Recent advances in research on draught ruminants

A feeding system, draught cows, disease/work interactions and animal power introduction in a fanning system, four areas of recent research on draught ruminants which am important to future development of animal power, am revi ewed. A new feeding system for draught animals is described which enables f ood requirements and fire effects of work on live weight and milk productio n to be calculated. Recent data on the energy cost of walking ave appraised. Research on workin g cows, mainly in Ethiopia, has shown that undernutrition has a greater eff ect on milk yield than work, which has a transient effect. The length of th e post partum anoestrous period increases with decrease in body condition. Body-weight loss increases with increasing work lend. If is suggested that dairy cows delay conception by 1 day for Every day of work done. Work has l ittle effect on food intake or digestive parameters. Although it is associa ted with an overall inn case in food intake of cows, even of un-supplemente d forage diets, the increase is not sufficient to meet all the extra energy needs for work. Food intake of both working and non-working cows increases during lactation. Disease limits the working capacity of draught animals and work can exacerb ate disease. These effects were investigated using Trypanosoma evansi in In donesia and T. congolense in The Gambia. In both studies, infected animals were able to do much less work than non-infected ones and the severity of t he Effect depended greatly on the strain of trypanosome used. In general, i ncreasing the plane of nutrition did not ameliorate the effects of the dise ase, nor in the Gambian study did it prevent loss of appetite in infected a nimals. The technical and agronomic innovations necessary for the introduct ion of animal pou,er into an inland valley region of central Nigeria are de scribed and some of the sociological implications discussed.