Crossbreeding Systems
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Transcript of Crossbreeding Systems
Crossbreeding Systems
You shall keep my statues. You shall not let your cattle breed with a different kind;…
Leviticus 19:19
Breeding Scheme Design
• Crossbreeding– One of the few “Free” things in beef production
• A crossbred cow returns about $90/year more than a straight-bred cow.
• A crossbred calf returns about $70/head more than a straight-bred calf.
Evaluating Crossbreeding Systems
• Use seven criteria:1. Merit of component breeds
2. Hybrid vigor
3. Breed complementarity
4. Consistency of performance
5. Replacement considerations
6. Simplicity
7. Accuracy of genetic prediction
Merit of Component Breeds
• Each breed must bring favorable attributes to the mix– Would not choose Longhorn if having polled,
heavy muscled cattle was important
Hybrid Vigor
• The most important reason for crossbreeding
• Find a system that maximizes hybrid vigor
Breed Complementarity
• Big Bull x Small Cow theory– Sire x Dam Complementarity
• Choose a maternal breed type for females
Consistency of Performance
• Produce as consistent of calf crop as possible
• Some systems do a better job at this
Replacement Considerations
• The ultimate female is an F1
• How does the system produce females?– Can it produce F1 females?
Simplicity
• KISS principle should apply
• It is very easy to overcomplicate production
Accuracy of Genetic Prediction
• Higher the accuracy of prediction, the lower the selection risk– More predictable offspring
• EPD’s are a great tool to increase Accuracy of Selection
Types
• Rotation– Space– Time
• Terminal– Static– Rota-terminal
Spatial Rotation
Rotation in Time
Simple Terminal
Complex Terminal
Rota-terminal
Heterosis
System Attributes
System HV Comp Consistency Replacements Ease Accuracy
Two Breed Spatial
+ - Varies + + +
Rotation in Time
+ + Varies + ++ -
Static Terminal
++ ++ + - ++ +
RotaTerminal + + Varies + - +
Questions