Influence of Unilateral Cryptorchidism on Libido, Haematology and Serum Reproductive Hormones, Total Protein, Lipid Profile and Oxidative Stress in West African Dwarf Goats

摘要

The failure of testicular descent (cryptorchidism) is known to cause abnormal testicular development and function. Unilateral cryptorchidism is prevalent in West African Dwarf (WAD) goats particularly in some areas where affected bucks are presumed to have better libido and reproductive efficiency by farmers. Androgens produced by the testes can influence libido and other hormonal and metabolic processes in the body. The study investigated the influence of natural unilateral cryptorchidism on serum reproductive hormones, total protein, lipid profile, oxidative stress, and haematology and libido in WAD bucks. Ten WAD bucks (aged 12 - 14 months) comprising 5 bucks with normal descended testes (N group) and 5 unilaterally-cryptorchid bucks (UC group) were studied. Blood and sera were collected and evaluated for haematology, serum total proteins and lipids (cholesterol, triglycerides and lipoproteins) concentrations, serum oxidative stress (catalase and lipid peroxidation activity), and serum levels of reproductive hormones (testosterone, FSH and LH). Libido testing of bucks was also performed by randomly isolating and confining each individual male with a doe on standing heat and recording the number of mountings made by the male within a period of 5 minutes as the libido score. The evaluated haematological indices and serum levels of proteins, lipids, oxidative stress indicators and reproductive hormones were not significantly different between the N and UC groups (p > 0.05). Although a higher mean libido score was recorded in N bucks compared to the UC group, this difference was not significant. Whereas no negative effects were observed in the evaluated physiologic indices in UC bucks, these findings do not support the presumption by farmers that UC bucks have better libido than bucks with fully descended testes. Therefore, these animals should not be selected for breeding to avoid increasing the prevalence of unilateral cryptorchidism due to its genetic attribute.