Selecting for Mastitis Resistance
Selecting dairy bulls with mastitis resistance can help fine-tune mastitis management in the long term.
Dairy Australia's Countdown project leader John Penry said although most mastitis control is achieved through management practices and the environment, genetics does have a small influence on mastitis resistance.
"Genetic variation for cell count exists and some bulls have been found to produce daughters which are more resistant to mastitis than others," Dr Penry said.
While the heritability of mastitis resistance is relatively low at 10 percent, the benefits are permanent and accrue with each generation.
This means an estimated 10 percent of the variation in the Australian dairy cow population is due to genetics and the other 90 percent is due to the management environment of the cow.
"For little or no cost you can make a long term difference to the level of mastitis in your herd by selecting bulls from the mastitis resistance list in the Good Bulls Guide," Dr Penry said. Australian Breeding Values for mastitis resistance – cell count ABVs – are available for AI bulls, based on their daughters' cell counts.
Improving mastitis resistance involves selecting bulls with a Cell Count ABV which is more than 100 – the higher the Cell Count ABV, the greater the mastitis resistance.
The difference between the best bull (Cell Count ABV of 171) and the worst bull (Cell Count ABV of 20) is estimated to be $100 net profit per cow per year. Most bulls have a Cell Count ABV between 78 and 122.
Cell Count ABVs are incorporated in the Australian Profit Ranking because mastitis lowers farm profitability.
"If mastitis is part of your breeding plan then look at a bull's Cell Count ABV, or use the mastitis resistance list in the Good Bulls Guide," Dr Penry said.
For a fact sheet on the impact of genetics on mastitis and cell counts, please visit the Dairy Australia website, www. dairyaustralia.com.au/countdown and type 'genetics' in the
search box, or telephone Countdown Downunder on (03) 9620 7283.
The ADHIS Good Bulls Guide is available from www.adhis.com.au.
Countdown is an example of your levy at work. For more information on this and other examples of your levy at work visit www.dairyaustralia.com.au
2012 AUSTRALIAN DAIRY CONFERENCE IS SET TO BE THE BIGGEST AND BEST YET!
As we celebrate 10 years of the Australian Dairy Conference culture, the plans are building for delivering what we think will be a truly memorable event in the heart of Gippsland dairying country, an hour east of Melbourne.
The 2012 conference programming committee is nearing the end of its planning process and expects to release the final program by mid November. Be sure to register your interest to receive information as soon as the program is finalised.
The biggest event on the dairy industry calendar, the Australian Dairy Conference, will be held in Gippsland in February 2012. The conference, which attracts more than 450 delegates, will be book-ended by tours:
- Monday, February 20 – tour departing Melbourne for East Gippsland
- Tuesday, February 21 – tour continues, returning to Warragul for the official opening function at Tom Reid Oration at the Warragul Arts Centre
- Wednesday, February 22 – conference day 1 and Elanco BBQ dinner at Lardner Park
- Thursday, February 23 – conference day 2 at Lardner Park, followed by Rabobank Gala dinner at Kernot Hall
- Friday, February 24 – visit to Ellinbank Research Centre
The event sponsorship and exhibition prospectus is on the conference website.
For more information, please contact Esther Price 1800 177 636 or visit www.australiandairyconference.com.au
