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Angus×Hereford steers (n = 42) and heifers (n = 21) were ranked by gender and BW on d 0 of the experiment and randomly assigned to 1 of 3 treatments: 1) no transport and full access to feed and water (CON); 2) continuous road transport for 1,290 km (TRANS), or 3) road transport for 1,290 km, with rest stops every 430 km (STOP; total of 2 rest stops). Treatments were applied from d 0 to 1 of the experiment. Cattle from TRANS and STOP treatments were transported in separate commercial livestock trailers, within a single 2.1×7.2 m compartment, but through the exact same route. During each rest stop, STOP cattle were unloaded and offered mixed alfalfa-grass hay and water for ad libitum consumption for 2 h. Upon arrival of STOP and TRANS on d 1, cattle were ranked by sex and BW within each treatment and assigned to 21 feedlot pens (7 pens/treatment; 2 steers and 1 heifer/pen). Full BW was recorded before (d -1 and 0) treatment application and at the end of experiment (d 28 and 29). Total DMI was evaluated daily from d 1 to 28. Blood samples were collected on d 0 (before loading of TRANS and STOP cattle), 1 (immediately after unloading of TRANS and STOP cattle), 4, 7, 10, 14, 21, and 28. Body weight shrink from d 0 to d 1 was reduced (P<0.01) in CON compared to TRANS and STOP, and reduced in STOP compared to TRANS. Mean ADG was greater (P<0.05) in CON compared to TRANS and STOP, but similar (P=0.68) between TRANS and STOP. No treatment effects were detected (P≥0.18) on hay, concentrate, and total DMI. Mean G:F was greater (P=0.05) in CON compared to STOP, tended to be greater (P=0.08) in CON compared to TRANS, and similar (P=0.85) between TRANS and STOP. Plasma cortisol concentrations were greater (P≤0.04) in TRANS compared to CON and STOP on d 1, and greater (P=0.04) in TRANS compared to CON on d 4. Serum NEFA concentrations were greater (P<0.01) in TRANS compared to CON and STOP on d 1, and greater (P≤0.05) in TRANS compared to CON on d 4 and 7. Mean plasma ceruloplasmin concentrations were similar (P=0.19) among treatments. Plasma haptoglobin concentrations were greater (P≤0.04) in TRANS compared to CON and STOP on d 1, and in STOP compared to CON on d 1. In conclusion, inclusion of rest stops during a 1,290-km transport prevented the increase in circulating cortisol and alleviated the NEFA and haptoglobin response elicited by transport, but did not improve feedlot receiving performance of transported cattle.

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. [ABSTRACT FROM AUTHOR]

The objective was to evaluate the effects of flunixin meglumine administration on physiologi-cal and performance responses of transported cattle during feedlot receiving. Forty-five Angus x Hereford steers were ranked by BW on d 0 and assigned to 1 of 3 treatments: 1) transport for 1,280 1cm in a commercial livestock trailer and administration of flunixin meglumine (1.1 mg/kg BW; intravenous) at loading (d 0) and unload-ing (d 1 ; FM), 2) transport for 1,280 km in a commercial livestock trailer and administration of 0.9% saline (0.022 mL/kg BW; intravenous) at loading (d 0) and unloading (d 1 ; TRANS), or 3) no transport and administration of 0.9% saline (0.022 mL/kg BW; intravenous) concur-rently with loading (d 0) and unloading (d 1) of FM and TRANS cohorts (CON). Upon arrival and processing for treatment administration on d 1, steers within each treat-ment were ranked by BW and assigned to 15 feedlot pens (5 pens/treatment, 3 steers/pen). Full BW was recorded before (d -1 and 0) treatment application and at the end of experiment (d 28 and 29) for ADG calculation. Total DMI was evaluated daily from d 1 to 28. Blood samples were collected on d 0 (before treatment administration), 1 (after unloading but before treatment administration), 4,7, 10,14,21, and 28. Body weight shrink from d 0 to 1 was less (P < 0.01 ) in CON vs. FM and TRANS but simi-lar (P = 0.94) between TRANS and FM. Mean ADG was greater (P < 0.04) in CON vs. FM and TRANS but similar (P = 0.69) between TRANS and FM. No treatment effects were detected on DMI, but CON had greater G:F vs. TRANS (P = 0.08) and FM (P = 0.02), whereas G:F was similar (P = 0.68) between TRANS and FM. Mean plas-ma Cortisol concentrations tended (P < 0.09) to be greater in TRANS vs. FM and CON but was similar (P = 0.87) between CON and FM. Plasma NEFA concentrations were greater (P < 0.02) for TRANS and FM vs. CON on d 1 and greater (P < 0.04) for FM vs. TRANS and CON on d 4. Plasma ceruloplasmin concentrations were greater (P ≤ 0.03) for TRANS vs. CON on d 1, 4, and 7, greater (P ≤ 0.05) for TRANS vs. FM on d 4 and 7, and greater (P ≤ 0.04) for FM vs. CON on d 1 and 4. Plasma hapto-globin concentrations were greater (P ≤0.01) for TRANS vs. CON and FM on d 1 and 4 and greater (P ≤ 0.05) for FM vs. CON on d 1 and 4. In conclusion, flunixin meglumine reduced the Cortisol and acute-phase protein responses elicited by road transport but did not improve receiving performance of feeder cattle. [ABSTRACT FROM AUTHOR]

The objective was to compare the acute-phase response of steers receiving different doses of bovine corticotropin-releasing hormone (CRH). Fourteen weaned Angus steers (BW = 191 ±2.1 kg, age = 167 ± 4.7 d) fitted with an indwelling jugular catheter and a rectal temperature (RT) monitoring device were assigned to receive 1 of 3 treatments (intravenous infusion): 1) 0.1 &mgr;g of CRH/kg of BW (CRH1; n = 5), 2) 0.5 ug of CRH/kg of BW (CRH5; n = 5), and 3) 10 mL of saline (0.9%; n = 4). Blood samples were collected via catheters, relative to treatment infusion (0 h), hourly from -2 to 0 h and 4 to 8 h and every 30 min from 0 to 4 h. Rectal temperatures were recorded every 30 min from -2 to 8 h. Blood samples were also collected via jugular venipuncture and rectal temperatures assessed using a digital thermometer every 6 h from 12 to 72 h and every 24 h from 96 to 168 h. All plasma samples collected during the study were analyzed for concentrations of haptoglobin. All plasma samples collected from -2 to 8 h were analyzed for Cortisol concentrations. Serum samples collected hourly from -2 to 8 h were analyzed for concentrations of NEFA, IL-6, tumor necrosis factor (TNF)-&agr;, and interferon-&ggr;. Cortisol peaked at 0.5 h for CRH1 steers but returned to baseline concentrations at 1 h relative to infusion (time effect; P < 0.01). In CRH5 steers, Cortisol peaked at 0.5 h and returned to baseline concentrations 3.5 h relative to infusion (time effect; P < 0.01). Cortisol concentrations did not change after treatment infusion for saline steers (time effect; P = 0.42). In CRH1 steers, NEFA concentrations peaked 5 h after treatment infusion (time effect; P = 0.01). Conversely, serum NEFA concentrations did not change for CRH5 and saline steers after treatment infusion (time effect; P > 0.37). Mean serum TNF-&agr; concentrations in CRH1 steers after treatment infusion were greater compared with saline (P = 0.02), tended to be greater (P = 0.08) compared with CRH5, and were similar (P = 0.40) between CRH5 and saline steers. Mean RT in CRH1 steers after treatment infusion were greater (P < 0.04) compared with saline and CRH5 and similar (P = 0.50) between CRH5 and saline steers. Haptoglobin increased and peaked 72 h after treatment infusion for CRH1 steers (time effect; P = 0.01) but did not change for CRH5 and saline steers (time effect; P > 0.45). In conclusion, the bovine acute-phase response stimulated by CRH infusion is dependent on the CRH dose and the subsequent response in circulating Cortisol. [ABSTRACT FROM AUTHOR]