Abstract
A heart scoring system has recently been introduced in the animal industry to provide a subjective measure on the degree of cardiac remodeling. Our aim was to objectify myocardial morphology in necropsied and production animals. A total of sixty-seven hearts from necropsied feedlot cattle and one-hundred and twenty-nine hearts from a regional (118 hearts) and local (11 hearts) abattoir. We conducted a preliminary study evaluating measurements including heart weight, ventricular free wall and septal thicknesses, and valvular circumference under differing storage protocols to ensure data accuracy on a larger scale. Health history was also obtained for the necropsied cattle. Necropsied and production animals had similar cardiac morphology, with harvested animals having on average a 5 mm thicker left ventricular wall than necropsied animals. Animals that made it to processing had an overall higher LV mid-wall average mean, 31.58 mm, than the feedlot, 27.68mm. There was also not an overt difference between ventricular thickness and heart scores in necropsied animals. It is also noteworthy that necropsied animals that were implanted, besides Synovex OneFeedlot had an overall lower heart score. Measurements showed there is 5mm difference in cardiac morphology and heart score between necropsied animals and harvest animals. The similar ventricular thickness could be due to an increase in ventricular chamber size rather than wall thickness. Our study is clinically relevant because it provides a better understanding how multifarious stressors related to finishing impact cardiac physiology. This could guide potential research for pharmacological treatment and potentially treat/prevent premature death and improve animal welfare.