PSII-12 Effect of aspirin to intentionally induce leaky gut on performance, blood markers of stress, and carcass characteristics of feedlot cattle

The negative impacts of stress on gastrointestinal (GIT) barrier function can result in compromised animal health. Aspirin (acetylsalicylic acid) is known to cause mucosal injury leading to increased gut permeability and tight junction damage. The objective of this study was to determine the long-term impact of leaky gut on animal physiology. In this experiment, 96 Simmental x Angus steers (355 ± 14.8 kg) were allotted by body weight and breed into two treatments: control (no aspirin) or aspirin fed at 50 mg/kg/d for 159 d. Steers were housed in 16 pens (8 pens/treatment) with 6 steers in each pen. Weight was recorded monthly and serum was collected on d 159 to be analyzed for lipopolysaccharide binding protein (LBP), interleukin-6 (IL-6), serum amyloid A (SAA), haptoglobin, and aspartate aminotransferase (AST). Data were analyzed using the MIXED procedure of SAS. Average daily gain (ADG) tended to decrease in cattle fed aspirin (P= 0.10). Aspirin decreased hot carcass weight (P= 0.05) and rib-eye area (P= 0.01)and increased fat thickness (P= 0.02), marbling score (P = 0.003), and yield grade (P = 0.01). Percent KPH tended to increase (P= 0.10) for steers fed aspirin. Aspirin had no effect on body weight, dry matter intake, gain:feed, days on feed, dressing percentage, liver abscess score, or percent liver abscesses. Aspirin tended to increase serum LBP (P= 0.07), but had no effect on serum concentrations of IL-6, haptoglobin, SAA, and AST (P≥ 0.30). This study indicates that leaky gut induced by long-term administration of aspirin has negative impacts on feedlot performance and carcass leanness. The negative impact of aspirin induced leaky gut on animal performance suggests that leaky gut caused by other factors (subacute acidosis, stress) may be a significant problem for the feedlot industry.