Final Report for GS04-037
Forage finishing beef has emerged as a leading market niche for present day consumers and the process appeals to a number of specific consumer demands. Recent factors in the beef industry joined with traditional food safety concerns have prompted the typical beef consumer to examine a wide variety of aspects relating to the production and consumption of beef products. Results from our lab estimate approximately 30% of surveyed consumers in the southeastern U.S. (Alabama, Tennessee and Kentucky) are willing to pay a premium for forage finished beef (unpublished data, Auburn University). The southeastern U.S. has a natural opportunity to utilize high quality forages in unconventional finishing systems as an alternative method of finishing cattle. Numerous live and postmortem factors can affect the quality, color and dietetic quality of beef, and finishing diet composition is one of the most important live production factors. Animals finished on forages traditionally have been found to be inferior to concentrate finished counterparts when evaluating various live and postmortem measures of animal performance and product palatability. Tasco, a proprietary product derived from the dried brown seaweed Ascophyllum nodosum has been shown in various instances to increase marbling score and certain measures of retail display shelf life. Therefore, we proposed a study in which animals were finished on winter annual ryegrass with/or without supplementation/Tasco treatment to evaluate the effects on animal performance, carcass characteristics, palatability attributes and retail display shelf life appearance. In general treatment finishing diet had little significant effect on the evaluated factors. Utilization of winter annual ryegrass as a finishing diet, in the current study produced animals with average performance and carcass measurements when compared to industry standards. Regardless, of supplementation treatment beef was found to be average to slightly above average for all evaluated sensory, shear and retail shelf-life parameters assessed.
Most often cattle produced in the southeastern U.S. are destined for grain finishing facilities in the mid-western portion of the U.S. A majority of the cattle from the Southeast are finished, harvested, and marketed all in the Midwest which limits the marketing options of producers in the Southeast. Cattle from the Southeast are commonly marketed as feeder calves, which may actually change ownership several times before reaching their final destination to feedlots and feeding facilities in the Midwest. Continual transportation and environment changes can lead to animal health issues as well as decreased gain and feed efficiency. Some producer in the southeastern U.S. may choose to retain ownership of their cattle throughout the finishing phase in the Midwest. Nonetheless, increased transportation cost as well as increased rates of illness due to shipping may cause the producer to incur financial losses. However, the bulk of producers in the Southeast are compelled to market their cattle as feeder calves which limits their opportunity and role within the beef chain.
Much of the agricultural land utilized in the Southeast is highly suitable for production of quality forages. Furthermore, much of the agricultural land is in tillage or row crops and is under utilized in the winter months. A method of utilizing row crop lands during idle months as forage finishing systems may exist. These forage or grass systems may be utilized in finishing strategies as possible alternatives to traditional finishing on all concentrate diets. The opportunity to market cattle or beef from these systems may prove to open market segments and profits not currently recognized or available to producers in the Southeast.
The benefits of finishing beef cattle on forage have long been recognized as a cost effective alternative to finishing in confinement feeding facilities. The availability of feed grains for animal consumption in the Southeast is virtually non-existent; however, the opportunity to finish cattle on forage is a possibility. There has been an increased interest in establishing systems where animals are fed solely or partially on forage throughout growing and finishing. Some research has found forage with the addition of small amounts of concentrate the last 10-14 days before harvest to be an effective alternative to finishing cattle solely on a concentrate diet (Bidner et al., 1986). Furthermore, the addition of modest amounts of concentrate to a forage diet throughout the finishing period may also serve as a valuable finishing strategy (unpublished data, Auburn University). Forage finishing strategies could serve to open phases of the beef life cycle to producers in the Southeast that are not currently available.
Beef consumption has steadily risen to a plateau since its decline in the 1980’s and consumers have become more informed and demanding. The appearance of niche markets has become frequent and various consumer demands such as leaner beef are common (Mandell et al, 1997; Montgomery et al, 1982). Currently consumers are looking for a “natural”, healthier, and locally raised beef product. Grass or forage fed beef may have the opportunity to target those consumers within these identified markets.
The role forage finishing systems may play in the production of beef in the Southeast is of great importance to the sustainability and profitability of producers in the southeastern U.S. However, the effects of forage finishing on USDA quality grade and the time an animal must be on feed to achieve at least USDA Choice (Small marbling) could prove detrimental to forage finishing strategies. Data has shown that beef cattle fed all/or high-forage diets are less likely to grade USDA Choice and those that do grade USDA Choice require a longer finishing period when compared to cattle on all grain diets (McMillan et al, 1984). The economic importance of quality grade is well established. Research conducted by Savell et al. (1987) stated that packers, through signals they receive from purveyors and retailers, have demanded beef that grades at least USDA Choice; when it grades less, a substantial price discount usually has been paid. Most often carcasses from forage-fed cattle grade USDA Select (Slight Marbling) to USDA Standard (Traces marbling). Cattle finished on all/or high-forage diets have been found to achieve USDA Choice when finished for additional days when compared to cattle on all grain diets (Abdullah et al, 1979). Increased finishing times could increase inherent input cost as well as increase the grazing demand on available forage. Forage-fed carcasses discounted for undesirable quality grades coupled with increased days on feed could thwart some of the opportunities forage feeding systems would contribute to beef producers in the Southeast.
Additionally, the significance of quality grade and/or marbling as well as tenderness on overall beef palatability has been well documented by various researchers (Tatum et al, 1982; Kim & Lee, 2001; Platter et al, 2003). Platter et al. (2003) stated that consumer acceptance of steaks increases approximately 10% for each full marbling score increase between Slight to Slightly Abundant. In research conducted by Wheeler et al. (1999) USDA Choice steaks were found to be more tender than USDA Select steaks. Furthermore, Park et al. (2000) found that beef with high intramuscular fat have high juiciness, tenderness, and flavor scores when rated by consumers. A method to improve quality grade and decrease finishing times necessary to obtain at least USDA Choice would increase profitability and overall palatability of beef from forage finishing systems; thus, increasing the overall success, efficacy and sustainability of forage finishing systems in the Southeast.
Tasco-14® (Ascophyllum nodosum) supplementation.
Ascophyllun nodosum, is a brown seaweed that is primarily found in the coastal waters of the northern Atlantic Ocean. A dried meal of Acophyllum nodosum is obtained by solar drying the intact seaweed and grinding. Ascophyllum nodosum meal contains approximately 6.0% protein, 12.0% moisture, 22.0% ash, 52.0% carbohydrates and 6.0% crude fiber (Braden, 2003). Research conducted as early as 1950 as well as current data reported that animals fed seaweed have increased performance and immunity (Chapman, 1950; Saker, 2001). Allen et al. (2001) found that consuming Ascophyllun nodosum had effects on lipid metabolism by maintaining or increasing serum cholesterol levels in animals consuming treated endophyte infected fescue. Tasco, a proprietary extract (Acadian Seaplants Ltd., Dartmouth, Nova Scotia, Canada) from the brown seaweed Ascophyllum nodosum, has also been shown to increase marbling and USDA quality grade in cattle (Allen et al, 2001). Additionally, Tasco-14®, a proprietary brown seaweed meal (Acadian Seaplants Ltd., Dartmouth, Nova Scotia, Canada) has been found to increase marbling score and USDA quality grade in feedlot cattle when supplemented in two 14 day periods before slaughter (Braden et al., 2002). When Tasco-14® was supplemented researchers found that there were no biologically significant differences for all of the evaluated carcass yield characteristics with the exception of hot carcass weight. Researchers found that animals supplemented with Tasco-14® exhibited slightly smaller hot carcasses weights upon harvest when compared to the non-supplemented control animals when harvested at identical days on feed (Braden et al., 2002). It seems plausible that Tasco-14® supplementation may decrease the days of finishing necessary to obtain a minimum amount of marbling to grade at least USDA Choice. The supplementation of Ascophyllum nodosum in various proprietary forms has not been shown to negatively affect the sensory properties of meat from treated animals (Montgomery et al, 2001)
The current research is intended to evaluate the efficacy of Tasco-14® supplementation in various treatment diets as a method to increase the effectiveness and overall profitability of a forage finishing systems as alternative marketing option to beef producers in the southeastern U.S. The objectives are as follows:
1. Evaluate animal performance throughout finishing period as measured by average daily gain to determine efficacy of supplementation in forage diets
2. Determine the success of Tasco-14® supplementation to reduce days on feed necessary to obtain adequate endpoint fat thickness over the 12th rib and to successfully increase USDA quality grade as well as effects on evaluated carcass characteristics
3. Determine the effects of supplementation in various forage diets on steak palatability and muscle protein, fat and moisture.
Fall born steers crossbred steers (n=48) from the resident herd at an Alabama Agricultural Experiment Station where assigned to one of three breed type categories; primarily continental breeding, primarily Angus breeding, and primarily Bos indicus x Bos tarus breeding. Steers were also assigned frame scores based on hip height, age and weight. Steers with extreme frame scores (>6) where excluded from the study. Steers where assigned to pens with breed type and frame score equally represented in pen. Pens (n=12) were randomly assigned to one of four treatment diets consisting of; continual access to 1 hectare winter annual ryegrass (Lollium multifloram Lam.) with 0.0%, 0.0%+Tasco, 1.0%, and 1.0%+Tasco of the average pen bodyweight in supplemental soy hull pellets. All pens received ad. libitum loose mineral (Auburn University, Winter Grazing Mineral for Cattle, W.B. Fleming Company, Tifton, GA). Pens receiving Tasco treatment received Tasco at 15% of the mineral ration. Weights were recorded every 28 days and supplement levels were adjusted accordingly. Animal weight, 12/13th rib back-fat and longissimus muscle area were recorded every 28 days beginning on day 0 of the trial. Average daily gain was determined for a 175 day finishing period and for individual periods. Following a 48 hour chill USDA carcass characteristic were evaluated by trained Auburn University personnel. Upon fabrication striploins (IMPS#180) were collected from each left carcass side and vacuum packaged for further lab analysis. Wholesale cuts were cooler aged at 4°C for 21 days and proximate, shear force, sensory and retail display shelf life samples were serially fabricated from the anterior end. Steaks for sensory, shear and proximate analysis were vacuum-packaged and stored at -10°C until analysis. Retail display shelf life samples were placed on foam boats, over-wrapped with polyvinyl chloride film and subjected to 5 days of simulated retail display at 4°C. Trained sensory panel attributes were collected according to procedures from Cross et al. (1978). Warner-Bratzler peak shear force for each steak was obtained as prescribed by AMSA (American Meat Science Association, 1995) guidelines. Percent protein, fat, and moisture of each steak were recorded according to AOAC (Association of Analytical Communities) approved procedures. The retail shelf life of all steaks was determined by a six member panel trained according to AMSA (American Meat Science Association, 1980) guidelines.
In general finishing treatment regimen had little effect on the evaluated animal performance, beef palatability and retail shelf life factors. Average daily gain for the entire 175 day finishing period was not affected by finishing regimen. Average daily gain for the entire finishing period was 1.13, 1.14, 1.07 and 1.14 kg/day for 0.0%, 1.0%, 0.0%+Tasco and 1.0%+Tasco, respectively. No differences, due to finishing diet in average daily gain were seen for each of the 28 day periods. Recent work in our lab found little change in average daily gain of steers while on finishing diets of winter annual ryegrass with various levels of corn supplementation (unpublished data, Auburn University). The selected forage, winter annual ryegrass (Marshall) has been found to be on extremely high quality in relation to other comparable forages and this may account for similar gains between finishing regimen. Finishing regimen had no affect on evaluated carcass characteristics; lean maturity score, marbling score, preliminary yield grade, adjusted preliminary yield grade, hot carcass weight or longissimus muscle area. Marbling scores for treatment regimens were 355.41, 378.75, 353.33 and 394.86 (300=Select, 400=Choice) for 0.0%, 1.0%, 0.0%+Tasco and 1.0%+Tasco, respectively. Steers on 1.0%+Tasco had the highest numerical marbling score which may suggest a Tasco effect; however the relative differences between treatments were insignificant. Tasco supplementation and intake rates in the current study may have been a factor for lack of Tasco treatment response. Hot carcass weights ranged from 260.36 kg for 0.0%+Tasco to 279.86 kg for 1.0%. There were no differences in extractable moisture, fat or protein in relation to finishing diet. Furthermore, extractable fat was similar in rank to marbling score when evaluating the four finishing regimen. Striploin sample protein percentages for finishing diets were 24.21, 22.60, 22.50 and 22.52 for 0.0%, 1.0%, 0.0%+Tasco and 1.0%+Tasco, respectively. Finishing diet had little effect on the sensory and shear traits of the evaluated striploin steaks. All steaks were generally rated average to above average for all individual sensory traits; initial juiciness, sustained juiciness, initial tenderness sustained tenderness and flavor intensity. Initial and sustained tenderness tended to decline for treatments with increased forage composition in the diet. Sustained tenderness scores for treatments were 5.45, 6.16, 6.03 and 6.37 for 0.0%, 1.0%, 0.0%+Tasco and 1.0%+Tasco, respectively. Visual subjective color scores did not differ by finishing regimen for color, color uniformity, lean discoloration and lean browning. Shelf life color parameters declined with extended days of display, as expected. However, color parameter decline over days of display was independent of finishing regimen.
Educational & Outreach Activities
Informative sessions were conducted at an annul field day in which participants where advised on national animal identification principles, use of by-products in animal diets, grass-fed beef and forages in the system of forage finishing beef. Approximately 50 producer/families participated in this hands-on one day field session in which tours of livestock on forage finishing diets, animal identification and forage evaluation where highlights.
Areas needing additional study
In the current research we plan to analyze the effect of concentrate and Tasco supplementation on the animal anti-oxidant status, fatty acid profile and lipid stability. The effect of forage type on measures of animal performance, carcass traits and palatability attributes may be the leading research inquiry presently. Steers finished on certain forages have been found to possess a range of undesirable animal and product characteristics. The effect of various forage types must be evaluated in order to develop successful systems of finishing beef cattle on forages. Forage finishing strategies must produce beef that is relatively comparable to commodity beef in terms of economic, sensory and shelf life factors.