Australian Livestock Scanning Services Group

 

19. How to save new born lambs

Management practices aimed at identifying ways of preventing losses of new born lambs have been, and still are, being heavily researched. Scanning to identify singles and twins plays a pivotal role through enabling the different management regimes required by individual ewes to be provided.

Single lambs

Identify the later lambing, single-bearing ewes, at scanning time and manage them so as to prevent their lambs from getting to big in the last days of pregnancy. This is easily done by putting these ewes into their lambing paddock 16 to 20 days after the lambing proper starts.

Later lambing single-bearing ewes, which are put into their lambing paddock at the start of lambing, are grazing on higher quality "lambing pastures" for 16 to 20 days before the first of them gives birth. This practice is the reverse of that required because it increases birth weight, the likelihood of a difficult birth, and subsequent death of the lamb and possibly the ewe as well.

The correct management of these ewes has been detailed above. Additionally, if a supplement is to be provided, it should be provided to the early lambing, single-bearing ewes only. This practice not only saves the later-lambing single lambs from becoming too big, but also saves on costly supplements and valuable pasture.

Additional benefits from these practices include the opportunity of marking and tailing the first born lambs without having to wait until the later lambs are born. This results in a reduction of the mis-mothering that occurs when lamb marking is delayed until the later born lambs are big enough.

Another bonus is that both ewes and lambs from the later lambing ewes can be given some preferential treatment in order to lift weaning weights and to help the ewes regain acceptable weights prior to the next joining.

Twin lambs

The most important factors for improving the survival rate of twin-born lambs are increased birth-weight, reduced mis-mothering, provision of shelter and the reduction of predation.

Increase birth weight
By allocating appropriate quantities of pasture or supplement to the twin-bearing ewes, it is possible to increase birth-weights and survival rates whilst also avoiding pregnancy toxaemia. Another factor that influences the ease, with which twin-lambing ewes can fulfil their daily nutritional needs, is to lamb the ewes in paddocks with short distances to water.

Reduce mis-mothering
Mis-mothering is reduced whenever ewes, on the point of birth but not yet having given birth, are prevented from interfering with ewes in the process of giving birth. This is most easily achieved by reducing the number of ewes in lambing mobs of twin-bearing ewes to as low a level as possible. As mob size is reduced, there are fewer ewes lambing in the same hour of the day less interference and thus, higher twin-lamb survival rates, Fowler (1989).

Fowler DG (1989) Management strategies for high fecundity flocks. DAN 32S Final Report Australian Meat and Livestock Research & Development Corporation.

This practice may necessitate an increase in the number of ewes in the lambing mobs of single-bearing ewes, but this need not be a problem. It is known that the number of ewes in a lambing mob, in which all ewes are known to be single-lambing ewes, does not increase mis-mothering until mob size reaches about 500 ewes.

Electric fencing can be used to create additional lambing areas. This fencing will not prevent lambs from re-joining their mothers. Starvation is often the result for a lamb away from mother on the opposite side of a permanent fence. Any practice which keeps the twin mother with her lambs will raise lamb survival.

Additionally, any factor that increases the privacy for the twin-lambing ewe will reduce the influence of mis-mothering. Areas which might provide privacy include;

  1. Paddocks where the pasture stands high enough (tussocks).
  2. Gently undulating paddocks that have hollows and fallen timber.
  3. Paddocks with no interference from passing farm or road traffic.
  4. Mis-mothering can be increased when mobs of twin-lambing ewes congregate around self feeders, but this becomes less of a problem as the number of ewes in the lambing mob is reduced.

Shelter
Paddocks that provide privacy, mostly also provide shelter. Clearly, the best paddocks for shelter are those described as “warmer”, have had a history of higher twin-lamb marking percentages from previous scanning /lambing activities, and are those where shelter belts have been planted. Localised weather patterns can be studied to select the "best" time of lambing.

Predation
Twin-lambing ewes are more susceptible to predation because it more difficult for a ewe to protect two lambs than it is to protect one. However, the following practices have been successful in reducing losses.

  1. Producers fortunate enough to be in areas where the fox baiting activities by groups of producers were synchronized, have reported improved survival rates.
  2. Bait the twin lambing paddocks more heavily.
  3. If possible, surround the twin lambing paddocks with paddocks where the singles are lambed.
  4. The use of guard animals is known to be successful in improved survival rates