LAUSR

The objective of the present study was to find the comparative efficacy of three extenders to preserve semen of Labrador-Retriever (LR) dogs at 5o C for a short term. The semen samples of LR dogs were collected by digital manipulation method and extended at the rate of 1:4 in Tris-Egg Yolk- Citric Acid-Glucose (TEYCAG), Tris-Egg Yolk- Citric Acid-Fructose (TEYCAF) and Egg Yolk-Citrate-Glycine-Glucose (EYCGG) extenders by split sample technique. Semen was evaluated at 0, 24, 48, 72, 96 and 120 hours of preservation. Mean motile, live and HOST-reacted sperm and acrosomal, head, mid piece and tail abnormalities of spermatozoa varied significantly (P<0.01) between extenders and between preservation periods. The interactions between extender and preservation period were also significant (P<0.01) except for HOST-reacted and head abnormalities of sperm. The highest mean motile, live and HOST-reacted sperm were recorded in TEYCAG extender which did not differ significantly from that of TEYCAF extender. Mean per cent sperm acrosomal and tail abnormalities were significantly (P<0.05) lower, and the incidences of mean sperm head and mid piece abnormalities were also lower in TEYCAG, but not significantly from that in TEYCAF irrespective of hour of preservation. Per cent motile, live and HOST-reacted sperm were significantly (P<0.05) lower and sperm acrosomal, head, mid piece and tail abnormalities were significantly (P<0.05) higher in EYCGG as compared to that in TEYCAG and TEYCAF irrespective of hour of preservation. It was concluded that the semen of LR dog sustained good quality during preservation up to 5 days at 5oC suitable for successful artificial insemination and would be preserved better in TEYCAG and TEYCAF extenders than in EYCGG extender, since more than 50 per cent sperm motility and live sperm were maintained up to 120 hours of preservation in the former two extenders.