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