Physical Evaluation of Bulls
5.3.2. Physical Evaluation of Bulls
Evaluating bulls intended for use in a breeding program is an essential part of the breeding process. To determine how well bulls are equipped to be successful breeding animals, an assessment of four major factors is required. Each of these factors inluences the fertility of an individual bull. The four main factors are: • Physical or structural soundness of the animal • Scrotal circumference and tone • Semen quality • Ability and desire to mate. For a bull to successfully pass an evaluation the bull must: • Pass a physical examination of the important structural components legs, feet, penis and sheath prepuce • Meet minimum requirements for scrotal circumference refer Section 5.3.5. and have a irm tone not soft or hard • Semen testing must show at least 30 of sperm are motile moving and sperm cell morphology must exceed 50 normal for natural mating in multiple sire groups, and exceed 70 normal for single sire mating or if intended for use in an artiicial insemination AI program • Show both the desire libido and ability to physically mount and mate with a cow. A bull must meet these minimum criteria in all categories to pass an evaluation. These criteria are relatively easy to test as outlined in 5.3.3 - Structural Soundness and Body Conformation. The main reasons why bulls are culled include: Arthritis - about 50 of bulls are culled because of loss of mobility due to arthritis. Arthritis is caused by poor leg and joint structure. Grain feeding of bulls as yearlings accelerates the onset of arthritis and joint problems. Injury - caused through ighting, accounts for about 10 of bull wastage. Broken penis - 15. This problem is usually found in bulls in their irst season, or in older bulls as arthritis begins to afect serving ability. Poor serving ability caused by structural problems particularly straight hind legs is the major cause of a broken penis. Corkscrew penis - 15. The penis corkscrews as the bull mounts, making service diicult if not impossible. This condition often only appears when a bull is 3-4 years of age, and gets worse as the bull gets older. Sheath problems - prepuce or sheath infections account for about 5 of bulls culled. Pendulous sheaths contribute to sheath problems. Overgrown feet - 5. Feet defects such as scissor claw and uneven toes are inherited feet problems - overgrown feet is generally a sign of poor leg structure. 129 Cold Winter Climates5.3.3. Structural Soundness and Body Conformation
Parts
» LEP Cold Climate Beef Breeder Manual 2016 (English).
» Importance of Planning LEP Cold Climate Beef Breeder Manual 2016 (English).
» Timing Trained Staff Planning for Arrival
» Quarantine Facilities Water on Arrival
» Management of Health on Arrival Feeding on Arrival
» Winter Feeding Planning for Arrival
» Monitoring In Quarantine General Health and Husbandry
» Arrival Checklist Planning for Arrival
» Paddocks and Fencing Developing the Property
» Cattle Yards Developing the Property
» Raceways Loading and Unloading Ramps
» Laneways Gates Developing the Property
» Yard Posts Electronic Scales Crush and Head Bail
» Water Troughs Developing the Property
» Modernising Traditional Winter Facilities
» Winter Confinement Feeding Sites
» Confinement Yards Winter Facilities
» Planning Requirements On-Farm Fodder Storage
» Ruminant Digestive System LEP Cold Climate Beef Breeder Manual 2016 (English).
» Feed Intake The First Limiting Nutrient
» Digestibility Fibre Concepts of Nutrition and Feeding
» Vitamins Nutrient Balance Essential Nutrients
» Water LEP Cold Climate Beef Breeder Manual 2016 (English).
» Moulds and Mouldy Feeds Cold Weather Impacts on Feed
» Body Condition Scoring Observational Skills
» How to Recognise Sick Animals
» Healthy Animal Behaviour Reading Manure Early Diagnosis and Treatment
» Prevention Rather than Treatment Nutritional Stress
» Understanding the Animal Welfare Requirement Features of Sight
» Flight Zones Education and Training
» Moving Animals Safe, Low Stress Cattle Handling
» Euthanasia Safe, Low Stress Cattle Handling
» Understanding the Animal Welfare Requirement Preventing Injury
» Features of Suitable Cattle Transport
» Preparing Animals for Transport Loading
» Loading Density In-Transit Care
» Unloading Transporting in Extreme Weather
» External Parasites Common Cattle Diseases
» Internal Parasites Common Cattle Diseases
» Diseases Affecting Reproductive Performance
» Clostridial Diseases Common Cattle Diseases
» Other Important Diseases Common Cattle Diseases
» Bloat Common Cattle Diseases
» Australian Health Status Developing a Breeding Objective
» Selecting the Most Appropriate Breed
» Crossbreeding With Local Breeds - Beef and Dairy
» Physical Evaluation of Bulls
» Structural Soundness and Body Conformation
» Penis and Prepuce Scrotum and Testicles
» Semen Sample Ability to Mate Serving Capacity
» Bull Management and Preparation for Mating Bull to Cow Ratio
» Reproductive Organs Oestrus Cycle and Heat Detection
» Mating After Calving Using Artificial Insemination in the Reproductive Cycle Pregnancy Detection
» Preparations for Calving Calving Management
» Abnormal Calving Calving Management
» Failure to Conceive Culling Unproductive Cattle from
» Failure to Produce a Live Calf Failure to Raise a Calf to a Healthy Weaner
» Cast-for-Age Culling Unproductive Cattle from
» Selecting Replacement Breeders Heifers
» Targets for Heifer Development
» Selecting Appropriate Sires for Heifer Mating First Calving
» Relationship Between Feeding LEP Cold Climate Beef Breeder Manual 2016 (English).
» Animal Identification Calf Processing
» Castration Dehorning Calf Processing
» Early Weaning Feeding Weaner Cattle
» Adaptation of Australian Cattle
» Winter Management Essentials LEP Cold Climate Beef Breeder Manual 2016 (English).
» Bedding Managing the Welfare of Cattle in Winter
» Water Managing the Welfare of Cattle in Winter
» Feeding in Confinement Opportunities to Manage Cattle
» Winter Grazing Opportunities to Manage Cattle
» Managing Winter Grazing Opportunities to Manage Cattle
» Grazing Stockpiled Forage Swath Grazing
» Bale Grazing Opportunities to Manage Cattle
» Developing a Winter Feed Budget
» Traditional Indoor Winter Backgrounding
» Finishing LEP Cold Climate Beef Breeder Manual 2016 (English).
» Plant Adaptation Forage Species
» Legumes Forages in Farming Systems
» Grasses Forages in Farming Systems
» Selecting the Right Species Anti-nutritional Factors
» Preparation for Sowing Seed Quality
» Area Required Stocking Rate Grazing
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