Abstract
Abstract A flock of mainly Romney × Coopworth ewes was established to test sires for genetic differences in resistance to ryegrass staggers (RGS). This disease is a neurotoxic condition caused by ingestion of endophyte‐infected perennial ryegrass containing the mycotoxin, lolitrem B. Lambs, 18‐month males and females, and ewes of all ages were scored from January to March each year for RGS (0 or 1; 0 = no staggers), while grazing toxic pastures during natural outbreaks of RGS. Over 6 years (the autumns of 1988–93) and over all stock classes scored, age‐group means for RGS ranged from 0 to 0.16. A breeding value for RGS was calculated for each animal, incorporating data from all years and all age groups, provided that the mean year x age group score was at least 0.04. RGS data were also recorded on another Romney flock managed at the same site over the same time period. The heritability of RGS score over both flocks was 0.07 ± 0.02 and the repeatability over years was 0.24 ± 0.04. In March 1993, 170 ewes w...
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
