Effect of change in body weight and condition during the dry season on capacity for work of draft oxen

Assessment of Phenotypic Characteristics and Work Suitability for Working Donkeys in the Central Highlands in Kenya

The study aimed to assess the phenotypic characteristics of donkeys and their suitability for work. Data were collected on age, sex, coat color, height at withers, body length, and heart girth from 360 randomly sampled donkeys raised in a highland agroecological system in Kenya between the months of June and September 2018. Data were analyzed using descriptive statistics and ANOVA with the sex of the donkey and age group treated as sources of variation. The weight of donkeys was estimated using a formulae incorporating body length and heart girth. The study reveals that the average weight of the working donkey in the central highlands of Kenya was 155.5 kgs ± SE 1.71. Their height at withers was 99.7 cm ± SEM 0.50, with a heart girth of 113.7 cm ± SEM 0.43 and a body length of 113.2 cm ± SEM 0.58. All these body measurements varied significantly by sex and age group (P < 0.001). Therefore, donkeys raised in Kenya had the same height but heavier, with longer body lengths and heart girth measurements when compared to other domesticated working donkeys in different parts of the world indicating genetic diversity, differences in ecogeographical conditions and husbandry practices. The majority (86%) of the donkeys were in good welfare conditions with moderate to ideal 86% body condition scores, minimal body lesions 5%, and lameness 18%. The results are useful for extension agents and donkey users when estimating optimal pack or cart loads in line with their welfare. The findings provide opportunities for future research on the reasons for phenotypic diversity between donkeys raised in Kenya and other parts of the world.

The donkey as a draught power resource in smallholder farming in semi-arid western Zimbabwe: 1. Live weight and food and water requirements

Three experiments were undertaken to assess the Zimbabwean donkey. In the first study, 191 male and 144 female working donkeys from Matopos, Nkayi and Matobo districts were weighed. Age, sex and coat colour were recorded and heart girth, umbilical girth, body length and height were measured. There were no differences (P > 0⋅05) in live weight, 142 and 141 kg, heart girth 115 and 115 cm, body length 89 and 90 cm and height 105 and 105 cm between males and females. This suggests that draught potential might be similar between the sexes. Heart girth was the best single predictor of live weight: live weight (kg) = heart girth (cm)2⋅83/4786 (R2 = 0⋅86). Donkeys were similar in size to others in Africa. In the second study, the voluntary dry-matter intake (DMI) of a poor quality hay was measured for 35 days in nine male (mean live weight 150 kg) and nine female donkeys (142 kg) allocated to one of three treatment groups: water available ad libitum, or given every 48 h, or every 72 h. There were significant differences in daily water (P < 0.001) and DMIs (P < 0.05): 8.5, 4.9 and 5.1l and 3.1, 2.8 and 2.7 kg for the three treatment groups, respectively. However even with restricted access to water, donkeys maintained a relatively high DMI. In the third experiment a 3 Х 3 Latin square was designed with three teams of four male donkeys each, either working (5 h/day) I no access to food (5 h/day); not working/no access to food (5 h/day) or not working/access to food 24 h/day, for 63 days. For working and non-working donkeys, there were no significant differences (P > 0.05) in DMI, DM apparent digestibility and mean retention time (MRT) of hay. Time of access to food did not influence DMI. The apparent lack of response was attributed primarily to the poor quality of the hay.

Performance and management of draught animals in agriculture in sub-Saharan Africa: a review

Use of animal power generally enables farmers in sub-Saharan Africa to increase agricultural production and improve the quality of life. Effective use of working animals depends on an understanding of the capabilities of the animals for work, their husbandry requirements and the factors which can influence their performance. These issues are reviewed in this paper in the context of the use of animal power in agriculture in sub-Saharan Africa. The type of animal used for work determines power available to the farmer. The performance of donkeys, horses and cattle have been compared in work tests. Equids are more suited to rapid low draught activities where their faster speed can be used to advantage. At higher draught forces, where speed is less important, the additional weight and power of cattle are an advantage. Use of heart rate recovery after work gives a reasonable indication of fatigue and fitness of equids, when test conditions are standardized. Although feed requirements for work are generally low, feed quality can be so poor that animals are unable to eat enough to meet energy needs for work, and so lose weight during the work season. However, improvements in work performance are not always seen following supplementary feeding in the dry season and the economics need to be considered in each case. Food availability, diseases and heat stress, the major constraints to performance of draught cattle and donkeys working in sub-Saharan Africa, are discussed.

Performance of draught cattle in communal farming areas in Zimbabwe after dry season supplementation

Sixty-four pairs of oxen owned by smallholders were randomly allocated to one of 3 supplementary treatments offered at one kg per head per day from July to October or to a control where no supplement was offered. The supplements were maize stover plus silverleaf hay (2:1 w/w), urea-treated maize stover (50 g urea/kg stover) and plain maize stover. Animals fed plain maize stover or no supplement lost weight (6 to 7% of initial weight), whilst those fed the other 2 supplements maintained their liveweights. Supplementation reduced time spent on feeding activities by 10 per cent. Animals fed on urea-treated maize stover or maize stover plus silverleaf hay ploughed at speeds that were 29% faster than oxen on the other treatments and covered 45% more area. Blood parameters indicated a general deficiency of nitrogen intake throughout the dry season. It was concluded that supplements of good quality have the potential to improve the working ability of communal area oxen.

Improving feeding management and work performance of Mashona oxen through strategic supplementation with cobsheath-groundnut stover

Six pairs of Mashona oxen ploughed dry, red clay soils in August (winter) and in mid-November (spring). Between September and November the oxen were randomly assigned to 3 feeding groups: no supplement (control), 400 g/head per day of cobsheath-groundnut stover for 70 days and 800 g/head per day of the same supplement for 35 days. Cobsheath-groundnut stover was fed in order to determine its potential as supplementary feed for draught oxen during the dry season. The liveweight (LW) lost by heavy oxen during winter ploughing was lower (P < 0.001) than that of light oxen. During spring ploughing heavy oxen again lost less (P < 0.001) LW than light ones. In addition, non-supplemented oxen lost more LW than those supplemented. Therefore feeding strategies for Mashona draught oxen should aim at providing adequate nutrients to at least maintain LW during the dry season. Heavy oxen outperformed (P < 0.001) light ones during winter ploughing. Work output of supplemented oxen in spring was also significantly greater (P < 0.05) than that of non-supplemented ones. This result demonstrated the benefits of supplementary feed during the dry season. Concentrations of lactate and free fatty acids in plasma, heart rates and rectal temperatures increased (P < 0.05) markedly during work. The increases were higher (P < 0.05) for light oxen, particularly those not fed supplement.

Effect of liveweight and body condition on work output from draft oxen

A trial was carried out to assess the effect of liveweight and body condition on working capacity of zebu oxen. Over a working period of 9 days, animals which started work with a mean liveweight of 360 kg and body condition score of M+ produced the highest daily work output (3.43 MJ). At an initial liveweight of 360 kg, body condition had relatively little effect on work output, and animals of condition score M- produced a daily work output of 3.19 MJ. In contrast, at a mean liveweight of 310 kg at the start of work, mean daily work output of animals of condition score M+ was significantly lower than that of animals in poorer condition (M-), at 0.81 compared with 2.50 MJ work output per day. It was concluded that body weight as indicated by body size is probably a more useful indicator of likely capacity for work than body condition under the short-season working conditions typical for oxen in the semi-arid zone of central Mali.