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2 HERD EXAMINATION FOR LAMENESS-GUIDELINES FOR THE PRACTITIONER Uri Bargai Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, 76100, Israel Introduction Lameness in dairy cattle is associated with serious direct and indirect economical losses. Direct losses include reduced milk production that can be up to 20%, veterinary fees, medicines, extra labor and loss of body weight. Indirect losses include delayed or silent heat, increased average open days and early culling. The prevalence of lameness vary, but can reach 25% and higher values. In the U.K, values up to 60% of lame cows annually were reported. Any prevalence higher than 5% annually indicate a herd lameness problem. Lameness in cattle is a multi factorial disease. Factors reported to contribute to the development of lameness include nutrition, environment, infection, genetics and human and animal behavior. The lameness of the cow which results from the effects of these factors finds it expression in a musculoskeletal lesion. Studies of hundreds of lame cows have shown that 90% of these lesions are located on the lower feet of the cows, and of those - the majority are sequelae of laminitis. Sequelae of laminitis include white line and solar hemorrhages, white line separation, abscesses in the white line and septic arthritis due to extension of white line abscess Investigation of a herd problem of lameness involves investigation into all factors operating in a dairy herd maintenances. The following are suggested guidelines for such an examination done by the practitioner who is responsible for the health of the herd. Guidelines: The examination consists of 2 phases: 1) Preliminary phase: The farm manager or the herd owner should complete a questionnaire about the housing, flooring, nutrition, lactating groups, division of the lameness cases among the different lactation groups, lameness cases treated by the owner or the staff, and other management factors operating in the herd. This questionnaire will enable the practitioner to learn if the lameness is diffusely spread or focal, and whether there is any connection of the lameness cases with a certain type of housing or flooring. The preliminary phase also includes arranging with the hoof trimmer of the herd to join the schedule farm visit. 318

3 Phase 2, the farm visit: The farm visit include 5 stages: 1) Clinical examination of 5-10 new cases of lameness which appeared during the last few days. The examination should be carried out in a trimming box, where foot lifting is possible. The purpose of this stage is to see in person the lameness cases and not to rely on the diagnoses or medical information provided by the herd director or herdsman who may group different lesion under the same diagnosis such as Foot Rot. Such relayed diagnosis can be misleading. Proper definition of the type of the lameness is essential. 2) Hoof controlled trimming of 5-10% of cows selected at random from each of the milking groups in the herd. The trimming should be done by the regular hoof trimmer. Any lesion encountered should be recorded on a separate sheet for each cow. The purpose of this random cow trimming is to look for evidence of laminitis in the herd. White line hemorrhages if seen in the trimming, indicate an episode of subclinical laminitis which occurred 6-10 weeks ago, the time which it takes for the free blood at the laminitis site to infiltrate to the solar surface of the hoof. Positive findings indicate nutritional mistake made 6-10 weeks ago. This mistake should be investigated and defined during the investigation. Laminitis, as was already mentioned, is the most important etiological factor in cattle lameness. In addition to hemorrhages, also white line separation indicate sub clinical laminitis, but many months ago. Such separation serve as portal of entry to bacteria and result in abscesses. By repeating such random trimming in each of the at-risk groups, the practitioner is able to locate the problem, and concentrate more on the problematic section of the herd in the investigation to identify the exact risk factor operating in this herd. 3) Examination of the environment. The housing and flooring of each of the groups should be inspected, to detect any substandard floors which may cause solar hemorrhages and sole bruising. Cracked deteriorating concrete floors in the passages or milking parlor are often seen as the cause of solar abscesses. Slippery floors may prove to be the cause of tendons over-stretching or spraining fetlock joints. Excessive grooving of the parlor holding pen floor to prevent skidding may be the cause for solar bruising, infections and lameness. 4) Examination of the feedstuffs. Such examination may resolve questions about the role of the feedstuffs in creating the episodes of the subclinical. Laminitis encountered during the trimming. Physical examination of the silage should include examining the ph of the silage and the fiber length, two factors in the silage responsible for the rumination and for rumen ph. Those factors should be according to the N.R.C. recommendations. 5) Discussion in the office. The final stage of the farm visit takes place in the office, and is very crucial because it integrate the findings during the visit, the practitioner should prepare 319

4 a list of conclusions and recommendation for changes necessary to eliminate the lameness problem of the herd. All the stages of the farm visit can be accomplished in one day, providing that the preliminary phase is carried through. Being able to complete the entire examination on the same day is an important factor for both the bovine dairy practitioner and the farm director. Dairy practitioners are always under pressure of time, and being able to complete the examination in one day is of great value. The model of guidelines suggested here was practiced by the author for several years in Israel on Kibbutz dairy herds sized up to 600 cows per herd and proven to be very effective and efficient. 320

5 PROSPECTIVE LAMENESS STUDY OF CATTLE TREATED AT A UNIVERSITY HOSPITAL: PRELIMINARY DATA E.B.Belknap, 1 A. Heath, C. Navarre, F. DeGraves, G. Riddell, R. Eddelman College of Veterinary Medicine, Auburn University Introduction Lameness is important problem for the cattle industry. Along with reproductive problems and mastitis, lameness is one of the top three reasons for culling of cattle. While the etiologies of lameness may reflect anything from a dislocated hip to a fractured distal phalanx, approximately 90% of the lesions are localized to the foot. Costs of lameness have been reported to range from $300 to $350/cow. The aim of this study was to assimilate data on the lameness cases presented to the Auburn University Large Animal Clinic (AULAC) and to characterize the different types of lameness, as well as severity of lesions, different treatments, response to treatments, costs, and return to productivity in the herd. Cases presented to this hospital are either referred by a veterinarian or use the AULAC for their primary care. Data from the first year of this 5-year study will be presented. Materials and Methods Of 1024 bovine cases seen at AULAC from 8/01/00 to 7/31/01, 274 presented due to lameness or foot problems. Data were collected on the following parameters: diagnosis of lameness/lesion, duration of lameness, prior treatments, limb and portion of claw affected, severity of lameness, severity of lesion, and treatments (Figures 1 & 2). Each animal was assigned a specific diagnosis, but some animals had more than one. Additional lesions were recorded. At six months post discharge from AULAC, a card was mailed to each owner to determine the disposition of the lameness and the animal. Results Entries were made for 361 primary lesions/diagnosis. Listed in decreasing order for observed lesions were: hoof overgrowth, papillomatous digital dermatitis, subsolar abscess, corkscrew claw, sole ulcer, interdigital fibroma, and interdigital dermatitis. Normal hoof overgrowth and corkscrew claw accounted for the greatest number of additional lesions observed. The greatest mean for duration of hospitalization were for septic arthritis (mean 18.8 days) and osteomyelitis/ osteitis (16.9 days) cases. Discussion It would appear that our data collection system for lameness in cattle is an acceptable method for assimilating data. While we realize that our caseload a is specific for AULAC, the information obtained will be helpful when assessing the prognosis and economics of treating specific conditions/lesions associated with bovine lameness. As this data is from the first year of this study, follow-up on these cases is limited at this time. 1 Contact at: McAdory Hall, College of Veterinary Medicine, Auburn, AL USA; ; Fax: ; belkneb@vetmed.auburn.edu 321

6 References 1. Guard C. The cost of lameness and value of routine hoof care. Proc. Hoof Health Conference, Batavia, NY,

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9 LAMENESS PREVALENCE AND THE EFFECT OF HOUSING ON 30 WISCONSIN DAIRY HERDS Nigel B. Cook, BVSc, Cert CHP DBR, MRCVS 1 University of Wisconsin-Madison, School of Veterinary Medicine Introduction There is a paucity of data on the prevalence of lameness in dairy cows in North American herds. A study by Wells et al., (1993) conducted on 17 predominantly stanchion housed dairy herds in the Mid-west, with a mean herd size of 50 cows, demonstrated a prevalence of 13.7 % in the summer and 16.7 % in the spring. In contrast, Clarkson et al (1996), in the UK, found a higher mean prevalence of lameness of 20.6 % on 37 free-stall housed dairy farms. The range was from 2% to 53.9% and prevalence was higher in the winter at 25% than the summer at 18.6%. With more and more herds expanding and moving to free-stall housing systems in the Mid-West, a review of lameness prevalence in different housing systems, utilizing different stall surfaces, was warranted. The objectives of this study were therefore to determine the prevalence of lameness on a range of well managed Wisconsin dairy farms using a simple locomotion scoring system, incorporating the observations made by Sprecher et al., (1997). Materials and Methods Thirty DHIA recorded Wisconsin dairy farms were selected to include herds with a Rolling Herd Average milk yield greater than 19,000 lbs. 15 stanchion/tie-stall herds and 15 freestall herds, utilizing sand, concrete or rubber mat and mattress stall bases, were visited twice, once in the spring/summer and once in winter, between April 2000 and April All milking cows were locomotion scored on a scale of 1 (normal) to 4 (severely lame) and the prevalence of lameness (Defined as the percent of the cows scoring 3 or 4) calculated for each visit. On free-stall herds, a Cow Comfort Index (CCI) was measured one hour before milking (Defined as the proportion of cows in stalls, which were standing). On all herds, stall details and base type (concrete or rubber mat, mattress or sand) were recorded. The data were entered into Excel and analyzed using one way analysis of variance and the PROC MIXED procedure of SAS (SAS Inst., Inc., Cary, NC). Results and Conclusions Mean herd size was 140 cows (free-stall 175 cows, stanchion/tie 67 cows) and mean rolling herd average milk yield was 23,060 lbs (range 19,009 to 29,414 lbs). Eight herds used sand bases (4 depth or greater), ten herds used a mattress and twelve herds used either concrete or a rubber mat as a stall base. 1 Contact at: 2015 Linden Drive West, Madison, WI, ; ; nbcook@facstaff.wisc.edu 325

10 Mean lameness prevalence was higher during the winter than during the spring/summer (24.8% winter and 21.8% spring/summer), with a range from 7.9% to 51.9%. The difference was only significant for the free-stall herds (p<0.05) where passageway manure management during freezing weather conditions may have been an important factor. Lameness prevalence was higher in free-stall herds than stanchion/tie stall herds in spring/ summer and winter, but these differences were not significant. Choice of stall base was an important factor influencing lameness prevalence (Table 1). As there was no significant difference between prevalence of lameness on herds using concrete or mats and mattress stall bases, the data from these herds were analyzed as one group referred to as hard. Sand stall base herds had a mean lameness prevalence of 13.6% in the spring/summer and 16.9% in the winter. In contrast, herds with hard stall bases averaged 24.2% and 27.2% lame. These differences were significant at p<.05. Mean CCI in the free-stall herds was 21.4% in the spring/summer and 20.0% in the winter. Sand stall base herds had a significantly lower CCI at 15% compared with 25% in hard stall base herds (p<.05) in the spring/summer. These data confirm that lameness is a significant problem in Wisconsin dairy herds. The recorded level is higher than that reported by Wells et al., (1993), but within the range of the more recent UK study by Clarkson et al., (1996), suggesting that the problem may be increasing. Analysis of the data in this study, by stall base, demonstrates that choices in housing design and bedding may have an impact on the degree of lameness on a farm. Leonard et al., (1994) found that stall occupancy rates were less in one type of stall design with no bedding than another bedded with a rubber mat, and that claw health was better after calving in the group with the higher lying score. Deep sand stall bases appear to provide a greater degree of cow comfort than other types of stall base, potentially increasing lying times and providing a significant reduction in lameness prevalence. References 1. Clarkson M.J, Downham D.Y, Faull W.B, Hughes J.W, Manson F.J, Merritt J.B, Murray R.D,Russell W.B, Sutherst J.E, Ward W.R. Incidence and prevalence of lameness in dairy cattle. Vet Rec 138: , Leonard F.C, O Connell J. and O Farrell K. Effect of different housing conditions on behaviour and foot lesions in Friesian heifers. Vet Rec 134: , Sprecher D.J, Hostetler D.E. and Kaneene J.B. A Lameness scoring system that uses posture and gait to predict dairy cattle reproductive performance. Theriogenology 47: , Wells S.J, Trent A.M, Marsh W.E and Robinson R.A. Prevalence and severity of lameness in lactating dairy cows in a sample of Minnesota and Wisconsin herds. JAVMA 202:78 82,

11 Table 1. Least Square Mean (Standard Error) Lameness Prevalence in 8 herds using sand base stalls compared with 22 herds using concrete, rubber mat or mattress (Hard) base stalls in spring/summer and winter. Lameness Prevalence Sand Base Herds Hard Base Herds Spring/Summer 13.6 (3.2)* 24.2 (2.0)* Winter 16.9 (4.0)* 27.2 (2.3)* *Statistical significance across rows at p<0.05 one way ANOVA 327

12 A MATHEMATICAL MODEL FOR THE PATHOGENESIS OF DIGITAL DERMATITIS IN CATTLE D. Döpfer 1 Institute of Infectious Diseases and Immunology, Department of Parasitology and Tropical Veterinary Medicine, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL Utrecht, The Netherlands The incidence of digital dermatitis (DD) remains high and the aetiology of this multifactorial infectious claw disease has not been clarified completely since the first description in 1974 by Cheli and Mortellaro. Mathematical models on the other hand, are becoming more common in veterinary epidemiology. They are being used to discuss complex dynamics of disease and derived from many disciplines, where complex interactions are observed or postulated to exist. A deterministic mathematical model is presented for the interaction between host and microorganisms during the pathogenesis of bovine digital dermatitis. This approach is an attempt to extrapolate cellular dynamics during the host-pathogen interaction to describe the different courses of disease observed in the individual cow. A severe and a mild course of disease are simulated during an endemic situation. A compartmental model with intact and disrupted barriers is developed to simulate the contact between phagocytes, keratinocytes and proteolytic bacteria in bovine digital skin. This contact results in an inflammatory reaction, which produces ulcerations. Possibilities of fitting the model to real-world data will be explored and the usefulness of this approach will be discussed. 1 Contact at: Institute of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Department of Parasitology and Tropical Veterinary Medicine, Utrecht University, Utrecht 3584 CL, The Netherlands; Ph (H): , (W): ; Fax: ; D.Dopfer@vet.uu.nl 328

13 MONITORING CLAW DISEASES IN THE NORWEGIAN CATTLE POPULATION T. Fjeldaas, 1 K. Plym Forshell 2 and O. Østerås 1, 2 ¹Norwegian School of Veterinary Science, P.O. Box 8146 Dep.-N-0033 Oslo, Norway ² TINE Norwegian Dairies BA, P.O. Box 58, N-1431 Ås, Norway Introduction As 7% of the barns in Norway are cubicles, approximately 90% of the cows are housed in barns with tie stalls while 10% are housed in cubicle systems. For 25 years individual health records have been used to assess the status of production diseases in the Norwegian dairy cow population. Veterinarians record every single diagnosis and treatment. Digested data are returned to the farmer on a regular basis together with milk recording figures. The system is however not sufficient for monitoring claw diseases. Veterinarians too seldom diagnose such diseases, as restraining equipment is often needed, but seldom available. Furthermore, many claw diseases are often chronic disorders which farmers may pay little attention to. Professional hooftrimmers make regular visits to many farms, but their treatments to now have not been recorded. Available statistics from the health card system report an incidence rate of only 1.5 cases of claw diseases per 100 cow-years (365 days at risk). This is probably too low according to the real incidence rate. In order to develop a reliable recording system for claw diseases a preliminary study was carried out during the indoor season 2000/2001. The main precondition in the study was that claw diseases would be diagnosed and recorded by professional hooftrimmers during their routine work in cattle herds. Materials and Methods A recording protocol for claw diseases was created in accordance to the international ABC foot score system 2. Seven experienced hooftrimmers were taught how to diagnose the most common claw diseases and use the recording protocol. The initial education in diagnosis and recording of claw diseases for the hooftrimmers was completed in 4 days. The skills in hooftrimming and ability to diagnose claw diseases were evaluated. The primary aim of the study was to evaluate the recording system in approximately 60 herds, evenly distributed in three counties. Records are available from 52 of the herds in which altogether 696 cows/heifers got their claws trimmed. Ten of the herds (161 animals) were housed in loose housing systems; 9 of them (151 animals) in cubicle systems and one herd (10 animals) in a straw yard system (in this study grouped together with the cubicle system). Forty-one of the herds (525 animals) were housed in barns with tie stalls. Sixteen of these herds (234 animals) were tied in stalls with rubber mats, 20 of them (244 animals) were tied in stalls with concrete floor and 5 of the herds (47 animals) were tied in stalls with other types of floor. One-way ANOVA was used to compare groups with regards to prevalences. Differences were considered significant with p-values less or equal to 5%. Results Disease prevalences: Altogether 10.9% of the animals had remarks as to health of the fore claws; 2.7% had heel horn erosions; 0.6% had sole ulcers; 7.9% had hemorrhages of the 1 Contact at: Norwegian School of Veterinary Science, P.O. Box 8146 Dep.-N-0033 Oslo, Norway; Tel: ; Fax: ; terje.fjeldaas@veths.no 329

14 sole/white line; and 0.6% of the animals had digital/interdigital dermatitis. Fore limb lameness was recorded in 0.9 % of the animals % of the animals had remarks as to health of the hind claws; 10.3% had heel horn erosions; 4% had sole ulcers; 20.1% had hemorrhages of the sole/white line; and 4.5% of the animals had digital/interdigital dermatitis. Hind limb lameness was recorded in 5.0 % of the animals. Housing: There were significant differences between the prevalences of claw lesions in different housing systems. Cubicle systems appeared to provide an increased risk for heel horn erosions and hemorrhages of the sole /white line compared to all kinds of tie stalls (Figure 1). Concerning digital dermatitis and sole ulcer there were minor differences between cubicle systems and tie stalls with concrete floor. However, tie stalls with rubber mats appeared to be the best housing alternative to decrease the prevalences of all claw lesions recorded in this study. Hooftrimmers: In order to evaluate the reliability of this recording system with its involvement of many hooftrimmers the prevalences of hind claw lesions recorded by each hooftrimmer were estimated and separated as to housing of the herds. For these prevalences we found pronounced differences between the hooftrimmers. However, the relative risks for increased hind claw remarks in herds housed in cubicle systems compared to those housed in barns with tie stalls were consistent for the hooftrimmers, ranged between 1.4 and 5.6 for those who had made recordings in both kinds of housing systems. The relative risks for increased hind claw remarks in herds tied in stalls with concrete floor compared to those tied in stalls with rubber mats were also consistent for the hooftrimmers, ranged between 2.2 and 5.4 when calculations were possible. Discussion The results indicate that cubicles provide an increased risk for heel horn erosions and hemorrhages of the sole/white line compared to tie stalls. Furthermore, tie stalls with rubber mats appear to represent a housing system that decreases the prevalences of the most frequent claw diseases in Norway. Both these findings are in accordance with observations made by Bergsten 1. This preliminary study is, however, based on a too low number of animals to be more than indications of the real Norwegian prevalence rate. In addition there has been no random sampling of the material. In most of these herds regular hooftrimming has been routine management for many years. Most of the monitoring has been done in the fall season from October to December. The prevalence rates of claw diseases are expected to be higher if the recordings are made during springtime. Conclusions The recording differences between the hooftrimmers can to some extent be explained by major differences according to housing and management systems, and the consistence of relative risks indicates that this recording system can be used in the future. However, differences in the hooftrimmers ability to make reliable records cannot be ignored. Thus, the education of the hooftrimmers and the evaluation of their recording of claw disorders have to be improved. These considerations will be applied in the next Norwegian study of claw diseases that will be completed in 4 years. An important aim is that recording of claw 330

15 diseases will be included in the hooftrimmers routine work, and that these recordings will provide a reliable system for monitoring claw diseases in the Norwegian cattle population. References 1. Bergsten C: Effects of conformation and management system on hoof and leg diseases and lameness in dairy cows. In: Anderson DE :The veterinary clinics of North America. Food animal practice. W.B. Saunders Company, pp. 1-23, Doepfer D, et al: Workshop report about the documentation of claw diseases. In: Mortellaro CM, et al, eds. Proceedings of the III International Conference on Bovine Lameness, Parma, Italy, pp. 9-16,

16 60 52, Prevalence % ,8 34,8 15,6 22,3 23,8 34,8 11, Cubicles D 5,6 E B/H 4,3 U T Tie stalls D 3,8 6,1 E B/H U 4,0 T Tie rubber D 0,4 0,0 5,1 E B/H U T Tie concrete 2,1 7,3 D 6,1 E B/H U 4,9 T Figure 1: Prevalence of bovine hind claw lesions as to housing; Cubicle housing, Tie stalls (all), Tie stalls with rubber mats, Tie stalls with concrete floor. D: Digital/ interdigital dermatitis, E: Heel horn erosion, B/H: Hemorrhages of the white line /sole, U: Sole ulcer, T: Total hind claw remarks. 332

17 LAMENESS AND MILK PRODUCTION IN DAIRY COWS Jorge Hernandez, 1 Jan K Shearer, Dan W. Webb From the Department of Large Animal Clinical Sciences, College of Veterinary Medicine (Hernandez, Shearer) and the Department of Animal Sciences, Institute of Food and Agricultural Sciences (Webb), University of Florida, Gainesville, FL, USA A study is in progress to examine the relationship between lameness and milk production in Florida dairy cows. A total of 787 cows that calved from 1997 to 1998 were initially considered for inclusion in the study. Cows affected with lameness were classified into 1 of 3 groups on the basis of types of disease or lesions observed, including papillomatous digital dermatitis, foot rot, or claw lesions. Clinical diagnosis of lameness was made by farm personnel and confirmed by the same attending veterinarian or herd s hoof trimmer during the study period. Cows affected with lameness had an arched-back posture while standing and walking and an abnormal gait. Cows nonaffected with lameness were classified as healthy. For each cow, the following data were collected: parity (1,2,3,4+), calving date, calving season (Jan-Mar; Apr-Jun; Jul-Sep; Oct-Dec), dystocia (yes, no), retained placenta (yes, no) and metritis (yes, no), clinical ketosis (yes, no), and clinical mastitis (yes, no). From Dairy Herd Improvement Association records, milk yield data (305-day mature equivalent milk yield) were collected at end of lactation or when the cow left the herd. Multiple regression analysis will be performed in order to assess the relationship between lameness and milk production while simultaneously adjusting for variables related to milk production. Two hundred and forty-four (33%) cows were affected with lameness. Most lame cows had claw lesions (64%), followed by papillomatous digital dermatitis (30%) or foot rot (6%). In the univariable analysis, milk production in lame cows with foot rot (16,024 ± 1,232) was significantly lower, compared to healthy cows (P < 0.01). Further results of multiple regression modeling will be presented. 333

18 CLAW MONITORING IN DAIRY HERDS IN THE NETHERLANDS. A VISION IN THE FUTURE M. Holzhauer, DVM. 1 Animal Health Service, Deventer, The Netherlands Abstract: Lameness is considered as the third, economically most important, disorder on dairy farms in the Netherlands after mastitis and fertility-problems. Each year an estimated 15-40% of the milking cows will be treated for lameness by a farmer, claw-trimmer or veterinarian. This is in addition to the routine trimming two times a year by the claw-trimmer. It is clear that the costs of this disorder are enormous. There are economic consequences because of secondary problems and decreasing the durability of cows life 1. To give the farmer more insight in his management, a number of planners are developed in the Netherlands. These planners are a tool for the farmer in order to establish appointments for treatment or prevention of some diseases and targets for a next period. It stimulates good discipline of all of the participants and includes moments of evaluation. The result of the use of the mastitisplanner 4 is used as an approach to claw education and set up a claw-monitoring program. In the Netherlands the normal hoof-care is mostly a claw-trimmers job. The practitioners are only consulted for complex cases, for medical advises, group diagnosis and for their knowledge of risk factors. Most of the trimmers are well educated in the Dutch claw-trimming method and are good equipped for doing the routine work on dairy farms. A permanent system of education has been developed for the hoof-trimmers and the veterinarians and will include e.g. in a permanent training in good diagnosing and a protocollair therapeutically approach of specific claw-problems. In addition to the education there is a trail to implement a system of registration, as a system of monitoring on the farm and on sectors level also. In this way the executive committee of farming organization has insight in the main claw-problems, normal values and can give priority to research. Introduction In the Netherlands treatment of lame cows is for about decades no longer a subject of the veterinarians, but more and more a claw trimmers job. They are better equipped and have a better routine in normal functional claw trimming. The disadvantage of this development is that the knowledge of most of the trimmers is based on a course of about two weeks, routine of trimming and information picked up from agricultural magazines. There is not a system of systematical training in courses or other forms of periodical training. The knowledge of the anatomy and the different infectious and non-infectious diseases, with the different backgrounds of etiology and risk factors is a part of the veterinarian education. This is repeated and refreshed on post-graduated courses. These courses are obliged for vets, who wants to work as a bovine-practitioner, and permitted to do herd health and production management (HH & PM) service. The executive committee of the Dutch claw trimmer organization has agreed with a same program of permanent education for their members 1 Contact at: Animal Health Service, P.O. Box 9, 7400 AC Deventer, the Netherlands; Phone: ; Fax: ; m.holzhauer@gdvdieren.nl 334

19 also. In the first period based on voluntarily, but on command of the customers in the near future a farmer will be obliged to have his cows trimmed by a well-educated claw-trimmer. A definition of HH & PM service is: a complex of integrated veterinary and animal husbandry activities, centered around regularly planned farm visits, and based on a protocol approach to operational farm management functions 2. The principles of this system are based on gathering information, analyzing the problems, making diagnosis, evaluation and interpretation, formulating targets and giving a follow up. In the Netherlands this is called monitoring on farm level. In this system every time the veterinarian manage in cooperation with the farmer herd-health and preset targets are being evaluated together (see figure 1). Figure 1. Herd health and production management protocol for replacement rearing 2. In relation to the nowadays structure of claw-health management in the Netherlands: most of the first diagnosis are made by the trimmer, the treatment is carried out by the trimmer, nothing is registered systematically and the farmer will be advised on impressions of the trimmer. In this contribution a vision for improving the system of claw management will be explained and results of the use of the mastitis planner will be discussed as an example of our vision of the goal of the claw-planner. To realize the system of claw management in the Netherlands a project will start in January 2002 which has one aim: Improving the claw health on dairy farms. 335

20 Tools to realize are: 1. Introduction of the claw-planner to the target groups. 2. Upgrading of the claw-planner (protocol outlined achievement). 3. Monitoring: analyses of main problems on farm and sector-level. The general interest of improving claw health is vested on the basis of: a. Limiting of the direct damage (farmer/sector). b. The decrease of the use of medicines. c. The animal welfare. d. The image of the sector. An instrument is developed for the individual farmer to work with, called the claw-planner. The Claw-planner. Definition of a Claw-planner: A Claw-planner is a tool to get information about the claw healthcondition in relation to the daily events on a dairy farm, under condition that the farmer registers any event that takes place on his farm. This planner has been developed after a good received introduction of other planners like the mastitis-planner and the fertility-planner. All planners are now being integrated and it is to be expected that in the near future an integrated planner will be available for the farmers and his advisors, like e.g. the veterinarians and the claw trimmers. The introduction and the information for the farmers will take place in an integrated planner. For a good function of the planner the farmer has not only to register all the information of the claw-trimming session but also the daily events. These results have to be interpreted by a veterinarian, who based his management-advise on this information. This information has to be combined with the farmer targets and other things like: - Date of calving. - System of calving management. - Incidence of illness of the cows, like mastitis, retained placentas, endometritis, dislocation of abomasum and so on. - Ration and system of feeding and steaming up. - Housing system (slatted floor with or without with shovel, ventilation, management of housing pregnant heifers). - Hygiene and system of using footbath, and so on. Reference values: The reference value must be comparable with values, as in the Netherlands well known from results from the milk-production measurements. The setting up of reference values is the next phase after introduction and implementation of the planner for the target group. The result of that part is the possibility of comparing the score of the own live stock with comparable stocks. The reference values will be estimated for the parts of the main scores of the claw-planner next year. 336

21 The farms score (positive or negative) of the reference value is for advisors a guide for managing. It enables the veterinarian, the farmer and other advisors to monitor claw health (during HH & PM) and he/she can get insight in the effects of management measures. It also gives the farmer and his advisors the possibility to score a farm for claw health. Reference values enlarge the effect of the planner in practice. Welfare: The claw score, compared with reference values, makes it possible to transfer the score to an objective opinion about welfare for that farm. In the Netherlands knowledge about claw-problems in relation to welfare is developed among others in the National Research Institute in Lelystad. In the near future it will be translated for a practical use in the field: developing a welfare score based on a score for legs and claws. Sector: policy and research. On sectors level aggregated results can give information and insight in the way claw health (e.g. in relation to different housing systems or breeding programs) is developing. Beside that it can give information on what are the main problems in the sector and information to breeding organizations about possible genetically related claw-problems of bulls used in breeding programs. Policy can be made and research can be initiated to causes or intervention. For realizing the plan, a program is made, to realize our goal. Phase 1: Introduction, education and transfer of practical knowledge to all persons concerned. Phase 2: Improving the practical possibilities of the claw planner (reference values). Phase 3: Monitoring of claw health. Phase 4: Welfare scale based on claw health. In 2002 phase 1 will be exercised by theoretical and practical training veterinarian s en clawtrimmers about the claw-planner and how to use in practice. A training program has to be followed in making correct diagnosis (infectious and non-infectious problems) in combination with the ABC scoring system as introduced by Bergsten in Parma 3. In the same period reference values for the different claw problems in the Netherlands will be estimated by gathering information of 1000 dairy herds by 20 well trained claw-trimmers, who visit each farm two-times a year at least for routine trimming. For good permanent monitoring in the years after the introduction each next year 100 dairy farms will be replaced by other dairy farms. The use of the mastitis-planner 4 (with the background information about the etiological factors of different aspects of clinical and subclinical mastitis and the weekly measuring of somatic cell count) have lead to more insight into udder-health problems on the different dairy farms. This also has lead to standards enforced by the customers about udder-health condition. Nowadays these customers are under certain circumstances allowed to refuse milk. It's almost sure that in the near future the same will be introduced for claw-health conditions. One of the objectives of the claw-monitoring 337

22 program on farm-level is to develop more insight in the claw-problems related to his own dairy farm and to the farm related risk factors. References 1. Stanek Ch.: Uncomplicated and complicated diseases of the deeper structures of the claws in cattle. Proc. 11 th Symp. on the disorders of the ruminant digit. Parma, Italy. (2000), Brand A., Noordhuizen J.P.T.M., Schukken Y.H. Herd Health and Production management Wageningen press. The Netherlands. 3. Bergsten C. Descriptive nomenclature and scoring of foot lesions at hoof trimming, workshop report part II. Proc. 11 th Symp. on the disorders of the ruminant digit. Parma, Italy. (2000), Hogeveen H., Lam T.J.G.M., Grijsen E.G., Sampimon, OC. Mastitis management using a monitoring system based on somatic cell count. Proc. 48 th Annual meeting of the European Association for Animal Production. Vienna, Austria. 338

23 RELATIONSHIP BETWEEN LAMENESS, OVARIAN CYSTS AND FERTILITY IN HOLSTEIN COWS Pedro Melendez, Julian Bartolome, Art Donovan College of Veterinary Medicine, University of Florida, USA Introduction Lameness occurs during the first 60 to 90 d of lactation, affecting the fertility of dairy cattle 25. Ovarian cyst is also a risk factor for infertility in dairy cows 2, 11,16. Studies designed to test the association between lameness and ovarian cysts in dairy cattle have not been reported yet. In order to explore this particular association, the objective of the following study was to establish the relationship between lameness and ovarian cyst, and fertility in Florida Holstein dairy cows. Materials and Methods The study was conducted in a Florida dairy farm milking 3000 cows 3X, with a RHA milk yield of 10,500 kg/cow/y. Cows were housed in a dry-lot/free-stall system and fed a TMR 3 times a day. Cows received bst beginning around 60 d pp and every 2 w during the entire lactation. Reproductive management consisted of a voluntary waiting period (VWP) of 80 d until first breeding. Cows were bred both using heat detection and timed artificial insemination protocols. The study consisted of analyzing historical records from cows that calved during Cows that showed claw origin lameness within the 30 d pp were cases (n= 65). Matched by parity and calving season (Oct to Mar= no summer; Apr to Sep= summer), 130 cows without lameness within 150 d of lactation were selected at random as controls. The outcome variables were conception rate at first service (CRFS, %), pregnancy rate (PR, %), calving to first service interval (CFSI, d), and incidence of ovarian cysts (OC %). CRFS and OC were analyzed by logistic regression. Odds ratios (OR) and confidence intervals 95% were calculated. Goodness-of-fit was performed using the deviance of the model. PR was analyzed by survival analysis. Survival functions and curves were developed for each group. A proportional hazard model was developed to test the association between groups and overall PR. Relative risks were reported. Results and Discussion Among the lame cows, 87.7% were diagnosed with lesions related to subclinical laminitis, 7.7% showed interdigital dermatitis and 4.6% were diagnosed with digital dermatitis. Rate of diseases related to fertility was similar between cases and controls (p > 0.05). Among the 65 lame cows and 130 control cows, 7.7% and 11.5% were bred under timed artificial insemination, respectively (P > 0.05); 30.8% and 5.4% were culled before any reproductive event, respectively (P 0.01). Therefore, 40 lame and 108 healthy cows were considered for the analysis, except for the overall PR. Although culling rate was not an outcome in this study, the rate of lame cows that left the herd before experiencing any reproductive event was as much as six times the control group (30.8 vs 5.4%, respectively). This tremendous difference has been reported in many studies where lameness has been identified as one of the greatest effect on culling in dairy herds 22,

24 Only lameness was a significant variable for both CRFS and incidence of OC (P 0.05). When OC was inc luded in the model without lameness as predictor of CRFS, it was a significant variable. However, when lameness was included in the model, OC was not significant. This indicated a multicollinearity relation between ovarian cyst and lameness status. The effect of OC was because the cows with OC were more likely to also be lame. Therefore, for CRFS we included only lameness in the model. Then, lame cows within 30 d pp were 2.63 times more likely to develop an OC before the first breeding than healthy cows. This is in agreement with a previous study 17, which was not designed to test this association. Because this is an observational study we cannot conclude a cause effect relationship. However there might be several mechanisms to explain our findings. Development of laminitis is linked to release of histamine and/or endotoxin from animals suffering rumen acidosis 20. Diet prepartum low in energy and a diet postpartum high in soluble carbohydrates were statistically related with a higher rate of sole hemorrhages and low quality horn 9. If hoof lesions were related to subclinical rumen acidosis, endotoxins released by the lysis of gram (-) bacteria in rumen, could play a very important role in both the pathophysiology of laminitis and the alteration of the follicula r phase and formation of ovarian cysts. Bacterial endotoxin given repeatedly during the follicular phase influenced luteal function, prevented the LH surge and induced cystic follicles in dairy cattle 4,12,21. Second, lameness is a painful and stressful process 28. Stress and pain in cattle result in high plasma levels of cathecolamines, glucocorticoids and stress-induced progesterone from the adrenal glands 18,27,29. Increase of the ACTH and/or cortisol, and progesterone slightly higher than normal levels have been related to a delay or inhibition of the GnRH and/or LH surge and the alteration of the normal follicular activity with the formation of persistent ovarian follicles 8,10,13,18,29. Third, cattle with lameness spend more time lying down with abnormal behavior patterns of eating, rumination and interaction with other animals 18,26. These animals loss more weight and experience a more noticeable negative energy balance than normal early pp dairy cows. Negative energy balance has an inhibitory effect on ovarian follicular growth and development 7. Pulses of LH and concentrations of IGF-I are decreased in cows losing weight 16. Furthermore, dominant follicles during negative energy balance needed more time and a larger size to reach estradiol levels to be able to induce the ovulation process 5. Whether or not the three hypothesized mechanism we propose are acting together is a question we cannot answer. However we think all of them are possible. Not only did lameness affect the PR, but also lame cows became pregnant later than non-lame cows. Overall, 27.1% of the cows were censored. Only 19.2% of healthy cows, but 43.0% of lame cows were censored. Lame cows were almost half as likely (RR= 0.43; CL= ) to conceive during the entire period (480 d) than non-lame cows (P 0.01). Survival curves for the risk of non-pregnancy between lame and non-lame cows were statistically different (P 0.01) (Figure 1). This might be explained because CRFS was lower for lame cows with more services per conception. The overall decreased fertility in lame cows has been documented in other studies 1, 6,14,15. Correcting for the other variables, non-lame cows were 4.22 times more likely to conceive at first service than lame cows. Either lameness or OC was associated negatively with CRFS. Cows with OC were more likely to also be lame. Lower CRFS might be that large persistent follicles release an oocyte that is less fertile than oocytes from smaller growing follicles, which might be related to persistent follicles that are exposed to high concentrations of LH and oocytes prematurely activated

25 Only calving season and OC were significant predictors of days to first service (P 0.05). However, lame cows had the same CFSI. Several studies have reported a longer CFSI for lame cows than normal cows 1,6,14,15. However in these studies CFSI was between 70 to 80 d postpartum; in our study the interval was approximately 95 d. The VWP in our farm was 80 d, which might explain why we did not find differences in CFSI. Our cows had a longer period to resume the ovarian activity than cows in other reports. In our study, cows with ovarian cysts had a longer CFSI than normal cows, correcting for the other variables. This finding was expected 2,3,13 and may be explained by a longer interval between waves of follicular growth in cystic cows than in normal cows 8,11. References 1. Barkema HW; et al. Prev Vet Med 20: , Barlett PC; et al. Prev Vet Med 4:15-33, Bartolome JA; et al. Theriogenology 53: , Battaglia DF; et al. Endocrinology 140: , Beam SW; WR Buttler. J Reprod Fertil Suppl. 54: , Collick DW; et al. Vet Rec 125: , De Vries MJ; RF Veerkamp. J Dairy Sci 83:62-69, Dobson H; et al. J Repro Fert 120: , Donovan GA; et al. Proc 35 th Annual Florida Dairy Production Conference; University of Florida , Duchens M; et al. Theriogenology 42: , Garverick HA.. J Dairy Sci 80: , Gilbert RO; et al. Theriogenology 33: , Hamilton SA; et al. Biology of Reproduction 53: , Hernandez J; et al. JAVMA 218: , Lucey S; et al. Vet Rec 118: , Lucy M. J Dairy Sci 84: , Melendez P. Thesis Master of Science. University of Florida ; 172 p, Nanda A; et al. Res Vet Sci 49:25-28, Noble KM; et al. J Repro Fert 120: , Nocek JE. J Dairy Sci 80: , Peter AT; et al. Theriogenology 33: , Rajala-Shultz PJ; YT Gröhn. Prev Vet Med 41: , Rajala-Shultz PJ; et al. J Dairy Sci 82: , Revah I; WR Butler. J Reprod Fert 106:39-47, Rowlands G; et al. Vet Rec 117: , Singh S; et al. Vet Rec 133: , Watson ED; CD Munro. British Veterinary Journal 140: , Whay HR; et al. Vet J 154: , Wohlt JE; et al. J Dairy Sci 77: ,

26 Table 1. Overall reproductive responses for lame and non-lame cows. a, b: statistical differences P 0.05 Response Lame cows Controls CRFS (%) 17.5 a 42.6 b PR (%) 85.0 a 92.6 b Ovarian Cysts (%) 25.0 a 11.1 b Days to First Service 98.8± ±5.5 Table 2. Summary of Logistic Regression Models Dependent variable Independent Varaibles OR 95% CI OR P-value CRFS Lameness: No Parity: Multiparous Calving season: no summer Milk yield: (< 11,000 kg/yr) Ovarian Lameness: yes Cysts Parity: Multiparous Calving season: no summer Milk yield: (< 11,000 kg/yr) Table 3. Cox proportional hazard model for overall pregnancy rate Variable Hazard Ratio 95% CL P-value Lameness: Yes Parity: Multiparous Milk yield: (< 11,000 kg/lactation) Calving Season: summer Survival curves for risk of non-pregnancy in lame and non-lame cows lame non-lame days in milk 342

27 AN EVALUATION OF LAMENESS IN A LARGE DAIRY HERD IN THE STATE OF SACHSEN-ANHALT, GERMANY L. Petrie 1, and J.G. Ferguson 2 WCVM, University of Saskatchewan, Saskatoon, Canada 1, Chirurgischen Tierklinik, Universität Leipzig, Leipzig, Germany 2 Introduction Lameness in dairy cows has an economic impact on the herd, but, additionally, it is also a welfare issue 1,4. The annual incidence varies greatly among farms, and several studies have yielded values of 25%-30%, but a detailed survey in the U.K. revealed a mean annual incidence of 55%. In the former East Germany, many dairies with more that 1000 milking cows were established. The importance of good foot care and the prevention of lameness in these herds was well recognized 6. The causes of lameness and distribution of lesions in these herds have also been recorded 2. Access to both the computer records and the raw data for 1999 for a large dairy herd milking approximately 1300 cows in the state of Sachsen-Anhalt, Germany, provided the opportunity for a retrospective study on the incidence and causes of lameness in a herd which had been established in Materials and Methods Through the generosity of the management, access was gained to both the lameness computer records and the raw data for the period from mid-march through mid-december 1999 for a large dairy herd in south-east Sachsen-Anhalt, Germany. The information, culled from both sources, was entered into a database. In 1999, the mean monthly number of cows in milk in the herd was 1300, comprising Schwarzbuntes Milch Rinde, Friesian, Holstein, and crosses of these breeds. The herd, which was fed a corn silage-based diet with an average annual milk yield in 1999 of 6800 kg, was permanently housed in a free-stall facility capable of holding more than 1700 cows. Within this free-stall building, cows were segregated into units of 100 free-stalls, housing 96 cows and consisting of 3 rows of freestalls of approximately 33 free-stalls in length with access to a full length feed bunk with feed delivered by an overhead conveyer belt. The free stalls measured 210 cm x 105 cm (internal width) and had a concrete base covered by a solid rubber mat; the rear step was 15.5 cm high. The flooring of the two alleys in each unit consisted of concrete slats 13 cm wide with a 3.5-cm gap. Lame cows were examined, diagnosed, and treated by a trained onfarm foot trimmer who also recorded the data for subsequent computer input; only the affected limb was identified. The data were examined and cases of lameness were determined from the records as previously defined 3. Results Incomplete data were available for March and December 1999 and these data were removed. The mean monthly number of cows in-milk for the 8 months April through November was 1335 ± 48.5 (SD). During that period, 745 individual cows were treated for lameness; 468, 189, 63, 23, 1, and 1 cows had 1, 2, 3, 4, 5, and 6 episodes of lameness respectively during the eight-month period. Each lame cow was examined and/or treated on an average of