4.02 - A practical approach to breeding
When designing a crossbreeding program, it may be wise to seek professional help. There is a course, developed by MLA, specifically for designing breeding programs. This includes a major section on crossbreeding that could provide valuable assistance with the design of a crossbreeding program. The “More Beef from Breeding” course is designed to support More Beef from Pastures clients who want to study beef breeding in more detail.
How breeding systems can exploit genetics
Forming the right breeding program design is important to reaching your goals. The potential within breed and between breed gains that can be achieved are detailed in Table 5 with considerations for breeding program design displayed in Table 6.
Table 5: Sources of genetic differences
| Economically important traits | Within breed* | Between breeds** | Hybrid vigour*** | |||
| British (BB) | European (E) | Bos indicus (BI) | BB/BB or BB/E | BB/BI or E/BI | ||
| Growth | ✔ | ✔ | ✔✔ | ✔✔ | ✔ | ✔✔✔ |
| Reproduction | ✔ | ✔ | ✔ | ✔ | ✔ | ✔✔ |
| Yield (carcase quantity) | ✔ | ✔ | ✔✔✔ | X | 0 | 0 |
| Marbling (carcase quality) | ✔ | ✔ | X | X | 0 | 0 |
*Selecting the best within one breed – the variation is calculated as the top 10% of the breed compared to the bottom 10% in a group BreedPlan summary
**Determining if there is a better breed for the key profit factors (these figures assume starting with a British breed base).
***Determining if the crossbred animal is superior to the average of the two parent breeds.
- ✔ represents approximately 5% gain
- ✔✔ represents approximately 2.5% gain
- ✔✔✔represents a 5% loss in desired trait
- 0 represents no gain
Table 6: Potential to change key factors for a southern production system tailored to a longfed export market.
| Trait | ||||
| Liveweight (point of sale) | Weaning rate | Carcase yield | Carcase quality | |
| Relative importance of trait* (1 = most important) | 2 | 3 | 4 | 1 |
| Within breed selection feasible** | ✔✔✔ | ✔ | ✔✔✔ | ✔✔ |
| Selection criteria | Yes 600 day 20kg above breed average |
Scrotal size EBV above breed average | No EMA EBVs below breed average |
No |
| Between breed opportunities | Yes | Yes | Yes | Yes |
| Between breed opportunities being exploited | No | No | No | No |
| Hybrid vigoour would help | ✔✔✔ | ✔✔ | X | X |
| Hybrid vigour being exploited | No | No | No | No |
| Suggested actions | BreedObject | Look at EMA EBVs | IMF EBVs - new to breed*** | |
*Indexing programs such as BreedObject, assist to determine the relative importance of traits more accurately.
**The trait is heritable.
***As marbling is the most important factor, any change in breeding system would have to ensure no loss of marbling performance. Crossbreeding with Shorthorn or Wagyu could be considered.