Pregnant ewes in the last six weeks of gestation are a hard-working bunch. At this stage of the year, the housed ewe should be on ad-lib silage and supplementary minerals as her energy demands increase by the day.
Scanned ewes with twins or triplets are to the pin of their collar as the multiple fetuses in the womb need all the nutrition they can get. Protein is required for tissue and muscle formation of the unborn lambs and calcium and magnesium is swallowed up as the bones grow.
In the first half of pregnancy, we see much less mineral uptake by the lambs but from this stage of winter until the birth of the lambs, the calcium drain increases by the day.
Meanwhile, the mother must also prepare for the feeding requirements of the lamb from birth up to weaning.
The mammary gland goes through stages of blood engorgement as it fills and relaxes, and fills again in preparation for lactation.
But our focus as carers of pregnant ewes must be on production of top-quality colostrum and a lively newborn lamb.
Subtle changes in husbandry can ensure improved quality of colostrum. Ewes should be fed a mineral mix in accordance with the results of the pregnancy scan. The twin and triplet group needs more mix.
Conditions such as twin-lamb disease and calcium deficiency not only threaten the life of the pregnant ewe, they also have a hugely deleterious effect on the quality of the colostrum produced if the ewe survives to lambing day.
Two to three percent incidence of twin-lamb disease is an indicator that more than 60pc of the flock is far too low in energy and will have low-quality colostrum as a result. In other words, these conditions have an iceberg effect, where a few clinical cases indicate a much deeper problem under the surface.
We can also prime the colostrum with vaccination programmes that ensure maximum antibody production in the ewes' first milk. Even a simple vaccine against the clostridial diseases should be aimed to give highest disease protection to the pregnant ewe, as opposed to aiming at having maximum response in mid-summer.
Your farm vet will best advise how to target the relevant vaccinations in your own flock, but we can say here that whatever protection your ewe has now, this is exactly what passes over to the newborn lamb in the colostrum.
The birth of lively lambs (outdoors if possible) to mothers with two viable glands and teats is the first good strike of the ball, but the second good strike is excellent-quality colostrum to feed their lambs.
The quality of the colostrum is measured by the level of immune-globulins in each millilitre. The immune-globulins are the mother's antibodies against all the diseases she has met on any farm. The antibodies are further added to by any vaccinations she will have received.
It is quite simple to test the colostrum using the ZST test. Your vet can do that at the in-house laboratory at the clinic, or he/she can send it to the nearest regional laboratory in your area. Results are fast and relatively inexpensive.
We must also remember that colostrum is also a vital source of immediate energy to the newborn. If the immune-globulin level of colostrum is low, then all parameters of the colostrum are low. Hence, the lambs born to mothers on an inadequate diet will be weak and receive poor immunity in the colostrum. They also receive sub-optimal levels of energy. That's a sure recipe for disaster.
Our focus this month is to ensure that top-quality colostrum is produced by the expectant mothers. Have another look at body condition score and another look at that diet.
Peadar Ó Scanaill is a veterinary practitioner in Ashbourne, Co Meath, and is a member of the food animal committee of Veterinary Ireland. Email: email@example.com