Count your chickens before they hatch: low cost solutions

credit:Nick Sparks

For small-scale farmers and the rural poor in India, backyard poultry is an important livelihood activity providing valuable potential for improving income and nutrition. However, many backyard small-scale producers face production problems and there has been relatively little research on local technologies suited to small-scale poultry keeping. In the semi-arid districts of Udaipur and Tamil Nadu, between 20 and 30 per cent of eggs fail to hatch during the winter period. During the summer, when temperatures often exceed 40 degrees Celsius, hatching rates are even lower. However, the development and introduction of simple technologies to improve storage and to monitor eggs during the crucial stages of embryonic development, have yielded some interesting results.

Most small-scale poultry farmers do not have the appropriate means or knowledge to monitor embryonic development. Generally all eggs are incubated, with farmers assuming that the majority of eggs will hatch. But during excessive summer temperatures, there are a number of factors that may contribute to hatching failure: eggs may not be fertilised, the embryo may have died during embryonic development or the egg may be contaminated with bacteria. None of these conditions are detectable just by looking at the egg so they are all left for the full incubation period, which means that eggs that don't hatch are wasted, instead of eaten or sold.

Throwing light on the problem

credit:Nick Sparks

Candling, the shining of a bright light through the egg shell, is a simple method which allows the stage of embryonic development to be estimated. The only essential equipment required is a good light source, such as a good quality torch, and a darkened area in which the eggs can be assessed. Eggs that will not produce a viable embryo can be removed early, roughly four to seven days into the incubation period, and then consumed or sold. Candling is widely used in the poultry industry, but the concept was new to the villagers in Udaipur and Tamil Nadu. The key to encouraging farmers to adopt this method was to develop a cheap battery-operated candling technology, made from a torch and metal box, which proved simple to make with local materials. Villagers soon recognised the value of candling, and it was widely promoted by the project.

Turning down the heat

Temperatures above 27 degrees Celsius are well known to increase embryo mortality rates. The research team* led by Nick Sparks and Czech Conroy, concluded it was possible that the high summer temperatures during March to June were causing an increased number of eggs to fail to hatch. Another simple technology based on locally available materials was developed to reduce and stabilise the temperature of the eggs. With the help of two groups of poultry keepers, trials were carried out in 2003 and 2004, comparing a treatment using a storage technology that kept the eggs cool with a control group kept under normal storage conditions. All of the eggs were candled first, to confirm that they were fertile.

Evaporative cooling was the technique tested to reduce the temperature of eggs. A half-moon shaped bowl was filled with an earth and sand mixture and kept moist with water. A piece of jute bag was then placed on the sand to prevent the eggs coming into direct contact with water. The eggs were placed on the bag with a cotton cloth or woven basket placed over them. Finally, until the hen had stopped laying, the bowl was placed either on a shelf or ledge or on the floor inside the family building. Once the hen was ready to incubate the eggs, all the eggs were placed under her again, as is traditional practice. The results significantly improved the number of eggs hatched, achieving between 80 to 90 per cent hatching rates using the evaporative cooling technique compared with just under 70 per cent for eggs stored using the traditional method.

Increasing outreach and awareness

The techniques for reducing egg loss have been disseminated to several hundred villages and awareness of the importance of small-scale poultry raised amongst senior government policy-makers and politicians in Rajasthan and Tamil Nadu. As candling of eggs is relevant in any poultry-keeping system in any country, the technologies have potential application beyond India, and the egg cooling technology is also relevant in any region where temperatures may exceed 30 degrees Celsius. The technologies may need to be adapted for particular systems but their advantages lie in that they make use of local equipment, they are low cost, easy to use, and result in a marked improvement in the number of eggs which will hatch, and reduced wastage of those which will not.

Article written by: Czech Conroy, Natural Resources Institute, University of Greenwich, UK; Nick Sparks, Avian Research Centre, Scottish Agricultural College, UK;and Dinesh Shindey and L.R. Singh, BAIF Development Research Foundation, Pune, India