Do heavy broiler chickens visit automatic weighing systems less than lighter birds?

1. In previous studies it was found that automatic broiler weighing systems can have accuracy problems. Researchers reported poor agreement between automatic and manual mean weighing used as a reference. The difference was observed especially after 4 to 5 weeks and this was explained by assuming that heavier birds visited the weighing system less at the end of the growing period. 2. Our study tested this hypothesis under practical production conditions. 3. In total, 193 536 digital images of broilers on and in the neighbourhood of the platforms were collected over three growing periods of 6 weeks. The area (upper view) of the broilers was calculated using image analysis techniques. 4. The hypothesis that the weighing system was used less frequently by heavier animals was confirmed. More specifically, statistical differences between the area of broilers on and in the neighbourhood of the weighing system could be demonstrated for week 5.

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