The tail-end ewe
Ewes weaned in good condition last year are likely give you more flexibility over the summer in terms of feed allowance and management. This will probably have a flow-on effect in terms of reproductive success this mating season, provided the ewes suffer no more than a gradual dietary restriction over the summer.
We know that using good conditioned ewes to tidy up rank summer pastures will have little effect on their oestrus and ovulation, unless their diet is restricted abruptly, or they are fasted e.g. in a drought situation. Prolonged under-feeding and emaciation (low body-condition) will suppress oestrus behaviour and ovulation, resulting in more dry ewes, and less multiples.
Given that so many of the production parameters for breeding ewes are linked to body- condition, it is logical to think that the productivity of tail-end ewes will be low. Apart from reduced fertility, tail-end ewes have a higher death rate, and appear to be more affected by worms indicated by higher faecal egg counts and dag scores.
Farmers have many approaches to dealing with tail-end ewes. These have ranged from ignoring them to culling, drenching and/or preferential feeding. Drenching light, daggy ewes in a mob may be useful but the benefits appear to be short-lived if ewes are not preferentially fed at the same time.
The adequacy of the feeding of your flock can be monitored using body-condition scoring. A hundred or so ewes can be scored at any yarding therefore giving you an indicator of how well the flock is progressing.
The incidence of tail-end ewes appears to be extremely variable from farm to farm, and season to season. However, in order to achieve high productivity, it appears more important that the average body-condition score (BCS) of a flock is 3 or above before mating, thereby minimising the number of ewes in BCS 2 or below before winter.
For further information on body-condition scoring ewes, contact your Totally Vets vet.
