An Improved Diluent for Long-Term Liquid Storage of Chicken Semen

A prototype chicken semen diluent formulation has been developed based on the results of preliminary experiments. Preliminary experiments indicated the substitution of glutamate for the acetate and phosphate generally present in chicken semen diluents improved post-insemination fertility levels obtained from chicken semen following 24-96 hours of in vitro storage. Additional preliminary experiments indicated potassium could be substituted for the sodium generally contained in chicken semen diluents without affecting post-insemination fertility levels. The dual biological buffers, BES and BIS-TRIS, that replace the single biological buffer sometimes contained in chicken semen diluents have opposing effects on the diluent’s pH and permit adjustment of the prototype diluent’s pH to a range of values without altering either its osmolarity or chemical composition. Semen collected from males of the Minnesota Dominant Marker Line was diluted 1:1 in the prototype diluent and stored in vitro for 96 hours at 4°C. Groups of twenty-four hens were inseminated with the stored semen samples. Osmolarities from 265-339 mOsm did not affect post-insemination fertility levels obtained from semen stored in the prototype diluent. The proportion of fertile eggs obtained post insemination from semen stored in the prototype diluent was significantly greater than that obtained from chicken semen stored in BPSE-l in the Chi-square test. Further investigations are necessary to determine the basis for the superiority of the newly-developed poultry semen diluent formulation to BPSE-I.