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Wapiti Scoring Manual

for Young New Zealand Farmed Red Deer

                 

Jamie Ward AgResearch Invermay

 

The introgression of wapiti genes in to red deer has been shown to increase the live weight required for a yearling hind to attain puberty before her first mating at 16 months (Asher et al 2004).  This is believed to be having a negative impact on the yearling fertility for animals being managed as ‘red deer’.

If animals with >20% wapiti genes can be managed differently to their red deer cohorts they have a greater chance of meeting their true growth potential and achieving puberty threshold live weights and, hence, puberty. 

Click here for more on puberty threshold live weights

 

Animals with <20% wapiti genes can be essentially managed as red deer with no significant negative impacts on puberty, as they are most likely meeting their growth potential.

 

In 2004-05 we conducted a study to evaluate the possibility of a simple ‘Wapiti Scoring’ system for visual (phenotype) assessment of young animals; to allow selection of animals according to the amount of wapiti parentage in their genotype.

The study resulted in a useful scoring system which assesses certain wapiti phenotypic characteristics in individual animals and classifies them on a four point scale with 1 = no obvious wapiti features and 4 = obvious wapiti parentage.

The aim of this manual is to allow you to make assessments of your young animals, and to determine the level of wapiti introgression within your herd.  This will allow you to make informed decisions on management based on genotype.

 

Red, red, red, wapiti (WS 4) and red yearling hinds in summer pelage (click on images to enlarge)

 

Wapiti Scoring

 

For making the best visual assessments the following criteria should are important:

 

                 

Wapiti scoring animals in winter pelage; note colour differences in fluorescent light

 

In addition consideration should also be given to maturity and any known wapiti parentage (if records exist).

As you are breaking down groups into smaller pens, note individuals that stand out due to their stature and/or size as these characteristics become less obvious in smaller groups/pens.  In small groups, head and neck characteristics are the most obvious features.  Rump patch differences can be deceptive in yards (note size of rump patches in WS=1 animals above) and are generally most obvious in paddocks.

 

Wapiti Scores

We found that the best scoring method is for the scorer to make a subjective assessment based on the following four scoring categories, taking in to account a variety of phenotypic characteristics (rather than use any sort of quantitative assessment):

  1. No obvious wapiti features
  2. Some obvious wapiti characteristics
  3. Distinct wapiti features
  4. Obvious wapiti parentage

 

The scoring should be fairly intuitive.  When scoring animals you are best to go with your first instinct; once you get the hang of it, if you have to think too hard about your score for too many animals, then you probably aren’t doing it right.

 

Wapiti scoring process

 

Wapiti and red deer characteristics at the two different scoring periods

 

Red vs. Wapiti weaners in winter pelage

 

Red (Wapiti Score=1)                           Wapiti (Wapiti Score=4)

 

Stature

Finer, shorter more proportionate body and limbs

Tall, thicker, blockier, more rectangular body  Legs appear more gangly and awkward; less proportionate to body

 

        

Colour

Red and grey mostly.  Grey face and underside, red body

 

Legs same colour as underside

Chocolate-black and cream.  Head and neck (throat mane) darker, body lighter brownish grey to cream or straw coloured

Legs same colour as body

 

           

Head

More elongated muzzle, grey face, and red to brown chevron (forehead)

Pointed ears

Muzzle more stout/shorter, brown face and chevron (forehead)

Rounded fuzzy ears

 

      

Rump

Smaller, less obvious rump patch; any colour from red to white, often red top and white bottom.

Tail different colour

Shaped like an upside down pear

Large obvious creamy-white rump patch.

 

Tail same colour as rump

Heart shaped and  quite rounded looking

 

            

 

Click here for A4 printable version             Click here for A3 printable version

 

 

Red vs. Wapiti yearling hinds in summer pelage

 

Red (Wapiti Score=1)                           Wapiti (Wapiti Score=4)

 

Stature

Finer, shorter, more proportionate body and limbs

Tall, thicker, blockier, more rectangular body, deeper chest

Legs appear longer and less proportionate to body

 

         

Colour

Red and grey mostly

Red-flecked chevron (forehead), grey; face, muzzle, neck front and underside, red-flecked body

Colour lightens from back to belly

 

Legs same colour as underside

Rusty red, brown and cream

Head red and brown, neck and/or throat mane brown; darker than body

 

Body quite uniform rust red, underside mostly cream

Legs same colour as body

 

        

Head

Grey face, red to brown chevron (forehead)

 

Longer, skinnier ears

Rusty red-brown face and chevron (forehead), nose and muzzle dark brown

Shorter, wider ears

 

             

Rump

Smaller, less apparent rump patch, any colour from red to fully white, often red top and white bottom

Tail different colour

Less apparent viewed from side on

Larger, creamy white rump patch

 

Tail same colour as rump

Obvious viewed from side on

 

            

 

          Click here for A4 printable version             Click here for A3 printable version

                  

 

Calibrating your Wapiti Scoring

You may wish to utilise the GenomnzTM DNA testing tool the GenometerTM G3 Hybrid Test (or Elkmeter); to either calibrate your scoring or to check the genotype of individuals.  To do this, contact GenomnzTM and request sampling envelopes and instructions. 

If you wish to calibrate your scoring take samples from a selection of animals each score (of interest).  The GenometerTM Expected Elk % can then be plotted against Wapiti Score to assess how well your scores align with actual wapiti parentage.

Morphometric measurements were not found to be particularly useful predictors of genotype in young deer and are of very little use for calibration of scores.  Previous studies at 18-20 month old hinds found shoulder height and back length to be useful predictors, but this did not hold for younger animals.

 

Six month old wapiti (WS 4) weaners in winter pelage

 

Accuracy

This is a subjective process and you can expect different people to score differently; which is why we suggest you may want to calibrate your scoring. 

In our study we used two independent scorers who were not ‘calibrated’ as such, but each achieved good agreement with the DNA test results.  For all DNA tested females over all three scoring periods the mean (of both scorers) Expected Elk % of each wapiti score, were as follows:

 

To look at accuracy we considered false positives (scoring a ‘red deer’ as a wapiti) and false negatives (scoring a wapiti as a ‘red deer’) and a cut off point of 20% wapiti genes by DNA (>20% ‘wapiti’, <20% ‘red deer’).

 

Using Wapiti Score (WS) ≥1 to select ‘red deer’ females in winter pelage you would expect to include between 0 -10% of ‘wapiti’ and exclude up to 20% of ‘red deer’

Using WS ≥2 to select ‘red deer’ females in winter pelage you would expect to include between 27-36% of ‘wapiti and only exclude up to 4% ‘red deer

Using WS ≥3 to select females in winter pelage you would expect to include between 82-91% of ‘wapiti’ and exclude no red deer

 

If selecting wapiti; the accuracy figures can be reversed.   For example using WS ≥3 to select ‘wapiti’ females in winter pelage you would expect to include no red deer and 82%-91% of all ‘wapiti’.

 

From these results depending on how hard you want to select should determine your cut off point.  For example if you only want ‘red deer’ then select all animals scored WS 1, if selecting wapiti; keep all animals scored WS 3.  If you are selecting ‘red deer’ but want to be more conservative; keep all animals of WS 1 and 2.

When selecting males; the accuracy figures are not quite as good.

For more details on accuracy please refer to the table of accuracies in the full report.  Click here for full report

 

 

Acknowledgements

We thank Landcorp; especially Steve Mitchell and staff at Landcorp’s Hindon Station for providing access to the weaners, use of their yards and labour in the yards during this study and the Foundation for Research Science and Technology for co-funding this project.

 

Weaners in winter pelage, red (WS 1) (middle) flanked by wapiti (WS 4)