So I delved into some of the available research on the pasture-based to winter-housed system often practiced in Ireland. Here's a few interesting facts I unearthed.
From Olmos et al, 2009, Livestock Science;
• Previous research has indicated that pasture-based systems operated in Ireland and New Zealand have an annual incident of lameness of 28pc (range 4pc to 54pc) which is similar to the level seen in housed systems 21pc (range 2pc to 54pc). However, access to pasture has also been reported to reduce the level of lameness and risk of claw disorders
• Poor roadways, long walking distances, poor herding skills and sub-optimal dry matter intakes are causes of lameness in the pasture-based dairying system;
• Cows' hooves require a minimum of 85 days at pasture to recover from the housing period and calving event which reduce the resilience of the hoof to mechanical and chemical stressors; • From day 85 post calving to the end of lactation, the pasture-based cow has less hoof disorders, better locomotion ability, and reduced likelihood of clinical lameness compared to the housed system;
• Pasture system facilitates longer undisrupted lying times that have beneficial implications for lameness and therefore welfare;
• Infectious causes of lameness show the quickest and greatest decline at pasture, with the severity of digital dermatitis being easily resolved if contact between slurry and infectious agents are reduced;
• White line disease (WLD)is recognised as a sub-clinical or chronic manifestation of laminitis, while haemorrhages and sole ulcers are indicators of constant mechanical insult.
From Somers and O'Grady 2015, Irish Veterinary Journal:
• White line disease is the most common foot lesion; • Grazing system decreases the risks of sole ulcer, digital dermatitis and other infectious lesions but increases the risks and incidence of white line disease and sole haemorrhage compared to housed cows. WLD incident increases especially if grazing by day and housed by night;
• Severity of lesions and disorders in housed cows are higher, probably due to cumulative effects of walking or standing on concrete, contact with slurry or unhygienic conditions;
• On average 58pc of lameness is caused by non-infectious lesions, 35pc caused by infectious lesions, but dependent on the farm;
• Ninety per cent of lesions were found on the hind feet, 12pc on front feet and 8pc had lesions on both;
• Eighty one per cent of lesions on front feet are on the medial (inside) claw, whereas 63pc of lesions on the back feet are found on the lateral (outside) claw.
Lameness is a major economic problem and a welfare issue for both cow and herdsman.
So what can we conclude is this;
1. Irrespective of system, lameness is a significant cost in Irish dairying. If more than 7pc of your cows in one year are lame there is a lameness problem in your herd.
2. Lameness is not an easy problem to fix, there is never one solution, and problems vary from farm to farm.
3. Knowing the cause of lameness and incident level on your farm may facilitate in creating a plan on how to reduce it.
4. Infectious causes of lameness have an increasing impact during the housed period. If you have an incidence of them, devise a treatment plan. Reduce slurry contamination and improve hygiene.
5. The severity of lesions are greater in housed cows so intervene and treat lame cows ASAP.
6. If sole haemorrhage, white line disease and sole ulcers have been a significant cause of lameness this year, consider repairing roadways where needed. Wet boggy areas are a no no. Also consider how are you herding cows? Are the cows pressured at any point?
7. If white line disease was the main lameness ailment, consider how you managed the cow's diet. Was it energy deficient, where there dietary changes?
I believe that prevention is the key to having real success with lameness. Focus on what you can control by identifying key areas of farm infrastructure, cow management/handling, and nutrition.
Mary Kinston is a discussion group facilitator and consultant, and farms with her husband in Kerry