The Effect of Semen Storage Temperature and Diluent Type on the Sperm Quality Index of Broiler Breeder Semen 1,2

Abstract: The sperm quality index (SQI) is predictive of fresh semen quality. Our objective was to examine if semen storage affects the SQI obtained from undiluted semen, or semen diluted with either Beltsville Poultry Semen Extender (BPSE) or Minimum Essential Medium (MEM) and held for 8 h at 4, 21, or 41 C. Deado sperm percentage was higher and SQI was lower from undiluted versus diluted semen. Dead sperm percentage was higher and SQI was lower for semen stored at 41 C than at lower temperatures. Overall,o there was a linear increase in dead sperm percentage and linear decrease in SQI over storage length. Regardless of diluent, there was a linear increase in dead sperm percentage over time for semen stored at 4 and 21 C. For semen held at 41 C and diluted with BPSE or MEM there were respective quartic ando o linear increases in dead sperm percentage over time; a drastic linear increase existed for undiluted semen. There was a linear decrease in SQI from undiluted semen and semen diluted with MEM over time at 4 C;o however, for semen diluted with BPSE, there was a linear increase. The SQI from undiluted semen stored at 41 C decreased linearly over time. At 41 C, a cubic relationship existed for SQI over time for semen dilutedo o with BPSE, and a linear decline was detected for semen diluted with MEM. In conclusion, the SQI is indicative of changes induced by diluent type, storage temperature, and length of semen storage. Key words: Sperm quality index, dead sperm, beltsville poultry semen extender, minimum essential mediu