Locomotion Scores And Their Associated Factors In Dairy Cows Within The Smallholder Zero-grazing Units In Kikuyu District, Kiambu County, Kenya
The designs and management practices in the smallholder zero-grazing dairy units in Kenya vary greatly between and within the dairy units. These variations serve as part of the risk factors for occurrence of claw disorders in the zero-grazed dairy cows. Early diagnosis of claw disorders is paramount for providing prompt corrective measures before irreversible claw damage occurs. Locomotion scoring systems have been employed as reliable method of making early diagnosis of cattle lameness. However, locomotion scores have not been evaluated in dairy cows reared under such varied smallholder zero-grazing factors. With this background, a study was designed for smallholder zero-grazing dairy units in Kikuyu district, Kiambu county, Kenya, to achieve the following objectives: 1. to evaluate farmers’ knowledge, perspective and practice of claw trimming and how these are associated with locomotion scores of dairy cows, 2. to determine the dimensions, conformation and disorders of claws and how these are associated with locomotion scores of dairy cows, 3. to determine floor characteristics and slurry management in the smallholder zero-grazing units and how these factors influence locomotion scores of dairy cows. It was a cross-sectional study carried out in 100 purposively selected smallholder zero-grazing dairy units from which 161 dairy cows were selected and each examined. Each cow was evaluated and examined once for locomotion scores and claw disorders respectively, during the visits. The 5-score scale locomotion scoring system was used, which is based on back posture and limb placement was employed. Some of the data collected through visual observation and physical examination. They included: measurements of claw dimensions such as claw angle, toe length, heel height, claw height, claw diagonal, claw width and sole length. Presence or absence of claw disorders as well as floor characteristics were likewise evaluated by visual observation. xvi Other data were collected using structured questionnaire and these included lactation stage, parity, slurry removal, farmer awareness and perspective on claw trimming as well as whether or not claw trimming is done. Locomotion scores were determined by walking the cows within the unit and making observations. All data were recorded in data collection sheets. Data analysis included descriptive statistics and simple associations between variables and outcome using chi-square and simple one-way analysis of variance at p< 0.05 significance level. The results indicated 94% of the farmers were aware of claw trimming, but cows were trimmed in only 43% of the units. The average locomotion score was 1.3 among the 161 zero-grazed dairy cows examined, which means they had either normal gait or mild lameness. Locomotion score was strongly associated with toe length [(F (2, 158) =11.77, p < 0.0001)] and the claw angle [(F (2, 158) =5.41, p = 0.0054)]. The claw disorders that had strong association with locomotion scores included corkscrew claws (O.R.=1.3, χ² = 35.43, p < 0.0001), underrun (double) soles (O.R.=1.1, χ² = 33.67, p < 0.0001), White line separation (O.R.=1.1, χ² = 24.23, p < 0.0001), overgrown claws (O.R.=1.1, χ² = 10.90, p = 0.0043), traumatic pododermititis (O.R.=1.7, χ² = 9.3758, p = 0.0092) and horizontal hoof wall cracks (O.R.=1.2, χ² = 9.29, p = 0.0096). The claw lesion weakly associated with locomotion scores was sole ulcer (O.R.=1.1, χ² = 5.9931, p = 0.0490). The animal-level factors that had significant association with locomotion scores were breed of the cow (O.R.=1.2, χ² = 18.55, p = 0.0026), parity (O.R.=1.2, χ² = 14.20, p = 0.0060) and lactation stage (O.R.=1.1, χ² = 10.84, p = 0.0367). Type of floor was found to significantly (O.R.=1.5, χ² = 40.47, p = 0.0016) influence locomotion score, with higher locomotion score recorded in cows on extremely smooth concrete floors. Frequency of claw trimming was the only factor on claw trimming practice that was associated (O.R. = 1.30, χ² = 30.21, p = 0.0112) with xvii locomotion scores. By using locomotion scores the study concludes that dairy cows in the smallholder zero-grazing units are either not lame or mildly lame. However, observationally the claw disorders and lesions looked more severe than the corresponding locomotion scores. This leads to further conclusion that, observational locomotion scoring system may not be highly sensitive under the designs and floor types found in these smallholder zero-grazing dairy units. Further research on evaluation of sensitivity and validity of using locomotion-scoring systems for diagnosis of lameness under the varied smallholder zero-grazing dairy units in Kenya needs to be carried out. In addition, training of farmers on proper management of factors that predispose zero-grazed dairy cows to lameness is pertinent.