Pathomorphological Lesions in the Ovaries of Water Buffaloes
Authors: Yücel Tenekeci Gözde , Sepici Dinçel Aylin , Özkul İbrahim Ayhan 
Published: December 2024

Background: Buffalo breeding is common in many countries. Buffalo's milk is used in the production of mozzarella, yoghurt, ice cream, and various dairy desserts; meat is preferred in sausage production. The female buffaloes are bred to benefit from their milk and to obtain offspring. These animals, which are not suitable for feeding in barns, generally live in pastures, especially on wet land, and are very difficult to follow. Therefore, diseases occur randomly in slaughterhouses. Studies on genital system problems are very limited. Water buffaloes (Bubalus bubalis) are animals with economic value as many buffalo products are provided. In this respect, inspection and control of female genital disorders is fundamental to ensure good reproductive performance of female buffaloes. The aim of the study was to investigate pathomorphological lesions occurring in the ovaries of water buffaloes which were sent to slaughterhouses.
Materials, Methods & Results: A total of 198 ovaries of water buffaloes were collected from various slaughterhouses located in Adapazarı, İstanbul, Kocaeli, Samsun and Trabzon cities of Turkey. After macroscopic examination; tissue samples were fixed in 10 % buffered formalin, processed routinely and were stained with hematoxylin-eosin (HE). As a histochemical staining, Masson's trichrome staining was applied to characterize the lesions. Immunohistochemistry (IHC) was performed on 10 % neutral formalin fixed, paraffin-embedded, 4-6-μm-thick sections from ovaries using progesterone receptor (PR) with streptavidin-biotin complex peroxidase (StrepABC-P) method. Histopathologically, follicular cysts (n:147) and luteal cysts (n:22) were seen. While the cyst lumens were sometimes surrounded by granulosa and/or luteal cells, most of them were limited by the connective tissue capsule structure. This capsule structure was shown in blue by Masson's trichrome staining. Hemorrhage was observed in some cystic corpus luteum, diagnosed as corpus hemorrhagicum. In addition, cysts giving papillary extension into the lumen and inflammation of some ovaries were observed. Immunohistochemically, the staining with PR antibody in ovarian cysts showed no immunolabelling around the follicular cyst, while the nuclei of some of the luteal cells forming the luteal cyst had strongly nuclear positivity and slightly cytoplasmic positivity. In the biochemical examination of the fluids obtained from cystic ovaries (n: 37), the average of estradiol was 2.84 ng/mL (min: 0.01 ng/mL, max: 4.30 ng/mL) and progesterone average is 49.09 ng/mL (min: 1.88 ng/mL, max: 254.2 ng/mL).
Discussion: Ovarian cysts in buffaloes seem to be among the serious fertility problems as in cattle. Although the exact cause of ovarian cyts has not been determined yet, it is known that the hypothalamic-pituitary-gonadal (HPG) axis is disrupted in cyst formation in general. In this study, the mean estradiol value was within the standard range but close to the lower limit; progesterone value was above the limit. The increase in progesterone level was compatible with the pathogenesis of cyst genesis. Beside this result, staining with PR was positive in the luteal cells that formed the luteal cyst immunohistochemically. In addition, although the hemorrhages observed in the corpus luteum are considered physiological, it should not be forgotten that they can be vital if they rupture. All these results show us the animals sent for slaughtering mostly have serious genital problems threatening their fertility.
Keywords: buffalo, Bubalus bubalis, histopathology, immunohistochemistry, ovarian cysts, fertility.