In-depth knowledge of the factors influencing the work achieved by animals is re- quired. Some of these can be controlled by farmers, others cannot (Fig. 1.13).
Environmental Conditions
Environmental factors (soil and climate) that define working conditions are uneasy to control. Farmers can improve such conditions but to a small extent. They may prefer to work their animals at the beginning or end of the day, when heat is acceptable. This is profitable in terms of animal capabilities and endurance.
Figure 1.13. Factors influencing the capabilities of animal teams.
Choice of Animals
The characteristics of animals (breed, species, sex, age, temperament) determine their working abilities. Farmers cannot control these. Their only room for maneuver is in the choice they can make between the various species locally available or affordable. Heavy and slow species (e.g., elephants, buffaloes, bovine crosses) must be preferred for hard work. Light and fast species (e.g., donkeys, horses, camels) are particularly suited for light work such as sowing, weeding and transport. Whatever the species, local breeds
are preferable. In terms of draft, the cows potentialities are almost the same as those of oxen. Nevertheless, cows are less convenient for high draft forces.
Use of Animals
Team composition and the choice of implements and harnessing systems depend on the farmer’s decisions. They are key factors for transforming the energy accumulated by animals into mechanical power. With current yokes and harnessing, pooling two animals or more in a team results in a reduced efficiency at an individual level. If the available power is 1 with one animal, it is only 1.85 with two animals, 3.10 with four, and 3.80 with six [12]. Choosing the more suitable harnessing system, equipment and number of animals depends on local availability and cost, but may rapidly enable significant energy gains.
The main harnessing systems have been largely described in many manuals and books [3, 4, 6, 9, 10, 16]. A harnessing system is a set of elements involving a harness, driving fittings (steering ropes, bridles) and single or multiple hitching systems (abreast or in tandem). For carting, additional fittings can be used to assume other functions such as the cart balance (back strap, belly strap), braking, and reversing (breeching strap).
The harness is the main part of a harnessing system. It makes it possible to optimize the energy potential provided by an animal to exert a force for pack transport, pulling a cart or a farm implement, or driving an animal-powered gear. There are various types of harnesses that can be classified according to the point where they apply work to the animal, e.g., before the shoulders (collar), on the withers (withers yoke), just behind the horns on the neck (neck yoke) or on the breast (breast band or breast strap) (Fig. 1.14).
The collar generally is the most suitable harnessing system. A collar includes a frame for fitting on the animals, padding for protection and comfort, and a device for hitching an implement. There are several points to apply a collar to the animal, which results in a better distribution of forces. Collars are not as widely used as expected because they are relatively difficult to make, and therefore expensive.
Breast bands are lighter and simpler harnesses, widely used with horses and mules because of their simplicity and low cost. They prove well-suited to the conformation of such animals because of their ample breast.
Yokes are mainly used with bovines. They take power from points higher on the animals than collars and breast bands. According to the number of animals harnessed, yokes can be single with a single animal, double with a pair of animals, or sometimes triple for training a young animal between two older ones.
Head yokes described as forehead yokes are tied in front of the horns, and are rather uncommon. They were known in Spain and largely popularized in Switzerland and Germany. Head yokes described as neck yokes are tied just behind the horns. They were widely used in Europe before the introduction of power-driven equipment. Mainly used with humpless cattle (Bos taurus) with strong necks and horns, their form varies from the simplest uncarved wooden pole to yokes shaped into more or less pronounced bows.
Padding is required between the yoke and the animal’s neck. Incorrectly shaped or fitted neck yokes, with excessively loose or thin securing ropes, provoke injury, horn wearing and sawing. This results in reduced power from the draft animals harnessed.
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In Burkina Faso [9] and India [15], the use of improved yokes has made it possible to achieve respective energy gains of 15% and 15%–25% as compared with traditional yokes.
Withers yokes apply on the withers, in front and over the shoulders. They are naturally suited to hump cattle (Bos indicus) such as zebus. They can also be used with taurines as N’Damas. Withers yokes are predominant in Africa.
Whatever the type of yoke, lowering the attachment point also requires lowering the applying points towards the points of the shoulders. This reduces the slope of the line of draft (an angle of 15◦is suitable).
Livestock Management
The components of livestock management (i.e., feeding, training, care, and watering) depend entirely on the user. They determine the conditions and steadiness of the working animal, resulting in the actual energy accumulated and available for working with respect to the energy potential of the species.
Feeding must cover the nutritional expenditures that allow animals to maintain their weight. To produce work, milk or meat, and for their maintenance, animals require en- ergy, proteins, minerals, vitamins and water. The energy contained in feeds is called gross energy, 25%–55% of which is lost in feces. The remaining energy is called digestible energy. This undergoes losses as gas, urine and heat, and leads to the net energy used by animals for their maintenance, for working and sometimes also for other produc- tion.
Stock watering is of prime importance to counterbalance the water losses induced through the respiration and transpiration processes occurring when an effort is exerted.
Water quantities must be determined according to the work required and climatic con- ditions. They can easily double. The minimum is 15 liters of water for an ox weighting 300 kg, performing a light work, in the rainy season, and a daily feed ration of DM (dry matter) 4–5 kg [3].
Timeliness in vaccinations and other health treatments (e.g., parasite control) are also beneficial, although farmers can only use the products available locally.
The training level will affect animal performance at work. Docile animals, which prove easy to handle and steady in the force required, will be more efficient. A training program consists of a succession of stages based on repeated commands and constraints to one or several animals, so as to achieve a docile and firm behavior at work. Training will preferably be done before the agricultural campaign, when animals are about three years old. Duration depends widely on the animals’ age and temperament, and on the trainer’s skill as well. Training time ranges from one month with already familiar animals to more than two months with animals not used to human company.
There are three methods for training cattle:
1. Hitching two young bulls together with the same yoke. This is the most common, but the more difficult, method.
2. Training a young animal with an older one for one or two weeks before they are yoked together. The advantage is reduced stress for the young animal because of the example offered by the older one.
3. Yoking three animals together, with the young animal between two already well- trained animals. This is certainly the most rapid training method with vicious, nervous and restive cattle. It is widely employed in southeast Africa.
The future user must train draft animals personally, or at least take an active part in the training. The first stage is a mutual familiarization. The trainer must show patience, calm, sympathy and firmness. Further stages involve putting the yoke on the animal and making it accept the yoke, and training the animal to walk and pull a light load, exert a tractive force, pull farm implements and work alone.