Deer Growth Curves
Deer Growth Curves
Many deer farmers find it helpful to set targets for the growth rate of their finishing animals and replacement hinds. Monitoring growth rates against these targets lets them know if they are on track, or if a change is needed in the management of the animals. The Deer Growth Curves provide predictions of growth to hit liveweight targets for young deer. Printed posters are available as well as on-line calculators.
1. Venison Growth Target
Using real data from a large number of real farms the average growth curves for 'Spring Kill', and 'Summer Kill' venison animals are plotted month by month. These curves can be used to set targets for a desired kill profile, then monitor mob weights against the targets. To download a Printable copy of the Venison Growth Curve Poster click here>>
To link to the Venison Growth Calculator click here>>
Within the planner there are two standard curves: the black line targets a spring chilled season kill (based on growth rates from red stags); the red line targets a summer kill pattern (based on 80% of potential growth rates). Once drafting for slaughter starts, the curves take on a zig-zag shape. This is the consequence of removing the heaviest animals from the mob at each drafting, while still-growing animals remain in the mob between drafts.
The online calculator will predict kill weights and calculate gross income from venison sales based on a 1 September average mob weight. You can adjust drafting weights and anticipated venison schedule to allow comparison of different finishing options. For comparison, an indication of average performance for venison finishing targeting average kill date 7 November at an average live weight of 101 kg is also shown.
The calculator displays:
- Average draft date
- Calculated average gross income
- Average schedule
- Percentage of mob drafted before April 30
2. Replacement Hind Growth Target
Bodyweight has a huge impact on pregnancy rates for R2 hinds. R2 hinds have to reach target liveweights to enter puberty and start cycling. Well-grown R2 hinds are able to raise a fawn, but low reproduction rates in poorly-grown R2 hinds are a big lost opportunity for deer farmers.
For example, if MA hinds are 120kgs mature weight, R2 hinds of the same genetics need to hit 80kg to have a 50% chance of conceiving – this is called the “puberty thresh-hold”, and generally tends to be about 70% of mature body weight in most animals. However, in practice we want to achieve significantly better than 50% pregnant. In the case of a 120 kg MA hind genotype an individual R2 hind needs to be 100 kg to have a 95% chance of conceiving.
In reality we deal with mobs of R2 hinds, where some individuals are above the mob average (and have a slightly higher chance of conceiving) and some are below mob average (and have a significantly lower chance of conceiving). When we look across the whole mob, we can work out what the mob average needs to be to achieve an overall 95% conception rate – and in the example of a 120 kg MA hind genotype, the R2 mob needs to average 106 kg to meet this target.
The P2P programme has produced a guide to assist farmers monitor R2 hind weights and calculate probable pregnancy rates based on R2 hind mob average liveweights at time of stag joining. Farmers can use this to manage feed requirements for young hinds to achieve the target liveweight. This spreadsheet uses real data relating liveweight to pregnancy provided by AgResearch based on over 20,000 R2 hind records, and translates this to set targets based on mob average liveweight. This spreadsheet also allows mob average weights to be plotted on the predicted growth path needed to achieve pre-set pregnancy rates so that you can check to see that you are on track to achieve your target.
To download a Replacement Hind Growth Curve Poster - click here>>
To link to the Replacement Hind Conception Calculator click here>>
This resource has been produced as part of the PassiontoProfit programme, a Primary Growth Partnership co-funded by Deer Industry New Zealand and the Ministry for Primary Industries.