The effect of a commercial feed additive on the immune-metabolic axis, liver function and predicted carcass quality in purebred Angus steers

摘要: Abstract To determine the effect of commercial feed additive OmniGen-AF® on immune, physiological, and carcass ultrasound variables in steers during backgrounding, transition, finishing phases, nine purebred Angus half-sibling were randomly assigned to one two treatment groups: Control (n = 4) OmniGen-AF (OG; n = 5). Cattle offered 0 (Control) or 56 g daily OG throughout a 28-d backgrounding period (limit-fed predominantly forage diet), 14-d transition period, 56-d high concentrate diet (104 days total). During three feeding periods, whole blood serum was collected evaluate markers immune function physiology, respectively. Across basal supplementation increased chloride (P = 0.02) haptoglobin (P = 0.03) concentrations decreased NEFA (P = 0.001) concentrations. At end high-concentrate vs. attenuated decrease paraoxonase increase AST concentrations, marker liver cell necrosis. Carcass prediction measurements, 30-day intervals phase, indicated lower predicted numerical yield grades due higher REA (P = 0.009) tendency for less 12th rib fat (P = 0.06) steers. Weight gain, intake, efficiency, quality did not differ between treatments. In conclusion, may act immune-metabolic axis across studied phases support healthier livers improved by decreasing deposition increasing REA.