Cover Image
close this book Animal traction
View the document About this manual
View the document About the author
View the document Acknowledgments
close this folder 1. Introduction
View the document What is animal traction?
View the document History of animal traction
View the document Why use animal traction?
View the document Some considerations
View the document How can animal traction be used?
View the document Before beginning: what do you need to know?
close this folder 2. Draft animal selection
View the document Popular draft animals
View the document Determining power requirements
View the document General rules concerning power requirements
View the document Method for determining size of the hitch
View the document Determining weights of animals
View the document Selection of individual draft animals
View the document Conformation
View the document Temperament
close this folder 3. Animal husbandry
View the document Sheller
View the document Nutrition
View the document Grooming
View the document Minor medical problems and first aid
close this folder 4. Training draft animals
View the document Before training begins
View the document General comments on training procedure
View the document Training cattle
View the document Program for training cattle
View the document Training horses, donkeys and mules
View the document Program for training horses, donkeys and mules
close this folder 5. Yokes and harnesses
View the document Yokes and harnesses for cattle
View the document Yokes and harnesses for horses, donkeys and mules
View the document How to harness a horse, donkey or mule
View the document Steering systems
View the document Breeching harness
close this folder 6. Hitches
View the document Safety rules
View the document Implement hitches
View the document Vehicle hitches
View the document 7. Field operations and implements
close this folder 8. Economic and technical assistance
View the document Farm planning assistance
View the document Equipment options
View the document Credit for equipment
View the document Credit for animals
View the document Procedures and controls
close this folder 9. Animal traction extension
View the document Extension education
View the document Appendix A: Animal power
close this folder Appendix B: Animal nutrition
View the document Energy needs: bovine animals
View the document Energy needs: equine animals
View the document Nutrient needs of draft animals: protein, minerals, vitamins
View the document Feeds and feed composition
View the document Calculating a ration
View the document Recommended rations and feeding practices
close this folder Appendix C: Disease recognition and control
View the document Parasites and parasitic disease
View the document Appendix D: Workshop and spare parts inventory
View the document Appendix E: Animal traction instruction forms
View the document Appendix F: Animal breeds used for power
View the document Bibliography
View the document Resources
View the document GIossary

Appendix A: Animal power

The formulas below can be used to approximate the size of the hitch (animal or animals) which will supply the desired amount of power. "W" is the weight of a single animal, "d" is the draft requirement (this is taken from the chart), and "c" is the animal's power coefficient. For a bull, "c" is 8 or 1/8 of W); for a donkey, it is five (or 1/5 of W). If animals will be working new or hilly land, or will be harnessed in yokes ratner than collars or breastbands, coefficients should be increased to 9 or 10 for bulls, 6 or 7 for donkeys.

The first two formulas (below, A and B) are used to calculate the weight of animals that will be used alone; the other formulas allow for the losses of efficiency that result when multiple hitches are used.

Assuming a farmer needed draft unit that supplied a tote" of 57 kg of force, the following calculations would be made.

W = (57 x 8)/1.85 or W = 246

or, each of two bulls would have to weigh 246 kg. (Note that, used alone, this animal will supply 1/8 x 246, or 30.8 kg draft. In a team of two, it is 7.5% less efficient, supplying only 28.5 kg draft-or half of the 57 kg needed.

A One bull

W = 1/8 d

B One donkey

W = 1/5 d

C Pair of animals

W = dc/1.85

D Team of three animals

W = dc/2.55

E Team of four (tandem pairs)

W = dc/3.12

F Team of five

W = dc/3.5

G Team of six

W = dc/3.78

W = (57 x 5)/1.85 or W = 154

If the farmer could not buy or obtain a pair of bulls, the donkeys might be a practical alternative. However, donkeys work only 3-4 hours per day, so the farmer might consider buying two pair and working them in separate morning/afternoon shifts. If the doneys in the area were of a small breed, it might take three or four animals to deliver the necessary power:

W = (57 x 5)/2.55 or W = 112

or each of three donkeys would have to weight approximately 112 kg. Or

W = (57 x 5)3.12 or W = 91

or each of four donkeys would have to weight about 90 kg if the draft requirement of 57 kg were to be met.