مقاله دعوت شده: ملاحظات تغذیه و مدیریت برای گاوهای گوشتی دارای التهاب ناشی از استرس 1

Beef cattle are exposed to several stressors when relocated from cow-calf ranches to feedlots, including transport and feedlot entry. These events elicit a myriad of stressors that increase (P < 0.05) plasma concentrations of proinflammatory cytokines and acute-phase proteins (APP), and the magnitude of the APP response during feedlot receiving was negatively correlated (r = −0.50, P < 0.01) with ADG and DMI. Hence, strategies to decrease the stress-induced APP response during feedlot receiving were investigated. In Exp. 1, steers were assigned to continuous road transport for 1,290 km, or road transport for 1,290 km with rest stops every 430 km. Inclusion of rest stops decreased (P ≤ 0.04) plasma APP concentrations on d 1 of feedlot receiving but did not increase receiving (P > 0.68) ADG and G:F. In Exp. 2, steers received or not Ca-soaps of soybean oil during a 28-d preconditioning and then were transported for 24 h. Supplemented steers had less (P < 0.01) plasma concentrations of tumor necrosis factor-α and greater (P = 0.02) ADG during feedlot receiving. In Exp. 3 and 4, respectively, steers were transported and administered flunixin meglumine at truck loading and unloading (1,280-km transport) or meloxicam at loading and during the initial 7 d of receiving (1,440-km transport). Both treatments decreased (P < 0.05) the APP response during feedlot receiving, but only meloxicam increased (P < 0.04) receiving ADG and G:F. Therefore, inclusion of rest stops during transport, supplementing essential fatty acids during preconditioning, and administering nonsteroidal anti-inflammatory drugs are methods to decrease the stress-induced APP response during feedlot receiving, whereas essential fatty acids and meloxicam enhanced receiving performance.