Lameness – causes and cures
The Economic and Health impacts of lameness are significant, so knowing how to minimise, treat and prevent it is crucial. one publication is essential reading where this is concerned, writes Matt O’Keeffe
One of the most practical and informative publications to issue from the Moorepark dairy levy-funded research programme in recent years is the Reducing lameness in Irish herds manual. Compiled by Dr Muireann Conneely, Teagasc Moorepark, in association with Ned Dunphy, Waterford Farm Relief Services (FRS), and Ger Cusack, a vet with Comeragh Vets, it is an essential guide to preventing, minimising and treating lameness in cows.
Financial loss
The economic and health impacts of cow lameness are often not fully appreciated on dairy farms. A Teagasc study quoted in the Moorepark publication illustrates its effects. On average, one in 10 cows on Irish dairy farms is lame at any one time with the worst affected herds having between 15-30 per cent of cows in the herd lame. The report cites data (Ryan and O’Grady, 2004) that estimates the financial loss for every lame cow in a herd at €300. The financial losses include lower milk production, reduced fertility, treatment costs and increased culling because of lameness. And it is most likely that those losses have risen significantly in the intervening two decades.
Health and welfare
Aside from the financial implications, cow lameness poses a major health-and-welfare issue. Milk producers’ licence to farm is based, in no small part, on how well livestock are managed and cared for. As the publication asserts, 'improving dairy-cow welfare by reducing lameness is critical to retain societal support for dairy farming’. In addition, the authors stress the demoralising effect on herd owners and staff looking after the affected cows.
Sustainability in all its guises is paramount on today’s farm, but this publication highlights the lower sustainability credentials of a milk-production farm because of the increased emissions caused by additional cow culling, often at a young age, as a result of lameness. That shorter lifespan results in more cows being required to produce the same volume of milk. With an increasing emphasis on lowering antibiotic use on farms to help counteract antimicrobial resistance, the need to treat some lame cows with antibiotics must be minimised, according to the publication.
A complex issue
After outlining the implications of cow lameness, the publication devotes most of its space to advising on prevention of lameness, minimising its prevalence and on actions to be taken to cure the problem when it arises. Lameness management does not have a ‘one solution fits all’ approach. There are varied forms of and reasons for lameness, ranging from inadequate farm structures, as well as physical and bacterial vectors. In assessing all of these issues, the publication does assert that lameness, both its prevalence and severity, can be reduced by adopting a range of measures, many of them straightforward, practical, and low cost.
While hip or leg problems can cause lameness, the vast majority of lameness cases in cows are associated with the foot, specifically the hind foot. The primary causes of foot-located lameness, the publication states, include both infectious and non-infectious hoof lesions, with the majority falling into the non-infectious category. These include white line disease and sole haemorrhages. White line disease can be caused by ‘physical trauma that bruises the horn’. It is also caused by shearing forces acting on the white line such as twisting and turning on a hard surface and loose stones or grit penetrating the white line, according to the manual. Ultimately, an abscess can form in the area where the hoof is compromised. The causes are varied, but can include surface conditions in farm buildings, roadways and paddock access and egress points. Putting it bluntly, as the manual authors do, wet and muddy conditions increase the likelihood of white line disease infection as a cause of lameness in herds.
The cow’s diet can also leave cows vulnerable to white line disease. There is a direct connection between poor diet quality and an outbreak of infection. It should be emphasised that there is a distinct difference between feed volume and feed quality, with the nutrient value of the diet being a determining factor in hoof health.
Calving period & hoof condition
Another common cause of lameness involves sole bruising and haemorrhages, which, again, can have a variety of causal factors, some interconnected. At calving, for instance, according to the manual: “The connective tissue attachments that hold the pedal bone within the hoof capsule become weak and loose, allowing the pedal bone to sink and put pressure on the germinal cell layer between the pedal bone and the sole horn.” That is a natural phenomenon and reducing cow movement over long distances and on hard surfaces, in the immediate aftermath of calving, is recommended.
Weight loss and lameness
Where condition score is not managed optimally, the risk of lameness developing is also increased, as the physical health of the hoof can be impaired in the event of sudden and significant weight loss. Long periods standing on concrete is another lameness vector identified by Dr Conneely and her colleagues as giving rise to sole bruising and haemorrhage.
Correct treatment
Ultimately, the adoption of preventative measures will not entirely eliminate lameness. Where it does arise, as with most health issues, effective treatment of lameness in cows through early intervention leads to the best outcomes. The advice is clear and concise: “Correct treatment by a trained person ensures a faster recovery. If you have not received training in the correct treatment for lameness, contact your vet or hoof trimmer for advice." As a general rule, lame cows should be managed in a manner that reduces pain and stress on the animal and minimises further deterioration of the impacted hoof: “All lame cows should be kept on a soft surface, walking distances should be minimised and anti-inflammatory pain relief should be given, as required,” according to the publication.
As all livestock managers are aware that 'antibiotics should only be used after receiving veterinary advice where a diagnosis has been made’. Suggestions for practically implementing these minimal walking protocols may include once-a-day (OAD) milking of lame cows, or, depending on the time of year – late lactation for instance – or lameness severity, premature drying off.
It’s not the cow
It should be emphasised that most of the causes of cow lameness are at one remove from the cow herself. Poorly constructed or badly maintained roadway surfaces allied to increasingly longer walks to and from the milking parlour, as herd sizes increase, are a particular cause of lameness. Stones, muddy sections, too many turns and bends, cows being forced to move too quickly, narrow roadways, all contribute to an increased risk of lameness. Even where surfaces are comfortable for walking, excessive periods of standing, in collection yards, cubicles or at feed rails, are also conductive to the development of lameness problems.