Cattle Lameness and Hoofcare 3rd Edition: An Illustrated Guide

Roger Blowey

• Publisher: 5m Books
• Year: 2015
• eBook ISBN: 9781789180398
• Topic: Medicine
• Subtopic: Veterinary Medicine

Lameness is one of the main conditions affecting cattle and is considered a major welfare problem with significant impact on animal productivity. This well-established practical book explores the issue and provides a fundamental guide to prevention and hoof care. In particular, it covers the incidence and costs of lameness, the structure of foot, with its function and possible inflammation, hoof trimming, and the treatment of common diseases.Authored by one of the field's research leaders, the 3rd edition includes updates on hoof trimming protocols, new insights on the structure and function of the digital cushion, and an examination of diseases such as digital dermatitis and sole ulcer.Expert practitioners as well as students will benefit from this new edition of Cattle Lameness and Hoofcare, being an ideal resource for cattle farmers, hoof trimmers and vets.Roger W. Blowey BSc, BVSc, FRCVS, FRAgS, Specialist in cattle Health and Production (Dairy), is known as one of the world's leading veterinary practitioners, operating in the field of Lameness.Author of a range of scientific papers and textbooks, including A Veterinary Book for Dairy Farmers, Roger's work is mainly associated with fertility, mastitis and lameness control programmes in dairy herds.

Chapter One
The Incidence and Costs of Lameness

Incidence of Lameness

Lameness, as every farmer knows, is a major cost to the dairy herd. This ‘cost’ has three main components: economic costs, for example as a result of reduced production, reduced fertility, increased incidence of other diseases and increased risk of early culling; the labour costs associated with the treatment and husbandry of chronically lame animals, and the welfare costs of suffering to the individual affected cow. Lameness is un-doubtedly a major welfare problem. It is also the condition that accounts for the third largest loss of income in the dairy herd, dwarfed only by mastitis and poor fertility.

In those cows that can be treated, there is often a dramatic weight loss, milk yield falls and, in protracted cases in early lactation, fertility is affected. In addition, there will be the costs of treatment, whether on-farm labour is used or veterinary attention is sought. If antibiotics are administered milk may have to be discarded. One UK study, in which the author took part, involving over 1,100 cow years on trial, showed that on average each case of lameness, ranging from a mild digital dermatitis to a more severe sole ulcer, led to a yield reduction of almost 400 litres per lactation, and that the start of this reduced yield could be detected for up to four months prior to the lameness being first noticed (49).^* This strongly suggests that there are changes occurring in the foot well before lame-ness becomes apparent.

The same study showed that cows which go lame are generally the higher yielders in the group, and many other papers have shown a similar relationship between higher yields and lameness. A second study by the same group of authors (3) involving 1,824 lame cows, showed a yield decrease of 570 litres for a case of lameness caused by a sole ulcer and 370 litres for a case of white line lameness. Although it was not significant, the study also found that for each case of digital dermatitis treated, yield increased by 1.0 litres.

One of the most dramatic changes seen in lame cows is undoubtedly weight loss. It is surprising how many cows continue to milk, especially in the early stages of lameness, although weight loss can be dramatic. Farmers who have out-ofparlour computer feeders have often commented that reduced concentrate intake is seen some twenty-four hours before lameness is noticed. As discussed in later sections of this book, perversely as cows lose weight they become susceptible to sole bruising and increased lameness.

In a study (52, 103) of grazing animals, it was shown that lame cows spent longer lying down and less time grazing, and even when they did graze, bite rates were lower. However, a second study showed that although lame cows spent longer lying in cubicles, when they did eat, their intake at each meal was greater than in non-lame cows (73). Lame cows lose the ability to defend themselves and get pushed further down the scale of ‘social dominance’. They tend to be last to access the food, later entering the milking parlour (which means that they stand for longer at each milking) and more restless in the parlour than non-lame animals.

Not surprisingly, fertility is also affected. A detailed study of 427 cases of lameness in seventeen dairy herds in Somerset (33) showed that affected cows took between 0 and 40 days (an average of 14 days) longer to get back in calf, depending on the stage of lactation when the cow was first affected, the cause of the lameness and its severity. Some cows did not recover, of course, and hence culling rates were increased. Yields were depressed by between 1 and 20 per cent, depending on the severity of the lameness.

A late-lactation cow with a mild case of foul in the foot or digital dermatitis is easily treated and suffers virtually no adverse effects. A severe, penetrating ulcer with secondary infection of the navicular bursa or pedal joint can lead to the loss of the cow and obviously a substantial loss of income.

Assessing Lameness by Locomotion or Mobility Scoring

At one stage we thought it was obvious when a cow was lame. She was holding her leg and not taking weight. It is now recognised that lameness can be detected at a much earlier stage than this by watching her as she walks. This is known as ‘locomotion scoring’, or ‘mobility scoring’, and if the whole herd is mobility scored it gives an indication of the overall level of foot problems in the herd. Several systems of locomotion/mobility scoring have been proposed. One of the first was by Sprecher (92) who used

1. Sound. Cow stands and walks with her back level and takes long strides.
2. Slightly lame. Stands with level back but walks with arched back and takes shorter strides. Does not favour any obvious limb.
3. Moderate lameness. Stands and walks with arched back. Moves with short strides; reduced weight bearing can be detected on affected leg. Head drops when weight is taken on affected leg.
4. Severe lameness. Back arched when standing and walking, with obvious reduced weight bearing on affected limb. Cow moves slowly, often making frequent stops, and may show secondary signs of pain such as weight loss, teeth grinding and excess salivation.
5. Extreme. Back arched, unable to move. Does not take weight on the affected leg.

More recently DairyCo UK (106) have proposed a modified four-point mobility score, namely:

• 0. Walking with a flat back and long and even stride length.
• 1. Walking with shorter or uneven strides but unable to see which leg is being favoured.
• 2. Back arched and affected limb is identifiable limb, i.e. limping.
• 3. More severely lame; unable to keep up with the herd average or human walking speed.

The Incidence and Prevalence of Lameness

Incidence is the number of cases recorded over a period of time, e.g. one year.

For example, quoted figures for well-recorded herds vary between 4 and 55 per cent of cows affected each year (91), with an average case incidence of around 50 cases per 100 cows per year. ‘One case’ is defined as one foot affected once, so if a cow is lame in, for example, both hind feet, then this is two cases of lameness. Part of this wide variation arises from the source of the survey material. If veterinary practice records are used, then a lower incidence is obtained (4.7–5.5 per cent) (44, 90). However, taking combined veterinary and farm treatments gives an annual incidence of approximately 25 per cent of cows in the national herd being treated for lameness each year (5, 104). Considerably more cows than this need corrective hoof-trimming, and this incidence has persisted over several years, from the late eighties and early nineties (61) until well into the 21st century.

Prevalence is the number of cows found to be lame at any one visit, e.g. when the whole herd is mobility scored, and is becoming a more frequently used measure to assess overall herd performance. For example in a 2007 study of 205 UK dairy farms, Barker (107) found a mean prevalence of lameness (mobility scores 2 + 3) of 36.8 per cent, with a range of 0 to 79.2 per cent. Similarly Huxley (108) reported a 24 per cent lameness prevalence in organic herds and Haskell (109) a 15 per cent prevalence in grazing herds and 39 per cent in housed herds.

One might question why, after so many years of research, the incidence of lameness has not decreased. There is no one single answer, but it is likely to be because many of the factors that predispose to lameness (increased yields, high concentrate feeding, changing from straw yards to cubicles/freestalls) have become more of a feature of the dairy industry. In addition, digital dermatitis, first reported in Italy in 1972, then in the UK in 1985, has now become widespread, and in its variety of forms probably now accounts for up to 30 per cent of all lame cows. For example, in one UK study (22) where the overall incidence of recorded lameness was almost 70 cases/100 per year, the incidence of sole ulcers, white line lesions and digital dermatitis were all equal at approximately 12 cases/100 per year, with ‘foul’ being slightly lower at 7 cases/100 cows per year.

In another study (3) involving 50 UK herds monitored for three years, 35 per cent of cows went lame, and the case incidence was 6.8 cases/100 cows per year for sole ulcers, 5.4 for white line disease, 6.3 for digital dermatitis (DD) and 5.6 cases/100 per year for ‘other’ lesions. Since 2007/2008 DD has become even more important due to its involvement with non-healing hoof lesions, many of which require amputation. This is discussed in more detail in Chapter Five.

A survey published in 1982 (90) showed that leg disorders accounted for only 12 per cent of the total number of cases of lameness (mainly calving injuries), and hence 88 per cent of lameness was associated with the foot. Of these, the majority (86 per cent) were in the hind feet, with the outer claw (85 per cent) being the most likely to be affected. As front feet are much more difficult to restrain and treat, perhaps it is just as well that they are not so commonly involved!

Quantifying the Financial Costs of Lameness

The losses of yield – approximately 400 litres from each lame cow – and the effects of lameness on fertility and culling were given earlier in this section. In an assessment of the total losses associated with lameness, Esslemont (45) estim ated that lameness cost the dairy industry in England and Wales £90 million per year (1990 values) or £31.50 for every cow in your herd! He also estimated that the average cost of lameness in a typically affected cow was £227–£297 for a sole ulcer, £139–£153 for digital disease (white line infection, sole abscess or sole penetration), and £24–£58 for interdigital disease (foul, dermatitis, skin hyperplasia, etc.), the major proportion of these costs arising from the effects of lameness in early lactation on subsequent fertility and culling rates.

These figures do not take into account the welfare of the cow, or the additional work and frustration caused to the herdsman in the treatment, husbandry and management of such cows. Since that time, the costs and profitability of the dairy industry have changed, but it is likely that the cost of lameness has remained the same.

About this Book

So, what can be done about this expensive condition?

The objectives of this book are:

• to give the reader a better understanding of the anatomy of the foot and the importance of its weight-bearing surfaces
• to see what happens during overgrowth and how this results in the foot becoming destabilised; to discuss and demonstrate the principles of foot-trimming
• to describe and illustrate the various disorders of the foot that lead to lameness
• to discuss a basic approach to treatment for each condition
• to discuss the various causes of lameness and aspects of lameness prevention.

Note

* Bracketed numbers refer to references, which are found on pages 152–157.

Table of contents

• Cover
• Half Title
• Title
• Copyright
• Contents
• Forewords
• Preface
• Acknowledgements
• Dedication
• CHAPTER ONE THE INCIDENCE AND COSTS OF LAMENESS
• CHAPTER TWO FOOT STRUCTURE, FUNCTION AND INFLAMMATION (CORIOSIS/LAMINITIS)
• CHAPTER THREE WEIGHT-BEARING SURFACES AND HOOF OVERGROWTH
• CHAPTER FOUR HOOF-TRIMMING
• CHAPTER FIVE COMMON DISEASES OF THE FOOT AND TREATMENTS
• CHAPTER SIX THE CAUSES AND PREVENTION OF LAMENESS
• APPENDIX A summary of factors causing lameness
• References and further reading
• Index