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21 Cards in this Set
- Front
- Back
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What are the justifications of the Bull BSE?
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1. Eval potential fertility prior to sale
2. Eval fertility of individual bulls prior to introduction to herd/ periodically 3. Eval bulls as a potential source of infertility (subfertility in bulls is associated with delayed conception) |
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What is the accuracy of the bull BSE?
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Very reliable for detecting bulls with increased potential fertility and unsatisfactory bulls
Approx. 15-20% of unselected bulls don't pass a BSE |
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What does the BSE test?
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1. Does the bull have the goods (good quality semen)
2. Does he have the ability to deliver the goods? (PE) 3. Does he have the desire to deliver the goods? (Libido) |
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What are the steps of the bull BSE?
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1. ID the bull and owner
2. Physical exam: Soundness, freedom from disease 3. Repro tract evaluation: palpation of external/internal repro tract, collect and evaluate semen |
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What does the external Repro tract exam consist of?
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1. examine prepuce
2. Palpate and observe scrotum and contents |
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Why do we measure scrotal circumference?
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Is highly correlated with fertility.
Testis weight is correl with daily sperm production Tells about semen quality Circumference of bulls 1-2 years old is highly heritable Yearling bulls with a small SC don't "Catch Up" |
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How do you evaluate the internal reproductive tract of a bull
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1. palpate the vesicular glands, prostate, inguinal rings
2. massage the base of the penis |
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How do you collect Semen via an electoejaculator?
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1. Place electroejaculator intrarectally with 3 electrodes pointing ventrally
2. Collect semen when turns to slightly opaque/milky consistency |
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How do you evaluate semen for gross motility vs. individual motility
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View undiluted semen at low power for gross motility, and view diluted semen (with sodium citrate or saline) with a cover slip for individual motility
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What is individual motility correlated with in the bull BSE?
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Is highly correlated with % live sperm and since % live sperm is no longer included in the semen evaluation, progressive motility needs to be accurately assessed.
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How much progressive motility is required for the bull to pass?
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> 30%
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Why are morphologically defective sperm bad for fertilization?
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Morphologically abnormal sperm are impaired at the cervix, uterus, uterine tubal junction, and the isthmus of the uterine tube and by the vestments of cells surrounding the ovum thus resulting in fewer sperm accessing the ovum
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What percentage of morphologically normal sperm are needed to pass the BSE?
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>70%
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How do you assess sperm morphology in the bull BSE?
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Stain with Eosin-nigrosin stain (very hypotonic, dry slides quickly)
Examine using 1000-1250X Classify ~100 spermatozoa as: 1. Normal 2. Primary defect (originating in the testis) 3. Secondary defect (originating in the epididymis) |
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What are compensable sperm defects?
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Defects that can be compensated for by increasing the total sperm per insemination dose and achieving greater fertility.
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What are uncompensable defects?
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Sperm that reach the ovum and penetrate the vestments but cause either fertilization failure or formation of an embryo that develops abnormally and is subject to increased early embryonic failure/death
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What are the pros and cons of using an artificial vagina to collect semen?
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Pros: quantity and quality of semen is thought to be best through this collection method
Cons: Increased injury to human handlers and animals, difficult in animals not frequently handled |
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What are some penile/scrotal abnormalities that would disqualify a bull?
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1. Penile Deviation
2. Hair ring 3. Fibropapilloma 4. Testicular degeneration 5. Scrotal enlargement 6. Bilateral testicular hypoplasia |
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What is the cause of penile deviation?
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Weakness in the apical ligament of the penis-- "Rainbow avulsion"
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How does a hair ring occur?
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Young bulls housed together mounting eachother
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What causes scrotal enlargement?
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Low protein/ peritonitis between the parietal and vaginal tunics
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