Weight Variation in Broiler Chickens at Marketing: Causes and Treatment

Dr. Hashem Gamash, Chief Agricultural Engineer, Consultants

The weight variation in broiler chickens at marketing is one of the most prominent problems facing broiler projects. It is a frequently discussed topic among poultry farmers and a major problem for many project owners. Although the mortality rate is sometimes low, weight differences can reach more than (400) grams per bird.

For example, if the average overall weight at marketing is around 2 kg, we may find some birds weighing 2.4 kg, others not exceeding 1.6 kg, while the rest fall somewhere between these two limits. This variation is not simply a defect in the appearance of production; it is an indicator of administrative, nutritional, or health problems that directly impact the quality of the final product and the profitability of the project. Dealing with it requires careful management, starting from hatching through the marketing stage. Reasons for variations in broiler weights:

1. Genetic variations within the flock. Even in flocks with a homogeneous genetic makeup, there are natural differences in growth rates and response to feed, leading to weight variations.
2. Uneven food distribution. This is related to the insufficient number of feeders or drinkers, or their poor distribution within the barn. Feeders must be at an appropriate height (at the bird’s shoulder level) to facilitate access. Poor organization leads to stronger birds dominating resources, while weaker birds are neglected.
3. Uneven lighting. Variations in light intensity within the barn lead to variations in consumption activity and growth. It is important to use a uniform lighting system and monitor light and temperature distribution using well-distributed thermometers within the barn.
4. High population density (crowding). Overcrowding increases competition for food and water and negatively impacts uniform growth. It is recommended to adhere to the appropriate density.
5. Health and immune differences. Some birds may be infected with subclinical diseases such as coccidiosis or respiratory infections. These diseases affect nutrient absorption and feed conversion efficiency. Therefore, comprehensive periodic tests, conducted by reliable laboratories, must be conducted to monitor the health and immune status of the flock.

6- Uneven temperatures within the barn; the presence of cooler or hotter areas affects the distribution of birds and, consequently, their consumption and growth. It is recommended to use thermometers distributed in different areas, especially in barns that exceed 85 meters in length. It is also preferable to use internal air chute to reduce temperature differences.

Finally, achieving uniform weight in broiler chickens requires integrated management, encompassing genetic, nutritional, environmental, and health aspects. Each stage of rearing contributes to reducing differences and improving overall flock performance, thereby enhancing product quality and increasing profitability.