65 Effect of post-weaning fecal egg count EBV on grazing ewe behavior after weaning

Abstract

Abstract Post weaning fecal egg count (PFEC) estimated breeding value (EBV) has been recently linked with improved immune competence and lamb survival to weaning, thus improving health though selection. Animal movement is also linked to animal health, however little is known about behavior differences in sheep with divergent PFEC EBV. Thirty Katahdin ewes were selected after weaning, from the Southwest Virginia Agricultural Research and Extension Center. Where high PFEC ewes (EBV > 172) and 15 low PFEC (EBV < -84) were selected. Upon placement into pastures, ewes were fitted with Digitanimal GPS collars that measure GPS location every 15 min and store data on a micro SD card. Additional data collection included bi-weekly body weights, FAMACHA scores, body condition scores and fecal egg count. There was no difference in any physiological measurement in these ewes for the duration of this 4-week study. However, significant differences were observed between groups for daily distance traveled. On average, High-PFEC ewes traveled 4.52 km, where low ewes traveled only 4.16 km (P < 0.0001). The average distance traveled between GPS signals (every 15 min) was 48.6 m for high ewes and 47.0 m for Low-PFEC ewes (P < 0.0001). Interestingly, the time of day where maximum activity occurred (1506 h vs 1448 h; High and Low-PFEC respectively) was not different, nor was the distance those ewes traveled in that hour (522.6 vs 519.2 m). These data provide a preliminary snapshot of movement differences that occur between PFEC groups and may inform future studies to evaluate linkage between health and movement in grazing livestock.