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Thomas J. Sexton

Publications and source records attributed to Thomas J. Sexton.

6 recordsLinked to original sources
USGS2005

Cryogenic preservation of semen from the Aleutian Canada goose (Branta canadensis leucopareia)

Aleutian Canada geese ( Branta canadensis leucopareia ) were inseminated with frozen-thawed semen containing 6% or 7% dimethylsulfoxide (DMSO) resulting in 32 fertile eggs and 17 goslings; with 7% DMSO, 19 of 31 eggs were fertile. Beltsville Poultry Semen Extender (BPSE), adjusted to 270 ± 30 mOs and 7.5 ± 0.4 pH, was used to dilute semen samples and the DMSO before cryopreservation. About half of the live spermatozoa in the fresh semen (92.9 ± 2.5% live cells, laboratory studies; 87.3 ± 7.3%, insemination trials) survived the freeze-thaw process (46.7 ± 7.8%, laboratory; 33.3 ± 17.8%, insemination trials). Samples of frozen-thawed semen contained a greater percentage of bent spermatozoa (27.1 ± 8.4% of live cells) than fresh semen (14.4 ± 3.0% of live cells). Fecal- and urate-contaminated semen (a common problem when collecting goose semen) reduced the sperm motility score from 3.2 ± 0.6 to 2.7 ± 0.7 and number of live spermatozoa in frozen-thawed semen from 49 ± 9% to 24 ± 18%. Other variables examined that had less of an effect on semen quality included semen extenders, semen holding temperature, dilution and equilibration, relationship between hour of semen collection and level of semen contamination, and the relationship between season and sperm concentration.

Zoo Biology↗
USGS1979

Artificial insemination of cranes with frozen semen

For the first time (1978) artificial insemination (AI) with frozen greater sandhill crane (Grus canadensis tabida) semen resulted in fertile eggs and chicks. During the 2 year (1977-78) study, 6 of 27 eggs produced were fertile. Three chicks hatched. Semen samples used for insemination were frozen and stored in liquid nitrogen for two months or less. Recent improvements in the laboratory indicated that a more effective sample can be prepared and greater fertility rates should be expected.

Book chapter↗
USGS1978

A comparative study on the cryogenic preservation of semen from the sandhill crane and the domestic fowl

SYNOPSIS: Recent findings on the cryogenic preservation of semen from the crane, Grus canadensis pratensis and the domestic fowl, Gallus domesticus, are compared. Highest levels of post-thaw motility for crane semen (55%) were obtained when semen was diluted 1:1 with the Beltsville Poultry Semen Extender (BPSE) and held for 30 min at 5 C before it was equilibrated with 4% dimethyl sulfoxide (DMSO) for 15 min. In contrast, post-thaw motility for fowl spermatozoa was highest (80%) when semen was diluted 1:3 with BPSE and held for 60 min at 5 C before it was equilibrated with 4% DMSO for 60 min. Post-thaw motility of spermatozoa of both species was highest when the following freezing rates were used: l C per min from +5 to -20 C, 50 C per min from -20 to -80 C, then plunging into liquid nitrogen which resulted in a rate of 160 C per min from -80 to -196 C. One of four crane eggs resulting from insemination with frozen-thawed semen was fertile, whereas 27 of 55 fowl eggs were fertile, but this difference may have been due largely to fewer spermatozoa being inseminated into the female crane than into the fowl.

Book chapter↗