Medycyna Wet. 2010, 66 (12) 818
Artyku³ przegl¹dowy Review
Lameness in dairy cows is a clinical sign with a multifactorial etiology and it has been classified as one of the three most common health problems, after infertility and mastitis, which present an increased risk of culling in dairy cows (8). According to Rajala--Schultz and Gröhn (24), mastitis, teat injuries and lameness are the diseases that have the greatest im-pact on culling, increasing the risk of culling throughout the lactation. Many studies indicate a considerable disparity in lameness incidence in dairy herds, ranging between 2.1 and 50% (3, 7, 8, 12-14, 30). Probably these results were associated with the difficulty of de-fining clinical lameness (CL) even among specialists, as well as the varying skills of the personnel responsible for identifying lame cows (3, 5). Currently, cows are locomotion scored (LOCO) according to a key using a 5-point scale suggested by Sprecher et al. (28). CL was defined by these authors as a ³ 3 lameness score.
Incidence and prevalence of lameness and their
relationship to milk yield in high-yielding cows
JAN OLECHNOWICZ, JÊDRZEJ M. JAKOWSKI
Department of Veterinary, Faculty of Animal Breeding and Biology, Poznañ University of Life Sciences, Wojska Polskiego 52, 60-625 Poznañ, Poland
One of the difficulties in estimating economic losses due to clinical lameness in dairy cows has been to obtain accurate data on the effect of lameness on milk production (30), as the results of many studies in this respect are inconsistent. Results of a majority of studies indicated a decreased milk production by lame cows (1, 8, 11-13, 17, 25, 26, 30), while others showed no such effect (6, 21). The aim of this paper was to present on the basis of results of conducted research the associations of clinical lameness in cows with their milk yield.
Incidence and prevalence of lameness in herds of dairy cows
The incidence rate of lameness was defined as the number of new cases during a stated period of time relative to the mean population over the period and could then be calculated (5). The mean rate incidence
Olechnowicz J., Jakowski J. M.
Incidence and prevalence of lameness and their relationship to milk yield in high-yielding cows
Summary
The aim of this study was to present, on the basis of results of the conducted research, associations of clinical lameness with milk yield in cows. Lameness in dairy cows is an important disease with a multifactorial etiology and represents one of the three most common health problems, after infertility and mastits. Currently it is the reason for an increasing risk of culling in dairy cows, especially in high yielding herds. The incidence of lameness was from 2.1% to 50% per 100 cows. Some studies indicated that the incidence of lameness increases with lactation rank, while others do not state a significant effect of parity on lameness incidence. The prevalence of lameness ranged from 5% to 24.6%. The main factors influencing the prevalence of lameness in dairy cows include calendar season of the year, comfort of stalls, hoof trimming frequency and the presence of concrete floors. The main causes of diagnosed lameness include sole ulcers (SU), white line diseases (WLD), interdigital necrobacillosis (IN) and digital dermatitis (DD). Results reported in literature indicate consider-able differences in the incidence of clinical lameness (CL) in dairy cows, from 2.1 to 50%. This is associated with difficulties in its definition and identification in cows. Many authors reported that CL is associated with decreased milk production by lame cows, especially in the initial period of lactation. Some data indicate a reduced milk yield through lactation in clinically lame high-yielding cows, amounting to 574 for SU and 369 kg for WLD. Cows culled due to foot disorders had daily milk, fat and protein yields significantly lower by 11.3, 14.1, and 16.4%, respectively. Other authors found no association between lameness and milk yield, while some are of the opinion that this relationship occurs only during mid- and late lactation. Several authors reported that the effect of claw and limb disorders on milk yield is not direct, since many factors influence milk production, e.g. feeding routine and nutrition. The use of different statistical analyses in the elaboration of data may lead to different results.
Medycyna Wet. 2010, 66 (12) 819
of lameness was 54.6 new cases per 100 cows within the range from 10.7 to 170.1. Hernandez et al. (13) reported that in their study among 531 cows one hundred sixty-seven (31%) animals were affected with lameness. In another study clinical lameness occurred in 22% cows kept on concrete-slatted flooring and in 26% kept on rubber-matted slatted flooring (18). A low 35% (636 cows out of 1824 cows) were lame with at least one lesion and approximately 25% cows had at least one repeat of the same lesion in the lacta-tion (1). Similarly, the total incidence of lameness was 23.3% (a total of 3,623 cows at 846 lame cows) in a study by Bicalho et al. (4). According to those authors, the incidence of lameness by parity was 10.3% for parity 1, 24.5% for parity 2 and 34.0% for parity ³ 3. The lowest incidence of lameness per herd (9.02%) was given in another study (17). The effect of parity (1, 2, 3) on lameness incidence according to those authors was not significant.
The prevalence of lameness was measured by regular visits to herds, during which locomotion was scored on a 1 to 5 point scale and after each visit the preva-lence of lameness was calculated as the proportion of cows with scores of 3 or more. The mean prevalence of lameness for the 37 farms was calculated in 20.6 per cent with a range from 2.0 to 53.9 per cent. The mean prevalence of lameness during summer and winter was 18.6 and 25%, respectively (5). Prevalence of clinical lameness was analyzed also by Espejo et al. (10) and Espejo and Endres (9) in 53 high-producing groups of Holstein cows. According to those authors, the prevalence of lameness averaged 24.6% within a range from 3.3 to 57.3%. Under commercial condi-tions many factors were associated with the prevalence of lameness, e.g. the time that cows spend away from their pen during milking, comfort of stalls, hoof trim-ming frequency, and the presence of concrete floors. The prevalence of lameness was higher in spring as compared to autumn and when the herd was open versus closed (27). Cows which are kept on the pasture for longer periods during summer also had a lower prevalence of lameness. This study also showed that cows housed in cubicles were more likely to be lame as compared to those kept on straw. Higher yielding cows were also more likely to be lame and those youn-ger at first calving had a higher lameness prevalence. A low prevalence of lameness in Swedish dairy cows (5%) was described by Manske et al. (20).
The diagnoses of clinical lameness
In dairy herds over 70% of cows became lame at least once. Clinical lameness was caused mainly by sole ulcers (SU), white line diseases (WLD), inter-digital necrobacillosis (INB) and inter-digital dermatitis (DD) (12, 18). The incidences of these disorders were 9 to 11 cases/100 cows per year. Many authors reported that SU was the most common lesion causing clinical lameness in dairy cows (3, 5, 18-20), but others
indi-cated an unusually high incidence of DD (30). Accor-ding to Hernandez et al. (13), most lame cows had claw lesions (60%), followed by papillomatous digital dermatitis (PDD) (31%) or interdigital phlegmon (IP) (9%). Out of 1824 cows from 30 farms there were 230 cows diagnosed with SU (84% lateral and 16% medial), 169 cases of WLD (93% lateral and 7% medial), 137 of DD and 238 other lesions (1). The presence of SU and DD was associated with an incre-ased locomotion score (29). Those authors suggested that the presence of other lesions was not associated with an increased locomotion score. Cows housed throughout the year and fed a high-concentrate diet are more prone to locomotive problems than cows managed in a more extensive system (23). The analysis within this study showed a significant relationship between a decreased body weight at lactations in 2 out of 5 of cows and increased locomotive problems. In tie stall herds SU was most commonly diagnosed in the spring (50% of diagnoses fell between 90 and 228 days), but the distribution of this disorder per year did not provide clear evidence (19). Similarly, in loose housed herds SU was most commonly diagnosed in the spring (50% of diagnoses fell between 81 and 207 days). In such herds parity and breed had a significant effect on the lactational risk of SU. The number of times a cow was hoof-trimmed had a significant effect on the risk of diagnosis of SU.
Lame cows by month and number of lactation In high-yielding cows the incidence of the first epi-sode of lameness peaked 3 months after calving (12). Lameness appeared in cows in the early lactation and was more likely to occur in older cows (30). A Dutch study also reported a higher incidence of lameness in the early lactation (3). Hernandez et al. (14) reported that a large number of new cases of cows classified as lame during the first 15 weeks after parturition were in the first week of postpartum. The significant effect of lactation weeks on lameness incidence was found by Kocak and Ekiz (17), which stated that most of the lameness events were in the first four weeks and secondly in the period of 5-8 weeks, in both periods there were 54.65% of lameness events. In contrast, no associations were found between the month of lactation and the prevalence of lameness in the first 10 months of lactation (10). Similarly, no associations were found between lameness and days in milking (DIM) of cows in a study of 20 dairy herds (31). In another study it was found that the greatest incidence of lameness in cows occurred between 4 and 8 months in milk (2). The lowest prevalence of lameness was observed in first lactation cows and the prevalence increased with lactation number (10, 27). The greatest prevalence of lameness was observed in the group of cows with 6 or more lactations, in which approxima-tely every second cow was clinically lame. Similarly, lameness was significantly more common in older
Medycyna Wet. 2010, 66 (12) 820
cows (30). Prevalence of lameness was also higher in spring as compared to autumn and when the herd was open versus closed (27).
The effect of lameness on milk production in high-yielding cows
The relationship between hoof health and milk pro-duction is complex. Clinical lameness reduces milk yield for a certain time period around disease occur-rence (7, 8, 12, 17, 25, 30). However, despite this fact hoof diseases are usually observed with high level milk production in the same time or preceding lactation (3, 11, 23, 26). Lame cows when compared with non-lame (control) cows had similar milk production before the diagnosis of lameness in the same herd (two dairy herds), lactation and stage of lactation (30). After the diagnosis of lameness in the first herd, milk produc-tion of lame cows was lower on average by 1.5 kg/d ³ 2 weeks after lameness than milk production of control cows. In the second herd, milk production of lame cows was lower by 0.8 kg/d in the first and se-cond weeks after lameness and by 0.5 kg/d ³ 3 weeks after diagnosis. The decrease in milk production was larger for cows in the second lactation and following lactations than for those in their first lactation. In the first herd foot rot and food warts were associated with a smaller reduction of production than that for sole ulcers (SU), but in the second herd cows with foot abscesses and foot rot showed a trend towards a larger decrease in milk production.
Clinically lame cows showed losses in milk produc-tion over 4 months before the diagnosis of lameness, and over 5 months after the diagnosis of lameness (12). Larger decreases in milk production were recorded after the diagnosis of lameness and the mean estimated reduction in milk production in cows lame in the fifth month of lactation amounted to 357 kg of milk in the 305-d lactation. DD was associated with a 10% decre-ase of milk yield, but these losses were not significant (13). Milk and milk protein yield decreased linearly as the locomotion score increased (16). Increased loco-motion score was associated with increases in the per-centage of cows lying down. In a study by Hernandez et al. (14) cows were examined for lameness during the first 100 days after parturition and scored weekly according to a 6-point locomotion scoring system (from 0 to 5 points). Cows were classified to 1 out of 3 cate-gories of lameness: non-lame, moderately lame and lame. Milk yield in lame cows (346 days of lactation, 11 545 kg) was significantly lower than milk yield in moderately lame cows (347 days of lactation, 12 071 kg), but it was not significantly different from that in non-lame cows (336 days of lactation, 11,865 kg). These results indicate that early detection of lameness is important for milk production throughout lactation. Milk production of cows with scores of 4 was asso-ciated with losses of 0.78 kg in daily milk yield com-pared with cows with a score of 1 (23). Similarly,
daily production in cows which scored 5 points was a reduction in milk yield by 5.5 kg.
High-yielding cows were more likely to be lame and produced more milk by lactation (1.12 kg/d) than cows that were never lame, i.e. a mean of 342 kg of milk over 305 DIM (days in milking) (12). Espejo and Endres (9) reported that high-yielding cows had higher milk production (37.6 kg/d), a lower average DIM (167.9) and a higher lactation number (2.64) when compared with cows from both other herds, which produced milk at 32.9 kg/d, with an average DIM of 207.7 and lactation number of 2.23. Some of these traits could be associated with a higher preva-lence of clinical lameness. Results presented in a study by Hultgren et al. (15) showed that SU in cows is associated with a reduced reproductive performance and a high milk production in the same lactation. Dif-ferent results for high-yielding cows were presented by Amory et al. (1). According to those authors such cows were also more likely to become clinically lame with SU or WLD than unaffected cows. These claw diseases were significantly associated with milk loses. When these diseases were diagnosed in the 5th month
of lactation, then the mean decreased yield per lacta-tion amounted to 574 kg and 369 kg, respectively. Digital dermatitis (DD) or the presence of other foot lesions were not associated with reduced milk pro-duction. Lameness was associated with milk losses during the disease period and 1 week after diagnosis, but it did not influence milk yield in the 305-d lacta-tion (17). Cows with a high LOCO score approached feed troughs at similar times as non-lame cows (2). The number of visits to the automatic milking system (AMS) decreased with an increasing LOCO score. In consequence, lame cows produced less milk when compared with non-lame cows.
Cows with a digital disease which were not culled for that reason had a similar daily milk production (24.4 kg), fat production (1.00 kg) and protein production (0.79 kg) as other cows: 25.6 kg, 1.01 kg and 0.77 kg, respectively, and these differences were not significant (8). According to those authors, cows that were culled for that reason had milk, fat and protein productions significantly lower by 11.3, 14.1 and 16.4%, respecti-vely.
Other diseases also influenced a decreased milk production of dairy cows. For example, a significant association was found between milk yield in the 305-d current lactation and the following risk factors: ova-rian cysts, claw diseases, milk fever, and between the lactation number and current lactational incidence risks of retained placenta, mastitis, claw diseases, milk fever, and ketosis (11). Milk fever results in losses in milk yield of cows in the period of 4 to 6 weeks after calving, from 1.1 to 2.9 kg/d, respectively (25). Lame-ness in cows also had a negative effect on their milk yield, in this respect cows in parity 1 were affected most. The synergistic effect of the three common
con-Medycyna Wet. 2010, 66 (12) 821
ditions for cows, i.e. high somatic cell counts in milk (SCC), low body condition (BCS) and lameness, needs to be further investigated (22). These conditions in-fluence the level of milk production, reproduction and culling rate of cows.
The results obtained by the authors of this study (results so far unpublished) showed that for Polish Holstein cows, which were clinically lame for a month and which were clinically lame for more than a month (maximum per 2 months) the total mean estimated reduction in milk yield per 120-d lactation was appro-ximately 308 and 283 kg, respectively, as compared with cows that were never lame in early lactation.
Recapitulation
According to data given in literature the incidence of lameness was from 2.1% to 50% per 100 cows. Some studies indicated that the incidence of lameness increased together with lactation rank; however, others did not state a significant effect of parity on lameness incidence. The prevalence of lameness ranged from 5% to 24.6%. Higher yielding cows were more likely to be lame. The prevalence of lameness depends on many factors such as calendar season, comfort of stalls, hoof trimming frequency and the presence of concrete floors. Herds of cows with an earlier age at first calving had higher lameness prevalence. Many authors reported that a higher incidence of lameness is found in early lactation and increases with lactation number. Data reported in literature indicate a considerable difference in the incidence of clinical lameness (CL) in dairy cows, as well as a difficulty in the definition of CL and different skills of personnel responsible for identifying lame cows. Probably this results in the difficulties in estimating the effect of CL on milk production in dairy cows. Further investigations need to take into consideration the synergistic effect of three common conditions for cows: somatic cell counts in milk, body condition and CL.
References
1.Amory J. R., Barker Z. E., Wright J. L., Mason S. A., Blowey R. W., Green L. E.: Associations between sole ulcer, white line disease and digital dermatitis and the milk yield of 1824 dairy cows on 30 dairy cow farms in England and Wales from February 2003 - November 2004. Prev. Vet. Med. 2008, 83, 381-391.
2.Bach A., Dinarés M., DEvant M., Carré X.: Associations between lameness and production, feeding and milking attendance of Holstein cows milked with an automatic milking system. J. Dairy Res. 2007, 74, 40-46. 3.Barkema H. W., Westrik J. D., van Keulen K. A. S., Schukken Y. H., Brand A.:
The effects of lameness on reproductive performance, milk production and culling in Dutch dairy farms. Prev. Vet. Med. 1994, 20, 249-259.
4.Bicalho R. C., Warnick L. D., Guard C. L.: Strategies to analyze milk losses caused by diseases with potential incidence throughout the lactation: a lame-ness example. J. Dairy Sci. 2008, 91, 2653-2661.
5.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. 1996, 138, 563-567.
6.Cobo-Abreu R., Martin S. W., Willoughby R. A., Stone J. B.: The association between disease, production and culling in a University dairy herd. Can. Vet. J. 1979, 20, 191-195.
7.Coulon J. B., Lescourret F., Fonty A.: Effect of foot lesions on milk produc-tion by dairy cows. J. Dairy Sci. 1996, 79, 44-49.
8.Enting H., Kooij D., Dijkhuizen A. A., Huirne R. B. M., Noordhuizen--Stassen E. N.: Economic losses due to clinical lameness in dairy cattle. Livest. Prod. Sci. 1997, 49, 259-267.
9.Espejo L. A., Endres M. I.: Herd-level risk factors for lameness in high producing Holstein cows housed in freestall barns. J. Dairy Sci. 2007, 90, 306-314.
10.Espejo L. A., Endres M. I., Salfer J. A.: Prevalence of lameness in high--producing Holstein cows housed in freestall barns in Minnesota. J. Dairy Sci. 2006, 89, 3052-3058.
11.Fleischer P., Metzner M., Beyerbach M., Hoedemaker M., Klee W.: The rela-tionship between milk yield and the incidence of some diseases in dairy cows. J. Dairy Sci. 2001, 84, 2025-2035.
12.Green L. E., Hedges V. J., Schukken Y. H.: The impact of clinical lameness on the milk yield of dairy cows. J. Dairy Sci. 2002, 85, 2250-2256. 13.Hernandez J., Shearer J. K., Webb D. W.: Effect of lameness on milk yield
in dairy cows. J. Am. Vet. Med. Assoc. 2002, 220, 640-644.
14.Hernandez J. A., Garbarino E. J., Shearer J. K., Risco C. A., Thatcher W. W.: Comparison of milk yield in dairy cows with different degrees of lameness. J. Am. Vet. Med. Assoc. 2005, 227, 1292-1296.
15.Hultgren J., Manske T., Bergsten Ch.: Associations of sole ulcer at claw trim-ming with reproductive performance, udder health, milk yield, and culling in Swedish dairy cattle. Prev. Vet. Med. 2004, 62, 233-251.
16.Juarez S. T., Robinson P. H., DePeters E. J., Price E. O.: Impact of lameness on behavior and productivity of lactating Holstein cows. App. Anim. Behav. Sci. 2003, 83, 1-14.
17.Kocak O., Ekiz B.: The effect of lameness on milk yield in dairy cows. Acta Vet. Brno 2006, 75, 79-84.
18.Kremer P. V., Nueske S., Scholz A. M., Foerster M.: Comparison of claw health and milk yield in dairy cows on elastic or concrete flooring. J. Dairy Sci. 2007, 90, 4603-4611.
19.Kujala M., Dohoo I. R., Laakso M., Schnier Ch., Soveri T.: Sole ulcers in Finnish dairy cattle. Prev. Vet. Med. 2009, 89, 227-236.
20.Manske T., Hultgren J., Bergsten Ch.: Prevalence and interrelationships of hoof lesion and lameness in Swedish dairy cows. Prev. Vet. Med. 2002, 54, 247-263.
21.Martin S. W., Aziz S. A., Sandals W. C. D., Curtis R. A.: The association between clinical disease, production and culling of Holstein-Friesian cows. Can. J. Anim. Sci. 1982, 62, 633-640.
22.Morris M. J., Walker S. L., Jones D. N., Routly J. E., Smith R. F., Dobson H.: Influence of somatic cell count, body condition and lameness on follicular growth and ovulation in dairy cows. Theriogenology 2009, 71, 801-806. 23.Onyiro O. M., Offer J., Brotherstone S.: Risk factors and milk yield losses
associated with lameness in Holstein-Friesian dairy cattle. Animal 2008, 2:8, 1230-1237.
24.Rajala-Schultz P. J., Gröhn Y. T.: Culling of dairy cows. Part III. Effects of diseases, pregnancy status and milk yield on culling in Finnish Ayrshire cows. Prev. Vet. Med. 1999, 41, 295-309.
25.Rajala-Schultz P. J., Gröhn Y. T., McCulloch C. E.: Effect of milk fever, ketosis, and lameness on milk yield in dairy cows. J. Dairy Sci. 1999, 82, 288-294.
26.Rowlands G. J., Lucey S.: Changes in milk yield in dairy cows associated with metabolic and reproductive disease and lameness. Prev. Vet. Med. 1986, 4, 205-221.
27.Rutherford K. M. D., Langford F. M., Jack M. C., Sherewood L., Lawrence A. B., Haskell M. J.: Lameness prevalence and risk factors in organic and non-organic dairy herds in the United Kingdom. Vet. J. 2009, 180, 95-105. 28.Sprecher D. J., Hostetler D. E., Kaneene J. B.: A lameness scoring system
that uses posture and gait to predict dairy cattle reproductive performance. Theriogenology 1997, 47, 1179-1187.
29.Tadich N., Flor E., Green L.: Associations between hoof lesions and locomo-tion score in 1098 unsound dairy cows. Vet. J. 2010, 184, 60-65.
30.Warnick L. D., Janssen D., Guard C. L., Gröhn Y. T.: The effect of lameness on milk production in dairy cows. J. Dairy Sci. 2001, 84, 1988-1997. 31.Warnick L. D., Pelzer K. D., Meadows A. W., diLorenzo K. A., Whittier W. D.:
The relationship of clinical lameness with days in milk, lactation number, and milk production in a sample of Virginia dairy herds. J. Dairy Sci. 1995, 78 (suppl. 1), 169.
Authors address: Dr hab. Jan Olechnowicz, Osiedle Wichrowe Wzgórze 13/93, 61-675 Poznañ
