A Review of the New Zealand National Beef Competition in Comparison to the Australian Beef Carcass
Appraisal Method

Written by Lachlan James, Australian Murray Grey Society Youth Ambassador, 1998

Executive Summary

This study undertook a comparison of the New Zealand National Beef Competition with the Australian Beef Carcass Appraisal Method. A summary the main recommendations for the New Zealand Beef Carcass Competition is provided:

1. The points for dentition and carcass weight should be de-emphasised and replaced by more quality-related points.
2. Investigate the use of carcass ossification as an alternative criteria for estimating animal age.
3. Allocate points for a eye-muscle area adjusting for variation in carcass weight.
4. Make available extra points for carcass quality characteristics such as meat pH and fat colour.
5. Investigate the accuracy of prediction equations for estimating saleable meat yield from simple measures such as eye muscle area, fat depth and carcass weight as an alternative to current bone-out procedures.
6. Adopt a tenderness/taste evaluation for all carcasses, thereby enabling all entrants to be eligible for eating quality awards.

Introduction
The production of quality meat products that meet market specifications should be a major aim of cattle breeders and producers world-wide. To obtain benchmarks and comparisons between and within herds, direct comparisons of carcasses must be made. One method to obtain such comparisons is by the use of carcass competitions which can involve evaluation procedures that are more detailed and comprehensive than those used for carcass classification. Furthermore, carcass competitions help focus producer and breeder attention on criteria of importance to consumers.

To obtain useful information, the structure and scoring procedures of such competitions must aim to correctly rank carcasses on a combination of traits that reflect the current market situation and consumer requirements. The allocation of such points often differs widely between countries, due to market differences, and competition requirements.

This review of the New Zealand National Beef Competition aims to compare and contrast the judging criteria and point allocations used in New Zealand (NZ), with the Australian Beef Carcass Appraisal Method (Version 3.4). From these comparisons, objective recommendations and comments on the New Zealand competition were made.

Contrast Between New Zealand and Australian Competitions
Although both competitions endeavour to reward the most suitable beef carcasses that meet market requirements, the judging criteria and points allocation are very different. Within the NZ system, eye muscle area is a large determinant of carcass total points score.

Details of the scoring system used in the New Zealand and Australian beef carcass competitions are not provided in this document, however the relative distribution of points between the two competitions is outlined below in Table 1. It should be noted that the NZ percentiles are approximations based on a hypothetical steer entered in the carcass competition.

Table 1. Comparison of points allocation between New Zealand National Beef Competition (based on a hypothetical steer) and Australian Beef Carcass Appraisal Method 3.4.

As can be seen from Table 1, there is a larger emphasis placed on yielding attributes in the NZ system, compared to the Australian system. This may to some degree reflect differences in market requirements, however heavier carcasses with large eye muscle areas are disproportionately rewarded, compared with lighter weight or smaller eye-muscle area carcasses, irrespective of yield.

In general, bone-out aspects are not included in Australian carcass competitions, as opposed to the NZ system which enables the six highest scoring carcasses from each class to be boned out. Furthermore most Australian competitions that possess an evaluation of meat tenderness, do so as a separate arm of the competition, with all carcasses eligible for awards.

There are also differences in class weight divisions and requirements (i.e. bull class), however these are generally market orientated. One slight difference between competitions is that when large numbers of entries are received, in Australia, classes may be split into narrower weight ranges. At the majority of the Australian competitions, hoof judging is compulsory. On-hoof judging in New Zealand competitions has been discontinued in order to make the pre-slaughter holding period as short and as free of stress as possible.

Perceived Problems with the New Zealand System
There are some perceived problems that currently exist with the NZ National Beef Competition. Currently there seem to be excessive points allocated to eye muscle area, and carcass weight. This enables carcasses of larger eye-muscle area and carcass weight to potentially place high irrespective of carcass and meat quality. An example of such a situation is illustrated in Table 2, with two (hypothetical) carcasses competing in class 2, division 2 of the New Zealand Beef Carcass Competition.

Table 2. Comparison of two hypothetical carcasses competing in class 2, division 2 of the New Zealand National Beef Competition

Retail Beef Yield Percentage* 69.3 Retail Beef Yield Percentage* 69.9
*Retail beef calculated using equation from James (1997).
RBY% = 69.65 + 0.042 x EMA - 0.41 x 12/13th rib fat depth - 0.0016 x Liveweight.
Dressing percentage estimated at 55%.

Although this is an extreme case as, carcasses at the extreme of the target weight range have been chosen, it illustrates the current situation where larger carcasses, with larger eye-muscle areas are able to dominate the competition, despite having poor quality attributes, Assuming the prediction equation from James (1997) is an accurate estimator of retail beef yield (%) both of these carcasses had a similar estimated retail beef yield despite a 30 cm2 difference in eye muscle area.

Such carcasses are favoured because in order to be larger at a similar age it is likely that they will have grown faster, and one of the objectives of the competition is to reward faster growing cattle. This is a laudable aim but it may be that by attempting to reward both faster growth rates as well as superior carcass and meat quality characteristics in the same competition, neither job is done very well. The problem is that differences in carcass weight within a dentition class may not be a good indication of differences in growth rate because of the variation between individual cattle in the age at which various pairs of permanent incisors erupt. It may be preferable to accept that it is not feasible to reward for superior growth rate in a carcass competition and to focus instead on obtaining the best possible measures of carcass and meat quality characteristics.

The current bone-out procedure is likely achieving the stated objective of obtaining a measure of carcass yield. With the current bone out, the weight of specific muscles is expressed as a percentage of carcass side weight. However, the difference between animals in the proportion by weight of specific muscles does not vary significantly between animals of differing biological types. Current procedures are likely to be appropriate for separating high and low yielding carcasses but probably have poor predictive power for separating carcasses on the basis of their cuts distribution.

The present tenderness assessment procedure is only undertaken on the six carcasses from each competition that have scored highly in each class. The assessment of these carcasses for tenderness is thus a potentially biased sample, and may in fact not be assessing the carcasses that possess the highest consumer desired attributes. Given the current reliance on eye muscle area and weight, only carcasses that excel in those attributes are assessed for tenderness.

Conclusion/Summary
Carcass competitions are an avenue to achieve between and within-herd comparisons of economically important carcass and meat quality traits. However the judging criteria and points allocation of competitions must rank carcasses correctly, such that the most commercially acceptable animals/carcasses are rewarded.

For a copy of the full report, please contact either Mr. Paul Charteris or Professor Roger Purchas at Massey University, Private Bag 11222, Palmerston North