Management of hinds around mating is mostly about ensuring that they are in good body condition and are provided a low-stress environment.
BCS and conception in adult hinds
Body Condition Score (BCS) is a very useful tool for farmers to manage adult hind nutrition. BCS has been shown to be intimately tied into both the timing of conceptions and the actual conception rate. In fact studies have shown that late conceptions and barrenness often go together, especially when associated with difficult summer and autumn feed conditions.
BCS is all-important, with the following effects from a drop in score:
- Drop from 4-3 - slight delay in conceptions and a few failures in old hinds
- Drop from 4 to 2.5 - 7-10 day delay in conception and 5-10% barren hinds
- Drop from 4 to 2 - 10-14 day delay in conception and up to 20% barren hinds
- Drop to 1.5 - catastrophic, general reproductive collapse.
This illustrates the importance of maintaining high BCS, or implementing improved nutrition to hinds e.g. supplementing with hay or concentrates in late lactation is not only an advantage in BCS gain, but is also proven to be cost-effective for both hind and calves, especially if BCS has been compromised by tough summer/autumn conditions. Such intervention needs to be started 3-4 weeks before the mating season starts. As a rule of thumb, for adult hinds an increase of BCS by 1 (e.g. from BCS of 2.5 to 3.5) will relate to a 10 kg increase in live weight.
Effects of weaning on conception
Lactation does not seem to exert a direct negative effect on conception date or on barrenness through ovulation failure. However, it can exert a major effect on BCS and, thus, indirectly influence reproductive success.
Pre-rut weaning allows hinds to ‘dry-off’ and subsequently re-direct their nutrients into regaining body mass before and during the mating season.
Recent studies have shown that for hinds that were either pre-rut or post-rut weaned on the same farms, the pre-rut weaned hinds were 7-12 days earlier to conceive. Differences in BCS accounted for this effect.
Reduce stress over mating
There is growing evidence that chronic (long-term, continued) stress on hinds over the mating period can delay conceptions by up to 10 days. Such stress may be caused by mixing of hind groups just prior to mating (social stress), repeated yarding or other factors such as continual disturbance by people and dogs.
Minimise stress on hinds over mating. Pre-rut weaning should be completed at least 2 weeks before mating to allow hinds time to settle down after the removal of their calves. Mixing of hind groups particularly hinds bought in from another farm should be done well before mating to minimise social stress by the time of mating.
Note: BCS of yearling hinds
Unfortunately BCS does not appear to be a particularly useful tool for the management of yearling hinds over mating. Young hinds tend to have very low body fat and tend to direct nutrients into lean body mass, thus, BCS, which largely monitors changes in superficial fat cover, does not change much in yearlings. However, their absolute body mass (live-weight) is an important factor in mating success (see Puberty in hinds) and maintaining a high level of nutrition over the mating season is just as important for yearlings as it is for adults.
Information about Best practice mating management is in a handy Deer Fact sheet. Download your own copy here >>
Asher, G.W., Pearse, A.J. (2002) Managing reproductive performance of farmed deer: the key to productivity. Proceedings of the Third World Deer Farming Congress, Austin, Texas, USA: 99-112.