|
|
| The Context |
|
Who?
When?
Where?
|
Tsetse flies are endemic in much of Africa and are responsible, through their bite, for the spread of the deadly disease trypanosomosis. Controlling tsetse controls the disease but the availability of drugs for prophylactic or advanced protection is sometimes poor. Where they are available, their erratic use can lead to the development of resistant strains of the trypanosome so the drugs become useless. They can also cost the earth so that poorer farmers can't afford them!
Typanotolerant breeds of cattle, such as the N'Dama, offer an alternative to smallholder farmers, but the productivity of these cattle, when infected, maybe low or variable. Good feeding can help the ability of cattle to tolerate infection through the control of anaemia - an inevitable consequence of trypanosome infection. This means that infected animals can stay productive.
Making the right decisions on when to use drugs or better feeding is essential but not always easy. |
- Do I use drugs to combat the infection ?
|
|
- Do I supply better feed,
and do my animals need
more feed or better quality feed ?
|
| Methods |
| A Decision Tree will help |
- Using drugs or finding the right feeding system under different levels of tsetse challenge and physiological states, requires an understanding of the interactions between body condition and short-term feeding inputs. This is very complicated for farmers and so scientists have developed a decision tree to help them pick the best approach.
- This involves firstly dividing the disease risk to animals into high, medium or low threats. A management and feeding strategy is then chosen based on the farmer's production objectives for the best control of trypanosomosis.
|
| |
High Risk
High-risk threats mean animal's life are in danger and thus the decision tree encourages farmers to use drugs (like berenil) if available and feed oilseed cake to aid recovery.
If drugs are not available then animals need to be withdrawn from work or grazing and fed a high protein level:
0.5kg sesame or groundnut cake/day
1.0 kg cottonseed/day
2.0 kg groundnut hay/day
|
| |
Medium Risk
Animals will survive medium threats but production will be affected. The strategy here must therefore reflect farmers' production aims. If the animals representa family's savings or a source of manure then no further action need be taken with typanotolerant breeds like N'Dama as they will eventually recover.
If the animals are used for draught or milk (or pregnant cows) and drugs are available then they should be given. If not then they should be feed the high protein diet as for high-risk threats (above). Draught bulls should also be rested if possible. Milk animals will probably lose weight and milk yield but their calf should survive.
|
| |
Low Risk
The approach for animals kept for manure or savings is no action.
For working animals it is recommended that animals continue working unless they show signs of stress. Feeding groundnut hay will help stabilise the disease and aid recovery.For pregnant cows the value of the calf will usually exceed the cost of using drugs so their use is encouraged. For milking cows drug use is recommended or feeding the high protein diet if not.
|
| Some Examples |
In The Gambia, Trypanosoma congolense-infected N'Dama cows, grazing native pastures and crop residues can loose twice as much weight as uninfected cows during the dry season. Feeding just 2 kg of groundnut hay/day to the infected cows can significantly reduced this weight loss. The feed intake of bulls used for draught also changes depending on how serious the infection and what diet is offered. Working and non-working animals will eat more when a higher quality component such as groundnut hay is included. Once animals get infected however intake goes down and you need to feed more protein such as sesame cake. In mild infections this significantly increases red blood cell replacement and reduces anaemia so allowing the draught bulls to keep working. Feed supplementation is thus a useful way to counter the effects of the disease where drugs are unavailable. |
| Support and Resources Required |
Supporting the poorer farmers when they first use this decision tree is likely to be in important part of its long-term acceptability and success. With decreasing access to state veterinarians the task of supporting such livestock keepers will fall to either commercial advisers, paravets or NGOs. Once farmers becomes proficient in using the tree effectively they will gain confidence to use it unaided and be willing to pass expertise to family and friends. |
| Costs and Benefits |
Being able to make the right decision when faced with trypanosomosis is vitally important to the livelihoods of resource poor farmers. Using the decision tree effectively will mean more and healthier stock and thus extra milk, manure or work. This can be used to benefit the family enterprise and livelihood and hence improve smallholders' income, investments and capital.
The costs of using this decision tree lie in making the wrong decisions. It may also encourage more drug use and thus increased costs. Using better feeding and management strategies should however provide surpluses of produce. |
| Risks |
The risks of using the decision tree are greatest when a farmer is initially unfamiliar with how it works and make mistakes. This will mean that he or she may lose confidence in its ability to help him. |
| Alternatives |
There are few alternatives to either drug use, supplementary feeding or the use of trypanosomosis tolerant breeds. Although feed supplements alleviate weight loss in infected cows during the dry season, supplementation with better quality forages such as groundnut hay may not be enough to improve to avoid drug use when cattle become infected during the stressful working period. |
| Impacts |
This decision tree has the potential to be of great benefit to a large number of poor farmers living in trypanosmasis infected areas of Africa. By helping farmers achieve the most effective use of their limited and scarce feed and financial resources surpluses can be used in generating more income and improving family livelihoods. Cost-effective feeding and management programmes will increase productivity of cattle both with and without disease. This will greatly contribute to the improved sustainability of smallholder farming systems in tsetse-endemic areas of West Africa, where livestock are integrated into the farming system. |
| Policy Implications |
If drugs are available they should be used in cases of high to medium trypanosomosis risk for animals used for work or for milk. If drugs are not available then supplementary feeding will help stabilise animals against the disease but work performance, milk yield or growth may still suffer. Providing farmers with access to information that will help support these decisions is as important as provision of drugs. |
|
| Research Findings |
Management strategy Decision Tree for three levels of
Trypanosomosis risk in trypanotolerant cattle |
|
|
|
|
|
|
| References and Further Reading |
|
| Related Research Projects |
This information is part of a series on small stock that cover disease-nutrition interactions.
| R6140 |
Controlling trypanosomosis in Sheep & Goats is more important than extra feeding |
| R6342 |
Best Feeding Practices to help animals fight Trypanosomosis |
| R6358 |
The Decision Tree that Helps counter the threat of Trypanosomosis |
| R6561 |
Helping lambs to control stomach worms before they get sick |
| R6608 |
Feeding Tree Fodder to beat liver Fluke |
| R7424 |
Farmers can use Tannins to kill parasitic worms |
| R8151 |
Sensible use of drugs and feeding to stop roundworms killing sheep & goat |
|
