26 February 2021
Lamb mortalities in Welsh flocks are mostly preventable if ewes are fed correctly pre-lambing, particularly in the final three weeks as this has a significant influence on colostrum supply and quality.
Most lamb losses occur in the first 48 hours of birth with risk factors ranging from low birthweight and difficult births to poor hygiene and litter size.
Some are the result of decisions and actions taken in the weeks leading up to a lamb’s birth, say vets Cath Tudor and Miranda Timmerman, of ProStock Vets.
They provided advice to farmers on how to reduce losses during a virtual workshop supported by the Welsh Government, Farming Connect, Lantra and NADIS.
If a lamb is born at its optimum weight its chances of survival are much higher. For a twin lamb from an 80kg lowland ewe that target is 3.5-4.5kg.
Small lambs are more likely to die – ewe nutrition in the weeks leading up to lambing is crucial, particularly in the three weeks before lambing as this is the critical time for ensuring the ewe has a good supply of high quality colostrum and milk.
“Late pregnancy nutrition is crucial to everything,’’ said Ms Tudor.
“The most useful thing a sheep farmer can do is to scan ewes and feed to match the number of lambs she is carrying. Test forage and ration accordingly for energy, protein, minerals and rumen health.’’
Metabolic profiling ewes three weeks before lambing is useful too – farmers registered with Farming Connect can apply for funding towards the cost of this.
A newborn lamb needs an adequate intake of colostrum. To get the best from the antibodies in colostrum, lambs need to consume 50ml for every kilo of liveweight at every feed.
For example, a 4kg lamb will need 200ml at every feed and will need four feeds in the first 24 hours, with the first feed ideally within two hours of birth.
“If a lamb takes colostrum in the first two hours it will get a high level of antibodies in its system – after six hours it is not as effective,’’ Ms Tudor explained.
She recommends dam’s colostrum as the ‘gold standard’ and, as a second option, colostrum harvested from another ewe; if neither are available, colostrum from cow’s milk is her preferred choice over and above artificial colostrum.
If a lamb is comatose and under six hours old, revive it with a heat source and then stomach tube with colostrum.
If older than six hours, energy levels will be very low and an injection of glucose is needed as a first course of action.
“When injecting glucose, go an inch to the side of the navel and an inch down,’’ advised Ms Timmerman. “Use a one-inch needle and go in at a 45 degree angle.’’
Once this has been administered, revive with heat and tube with colostrum.
The most effective way to prevent navel ill is to dip or spray navels with strong iodine after birth and again 2-4 hours later; this dries and disinfects the navel.
A difficult birth is another reason why lambs die. To ensure the best possible outcome from these, Ms Tudor advises pulling “slowly, surely and with lots of lubricant’’.
A specific non-antiseptic non-drying lubricant is money well spent, she adds. “It is far better than something like washing up liquid which is a drying agent.’’
Straw is expensive but it has a significant cost benefit compared to losing lambs.
“With lamb prices at £110 - £150, saving one lamb is the same cost as a tonne of straw. Don’t tell me that straw is too expensive!’’ said Ms Tudor.
Diseases and bacterial loads are reduced if stocking densities are low, pens are cleaned between lambings and with outdoor lambing.
Cleanliness is key to preventing joint ill. “Implement a rigorous cleaning and disinfection protocol for lambing pens,’’ said Ms Timmerman.
She advises using gloves for lambing and ensuring that tagging equipment and castration rings are scrupulously clean, even soak in iodine before use.
To prevent navel ill, dip or spray with a strong iodine, ideally a 10% product, immediately after birth. Repeat after 2-4 hours and, if not dried up, repeat daily.
Vaccinating for clostridial diseases is vital – lamb dysentery, tetanus and pulpy kidney are all preventable with vaccination; a vaccination for these costs as little as £0.70 per ewe.
Coccidiosis, which is caused by protozoa spread in faeces, also claims a high number of lambs.
To protect lambs, Ms Timmerman advises managing lambs of different ages in separate groups and avoiding sudden exposure to contaminated fields.
Minimise faecal entry to feed and water and identify areas of high risk, such as around troughs.
Strategies for preventing all risks that could result in lamb losses are cheaper than income lost from those lambs, said Ms Timmerman.
“Good colostrum, vaccination, straw and nutrition cost much less than losing a lamb and, if you know you are doing your best for your sheep, it puts you in a better mindset than wading through problem after problem at lambing when there is a lot going on,’’ she said.