Monday, November 13, 2006 - 2:45 PM

Effects of Different Pre- and Post-weaning Strategies on Grazing Behavior of Beef Calves.

Holly T. Boland1, Guillermo Scaglia1, William S. Swecker Jr.2, and Joseph P. Fontenot1. (1) Virginia Tech, 320 Litton Reaves Hall, Blacksburg, VA 24031-0306, (2) Virginia-Maryland Regional College of Veterinary Medicine, Large Animal Clinical Sciences, Blacksburg, VA 24061-0442

Management strategies were evaluated to reduce the level of stress caused by weaning. In October 2005, Angus cross-bred calves were allotted to three treatments 7 d before weaning: fence-line (FL) and nose clip (NC) as stress-reducing practices, or a control group (CTRL) using traditional abrupt separation on d 0. On d 0, all calves were separated from their dams, transported to another farm and held in a dry-lot overnight. Calves were kept within pre-weaning treatments and allotted to four post-weaning/backgrounding (d 1 to 42) forage treatments; Lakota prairie grass (L), Q4508-AR542 novel endophyte tall fescue (Q), Kentucky 31 endophyte-infected (E+) and endophyte-free (E-) tall fescues. Pedometers were placed on calves from d -6 to 0 and d 1 to 7. Direct visual observations of behavior were conducted in 10 min intervals from d -6 to -3 and d 1 to 4. FL calves took more (P<0.05) steps during the first 48 h after pre-weaning treatment initiation. After that, number of steps taken was similar between FL and CTRL. NC calves took the least (P<0.05) number of steps and spent less time eating. On d 1 post-weaning, CTRL calves took the most (P<0.05) steps. Time spent eating overall from d 1 to d 4 was greatest (P<0.05) for NC calves, intermediate for FL, and lowest for CTRL, however ADG for the entire 42 d backgrounding phase was highest (P< 0.05) for CTRL calves. There were no differences (P>0.05) in ADG between forage treatments. In this study, the use of FL or NC as stress-reducing practices did affect grazing behavior of calves with more time spent grazing and less time in unproductive activities, however CTRL had greater ADG overall. Backgrounding forage treatments did not affect overall ADG post-weaning although calves grazing E+ had numerically lower ADG.