Skip to main content
ARS Home » Plains Area » Miles City, Montana » Livestock and Range Research Laboratory » Research » Publications at this Location » Publication #90663
Title: GENETIC CONSERVATION OF LINE 1 HEREFORD GERM PLASM

Author
item Macneil, Michael
item STAIGMILLER, ROBERT - RETIRED USDA-ARS

Submitted to: Governors Conference on the State of the Livestock Industry
Publication Type: Other
Publication Acceptance Date: 8/1/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: The Line 1 Hereford is a unique inbred genetic resource. Germ plasm from Line 1 has been used world-wide with large favorable impacts on the Hereford breed. Conservation of unique genetic resources is important to meet future needs of society. The National Research Council states that deciding whether or not to conserve germ plasm should not be based on current commercial value. In beef cattle, genetic conservation depends on breeding programs of adequate size or on freezing semen and embryos in sufficient quantities to regenerate a breeding population. The goal of his research was to identify procedures appropriate for conserving Line 1 Hereford germ plasm. Fifty-seven percent of bulls collected produced semen suitable for freezing. Only 16% of ejaculates collected were of good quality after freezing with post-thaw motility of 15-25%. Of 42 attempted flushes, 25 yielded quality 1 or 2 embryos suitable for trans- fer or freezing. One-hundred fifty six embryos and 80 unfertilized oocytes were collected. Thirty one percent of the embryos were quality 1 or 2. 53 transfers were made. These results raise concern for viability of cryogenic preservation of Line 1 Hereford germ plasm and may be further interpreted to suggest in situ conservation as a more preferable option.

Technical Abstract: The Line 1 Hereford is a unique inbred genetic resource. Germ plasm from Line 1 has been used world-wide with large favorable impacts on the Hereford breed. Conservation of unique genetic resources is important to meet future needs of society. The National Research Council states that deciding whether or not to conserve germ plasm should not be based on current commercial value. In beef cattle, genetic conservation depends on breeding programs of adequate size or on freezing semen and embryos in sufficient quantities to regenerate a breeding population. The goal of his research was to identify procedures appropriate for conserving Line 1 Hereford germ plasm. Fifty-seven percent of bulls collected produced semen suitable for freezing. Only 16% of ejaculates collected were of good quality after freezing with post-thaw motility of 15-25%. Of 42 attempted flushes, 25 yielded quality 1 or 2 embryos suitable for trans- fer or freezing. One-hundred fifty six embryos and 80 unfertilized oocytes were collected. Thirty one percent of the embryos were quality 1 or 2. 53 transfers were made. These results raise concern for viability of cryogenic preservation of Line 1 Hereford germ plasm and may be further interpreted to suggest in situ conservation as a more preferable option.