Sally and I started the Dulverton herd in 1981, my how those 24 years have flown. During the mid eighties we both became convinced that it was just as important to focus on the carcase traits as it was the on-farm traits, eg fertility, calving ease, growth, temperament. Why? Quite simply because “People Eat Meat”. That’s it -they don’t eat fertility, they don’t eat calving ease, growth or temperament, they eat beef from the carcase. O.K, if we can accept that people eat meat then we might well ask what are the attributes that these people look for in the product?
It just so happens that I did spend eleven years (1991-2002) working in projects that attempted to define eating quality as perceived by the consumer of beef. These projects culminated in the development of the MSA (Meat Standards Australia) beef grading system. One of the outcomes from the consumer work was a definitive statement re their (the consumers) wish list for beef:-
- i.) It must satisfy expectations for eating quality. These traits include Tenderness – particularly for the “everyday” eating experience but also Juiciness and Flavour. Juiciness and Flavour reserve a higher priority for the special occasion eating.
- ii.) It must be Price Competitive. Price competitiveness is a topic that can consume volumes. However, suffice is to say, that because beef is the preferred protein source of our consumer (68% of males prefer it, 49% of females prefer it) it doesn’t have to be the cheapest, particularly for ‘special occasion’ eating. Price is none the less a major consideration of intending purchasers.
- iii.) It must be more convenient and offer variety. Time in preparation being a major stumbling block e.g. Stir Fry versus Casserole, Grill versus Roasts etc.
People eat beef and they expect it to fulfil a few basic requirements, so what’s this got to do with breeding beef bulls? Quite simply it reinforces the need for beef producers to focus on carcase traits as well as the all-important on farm traits.
What are the carcase traits of importance:-
- i.) Weight for age. This is because growth rate impacts on tenderness. In addition, the more consistent the daily gain over whole of life the more even the fat distribution. An even cover of 3mm over the important primals is essential to prevent ‘toughening of muscle fibres’ due to cold shortening. Excess fat results in reduced saleable yield which impacts on price competitiveness – optimum fat.
- ii.) Marbling. Marbling %, not IMF, is the trait that best describes intra-muscular fat. Marbling is the fine flecks of fat that are evenly distributed through the muscles, in the ‘spaces’ between muscle bundles. IMF% is the total fat measured within the boundary of the muscles. The distinction is extremely important particularly domestically where consumers preference for intramuscular fat is between 3.0 and 5.5%. The more even the distribution the greater the opportunity for the consumer ingesting a small portion of fat with each mouthful. The finer the fleck the less the ultimate fat intake. Remember it’s the fat that contributes the most to the unique beef flavour. Further some fat with each mouthful ensures the salivary gland is being stimulated to produce saliva during chewing. This means the juiciness sensation is enhanced. IMF% on the other hand simply means the total amount of fat so it can often occur as big blobs in the muscle. As a result of the uneven distribution the consumer often gets mouthfuls with no fat and then a mouthful with the big blob and the ‘furry’ taste sensation of excessive fat is a negative. The ‘dry’ sensation is also a negative, that is, not juicy.
- iii.) Saleable Yield or Retail Beef Yield (RBY). RBY is of course a function of Growth and more importantly the composition of that growth, bone, muscle, fat being the three tissues of relevance. Given that its not our goal to sell bone for consumers to eat the relevant tissues are muscle and fat. Dr. Rex Butterfield once described the preferred carcass as being the one with minimum bone, maximum muscle and optimum fat. Unfortunately the Minimum and Maximum words can become dangerous, people will attempt to push to limits. However, it is the general direction that Butterfield provides that is important. Lets get as much muscle into the equation without distorting the other ‘bodily functions, at preferred fat levels to help ensure the all important consumer requirements for price competitiveness. That is, the consumer preference is for fat at the level of about 5%, the balance needs to be muscle. Excess fat increases costs. Fat is more costly to produce (about 2 ¼ times more costly than muscle) and the excess has to be trimmed which is of course another cost burden. It’s not uncommon to see differences in excess of $150 per 350kg carcase in the saleable yield outcomes. We must aim for the taste fat (marbling) and not excesses of the waste fat (subcutaneous fat).
So to satisfy the consumers’ expectations for Eating Quality (Tenderness, Juiciness and Flavour) we must address the issues of growth and marbling. To fulfil the requirement for price competitiveness, address the issue of growth and retail beef yield. Convenience is more an issue for the value add and packaging segments of the processing and further processing sector.
How is it possible to select for Retail Beef Yield and Marbling in the one animal at the one time? Surely because marbling is “a form of fat” and retail beef yield implies selecting against fat, we have an impossible task on our hands. Not so!
It is possible to select for positive muscling, positive marbling and negative/reduced fat. We have been doing this since the late 1980’s. There are bulls capable of fulfilling this requirement, it will be made easier though, if we were to conduct more properly constructed progeny tests. The identification of the combination of marbling genes and the Retail Beef Yield genes, by organisations such as Genetic Solutions and the CRC Mark III will take much of the confusion out of this dilemma. That is, attempting to select for in the one animal positive muscling, positive marbling and negative/reduced fat, they appear antagonistic but they don’t have to be.
Selection for negative fat, positive muscle and positive marbling isn’t easy, that is O.K., cattle breeding isn’t easy. It’s obvious many will be asking “Isn’t this negative fat selection going to lead to hard doing cattle with lower fertility rates?” Maybe. However, take time to think about this issue for awhile. Remember fifteen to twenty years ago Angus cattle were recognized for their early maturity so to select for a reduction in total subcutaneous fatness, was to identify the faster growing later maturing cattle essential to fulfil the requirements of the 400kg carcase. It is important to keep a watchful eye on maturity pattern because cattle do tend to become smaller and therefore more early maturing if pressure isn’t maintained on the negative fat trait. It is possible to maintain pressure on maturity pattern and still have the female herd fulfil functionality. Stephen Collins, who prior to venturing into Glenwarrah Herefords, had one of the most productive Australian Illawarra Shorthorn herds in NSW. Stephen taught me the importance of selecting ‘milkers’ with constitution and capacity, these were the cows that could produce plenty of milk, not put fat on their backs and settle in calf within 3 months of them having calved. What is constitution? Put simply, heart girth, width of chest floor, that is, room for the essential organs (heart lung rumen). What is Capacity? Spring of rib, depth of body and width of body. These are the traits that the cow man over time can build into the herd that result in do-ability (the ability to survive and function at lower levels of sub-cutaneous fat). While selecting for negative fatness on the one hand we can also select for on-farm functionality (fertility, milking ability, survival etc) by putting pressure on constitution and capacity. It isn’t necessary to have females that “carry the haystack on their back” in the beef herd if pressure is brought to bear on constitution and capacity.
It is extremely difficult to understand how B3 indexes can be used as a genetic selection tool when the first component of the shorthand description is not even included in the calculation. The alpha notation in this case the ‘B’ represents the Yield component, the numeric in this case the ‘3’ the eating quality (texture, marbling etc). It is interesting that indexes of in excess of $100 can be printed for certain bulls yet these bulls have RBY% of -2.2 bottom 1% of the breed. Yet again this points to the fact that not all of the important profit driving traits are being included in enough breeding programmes. Saleable Retail Yield is hugely important it cannot be ignored.
Hopefully this outline has provided an insight into the issues that confront our industry. We shall maintain our vigilance on following through with continuing to strive to include the on-farm traits (fertility, calving ease, maternal, growth, temperament etc with the all important traits of eating quality and saleable yield. These last two droughts have strengthened if anything our resolve to get the lean growth (saleable yield ) and eating quality traits right. This is because the Feedlots have been instrumental in holding up prices for feeder cattle even though commodities such as grain and roughage have been extra ordinarily high. Remember previous droughts when prices for unfinished (feeder type cattle) have plummeted.
Putting it all together is our challenge, we can no longer chase single trait selection fads, we must go forward with the three groups of traits on our radar:-
- On-farm (Fertility, Calving ease, Growth, Temperament)
- Eating quality (Marbling, Tenderness)
- Saleable yield (Muscling reduced fat growth)
Happy Breeding
Greg Chappell
