Morphological changes of oviduct in postnatal development and in oestrous cycle of heifers

Abstract

The aim of the work is to describe microscopic and sub-microscopic changes of oviduct of 40 heifers of Pinzgau breed in post-natal development (3^rd, 6^th and 9^th month of age) at subclinical experimental hypoglycaemia (the value of glucose in blood plasma was 1.9-2.2 mmol) and in oestrous cycle. The oviduct samples for histological study were gained by vivisection from three parts of oviduct. Samples were fixed for LM in formaldehyde and for SEM and TEM in glutaraldehyde paraformaldehyde. Subsequently they were processed by usual method which is use in laboratory for Lm and electronmicroscopical studies. We discovered progressive changes in the length of oviduct in post-natal period (+7.9cm up to 9^th month) and in comparison with sexually mature animals retarded growth at hypoglycaemic 15 months old heifer (18.0±1.8cm). The length of oviduct in cycling heifer varied depending on the stage of cycle (21.7±1.9 in diestrus or 24.8±2.5 in oestrus). At the same time we have discovered progressive changes in relative volume of epithelium during development depending on the part of oviduct and age. This volume was on the level of 3^rd – 6^th month of age at hypoglycaemic animals. The most significant changes were observed in ampulla and infundibulum during the development as well as during oestrous cycle. The same tendencies were observed as representation and character of epithelium cells. There were no ascertained significant changes between ciliary and secretory cells, with the exception of hypoglycaemic heifers. This cannot be assumed about these cells during oestrous cycle. In their representation there were hormonal changes regulating individual stages of cycle. The sub-microscopic changes of cells in post-natal development as well as in oestrous cycle were also described. The energy deficit appeared in retardation of growth and development changes at animals with subclinical form of hypoglycaemia