Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: March 7, 2012
Publication Date: June 25, 2012
Citation: Vann, R.C., Sanchez, N.C., Carroll, J.A., Chapman, J.D., Welsh Jr., T.H., Randel, R.D. 2012. Ultrasound body composition traits response to an endotoxin challenge in Brahman heifers supplemented with Omnigen-AF [abstract]. Journal of Animal Science. 90:319(E-Suppl. 3). Technical Abstract: This study examined the effect of feeding OmniGen-AF (OG; Prince Agri Products) on the body composition traits response of newly-weaned heifers to an endotoxin (lipopolysaccharide; LPS) challenge. Brahman heifers (n=24; 183 ± 5 kg) from the Texas AgriLife Research Center in Overton, TX, were separated into 2 treatment groups at weaning: 1) Control (C; n=12) and 2) OG (n=12; fed at 4 g per 45.4 kg BW) and fed for 69 d. On d 39, heifers were transported from Overton to New Deal, TX. On d 40, heifers were fitted with indwelling jugular catheters and moved into a barn with individual stalls. On d 41, heifers were challenged with LPS (0.25 ug/kg BW i.v.) and blood samples were collected at 0.5 h intervals from -2 to 8 h and again at 24 h relative to LPS challenge (0 h). Ultrasound body composition traits for longissimus muscle area, rib fat, percent intramuscular fat, and rump fat were collected at weaning (d 0), d 39, 44 and 69. Data were analyzed using the PROC Mixed procedure of SAS specific for repeated measures. Heifer BW increased throughout the study (P < 0.001) and was not affected by treatment (P > 0.68). Ultrasound body composition traits for longissimus muscle area, percent intramuscular fat, rib fat, and rump fat were all influenced (P < 0.0001) by day of the study. However, there were no effects (P > 0.20) of feeding treatment on ultrasound body composition traits throughout the study. There were tendencies (P < 0.09) for the OG group to have more stable rib fat and percent intramuscular fat measurements after transport and an endotoxin challenge. While no significant differences between treatments were observed in this study, the data suggest that OG supplementation prior to transport and LPS challenge may have preserved energy stores in Brahman heifers.