Course: Principles of AFNR Unit Title: Sheep Selection TEKS: 130.2 (C)(12)(D) Instructor: Ms. Hutchinson Objectives: After completing this unit of instruction, students will be able to: A. List important areas to think about when selecting sheep; B. Describe what to look for in structural correctness; C. Explain why we need a structurally correct mouth; D. Explain what type of performance data we look at when selecting for ewes; E. Select the top 5 ewes when looking at the performance data for 8; F. List the fleece characteristics to look for when selecting sheep; G. Explain 5 ideal characteristics when judging market lambs; H. Describe what the hindsaddle is; I. Explain how to handle a lamb; J. Describe a lamb that is too thin; K. Describe a lamb that is correctly finished; L. Describe a lamb that is over finished; M. Explain how much an ideal market lamb should weigh; and N. Label the wholesale cuts of lamb.
Interest Approach: By being able to select quality sheep by visual inspection, the producer, breeder, and consumer all benefit. Discuss ways in which the student and their families will benefit. Selection principles apply to agricultural student SAE projects. Encourage students in the class who are maintaining sheep enterprises to discuss these projects with the class. Curriculum & Instruction: Curriculum Select for Lamb or mutton production Wool production Feedlot Market (including show lambs) Meat Production Heavy weaning lambs of acceptable grade and type Wool Production Clean weight and quality fleece are more important Feeder Lambs Desirable type and quality, health and vigor, and performance in the feedlot Market Lambs Conformation, finish, and quality and yield of carcass A. List important areas to think about when selecting sheep; Basic Factors for Selection: Body conformation and wool Production Records Pedigree Health and Vigor Instruction PPT Slide 4-6 What are the decisions we need to decide before we start selecting our sheep? PPT Slide 7-17 What are the basic factors for selection? Other Important Areas: Structural Correctness Frame Capacity Body composition Head Neck Shoulders
Mouth Soundness The profitable breeding sheep is structurally and reproductively sound, highly productive, and can gain rapidly and efficiently. Many of the characteristics to consider when evaluating breeding cattle and swine are applicable to breeding sheep. This is also true of the market lamb areas of emphasis on muscling and leanness. B. Describe what to look for in structural correctness; Structural Correctness: Legs should be straight, strong, and set wide apart on the corners of the body Walk with a long, free stride Allows them to adapt to range conditions Long, sloping shoulder, level rump, and correct positioning of the feet and legs Allows for freedom of movement Describe a structurally correct lamb. Frame: Important genetic factor Economical to maintain moderate-sized ewes Breed these ewes with larger frames rams to get market lambs of a desirable size and weight Capacity: Sprung in upper rib region and deeply ribbed Stand wide and have ample width through the chest floor Excess fat and condition creates an illusion of increased body capacity Describe correct body capacity in a lamb.
Body Composition: Heavily muscled with minimum amount of fat cover Good body composition and strong eye appeal Desirable body composition for breeding lambs is the same for market lambs Head, Neck, and Shoulders: Late maturing sheep have relatively long neck and head Broad forehead and ample width between eyes Ewe s head should be more refined than a ram s Ewe Ram Muscled, yet join neatly with top and blend in smoothly with the neck Coarse, prominent shoulders can cause lambing difficulties if inherited by offspring C. Explain why we need a structurally correct mouth; Mouth Soundness: Sound mouth and normal jaw Jaw should meet squarely and the incisor teeth in lower jaw should be centered on the dental pad in the upper jaw Jaw defects are highly heritable! May prevent gathering adequate forage Why should we care about a sound mouth and normal jaw? Jaw Structure:
D. Explain what type of performance data we look at when selecting for ewes; Female Selection: EPDs and Performance Records are not used extensively in the sheep breeding industry Performance data may be used in Career Development Events DOB, Weaning Weight, Type of Birth & Rearing, fleece weight and spinning count Weaning Weight indicator of growth and feeding efficiency Type of Birth Prediction of fertility Type of Rearing reared alone or with rearing mates because twins are preferred to single births in most sheep operations, the listing of multiple births is desirable. PPT Slide 18-20 When do we normally pay attention to performance records of sheep? What information can you find in a sheep s performance record? E. Select the top 5 ewes when looking at the performance data for 8; Pick the top 5 Ewes: 4, 5, 6, 7, and 8 Fleece Quality Evaluation: Fleece quality is not important for market lambs Breeding sheep production 2 products: meat, and wool PPT Slide 21-26 What two products can we raise sheep for?
Medium-wool fleece should be evaluated for presence of any black fiber or kemp Kemp is a chalky, white fiber that is hollow and does not dye well What is kemp? Why do we not want any black fibers or kemp in the wool? F. List the fleece characteristics to look for when selecting sheep; Fleece Characteristics: Fineness Staple Length Belly Wool Density General Appearance Face wool What fleece characteristics do we look for? Fineness, Length, Belly Wool: Coarse fibers at shoulders and rump Look for uniformity of fleece throughout! Where is our lowest quality wool found on a sheep?
Meet staple length requirements! Fine-wool = 2.75inches or longer Belly wool is short and less desirable Undesirable if this wool carries up high on the side Open fleece of belly and work upward on the side to detect how far the belly wool carries Density, Appearance, and Face Wool: Density is determined by opening the fleece and handling the wool Number of fibers per square inch of body surface Tip of fibers will probably be dirty, but the remaining should be bright, white and free of any colored fibers or kemp Open face ewes are more desirable Extra management with too much wool over the eyes Evaluating and Judging Market Lambs: Major attention at: Muscle Finish Length Type Size and evidence of growth rate should be considered Why do we not want face wool? PPT Slide 27-35 Where is my our most attention at when evaluating and judging market lambs? Parts of a Lamb: G. Explain 5 ideal characteristics when judging market lambs; Ideal Characteristics of a Lamb:
Market Lambs: Major Consideration: Muscle Balance Correctness of finish Ideal lamb is heavily muscled and has a minimum amount of fat Thick and meaty through: Loin Rump Leg regions What are the ideal characteristics of a lamb? Head Neck Shoulder Chest Back Loin Rump Legs Body finish Describe an ideal lamb. H. Describe what the hindsaddle is; Hindsaddle should have a high percentage of a sheep s weight Loin and leg combined Highest priced retail cuts The loin should be deep, as well as wide, and the leg should be expressively muscled. Where is most of the sheep s weight suppose to be? Market: Trim in breast, middle, flank, and forerib Fullness in these areas indicate excess fat and condition
Rib and loin should have a muscular shape to its top I. Explain how to handle a lamb; Handling Market Lambs: Allows to properly assess the amount of muscling and finish Excess fat is undesirable! Always keep fingers together to get the proper feel Start at the front and handle down the top towards the rear of the lamb Feel how much finish or fat cover is over the loin Measure actual width of top to determine amount of muscling or loin eye muscle More width and expression, coupled with leanness = desirable! Explain how to handle a lamb. What are we looking for while handling market lambs? PPT Slide 36 PPT Slide 37 Every lamb should be handled in the same manner to make proper comparisons between each lamb. J. Describe a lamb that is too thin; Too Thin: Very prominent of sharp backbone Each rib will be sharp and very easy to feel PPT Slide 38-40 Describe a lamb that is too thin,
Hollow feeling between each rib K. Describe a lamb that is correctly finished; Correctly Finished: Backbone can be easily felt but is not sharp Ribs can be felt but are not sharp to the touch No hollow feeling between the ribs Describe a lamb that is correctly finished. L. Describe a lamb that is over finished; Too Fat: Handle very smooth over the top with the backbone not easily felt Ribs can be felt, but it will not be easy to distinguish between each rib When handling for muscling, primary attention should be given to the length of the hindsaddle and rump and the circumference of the leg. Describe a lamb that is too fat. PPT Slide 41 When measuring the hindsaddle, check the length from the last rib to the base of the dock. PPT Slide 42
Also check the length, width, and depth of loin, as well as, the length and width of the rump. PPT Slide 43 The leg should be handled for depth and volume of muscle, making sure to measure the leg s circumference. PPT Slide 44 How do you measure the circumference of a sheep s leg? M. Explain how much an ideal market lamb should weigh; and Live Weight: Weights range from 100 to 160lbs Desirable market lambs weigh between 120 and 135lbs Desirable to gain at a fast rate, yet maintain acceptable leanness at the ideal slaughter weight PPT Slide 45-50 What is the ideal market weight? N. Label the wholesale cuts of lamb.
Label the wholesale cuts of lamb. Students are to draw and label the diagram above in their notes. Wholesale Cuts: Need to be free of excess fat More muscle = more total marketable product = more $$$ A Muscular and Correctly finished Lambs:
An underfinished and poorly muscled lamb: 1. Weak-topped 2. Smaller-framed 3. Shorter-sided 4. Sloped rump 5. Flat muscle pattern, lacks expression 1. Narrow over top 2. Less expression of leg muscling 3. Less total volume of muscle (concave appearance) Estimating Age: PPT Slide 51 How should the teeth look for a lamb that is about 18-24 months of age? Udders: Two halves that are free of knots Teats adequate in size, not too large for lambs Not pendulous so that it could be injured by the legs and brush Testicles: Free of knots Evenly sized Descend from body wall PPT Slide 52-53 Describe a ewe s udders. Describe a ram s testicles. Students will be split into groups. I will place a placing class of lambs on the screen for them as a group to decide how they would place the class and why. After giving the groups about 15 minutes to look over the sheep we will go around the room
hearing the reasons behind why each group picked the sheep they choose. I will then tell the students the way I placed them and why. I will take a grade on this assignment, and students who give answers like because it s pretty or any other response that is not a dignified answer their grade will reflect on it. I will help the students if they are stuck on where to start looking at first when placing their class. If this lesson is done before the SAE projects are sold, I will bring live lambs to the classroom so the students can practice feeling a lamb and selecting a class in that manner as well. Independent Practice: Students will be given another set of lambs to select and they will write down their placing and the reasons for the way they placed the sheep. Review & Instruction: Objectives will be reviewed before examinations. Exams will be developed based on objectives as taught in class. Instructional Support: A. References a. IMS Online Curriculum b. Colorado Agriscience Curriculum c. www.livestockjudging.com B. Teaching Aids & Equipment: a. Sheep Selection PPT b. Sheep Selection Student PPT c. Livestockjudging.com market lamb classes d. Sheep Selection Test Review e. Sheep Selection Test C. Facilities: a. Agriculture classroom