Genomic selection increases cow health and longevity (Nov/Dec 2021)

Analysis of key production and performance parameters shows that using genomic test data effectively can improve herd health, efficiency and longevity. Read on to find out what it could do for your herd.


TEXT SARAH ALDERTON



Selecting replacement heifers using the CLARIFIDE Plus Dairy Wellness Profit (DWP) genomic index leads to healthier and longer-lived cows and calves, according to data from 1,390 animals.


Vet Neil Eastham, a partner at Bishopton Veterinary Group and RAFT Solutions in North Yorkshire, carried out the study to analyse key production and health parameters from animals on two farms in the North of England where CLARIFIDE Plus testing had been carried out.


Key parameters


Records were collected from 746 CLARIFIDE Plus tested animals, which calved during a three-year period, from one herd. Analysis of the data found heifers ranked in the top 25% based on DWP had:


● Lower levels of mastitis. Just 6% of heifers ranked in the top 25% on DWP had one or more cases of mastitis in their first lactation versus 12% for heifers in the bottom 25%. Across all lactations, the difference was 20% of animals in the top 25% having one or more cases compared to 41% in the bottom 25% (See Figure 1). This was a difference of 95 cases of mastitis between the top and bottom quartile groups, at an estimated cost of £23,750.



Figure 1: Mastitis incidence in the top and bottom DWP quartiles


● Lower levels of intramammary antibiotics to treat mastitis infections were used. Across all lactations, the difference in antibiotic use between the top and bottom quartile groups equated to an estimated additional 1.17mgPCU (population correction unit) per cow, or an extra 285 intramammary antibiotic tubes used in the bottom 25%.


● Fewer cases of lameness. Across all lactations, 37% of animals ranked in the top 25% on DWP had one or more cases of lameness versus 55% for those in the bottom 25%. The higher lameness incidence across the bottom 25% of animals ranked by DWP resulted in an additional lameness cost of at least £10,890.


Survival data


Survival data from 317 tested animals, from a herd that has been genomic testing all heifers born since 2015, was also analysed. Mr Eastham found heifers ranked in the top 25% based on DWP had


● Improved survivability. The productive life of heifers in the top 25% for DWP was consistently longer than that of their lower DWP herd mates (see Figure 2).



Figure 2: Heifer longevity in the top and bottom DWP-ranked quartiles


● Higher lifetime daily yields. The top 25% group not only produced milk for longer, but they also yielded, on average, 2.6kg more milk per cow per day compared to the bottom 25%, which averaged 13.8kg compared to the bottom group at 11.2kg.


● Calves also had fewer cases of calf pneumonia. Out of 644 calves, monitored during a 20-month period, there were 66 extra cases of calf pneumonia in calves ranked in the bottom 25% for the wellness trait calf pneumonia compared to those ranked in the top 25%.


The use of the DWP selection index, which is provided as part of the CLARIFIDE Plus offering (along with the standard AHDB UK evaluation), allows producers to accurately select for both calf and cow wellness traits, alongside traits for production, fertility and efficiency (see Figure 3). “Genomic test results are significantly more reliable than traditional parent average values as they reveal more about the genetic potential an animal inherited,” says Mr Eastham. “Using genomic testing reveals an animal’s genetic potential early in life. This means genetic progress can be accelerated with confidence.”

Figure 3: Dairy Wellness Profit comprises six key parameters


“The introduction of CLARIFIDE Plus has improved our understanding of what good genetics look like, as it includes a full range of wellness traits which have been shown to have a huge influence on herd health and profitability,” adds Zoetis’ ruminant veterinary consultant Josh Batterham.


"We want to continue to support efforts to grow the UK genomics market and help producers understand the huge gains that can be achieved from using genomics within their herds. A set of test results is just the starting point; it is essential that producers paying for a genomic service receive good advice on how to best implement those results.”


New-user offer


Producers can benefit from a new-user offer – when they buy three CLARIFIDE Plus tests, they get one test free. This offer is available to new users only and will be limited to the first 100 tests submitted in a single batch from any one farm.


Josh Batterham

Vet Josh Batterham is the genetics technical lead for Zoetis in the UK. Having spent six years in clinical farm animal practice, in South Wales and Gloucestershire, Josh is now looking to improve dairy cow health, welfare and productivity by helping producers make better breeding decisions with the help of genomics.



Ask Josh...

Have any questions about genomics? Get in touch by emailing: joshua.batterham@zoetis.com


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