Muscling myths demolished by new research
From the February 2009 edition of Agriculture Today.
Groundbreaking research has smashed the perceived myths associated with increasing muscling in cows.
Beef producers have commonly believed that as you increase the muscling in beef cattle females you will have a negative impact on overall cow herd productivity.
This includes factors such as female fertility, calving ease, calf survival, cow milk production, cow survival (longevity) and progeny growth rate.
These beliefs have been put to the test in the cattle herd at Glen Innes agricultural research and advisory station and recent results are proving contrary to common perceptions.
In fact, early indications are that not selecting for muscling in beef females is detrimental to whole herd productivity and profit.
Glen Innes has been home to some 300 cows which have been carefully selected and bred over the past 16 years to create the most divergent muscling herd within Australia.
The cow herd currently consists of a "low" muscle line with muscle score D or worse, a "high" muscle line (muscle score C+ or better) and a unique myostatin line (muscle score B).
The myostatin line carry the myostatin gene responsible for superior muscle development commonly seen in Double Muscled breeds.
However, through DNA identification, researchers at Glen Innes have been able to identify and breed with animals containing only one copy of the myostatin gene, hence eliminating the negative effects of double muscling.
These animals offer superior advantages in increased muscle mass, an increase in rib eye area and a small reduction in fat which, combined, contributes to a greater retail meat yield.
Results for other cow productivity traits show no difference between the muscling selection lines.
Yearling and slaughter growth rates of progeny are very similar, as are calf weaning weights, indicating cow milk production is similar.
There was no difference in calving ease using heavy muscled bulls or in heavy muscled cows (even when high muscled bulls were used on high muscled heifers), and calf survival for all three selection lines was the same.
There has been no difference in female fertility, with PTIC percentages being very similar, and cow survival after 16 years of selection has also shown no difference.
It is estimated that a one per cent increase in meat yield would be worth more than $20 million annually to the beef industry in NSW alone.
It comes as no surprise that some major processors are looking to move toward a more valued base payment system, whereby producers will be rewarded for higher yielding animals or more heavily muscled animals.
Muscularity is but one of only a number of traits to take into consideration when selecting breeding animals.
Research such as this project at Glen Innes is vital in determining the effects some breeding and management decisions may have on the long-term productivity of the cow herd.
Cow herd productivity
| Number of cows mated since 1998) 1521 cows |
Calving percentage | Weaning percentage | |
|---|---|---|---|
| High Muscle Group | 735 | 85.7 | 82.6 |
| Low Muscle Group | 708 | 83.9 | 80.9 |
| Myostatin Cows | 78 | 87.2 | 83.3 |
Results from Glen Innes in terms of calving and weaning percentage since 1998.
Contact Matthew McKiernan, Glen Innes, (02) 6730 1941, matt.mckiernan@dpi.nsw.gov.au
