Tasco-Forage: IV. Influence of a seaweed extract applied to tall fescue pastures on sensory characteristics, shelf-life, and vitamin E status in feedlot-finished steers

Tasco-Forage is an Ascophyllum nodosum seaweed-based product that has incre ased antioxidant activity in both plants and animals. Endophyte (Neotyphodi um coenophialum ([Morgan-Jones and Gams] Glenn, Bacon, and Hanlin)-infected and uninfected tall fescue (Festuca arundinacea Schreb.) pastures in Virgi nia and Mississippi during 1997 were treated or not with 3.4 kg Tasco/ha in April and July. There were two replications of each treatment at each loca tion. Forty-eight steers (6/replication) grazed pastures at each location ( n = 96) from April to October prior to transportation to Texas Tech, Lubboc k, for finishing during a 160-d period in the feedlot. Blood (antemortem) a nd liver (postmortem) samples were collected. After slaughter and chilling, the left strip loins (IMPS #180) were collected from three randomly select ed steers from within each pasture replication (n = 48). Strip loins were v acuum-packaged and stored at 2 degreesC. At postmortem d 7, 14, 21, and 28, strip loins were removed from packaging and fabricated into 2.54-cm steaks . Following each fabrication day postmortem, the strip loins were repackage d and stored at 2 degreesC until the following postmortem time. After the p rescribed fabrication, steaks were overwrapped with polyvinyl chloride film , subjected to simulated retail display at 2 degreesC for up to 3 d, and su bjective and objective color were evaluated daily by a trained panel. Steak s from Mississippi steers that had grazed Tasco-treated fescue retained hig her (P < 0.05) CIE a* color scores throughout retail display. Steaks were m ore uniform and had less discoloration and less browning (P < 0.05) if they were from steers that had grazed Tasco-treated fescue, and the effect was greatest for steers from Mississippi (location x Tasco interaction; P < 0.0 5). The endophyte in tall fescue may decrease uniformity and increase lean discoloration and two-toning of beef steaks when removed from vacuum packag ing on or beyond d 21 postmortem (endophyte x Tasco x postmortem day intera ction: P < 0.05). Vitamin E in liver was increased (P < 0.06) and serum vit amin E was decreased (P < 0.09) in steers that had grazed the treated pastu res. These experiments indicated that Tasco applied to tall fescue during t he grazing season can improve color stability and extend beef shelf-life, p articularly in cattle grazing infected tall fescue. The mode of action of T asco is not clear, but antioxidants and specific vitamins may be involved.