Follicular Population and Oocyte Yield Associated with Reproductive Pathologies in Cows (West Region – Cameroon)

Abstract

This study aimed to evaluate the relationship between the follicular population, oocyte yield, and reproductive pathologies in cows. It was conducted in slaughterhouses in Cameroon’s west region as well as at the University of Dschang’s animal physiology and health research unit. Post-mortem examinations were performed on 132 local Zebu cows (Gudali, White, and Red Fulani) from which ovaries were collected. 2965 follicles were analyzed and classified based on their size (small, medium, and large). The results showed an average of 22.47 ± 5.38 follicles per cow. The numbers of small, medium, and large follicles were 11.62 ± 2.63, 7.89 ± 2.18, and 1.53 ± 1.51, respectively. From oocytes harvested (graded I to IV), an average of 11.48 ± 2.11 oocytes per cow was observed. The average numbers of grade I, II, III, and IV oocytes were 4.35 ± 1.92, 3.59 ± 2.06, 3.59 ± 1.85, and 3.62 ± 1.75, respectively. 65.9% of the cows assessed had at least one reproductive pathology, including endometritis (18.2%), metritis (11.4%), and anestrus (27.3%). Furthermore, breed, age, and body condition score (BCS) also negatively influenced these reproductive pathologies. Older cows (≥7 years) and those with excellent BCS (BCS = 4–5) exhibited better reproductive performance (P < 0.001). However, pathologies had no significant effect on follicles and oocytes harvested. In conclusion, breed, age, and body condition score (BCS) considerably influence the follicular and oocyte production of local cows. Red Fulani cows had the highest oocyte yield, while White Fulani had a good oocyte index.