Bovine- Dairy vs. Beef & AI

sihirlifil's version from 2017-09-27 15:51

Beef Cattle Reproduction vs. Dairy

Question Answer
Beef or dairy: AIDairy
Beef or dairy: Use of bulls for breedingBeef
Beef or dairy: Seasonal breedingBeef
Beef or dairy: year-round breedingDairy
How is synchronization and timed AI easier with dairy?Requires access to animals
Do beef operations use synchronization/timed AI?Intensively managed beef operations maybe
Beef or dairy: leader in genetic selection & AIDairy
Beef or dairy: scattered ability to track results of genetic selectionBeef
Stages of beef cattle productionCow-calf
Backgrounding (preconditioning, wintering…)
Veterinary services to beef cattle (cow-calf) operations (8)Pregnancy diagnosis
Bull BSE
Reproductive evaluation of heifers
Assisted reproduction
Vaccination program design
Implant/additive evaluation
Factors of postpartum anestrus length in beef cow herdBody condition (nutrition, lactational anestrus)
Range conditions
Major reproductive pathogens in both beef & dairy cattleIBR
Leptospira borgpetersenii ser. hardjo
Neospora caninum
Campylobacter fetus vererealis
Tritrichomonas foetus
Does venereal transmission happen in dairy operations?Not a factor in dairy operations that use AI exclusively
Calving season for beef cattle is timed for what?Calf survival & nutrition of dam
Calf marketing at weaning
Breeding season for beef cattle is timed for what?Produce calves in proper season
Breeding season in beef: heifer season may start earlier why?Pronounced postpartum anestrus doesn’t set cow back for 2nd season
What are beef bulls expected to do during breeding season?Naturally mate with all cows in heat multiple times per estrus
Conditions requiring longer breeding seasonPoor/unimproved/no pastures (free foraging)
Tropical geography
Long postpartum anestrus
Long gestation length

Artificial Insemination

Question Answer
Commercial bull studs: who owns the semen?The company owns & markets
Commercial bull studs: what is the company responsible for?Running performance testing of offspring
Custom stud: who owns the semen?The owner
Custom stud: who markets the semen?Bull owner (but custum stud may assist)
Dairy bull semen has a ___ marketRational
Worldwide system of distribution and agents
Dairy bull semen: most expensive isThe better performing & popular bulls
Beef bull semen: how is it marketed and distributed?Marketed by some commercial studs, but much of distribution is from custom stud or bull owner to user
Where does much of stored beef bull semen come from?“Vanity” freeze (bull owner has 1000 straws frozen and sells 20)
What does AI in beef cattle require?Additional facilities and management effort
When does AI make the most sense for beef cattle?Production of pure-bred breeding stock or major upgrade of genetics of herd
Most beef cows are bred how?By bulls
How many AI doses does a bull produce?Hundreds (spreads cost of freezing over hundreds of doses)
Why is freezing AI doses in nonruminant species costly?Only produce a few doses per ejaculate
Infrastructure of AI industry based on?Long-term storage
When a bull’s performance is proved, how is the industry affected?Demand for thousands of doses can be met from storage & regular collections
When a good bull dies, how is the industry affected?Remaining AI doses can still be marketed
Most common type of frozen semen package in USA1/2 CC straw
Why are AI doses packaged uniformly?Makes the industry work better
Types of frozen semen packaging worldwide?Glass ampule (generations outdate now)
1/2 CC & 1/4 CC straw
Liquid nitrogen (LN2) temperature =-196C
Dry ice temperature =-79C
Frozen semen is maintained at LN2 temperature becauseSuperior storage of frozen cells vs. dry ice
LN2 can be handled safely
LN2 tanks for storage of semen on farm areMetal vacuum bottles, no gas under pressure involved. Can hold for 6 months
Common components of semen extenders:Milk, egg yolk, glycerol
Purpose of semen extenders?Milk & egg yolk lipoproteins help protect spermatozoa during cooling
pH buffer
Isotonic solution- sugars often used
Freezing requirements: what do you have to do for milk or egg yolk proteins ?Allow time to interact with cell membranes
What is glycerol for as a component of semen extenders?Low molecular weight molecule used to modify how water freezes

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