barrenness and reduce unwanted losses.
Contrary to popular belief, the weather and ewe nutrition are not the only reasons why you aren’t getting as many lambs as you could. Whilst abortion is the most obvious cause, early embryonic death leading to barren ewes and weak lambs that die shortly after they are born are also significant contributors to the loss of ewe productivity.
A staggering 33% of lamb loss occurs between tup and scan. In many cases, the cause of these huge losses is an infection in the ewe during pregnancy, which is often responsible for a barren ewe being picked up at scanning. Along with weak and sickly lambs that die soon after birth, many farmers also accept barren ewes and abortion rates of between 5-10%. Whilst research has shown that anything above 2% is worth investigating.
Barren EweCheck is available through the practice and offers free blood tests for toxoplasmosis during mid-pregnancy, typically at ultrasound scanning time. This will help management strategies to be put in place to prevent recurring losses due to toxoplasmosis, and to control other reproductive diseases.
Toxoplasmosis is caused by a microscopic parasite called Toxoplasma gondii. Its eggs are most commonly found in contaminated cat faeces in barns, feed stores, bedding and manure, or directly on pasture. A single cat dropping can contain enough eggs to infect over 100 ewes, and eggs can survive on farm for well over a year.
Toxoplasmosis is just one of many conditions that can affect the number of viable lambs born to a ewe. If the infection is picked up in the early stage of pregnancy it typically results in reabsorption of the developing lamb. A mid-term ultrasound scan is likely to show the ewe is barren, although there may be signs of poorly developing lambs that will either abort or produce weak lambs that die soon after birth. Toxoplasmosis infections picked up later in a pregnancy will usually result in aborted lambs.
Vaccination with Intervet’s Toxovax® will reduce the losses associated with this costly disease.
You may be aware of Intervet’s existing FlockCheck service, which looks at blood samples from ewes after the lambing period is over. Over the past five years, this has shown toxoplasmosis to be present in a large proportion of flocks across the whole of the UK. In 2006 alone, 64% of the 282 flocks tested were positive for toxoplasmosis indicating the level of threat posed by the disease.
Barren EweCheck will show the presence or absence of toxoplasmosis at a much earlier stage than FlockCheck. This allows control strategies to be put in place, or for further investigations to take place to determine the cause of barrenness should the test show ewes are free from toxoplasmosis.
Barren EweCheck should help you get more lambs per ewe. The service will be available from January to April. FlockCheck will also run from March to the end of July. Contact the practice for details of either service.