Research Article

Growth of selected bones and muscle groups in broiler chickens during rearing period

Barbara Biesiada-Drzazga, Teresa Bombik, Anna Rojek, Mariusz Kubiak, Maciej Penda, Urszula Brodzik

1. Acta Sci. Pol. Zootechnica, 11(1), 2012, 25‒34

Abstract. The aim of this study was to determine an increase in the length of skeletal bones and muscle groups in broiler pullets during the rearing period. The research material consisted of the Ross 308 broiler pullets. The analysis included keel bone, leg bones (tarsometatarsus, femur and tibia), wing bones (humerus and ulna) as well as breast, thigh, drumstick muscles and wing muscles located along humerus and ulna. Day-old chicks weighed 36.5 g on average and during the whole rearing period, i.e. until 6 weeks of age increased their body weight to 2229.2 g. From 1 to 42 days of age, the weight of wing muscles increased from 0.91 to 429.9 g, that of thigh muscles changed from 1.95 to 218.0 g and that of drumstick muscles increased from 1.27 to 140.7 g. At that time, the weight of wing muscles increased from 0.74 to 38.9 g. In day-old chicks, the lengths of tarsometatarsus, tibia, femur, ulna and humerus were 25.6 mm, 32.0 mm, 24.7 mm, 17.5 mm and 17.0 mm, respectively. The respective values for 6-week-old birds were 81.7 mm, 105.8 mm, 78.5 mm, 73.9 mm and 77.8 mm.Adifferent growth rate of the analysed traits as well as a clear decrease in this rate with increasing age of birds were found. For most analysed traits, the rate of increase in muscle weight was three times higher than that in the length of individual skeletal bones. At that time, the keel length increased from 20.4 to 132.6 mm. Positive significant and highly significant relationships were found between most analysed traits such as: body weight of chickens and the weight of their breast and leg muscles.

Keywords: age, bones, broiler pullets, muscles