Ch 9 Live Cattle Evaluation, Grading, and Pricing

Transcription

1 Ch 9 Live Cattle Evaluation, Grading, and Pricing Dr. Fa-Jui Tan 1 U.S. Prime U.S. Choice U.S. Select U.S. Standard U.S. Commercial U.S. Utility U.S. Cutter U.S. Canner 2 1

2 Questions before class What is evaluation? Why evaluation? Based on what criteria? Who does the job? When does the job be done? How the job be conducted? 3 Purpose of live cattle evaluation Live market cattle evaluation an estimation of carcass characteristics vs. Specific characteristics evaluated An indication of amount of fat/muscle (cutability) quality grade carcass value live value Quality vs. Quantity Importance Species specific? Or applying to all species? 4 2

3 Weight The actual weight of the cattle at the time of evaluation or immediately prior to slaughter (why?) to determine cutability? and/or value to calculate yield grade? carcass weight hot carcass wt. (wt. of dressed carcass? just prior to chilling) chilled carcass wt. (wt. after carcass chilling) HCW=101.5% CCW 5 Uses of Live weight of cattle Characteristics Easy to obtain The most commonly used characteristic for determining value But, not a very precise estimate of cutability? Live cattle, carcasses, and beef cuts are bought and sold largely on a wt and grade Producers use wt to calculate production efficiency (i.e., weight per day of age) Wt is normally combined with several carcass characteristics to determine cutability and/or value. Live wt: actual wt vs. carcass wt: actual wt. or estimated wt.? 6 3

4 Live wt range Extreme range: 800~1700 lb (360~770kg) Normal range: 950~1500 lb (430~680kg) Average: 1150 lb (520kg)` HCW Yield grade (why?) % retail cuts Fatness (at the same wt): Heifer > steer > bullock 7 Dressing percentage Definition: (chilled carcass wt / live wt) 100 Extreme range: 45~68% Normal range: 55~67% Average: 62% DP varies with grade, type, degree of muscling, condition of the cattle being evaluated Extremely thin, dairy cow: < 45% Vs. Prime steer > 65% why? 8 4

5 Factors affecting the DP the amount of fill (stomach and intestine contents) degree of muscling wt of hide, head, feet degree of fatness (finish) grade Type Condition of the cattle being evaluated 9 Comparison btwn steer, heifer, bullock of the same live wt. Comparison DP of steer, heifer, bullock of the same live wt. P.88 Why? Comparison wt of steer, heifer, bullock of the same carcass fat amount P.88 Why? P

6 Table 9.1 Dressing percentage of cattle by quality grade Quality grade Average dressing % Prime 64 Choice 62 Select 60 Standard 57 Commercial 57 Utility 53 Cutter 49 Canner 45 Why? 11 Fat thickness Definition: Depth of fat in tenths of inches over the ribeye muscle at the 12th rib at a point 3/4 of the lateral length of the ribeye muscle from the split chine bone P.90 Figure 9.1 A, B, C 12 6

7 Measured location of fat thickness Fig 9.1 at a point 3/4 the lateral length of the ribeye muscle perpendicular to the outer surface of the fat Estimated approx in. ( cm) from the dorsal midline 13 Fat thickness Extreme range inch ( cm) Normal range steers and heifers ( inch cm) bullocks ( inch cm) Average 0.5 inch (1.3cm) Choice steers and heifers 0.35 inch (0.89cm) Choice bullocks 14 7

8 Fat thickness If too thick waste, retail yield If too thin excessive carcass shrink 0.08 inch (0.20cm)/100 lb carcass: most desirable 0.2 inch of fat at the 12th rib is necessary to protect the carcass against excess carcass shrink, discoloration during storage 12th rib fat thickness to calculate yield grade (p.89, p.123) YG = (2.5 adjusted fat thickness, 12 th rib) + ( hot carcass wt) + (0.2 % KPH) - (0.32 ribeye area) assessment of external fat on the carcass Fat thickness, retail yield Yield vs. Yield grade? 15 Ribeye area Area of the longissimus muscle measured in square inches at the 12th rib 1 inch cm 2 Extreme range in 2 (45cm 2 126cm 2 ) Normal range in 2 (65cm 2 116cm 2 ) Average 12.6 in 2 for 1150 lb steers Bullock, 1 in 2 steers, 1 in 2 > heifers (at the same wt) Estimation and adjustment of RA 1.1 inch 2 /100lb (live wt lb for steer), And then adjusted 16 8

9 Ribeye area widely used as an indicator of beef carcass muscling (Why?) easily measured largest muscle in carcass most valuable (why?) block beef (P. 119) to calculate yield grade To assess muscling REA vs. YG vs. % retail cuts? 17 Kidney, Pelvic and Heart Fat (KPH) Definition The internal carcass fat associated with the kidney, pelvic cavity, and heart expressed as a % of chilled carcass wt functions? KPH fat as of chilled carcass wt extreme range: normal range: Average: 3% 18 9

10 Average: 3% KPH For 1150 lb. live wt or 700 lb carcass with 0.5 in. fat (DP?) Heifer > steer > bullock (1%) P91 Small framed > intermediated framed > large framed (1%) Dairy type (1.5%) > beef type 19 KPH Purpose One of the factors to calculate yield grade YG = (2.5 adjusted fat thickness, 12 th rib) + ( hot carcass wt) + (0.2 % KPH) - (0.32 ribeye area) KPH fat yield grade retail cuts an assessment of internal fat in the carcass Boneless, closely trimmed retail cuts? P

11 P. 91 Table 9.2 KPH vs. estimated 12th rib fat thickness (inch) KPH What does this mean? 21 Marbling Definition: the intermingling of fat within the muscle (intramuscular fat). Normally evaluated in the ribeye muscle at the 12 th rib. Extreme range: devoid abundant Normal range: trace abundant Average: small modest 22 11

12 Marbling Used by the Federal Grading Service Average: small modest Small-Modest: Qualifies for the low to average Choice grade, P120 Modest marbling Typical of intermediate type and size steers ( lb) Marbling: Heifer > steer > bullock (at the same wt) P92 Estimated from the amount of external fat on live animal Fatter animal vs. leaner animals Fatter animal more marbling better quality Length of time on full feed low energy Young cattle not reached the fattening phase Marbling: the most important factor affecting quality grade. Fatness: an important factor in the estimation of both yield and quality grades. 23 Marbling 1 (Abundant) 2 Moderately Abundant) 3 Slightly Abundant 4 Moderate 5 Modest 6 Small) 7 Slight 8 Traces 9 Practically Devoid 10 Devoid 24 12

13 Maturity Definition: An estimation of the chronological age of the animal or carcass Assessing the physiological stages of maturity of bone and muscle characteristics To assess Degree of ossification of the thoracic cartilage (button) P92 The cartilage associated with the lumbar and sacral vertebrae Shape and color of the ribs Color of lean in the longissimus muscle at the 12th rib 25 Maturity Extreme range: A E Normal range: A E A maturity Most youthful 9-30 months P113 E maturity The oldest > 96 months P113 9(A) 30(B) 42C) 72(D) 96(E) Special requirements of maturity US Prime, Choice, Select, Standard grades must A or B maturity (P.120) C, D, E maturity only US Commercial, Utility, Cutter, Canner quality grades Bullock must be A maturity Intact male > 24 months bull not for quality grade Maturity: Heifer > steer > bullock P

14 Bullock must be A maturity intact male 24 m bull not eligible for quality grade At same wt or age heifer more mature than steer small framed, short bodied more mature than large framed, growthy cattle 27 Live Cattle Grading Beef Grading Quality grade (US Prime, Choice, Select ) Yield grade ( ) 28 14

15 Quality grade (QG) To evaluate degree of marbling Cannot be accurately determined on live cattle Live quality grade largely based on an evaluation of fatness Amount of finish is evaluated to predicted marbling degree of maturity Actual maturity seldom known Live quality grading fatness evaluation Carcass quality grading marbling, maturity 29 Quality grade (QG) determined on carcass live cattle QG evaluation on of fatness Finish to predict marbling Grade is estimated to the nearest 1/3 (US Prime +, US Prime 0, US Prime - ) 30 15

16 P 94 Figure Yield Grade (YG) P93 Yield of boneless, closely trimmed retail cuts from round, loin, rib and chuck Yield grade cutability Expressed as a percentage of carcass wt (i.e. 50 ) YG 1.0 cutability 54.6 YG 5.9 cutability

17 Factors to determined YG fat thickness at 12th rib ribeye area hot carcass wt KPH 33 Base Yield Grade YG 3.5 as the base YG YG lb carcass with 0.6 inch fat (12th rib) 11.0 inch 2 rib eye area 3.5 KPH P

18 Preliminary yield grade (PYG) PYG adjusted fat thickness Ribeye area Hot carcass wt 35 Fat thickness Table Adjusted fat thickness estimate (inch) PYG (base)

19 ribeye area 11.0 inch 2 + each 1 inch 2 YG 0.3YG 11.0 inch 2 each 1 inch 2 YG 0.3YG 37 Hot carcass wt 600lb each 25lb 0.1YG 600lb each 25lb YG Chilled carcass wt hot carcass wt 38 19