1Faculty of Veterinary Sciences & Animal Husbandry, S.K University of Agricultural Sciences & Technology-Jammu, RS. Pura, Jammu-181102 (J&K), India
Department of Veterinary Anatomy & Histology, College of Veterinary Sdence, Assam Agricultural University, Khanapara, Guwahati-781 022, India
*Part of PhD Thesis of the first author submitted to Assam Agricultural University, Khanapara, Guwahati-781 022
This study was conducted on the thyroid gland of thirty six male Assam goats divided into six age groups viz. group-I (0-day), group-II (2 months), group-III (4 months), group-IV (6 months), group V (8 months) and group-VI (10 months) consisting of 3 animals in each group. Tissue pieces from the thyroid lobes and isthmus were fixed in 10 per cent Neutral Buffered Formalin solution and subsequently processed for paraffin sections and stained with Mercuric Bromophenol Blue method for Protein, McManus method for glycogen, Aldan Blue method at pH 1.0 for acid mucopolysaccaharides and Fuelgen reaction for nucleic acids. The reaction for basic proteins was weak in the capsule of thyroid glands from birth to 4 months of age (group-I to III) and weak to moderate in the older goats. Within the follicles, the principal cells exhibited weak to moderate reaction in day-old kids (group-I), moderate to strong in 4 and 6 months old goats (groups-III & IV) and moderate reaction in the succeeding age groups. The Para follicular cells revealed weak to moderate reactions for basic proteins in day-old kids (group-I), moderately reactive in 2 month old kids (group-II) and exhibited a strong reaction in 4 and 6 months old bucks. The connective tissue ofthe capsule and inter follicular stroma of the thyroid glands were PAS positive. The basement membrane of the follicle showed moderate PAS reactions. The follicular and Para follicular cells exhibited weak to moderate PAS reactions. Fine glycogen granules could be seen at the apical border of the follicular cells in 4 and 6 months old goats (groups-III & IV). The tissue of the thyroid gland showed very faint reaction to acid mucopolysaccharides in all the age groups except in 2 month old kids (group-II), in which the inter follicular tissue revealed weak reaction. The connective tissue of the capsule, septae and the inter follicular stroma revealed very weak Fuelgen reaction in all the age groups. The Follicular and Para follicular cells of the thyroid follicles showed mild to moderate Fuelgen reaction in the kids of 4 months of age.
Assam goat, Histochemistry, Postnatal ages, Thyroid gland
