Age related gross morphological studies on the thymus in postnatal Surti goat (Capra hircus)

The gross studies were conducted on the thymus of 18 postnatal Surti goats. Three distinct parts of thymus were recognized viz., unpaired thoracic part, caudally situated paired body (cervical part) and right and left cranial parts from day old kid to 9 months. The cranial parts were not observed from the age of 12 months onwards. The caudal cervical part of thymus was gradually replaced by adipose tissue between 14 to 48 months, however, traces of thymus embedded within the adipose tissue was observed in cranial mediastinum even at the age of 48 months. The right limb of cervical thymus was slightly longer than the left limb in postnatal Surti goats. The maximum mean weight (26.850 ± 2.885 g) and volume (22.333 ± 2.275 cc) of thymus was recorded between 4 to 9 months. Relative weight of thymus was 0.39% in neonatal kids, which was much higher as compared to 0.015 % in adult Surti goats. Negative correlation was observed between age and weight of thymus during 12 to 48 months.