|Loyd, Andrea - Texas Agrilife Research|
|Reuter, Ryan - Samuel Roberts Noble Foundation, Inc|
|Vann, Rhonda - Mississippi State University|
|Banta, Jason - Texas Agrilife Extension|
|Carroll, Jeffery - Jeff Carroll|
|Welsh Jr, Tom - Texas Agrilife Research|
|Randel, Ron - Texas Agrilife Research|
Submitted to: American Society of Animal Science Southern Section Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 11/4/2012
Publication Date: 6/25/2012
Citation: Loyd, A., Reuter, R., Vann, R., Banta, J., Carroll, J.A., Welsh Jr, T., Randel, R. 2012. Effects of long versus short duration transportation on body composition on Brahman x Hereford calves [abstract]. Journal of Animal Science. 90:13(Suppl. 2).
Technical Abstract: This study was designed to determine the effects of transport duration on body composition of Brahman x Hereford calves. Calves (8.5±0.4 mo of age) from Overton, TX, were blocked by sex (n=18 steers; n=14 heifers), BW, and temperament score and were randomly assigned to a transportation treatment of long (L; 25.5 h; n=16) or short duration (S; 5.5 h; n=16). L calves were abruptly weaned and transported for 12 h on a livestock trailer (300 kg/m2 stocking density). L calves were unloaded and rested for 6 h before being transported again for 13.5 h. S calves were abruptly weaned and transported for 5.5 h on another livestock trailer (300 kg/m2 stocking density). All calves were unloaded in Marietta, OK, at the same time. Calves received ad libitum access to water and a high roughage diet offered in GrowSafe® bunks for 98 d. Calves were weighed and sonogrammed immediately prior to transport, immediately after transport, and 28 and 98 d post-transport. Heifers had more (P<0.0001) rib fat (RIB; 0.53 vs. 0.34±0.06 cm) and rump fat (RUMP; 0.86 vs. 0.63±0.06 cm) than steers at all time points, and heifers tended (P<0.08) to gain RIB at a faster rate than steers. There was no effect (P>0.10) of transport duration on longissimus muscle area per kg BW (LMA/BW), % intramuscular fat (IMF), RIB or RUMP. However, transportation did induce changes (P<0.006) in body composition as LMA/BW increased (0.17 vs. 0.20±0.005 cm2/kg BW) and IMF decreased (2.87 vs. 2.54±0.16%) from pre- to post-transport. LMA/BW at 28 d post-transport (0.17±0.005 cm2/kg BW) was similar (P=0.60) to pre-transport; however, IMF was less (P<0.0001) at d 28 post-transport (2.42±0.16%) than pre-transport. Day 98 IMF (3.28±0.16%) exceeded (P<0.0001) pre-transport IMF. Results from this study suggest that calves may mobilize IMF for use as an energy source during transportation. Since IMF may be diminished for up to 28 d post-transport, this could ultimately impact the carcass quality of cattle transported to harvest.