Embedded Files
Overview & Preparation
Overview & Preparation
• Purpose: To evaluate the reproductive potential of bulls, especially those used for natural service in beef operations.
• Purpose: To evaluate the reproductive potential of bulls, especially those used for natural service in beef operations.
• Documentation: Specialized BSE forms are used to ensure a systematic examination and accurate reporting.
• Documentation: Specialized BSE forms are used to ensure a systematic examination and accurate reporting.
• Restraint: The bull should be safely restrained in a chute for the duration of the exam.
• Restraint: The bull should be safely restrained in a chute for the duration of the exam.
• History & Context: Dairy bulls are typically evaluated in specialized centers for AI, while beef bulls are evaluated for natural service.
• History & Context: Dairy bulls are typically evaluated in specialized centers for AI, while beef bulls are evaluated for natural service.
Physical Examination
Physical Examination
• General Health: Includes scoring body condition and inspecting the feet, legs, eyes, and sheath.
• General Health: Includes scoring body condition and inspecting the feet, legs, eyes, and sheath.
• Internal Genitalia: Palpation per rectum to check inguinal rings, ampullae, and vesicular glands (checking for conditions like seminal vesiculitis).
• Internal Genitalia: Palpation per rectum to check inguinal rings, ampullae, and vesicular glands (checking for conditions like seminal vesiculitis).
• External Genitalia:
• External Genitalia:
◦ Scrotum: Evaluated for skin health and symmetry.
◦ Scrotum: Evaluated for skin health and symmetry.
◦ Testes/Epididymides: Must be symmetrical, resilient, and freely movable; epididymides should have no palpable masses.
◦ Testes/Epididymides: Must be symmetrical, resilient, and freely movable; epididymides should have no palpable masses.
◦ Penis: Examined during extension (often during electroejaculation) for abnormalities like penile papillomas or deviations.
◦ Penis: Examined during extension (often during electroejaculation) for abnormalities like penile papillomas or deviations.
Scrotal Circumference (SC)
Scrotal Circumference (SC)
• Significance: A reliable predictor of testis weight, which estimates daily sperm production and quality.
• Significance: A reliable predictor of testis weight, which estimates daily sperm production and quality.
• Measurement: Taken with a flexible tape at the largest circumference while forcing testes to the bottom of the scrotum.
• Measurement: Taken with a flexible tape at the largest circumference while forcing testes to the bottom of the scrotum.
• Age-Specific Minimums:
• Age-Specific Minimums:
◦ < 15 months: ≥ 30 cm.
◦ < 15 months: ≥ 30 cm.
◦ 16–18 months: 31 cm.
◦ 16–18 months: 31 cm.
◦ 19–21 months: 32 cm.
◦ 19–21 months: 32 cm.
◦ 22–23 months: 33 cm.
◦ 22–23 months: 33 cm.
◦ ≥ 2 years: 34 cm.
◦ ≥ 2 years: 34 cm.
Semen Collection Methods:
Semen Collection Methods:
• Electroejaculation: Most common for routine BSE; uses a rectal probe to stimulate ejaculation.
• Electroejaculation: Most common for routine BSE; uses a rectal probe to stimulate ejaculation.
◦ Note: Samples are not representative of volume/concentration, but are equivalent for motility/morphology.
◦ Note: Samples are not representative of volume/concentration, but are equivalent for motility/morphology.
• Artificial Vagina (AV): Used in AI centers with bulls trained to mount a teaser; provides accurate volume and concentration data.
• Artificial Vagina (AV): Used in AI centers with bulls trained to mount a teaser; provides accurate volume and concentration data.
• Transrectal Massage: Massaging accessory sex glands; less successful and often results in lower semen quality.
• Transrectal Massage: Massaging accessory sex glands; less successful and often results in lower semen quality.
Semen Analysis:
Semen Analysis:
• Motility: Should be assessed immediately at ~37°C.
• Motility: Should be assessed immediately at ~37°C.
◦ Gross Motility: "Swirl pattern" in undiluted semen (rated Very Good to Poor).
◦ Gross Motility: "Swirl pattern" in undiluted semen (rated Very Good to Poor).
◦ Individual Motility: The proportion of sperm moving progressively; ≥ 30% is the minimum threshold (though some recommend 60% in optimal conditions).
◦ Individual Motility: The proportion of sperm moving progressively; ≥ 30% is the minimum threshold (though some recommend 60% in optimal conditions).
• Morphology: Evaluation of fixed or stained sperm under high power (1,000x).
• Morphology: Evaluation of fixed or stained sperm under high power (1,000x).
◦ Threshold: Must have > 70% normal sperm.
◦ Threshold: Must have > 70% normal sperm.
• Cytology: Checking for RBCs, WBCs, or immature germ cells which indicate tract abnormalities or degeneration.
• Cytology: Checking for RBCs, WBCs, or immature germ cells which indicate tract abnormalities or degeneration.
• Advanced Tools:
• Advanced Tools:
◦ CASA: Computer-assisted analysis used in AI centers for objective velocity and motion data.
◦ CASA: Computer-assisted analysis used in AI centers for objective velocity and motion data.
◦ Ancillary Tests: Evaluation of membrane integrity (eosin stain), mitochondrial function, or chromatin integrity.
◦ Ancillary Tests: Evaluation of membrane integrity (eosin stain), mitochondrial function, or chromatin integrity.
Behavioral Assessment
Behavioral Assessment
• Libido & Serving Capacity: Ideally assessed by observing the bull mounting and serving cows.
• Libido & Serving Capacity: Ideally assessed by observing the bull mounting and serving cows.
• Challenges: Often unfeasible during routine BSE; many bulls are declared satisfactory before suboptimal libido is discovered.
• Challenges: Often unfeasible during routine BSE; many bulls are declared satisfactory before suboptimal libido is discovered.
VII. Classification of Results
VII. Classification of Results
• Satisfactory Potential Breeder: Meets all minimum qualifications for physical health, SC, motility, and morphology.
• Satisfactory Potential Breeder: Meets all minimum qualifications for physical health, SC, motility, and morphology.
• Unsatisfactory Potential Breeder: Fails to meet minimum criteria or possesses undesirable heritable traits like cryptorchidism.
• Unsatisfactory Potential Breeder: Fails to meet minimum criteria or possesses undesirable heritable traits like cryptorchidism.
• Classification Deferred: Results are marginal or questionable; a retest is recommended.
• Classification Deferred: Results are marginal or questionable; a retest is recommended.
Page updated
Google Sites
Report abuse