Breeding for better claw health
Jan-Åke Eriksson ‘Type traits feet and legs is not enough’
Sweden has promoted breeding for healthy cows, maintaining high production for several
decades. In 2006 a breeding value for claw health based on data recorded by hoof trimmers
started to be included in the health profile. ‘Claw problems are a big problem for the dairy
farmers all over the world.’ Dr Menno Holzhauer, expert on cattle health from the Animal
Health Service Deventer (GD). ‘Generally 70 - 80% of the dairy cows in Holland have one or
more claw disorder.’
Lameness has a positive genetic correlation with milk and protein yield. So breeding for
increased milk and protein yield affect claw health negatively, unless resistance is included in
the selection criteria. Dairy cows that can ambulate freely and easily are very important. Good
claw health is not only important for the cow, but also for the farmer. The consequences of
lameness in a cow are significant. The economic cost of a lame cow caused by a sole ulcer is
calculated around €500 euro in Sweden, 600 dollars in the USA, 200 NZ dollars (100 euro) in
New Zealand. Examples of direct costs are the bills from the claw trimmer and or the
veterinary surgeon. Indirect costs are reduced milk production, culling/replacement cost,
reduced fertility and time dedicated to manage lame cows. There is a negative impact on the
cow’s welfare as she is in pain.
Lameness is the biggest reason for culling after fertility and mastitis in most countries. A
proportion of poor fertility is probably caused by lameness, because lameness affects the
fertility of the cow negatively. ‘Herdsmen in the USA underestimate the number of lame
animals. There are 2.5 times more lame cows than producers though were present in their
herds.’ Says C. Guard a recognized expert on cattle hoof care and a member of the production
medicine group at Cornell University’s school of veterinary medicine.
However, dairy farmers should not overestimate the role of breeding; feeding and
management are most important in a short perspective. Breeding is a long-term investment.
‘But many small steps, accumulate into one big step,’ says Dr. Hans Stålhammar, chief
geneticist of Viking Genetics.
Type traits are not enough
‘Breeding for type traits like foot angle or a better rear leg side view will not help to reduce
claw problems in dairy cattle,’ says Jan-Åke Eriksson researcher responsible for breeding at
the Swedish Dairy Association. Research at the Swedish Agricultural University has shown
that the genetic relationship between feet and leg type traits and claw disorders does not
correlate for most traits in Swedish Holstein or low for Swedish Red. Thus, indirect selection
for better claw health using type trait data was not found possible. This conclusion is
supported by studies in the Netherlands. The following traits were included in this Swedish
research: rear leg side view, rear leg rear view, hock quality, bone structure and foot angle.
Although the heritability of the combined type traits from feet and legs is relatively low,
locomotion (how the cow walks) may be a good indicator for developing claw disorders at a
later stage in life. However locomotion is difficult to measure.
Moreover, recent research from the Swedish breeding association Viking Genetics on 108
Swedish bulls born in 1999 – 2001 indicated that there was no genetic correlation between the
overall breeding values type traits 'feet and legs' and longevity. So breeding for type traits,
‘feet and legs’, does not contribute to an increase in the proportion of cows that calved a
second, third and fourth time, as is the definition of longevity in Sweden.
Claw health
Rather large number of
Swedish hoof trimmers record
the claw disorders of every
cow in the herd at maintenance
claw trimming, monthly almost
20.000 cows are scored. This
data is used to retrieve an
estimated breeding value for
claw health and is presented
six months after the first total
merit index. Four main
disorders are included in the
breeding value, see frame:
‘How does it work.’ Sole ulcer
counts for 50% of the breeding
value, because of its high
economic and welfare value.
The systems works in a direct
way: a bull will get a lower
breeding value for claw health
if his daughters have more
claw disorders. There is a large
variation in claw health
between the bulls, which
means that the trait claw health
can improve through selection.
Although the heritability for
claw disorders is rather low in
comparison with milk
production, but it is higher than
for other diseases such as
mastitis. The heritability is
sufficient to justify breeding
for better claw health.
The research from Viking
Genetics shows that there is a
clear correlation between the
Swedish breeding value ‘claw
health’ and longevity. Thus,
breeding for better claw health
increases the longevity of the
cows.
How does it work?
Recording relies on a simple principle. The claw trimmers score the
four most common diseases as mild or severe: (inter) digital
dermatitis, heel horn erosion, sole haemorrhage and sole ulcer. Sole
haemorrhage and sole ulcer are indicators of laminitis but the
Swedish are anxious to record symptoms and are not making any
premature assumptions. Sole ulcer is scored per foot while the others
are scored per cow. Also lameness is scored as mild or severe. Claw
conformation, treatment and other diseases such as double sole are
reported and coded with a letter. Moreover, there is space on the form
to make a remark but this is not scanned to the database. “It is
important that every claw trimmer agree on the scoring, to produce
reliable breeding values. The claw trimmers are continuously
educated, but of course the quality of the data can always be
improved upon and commitment to record keeping varies, says the
developer of the system, Christer Bergsten, researcher at Swedish
University of Agricultural Sciences and Swedish Dairy Association.
Advantages of record keeping
Recording data will take extra time and engagement. But, when the claw trimmers are used to
do this, it will only take around 15 seconds per cow. Sometimes the farmers record the
findings of the claw trimmer. The advantages of keeping records of claw disorders are
unquestiable. After every claw trimming the farmer will have a great deal of additional
information that can be used for futurel decisions. For example, many claw problems are
related to the path the cows have to walk to the field. Improving this could reduce lameness, it
would be interesting to observe if there are fewer cows with white line disease (sole
haemorrhage) afterwards. It is also possible to find this information on the internet so the
farmer can see if lameness and claw disorders fluctuates over season and the year and he can
compare his statistics with national figures. The veterinarian and the feed advisor can give
much better advice when they have this information. Also it is much easier to monitor the cow
and look if she is performing well. Furthermore, the breeding organisations are of course very
keen on gathering information on sires that breed better hoof health.
Sires
There are famous bulls with a breeding value for claw health in Sweden. In Sweden the
average is 100 and the standard deviation is 10. This means that bulls with or more than 120 is
at the top 2,5% of the list, this is very high. O-Man: 114, Ramos: 120, Chassee: 104, Lord
Lily: 100, Sabre: 85, Rudolph: 95, Addison: 106, Mtoto: 100, Cash: 112, Dutch boy: 101,
Patron: 84, Winchester: 89.
A clear example of a bull that shows that the combined type traits “feet and legs” are not
related with claw health can be seen on the proof of the Swedish Holstein bull Berte, 122 for
claw health and 82 for feet and legs. Berte has also an excellent daughter fertility (131) and
very good longevity (125)! In the Swedish Red breed, Brattbacka is a good example, 122 for
claw health and 94 for legs, with a good longevity and fertility. The heritability seems to be
good. Brattbacka has four sons with an average breeding value claw health of 116. Another
example is the Holstein bull Gubbilt with 121 for claw health and the average of his eleven
sons is 110.
Using a bull with a Swedish breeding value of more than 100 for claw health, the daughters of
this bull will have less chance of getting lame. Preventing just one lame cow means a more
enjoyable job and can save up to €500 a year! Jan-Åke Eriksson: ‘The Swedish system is the
answer for breeding for better claw health.’
Bertel Kon