Key Points:
EWES in good condition prior to joining will increase the probability of reproductive success. A concise joining period will also increase animal husbandry efficiencies and ensure maximum ram exposure. Check that ewes have the capacity to support lambs and cull ewes with udder deficiencies. Plan now to ensure low worm risk pastures are available for ewes and lambs next year.
Ovulation rate is related to the condition score of ewes at joining. The higher the condition score at joining increases the potential number of lambs and decreases the chance of dry ewes in the flock. Highest reproduction rates have been achieved when ewes are in condition score 3 plus at day 17 of joining (end of first cycle). An extra 20 lambs per 100 ewes joined can be achieved for one extra condition score at joining, though this advantage decreases once ewes exceed a condition score of 4 or above.
Merino ewes in poor condition (below condition score 2) will result in more than 20 per cent of ewes being dry. Maiden ewes must reach at least 85 per cent of their adult body weight prior to conception to increase chances of conceiving. The condition of ewes needs to be maintained over the joining period to ensure that optimum conception rates are achieved.
Joining duration is the length of time that the ewes are exposed to rams. Flocks that are to lamb during winter/spring should have a joining duration of five weeks or two cycles. An extended joining duration impacts on practices such as marking and weaning and decreases the effectiveness of pregnancy scanning. Increasing the length of joining duration, only results in less than 10% more ewes conceiving and producing 2-4 percent more lambs that will survive to 12 months of age.
Ewes should also be checked before joining to ensure that they are capable of feeding lambs. Ewes that do not have two teats should be culled. A major cause of twin loss is the inability of ewes to support both lambs through not having two teats.
Animal health issues need to be addressed with worms being the biggest risk factor over summer. Faecal eggs count tests should be conducted in mid December to indicate the level of infestation. Counts lower than 100 eggs per gram do not warrant drenching but should be monitored. Another test should be conducted at the end of February/March and drenching should be conducted if the count is greater than 80 eggs per gram. Paddocks need to be prioritised now for lambing and weaning to ensure low risk pastures are available at a time when ewes and lambs are most venerable to infestation.
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