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Degree

Master of Science, Ohio State University, Animal Sciences, 2010.

Abstract

Jersey cattle are recognized as being slower growing and having more yellow fat compared with other breeds, thus limiting the use of this breed for beef production. Because Jerseys are slower growing, they require additional time on feed to achieve acceptable market weights and yield acceptable hot carcass weights. Although Jerseys face challenges, the resulting product has other quality aspects that exceed the general beef population. Gaps in knowledge exist regarding the optimum forage level in finishing diets on growth performance, carcass characteristics, and beef palatability. The objective of this study was to evaluate the effects of forage level (12 vs. 24% sudangrass:alfalfa hay, DM-basis) in steam-flaked, corn-based finishing diets on carcass characteristics, palatability, and retail color stability of Jersey beef. Seventy-nine Jersey steers were blocked by weight and randomly assigned one of the following treatments for a 385-d trial period: Jersey low- 12% (JL; n = 38) or Jersey high- 24% (JH; n = 39) forage, DM-basis. Forty-eight hours postmortem (PM), strip loins were removed, vacuum-packaged, and aged at 3°C for 18 d PM. Following the aging period, steaks from the longissimus muscle were sliced, vacuum-packaged, and frozen (-20°C) until analyzed. Steers fed the low forage diet had greater (P < 0.05) backfat and tended to have greater dressing percent compared to steers fed the high forage diet. Live weight, HCW, LMA, and USDA Yield Grade were not affected (P > 0.05) by forage level. Steers fed the low forage diet on average tended to bring a 6% greater value ($63.73 more per head) compared to steers fed the high forage diet. Objective color (L*, a*, b*) measurements decreased (P < 0.05) over time of display across treatments. There were no differences among treatments for L*; however, overall during retail display JH had greater (P < 0.05) a* and b* values than JL. Subjective color scores increased over time of display and were not affected by forage level. Warner-Bratzler shear force (WBSF) values and cooking loss were not affected by forage level. All measured sensory panel ratings were more favorable for JL steaks than JH steaks. These results suggest that forage level had minimal effects on carcass characteristics, color stability, and beef palatability; however, feeding a low forage diet decreases input cost and results in a greater value carcass. Finishing fed Jersey steers in conventional feeding systems can be accomplished meeting beef industry expectations and result in a high quality beef product.

Subject Headings

Livestock

Keywords

beef; forage; Jersey; sensory

Committee / Advisors

Paul Kuber
Francis Fluharty (Committee Member)
Steve Loerch (Committee Member)
Henry Zerby (Committee Member)

Document number: osu1275493720
Permalink: http://rave.ohiolink.edu/etdc/view?acc_num=osu1275493720

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