8 minute read
The DNA Difference, How Genomics Can Help You Pick Your Best Animals
WORDS // DAIRY AUSTRALIA
INCREASING numbers of Jersey breeders are using genomics to better target their sexed semen, with the information from DNA testing providing another tool to assist on-farm decisions.
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This comes as recent DataGene analysis of Jersey heifer calves revealed an average difference in Balanced Performance Index (BPI) of $276 between the best and worst animals within individual groups.
No group of calves in this analysis had a range that was less than $100 BPI between the genetically superior and inferior animals, showing the importance of retaining the best heifers to achieve the most genetic gain.
The BPI is an economic index used by DataGene to measure the lifetime contribution of vital genetic traits such as production, type, health, fertility, longevity, workability, and feed efficiency to a farm business.
DataGene Project Lead – Genomics Michelle Axford crunched these Jersey numbers and said the range in the BPI and Australian Breeding Values (ABVs) demonstrated the value of using genomics to make more informed decisions.
“The main thing these numbers are telling us is that there is enough difference in groups of Jersey calves, that we need to genomically test to distinguish the top from the bottom,” she said.
“It’s risky to select calves at a young age without genomic data. Choosing the wrong heifers to breed replacements from, or to sell, can leave a costly and lasting impact on a herd.”
Genomic testing reliably predicts the future performance of young heifers as the test results are the equivalent of having seven lactations worth of data.
Michelle said many farmers have been surprised with their calves’ genomic results, as in calf pens the individual animals aren’t considered as being too different.
The DataGene analysis included Jersey calf cohorts born after 2019. These animals came from 64 groups of calves and the average number of calves per group was 51.
These calves had an average BPI of $145. The best and worst animals had an 11 per cent difference in Daughter Fertility and 10 per cent different in Mastitis Resistance.
“An investment of about $50 per calf for a genomic test sorts these differences out at a young age,” Michelle said.
“And then you have the genomic information to use for the lifetime of the calf.”
For context, the difference between the best and worst Holsteins for a six-week in-calf rate is 19 per cent. This larger number reflects a variation of traits in Holsteins compared to Jerseys.
Michelle said choosing Good Bulls* contributed to improving the genetic gain of a dairy herd, but equally it was important to consider the cows from which replacements heifers are bred.
“It’s worth checking – using genomics – to make sure you are breeding your next generation from the right heifers - especially for traits that are hard to see early in life,” she said.
“For example, genomics can help farmers decide which cows and heifers they breed to Jersey sires with sexed or conventional semen and those they breed to beef. As farmers become more strategic with their approach to breeding, using genomic data effectively, the range between the top and bottom animals will likely narrow over time.”
The DataGene Annual Update reported the number of genomic tested dairy females in Australia more than doubled in 2020-21 to 48,356.
Holsteins represented 88 per cent of the females genomically tested last financial year, Jerseys accounted for 9 per cent.
Compared to the breed proportion in herd recorded cows, farmers are genomic testing relatively more Holsteins and fewer Jerseys, Michelle explained.
Farmers that genomically test and collect herd recording, health and classification information contribute to improving the reliability of Australia’s dairy breeding values.
Jersey Australia President and Gippsland breeder Lisa Broad genomically tests her animals and has contributed data towards an industry calf vitality study.
“Genomics is looked upon as a tool and it’s up to each individual farm or business to decide how much importance they are going to place on that tool when it comes to breeding or management decisions,” she said.
Lisa said there has been an increase in genomic testing within the Jersey breed as farmers use the data to help guide decisions such as which animals to sell to export.
Genomics has also underpinned decisions about sexed semen joining and assisted with parentage confirmation.
“If you go out into a paddock and there are 20 cows calving and they all have heifers, verifying parentage accurately is now easy thanks to genomics,” she said. “It’s as simple as taking a notch from their ear for DNA, there’s no stress.”
For more information contact: DataGene 03 9032 7191 or enquiries@datagene.com.au or www.datagene.com.au.
DataGene is an initiative of Dairy Australia and the herd improvement industry.
* To qualify for DataGene’s Good Bulls status, a bull must meet the minimum requirements for Balanced Performance Index (BPI) and reliability and be available for purchase.
Build your skills in farm management. Applications now open for the national Masterclass in Dairy Farm Management. Visit utas.edu.au/tia/study/masterclass-in-dairy-business for course information and to apply.
Creating the future of your dairy herd is made undeniably easier with the right execution of a breeding strategy powered by genomic testing. Genomic testing allows dairymen to rank animals in their herd according to production, type, and health traits, as well as feed conversion efficiency, and identifies animals with potentially beneficial milk proteins or genetic abnormalities. Successfully utilizing genomic testing as a part of your breeding strategy is based on your understanding of the data that is available and how to use the data to make the right breeding decisions.
Why are genomics so valuable to the dairy industry?
Genomics combines pedigree based traditional animal breeding and molecular biology to bring us a tool that allows us to predict future performance on animals that are too young to be progeny tested. There is opportunity to make large improvements in genetic gain by increasing the accuracy of selection with genomic testing. Utilizing genomics in conjunction with other technologies like sexed semen can also rapidly increase genetic gain and therefore profitability in a herd. Since the introduction of genomics into the dairy industry in 2009, there has been a significant reduction in the age at which parents are selected (Figure 1) and more genetic progress in the past ten years than in the previous 50 years in the industry, since the introduction of AI (Figure 2).
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Generation interval (years)
10
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6
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SB DB SC DC
0 1980 1985 1990 1995 2000 2005 2010 2015
Offspring year of birth
Figure 1 shows the decrease in generation interval, or the average age of parents when their offspring is born, of Jerseys for bulls and cow sires since 1980.
Modified from Ato Hagan, B., and Cue, R. 2019. Generation intervals in Canadian dairy cattle herds. Canadian Journal of Animal Science. 100(1): 175-183. https://doi.org/10.1139/cjas-2019-0053
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PTA Value
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Net Merit PTA Value for Jersey
Cow Sire
1975 1978 1981 1984 1987 1990 1993 1996 1999 2002 2005 2008 2011 2014 2019 Birth Year
Figure 2 shows the change in Net Merit (NM$) in the US Jersey population for cows and sires from 1975 to 2019. There has been a huge increase in genetic progress since the introduction of genomics in 2009.
Genomic testing provides commercial dairymen with valuable production, type, and health information that allows them to rank their females based on genetic merit. This allows them to identify their best females to use to make replacements and make other important breeding decisions such as lower genetic value animals being utilized for a beef on dairy breeding strategy to extract more value out of the beef cross calf (Figure 3). Genomic testing can also include important information about markers and haplotypes that can help dairymen propagate the markers they want in their herd such as Beta Casein A2 and BB Kappa Casein while avoiding propagating negative haplotypes in their herd that can decrease fertility and therefore profitability. Beef Semen
Figure 3 Females with the highest genetic merit can be bred to High Purity 4M sexed semen to make replacements, while lesser genetic TM value animals can be bred to beef semen or sold, depending on the market situation.
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Genomic Testing
Create the future of your herd by discussing the Genomic Testing options available with our trusted team.
Genomic values provided by CDCB / DataGene ☑ Number of Traits 75
Production
6
Health & Longevity
22
Conformation
21
Selection Indices
5
Milk Markers Kappa Casein Beta Casein A2 Beta Casein AB Beta Lactoglobulin
Kappa Casein Beta Casein A2 Beta Casein AB Beta Lactoglobulin
Kappa Casein Beta Casein A2 Beta Casein AB Beta Lactoglobulin
Markers Package
19 included****
Parentage Discovery ☑ ☑
20
Milk Yield, Fat Yield, Fat %, Prot Yield, Protein %
Productive Life, Liveability, SCS, DPR
UDC, FLC, BSC
NM$, CM$, FM$, JPI, TPI
Available for upgrade Australian BPI Indicies ☑
50
6
13
26
BPI, HWI, ASI
Genomic Testing Pricing: Vision75 $55 Vision20 $40 BPI Indicies $52 Vision 75 + BPI Indicies $75
Note: All pricing is exclusive of GST and is subject to change without notice.
Assisting Farmers with Genomic Testing.
Genomic Services available include:
Genomics on BPI, TPI, JPI and LPI bases A2 Testing and Full Milk Protein Testing Polled, JH1, BVD Testing Nominating key replacements Early specification of export heifer candidates Assistance on farm with sampling
One sample, one simple comprehensive solution.
Working with the local leading Australian genomic laboratory “Neogen Australasia” to support your breeding and export decisions.
For more information on the range of testing options available contact:
Total Livestock Genetics (03) 5593 2016 genomics@tlg.com.au Neogen Genomics Territory Manager Chris Hoffmann 0427 167 148 CHoffmann@neogen.com
