2019 Commercial Steer Study Guide

Transcription

1 2019 Commercial Steer Study Guide Phone:

2 Table of Contents Health... Pg. 1 Proper Usage of Drugs and Chemicals in Food Animals...Pg. 2 Cattle Vaccines...Pg. 4 Immunizing Beef Calves...Pg. 6 Basics of Cattle Immunity...Pg. 10 Recognizing and Managing Common Health Problems in Beef Cattle...Pg. 12 Biosecurity for Beef Cattle Operations...Pg. 20 Foot Rot in Beef Cattle...Pg. 24 Bloat Prevention and Treatment in Cattle...Pg. 25 Clostridial Diseases...Pg. 29 Quality and Yield Grading... Pg. 32 Beef Quality Grading...Pg. 33 Beef Yield Grades...Pg. 37 Basic Management and Information... Pg. 42 Beef Performance Glossary...Pg. 43 The Cow s Digestive System...Pg. 49 Texas Adapted Genetic Strategies for Beef Cattle X: Frame Score, Frame Size, and Weight...Pg. 56 Dehorning, Castrating, and Branding...Pg. 60 Implanting Beef Calves and Stocker Cattle...Pg. 63 Growth-Promoting Implants for Beef Cattle...Pg. 67 Value Added Calf (VAC) - Management Program...Pg. 75 Cattle Handling Pointers...Pg. 77 BQA Cattle Care and Handling Guidelines...Pg. 87 The Facts about Optaflexx TM : Ractopamine for Cattle... Pg. 111 Feedstuffs for Beef Cattle... Pg. 114 Mineral and Vitamin Nutrition for Beef Cattle... Pg. 126 Considerations for Retained Ownership of Feeder Cattle... Pg. 142

3 Economic Evaluation of Strategies to Reduce Feed Cost of Gain in the Feedlot... Pg. 144 How does the carbon footprint of U.S. beef compare to global beef?... Pg. 155 Does Beef Really Use That Much Water?... Pg. 157 If we fed corn to humans instead of cattle, would land use be more sustainable?.. Pg. 159 Is local beef more sustainable?... Pg. 162 Feedlot Health Series: Part 1- Receiving... Pg. 165 Feedlot Health Series: Part 2- Respiratory Disease Management... Pg. 168 Feedlot Health Series: Part 3- Bloat... Pg. 170 Feed Bunk Management for Maximum Consistent Intake... Pg. 172 Would removing beef from the diet actually reduce greenhouse gas emissions?... Pg. 183 Do growth promotants reduce environmental impact?... Pg. 186 Does grass-finished beef leave a lower carbon footprint than grain-finished beef? Pg. 188 Grass-Finished or Grain Finished Beef?... Pg. 191 Managing Heat Stress in Feedlot Cattle... Pg. 192 Hidden Costs in the Feedlot... Pg. 196 Matching Cattle Type and Feedlot Performance... Pg. 200 Marketing... Pg. 148 Ranchers Guide to Custom Cattle Feeding... Pg. 149 Factors Affecting Cattle Feeding Profitability and Cost of Grain... Pg. 154 Beef Cattle Marketing Alliances... Pg. 158 Retained Ownership Strategies for Cattlemen... Pg. 162 Grid Pricing of Fed Cattle... Pg. 166 Using a Slide in Beef Cattle Marketing... Pg. 171 Introduction to Futures Market... Pg. 173 Buying Hedge with Futures... Pg. 177 Selling Hedge with Futures... Pg. 181 Commodity Options as Price Insurance for Cattlemen... Pg. 185

4 Section 2: Quality & Yield Grading

5 BEEF QUALITY GRADING Beef quality grades are an indicator of overall palatability of an individual piece of meat. To determine a quality grade of a particular carcass, evaluations of maturity and marbling must be made. Step 1: Determining the Maturity Group A combination of two methods of maturation evaluation are utilized to determine the final quality grade. These are dentition and skeletal maturity. As an animal matures, the front incisors begin to protrude through the gum indicating an increase in age and this protrusion is utilized to classify the carcass as either over or under 30 months of age. This method of age verification is useful in determining the 30-month threshold due to its lack of interference by stress factors that can adversely impact skeletal maturity. For skeletal maturity, the cartilaginous (soft, white, pliable) connective tissue of the skeletal system is changed into bone (hard, dense, spongy) via the ossification process as the animal ages. Such changes occur in a definite sequence so that the relative degree of ossification (cartilage to bone) is a reliable indicator of maturity. Beef carcasses are divided into five maturity groups (A, B, C, D and E) based on the ratio of cartilage to bone, with A- maturity being the youngest classification. For example, A 30 means that the maturity is 30% across the range within A maturity. The following descriptions of each age group might be useful: 1. A maturity- a young carcass about 9-30 months of age at slaughter. 2. B maturity- a fairly young about months at slaughter. 3. C maturity the youngest carcasses to be considered old. These carcasses will be about months at slaughter. 4. D maturity- a fairly old carcass about months at slaughter. 5. E maturity- the oldest age classification. These carcasses are older than about 96 months at the time of slaughter. Lean maturity is another indicator of maturity. Lean maturity is based on the color and texture of the exposed ribeye. Lean maturity also is divided into five groups (A, B, C, D, and E). A carcass in the A- lean maturity group has a bright, cherry red color of lean with a very fine texture, while a carcass in the E- lean maturity group has a dark, almost brown- colored lean with an extremely coarse texture. To classify carcasses into one of these groups, we use three basic locations for bone (sacral, lumbar and thoracic vertebrae) and two criteria for lean (color and texture). In cases where clear decisions cannot be made from these criteria, other maturity factors should be considered. These other factors are color, shape and texture of the ribs; and condition of the split chine bones. Each of the vertebrae in the carcass consists of a body and dorsal spinous process. The vertebral column is divided into five sections (caudal, sacral, lumbar, thoracic and cervical). As an animal matures, distinct changes occur in the cartilage at the tips of each dorsal process in the sacral, lumbar and thoracic sections. The guidelines for beef carcass maturity evaluation in Table 9 should be learned and used for determining maturity scores.

6 Table 9. Beef carcass maturity guidelines Maturity Age, Best single indicator Other factors Score mo. A Sacral (distinct separation) Lean color & texture A Lumbar (partial separation) A Lumbar (70% ossified) B Upper 3 thoracic (0-10%) Lean color & texture ribs B Upper 3 thoracic (20%) B Upper 3 thoracic (35%) Upper 3 thoracic C Upper 3 thoracic (40%) Lean color and texture, ribs, evaluate hindquarter & chine bones C Upper 3 thoracic (40%) Other thoracic vertebrae, lean color color & texture ribs D Upper 3 thoracic (70%) E 00 >96 Upper 3 thoracic (90%) E 100 >96 Upper 3 thoracic (100%) Lean color & texture A majority of carcasses possess similar bone and lean maturity scores (i.e., a carcass of B 50 bone maturity is likely to have a lean maturity score of B 50 ). However, a discussion of beef carcass maturity would not be complete without a complete listing of the rules for determination of overall maturity. Rule 1: Rule 2: Rule 3: If skeletal maturity is C 00 or greater, the overall carcass maturity cannot be less than C 00 regardless of lean maturity score If skeletal maturity is B 85 to B 100 and lean maturity is C 50 or greater, overall carcass maturity is C 00 If skeletal and lean maturity vary by 40% or less of one score, overall carcass maturity is the arithmetic average of the skeletal and lean maturity scores. Always balance towards the bone score to avoid an odd final maturity score.

7 Rule 4: Rule 5: If skeletal and lean maturity vary by more than 40% of one score, then overall carcass maturity is the arithmetic average of the skeletal and lean maturity scores plus a 10% adjustment toward the skeletal score. If the skeletal and lean maturity vary by more than two full maturity scores, overall carcass maturity cannot vary by more than one full score from the skeletal score. Table 10 Examples of balancing skeletal and lean maturity scores Rule Skeletal Maturity Lean Maturity Overall Maturity 1 C 50 A 30 C 00 1 C 20 A 60 C 00 1 B 100 A 40 B = B 30 2 B 85 C 40 B B 85 D 50 C 00 3 A 90 B 30 B 10 3 C 50 C 20 C 40 4 B 60 A 80 B = B 30 4 A 50 C 50 B = B 40 4 E 50 D 50 E = E 10 5 C 00 E 50 D 00 5 E 50 C 20 D 50 Step 2: Determing the Marbling Score Marbling is the deposition of the intramuscular fat within the exposed surface of the ribeye muscle. Increased marbling is associated with increased overall palatability of cooked beef because of greater juiciness, tenderness and flavor. Because of this relationship, the final grade assigned to a beef carcass greatly depends on the amount and distribution of the marbling observed by the grader. As true of any scale, a continuum of scores can be established by using ten basic names for amounts of marbling. The specific scores in order of increasing marbling are: Devoid, Practically Devoid, Traces, Slight, Small, Modest, Moderate, Slightly Abundant, Moderately Abundant and Abundant. Step 3: Determining the Final Quality Grade Following a thorough understanding of the maturity and marbling scores discussed above, a grader must master the concept of balancing these scores for determination of the final quality grade along with dentition. One must first commit to memory the following rules and charts (Table 10 and 11). Rule 1: First check dentition to determine if the animal is over 30-months or not by teeth protrusion Rule 2: Carcasses deemed to be less than 30 months of age by dentition, with skeletal maturity of less than D00, are eligible for USDA Prime, Choice, Select and Standard Grades. (skeletal

8 maturity of A, B, and C when dentition is under 30 months are all considered A Maturity and follow the grading scale for A maturity outlined in Table 11) Rule 3: Any carcass that has a D00 skeletal maturity or higher, regardless of dentition, is considered old and are only eligible for USDA Commercial, Utility, Cutter and Canner grades (as outlined in Table 11 for D and E maturity carcasses) Rule 4: Carcasses deemed to be over 30 months of age by dentition will be classified using the skeletal, lean and overall maturity to determine a quality grade as outlined in Table 11 Rule 4A: If dentition indicates that the carcass is over 30 months and the overall maturity is B 00 to B 100 and the marbling score is Small or Slight, the overall quality grade is High Standard. Rule 4B: If dentition indicates that the carcass is over 30 months and the overall maturity is C00 or higher the carcass is considered old and is only eligible for USDA Commercial and Utility grades (as outlined in Table 11 for C, D and E maturity carcasses) Table 11. Relationship between maturity and marbling in determining final USDA quality grade for carcasses over 30 months by Dentition Maturity Marbling A B C D E Abundant Moderately Prime Abundant Slightly Abundant Commercial Moderate Modest Choice Small Slight Select Utility Traces Standard Practically Devoid Table 12. Marbling needed for hard-boned carcasses for dentition over 30 months Maturity Grade C D E High Commercial Md SlAb MdAb Average Commercial Mt Md SlAb Low Commercial Sm Mt Md High Utility Sl Sm Mt Average Utility Tr Sl Sm Low Utility Pd Tr Sl

9 BEEF YIELD GRADES In beef, yield grades estimate the amount of boneless, closely trimmed retail cuts from the high-value parts of the carcass--the round, loin, rib, and chuck. However, they also show differences in the total yield of retail cuts. We expect a YG 1 carcass to have the highest percentage of boneless, closely trimmed retail cuts, or higher cutability, while a YG 5 carcass would have the lowest percentage of boneless, closely trimmed retail cuts, or the lowest cutability. The USDA Yield Grades are rated numerically and are 1, 2, 3, 4, and 5. Yield Grade 1 denotes the highest yielding carcass and Yield Grade 5, the lowest. The USDA prediction equation for percent boneless, closely trimmed retail cuts (% BCTRC) of beef carcasses is as follows: % BCTRC = Minus 5.78 (Fat opposite the ribeye, in.) Minus 0.46 (Percentage KPH fat) Minus (Carcass weight, pounds) Plus 0.74 (Ribeye area, in. 2 ) Expected percentage of boneless, closely trimmed retail cuts from beef carcasses within the various yield grades YIELD GRADE % BCTRC < 45.5

10 Meat graders assign a yield grade to a carcass by evaluating: (1) the amount of external fat; (2) the hot carcass weight; (3) the amount of kidney, pelvic, and heart fat; and (4) the area of the ribeye muscle. Graders evaluate the amount of external fat at the 12th rib by measuring the thickness of fat three-fourths the length of the ribeye from the chine. They adjust this measurement to reflect unusual amounts of fat in other areas of the carcass. Only graders highly skilled in evaluating cutability of beef carcasses make these adjustments according to whether the measured fat thickness is representative of the fat coverage over the rest of the carcass. Carcass weight is the "hot" or unchilled weight in pounds (taken on the slaughter-dressing floor shortly after slaughter). The grader usually writes this weight on a tag or stamps it on the carcass. The amount of kidney, pelvic, and heart (KPH) fat is evaluated subjectively and is expressed as a percentage of the carcass weight (this usually will be from 2 to 4 percent of carcass weight). The area of the ribeye is determined by measuring the size (in inches, using a dot-grid) of the ribeye muscle at the 12th rib. The following descriptions will help you understand the differences between carcasses from the five yield grades: Yield Grade 1 - The carcass is covered with a thin layer of external fat over the loin and rib; there are slight deposits of fat in the flank, cod or udder, kidney, pelvic and heart regions. Usually, there is a very thin layer of fat over the outside of the round and over the chuck. Yield Grade 2 - The carcass is almost completely covered with external fat, but lean is very visible through the fat over the outside of the round, chuck, and neck. Usually, there is a slightly thin layer of fat over the inside round, loin, and rib, with a slightly thick layer of fat over the rump and sirloin. Yield Grade 3 - The carcass is usually completely covered with external fat; lean is plainly visible through the fat only on the lower part of the outside of the round and neck. Usually, there is a slightly thick layer of fat over the rump and sirloin. Also, there are usually slightly larger deposits of fat in the flank, cod or udder, kidney, pelvic and heart regions. Yield Grade 4 - The carcass is usually completely covered with external fat, except that muscle is visible in the shank, outside of the flank and plate regions. Usually, there is a moderately thick layer of external fat over the inside of the round, loin, and rib, along with a thick layer of fat over the rump and sirloin. There are usually large deposits of fat in the flank, cod or udder, kidney, pelvic and heart regions.

11 Yield Grade 5 - Generally, the carcass is covered with a thick layer of fat on all external surfaces. Extensive fat is found in the brisket, cod or udder, kidney, pelvic and heart regions. Step-Wise Procedure for Yield Grading Beef Carcasses 1. Determine the preliminary yield grade (PYG). Measure the amount of external fat opposite the ribeye. This measurement should be made at a point three-fourths of the way up the length of the ribeye from the split chine bone. Based on this fat thickness, a preliminary yield grade (PYG) can be established. The base PYG is The more fat opposite the ribeye, the higher the numerical value of the PYG. A carcass with no fat opposite to ribeye has a PYG of 2.00 For each.1 inch of fat add.25 to the PYG Fat opposite PYG ribeye Adjust for carcass weight deviations from 600 pounds. The base weight in the yield grade equation is 600 pounds. If a carcass weighs more than 600 pounds, then we increase the PYG, and if a carcass weighs less than 600, then we decrease the PYG. For each 25 pounds over 600 pounds, add.10 to the PYG For each 25 pounds under 600 pounds, subtract.10 from the PYG Carcass weight (lbs) Adjustment to the PYG No adjustment

12 3. Adjust for percentage KPH deviations from 3.5 percent. It has been determined that the average carcass has 3.5% KPH. If a carcass has more than 3.5% KPH, then the carcass is fatter than the average and the PYG should be adjusted up, raising the numerical yield grade. If a carcass has less than 3.5% KPH, then the carcass is leaner than average and the PYG should be adjusted down, thus lowering the yield grade. For each 1%KPH over 3.5%, add.20 to the PYG For each 1%KPH under 3.5%, subtract.20 from the PYG %KPH Adjustment to the PYG No adjustment Adjust for ribeye area (REA) deviations from 11.0 sq. in. The average carcass has a ribeye area of 11 sq. in. If a carcass has a ribeye area greater than 11.0 in., then it is probably more muscular then average, and the PYG should be adjusted down to lower the numerical value of the yield grade. If the ribeye area is less than 11.0 in., then the carcass is probably less muscular than average and the PYG should be adjusted up. For each 1.0 sq. in. over 11.0 sq. in., subtract.33 from the PYG For each 1.0 sq. in. under 11.0 sq. in., add.33 to the PYG Ribeye area (sq. in.) Adjustment to the PYG No adjustment

13 Example yield grade problem using the short cut method: Fat thickness: 0.5 in. Carcass weight: 750 lbs. %KPH: 2.0 REA: 14.0 sq. in. a. 0.5 in. = 3.25 b. 750 minus 600 = 150 / 25 = 6 *.1 =.6 (add) c. 3.5 minus 2.0 = 1.5 *.2 =.30 (subtract) d minus 11.0 = 3 *.33 =.99 (subtract) 3.25 PYG plus.60 Weight minus.30 KPH minus.99 REA 2.56 Final YG