Artificial insemination in Houbara bustards (Chlamydotis undulata): influence of the number of spermatozoa and insemination frequency on fertility and ability to hatch.

Between 1989 and 1992, artificial insemination was used in the reproduction of two subspecies of Houbara bustard (Chlamydotis undulata macqueenii and Chlamydotis undulata undulata) at the National Wildlife Research Center, Taif. The laying period was between January and July and the mean annual egg production in C. undulata macqueenii was 10.2 and in C. undulata undulata was 7.6. No differences were found in sperm production between the two subspecies: the mean volume of ejaculate was 0.08 ml; the mean sperm concentration was 350 x 10(6) spermatozoa ml-1; and the mean number of spermatozoa per ejaculate was about 20 x 10(6). Large intra- and inter-individual variation was found in sperm parameters. Intra-individual variation in number of spermatozoa per ejaculate was due mainly to seasonal variation. The mean quantity of spermatozoa produced per week by fully sexually mature Houbara bustards was 165 x 10(6). There was no significant difference in fertility or in ability to hatch between the two subspecies. Overall, in 1992, mean fertility was 69.3% and 49.2% of eggs hatched. Females showed a median sperm storage duration of 10 days and a maximum sperm storage duration of 22 days. A positive correlation was found between fertility and quantity of spermatozoa inseminated (R = 0.99, P < 0.001). Sperm storage duration was related to the number of spermatozoa inseminated. The best results (85% fertile eggs) were obtained when more than 10(6) spermatozoa were inseminated between 3 and 6 days before laying. Analysis of hatching showed that embryo mortality increased when inseminations were performed more than 10 days before laying.