Effects of N-Ethyl-N-Nitrosourea on semen quality traits of Nigerian local chicken

Abstract

To improve the Nigerian local chicken (NLC), N-Ethyl-N-Nitrosourea (ENU) can be used to introduce mutations into the genome to characterise the genetic architecture of complex traits and develop novel trait models and lineages. The extent ENU is tolerated as an effective mutagen in chickens and the knowledge of its biology of action is however required before its application. This is measured by the induction and duration of sterility in the absence of lethality in male mice. The objective of this study was to characterise the ENU effects on the onset and duration of induced sterility through direct studies of sperm (count and motility) from mutagenized cocks. In a randomized design experiment, 22 mutagenized and 20 non-mutagenized (control) NLC cocks were intraperitoneally injected with 300mg ENU/kg body weight fractionated as 3 doses of 100mg, and sham respectively and administered in 3 successive weeks. Semen volume (ml), sperm concentration (x10⁶/ml) and sperm motility were evaluated prior to ENU and Sham injected weekly up to week 13. Data were subjected to Mann-Whitney Wilcoxon at ᾳ_0.05. The ENU significantly (P < 0.05) reduced sperm concentration and motility but had no significant effect on semen volume at week 2. The duration of sterility could not be determined in this study as treated cocks did not show complete fertility recovery and ENU administered can be used for mutagenesis in chickens at the examined dose and regime.