Montana Beef Quality Assurance Certification Course

• Tutorial Main
• Introduction
  • Education Team
  • Intro to BQA
  • BQA History / Nat. Audits
  • 2005 Nat. Audit
  • Top 10 Industry Goals
  • Defining Quality Beef / Cattle Care
• Regional Curriculum
• Record Keeping
  • Effective Record Keeping
  • Information Recorded
• Care & Handling
  • Producer Attitude
  • Animal Behavior
  • Facilities & Transportation
  • Nutrition
• Feed & Additives
  • Feed
  • Additives
  • Handling / Monitoring
• Animal Health
  • Vaccines
  • Injections
  • Needles
  • Implants
  • Parasite Control
  • Antimicrobials
• Processing
  • Vaccinations
  • Dehorning & Castration
  • Identification
  • Weaning
• Carcass Quality
  • Quality Grade
  • Yield Grade
  • Other Quality Issues
• Marketing
  • Source & Age Verificiation
  • Market Timing
  • Cow Marketing
  • Feeder Calf Grades
  • Shrink
• Breeding & Genetics
  • Uniformity & Consistency
  • EPDs
  • Crossbreeding
• Biosecurity Basics
  • Disease Control
  • Learning Tough Lessons
  • Attention to Zoonotics
  • Agroterrorism
• Certification Process
• MT BQA Directives
• BQA Code
• Certification Exam

Funded, in part, by beef and veal producers and importers through their $1-per-head check off through the Cattlemen’s Beef Board and state beef councils by the National Cattlemen’s Beef Association.

Crossbreeding

Crossbreeding remains one of the most effective low–input, high–return management practices that a beef cattle producer can adopt. Effective crossbreeding is more than simply purchasing a bull and mating it to a cow of a different breed. Crossbreeding systems with varying degrees of complexity offer benefits in proportion to the increased management that they require.

There are two ways that crossbreeding can result in increased production levels:

1. Crossbreeding provides the breeder the opportunity of combining the desirable characteristics of two or more breeds, thus achieving a higher overall performance level of desired traits. This is frequently called breed complementarity, which refers to the strong points of one breed complementing or covering up the weak points of the other breed.
2. Crossbreeding increases productivity for particular traits due to heterosis (also called hybrid vigor). The whole can be greater than the sum of the parts. For instance, if straightbred Hereford and Angus calves average 500 lbs. at weaning and Hereford x Angus calves average 525 lbs., the heterosis realized is (525−500)/500, or 5%.

Crossbreeding Systems

The most commonly utilized crossbreeding systems in order from least to most demanding in terms of facilities and labor include:

• Two–Breed Cross
• Two–Breed Rotational Cross
• Three–Breed Rotational Cross
• Static Terminal Sire
• Rotational Terminal Sire

The ranking applies to the realized benefits; the two–breed cross is the easiest to manage but results in the least heterosis and little opportunity for breed complementarity. Some crossbreeding systems offer a greater degree of heterosis than others, and some traits respond more to crossbreeding than others. Use of artificial insemination (A.I.) or multiple breeding pastures is required for use of complex systems.

Maximizing Heterosis

Heterosis is realized in inverse proportion to heritability for a given trait. Lowly heritable traits offer the most heterosis and highly heritable traits the least. In general, reproductive traits are lowly heritable, growth traits are moderate and carcass traits are highly heritable.

Thus, differences in reproductive performance between herds are virtually all due to environment and management, while differences in growth or carcass traits are due primarily to genetics. Also, reproductive traits will respond the most to crossbreeding, carcass traits the least.

Before designing a crossbreeding system, the production environment and goals must be determined. A balance of traits is usually best and little progress will be made by a breeder who tries to select for everything at once.

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