South African breed adapts to wetter climate
Dorper sheep were bred for the dry, arid conditions of South Africa but a Clutha Valley couple have successfully adapted the breed to the cooler, wetter conditions of South Otago, writes Rob Tipa.
Clutha Valley farmers Andrew and Kerry Lucas have spent 14 years selectively breeding white dorpers specifically for hogget mating on commercial sheep farms in the cool, wet climate of South Otago.
The success of their intensive breeding, selection and culling programme was rewarded at the 105th annual Mackenzie Highland A&P Show in Fairlie in April, when one of their ram lambs was selected as the champion dorper of the show and supreme champion meat breed overall, the first time this title has ever been won by a dorper.
Fairlie was the biggest display of dorpers to date in New Zealand with 10 breeders from the North Island to Invercargill exhibiting 105 sheep, an indication of increasing interest in the breed from commercial sheep farmers.
The breed was developed in South Africa in the 1930s from the dorset horn and persian breeds to handle arid conditions typical of continental Africa. It is also renowned for its year-round fertility, which means it is capable of lambing three times in two years.
Dorper is now the second-most popular sheep breed in Australia, largely because of its natural tendency to shed its wool, which eliminates the cost of shearing.
The breed was first imported into New Zealand from Australia in 2000. Breeders say dorpers are intelligent sheep, excellent mothers and are easy to work with. Naturally fertile, firstlambers generally produce a single lamb while twins and triplets are common in older ewes.
Lambs generally have a low birthweight but have exceptional growth rates and can reach 36 kilogram liveweight in three and a half to four months, with a carcass weight of 17-18kg, according to the New Zealand Sheep Breeders Association.
The breed is adaptable to any environment, largely due to its thick skin. Early imports from Australia did better on drier country, but the breed has adapted to cooler, wetter conditions as they have acclimatised to New Zealand.
They produce a lean, lightlymarbled meat with good flavour and no fat layer.
The breed is less prone to flystrike than other breeds because it has a naturally clean belly and rump and has a high tolerance of intestinal worms.
The attraction of the dorper breed for Andrew and Kerry Lucas was in finding a sheep breed that fitted in with their 1500 hectare mixed dairy, beef and sheep farming operation near Tuapeka Mouth in the Clutha Valley.
Moor Farm has been in Andrew’s family for five generations. It was originally part of the massive Greenfield estate, an early leasehold sheep run held by his ancestors that stretched from Greenfield to Lawrence until it was broken up for land settlement in the early 1900s.
The home farm, a mix of river silt and lighter alluvial soils with rocky outcrops, was converted to dairying in 2000.
Andrew and Kerry now have two 200ha dairy platforms milking 1100 cows on either side of the Clutha River. They winter all their own cows and replacement stock, plus about 100 beef cattle and 1000 romney ewes, and have two run-off blocks to support their dairy units.
After their dairy conversion, the Lucases were looking for a sheep breeding venture with a point of difference that had a future in modern farming.
‘‘With the conversion to dairying on a developing property, we didn’t want something that was going to occupy the higherproducing land,’’ Kerry says. ‘‘The best land was earmarked for dairying because that offered the best return, so we needed something on the balance of the farm that complemented the wintering, cropping and beef aspects of our operation.
‘‘We were looking to maximise returns from our sheep and we were looking for a breed suitable for hogget mating as well as a highproducing terminal sire for the commercial ewes.’’
The dorper appealed to them as an adaptable type of sheep and an ideal hogget-mating sire in a region strongly focussed on traditional English breeds of sheep.
What stood out was its low birthweights, mothering ability, fast growth rates of lambs and high meat yields.
The couple set up the Rivermoor White Dorper Stud in 2003, based on Kaya genetics from Australia and Sunnyvale genetics from top dorper breeders and family friends Bill and Maureen Lott, from Fairlie, who introduced the breed to New Zealand.
Since then the Lucases have introduced new bloodlines from Australia most years because stock numbers and the scale of the industry across the Tasman offers them the opportunity to expand their genetic base. The mix of New Zealand and Australian genetics has resulted in pleasing gains in conformation and carcass qualities.
Most of Rivermoor’s stud ewes and hoggets are artificially inseminated with Australian bloodlines. Genetics from Etiwanda at Cobar have had a strong influence on breeding in recent years and premium New Zealand genetics are also favoured.
‘‘It is important not to lose the many great adaptations we have already made to dorpers in New Zealand,’’ Kerry says.
The biggest challenge the Lucases have faced has been adapting the breed to the cooler, wetter climate of South Otago, which Kerry says is ‘‘probably as wet as anywhere in the country to run dorpers’’.
The Clutha Valley has an average annual rainfall of about 850mm.
‘‘Stock had to have good survivability, but also had to have good growth rates, adapt to wetter conditions and have good longevity as well,’’ Kerry says. ‘‘They had to be able to stand commercial conditions and still yield and perform at a good level.’’
All of these traits don’t necessarily go hand in hand, she says, and it has taken 14 years of selective breeding and heavy culling to establish the quality of base stock required for a small stud flock of 50 breeding ewes. ’’We’ve kept it small because there’s so much going on in this business,’’ Kerry says. ‘‘We definitely want to do it commercially and we want to do it as well as we can.’’
The couple recognised an opportunity to sell two-tooth dorper rams locally as terminal sires for hogget mating in South and West Otago, a traditional sheep farming region renowned for producing some of the best sheep in the country.
‘‘We’re adapting a sheep to fit into commercial sheep farms and provide our clients with a reliable breed for hogget-mating to generate extra revenue without making it hard,’’ Kerry says.
The couple say low birthweights of their dorper lambs minimise damage to hoggets at lambing. Lambs get to their feet quickly to suckle in challenging weather conditions, ensuring high survival rates without intensive farmer intervention.
Dorper lambs are consistently yielding at least 7 per cent more meat than the traditional English breeds the couple and their clients are farming.
Kerry says all farms have financial targets to meet and if the extra revenue from hogget mating is attainable, sheep farmers should consider it.
Moor Farm has consistently recorded in excess of 100 per cent hogget lambing from dorper rams.
‘‘In a business this size at that time of year, we are too busy to be intensively shepherding and the feedback we get from our clients is they don’t have to assist the number of hoggets every day on their rounds that they did prior to using dorpers. There’s always one or two they will have to help lamb.’’
Following their success in the show ring at Fairlie, Kerry is confident they now have the base they were looking for to increase the size of their dorper breeding flock in future.
She says the experience of developing this breed for southern conditions has been a great challenge and a good experience.
‘‘It’s a good excuse to follow our passion and it’s always rewarding to see things improve.’’
It is important not to lose the many great adaptations we have already made to dorpers in New Zealand. Kerry Lucas