Management before lambing

LAMBING - THE CRUCIAL TEST OF MANAGEMENT

Lambing time is final result that is the culmination of all the management decisions that have preceded this event. Get it wrong pre lambing and you are locked into many days of disappointment and ultimately lower returns. So what can be done to ensure you maximse the number of lambs that make it through to sale?

The task of getting ewes (and rams) to the correct condition for joining is the first consideration to ensure good lambing percentages. While this can be largely dependent upon seasonal factors, there are some simple practices that can be carried out to ensure the best chance of higher conception rates. The ideal condition score for joining is around 3, not too fat/not too lean and this cannot be just an estimate from 200 paces out the window of the ute. You have to actually get the ewes yarded and assess them. Supplementary feeding with lupins just prior to joining will increase conception percentages by around 10-15%, the use of teasers will significantly condense lambing.; All measures that will prove advantageous at sale time. So you have a range of condition scores in the ewes and you have checked them for teeth and udders; It would now be useful to even up condition scores by dividing the ewes into two groups and adjusting feed requirements accordingly. This will depend on the extent to which condition scores vary but a range of between 2.5 to 3.5 is OK. If too fat (5) or too lean (1) some measures need to be taken to ensure good conception. Remember, cost of additional feeding at this stage will be repaid once lambs begin to hit the ground. If you are joining ewe lambs, they have to be at least 45Kg live weight and there seems to be some evidence that ewe lambs that have had a charmed life or have been overfed to this weight have reduced fertility due to “fatty udder” syndrome. There is also evidence of a maturity barrier for ewe lambs regardless of their live weight and delaying joining for a few weeks past when you consider them ready often yields rewards. The issue of joining ewe lambs is a whole new ball game and requires a little more fine tuning.

Ewes are ready to go and hopefully the rams have all been checked as fit and sound. The old saying that ‘fit and healthy rams are only 2% of your flock but unhealthy rams are you entire flock” is very true. Once again, some supplementary feeding of rams with lupins prior to joining is a good practice. While the percentage of rams to ewes varies depending upon preferences, 2% is a good safe average and rarely fails to produce good condensed lambing. There have been many reported situations over the past few years where low conception rates have been reported with causes ranging from over fat ewes, high mosquito populations causing infertility in rams through to extreme heat or prolonged periods of rain. Judgments allowing for these factors have to be made and unfortunately not all can be predicted. Ensure that all sheep management practices such as shearing, crutching and dipping are designed around lambing schedules so as not to interfere with ewes during critical times. Once the rams have been placed with the ewes, do not supplement with high protein feed. The jury is still out on this topic but there is evidence to suggest that high protein diets during joining reduces conception rates.

If all has been managed well, a 6 week joining should be sufficient, some evidence indicates that the gains to be made past a 5 week joining are insignificant. Managing ewe nutrition from the time the rams are taken out to lambing is crucial, perhaps not immediately but definitely in the last 6 weeks prior to lambing. To ensure good birth weights, especially in multiples, the additional requirements the unborn lamb(s) place on the ewe have to be accounted for in feed calculation. To attempt to ration feed requirements here will result in higher lamb mortalities (and ewe nutritional deficiencies) and consequently a reduction in live lambs to weaning. Scanning ewes after 40 days past the removal of the ram is a sure way to ensure that ewes carrying multiples are catered for and also gives an early warning if anything went wrong at conception. Not much joy if 3 weeks after lambing should begin, there is no sign of any lambs. If your scanning does not identify multiples, many would suggest you are wasting the time and cost of scanning as it will only allow possible sale of the dry's and an indication of how successful joining was. No management advantages come from just scanning wet/dry ewes.

Multiples have been identified, management practices put into place to account for feed requirements, so lambing should go according to plan. Obviously many things will affect the amount of interference required during lambing; the worst scenario is supplementary feeding during lambing which creates a new set of problems in relation to lamb mortality. Try to keep lambing mobs to around 150 -200 ewes as there is a train of thought that sheep can recognise no more than 150 individuals and mobs larger than this has been shown to increase mis-mothering and confusion amongst ewes resulting in higher lamb mortality. Recent research has indicated that lamb behavior at birth has a higher influence on lamb mortality than the maternal behavior of the ewe. I am not sure this applies to some Merino ewes I have seen be there is no doubt that healthier, more vigorous lambs will have a greater chance of survival than lambs that are slow to get going. Don't underestimate the affect of difficult births on lamb survival and evidence from the Sheep CRC suggests that over 50% of lamb mortality can be attributed to damage to the lamb's nervous system at birth. As a rule of thumb mortality in singles should not exceed 10%, or 20-25% in multiples. Obviously the more lambs you can get through to weaning, the higher the profit margin. While there will be reasons for some exceptions, producers should be aiming for weaning percentages above 100% and many producers are achieving numbers well above this figure.

More lambs to weaning results in more $$$$ in your bank account and greater profit margins.

 

There are a number of workshops and courses that producers can access to learn more about ewe management and maximizing returns from their sheep enterprise. Lifetime Ewe Management is a course designed to improve skills associated with ewe nutrition and pasture management. Go to the Sheep CRC website for more details.

Bred Well Fed Well is a free hands on one day workshop designed to provide information on breeding and feeding to improve profit margins.