Study on management practices and work-associated health problems of draught oxen around Debreberhan, Central Ethiopia

B Urga and T Abayneh*

Faculty of Veterinary Medicine, Addis Ababa University, P.O. Box 34, Debre-zeit, Ethiopia
*current address: Norwegian School of Veterinary Science, Olav M. Troviks Vei 46, H0102, 0864, Oslo, Norway
takele_abayneh@yahoo.com

Abstract

A study was carried out in Werana and Basso districts of North Shewa zone around Debereberhan town, Central Ethiopia to assess the management practices and work-associated health problems of draught oxen through a questionnaire survey and clinical examination of oxen coming to Debereberhan veterinary clinic.

The survey indicated uneven oxen distribution among households with the average being 1.35 oxen per household, which is quite lower than a pair normally required for tillage work. Owing to the shortage of oxen, about 23% of the farmers were engaged in different forms of draught oxen sharing arrangements. The average training age and service life of oxen were found to be 2.8 and 13.8 years, respectively. Average daily work duration and area ploughed were 7.6 hours and 0.38 hectares per a pair of oxen, respectively with a peak work duration of 3.75 months per year indicating seasonal pattern of oxen utilization. On average, a household possesses 2.3 hectares of land of which only 17% was left for pasture, the majority of the remaining land being used for crop production. Of a total of 402 households surveyed, 79 (19.7%) of them responded that their oxen were suffering from one or more of health problems associated with work. Of a total of 543 draught oxen included in this study (both in survey and clinical examination), 84 (15.5%) were found to be suffering from work-associated health problems with major problems observed in their order of importance being injuries of the hump, hoof, leg and whip lashes. Significant difference (X²= 16.16, P<0.01) was observed in the prevalence of work-associated health problems among the different age groups of draught oxen with the highest being in adult oxen (2-8 years old). Daily work duration (X²=15.42, P<0.01)and area of land ploughed (X²=8.54, P<0.01)significantly influenced the occurrence of hump sore (yoke gall) showing direct relationship in prevalence of hump injury and both factors.

Clinical examination conducted on a total of 48 oxen that came to Debreberhan veterinary clinic indicated that 20.8% (10) were found to suffer from work-associated health problems mainly of hump and hoof injuries. Hump and hoof injuries are found to be the major work-associated health problems in the study area with the principal precipitating factors being rough nature of working grounds, narrow and rough bearing surface of traditional harnesses (yoke) and lack of proper care while at work. In general, the study indicated that the potential of the existing oxen population is not efficiently utilized due to several constraints among which are poor management inputs, improper working strategies, poor harnessing design, malnutrition and poor health care.

Key words: Central Ethiopia, draught oxen, management practices, work-associated health problems

Introduction

The use of draught oxen for traction has a long history in Ethiopia, which dates back between1000 and 400 BC. The traditional plough, locally called "maresha", has been in use for the past several centuries and is still in use without any significant changes or developments (Goe 1987).

The main purpose of keeping cattle in the highlands is for draught power, which is estimated to account for about 60% of cattle production by value (Tegegne and Crawford 2000). Out of the estimated 30 million cattle, about 9 to 10 million are oxen, which are used for draught purposes. About 66% of the county's 14 million hectares of cropland is cultivated with the use of animal power predominantly of oxen power. Therefore, availability of oxen at the right time of the year is very critical for crop production and survival of a household in the highlands (Tegegne and Crawford 2000).

Despite the long history of animal traction and huge oxen population in the country, their productivity is generally low. This low farm productivity of the mixed crop-livestock farming systems in the highlands is principally the result of the traditional management practices (Asamnew et al 1988). Moreover, the widespread prevalence of different animal diseases is also among the technical causes of lowered productivity with their multiple dimensions (Abditcho 2002). The potential contribution of draught animal power for an increased food crop production and the country's projected food self sufficiency seemed to be least assessed at present.

The supply of satisfactory levels of draught animal power at the right time for crop production requires sound management of draught animal's throughout the year which include adequate feeding, health care, and appropriate use of animals to ensure their sustained use on farms (Fall et al1997). The use of draught animals is dependent on understanding of the animal's capacity for work, their husbandry requirements and other factors influencing their performance (Pearson and Vall 1998). However, information on the various factors or constraints that lower the performance of draught oxen in the highlands is lacking or not sufficiently explored, which will have considerable relevance in view of envisaging future development strategies.

This study was, therefore, undertaken with the objective of assessing the existing management constraints and to determine work-associated health problems as well as their implication on the performance of draught oxen.
 

Materials and methods

Study Area

The study was conducted from November 2004 to April 2005 in Basso and Werana districts located in the vicinity of Debereberhan town. Debereberhan is located in Central Ethiopia, 130 km North East of Addis Ababa. The area has an attitude of 2780 meters above sea level and is situated at 90 36 N and 39 38 E.

The study area has area coverage of about 150,602 hectares comprising 29 Peasant Associations as well as the 9 administrative units of Debereberhan town. The total draught oxen population of the study area is estimated at 39,120 with human population of 165,176 (Ethiopian Agricultural Sample Enumeration 2001/02)).

Study Animals

A total of 543 draught oxen owned by 402 households located in peasant associations in the vicinity of Debereberhan town were included in this study. Different age groups as well as local and cross breed draught oxen kept under traditional management system were included in the survey while draught oxen coming to the veterinary clinic for various reasons were considered for the clinical examination study.

Study Design

Survey

Questionnaire survey was carried out in a total of 8 randomly selected Peasant Associations from Basso and Werana district. A total of 402 households were randomly selected and interviewed using a structured questionnaire. The questionnaire was designed to collect information regarding oxen ownership, management practices, nutritional status and work-associated health constraints of draught oxen.

Clinical Examination

A total of 48 oxen coming to Debreberhan veterinary clinic for various purposes were subjected to through clinical examination for any work-associated health problems. The finding was recorded in a format prepared for the purpose.

Data analysis

Statistical techniques including averages, percentages and Chi-square test of independence were used in summarizing and analyzing the data. Chi-square test of independence was employed to determine the influence of factors such as age, work duration and area of land ploughed on the occurrence of work-associated health problems.
 

Results

The survey indicated that draught oxen were the principal sources of power for crop cultivation. Bullock or oxen holding size (i.e., number of oxen per household) was not evenly distributed averaging 1.35 per household, which is far below a pair normally required for ploughing. In an attempt to cope up with such draught power scarcity and unequal oxen ownership pattern, about 23% of the farmers were engaged in different forms of draught power sharing and/or hiring arrangements.

Regarding the land holding and use pattern, on average a household possesses 2.3 hectares of land of which only 17% was left for pasture, the majority of the remaining land being used for crop production.

The average training age of young oxen was found to be 2.8 years with the range being 1- 7.5 years with an average training period of about 5 months. Training techniques practiced include hitching a bull with an experienced ox without attaching any implement and then after with gradual exposure to light work until an ox is adapted to hard draught work.

The average daily work duration of oxen pair was found to be 7.6 hours, with the range being from 4 to 11.5 hours, which included some of the hottest parts of the day. Paired oxen plough an average of 0.38 hectares of land per day. Both daily work duration and area ploughed per day were found to vary among the different stages of land preparation with the least being during primary land preparation. The mean peak-working season was observed to be about 3.75 months, which is mainly associated with the cropping season. During this period, oxen spent on work for an average of 59 days.

The maximum service life of oxen averaged 13.8 years. The sources of replacement oxen in the area were through purchase and replacement household herds.

In a survey made to determine the occurrence of work-associated health problems, 79 (19.7%) households reported that one or more of their oxen were suffering from one or more of work-associated health problems. Of a total of 543 draught oxen owned by the 402 households included in the questionnaire survey and clinical examination studies, 84 (15.5%) were found suffering from work-associated health problems with major problems in their order of importance being injuries of the hump, hoof, leg and those arising from whip lash (Table 1).

Of the total 84 draught oxen suffering from work-associated health problems, 54 (64.3%) were adults (2-8 years), 9 (10.7%) were less than two years old and the rest 21 (25%) were older than 8 years. Work-associated health problems were found to significantly differ (P<0.01) among the different age groups of oxen with the highest prevalence being in adult oxen (Table 2).

The prevalence of hump sore (yoke gall) showed direct relationship with work duration and area of land ploughed per day with significant differences being observed among the different categories of work duration and area of land ploughed (Table 3 and 4).

Of the total of 84 cases of work-associated health problems, 61.9 % (52) of them occurred during the wet season while the rest 38.1% (32) were during the dry working months of the year.

Clinical examination made on a total of 48 oxen indicated that 20.8% (10) were found to suffer from work-associated health problems the main problems identified being hump and hoof injuries.

Discussion

Draught oxen, being the main and only sources of draught power in the highlands of Ethiopia, play a crucial role in crop production. Consequently, in the highland areas availability of oxen at the right time of the year is very crucial for crop production and hence, the livelihood of a household (Gryseels and Anderson 1983). Although a pair of oxen is normally required to carryout out the normal task of ploughing, oxen ownership patterns were not evenly distributed in the study area mainly due to differences in the economic status of the households. The average oxen holding size per household (1.35) observed in this study is higher than the 1.09 holding size recorded in North Wollo, Northern Ethiopia (Wilson et al2002). The oxen holding size, which is lower than a pair, is the main reason for considerable proportion of households to engage in draught oxen sharing and/or hiring arrangements observed in the study area so as to cope-up with the unequal oxen distribution. Such traditional arrangements may actually give the opportunity for resource limited farmers to have access for draft oxen power although with negative influences on planting time and cultivation operations (Tegegne and Crawford 2000). The use of other species of draft animals particularly of donkeys could be alternative cheap sources of draught power for secondary or tertiary tillage operations to partly alleviate such draught oxen shortages (Abayneh et al 2002).

The average training age of 2.83 years recorded in this study is much lower than previous reports of 4.3 years in the high lands of Ethiopia (NEDECO/DHV 1998 as quoted by Wilson et al2002). Since training time is a function of body weight and physical development (Leegwater 1998), the observed difference may be due to the wide spread utilization of F1 cross breeds (Friesian x Zebu crosses) that have faster growth rates (quicker physical development) than indigenous zebu breeds in the study area (Gryseels and Anderson 1983). The relatively earlier training age observed in this study may be responsible for the long average maximum service life of oxen recorded in this study (13.8 years).

The average daily work duration obtained in this study (7.6 hrs) is higher than the reports of a similar study in Tigai, Northern Ethiopia, where the actual average daily work duration was found to be only 4.7 hours per day excluding the time elapsed due to frequent stoppages at the end of each furrow during tillage (Wilson 1975 as quoted by Wilson et al2002). The higher daily work duration observed in this study may thus be due to the fact that such time elapses were not excluded. Hence, the actual work duration is expected to be much lower than the current figure if such time elapses were considered.

The working time for oxen that included some of the hottest times of the day may contribute to the limited performance of oxen due to heat stress. High muscular temperature of 44-45^oC due to heat stress is known to induce rapid onset of fatigue due to neuromuscular disorders leading to slower work rates (Fall et al 1997). Such adverse effects of climatic stress can adequately be prevented by using oxen for work during early and late hours of the day, when the daily ambient temperate is the lowest. Sprinkling with water may also be considered to assist in delaying fatigue and early recovery from work stress (Upadhyay 1989).

The seasonality of work in draft oxen observed in the current study is a similar finding in previous works in other parts of the country, which is mainly associated with the cropping season. Such seasonality of work predisposes draught oxen to work stress whenever they are called for work after a long period of idleness. The effect of stress will make them more vulnerable to a variety of health problems. Using oxen for other types of draught operations outside the cultivation period can keep them exercised and efficiently utilized year round and thus may help to prevent the negative impact of seasonality of work (Pearson and Vall 1998).

The scarcity of grazing resources observed in the study area is another factor limiting the performance of draught oxen. This is due to the increasing demand for more cultivable land and the resulting higher stocking rates on the available grazing resources or pasture areas. Although oxen generally receive priority in supplementary feeding of hay and crop residues, the amount and quality of feeds available does not seem adequate to meet their requirements. This may be compounded with sub-clinical diseases and presence of internal and external parasites. Draught oxen are thus usually debilitated at times of the year when they are called upon for work. This further reduces their already limited power output (Wilson et al2002).

In addition to suffering from health problems common to other livestock, draught animals (oxen) suffer from specific heath problems associated with work (Sastry et al 1986). Among the injuries sustained by draught oxen in association with improper management, hump injuries are major causes of ill health. Deeper injuries might also arise from narrow bearing surfaces of harness and excessive pressure exerted by the weight of load for prolonged periods on the hump leading to blockage of normal blood supply of the underlying tissue (Payne 1990). The higher prevalence of yoke injuries observed in this study is thus attributable to the poor harnessing system and improper working strategies practiced in the area. The use of unpadded rough wooden yokes, improperly fitting yokes and pairing of oxen with different physical characteristics may be the principal factors that could be incriminated for the occurrence of work-associated health problems mainly of hump injury in the area. Moreover, over-work, sudden return to work after long periods of idleness (seasonality of use) and improper management of young oxen on their first exposure to work may also be the reasons for the considerable occurrence of hump injuries recorded in this study.

The significantly higher occurrence of hump injuries with an increasing work duration and area of land ploughed obtained in this study may be due to prolonged duration of sustained pressure and high friction imposed on the hump by the rough and narrow bearing surface of the yoke.

The differences observed in the distribution of hump injuries in wet and dry working seasons may be due to the higher intensity of work associated with cropping season and the wetting of the hump during the rain resulting in high frictional force between the harness and the hump leading to injuries.

Abrasions arising from improper harnessing may have several serious consequences including being a suitable site for establishment of various infectious agents (Radostitis et al1994), reducing the working performance of oxen (slower rates of work) and if sever enough cause loss of animal days at work. Moreover, the way draught oxen suffering from hump injuries are handled further complicates the problem. It is not hard to imagine the unbearable pain and suffering such animals face if made to work without fully recovering. Traditional beliefs that prevent farmers from seeking medical help to their oxen, failure to give early attention for the problem, short periods of rest and consequent premature return to work are responsible for exacerbating the effect of hump injuries. Generally, not to cause discomfort or injury to the animal, harnesses should have a good fit to the animal, be smooth shaped or padded (Fielding and Pearson 1991) and individually made (for a particular animal) with adjustments to accommodate body condition changes. The latter also helps in preventing the transmission of certain skin diseases.

Other work-associated injuries observed such as whip injuries are due to improper handling by inexperienced or aggressive operators while those of hoof injury may be attributed to working in rough and slippery grounds. Hoof injury can be prevented through regular shoeing of draught oxen if they are to be used on hard ground. Shoeing is one of the important husbandry activities in a draught animal management system that helps to prevent the splitting of horny cover and undue wear. It also provides additional grip while walking (Kumaravelu et al 2004).

More information related to the control of health problems specific to draught animals as well as problems to which draught work acts as a predisposing factor need to be explored through further research to enable design strategies for an efficient utilization of draught oxen in smallholder farming systems.
 

Conclusion

This study indicated uneven oxen ownership pattern among households with the average being less than a pair, which is normally required for ploughing.

Although draught oxen are indispensable sources of power for the agricultural sector in the study area, their utilization is generally inefficient due to several factors among which are poor management inputs, malnutrition, health constraints and seasonality of work.

Hump and hoof injuries are found to be the major work-associated health problems in the study area with the principal precipitating factors being the narrow and rough bearing surface of the traditional harness (yoke), rough nature of working grounds, and lack of proper care while at work. Generally, once such injuries occur they are given little attention and farmers keep on using their oxen for work, which further worsens the condition leading to deeper wounds requiring long periods of recovery.

Therefore, the harnessing device, oxen management (nutrition, health care, breeding and working condition), other alternative sources of draft animal power, awareness of farmers to health problems arising from improper use of oxen, are some of crucial issues that need to be considered in an attempt to increase draft animal power availability or improve the efficiency of draft animal power utilization for crop production in the central highlands of Ethiopia.
 

Acknowledgements

The authors would like to acknowledge the staff of Debreberhan veterinary clinic for their technical support and the farmers/households for their kind cooperation during data collection.
 

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