Evaluation of the follicular population and oocyte quality of zebu cows ( Bos indicus ) with anovulatory anestrus

Livestock plays a very important role in Cameroon agriculture, contributing about 9% (398.4 billion CFA) of the total agricultural production. In 2013, the national livestock population represented about 5.9 million cattle (Minepia, 2015). The productivity is very low because of many factors such as a poor genetic potential, diseases (pasteurellosis, foot-and-mouth, tick-borne and trypanosomosis), and reproduction in traditional systems with little or no livestock program (Ebangi et al., 2011). Reproductive technologies such as artificial insemination, embryo transfer and in vitro embryo production (IVP) were developed to minimize the effects of these factors and improve herd profitability (Morrell and Rodriguez-Martinez, 2010). IVP is widely used in the world and embryos can be produced from oocytes issued from ovaries collected at the slaughterhouse (Dauzet and Marquant-Le Guienne, 1994). The quality of these oocytes, IVP main limiting factor, is the result of multifactorial interactions involving the ovarian function, the surrounding cumulus complex, environmental factors such as heat stress, the genetic background, age and lactation status of donor animals (Boni, 2012). In a previous study, Kouamo et al. (2014) showed that zebu oocytes collected at a slaughterhouse have an average potential for IVP. In parallel, a high prevalence of genital tract abnormalities in donor cows (58.3%) has been reported. The predominant ovarian affection was anovulatory anestrus (Kouamo et al., 2016). To investigate further this common syndrome, the present study was carried out to evaluate the ovarian follicular population, oocyte recovery rate and oocyte quality of zebus with anovulatory anestrus.