Effects of meloxicam administration on physiological and performance responses of transported feeder cattle

Abstract

This experiment evaluated the effects of meloxicam administration on physiological and performance responses of transported cattle during feedlot receiving. Eighty-four Angus x Hereford steers were ranked by BW on d -10 and assigned to 21 dry lot pens. From d -10 to 0, pens were fed alfalfa-grass hay ad libitum and 2.4 kg/steer daily (DM basis) of a corn-based concentrate. On d 0, pens were randomly assigned to 1) transport for 1,440 km in a livestock trailer and oral administration of meloxicam (1 mg/kg of BW) at loading (d 0), unloading (d 1), and daily from d 2 to 7 of feedlot receiving (MEL; n = 7); 2) the same transportation and treatment schedule of MEL but oral administration of lactose monohydrate (1 mg/kg of BW) instead of meloxicam (TRANS; n = 7); or 3) no transport and oral administration of lactose monohydrate (1 mg/kg of BW) concurrently with treatment administration to MEL and TRANS (CON; n = 7). Upon arrival (d 1), MEL and TRANS steers returned to their pens for a 21-d feedlot receiving with the same diet offered from d -10 to 0. Treatments were administered to steers via oral drench on d 0 and 1 or mixed daily with the concentrate from d 2 to 7. Full BW was recorded before (d -2, -1, and 0) treatment application and at the end of experiment (d 20, 21, and 22) for ADG calculation. Daily DMI was recorded from d 1 to 21. Blood samples were collected on d 0, 1, 3, 5, 7, 10, 14, and 21. During the initial 7 d of feedlot receiving, hay and total DMI were reduced (P <= 0.03) in TRANS vs. CON and MEL and similar between CON and MEL (P >= 0.26), whereas concentrate DMI did not differ (P = 0.16) among treatments. Mean ADG was reduced (P <= 0.03) in TRANS vs. MEL and CON but similar (P = 0.82) between MEL and CON. Moreover, TRANS had reduced G: F vs. CON (P = 0.01) and MEL (P = 0.05), whereas G:F was similar (P = 0.39) between CON and MEL. Serum NEFA concentrations were greater (P < 0.01) for TRANS and MEL vs. CON on d 1. Plasma haptoglobin concentrations were greater (P = 0.03) for TRANS vs. CON and MEL on d 5 and greater (P = 0.03) for CON vs. TRANS on d 10. Plasma ceruloplasmin concentrations were greater (P <= 0.04) for TRANS vs. CON on d 3, 5, 7, 10, and 14, greater (P = 0.03) for TRANS vs. MEL on d 5 and 7, and also greater (P = 0.05) for MEL vs. CON on d 3. In conclusion, meloxicam administration to feeder steers modulated the haptoglobin and ceruloplasmin responses and prevented the performance losses caused by long-distance transportation.