Forage-Based Beef Finishing Systems: A Review

Abstract

The objective of this paper is to review alternative methods of increasing the use of forage in beef finishing systems. Most finishing systems based on an all‐forage diet have not been particularly successful. Without grain finishing, the final product can have an inconsistent quality grade and a grassy flavor. The greatest sensory difference between forage‐fed and grain‐fed steers appears to be the flavor of the fat. Diterpenoids seem to be the off‐flavor's source. These are derived from the action of ruminal microorganisms as they break down chlorophyll. Phyt‐2‐ene has been identified as the most discriminating compound for off‐flavor. It was also found to be the strongest indicator that a steer had been forage‐finished. As time on grain lengthened, the levels of ‐ tetradecalactone and ‐hexadecalactone increased, indicating their correlation with desirable flavor characteristics of grain‐finished beef. Other investigators have correlated the off‐flavor to C 18:3 unsaturated fatty acids. The two methods that show the most promise and increase the use of forage in beef finishing systems are (i) supplemental feeding of cattle on pastures to reduce length of time required for feedlot finishing and (ii) finishing cattle in a pasture with supplemented energy. Efforts to reduce feedlot time have lessened the total concentrate fed and have been economically successful. When finishing cattle in a pasture with supplemental energy, those studies that limited grain intake the last 60 to 80 d before slaughter had mixed results. However, when proper forage management was used in order to ensure adequate supply of high quality forage, carcasses with acceptable quality were produced. Researchers who provided limited supplementation or energy for at least 112 d and fed free choice grain the last 60 to 80 d before slaughter reported that USDA Choice beef was produced. However, USDA quality grade is not necessarily an adequate means to determine the effectiveness of a pasture‐based finishing system. Researchers have to determine when meat flavor changes from “grass” to “grain” and the possibility of achieving this transfer on pasture with energy supplementation. Research Question Cattle are typically finished in a confinement feedlot. Lately, these feedlots have come under close scrutiny. Two of the major concerns are: (i) animal waste with its potential impact on water quality and (ii) economic implications of feeding large amounts of grain to fatten cattle. To respond to these concerns, there is a growing interest in using more pasture in the finishing phase of cattle production. Three of the major reasons for this interest are: (i) an increasing pressure to use practices that are environmentally friendly, (ii) a search for alternative methods of finishing that are profitable, and (iii) a desire to reduce the amount of grain fed to livestock. The beef industry needs to seriously consider all alternative production systems for finishing beef. This study reviews methods of increasing the use of forage when finishing beef, while m...

Effect of low- and high-forage diets on meat quality and fatty acid composition of Alentejana and Barrosã beef breeds

“…Melton (1983) discussed the possibility that an increased intensity of undesirable flavours could be associated with the thermal oxidation of PUFA. Forage-fed beef can experience decreased flavour acceptance due to volatiles from fat oxidation and chlorophyll derivatives (Griebenow et al, 1997). This was not observed in AL and BA breeds.…”

Comparison of organoleptic quality and composition of beef from suckler bulls from different production systems

“…Beef from grass based systems is often characterized as having less intense flavour, and is less preferred by consumers (Griebenow et al, 1997). Differences in flavour of beef from concentrate and grass based systems can be attributed to variation in fatty acid profile and other constituents in the beef (Baublits et al, 2006).…”

Producing tender and flavoursome beef with enhanced nutritional characteristics

“…Grass has higher PUFA, and particularly higher n-3 PUFA, primarily as linolenic acid, than grain-based ruminant feeds. In general, grass-fed beef has higher concentrations of PUFA, particularly in the phospholipid fraction, than grain-fed beef (Griebenow et al 1997). As shown in Table 4, an increase in the proportion of grass in the diet of finishing steers decreased the SFA concentration, increased PUFA:SFA, increased the n-3 PUFA concentration and decreased n-6:n-3 PUFA (French et al 2000c).…”

“…Grain source had little effect (Miller et al 1996), while source of ensiled forage generally also had little or no effect on beef flavour (Berry et al 1988;Moloney et al 1999). In many American studies panellists rated the flavour of grass-fed beef inferior to that of grain-fed beef (Griebenow et al 1997). Since flavour desirability and flavour intensity increase with fat content (Owens & Gardner, 1999), these findings may reflect differences in fatness in animals produced on both rations.…”