A comparative study on the follicular dynamics between sexually receptive and non-receptive algerian female rabbits after mating

This histological study compared ovarian follicular growth in local Algerian breed of female rabbits between mating and the moment of the potential ovulation, in two groups of animals: 32 receptive does were mated with a buck and 25 non receptive does in which mating was assisted by manual restraint of the female. In each group, 2 to 6 rabbits were slaughtered at various stages (0, 1-2, 3-4, 5-6, 7-8, 9, 10 and 11-12 hours post coïtum (p.c)) and for each of these stages respectively 2, 4, 4, 4, 4, 4, 4, and 6 receptive rabbits and 2, 4, 4, 3, 4, 2, 2 and 4 non-receptive rabbits. In receptive rabbits, the precursor signs of the ovulation appear from the fourth hour p.c: capillary lumina dilation, a slight oedema appear ed in the theca interna region which becomes prominent two hours later. At eight hours p.c the ovum and its immediately surrounding cells were practically floating free in the folliculi liquor. In addition to the oedema in the theca interna layer, an oedema just below the surface epithelium often appeared. Before rupture, the oedema in the apex had almost disappeared and the follicle wall was very thin in this region. An ovulation is observed at 10 hours p.c. Between ten and twelve hours p.c, only four on the six studied receptive does have ovulated and showed onl y one ruptured follicles. At different stages, the non-receptive ovarian female rabbits presented many atretic and healthy follicles. The oedema in the theca interna appeared in only one rabbit from 6 hours p.c. For a majority of preovulatory follicles, ovum lost their spherical shape and presented signs of degeneration. On non-receptive does, no ovulation was observed till 12 hours p.c.These results illustrate the difficulty of a non-receptive does to ovulate and suggest for receptive does, an ovulation asynchrony and an interval between mating and ovulation often greater than 12 hours. Further longer studies will be necessary to precisely describe the follicular grow th on receptive and non-receptive rabbit does of the Algerian local population.