No lame excuses: maintaining sound feet and leg condition in dairy cows

It has been long recognised that lameness in dairy cattle is important (Leech et al., 1960). It is usually recognised as coming third to infertility and mastitis as a reason for culling (Whittaker et al.,1983; Enting et al., 1997). Why then, despite numerous workshops and review papers on the subject, do farmers still regularly cite it as being a critical issue on their farms, and why does the incidence appear to be increasing? In this paper, I intend to propose a 3-step action plan to help individual farmers address the lameness problem on their farms.


Moving toward proactive management

This is a part of the issue introduced at this conference last year in ‘Recreating Dairy Cow Management’, which promoted the idea of ‘cow-centric cow management’, i.e. managing the cow from the cow’s point of view. The practical dairy farmer tends to deal with problems as he sees them, or as they arise. It is difficult to do otherwise when you are very busy.

When you are struggling to see how you are going to make a profit, let alone a decent return on capital, it is not easy to think about investing in something with a long-term payback, or something as nebulous as ‘cow comfort’.

However, unless we can make the required switch from reactive management, which treats cases of lameness as they arise, to a proactive approach that takes a preventative view and recognises the holistic nature of cow management (lameness impinges on dry matter intake, fertility, etc.), it is difficult to see how we are going to achieve the full potential of the modern dairy cow.

Lameness will continue to cost the average individual farmer in excess of £23,000 (>$40,000) for every 100 cows (Keating, 2005) and the dairy industry worldwide millions.

Dick Esslemont estimated 16 years ago that the total cost to the UK Dairy Industry was £89.2 million ($156.1) (Esslemont and Wassell, 1990). If we are to overcome this problem, we must move away from quoting averages and ‘the cost to the industry’ (as above) and start making the scale of the problem more relevant to the individual farmer.

First, we must get his attention, “lameness could be costing you as much as 1.25 pence per litre (1 cent per lb)”. Most dairy farmers in the UK would switch buyers for this amount! At that point we can move on to discussing the actual incidence of lameness and the true cost per case.


Identifying lameness

What is the actual incidence of lameness, and is it increasing? Figure 1 plots the reported incidence from a number of different sources over a number of years. It proves nothing in itself, but it makes you think!




Figure 1.Incidence of lameness in dairy cows reported in the literature (Leech et al., 1960; Eddy and Scott, 1980; Whittaker et al., 1983; Collick et al., 1989; Liverpool University Veterinary Dept., 1993; Ward, 1994; Hedges et al., 2001).


The problem with understanding ‘incidence’, is in knowing what people mean by ‘lameness’. Are we measuring, on the one hand, treated cows or, at the other extreme, deviations from the ideal locomotion score? Are the reported figures from a small number of unrepresentative farms? The 70% incidence reported by Hedges from the UK seems staggeringly high and the 60% reported by Ward is based on three herds, albeit over three years. However studies in France (Faye and Lescourett, 1989), Florida (Guard, 1995) and New York (Shearer and Van Amstel, 1998) suggest a mean incidence of around 30%.

Number of cows treated is not an ideal measure. “The definition of clinical lameness in cattle is fraught with difficulty, even among specialists.” (Green et al., 2002). The same authors reported that clinically lame cows had a reduced milk yield for up to four months before diagnosis! This would suggest that earlier diagnosis would be beneficial; and locomotion scoring can provide an answer by identifying cow discomfort before lameness is overt (Table 1).


Table 1. Locomotion scoring guide with suggested targets (% of herd).


To enlarge the image, click here
After Robinson and Juarez, 2003; targets suggested by Steve Berry at UCD



Steps toward solving the problem

STEP 1: IDENTIFY INCIDENCE OF LAMENESS ON THE SPECIFIC FARM

The key is to get the individual farmer to agree to monitor the incidence of lameness on his farm! This is the first step to arriving at a plan of action that he will own and follow.


STEP 2: IDENTIFYING THE IMPACT

Having agreed on the incidence of lameness on a specific farm, the next part of the process is to work out how much the problem is costing that farmer. When looking in the literature for estimates of the cost of lameness, a confusing range of values is found. Esslemont and Kossiabati (1997) in the UK suggested a total cost per case of £246.22 ($430.89); and applying a modest inflation rate of 3%, this equates to a 2006 value of £321.26 ($562.21). In contrast, Keating (2005) asserts that the total cost per case in the Southlands of New Zealand is £495.91 ($NZ 1,264; $867.84)!

Authorities in the US have generally taken a more sanguine view. Ranging from a quoted minimum of £51-57 ($90–100) per case (Ishler and Wolfgang, 1999) to Guard (quoted in Midwest Dairy Business November 2002) suggesting a figure of £172.57 ($302). Peter Robinson (University of California), however, has developed a spreadsheet to predict milk loss associated with variations in locomotion score that suggests that milk losses alone could cost £31.28 ($54.75) per cow over all cows in a herd with an 8% incidence of clinical lameness. This would equate to over £171 ($300) per clinical case for lost milk alone!

Whatever the number quoted, the individual farmer needs to know how much lameness is costing him. Robinson’s spreadsheet will enable a farmer to calculate the cost of milk loss.

To this he must add his figure for the cost of treatments, reduction in fertility and increased culling. Now we have something to work with and to which the farmer himself agrees.

Let’s take a 100 cow herd with a lameness incidence of 30% and assume that the cost of lameness has worked out at £12,000 ($21,000) per herd per year. That is £400 ($700) per treated case (which would seem to be a reasonable assumption if it includes the lost milk production in the subclinical cases). If the herd yield is 10,000 litres (22,000 lb), this equates to 1.2 ppl (just under 1 cent per lb). You should now have the farmer’s attention!

Clearly a reduction to 0% incidence is unrealistic. In Wisconsin, Cook et al. (2004) have suggested that an incidence of 15% is to be expected in well managed herds. I think that this is still too high and that it is reasonable to expect to be able to reduce clinical lameness to 5%. This would still cost £2,000 ($3,500) per 100 cows, leaving a potential benefit of £10,000 ($17,500), 1 ppl (0.8 cents/lb) part of which, obviously, would be invested in preventing lameness. If the farmer invests half of this, he is still 0.5 ppl (0.4 cents per lb) better off… and this figure is net profit!


STEP 3: SCORE THE CAUSES AND FORM A PLAN OF ACTION

A plan of action ideally involves a team consisting of the herdsman, the nutritionist, the veterinarian and the hoof trimmer; and it MUST take a holistic approach, dealing with ALL the issues (Figure 2).




Figure 2.A holistic view of lameness in cattle.


The problem is that each expert has his own beliefs that can blind him to the importance of other issues. A publication from the University of Edinburgh Dairy Herd Health and Productivity Service (Lameness in Dairy Cows: Prevention and Control) states that, for laminitis, “The primary factor is lack of comfortable lying time. No other approaches are going to have a major impact until this is sorted out.” The trouble is that this can be used as an excuse for not taking any other action viz. “I can’t sort out comfortable lying time until I can afford a new free-stall barn….so it is not worth doing anything else.”(!) Instead, identify ALL the issues and then score them on the chart in Figure 3. This approach recognises that ALL issues are important and will be dealt with – as the time and money become available.




Figure 3.A lameness scorecard.


Causes of lameness

What are the causes of lameness, and what can we do about them? Clearly this cannot be a comprehensive review, which will inevitably reflect my own opinions. Briefly considered are genetics, environment, management, infection and nutrition – recognizing that they are all linked.


GENETICS

If you breed animals that have structurally unsound legs and feet, then the incidence of lameness in such cows is likely to be high. This will be accentuated by management and environmental issues. For instance, you are more likely to get away with genetic weaknesses in this area in tie-stall as opposed to free-stall barns.

Particular problems to look out for are high pin bones, which are often associated with an incorrect leg-set at the thurl. Secondly, excessively narrow rumps which, in conjunction with the large udders associated with high yields, will tend to throw the legs out to the side, putting undue pressure on the inside claws.

Breeding companies have now recognised that locomotion score is associated with longevity and are building this into their indexes. Lameness costs money! Make sure that you take account of this in your breeding program.


ENVIRONMENT

Lameness is often the result of an adverse interaction between the cow and her environment. In particular the type and design of her housing and the surface on which she is asked to walk.

Whatever the type of housing, it must allow sufficient comfortable lying time. Lameness is endemic in overcrowded free stall barns and barns with poor stall design. Cook et al. (2004) have proposed a very useful flow-chart for evaluating free stalls (cubicles) and the same authors have shown that, possibly counter-intuitively, sand provides a better surface than mattresses.

Curbs (the step-up to the stalls) should ideally be 15 cm high, and certainly no more than 20 cm. Apart from placing too much strain on the back feet when the cow stands half-in, half-out of the stall, too high a curb increases the risk of damage to the foot if the cow slips from the edge.

Farm tracks and paths should be free of mud and stones and concrete surfaces should be well maintained.

There is much more on this topic but, essentially, the rules here can be determined through the application of common sense and close observation of cow behaviour.


MANAGEMENT

I shall just make one point here. I was once asked by a farmer if I had anything he could add to his feed to solve the lameness problem on his farm. Looking across the yard, I could see the cows standing in three inches of slurry… .


INFECTION

This includes ‘foul in the foot’, digital dermatitis and heel warts. The key lies in keeping the feet clean before and during treatment with the antibiotic of choice. A common mistake is to use inadequate footbaths. Inadequate because they are allowed to get dirty (thus doing more harm than good) or, typically, because they are too short, not allowing enough contact time with the disinfectant.


NUTRITION

The nutrition of the cow affects lameness in two main areas, quality of horn growth and laminitis. Horn growth is influenced by trace elements, particularly zinc, through its involvement in keratinisation. Supplementing the diet with a highly available form of zinc (Bioplex® Zn, Alltech Inc.) has been shown to have a significant effect, reducing lameness scores by 24% (Harris and Elliott, 1995).

It should be stressed that this is not a ‘magic bullet’ and that all the other causes of lameness must be addressed at the same time but, since the recommended rate of 3 g per cow per day costs around 0.6 pence, it would only cost our 100 cow herd £219 ($383) per year out of the £5,000 ($8,750) available to invest in lameness prevention, and is thus a ‘no-brainer’.

Biotin has also been shown to be beneficial and at a cost of around 4 pence (7 cents) per cow per day should also be considered for its longer-term benefits.

Laminitis has two main nutritional causes: excess protein in the diet, and acidosis. Both issues are avoided by feeding a well balanced diet, which should be the goal for reasons other than that of preventing lameness!

The mechanism whereby excess protein in the diet causes lameness is not fully understood. It may be that too much ammonia in the rumen can cause bacteria to die, leading to toxins in the blood similar to acidosis, or it may be that the breakdown products of excess protein themselves include histamines that can cause inflammation of the laminae.

Whatever the mechanism, Manson and Leaver (1989) showed that cows on a lower protein diet with no foot trimming endured similar lameness to those on a higher protein diet with trimmed feet. Since avoiding excess protein in the diet is also beneficial in terms of waste (both financial and environmental), and in terms of its effect on milk urea nitrogen, this is another ‘no-brainer’.

The issue of acidosis is well understood and nutritionists should strive to avoid it through careful balancing of the diet with respect to rapidly fermentable carbohydrate and effective fibre. It is not always possible, however, to get this right for high yielding cows under all circumstances, satisfying the nutrient demands of production being a priority.

In the UK, it is thought that most cows in early lactation are suffering from subclinical acidosis. Under these circumstances, Yea-Sacc^®1026, a rumen modifier that aids in stabilising rumen pH (Williams and Newbold, 1990), is recommended. At a cost of 7 pence per cow per day, the benefits of increased dry matter intake and forage digestibility will be obtained on top of the reduction in lameness. Even if we applied the total cost of feeding Yea-Sacc^®1026 for 365 days per year to lameness prevention, it would still only cost £2,555 ($4,471) out of the £5,000 ($8,750) allocated to invest in this area.

On the other hand, since Yea-Sacc^®1026 has been shown to increase milk yield by about 1 kg per cow per day throughout lactation, giving a return at least double the cost of the Yea-Sacc^®1026….the lameness prevention is FREE. Yet another ‘no-brainer’.


Summary

The key objective of this article was not to list the various causes and preventative treatments for lameness but to propose a mechanism whereby there would be a greater acceptance of the need for action and, indeed, a greater level of action itself. This consists of a way to make the issue of lameness more real for the individual farmer:

1. Identify incidence of lameness on the specific farm.

2. Attempt to apply a cost of lameness to the farm.

3. Devise a plan of action addressing ALL the possible causes.

If these are adopted, it will indeed result in no more lame excuses!


References

Collick, D.W., W.R. Ward and H. Dobson. 1989. Associations between types of lameness and fertility. Vet. Rec. 125:103-106.

Cook, N.B., T.B. Bennett and K.V. Nordlund. 2004. Effect of free stall surface on daily activity patterns in dairy cows with relevance to lameness prevalence. J Dairy Sci. 87(9):2912-2922.

Eddy, R.G. and C.P. Scott. 1980. Some observations on the incidence of lameness in dairy cattle in Somerset. Vet. Rec. 106:140-144.

Enting, H., D. Kooj, A.A. Dijkhuizen, R.B.M. Huirne and E.N. Noordhuizen-Stassen. 1997. Economic losses due to clinical lameness in dairy cattle. Livestock Prod. Sci. 49:259-267.

Esslemont, R.J. and B.R. Wassell. 1990. Incidence of lameness in herds using the University of Reading DAISY Database. Internal Report. Department of Agriculture, University of Reading.

Esslemont, R.J. and M.A. Kossiabati. 1997 Culling in 50 dairy herds in England. Vet. Rec. 140:36-39.

Faye, B. and F. Lescourret. 1989. Environmental factors associated with lameness in dairy cattle. Prev. Vet. Med. 7:267-287.

Green, L.E., V.J. Hedges, Y.H. Schukken, R.W. Blowey and A.J. Packington. 2002. J. Dairy Sci. 85:2250-2256.

Guard, C. 1995. Recognising and managing infectious causes of lameness in cattle. Proc. Ann. Mtg. Amer. Assoc. Bov. Pract. 27:80-82.

Hedges, V.J., R.W. Blowey, A.J. Packington, C.J. O’Callaghan and L.E. Green. 2001. A longitudinal field trial of the effect of biotin on lameness in dairy cows. J. Dairy Sci. 84:1969-1975.

Ishler, V.A. and D.R. Wolfgang. 1999 Prevention and control of foot problems in dairy cows. Penn. State College of Agricultural Sciences. Cooperative extension. Keating N. 2005. Lameness down in smart trials. Rural News (NZ). http:// www.ruralnews.co.nz.

Leech, F.B., M.E. Davis and W.D. Macrae. 1960. Disease, Wastage and Husbandry in the British Dairy Herd 1957-58. HMSO, London, United Kingdom.

Manson, F.J. and J.D. Leaver. 1989. The influence of dietary protein intake and of foot trimming on lameness in dairy cattle. Anim. Prod. 49:191-199.

Robinson, P.H. and S.T. Juarez. 2003. Locomotion scoring your cows: use and interpretation. 2003. www.txanc.org/proc.

Shearer, J.K. and S. Van Amstel. 1998. Claw disorder: the primary cause of lameness in dairy cattle. 1998. Southeastern Dairy Conference, pp. 1-16.

Ward, W.R. 1994. Recent studies on the epidemiology of lameness. Proc. 8th Intl. Syp. Disorders Ruminant Digit., Banff, Canada, pp. 197-203.

Whittaker, D.A., J.M. Kelly and E.J. Smith. 1983. Incidence of lameness in dairy cows. Vet. Rec. 113:60-62.

Williams, P.E. and C.J. Newbold. 1990. Rumen probiosis: the effects of novel microorganisms on rumen fermentation and ruminant productivity. In: Recent Advances in Animal Nutrition (W. Haresign and D.J.A. Cole, ed). Butterworths, London, p. 211.