**3.2 The study design**

This was a prospective abattoir study in which claws were collected from slaughtered dairy cows. Claws from an abattoir and a slaughter slab were subject to the number of dairy cows slaughtered per given time.

### **3.3 The sample size and sample selection**

The two places selected from which dairy cow claws were collected included Kiserian abattoir and wangige slaughter slab. They were purposively selected based on the findings of an earlier pilot survey indicating that culled dairy cows were regularly slaughtered in these two places. Slaughter of dairy cows is not commonly done, hence the difficulties in getting their claws. The dairy cows send to slaughter were

**41**

*Macroscopic, Radiographic and Histopathologic Changes of Claws with Laminitis…*

which the claws were collected had been kept under zero-grazing system.

culled as a result of reasons related with poor production, poor reproductive performance, non-treatable problems and old age. The combined number of dairy cow feet collected from both slaughter places was 159, which made a total of 318 claws. A total of 96 feet were from Wangige slaughter slab, which had more dairy cows slaughtered and 63 were from Kiserian abattoir. Among the 159 feet, 109 were from the hind limbs and 50 from the forelimbs. More hind limb claws were collected based on the literature knowledge that they suffer more problems than forelimb claws. Since only a small number of dairy cows are slaughtered, it necessitated collection of the available claws without any random selection. History indicated that all the cows from

Each of claws collected from the abattoir and the slaughter slab was thoroughly washed. Observation of gross appearing lesions was done. Each lesion/abnormality was recorded in data collection sheets. Each claw was radiographed in dorso-palmar or dorso-plantar views. The radiographs were viewed and examined thoroughly. All radiographic changes seen were recorded. Owing to the time lapse between slaughter and examination, the claws were partially desiccated by loss of their water content, making trimming difficult. Therefore, after radiography, the area covered by the horn capsule was dipped in water for 2–3 h to make them softer for facilitation of trimming. Trimming was done by removing 2–3 mm of the horn of the sole, while observation of any lesion on the sole was made. All lesions were recorded. About 10 claws with subclinical laminitis and another 10 claws with chronic laminitis were purposively selected. Sagittal sections of all these 20 selected claws were done starting from the fetlock joint level through proximal, middle and distal phalanges. All gross lesions observed in the exposed corium and the phalanges after

The horn of the sole was removed from each claw using a knife to expose the corium of the sole fully. Sections of about 5 mm thickness of the corium specimens were harvested in transverse and longitudinal planes from each of the claw samples. The corium specimens were further sectioned into 1–2 millimetre pieces, which were dehydrated using ascending concentrations of absolute isopropyl alcohol, that started from 80 to 100%. Clearing of the tissues was done in xylene, then embedded in paraffin wax, blocked on wooden chunks, followed by fixing on the microtome. The tissues that were in paraffin wax blocks were cut into 5 μm thick pieces. From each block, four pieces of 5 μm thick tissues were made. This was followed by dewaxing the tissue sections in xylene and hydrated using graded alcohol whose concentration was from 100 to 50%. It was cleared in xylene, alcohol and washed in water. The tissues were stained with haematoxylin and eosin (H&E). Following dehydration, they were mounted on microscope slides and cover slips with Destrene 80, dibutyl phthalate and Xylene (DPX) mountant according to Ref. [25]. The slides were examined under light microscope using ×10, ×40 and ×100 objective lenses. The results were recorded and photomicrographs taken as necessary. The control in this study was done by comparing the findings in the normal claws with those that had lesions or were abnormal. The corium samples from claws that did not show signs of subclinical or chronic laminitis were processed using similar procedure as

Claw lesions were given numerical codes for ease of entry into the computer. The prevalence of claw lesions was computed using Microsoft Office Excel data

*DOI: http://dx.doi.org/10.5772/intechopen.81255*

**3.4 Examination of the claws for data collection**

sagittal section were recorded.

the test specimens and used as controls.

**3.5 Data management and analysis**

*Macroscopic, Radiographic and Histopathologic Changes of Claws with Laminitis… DOI: http://dx.doi.org/10.5772/intechopen.81255*

culled as a result of reasons related with poor production, poor reproductive performance, non-treatable problems and old age. The combined number of dairy cow feet collected from both slaughter places was 159, which made a total of 318 claws. A total of 96 feet were from Wangige slaughter slab, which had more dairy cows slaughtered and 63 were from Kiserian abattoir. Among the 159 feet, 109 were from the hind limbs and 50 from the forelimbs. More hind limb claws were collected based on the literature knowledge that they suffer more problems than forelimb claws. Since only a small number of dairy cows are slaughtered, it necessitated collection of the available claws without any random selection. History indicated that all the cows from which the claws were collected had been kept under zero-grazing system.

#### **3.4 Examination of the claws for data collection**

*Veterinary Anatomy and Physiology*

internally.

**3. Materials and methods**

its peri-urban region have an area of 696 km2

in Wangige area of Kiambu County, Kenya.

number of dairy cows slaughtered per given time.

**3.3 The sample size and sample selection**

**3.1 The study area**

**3.2 The study design**

the claws, while soft yielding floors lead to significant distribution of weight to the sole. The overall effect of the weight force against the mechanical pressure from the floor depends on the architectural arrangement of the claw wall determined by the interrelationship arrangement of tubular, intertubular and laminar horn cells. The numerical density of the horn tubules determines the differences in the stiffness and elasticity of the various parts of the claw horn capsule. The degree of the effect of the mechanical forces from the animal weight and floor pressure is associated with the degree of horn capsule elasticity and stiffness [22]. The longer the dairy cow stands on hard unyielding floor such as concrete, the more the likelihood of developing claw lesions [23]. Besides the pressure transmitted to the inside of the claws from the hard floors, the floor abrasiveness has a significant contribution to the occurrence of claw lesions, mainly due to excessive wearing of the claw-horn [24]. The claws are particularly prone to this abrasiveness of the floor when the horn produced is weak following bouts of laminitis [8]. Conversely, the claw-horn does not wear off when the cow lives and walks on soft yielding floors such as earthen floors or straw yards. This leads to inevitable overgrowth of the claws with subsequent overloading of the region towards the heel bulb, which is soft, hence the ease of transmission of pressure to the inner claw tissues, thus damaging them. The result of this is the production of poor quality horn [23]. All these factors have an overall effect of causing changes in the claw shape as well as structural changes

The study was carried out in the peri-urban areas of Nairobi City in the Republic of Kenya. The area was chose owing to its high number of smallholder zero-grazing dairy units. The high number of smallholder zero-grazing dairy units is instigated by the availability of market to which farmers sell milk and the value-added dairy products. The market is from the high number of city dwellers and workers. Nairobi and

This was a prospective abattoir study in which claws were collected from slaughtered dairy cows. Claws from an abattoir and a slaughter slab were subject to the

The two places selected from which dairy cow claws were collected included Kiserian abattoir and wangige slaughter slab. They were purposively selected based on the findings of an earlier pilot survey indicating that culled dairy cows were regularly slaughtered in these two places. Slaughter of dairy cows is not commonly done, hence the difficulties in getting their claws. The dairy cows send to slaughter were

It is located between latitude 01° 18′S and longitude 36° 45′E with an altitude of 1798 m above sea level. The estimated annual rainfall is maximum of 765 mm in the season from March to June, and a minimum of 36 mm in the season from October to December. The other areas from where samples for the study were collected included an abattoir in Kiserian centre of Kajiado County, Kenya and a slaughter slab

with estimated over 2.5 million people.

**40**

Each of claws collected from the abattoir and the slaughter slab was thoroughly washed. Observation of gross appearing lesions was done. Each lesion/abnormality was recorded in data collection sheets. Each claw was radiographed in dorso-palmar or dorso-plantar views. The radiographs were viewed and examined thoroughly. All radiographic changes seen were recorded. Owing to the time lapse between slaughter and examination, the claws were partially desiccated by loss of their water content, making trimming difficult. Therefore, after radiography, the area covered by the horn capsule was dipped in water for 2–3 h to make them softer for facilitation of trimming. Trimming was done by removing 2–3 mm of the horn of the sole, while observation of any lesion on the sole was made. All lesions were recorded. About 10 claws with subclinical laminitis and another 10 claws with chronic laminitis were purposively selected. Sagittal sections of all these 20 selected claws were done starting from the fetlock joint level through proximal, middle and distal phalanges. All gross lesions observed in the exposed corium and the phalanges after sagittal section were recorded.

The horn of the sole was removed from each claw using a knife to expose the corium of the sole fully. Sections of about 5 mm thickness of the corium specimens were harvested in transverse and longitudinal planes from each of the claw samples. The corium specimens were further sectioned into 1–2 millimetre pieces, which were dehydrated using ascending concentrations of absolute isopropyl alcohol, that started from 80 to 100%. Clearing of the tissues was done in xylene, then embedded in paraffin wax, blocked on wooden chunks, followed by fixing on the microtome. The tissues that were in paraffin wax blocks were cut into 5 μm thick pieces. From each block, four pieces of 5 μm thick tissues were made. This was followed by dewaxing the tissue sections in xylene and hydrated using graded alcohol whose concentration was from 100 to 50%. It was cleared in xylene, alcohol and washed in water. The tissues were stained with haematoxylin and eosin (H&E). Following dehydration, they were mounted on microscope slides and cover slips with Destrene 80, dibutyl phthalate and Xylene (DPX) mountant according to Ref. [25]. The slides were examined under light microscope using ×10, ×40 and ×100 objective lenses. The results were recorded and photomicrographs taken as necessary. The control in this study was done by comparing the findings in the normal claws with those that had lesions or were abnormal. The corium samples from claws that did not show signs of subclinical or chronic laminitis were processed using similar procedure as the test specimens and used as controls.

#### **3.5 Data management and analysis**

Claw lesions were given numerical codes for ease of entry into the computer. The prevalence of claw lesions was computed using Microsoft Office Excel data

analysis tool as the number of dairy cow abattoir feet/claws showing a specific type of lesion divided by the total number of feet/claws examined multiplied by 100 to make it into percentage. Percentages of occurrence of radiographic changes were calculated by dividing the number of claws showing a specific radiographic feature by the total number of claws examined through radiography multiplied by 100. The percentages of histopathologic changes were calculated out of the number of claws with subclinical laminitis and chronic laminitis selected for histological evaluation.
