Mr. Eng-Leong ("Jacky") Foo
I would like to thank the author, Prof. I. Aini, for her paper which provided information on the variety of diseases that rural family chickens may have.

Chickens have been around for some thousands of years and I wonder if there is any genetic changes/adaptations in them regarding disease resistance. Do village chickens change their diet when they are sick; i.e. are they clever enough to look for certain plants which will cure them? (as they might do in a Disney movie!)

From the paper: "Village chickens are known to be susceptible to most diseases which affect commercial chickens."

The living conditions of commercial chickens are certainly different from that of village chickens. Is there a group of diseases that are predominantly associated to commercial chickens and not with village chickens?

From the paper: "Due to free-ranging and unconfined type of management, disease control is very difficult and expensive, thus is rarely practised by the villagers (Aini, 1990)."

Given this condition/situation, what is the mortality rate of village chickens in Malaysia? Even though you may say that there is limited data from villagers, they do have experience that form the basis of their skills in raising village chickens. What do they say for a normal flock of village chickens?

From the paper: "The other common diseases reported in village chickens are: infectious bronchitis, fowl pox, fowl cholera, infectious coryza, Marek's disease, lymphoid leukosis, pullorum, chronic respiratory disease, infectious bursal disease, aspergillosis and coccidiosis. Other health problems include those caused by endoparasites, ectoparasites, haemoprotozoa and to a lesser extent, microfilaria (Aini, 1990)."

Are any of these diseases transferred from egg (contamination on the egg shell, egg in itself?) to the chicks so that even if a chick is isolated from all other chickens, the disease is already there?

Please excuse me for asking these basic questions which may already be answered by earlier research. It is just that Prof. Aini's paper gave me the impression that the decades of research and practice have not successfully provided an economically viable package for villagers.

From the paper: "Poultry farmers share the common view that unless Newcastle disease is effectively controlled, all efforts to increase production of village chickens will be wasted. ..."

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Dr. Saka Saheed Baba
sympathize with the common view of poultry farmers as appropriately stated by Prof. I. Aini in her Lead Paper 2 that "poultry farmers share the common view that unless Newcastle disease is effectively controlled, all efforts to increase production of village chickens will be wasted ..." By achieving a sustainable control of Newcastle disease among the scavenger poultry populations, 40-50% of the goal of improving the productivity of this group of birds would have been realized.

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Drs. Robyn G. Alders and Raul Fringe
We agree completely with Prof. I. Aini's observation that the control of Newcastle disease (ND) is the starting point for interventions focusing on village chickens. Farmers whose only livestock is village poultry tend to be resource-poor and must, therefore, be confident of making a return on any extra investments.

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Dr. Jonathan G. Bell
Thank you very much Dr. Aini for the comprehensive overview of the disease situation in South East Asia. You mention that in most areas control of diseases is either lacking, very minimal or heard of. I suppose this is true if you could consider all the chickens in the region of a whole. However, on the other hand, I know that you in South East Asia have accomplished much pioneering work on the control of Newcastle disease, especially in Malaysia. For the benefit of those of us in those parts of the world where less has been done to control Newcastle disease in village chickens, could you give us a summary of the principle conclusions from your experiences with this work?

With regard to Dr. Aini's comment on Newcastle disease, I would like to add my voice to those of both Dr. Saka Saheed Baba and Drs. Robyn Alders and Raul Fringe, who are all of the view that the control of Newcastle disease is a primary concern. Although it is quite possible to sample a given population at a given time and find that there is no evidence of the disease, I think that the evidence and reports that we have already do point unquestionably towards the control of Newcastle disease as a high priority. It is quite in keeping with the cyclical nature of the disease that there should be a given moment where there would be no serological trace of it, otherwise there would never be a susceptible population that could be attacked by it. The serological evidence should be taken together with what villagers report about the disease, and if we take this evidence together and add what we know from virological studies, I think we can say already that globally Newcastle disease is a very serious priority in village poultry. This is not to say that constraints such as predators and feed limitation are not also important.

Finally, I would like to comment on Mr. Eng-Leong Foo's question as to whether there is any group of diseases predominantly associated with commercial poultry. In fact, Dr. Aini has already mentioned that coccidiosis is a problem with commercial poultry, but not with village poultry. But I think that also we should not loose sight of the general association between intensification and disease. The more intensive the production the more there is a risk of the spread of infectious disease, and the more radical are the necessary medical and sanitary prophylactic measures. In intensive poultry production, at least for breeders and layers, which are kept for a reasonably long time, there is a long list of diseases against which it is necessary to vaccinate. Now for village poultry, it is not known whether the more secondary diseases are also present to the same degree, but simply masked by more lethal diseases, but it seems to me that it is possible that infectious agents such as reoviruses, for example, may be less prevalent in village poultry, where an unnatural degree of proximity does not pertain, than in the intensively kept poultry. The intensive poultry population itself may also provide the means for the selection of new pathological entities, which might not otherwise have arisen in the natural population. Take for example the new virulent form of Gumboro disease which originated in the European poultry industry, and which has now been spread around the world by this same industry, and which is, it seems, now infecting rural poultry. Would this have arisen without the ecological opportunity provided by the intensive poultry population?

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Prof. Dr. Aini Ideris
These are responses to all the comments regarding Lead paper 2:

1. Genetic changes/adaptations regarding disease resistance.
There has been no report of genetic changes or adaptations regarding disease resistance. As far as Malaysia is concerned, we found that village chickens are susceptible to all diseases reported for commercial chickens. Disease incidence however depends on the type of management.

2. Change of diet during sickness
When they are sick, the chickens either eat the food provided to them or they do not eat at all (Disney movie does not apply here!).

3. Disease in commercial chickens versus village chickens, as related to living conditions
As mentioned in my earlier answer (question 1), some diseases related to intensive management may not be common in chickens kept under free-range system. Coccidiosis for example is not common in village chickens kept under free-range. As soon as these chickens are kept in crowded confinement, coccidiosis is one of the diseases which needs to be controlled. Endoparasites are common in village chickens but not so in commercial chickens, mainly because of the scavenging nature of village chickens. So, management system, as rightly so mentioned by Dr. Jonathan G. Bell plays an important role in the prevalence of a disease in a flock of chickens, rather than the breed of chickens.

4. Mortality rate of a normal village chicken flock in Malaysia
As mentioned in my paper, there is limited data on the mortality rate for a normal flock. Losses start right from the brooding stage. Brooder losses are high, similarly with losses due to adverse conditions. In the absence of epidemic diseases, the mortality rate is around 20-30% (personal communication with farmers).

5. Control of Newcastle disease in Malaysia
As a result of the ACIAR project on HRV4 food-pellet Newcastle disease vaccine, the villagers are more aware of the control of ND, the need for vaccination as a prevention, and the availability of the vaccine. The HRV4 vaccine has since been commercialised, however, due to the logistical problems in transporting and storing large quantities of food-pellet vaccine, the vaccine manufacturer produces the vaccine in the freeze-dried form rather than coating it onto feed. The farmers either use the HRV4 vaccine (which is cheaper) or other imported vaccines (in areas where they are more easily available). There is less report of ND outbreaks in village chickens, now, as compared to about 6-7 years ago. However, whether this is due to HRV4 vaccine or not is difficult to say, since no study has been carried out to determine it. Nevertheless, the project definitely had its impact in making the villagers more aware of the need to vaccinate chickens against ND and many are vaccinating their chickens now.

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