ISSN: 1659-2751



Analysis of the Adaptability and Productivity of Two Genetic Lines of Laying Hens (Sex Link and Isa Brown) under Free-range Conditions in the Humid Tropics


In this study the adaptability and productivity of two genetic lines of laying hens were analyzed. There was no difference in the number and weight of eggs/day/week laid for the two breeds. The percentage of eggs laid/week was significantly different (p≤0,05). Mortality was 6,67 % in both groups of birds. It was also found that the Isa Brown chickens had a better conversion rate. With regards to the Haugh grade and the thickness of the shell no statistically significant difference was found between the eggs of the breeds studied. The color of the yolk and the cholesterol levels in the eggs was found to be significantly different (p≤0,05) in favor of the Isa Brown eggs when compared with the eggs of the Sex Link. The final conclusion was that the Isa Brown hens adapt better to free range conditions and have a better conversion index than the Sex Link chickens.

Key words: Adaptability, movable hen house, day and line, hens, eggs, Effective Microorganisms (EM), free range, productivity, system.

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