Submitted to: Journal of Animal Science
Publication Type: Abstract only
Publication Acceptance Date: 4/11/2006
Publication Date: 7/9/2006
Citation: Eicher, S.D., Johnson, T.A., Marchant Forde, J.N. 2006. Age at transport effects on behavioral responses in dairy calves to novel stimuli. Journal of Animal Science. 84(1):305. Interpretive Summary:
Technical Abstract: This study evaluated the effects of age at transport on behavioral responses to novel stimuli within a test environment. Eighteen Holstein calves were randomly assigned to treatments according to age at day of transport; 2 to 3-d-old (young,Y), 4 to 5- d-old (moderate, M), or 6 to 8-d-old (old, O). Each calf was transported for 6 h (d 0). Then calves were placed in outdoor hutches until d 39 when they were moved to the USDA-ARS Livestock Behavior Research Unit for behavioral testing on d 43 (6 wk after transport). A 21.3 m corridor was designed with several novel objects spaced approximately 2.4 m apart; including an entry, red bucket in the first corner, black mat, translucent plastic curtain, horizontal striped plank, darkened space, silver gates, reflecting metal, and open red gate to finish. Force was measured by 1=yelling; 2=moving into flight path; 3=pats; or 4=pushing to pass the obstacle. Calves went through the corridor once on d 43, then 3 times on d 44, 45, and 46. Data for the first experience with the corridor were reported previously, in which the Y calves tended to take longer to cross the first corner with a bucket than O calves and less force was needed to pass the second corner, for Y compared to M calves. All time data were log transformed and statically analyzed using Mixed procedures and force data were analyzed using the Exact test in the Frequency procedures of SAS. Run time decreased with replication for the curtain, grate, dark and reflective metal (P<0.05). The silver gate and reflective metal were passed more quickly by the M than the Y or O calves (P<0.05). Force required to enter the corridor on the 1st day was greatest for the Y calves on replicates 1 and 2 (P=0.01). Only on the 3rd run on d 46 did the Y calves require more force to pass the curtain than the M calves (P<0.05). On d 45 run 3, the O calves required more force (P=0.04) to pass the final gate than the M calves. Overall, the M calves passed many obstacles more quickly and required less force, while the older calves required more force after the 6th replication.