Herd improvement company CRV Ambreed has announced what it says is its best bull team ever to breed facial eczema-tolerant cows.
New Zealand endured one of the worst facial eczema (FE) seasons in years in 2016 when spore counts ballooned in the North Island and parts of the South Island to the highest in a decade, and many herds had a large number of cows with clinical facial eczema.
CRV Ambreed says that caused a tripling of orders for straws of semen from bulls with genetics for a tolerance to facial eczema. Tens of thousands of straws were sold in 2016 and the firm’s global product manager for grazing, Peter van Elzakker, says CRV Ambreed is expecting demand to increase again in 2017.
He says the daughters of CRV Ambreed’s FE-tolerant bulls are 25%-30% less reactive to a facial eczema challenge than the average bull and the just-announced 2017 CRV Ambreed FE bull team is the best yet. The number of CRV Ambreed bulls with “high” or “very high” tolerance to FE has jumped from 18 in 2016 to 25 this year, Mr van Elzakker says. “In addition, the number of bulls with daughter proofs in the team has jumped from 8 to 12.”
Mr van Elzakker says the top bulls in the new team are also high-indexing, with excellent all-round traits. He says the 2017 team has an average Breeding Worth (BW) of 156, compared with the New Zealand herd average of 67 BW (NZAEL, November 2016). “These CRV Ambreed bulls have high protein, fertility and type so there is little trade-off in index for farmers who are looking to breed cows with a superior tolerance to facial eczema.”
New additions to the team are Jersey sire BENJI and Friesian sire RUSSO. Both are high-indexing proven bulls who will make the 2017 portfolio based on their outstanding traits and not just because of their higher FE tolerance.
CRV Ambreed has been offering semen from bulls with an increased tolerance to facial eczema since 2011, following research that discovered how to identify bulls with improved FE-tolerance. Now, about 17% of CRV Ambreed’s 150-strong bull catalogue has increased tolerance to facial eczema, across the Crossbred, Friesian and Jersey categories.
Facial eczema is caused by a toxin (sporisdesim) produced by the spores of the fungus Pithomyces chartarum growing on pasture. The fungus grows in the dead litter at the base of pasture in warm moist conditions, and when ingested by cattle or sheep, damages the liver and bile ducts. It can cause liver failure and death.
Te Awamutu vet researcher Emma Cuttance studies facial eczema and firmly believes genetics are key to a long-term solution. “My message to farmers is get on board now with genetics and do it properly. Don’t just choose one or two bulls with tolerance to facial eczema – you have to do this properly to see the gains and realise that this is important future-proofing for the farm.”
Spore counts are currently rising around the country and dairy farmers will be considering treatment soon. Mrs Cuttance says New Zealand’s zinc supply to treat facial eczema is at times volatile, and she suspects the country won’t always be able to rely on zinc as a solution. She says facial eczema has already spread down the country in recent years to areas such as the top of the South Island and as far down as the West Coast.
CRV Ambreed’s Research and Development Manager Phil Beatson says a genetics approach provides another tool in the toolbox for farmers working in ever-changing environments, particularly in relation to global warming. “Genetic improvement offers a safe, environmentally sound and economic solution. It means less zinc can be used, and farmers can be confident they are breeding long-term solutions for their farms.”
Mr Beatson says it’s estimated that for every three in 100 cows with clinical FE, about 70% of the herd could have subclinical symptoms. “You won’t necessarily see the disease in cows with subclinical symptoms, but it will be damaging the liver and negatively impacting milk production.”