323. A Preliminary Investigation of the Relationship Between Hoof, Liver, and Heart Abnormalities in Natural-program Bos Taurus Beef Cattle (<30 Mos) at Slaughter.

Abstract Our objective was to determine the relationship between hoof, liver, and heart abnormalities, and the relationship between those abnormalities and quality grade (QG), yield grade (YG), hot carcass weight (HCW), ribeye area (REA), and hide color in natural-program cattle at slaughter. Bos taurus beef cattle (N = 1,312), without dairy phenotype, were evaluated for each abnormality at a slaughter establishment in the Great Plains region of the United States (elevation:563m). Cattle were enrolled in a vegetarian-fed program that prohibited implants, diet-included hormones, and beta-adrenergic agonists. General linear mixed models were used to determine the prevalence of each abnormality within other abnormalities, hide color, YG, and QG. Student’s t-tests were used to determine differences between the severity of abnormalities for HCW and REA. Fifty-seven percent of cattle had hoof abnormalities, 33.61% had heart abnormalities, and 8.69% had liver abscesses. There was no evidence (P > 0.1630) to support a difference in the proportion of cattle with each hoof score within each congestive heart failure (CHF) or liver score. Liver abscesses were more prevalent (P = 0.0355) among cattle without heart abnormalities (CHF1) (94.37±1.19% (mean±SE)) than cattle with mild changes (CHF2) (88.6±1.42%). Gray, red, and tan-hided cattle displayed the lowest prevalence (P < 0.0134) of normal hooves (22.82±5.02%, 26.68±5.46%, 26.91±8.76%) relative to black/white (44.48±6.64%), red/white (55.04±9.01%), and tan/white (59.64±21.52%) hided cattle. Black-hided cattle had a lower prevalence (P < 0.0050) of normal hooves (38.37±5.10%) than gray or red and a greater prevalence (P = 0.0262) than red/white but were not different (P > 0.1853) from tan, tan/white, or black/white. Prime and Choice cattle had a greater prevalence (P = 0.0061) of corkscrew hooves (2.94±0.57%, 6.88±1.26%) than Select cattle (0.00±0.00%). There was no evidence (P > 0.2404) to support a difference in HCW or REA between liver scores. Cattle with CHF1 comprised 51.51±10.97% of the tan-hided animals and 44.10±9.35% of the red/white-hided animals. Cattle with CHF1 comprised less (P = 0.0041) of the black-hided animals (34.06±4.87%) than the tan/white (78.63±15.03%), red (46.70±7.01%), black/white (45.90±6.89%), and gray-hided (45.89±6.99%). Heart abnormalities were not present in YG1 cattle (0.00±0.49) and cattle with CHF1 were more prevalent (P = 0.0032) in YG2 (57.08±8.17) than YG4 (38.03±5.27), YG3 (37.62±5.22), or YG5 (27.08±5.41). Cattle with CHF3 (moderate changes) were heavier (P < 0.0001) (HCW=476.16±2.38 kg) than cattle with CHF1 (457.34±2.74kg) and CHF2 (460.76±2.38kg). HCW for cattle with CHF4 (severe changes) (469.54±9.82kg) was not different (P > 0.6291) from other CHF scores. Cattle with CHF2 had a smaller (P = 0.0125) REA (86.06±0.43cm2) than cattle with CHF1 (87.81±0.49 cm2) or CHF3 (87.71±0.46 cm2). Ribeye area for cattle with CHF4 was not different (P > 0.3966) (88.85±1.73 cm2) from other scores. These preliminary results suggest that relationships may exist between CHF and liver abscesses in natural-program cattle. Further relationships may exist between hoof abnormalities and CHF and hide color, YG, HCW, and REA in natural-fed cattle.