Following an unusually mild autumn, grass growth was recorded to be over twice the seasonal average for October and November in 2015. Although autumn grazing tends to be low in dry matter, it allowed ewes to maintain condition which has resulted in high scanning percentages for many farmers heading into 2016 lambing season.
The main aim for farmers now is to turn prolific scanning results into a productive and profitable lambing season.
Lamb finishing rates range significantly from 75% to 90% in UK flocks. This represents a significant financial loss to a farm business and industry. Last season, Farming Connect Know Your Flock + groups recorded lamb sales ranging from77% to 93% compared to scanning results. Farmers should be aiming to sell 90% of the number of lambs scanned to achieve the best returns.
How can I minimise lamb losses?
Whilst extreme weather conditions will inevitably increase lamb losses, the majority of lamb deaths are associated with poor nutrition and disease. Evidence suggests that ewes in poor condition at lambing have; smaller lambs, reduced interest in their lambs, insufficient colostrum, increased disease problems and high worm burdens.
Targeting ewe condition and health
Ewes should be at target condition score 2.5 to 3 at lambing (2 to 2.5 for hill flocks). Adequate ewe nutrition during the last six to eight weeks of pregnancy, when 75% of foetal growth occurs, is essential for appropriate lamb birth weights. Ewes also need appropriate energy and protein levels within their ration, especially protein, to ensure high quality colostrum and adequate lamb growth.
It is also important to note that ewes can only consume 2-2.5% of their body weight in dry matter; furthermore this volume is reduced by up to 10% in the final two weeks of pregnancy as the uterus suppresses rumen space. High quality forage is therefore essential, and undertaking forage analysis will ensure the ration is fulfilling the ewe’s needs. Also it’s important to consider forage palatability, high levels of wastage around feeders and signs of ‘burrowing’ into the bale indicate poor palatability.
Separating ewes at scanning into different groups on the basis of litter size and body condition will ensure ewes are fed according to their needs and will avoid wasteful overfeeding of single bearing or later lambing ewes. This will also reduce the risk of twin lamb disease (pregnancy toxaemia), where ewes suffer from energy shortage within the diet. However, we may see an increased incidence of twin lamb disease this year as more ewes are carrying multiple lambs and recent high rainfall is affecting grazing quality.
Poor nutrition is only one of several factors that cause poor condition in ewes. Liver fluke has been a major issue for many flocks and continues to be as seasons become wetter. Infectious abortions also pose a threat to flocks and are most common after 100 days of pregnancy.
Getting it right at lambing
Good hygiene, from lambing the ewe to post lambing lamb care, is key to avoid infectious diseases spreading throughout the flock. Joint ill, navel ill and watery mouth are all infections of lambs that are associated with poor hygiene along with mastitis and metritis infections for ewes. Thorough washing and disinfecting of lambing equipment and facilities after use is essential along with ensuring that the bedding is clean and dry.
Within the first 15 minutes of a lamb’s life, the navel should be fully immersed in strong veterinary iodine and repeated two to four hours later. Lambs must also ingest sufficient amount of colostrum, 200ml/kg during the first 24 hours of life and 50ml/kg must be ingested within the first two hours. The lambs small intestine is able to absorb the antibodies from the colostrum within the first six hours of life which provides the lamb with up to six weeks of immunity.
Lambs can quickly lose body heat unless they receive an adequate supply of colostrum, which results in hypothermia. Lambs with mild hypothermia (body temperature of 37.5 - 39°C) should be dried and fed 120-240ml of colostrum by stomach tube every two to four hours until they recover. Lambs with severe hypothermia (body temperature below 37°C), if less than five hours old, should be dried and warmed up to 37.5°C and then fed colostrum. If the lamb is more than five hours old and is able to hold its head, the lamb should be fed colostrum by stomach tube and warmed up. Glucose should only be injected into the abdomen if the lamb is over five hours old and unable to hold its head, then warmed up to 37.5°C and stomach tubed colostrum.
Record your losses
Recording lamb losses can be very beneficial especially when planning ahead for subsequent lambing seasons. Noting when lamb deaths occur (i.e. pre-lambing, at lambing or post lambing), date of birth, number of lambs within the litter and cause of death (if known) can allow you to identify where improvements can be made. Discussing this data with your vet may allow you to identify any underlying issues and develop a cost effective management plan.