Northern Pintail (Anas acuta) Science Article 1
Northern pintail duck semen and sperm traits were characterized, and the fertility of cold-stored spermatozoa was investigated using artificial insemination. Excellent qualityejaculates containing high proportions of motile spermatozoa were collected from drakes within 20 s by a massage technique. Semen was collected in Beltsville poultry semen extender, pooled and cold-stored (48C) for 0, 24, 48 or 72 h. Hens were inseminated with 100 ml twice a week, and eggs were assessed for fertilization and hatch success. Fertilization success was similar ( P> 0.05) for semen coldstored for 0 (51.6%), 24 (51.5%), 48 (41.1%) and 72 h (22.3%; P> 0.05). Similar ( P> 0.05) percentages of fertilized eggs hatched to live offspring (73.1, 71.4, 87.0 and 80.0%, respectively). Fresh semen was also equilibrated with 1 or 4% dimethylsulphoxide or glycerol, and cryopreserved at the following rates: (1) approximately 608C min-1 (in liquid nitrogen [LN2] vapour) for 10 min; (2) 18C min-1 to -208C, LN2 vapour for 10 min; and (3) 18C min-1 to -358C, all followed by immersion in LN2. After thawing for 30 s at 378C or 20 min at 48C, sperm motility and viability were assessed. The highest numbers of motile spermatozoa were recovered after slow-fast freezing (2) and thawing at 08C ( P< 0.05), but survival was inadequate to allow artificial insemination. Nonetheless, cold storage provides an effective means of short-term storage with no loss of fertility in this waterfowl species.
L. M. Penfold, V. Harnal, W. Lynch, D. Bird, S. R. Derrickson and D. E. Wildt, Reproduction(2001) 121, 267-275