Breeding for Better Claw Health

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 How does it work? can improve through selection. Recording relies on a simple principle. The claw trimmers score the Although the heritability for four most common diseases as mild or severe: (inter) digital claw disorders is rather low in dermatitis, heel horn erosion, sole haemorrhage and sole ulcer. Sole comparison with milk haemorrhage and sole ulcer are indicators of laminitis but the production, but it is higher than Swedish are anxious to record symptoms and are not making any for other diseases such as premature assumptions. Sole ulcer is scored per foot while the others mastitis. The heritability is are scored per cow. Also lameness is scored as mild or severe. Claw sufficient to justify breeding conformation, treatment and other diseases such as double sole are for better claw health. reported and coded with a letter. Moreover, there is space on the form The research from Viking to make a remark but this is not scanned to the database. “It is Genetics shows that there is a important that every claw trimmer agree on the scoring, to produce clear correlation between the reliable breeding values. The claw trimmers are continuously Swedish breeding value ‘claw educated, but of course the quality of the data can always be health’ and longevity. Thus, improved upon and commitment to record keeping varies, says the breeding for better claw health developer of the system, Christer Bergsten, researcher at Swedish increases the longevity of the University of Agricultural Sciences and Swedish Dairy Association. cows.

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