The study was conducted to assess the osteometric effects of surgical caponisation on long bones of cockerel chickens. Sixty- (60-) day-old chicks were distributed into two experimental groups with thirty (30) cockerels per group. The birds were caponised at eight (8) weeks of age. The mean of final body weights of caponized groups was significantly higher ( ) than the uncaponised group. The weights of all long bones measured as well as lengths between the two groups were not statistically different ( ) from one another except the weight of femur of the caponized group and the lengths of tibia and tarsometatarsus ( ) that differed significantly from one another ( ). All the proximal, midshaft, and distal diameters of all the long bones measured between the two groups were not statistically different ( ) from one another except the midshaft diameter of ulna that was significantly higher ( ) in caponized group. It was concluded that caponisation of cockerel chickens at eight (8) weeks of age has no significant osteometric effects ( ) on almost all the long bones studied when they were normalised to the final body weights. 1. Introduction Surgical caponisation is defined as a process whereby the testes are artificially removed via a surgical operation on 6- to 12-week-old chickens [1]. It results in androgen deficiency and thus secondary male sexual characteristics such as the comb, the wattle, fighting behavior, and vocalisation degeneration [2]. It is well known that the abdominal fat pad is significantly increased in capons, regardless of the breed and the age of caponisation or slaughter [3, 4]. There are conflicting reports on the effects of caponisation on the growth of chickens. Several studies have demonstrated that caponisation enhanced chicken growth [5–7] and has no effects on growth [2, 8, 9] or even negative results [10]. Androgen has long been recognized as playing an important role in bone development, physiology, and metabolism [11, 12]; increased growth rate is often achieved after caponisation and likely as a result of androgen deficiency [2]. In humans, Manolagas et al. [13] reported that depressed androgen through exposure to chemicals, testectomy operation, or age has adverse effects on bone growth and development. In poultry, however, very few experiments conducted on the effects of caponisation on the bones of chickens have shown consistent results. For example, Hutt [14] found increased bone length on the caponised white leghorn while Chen et al. [1] and Landauer [15] found no significant effects of caponisation on bone length of
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