4
68 farmer’s weekly 4 DECEMBER 2020 T he most dominant roundworm in South Africa’s summer rainfall areas is Haemonchus contortus. Known as wireworm (haarwurm) in South Africa and barber’s pole worm elsewhere, it is a blood-sucking parasite that targets sheep and goats, and can cause substantial blood loss in affected animals. It is particularly rife from February to May. According to Nico Grobler, who keeps a 300-head Meatmaster flock near Ventersdorp in North West, wireworm can seriously threaten the long-term sustainability of a sheep flock and is the greatest hazard to sheep farming in his area. “My objective is eventually to eradicate all animals in the flock that need treatment for wireworm. To that effect, I only use rams that have never been dosed for wireworm,” he says. Grobler and his team use the FAMACHA system to evaluate the animal’s anaemia level and thereby the extent of wireworm infestation and whether or not treatment is required. This is done by comparing the colour of the mucus membrane on the sheep’s lower inner eyelid with the colours on a standardised ‘eye score’ card. TO CULL OR NOT TO CULL? Very few of the ewes that need to be treated for the parasite are allowed to remain in Grobler’s flock, while rams needing treatment are culled without exception. The ewes are weighed and monitored monthly according to the FAMACHA system. The decision of whether or not to cull is based on the infected animal’s genetic merit and the value of the contribution she makes to the stud. A variety of products are used to treat infected animals to prevent the development of resistance. Grobler says he simply cannot afford any animal that threatens the health status of the flock. “I replace 20% of the ewes annually. By continually replacing them with wireworm-resistant animals, I’m well on the way to having a flock that’s entirely unaffected by the parasite. So far this year, I’ve had to treat only about 20% of the adult ewes, despite the extremely high rainfall of 800mm.” To illustrate the value of rigorous selection for resistance, Grobler says that 80% of the progeny of a particular ram that was dosed once contracted wireworm in 2019, although the ram fared exceptionally well in veld tests. However, only 20% of the progeny of a ram that was never dosed were affected by the parasite in 2019. RESISTANT INDIGENOUS BREED The Meatmaster is a composite sheep breed developed in South Africa from a number of breeds, including the indigenous Damara. It has natural genetic resistance to parasites, making it a particularly desirable breed in this environment; it resists endoparasites, including gastrointestinal Through rigorous selection, Meatmaster stud breeder Nico Grobler from North West has succeeded in significantly reducing wireworm infestation in his Kern Meatmaster flock. This has enabled him to run the stud successfully in an area highly susceptible to the parasite. Annelie Coleman reports. Breeding wireworm- resistant Meatmasters LIVESTOCK Meatmaster Fast Facts Wireworm poses the greatest threat to sheep farming in Ventersdorp and surrounding districts. Stud breeder Nico Grobler aims to develop a wireworm-free Meatmaster flock over the next five years. Only rams that have never been dosed against wireworm are used in the Kern Meatmaster flock. NICO GROBLER SUPPLIED

Breeding wireworm- resistant Meatmasters · 2020. 12. 8. · Wellington Paarl Durbanville Bellville Stellenbosch Somerset West Grabouw Kleinmond Vermont Hermanus Gansbaai Franschhoek

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Page 1: Breeding wireworm- resistant Meatmasters · 2020. 12. 8. · Wellington Paarl Durbanville Bellville Stellenbosch Somerset West Grabouw Kleinmond Vermont Hermanus Gansbaai Franschhoek

68 farmer’sweekly 4 DECEMBER 2020

The most dominant roundworm in South Africa’s summer rainfall areas is Haemonchus contortus. Known as wireworm

(haarwurm) in South Africa and barber’s pole worm elsewhere, it is a blood-sucking parasite that targets sheep and goats, and can cause substantial blood loss in affected animals. It is particularly rife from February to May.

According to Nico Grobler, who keeps a 300- head Meatmaster flock near Ventersdorp in North West, wireworm can seriously threaten the long-term sustainability of a sheep flock and is the greatest hazard to sheep farming in his area.

“My objective is eventually to eradicate all animals in the flock that need treatment for wireworm. To that effect, I only use rams that have never been dosed for wireworm,” he says.

Grobler and his team use the FAMACHA system to evaluate the animal’s anaemia level and thereby the extent of wireworm infestation and whether or not treatment is required. This is done by comparing the colour of the mucus membrane on the sheep’s lower inner eyelid with the colours on a standardised ‘eye score’ card.

TO CULL OR NOT TO CULL?Very few of the ewes that need to be treated for the parasite are allowed to remain in Grobler’s flock, while rams needing treatment are culled without exception. The ewes are weighed and monitored monthly according to the FAMACHA system. The decision of whether or not to cull is based on the infected animal’s genetic merit and the value of the contribution she makes to the stud.

A variety of products are used to treat infected animals to prevent the development of resistance.

Grobler says he simply cannot afford any animal that threatens the health status of the flock.

“I replace 20% of the ewes annually. By continually replacing them with wireworm-resistant animals, I’m well on the way to having a flock that’s entirely unaffected by the parasite. So far this year, I’ve had to treat only about 20% of the adult ewes, despite the extremely high rainfall of 800mm.”

To illustrate the value of rigorous selection for resistance, Grobler says that 80% of the progeny of a particular ram that was dosed once contracted wireworm in 2019, although the ram fared exceptionally well in veld tests. However, only 20% of the progeny of a ram that was never dosed were affected by the parasite in 2019.

RESISTANT INDIGENOUS BREEDThe Meatmaster is a composite sheep breed developed in South Africa from a number of breeds, including the indigenous Damara. It has natural genetic resistance to parasites, making it a particularly desirable breed in this environment; it resists endoparasites, including gastrointestinal

Through rigorous selection, Meatmaster stud breeder Nico Grobler from North West has succeeded in significantly

reducing wireworm infestation in his Kern Meatmaster flock. This has enabled him to run the stud successfully in an area

highly susceptible to the parasite. Annelie Coleman reports.

Breeding wireworm-

resistant Meatmasters

LIVESTOCK Meatmaster

Fast FactsWireworm poses the greatest threat to sheep farming in Ventersdorp and surrounding districts.

Stud breeder Nico Grobler aims to develop a wireworm-free Meatmaster flock over the next five years.

Only rams that have never been dosed against wireworm are used in the Kern Meatmaster flock.

NICO GROBLER

SUPP

LIED

Page 2: Breeding wireworm- resistant Meatmasters · 2020. 12. 8. · Wellington Paarl Durbanville Bellville Stellenbosch Somerset West Grabouw Kleinmond Vermont Hermanus Gansbaai Franschhoek

ABOVE:Kern Meatmasters are known for even fat distribution and good body length and depth, and are sought after in the private slaughter market, where the carcasses earn a premium.

LEFT:Although his stud is run in an area where wireworm is endemic, Nico Grobler had to treat only 20% of the ewes against the parasite in 2020, despite the very high rainfall at the beginning of the year.PHOTOS: NICO GROBLER

4 DECEMBER 2020 farmer’sweekly 69

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Paternoster

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Wupperthal

Citrusdal

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Bokhara

Rooiputs

Vaalputs

Garies

Kamieskroon

Springbok

Steinkopf

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Pofadder

Kleinsee

Port Nolloth

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Walvisbaai

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Windhoek

Otjiwarongo

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Brandvlei

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Upington

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Twee Rivieren

Bokspits

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Morebeng

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Louis Trichardt

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Musina

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Phalaborwa

Vaalwater

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Page 3: Breeding wireworm- resistant Meatmasters · 2020. 12. 8. · Wellington Paarl Durbanville Bellville Stellenbosch Somerset West Grabouw Kleinmond Vermont Hermanus Gansbaai Franschhoek

70 farmer’sweekly 4 DECEMBER 2020

ABOVE:The ideal Kern Meatmaster

ewe is femine and highly fertile, with a well-

defined Roman nose that indicates the Damara

bloodline in the sheep.

OPPOSITE PAGE, FROM TOP:

Nico Grobler says it is important to retain as many of the indigenous bloodlines

as possible, as these underpin the functionality

and adaptability of the Meatmaster breed.

Grobler and his wife Marize breed yard chickens as

part of their farming concern. The breed is

being developed along the lines of the indigeneous

Venda chicken.

Sheepdog crosses are valuable partners in the

fight against predation. The dogs are put with the sheep shortly after weaning, and remain there permanently.

LIVESTOCK Meatmaster

parasites such as wireworm and tapeworm, as well as ectoparasites such as ticks and mosquitoes. The resistance of indigenous breeds to parasites and their ability to maintain reproductive efficiency under sometimes highly challenging conditions have developed over thousands of years.

GRAZINGThe Kern stud is kept on 200ha of leased sourveld. The grazing consists mainly of red grass (Themeda triandra), steekgras (Heteropogon contortus) and turpentine grass (Cymbopogon caesius). Bankrupt bush (Seriphium plumosum), a highly unpalatable encroacher, is also present, but Grobler says that the Meatmasters, being non-selective grazers, have almost eliminated the problem on the farm.

Conditions on the farm are tough. Between 2014 and 2018, rainfall never exceeded 300mm a year, while 550mm fell in 2019 and 800mm in 2020. The average temperatures fluctuate between below freezing in winter and the high 30s in summer.

Grobler, his father Klaas and mother Sonia started the Kern Stud in 2007, building the flock using the best available genetics from the outset. The objective was to breed veld-adapted, hardy, functional sheep that conformed to, and even exceeded, breed standards.

Exceptional growth, fertility and carcass quality set Kern Meatmasters apart. The animals are renowned for their even fat distribution and body length and depth, and their carcasses earn a considerable premium on the private slaughter market.

Grobler maintains an average annual weaning percentage exceeding 200% and an average weaning weight of between 33kg and 35kg.

BREEDING GOALSKern ewes are strong, hardy and feminine, with a functional, efficient body conformation and well-placed legs for excellent walking ability. Grobler selects for a well-balanced ewe, as this ensures optimal functionality.

The rams are balanced and masculine, with sturdy forequarters. They are strong and muscular, with a good balance between length, width and depth. Adequate breadth between the front legs is important, as well as strong hocks in both the front and rear legs. Grobler selects ruthlessly against anything that may impair agility and walking ability. The rams must be virile and have excellent servicing ability.

A strong and well-defined Roman nose is important, as this is a clear indication of Damara genetics. Grobler says it is vital to retain as many of the indigenous bloodlines as possible, because these underpin the well-known functionality and adaptability of the breed.

“Kern Meatmasters’ breeding objective is to breed money-making sheep that need as few production inputs as possible while still realising maximum income. The composite Meatmaster has from the onset been developed along economical lines,” he explains.

The Meatmaster has short, shiny hair with an underlying blanket of fluffy, fine wool.

Page 4: Breeding wireworm- resistant Meatmasters · 2020. 12. 8. · Wellington Paarl Durbanville Bellville Stellenbosch Somerset West Grabouw Kleinmond Vermont Hermanus Gansbaai Franschhoek

4 DECEMBER 2020 farmer’sweekly 71

One of Grober’s breeding objectives is to produce animals with dense coats for maximum isolation against climatic extremes and added protection against ectoparasites.

GUARD DOGSThe Meatmaster’s highly developed flocking instinct makes for easier mustering and management, especially under rugged and extensive farming conditions, and also increases protection against predators. In addition, Grobler has developed a number of ways to counter stock theft and predation, which are challenges that livestock farmers in the Ventersdorp area have to contend with.

He kraals the flock at sunset and lets it out again at 7.30am. He also makes use of sheepdog crosses that stay permanently with the animals as guard dogs. When the pup is six or seven weeks old, it is placed in a small kraal with five or six young ewes and left there for a month without any human interaction, enabling the dog and the ewes to bond. After a month, the dog and the ewes are moved to the flock, where the dog will stay for the rest of its life.

Grobler says he prefers sheepdog crosses, as purebred sheepdogs’ herding instinct is so strong that they interfere when he works with the sheep. He finds sheepdog-boerboel crosses particularly effective, especially against predators such as black-backed jackal and caracal.

According to him, the dogs are extremely protective. “They become part of the sheep family, so to speak. It’s very endearing to see the sheep and dogs interacting. There’s mutual acceptance and they show affection to one another.”

CHICKENSIndigenous chickens add another dimension to the farming concern. Grobler, his wife Marize and even their 17-month-old son, Hannes, are passionate about the brightly coloured chickens that scrurry around the homestead looking for food. His ultimate aim is to breed a no-fuss backyard chicken (werfhoender) along the lines of the Venda chicken. He says the chickens are highly effective at reducing populations of insect pests, expecially flies. Phone Nico Grobler on 071 681 1180, or email him at [email protected]. FW

The objective is to breed functional, hardy sheep that meet or exceed breed standards