Effect of Two-Stage Weaning Duration on Behavior in Beef Calves.

In beef cattle, weaning is a stressful time for both the dam and calf. Calves experience physical separation from their dam, and typically experience a change in diet. One recent method developed to counteract the stress of weaning, is the two-stage weaning process. This procedure incorporates a nose flap which prevents suckling. Based on the recommendation from the manufacturer, it should be used for 4 – 7 d prior to separation from the dam. Previous research has shown that cattle weaned in this manner exhibit fewer stress-related behaviors. The objective of this study was to evaluate if nose flap placement 2 or 4 d prior to weaning would affect the behavior of beef calves. Data were collected over 2 consecutive years utilizing 48 registered Angus bull and heifer calves (256 ± 6 kg) in a completely randomized design. Calves were stratified by BW and randomly assigned to 1 of 3 treatments; control (CON), 2 d with nose flap prior to weaning (2D) or 4 d with nose flap prior to weaning (4D). All calves were subsequently weaned via fence-line weaning on d 0. Behavior observations were collected for 6 d pre- and post-weaning in 2 h blocks starting at 0730, 1200 (yr 1 only), and 1700 h. Activities observed were classified as eating (EA), suckling/attempting (SU), walking (WA), or inactive (IA) which included lying, standing, and ruminating. Individual observations were compiled into a percentage of the day spent doing each activity and these were analyzed using the MIXED procedure of SAS. Analysis of EA resulted in a day×treatment interaction (P < 0.01), whereby prior to weaning, CON calves generally spent less time eating than either 2D or 4D but more time eating than 2D calves post-weaning. For IA, no interaction (P > 0.27) was present, however there was a significant day effect (P <0.01). Results for SU showed a day×treatment interaction (P < 0.01), as calves suckled/attempted to suckle less following application of treatment than CON calves. Similar to other activities, WA showed a day×treatment interaction (P = 0.02) in which CON calves spend a greater amount of time walking after weaning compared to 2D and 4D calves while spending less time walking pre-weaning. Results from the current study suggest that utilization of the two-stage weaning method may impact stress-associated behaviors often observed prior to and immediately following weaning.