Gross morphology of testes and gonadosomatic index of Khaki Campbell duck (Anas platyrhynchos domesticus) at different postnatal ages

Abstract

The present work is conducted to elucidate the gross morphology and gonadosomatic index (GSI) of testes of Khaki Campbell duck at different ages: at 1 day of age, at 1, 2, 3, 6 and 12 months of age. The testes of duck were found suspended from its abdominal surface to the roof of the abdominal cavity by mesorchiam. The testes were situated symmetrically on each side of the midline of the body and cranioventral to the kidney. The shape of the testes was elongated shaped and yellowish white in color at 1 day, 1 and 2 months old. At three months of age, the left testis assumed the shape of a bean, while the right testis remained elongated, and then at 6 months and 1 year old, both testes were bean shaped, white to creamy white in color. The paired testis weight was 0.004 ± 0.009g at day one old, which increased gradually as the age advanced and reached a maximum weight of 23.767± 0.804g at 6 months of age, then decreased at 1 year old. The mean length of the left testis and right testis was 0.37 ± 0.041 cm and 0.315 ± 0.040 cm respectively and mean width of the left testis and right testis was 0.17 ± 0.017 cm and 0.14 ± 0.032 cm respectively at day 1 old, which increased gradually as the age increased. The maximum gonadosomatic index 3.79 ± 0.401% which was recorded at the age of 6 months indicating high sperm production ability. Further in-depth study is necessary to clarify the reasons behind this.