**Risk (Predisposing) Factors for Non-Infectious Claw Disorders in Dairy Cows Under Varying Zero-Grazing Systems**

 J. Nguhiu-Mwangi, P.M.F. Mbithi, J.K. Wabacha and P.G Mbuthia *Department of Clinical Studies, Faculty of Veterinary Medicine, University of Nairobi,* 

*Kenya* 

#### **1. Introduction**

392 A Bird's-Eye View of Veterinary Medicine

Kruszewska, D. & Tylewska-Wierzbowska, S. (1993). *Coxiella burnetii* penetration into the

Kruszewska, D.; Lembowicz, K. & Tylewska-Wierzbanowska, S. (1996): Possible sexual

La Scola, B. & Raoult, D. (1996). Serological cross reactions between *Bartonella quintana*, *Bartonella henselae*, *and Coxiella burnetii*. *J Clin Microbiol,* 34, pp. 2270-2274 Lepe, J.A. & Guerro, F.J.; Del Castillo, E. (1999): The epidemiology of Q fever in the northern

Lutyński, R. (1956). First focus of Q fever on the territory of Poland. *Przegl Lek* 12, pp. 187-

Marmion, B. P.; Ormsebee R. A.; Kyrkou, M. & Wright, D.; Worswick, A.; Cameron, S.;

Moquin, R.R. & Moquin, M.E (2002). Weapons of mass destruction: biological. *Neurosurg* 

Muskens, J.; Engelen, E.; Maanen van, C.; Bartels, C. & Lam, T. J. G., M. (2011). Prevalence of

Musso, D.& Raoult. (1997). Serological cross-reactions between *Coxiella burnetii* and

Niemczuk, K. (2010) Q Fever - epidemiology, zoonotic aspects and administrative

Seshardi, R.; Paulsen, I.T.; Elisen, J.A.; Read, T.D.; Nelson, K.E.; Nelson, W.C.; Ward, N.L.;

Sidi-Boumedine, K.; Rousset, E.; Henning K.; Ziller, M.; Niemczuk, K.; Roest H.I.J. & Thiéry

Spicer A.J. (1998) Military significance of Q fever: a review. *J Roy Soc Med*, 71, pp. 762-765 Vodkin, M. H.; Williams, J. C. & Stephenson E. H. (1986). Genetic heterogeneity among

Webster, J. P.; Lloyd, G. & Macdonald D. W. (1995). Q fever (*Coxiella burnetii*) reservoir in

Willems, J. C.; Jäger C. & Baljer, G.: (1998). Physical and genetic map of the obligate intracellular bacterium *Coxiella burnetii. J Bacteriol*, 180, pp. 3816-3822

Tettelin, H.; Davidsen, T.M.; Beanan, M.J.; Deboy, R.Y.; Daugherty, S.C.; Brinkac, L.M.; Madupu, R.; Dodson, R.J.; Khouri, H.M.; Lee, K.H.; Carty, H.A.; Scanlan, D.; Heinzen, R.A.; Thompson, H.A.; Samuele, J.E.; Fraser, C.M. & Heidelberg, J.F. (2003). Complete genome sequence of the Q-fever pathogen *Coxiella burnetii*. *Proc* 

R. (2010). Development of harmonised schemes for the monitoring and reporting of Q fever in animals in the European Union. Scientific. Scientific report submitted to

wild brown rat (*Rattus norvegicus*) populations in the UK. *Parasitology*, 110, pp. 31-

Prusakowski, M. (2001). Bioterror. Jak się nie dać zabić. Tower Press, Gdańsk, pp. 66-68. Roest, I.J.H.; Ruuls, R.C.; Tilburg, J.J.H.C; Nabuurs-Franssen, M.H. & Klaassen C.H.W. at all.

Esterman, A.; Feery B.; Collins W. (1984). Vaccine prophylaxis of abattoir-

*Coxiella burnetii* infection in Dutch dairy herds on the testing bulk tank milk and

transmission on Q fever among human. *CID*, 22, pp. 1087-1088

area of Huelva, Spain. *Enferm Infecc Microbiol Clin*, 17, pp. 65-68

individual samples by PCR and ELISA. *Vet Rec*, 168, pp. 79

*Legionella micdadei*. *Clin Diagn Lab Immunol*, 4, pp. 208-212

EFSA, www.efsa.europa.eu/de/supporting/pub/48e.htm

isolates of *Coxiella burnetii. J Gen Microbiol,* 132, pp. 455

*Infect Immun*, 10, pp. 4188-4195

Little, T.W.A. (1999). Q fever. *Br Vet J*, 139, pp. 277-283

associated Q fever. *Lancett*, pp. 611-6161 Maurin, M. & Raoult, D. (1999). Q fever. *CMR*, pp. 518-553

proceedings. *PIWet-PIB*, Pulawy, pp. 1-35

*Focus*, 12, pp. 1232-1236

*Emerg Infect Dis*, 4, 668-675

*Natl Acad Sci USA*, pp. 5455-5460

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reproductive system of male mice, promoting sexual transmission of infection.

Lameness in cattle is one of the major causes of economic losses in dairy production systems (Hernandez et al., 2005; Kossaibati & Esslemont, 1997). These losses occur through various negative impact directly on cattle and indirectly on the dairy production system. These include reduced milk yield (Hernandez et al., 2005), discarding of milk due to withdrawal period of drugs used to treat some of the lameness conditions, cost of veterinary drugs and professional services in managing the conditions (Enting et al., 1997), lowered conception rate and increased calving interval (Melendez et al., 2003; Sogstad et al.,2006), reduced ovarian activity during early postpartum period (Garbarino et al., 2004), as well as premature culling and occasional mortalities (Enting et al., 1997). Lameness has also been identified as a major welfare determinant in cattle because of discomfort and pain that it causes (Offer et al., 2000).

Claw lesions account for between 60% and 90% of all lameness incidences in cattle in various countries of the world (Bergsten et al., 1994; Manske et al., 2002; Weaver, 2000). More than 60% of lameness in cattle is caused by lesions and disorders affecting the horn of the claw such as sole ulcers, heel erosion, sole bruising, white line separation and underrun (double) soles. All these claw disorders and lesions have a direct or indirect effect on the dermis (corium) of the claw and are associated with laminitis ( Belge & Bakir, 2005; Manske et al., 2002; Nocek, 1997). They are common in cattle raised under intense systems and feedlots (Smilie et al., 1991). Claw horn disorders in cattle are discernible at clinical level by lameness symptoms or at subclinical level by hoof trimming to reveal non-painful lesions within or under the horn (Clarkson et al., 1996; Nocek, 1997).

However, adoption of confined housing in dairy cattle husbandry as is the practice in smallholder dairy production systems particularly in developing countries has led to higher incidences of claw disorders. This is mainly due to cattle spending long hours standing on confined hard floors that exposes claws to higher pressures which predispose them to

Risk (Predisposing) Factors for Non-Infectious

**2.2 Zero-grazing unit and animal selection** 

rainfall season) respectively.

either odd or even serial numbers.

**2.3 Study design and data collection** 

Claw Disorders in Dairy Cows Under Varying Zero-Grazing Systems 395

distinct seasons, March to June (long rainfall season) and October to December (short

Evaluation of 32 smallholder zero-grazing dairy units purposively selected was done, in which cows were also examined for lameness and claw lesions. The zero-grazing units selected were those with 5-20 adult dairy cows. The farmers owning most of the zerograzing units were skeptical and hesitant to allow their dairy units evaluated or their cows examined. This was the reason for purposive selection of the zero-grazing units used in this study. The cows that were included in the study of claw lesions were those that had calved at least once with parities ranging between first and fourth. Those with 3rd and 4th parities were 60% and those with 1st and 2nd parities were 40% of the total population examined. All the selected cows whether lame or non-lame were examined. All the cows that had the study criteria were tagged with serial numbers 1, 2, 3, to n, where n was the serial number of the last cow being selected in the zero-grazing unit. To avoid biased numbering of the cows, assigning of serial numbers was randomly done by an independent worker employed in the zero-grazing unit. Then the author did the systematic selection of individual cows from the serialized groups by picking every second cow from the serial numbers. For example in the serial n1 to n10, if the first cow selected was n1, the next serially selected would be those with odd serial numbers (n1, n3, n5, n7, and n9). But if the first cow selected was n2, the next serially selected would be those with even serial numbers (n4, n6, n8 and n10). The serial numbers of the first cow selected was alternated between n1 and n2 from one zero-grazing unit to the next. Therefore, the cows selected in any zero-grazing unit were all those with

The data were collected in a cross-sectional study in which each smallholder zero-grazing dairy unit was visited only once. During the single visit, the zero-grazing unit was evaluated and data recorded on possible risk factors of claw conditions. The selected cows were also evaluated for claw lesions as well as animal-level risk factors of claw lameness conditions. Data on animal-level risk factors were collected by the author administering questionnaires to the farmers or to the persons employed to manage the zero-grazing units as respondents before examination of each cow. These data included breed of the cow, parity, milk yield per day and lactation stage. The questionnaires were structured with simple "Yes" or "No" and "I do not know" responses to minimize variations and information bias from the respondents. From the 32 smallholder zero-grazing units, 300 dairy cows were examined for claw lesions and animal-level risk factors. Out the 300 cows, Friesians were 76% (228), Ayrshires 20% (60) and the remaining 4% (12) were a mixture of Guernsey and Jersey. Data from unit-level risk factors were collected during visitation to each of the 32 smallholder zero-grazing units. Some of the data (housing and stall design, number of cubicles, type of cubicle bedding, type of floor, presence or absence of a curb (kerb) at the rear end of the cubicles, lunging space, bob zone, presence or absence of neckbar over the feeding bunk/trough and adequacy of feeding space) were collected through observational (qualitative) method. Other data such as curb height and height of neck-bar from the top surface of feeding trough were collected through actual measurements, while

circumscribed excessive local loading, thus stimulating more horn production and enlarging of the claws. A positive correlation exists between the time cows spend on hard floors and development of claw horn lesions. This confinement further adversely affects behavior and welfare of cattle (Bergsten, 1994: Somers et al., 2003; van der Tol et al., 2003). These practices synergistically with high levels of concentrate diets exacerbate the occurrence of claw-horn disorders (Cook et al., 2004; Donovan et al., 2004; Nocek, 1997; Somers et al., 2005; Vermunt, 2004). Feeding cattle with diets that lead to low-grade prolonged lowering of rumen pH could result in an up-surge of lameness due to increased incidences of laminitis. Excessive feeding of rapidly fermented carbohydrates and finely chopped fodder silage enhance development of laminitis due to their tendency of initiating subacute ruminal acidosis (SARA), which is also aggravated by a fall in the ratio of concentrate to forage (C:F) (Vermunnt, 2004). However, supplementing cattle with minerals and vitamins tends to improve claw health and reduce likelihood of developing laminitis and sole lesions (Bergsten et al., 2003; Tomlinson et al., 2004). Previous publications based on retrospective data show that improvement of cattle housing in the zero-grazing units from earthen slurryladen floors to concrete floors, has led to a shifting from high prevalence of infective claw lesions and low prevalence of non-infectious laminitis related disorders to high prevalence of laminitis related disorders and low prevalence of infective claw lesions (Gitau, 1994; Mbithi et al., 1991; Nguhiu-Mwangi et al., 2009).

In developing Kenya where this research on association between non-infective claw disorders and risk factors was carried out, increased human population has led to inevitable reduction in per capita land-holdings. This has invariably led to diminished grazing land and subsequently triggering an increase in smallholder zero-grazing dairy production units particularly for the low income households (Mutugi, 2004). Rearing of dairy cows in smallholder zero-grazing units in developing countries is inevitable since they are part of the livelihood of the high population of low class smallholder farmers. For example in Kenya, smallholder units contribute 80% of the national commercial dairy herd (Wanyoike & Wahome, 2004). These smallholder dairy production units in Kenya have varied designs and management practices. They are so varied unit to unit and sometimes within individual units that they can be further classified as subunits. They completely lack standardization of housing designs, nutritional regimen and management protocols (Nguhiu-Mwangi, et al., 2008). Prevalence of claw disorders in dairy cows raised under smallholder zero-grazing systems in Kenya and possible risk factors leading to development of these claw disorders has not been documented previously. Therefore, the study was carried out in Kenya to verify the types of claw disorders in dairy cows that are raised in the smallholder subunits under varied zero-grazing systems and to find out through statistical analysis whether there is any association between these subunit-level factors, animal-level factors and the claw disorders.
