Impact of Two-Stage Weaning on Calf Growth Parameters

Removal of the dam and change in the source of nutrition at weaning results in increased stress and frustration for calves. In an effort to minimize stress, two-stage weaning may be utilized. An anti-suckling device is placed in the calf’s nostrils 4 - 7 d prior to weaning based upon manufacturer recommended guidelines. Previous research involving the two-stage weaning method has shown calf weight loss prior to weaning. The objective of the study was to evaluate if the use of anti-suckling devices would impact calf growth when placed at 2 or 4 d prior to weaning. Data were collected over two years using registered Angus heifer and bull calves. Calves (n = 48 in yr 1 and n = 51 in yr 2) were utilized in a completely randomized design. Calves were stratified by weight and randomly assigned to 1 of 3 treatments; control (CON), 2 d with device prior to weaning (2D) or 4 d with device prior to weaning (4D). All calves were weaned using fence-line weaning on d 0. Calf growth performance were measured weekly from 7 d pre-weaning through 28 d post-weaning. For the 28 d post-weaning period, all calves were fed together in the same pen. Data were analyzed using the MIXED procedure of SAS with sex, treatment, and year as fixed effects. Corresponding interactions were also analyzed, but none were identified as significant. No differences (P > 0.37) were observed for any growth parameters based upon treatment. Sex significantly impacted (P < 0.01) calf weight, as bull calves were consistently heavier than heifers. Interestingly, no differences (P = 0.84) were observed between sexes in the pre-weaning period, however during post-weaning, bulls gained faster (P < 0.01) than heifers (1.26 kg/d vs. 1.00 kg/d, respectively). We also found that all calves in yr 2 grew at a significantly (P < 0.01) lower rate compared to yr 1 both pre- and post-weaning. Results from this trial indicate that bull calves gain weight at a faster rate following weaning compared to heifers. Further, application of the two-stage weaning method with device placement at either 2 or 4 d prior to weaning, does not impact calf growth rate.