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Grass fed, a whole new ballgame
South Africa - Grass fed cattle a whole new ball game from feed lots26 May 2009
Breeding cattle to thrive on veld means a total turnaround from breeding for the feedlot, and farmers can finish cattle for slaughter directly from the veld, contends Zimbabwean cattleman and animal scientist Johan Zietsman. It all depends on genetically programmed body condition, well-balanced hormone levels and the right type of bull. Annelie Coleman reports.
“cattle farmers have a simple choice,” says Zimbabwean cattleman and animal scientist Johan Zietsman. “Produce cattle that gain body condition naturally on veld, or artificially in the feedlot. But the genetics of the two types differ significantly.
“The main objective in cattle farming is to convert grass to meat and improve the veld where the animals are reared. Emphasis should be on higher productivity, lower costs and sustainability. Price isn’t as important.”
Johan stresses that stocking rate is the most important factor in determining profitability and return on capital. “To increase stocking rate and improve veld condition, eliminate selective grazing,” he urges. “Cattle must be able to utilise all available vegetation and be bred for a high relative intake to do well on veld. Current selection criteria ignore all this, leading to cattle that need ‘improved’ nutrition to stay productive.”
Thriving on veld
“The determining factors in breeding veld-adapted, productive cattle with the best possible body condition are a relatively small frame, climate adaptation, parasite and disease resistance and a large appetite,” says Johan.“It’s possible to achieve calving at two years with a high reconception rate by combining high relative growth and optimum body condition with a well-balanced hormone level. Without genetically programmed body condition, it’s impossible to finish cattle for slaughter at a young age on the veld.”“A veld-productive cow drops her first calf at age two and weans it at at least 50% of her own body weight, with little or no inputs other than enough grass and water. Veld-productive oxen will be ready for slaughter at an early age (milk tooth to two tooth) directly from the veld, or with minimum supplements under extreme conditions, including on sourveld.
Eating for body condition
“Everything in cattle production revolves around body condition, whether genetically programmed or out of a feedbag,” Johan continues. “Genetics are essential to breed veld-productive cattle that can deliver maximum profitability per hectare from conception to slaughter. While a large-framed animal’s total feed intake is greater than that of a smaller one, the relative intake is smaller, Johan explains. “The average 600kg cow eats 67% more than the average 300kg cow, but the intake relative to body weight is 20% lower, so the large animal’s body condition is lower.
“The swing to large-frame animals in the 1970s and the use of Phase D and C tests has damaged the industry. These animals are genetically handicapped as they require grass with a higher concentration of nutrients to attain the same condition as a smaller one on a relatively higher intake and non-selective grazing.
“There’s a negative correlation between size, absolute growth, feedlot feed conversion and body condition on the veld. “Fat meat requires more energy than lean meat, so leaner animals grow faster with a better feed conversion ratio. A fat animal loses less weight than a lean one when drawing on body reserves, since fat can contain three to four times the energy of lean meat tissue. “Long-haired animals get hotter in warm weather, inhibiting appetite and eventually body condition. Animals susceptible to parasite infestation and disease will also eat less. However, some animals naturally eat more, irrespective of other factors, and it makes sense to select big eaters, which will grow faster and put on more fat reserves.”
The essential ‘pony’ bull
Bulls have the greatest impact on the genetics of a herd and careful bull selection is vital, says Johan. “A farmer must ensure the bulls carry veld-productive attributes over to their progeny. That’s the only one type of bull that should be used – not ‘heifer bulls’ for small calves, ‘weaner bulls’ for milk, etc.” But the absolute growth values currently used focus on the opposite traits to those needed for veld productivity, and as a result the best bulls are often culled. “The right type of bull for producing veld-reared beef is the type that’s mostly discriminated against – short and stout with a tight skin,” says Johan. “These are indicators of a rapid relative growth rate. A bull with a tight skin can be likened to 7kg put into a 5kg container – a ‘pony’ bull.”
He explains that a bull that grows quickly relative to its full size will put on weight effectively and rapidly get fat. His heifers will reach sexual maturity sooner and his oxen will be ready for slaughter from the veld earlier, both characteristics influenced by body condition. “A successful bull’s fertility is determined by optimum body condition and a balanced hormone level,” says Johan. “Such a bull’s testes must be well-developed at 12 months, and he must appear masculine with a good meat-to-bone ratio. A strong herd instinct and mild temperament is important as well.
“The preferred bull’s dam must have calved early and regularly and weaned calves at at least 50% of her body weight.”
Success with the African genotype
Johan is convinced the indigenous African genotypes are most successful on the veld. “The two types available in South Africa are the Sanga and the Zebu. The Afrikaner, Nguni and Tuli are Sanga types while the Boran is a Zebu. But I feel the Afrikaner exhibits more Zebu characteristics because it has a larger hump over the shoulder than the Sanga type and a loose skin.” The Afrikaner has the fewest structural defects of all the cattle breeds in South Africa, he explains. “The breed’s ability to get fat is only surpassed by the Boran, while its meat-to-bone ratio is comparable to the Boran and the Tuli.
“The Afrikaner’s only, but very important, defect is a lack of fertility as measured against the age at first calving and consequent intercalving period. Breeding for the show ring and herd inspections has led to a hormonal imbalance in the breed, illustrated by some bulls with effeminate heads and some cows with big humps.”
This problem can be eradicated through strict selection, says Johan. “Some breeders are doing just that. All heifers must be put to bulls with strong, masculine heads and well-developed testes at the age of 14 to 15 months. Pony-type bulls must be selected based on their dams’ fertility, maturity at 12 months and a compact body type. Cows must have small humps and wean calves at 50% of their own body weight.”
“This type of Afrikaner can’t be selected in the show ring, through herd inspections or through Phase C and Phase D testing. BLUP breeding values are useless, as the selection process must be much simpler.” E-mail Johan Zietsman at firstname.lastname@example.org.
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