It requires stockmen on horseback to count or move the Bonsmara-type commercial beef cattle on Duminy Boerdery in KwaZulu-Natal’s Vryheid area.
This is because much of the 9 000ha property comprises 13 grazing camps ranging from 470ha to 840ha in size.
The farm’s mixed sweetveld/sourveld natural grazing is spread across hilly terrain, making it easy for the cattle in such large camps to spread out and become lost to the naked eye.
They therefore have to be sought out and found.
This system of large camps in which the cattle roam and graze as they desire has been used by the Duminy family, semi-retired father Boetman and his two sons, Jaco and Martiens, since 1998.
“I actually got the idea of using one-camp [continuous] grazing from my late uncle who’d been using it on his 500ha farm in our area since 1945. His entire farm was just one large grazing camp.
“And his cattle always had far fewer ticks, were sick less often, required less supplementary licks, and were generally in better condition than mine on the conventional rotational grazing system I was using at the time,” Boetman recalls.
Jaco and Martiens have continued to implement one-camp grazing, using it to produce approximately 500 long weaners annually for sale to feedlots and ox farmers via livestock auctions.
The brothers start selling weaners in May when the animals are seven months old and at a live weight of 220kg until they reach 15 or 16 months and a weight of 290kg at the end of the following February.
“The weaners are produced by our 1 200 breeding cows, which we put to about 75 bulls ranging in age from two-and-half to five years old,” explains Jaco.
“All our breeding females are own-bred, as are most of our bulls, but we buy in one or two bulls every year to bring fresh genetics into our herd.
“We sell our five-year-old bulls out of hand to other commercial beef producers.
“Our older cows and most of our non-selected heifers are sold at auctions in Vryheid.”
The origins of one-camp grazing
Expanding on his reasons for preferring continuous or one-camp grazing, Boetman says that in his earlier years of beef production, he had noticed that in small camps where beef cattle had been grazed, umtshiki grass (Eragrostis plana) tended to proliferate near the camp gates and around the lick troughs.
“For most of the year, the grass would grow tall and the cattle would walk through it without grazing it. But at the end of August and in early September, when the veld was at its poorest, just ahead of the coming spring rains and heat, the umtshiki would suddenly be grazed flat,” Boetman says.
He believes this is because umtshiki, being a pioneer grass, starts growing earlier than secondary, more palatable grass species on Duminy Boerdery.
Just before spring, the umtshiki becomes more attractive to the cattle.
Boetman was further convinced of his decision to implement one-camp grazing by an experience he had in the early 1970s.
In May, he had put a herd of 50 to 60 oxen into an 80ha grazing camp full of turpentine grass (Cymbopogon caesius) standing so tall that “it looked like a wheat land”.
“When I saw these oxen at the dip tank the following June, they were in good condition. In July I rode a horse to check on them and was amazed to see that their camp had been grazed so that it looked as if it had been mown. This got me thinking that God made all the grasses for animals to eat. It’s just that certain grasses are more attractive to cattle at certain times of the year.”
To make absolutely sure he was doing the right thing, Boetman compared cattle in a conventional rotational grazing system with those in a continuous grazing system.
He also sought advice from beef production experts from the then Stock Owners’ Organisation, and from discussions with Dr Jock Danckwerts of the Agricultural Research Council in the Eastern Cape.
According to Boetman, Danckwerts had been running trials on various grazing systems over 10 years. His conclusion was that light, but permanent, grazing was “by far the best” in terms of achieving optimal beef cattle production without causing degeneration of the veld.
Boetman, and now Jaco and Martiens, stock their camps at 1 MLU/3,5ha. The majority of their cattle comprise mature breeding cows, and these females are divided into herds each appropriately sized for a camp.
There are also five additional, separate camps for weaner heifers, castrated weaners, the 350 to 400 heifers that the Duminies have selected as replacement breeding stock, the 350 to 400 first-calvers, and the 75 bulls when they are not required for breeding.
Martiens explains that all the cattle on Duminy Boerdery do well on the mixture of thatch grass (Hyparrhenia hirta), umtshiki, red grass (Themeda triandra) and turpentine grass, which are all common in each of the 13 grazing camps.
The Duminies provide hay to the cattle in their on-farm feedlot, but production animals in the camps receive no feed.
The only supplements the animals receive are a phosphate lick during the warmer months of November to March, and a protein-based maintenance lick from April to September.
Heifers and first-calvers put to the bulls receive an added energy lick to promote conception.
Strategic use of cool fire
Fire is used as an important veld management tool on Duminy Boerdery.
“We always try to burn a third of each camp straight after the first spring rain every year on a rotational basis,” says Boetman. “This means that after three years, each camp has been burned in its entirety, and the cycle starts again.”
This reduces bush encroachment, which comes mainly from sicklebush (Dichrostachys cinerea), sweet thorn (Vachellia karroo) and paperbark thorn (Vachellia sieberiana).
The Duminies use a cool fire that runs with the wind; this burns encroaching bush, but not the roots of veld grasses, which causes permanent damage.While the cattle in each large camp can choose where to graze, they tend to favour the most recently burned section where older grass has been burned off and fresh growth stimulated.
Unfortunately, this new grass is high in moisture and low in fibre and can lead to diarrhoea.
“To minimise this, our cattle self-regulate by grazing some of the new grass, then grazing the unburned two-thirds of the camp, where they get fibre from the older grasses,” Boetman says.
According to Jaco, once the most recently burned third of the camp has been grazed, the cattle move of their own accord to the third of the camp that was burned the previous year.
Martiens adds that the animals seldom heavily graze the third of the camp that was burned two years ago.
“This allows this particular section of each camp to rest and go to seed before being burned and grazed the following year,” he says.
Surviving the drought
The Duminies agree that one-camp grazing was a saving grace for their beef enterprise during the recent three-year drought.
“Had we been using a multi-camp rotational grazing system during the drought, our agribusiness would have been in big trouble,” says Boetman.
“Each of our large camps has more than one water source in the form of springs and dams. When one water source in a camp dried up during the drought, the cattle in that camp could walk to another water source. This took a large management burden off our shoulders.”
Another reason the Duminies opted for one-camp grazing is because they had noticed that within two weeks of moving cattle into a new camp in a conventional rotational grazing system, a significant number invariably came down with redwater and gallsickness.
This does not happen regularly to the cattle on Duminy Boerdery because they have adapted to the conditions in which they spend most of their lives.
“Our extensive grazing system also means that we don’t have to provide hay to our breeding stock,” says Jaco.
“There’s enough grass throughout the year in each of our large camps.”
Phone Jaco Duminy on 083 983 1900, or email him at [email protected].
Phone Martiens Duminy on 083 299 1213, or email him at [email protected].