The genetic merit of Pat and Diane O’Keefe’s dairy herd has made steady improvements since
2001.
Much of this gain has been achieved by inseminating maiden heifers so that their first calves can be kept as replacement stock. It’s a strategy that has been recommended by geneticists for years, as a way to fast track genetic gain. But it’s easier said than done.
Each year, since 2001, the genetic merit of the herd has lifted more than $7 profit (APR) per cow per year. At an average APR of $54, the youngest of the milking cows are expected to contribute twice the profit of the National average of all herd recorded Holstein cows of the same age ($27
APR).
Inseminating maiden heifers helps in two ways. Firstly it increases the number of replacement calves available, and that allows more opportunity for culling. Secondly, it reduces the generation interval (number of years between mother and progeny). Heifers represent the most modern genetics in the herd, and their progeny are available a year earlier if they are inseminated and their calves kept as replacements.
The O’Keefes dairy at Winslow, near Warnambool, in Victoria’s Western District, milking about
650 cows and rearing about 175 calves each year.
The herd calves over about 10 weeks, from mid May to the end of July, but the O’Keefes work hard to have as many cows as possible calving early. And they join the heifers to start calving about a fortnight before the main herd.
The O’Keefe’s success with inseminating heifers relies on excellent calf rearing and heifer nutrition so that they achieve their target mating weight by 14 months of age, or even younger for later born calves. Heifers are weighed every six to eight weeks to monitor growth rates. A high-protein hay supplement such as vetch is provided if the available feed looks limiting or if growth rates are below target.
The O’Keefe’s program involves synchronising the heifers followed by blanket artificial insemination (AI) performed by a technician. To ensure their calves can be used as replacement stock, heifers are inseminated with Holstein semen. But they only get one opportunity to get in calf to AI. After that, a jersey bull runs with the heifers.
The approach has been successful: this year about 53% of the heifers got in calf to AI, providing about 60 extra replacement heifers.
The synchronisation/blanket AI approach also achieves a tight calving pattern with more than half the maiden heifers calving in the first three weeks from their start of calving, and 70% have calved

50
40
30
20
10
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2000 within the first six weeks. This gives them extra time to recover from calving and to start cycling by joining time, setting them up for a lifetime of high fertility.
ADHIS is an initiative of Australian Dairy Farmers’, that receives the majority of its funding from
Dairy Australia through the Dairy Services Levy.
For more information contact Michelle Axford at ADHIS ph (03) 8621-4240 or email maxford@adhis.com.au.
ENDS
Caption : The genetic merit of the O’Keefe’s herd has improved steadily every year since 2001.
60 O'Keefe APR Trend
2002 2004 2006 2008 2010
Photo:
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Caption: Pat O’Keefe has boosted genetic gain in his herd by inseminating maiden heifers so that their first calves can be kept as replacement stock
(background information for media)

The Australian Dairy Herd Improvement Scheme (ADHIS) is an initiative of the Australian Dairy Farmers (ADF) to assist genetic improvement in the dairy industry. ADHIS maintains a national database of performance and pedigree details for individual dairy animals. The data base is used to generate Australian Breeding Values (ABVs) which indicate a cow or bull’s potential genetic merit (ie it’s breeding value to a dairy herd).
Genetic gain has increased significantly since 1983 when farmers began utilising ABVs. Each year the genetic merit of artificially bred cows is increasing, worth about $9.40/cow/yr in extra profit. The value of these gains to the industry is approximately $20 million per year. ADHIS is partly funded by farmer levies through Dairy Australia.
ABVs and ABV(g)s are produced for a variety of traits including milk yield and composition, workability and survival as well as profitability. Updated
ABVs are released twice a year (April and August) for use by dairy farmers and artificial breeding companies. ADHIS also releases ABV(i)s for foreign bulls three times per year (January, April and August).
ADHIS is an initiative of Australian Dairy Farmers’, that receives the majority of its funding from Dairy Australia through the Dairy Services levy.