Effect of pasture vs. concentrate feeding with or without antioxidants on carcass characteristics, fatty acid composition, and quality of Uruguayan beef

A highly automated method and system for providing individual animal electronic identification, measurement and value based management of cattle in a large cattle feedlot. Through the use of (1) a computer system integrated with (2) automatic individual animal identification (3) multiple measurement and remeasurement systems with automatic data input and (4) a cattle handling and sorting system, animals are individually (a) identified and (b) measured by weight, external dimensions and characteristics of internal body tissue. With this information together with animal physiological characteristics and historical data, the computer system calculates the optimum (c) slaughter weight, (d) economic end point and (e) marketing date for shipment to a packing plant. After measurement, individual animals are (f) sorted by direction of the computer in response to calculations from the measurements. The computer system also calculates from individual animal data and other data (g) each animal's pro rata share of total feed intake for the animal's feed group. The computer system (h) stores individual animal measurement, performance and location data, which is used by management to (i) select animals for shipment from the feedlot for slaughter at the optimum time. Following an animal's shipment to a slaughter facility, its identification in the computer system is used to (j) correlate the live animal physical characteristics and performance data to the measured and evaluated carcass characteristics data obtained during the slaughter process and (k) build a data base to more accurately identify and measure value-based characteristics in subsequent animals produced and fed for more effective value-based selection and management of those animals.

Cattle management method and system

Fat-borne volatiles and sheepmeat odour.

Limousin-cross steers (n=135; 258+/-26 kg) were used to compare forage vs grain feeding on carcass composition and palatability attributes of beef when time on feed was controlled. Diets included a 95% alfalfa silage ration (AS) or a 68% high-moisture corn, 25% alfalfa silage ration (HMC). These were incorporated into six treatments to allow comparisons of end points based on similar days on feed or backfat finish. Dietary treatments included 1) HMC (4 mm), or cattle allowed ad libitum intake of HMC until slaughter at 4 mm ultrasound backfat; 2) AS (HMC-4), or cattle allowed ad libitum intake of AS until slaughter, regardless of finish, when HMC (4 mm) cattle were slaughtered; 3) AS (4 mm), or cattle allowed ad libitum intake of AS until slaughter at 4 mm backfat; 4) HMC (AS-4), or cattle allowed ad libitum intake of HMC until slaughter, regardless of finish, when AS (4 mm) cattle achieved 4 mm backfat; 5) HMC (RES), or cattle fed HMC at restricted intakes until slaughter at 4 mm backfat with feed offered at 75% of intake achieved by HMC (4 mm) and HMC (AS-4) cattle; and 6) AS (8 mm) or cattle allowed ad libitum intake of AS ration until slaughter at 8 mm backfat. Grain feeding generally increased (P .10) by diet with the exception of slightly less beef flavor and more off-flavor in forage-fed vs grain-fed beef. Higher (P < .01) concentrations of linolenic acid and lower (P < .10) concentrations of oleic acid in forage-fed beef may be partially responsible for diet differences in flavor.

Effects of forage vs grain feeding on carcass characteristics, fatty acid composition, and beef quality in Limousin-cross steers when time on feed is controlled.

Influence of feeding intensity, grazing and finishing feeding on meat and eating quality of young bulls and the relationship between muscle fibre characteristics, fibre fragmentation and meat tenderness

Palatability, Shelflife and Chemical Differences between Forage- and Grain-Finished Beef

One hundred seventy-three steer calves, selected at weaning to represent USDA classifications for frame size (Large, L; Medium, M; Small, S) and muscle thickness (No. 1, No. 2, No. 3), were assigned to three finishing diets (grain, 3.03 Mcal ME/kg DM; silage, 2.46 Mcal ME/kg DM; forage, 2.06 Mcal ME/kg DM), forming a 3  3  3 factorial with unequal subclass numbers. The steers were slaughtered at constant weights corresponding to their respective frame size classifications (L = 590 kg, M = 499 kg; S = 408 kg). Individual live weights were recorded every 28 d during finishing and, following slaughter, one side of each carcass was dissected into muscle, bone and fat. Diet interacted with frame size to affect growth rate. Frame-related differences in growth rate were very pronounced among grain-fed steers (L > M > S) but became smaller in magnitude as feeding intensity was reduced. Diet also had a significant effect on percentage separable carcass fat, despite the fact that the steers were slaughtered at a similar percentage (approximately 60%) of their estimated potential mature weights. Carcasses produced by grain-finished steers were fattest, and those produced by forage-finished cattle were leanest. The comparative fatness of steers finished on silage was dependent on frame size. Within the L class, carcasses produced by silagefinished steers were comparatively lean and were similar in fatness to carcasses produced by forage-finished cattle. Conversely, S steers finished on silage produced carcasses that were comparable in fatness to carcasses from grain-finished cattle. Frame-related differences in percentage carcass fat were significant only within the silage treatment group (S > L). Differences in carcass muscle-to-bone ratio were directionally consistent with visually discernible differences in feeder cattle muscling (No. 1 > No. 2 > No. 3)- The effects of muscle thickness on muscle-to-bone ratio were most pronounced within the L class. Diet was a significant source of variation in carcass muscle-to-bone ratio (grain > silage = forage) but did not alter the relationship between muscle thickness classification and muscle-to-bone ratio.

Influence of Diet on Growth Rate and Carcass Composition of Steers Differing in Frame Size and Muscle Thickness

Data from a serial slaughter of 324 steers were used to determine the effects of feeder-cattle frame size (Large, L; Medium, M; Small, S) and muscle thickness (No. 1, No. 2, No. 3) on absolute growth and carcass development. Yearling feeder steers representing nine frame-size • musclethickness subclasses were backgrounded 28 d; subsamples of steers (n = 6) from each subclass were slaughtered at 28~d intervals (O, 28, 56, 84, 112 or 140 d) during a 140-d finishing period. One side from each carcass was dissected into muscle, bone and fat. Absolute growth during finishing was linear. Allometric growth coefficients for muscle, bone and fat were similar for all nine subclasses. Frame size was related (P<.01) to differences in absolute growth rate (L>S), compositional maturity at a common carcass weight (S>M>L) and slaughter weight at a constant carcass-fat percentage (L>M>S). Muscle thickness did not influence absolute growth rate, but was associated with differences (P<.01) in carcass muscle-to-bone ratio at a common bone weight and in muscle percentage when carcass fatness was statistically standardized. The effects of muscle thickness on carcass composition were most pronounced within the large-framed group. Relationships of these results to the USDA feeder-carrie grading principles are discussed. (

Effects of Feeder-Cattle Frame Size and Muscle Thickness on Subsequent Growth and Carcass Development. II. Absolute Growth and Associated Changes in Carcass Composition

A multivariate analysis was performed to provide objective descriptions of visually perceived differences in feeder-cattle frame size and muscle thickness. Three hundred and twenty-four yearling feeder steers were selected to represent USDA classifications for frame size (Large, L; Medium, M; Small, S) and muscle thickness (No. 1, No. 2 and No. 3). The frame-size classification (F) of each steer was determined by a subjective evaluation of skeletal size-height and lengthin relation to maturity; the muscle-thickness classification (M) was based on a visual assessment of thickness of the rear quarter, forearm and gaskln-due to muscle expression and independent of differences in fatness-in relation to skeletal size. Six dimensional measurements (heart girth, hip width, stifle width, forearm circumference, body length and hip height) and a measurement of subcutaneous fat thickness (fat probe) were recorded for each steer to obtain objective assessments of traits that were emphasized during visual classification. A canonical varlate analysis was performed on the system of body measurements to quantify differences in feeder-cattle size and shape corresponding to USDA descriptions of frame size and muscle thickness. Over 95% of the dimensional variation among the nine F X M subclasses (L-No. 1, L-No. 2 . . . S-No. 3) was explained by the first two canonical vatiates. The first canonical variate (Zt) described morphological differences correspondingto variation in frame size and primarily reflected differences in absolute stature (L>M>S). Moreover, Z~ revealed a latent tendency for cattle of different frame sizes to vary in relative body dimensions (length, width and girth in relation to height). These relative dimensional differences were attributed to variation in developmental status. The second canonical variate (Z a ) primarily contrasted variation in rear-quarter thickness (relative to skeletal size) and shape corresponding to visually perceived differences in muscle thickness. Cattle perceived to be thickly muscled (No. I muscle thickness) had disproportionately wide and convexly shaped rear quarters, while steers classified as thinly muscled (No. 3 muscle thickness) were relatively narrow and flat through the rear quarters. Circumference of the forearm received secondary emphasis for discriminating among muscle-thickness groups. Evaluations of muscle thickness did not appear to be influenced by variation in subcutaneous fat thickness. Results of the analysis were used as an objective basis for interpreting the effects of feeder-cattle frame size and muscle thickness on subsequent growth and carcass development. (

Effects of Feeder-Cattle Frame Size and Muscle Thickness on Subsequent Growth and Carcass Development. I. An Objective Analysis of Frame Size and Muscle Thickness

R. A. Bowling

Papers

Palatability, Shelflife and Chemical Differences between Forage- and Grain-Finished Beef

Influence of Diet on Growth Rate and Carcass Composition of Steers Differing in Frame Size and Muscle Thickness

Effects of Feeder-Cattle Frame Size and Muscle Thickness on Subsequent Growth and Carcass Development. II. Absolute Growth and Associated Changes in Carcass Composition

Effects of Feeder-Cattle Frame Size and Muscle Thickness on Subsequent Growth and Carcass Development. I. An Objective Analysis of Frame Size and Muscle Thickness

Postmortem Muscle Alterations in Beef Carcass Temperature, pH and Palatability from Electrical Stimulation