Putting BLUP into context

Red Angus stud producer Dirk Giliomee in ­Bredasdorp, ­Western Cape, explains that BLUP is a useful breeding concept, but it should be used with caution, taking care not to neglect other methods, such as ­performance testing and weight records. Glenneis Erasmus reports.
Issue date 1 June 2007

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The introduction of best linear unbiased prediction (BLUP) is helping producers to make better, more informed ­breeding ­decisions than ever before. BLUP is a ­statistical programme that uses all the available information on all recorded ­relatives, ranging from an animal’s parents and progeny to cousins, aunts, brothers and sisters, to calculate the estimated ­breeding values (EBVs) for the specific animal. According to an article that appeared in the British magazine Beef and Sheep in 2001, BLUP has doubled the rate of genetic progress in leading beef breeds in the UK.
Today, the use of BLUP has also become the foundation of the selection strategies of many top breeders in South Africa.

BLUP plus common sense

Dirk Giliomee, owner of the Red Angus stud on his farm Prinsvlei, ­Bredasdorp, says BLUP is a useful tool when ­selecting animals for breeding purposes, but warns that it should not be used at the expense of good common sense.
“EBV can give a good indication of how an animal is supposed to produce or what the offspring should look like. But these values remain estimates and are not always 100% accurate. Farmers should still make use of ­performance testing and weight records, while considering the suitability of the targeted animal in their production environment,” Dirk says.

Putting BLUP to the test

Dirk uses one of his cows, Prinsvlei Deluxe that was born in 1996, as an example. ­Prinsvlei Deluxe has been one of his top breeders even though she had a birth weight of 47kg. BLUP ­estimated the birth weight of her offspring at plus 5, which is totally undesirable. Most producers were ­unwilling to buy the offspring of this cow.
The cow’s birth weight EBV completely discounts the fact that she was born ­during a year when there was an abundance of pasture. She is one of Dirk’s best animals and her offspring, in contrast to BLUP predictions, have never weighed more than 37kg, which is quite acceptable. Dirk’s animals produce calves at a birth weight of around 38kg in June, when feed is scarcer in the months prior to birth, while an average birth weight of 43kg is attained in August when there is a large amount of feed available.

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Manipulating birth weight

Dirk actually makes use of this factor to manipulate the breeding weights of ­cattle on his farm. Heifers, for example, are ­inseminated to calve around March or April. These calves have a birth weight of 32kg. The rest of the herd is inseminated to calve four months later. The weights of these calves are about 7kg heavier than those of the heifers. This illustrates that it is not only the bull’s fault that the birth weight of an animal is high. “If I want my cattle to ­comply with the ideal BLUP values for birth weight, I would either have to ensure that cows produce calves during times when there is a shortage of feed, or I would have to put my cows on a diet to ensure they produce small calves,” Dirk says. He acknowledges that birth weight should not be excessive, as this could lead to birth complications. However, he believes that birth weights that are higher than the ­proposed BLUP values, would still be suitable for his production conditions.

Production environment

“Farmers have to select animals that are ­suitable for their production area. They will have to choose a size animal that would yield the highest return with the carry ­capacity and feed availability of their ­specific ­production conditions. Small Angus beef cattle might be more desirable in Natal than in the Western Cape, due to the differences in pasture,” he explains. BLUP ­provides a measure known as the feed conversion ratio, which expresses animal production in kilograms per hectare. In other words, it reflects the amount of feed the animal would have to eat to gain 1kg in weight.

Low breeding weights

Dirk adds that producers should not get side-tracked by the suggested low ­breeding weights of BLUP and that ­breeding weight should be seen in ­context. “This focus on low breeding weights can result in the breeding of cows that have small pelvic opening, which could also cause birth-related problems,” he warns.
Dirk says that there’s also an ­advantage to ­breeding animals with higher birth weights, as they grow faster. Recorded Angus BLUP values ­confirm that ­animals with ­negative birth weight EBVs, seen as a ­desirable trait, often have ­unacceptably low EBV growth rates. This should be ­considered before ­breeding material is selected, since the ­ability to grow an animal as fast and with as few inputs as possible to a ­­­­market-ready size, is one of the main ­drivers of ­profitability for any beef producer.

Marbling, the small white flecks of fat found inside meat, has rendered Angus beef superior to others in terms of ­juiciness and ­flavour. Good news is that this higher ­degree of marbling in Angus does not increase cholesterol and only slightly increases saturated fats. The higher quality of this meat is ­acknowledged in ­England, Japan, Australia and America. Quite a few South African restaurants and butcheries sell only Angus beef, says Dirk Giliomee. He says that the industry has been ­trying to establish Angus beef as a brand for the past 15 years, as there is a group of ­consumers that are willing to pay ­premiums for this meat in South Africa. The effort to date has been curbed by some of the role-players in the marketing chain.

Australia has managed to significantly increase Angus beef consumption over the past five years. SA Angus breed director, John Boulle, has therefore ­approached Michael Pointer, CEO of Angus ­Australia, to provide our producers with advice on ways to feed, slaughter and ­promote Angus beef on a regional basis. Pointer is expected to come to the Western Cape during the last week of July to provide all role-players in the Angus industry, from producers, feedlot owners, meat processors to ­distributors, with advice and information.

The Western and Southern Cape Angus club will also have a production auction on 27 June at Paarl ­Agricultural High School. For more ­information on both these events contact SA ­Angus Society on (051) 447 9849.

Contact Dirk Giliomee on 083 302 5575. |fw