Published on Feb. 1, 2022
The impact of 2% progress in swine genetics
Our swine breeding program is geared towards delivering healthy, self-reliant animals that continuously improve with every new generation. 2% may seem small. But in the right context, 2% can make a huge impact.
Genetic progress or improvement is defined as the progress that is made when the average genetic value of the offspring is higher than the average genetic value of the previous generation. So simply put, increasing the rate of genetic progress is about making better pigs, faster. Today, we highlight genetic progress and what you can expect from our champions.
The three factors of genetic progress
The amount of genetic improvement obtained in each generation of selection depends on three factors:
- Accuracy of the phenotypic evaluation or the performance records in predicting the animal’s true breeding value or genotype.
- Intensity or degree of selection based on the phenotypic evaluations practiced on animals.
- Amount of genetic or true breeding value variation among animals for the trait under selection.
Note that if any one of these factors is equal to zero, the product of the calculation is zero, indicating that no genetic progress can be expected regardless of the size of the other two factors.
Genetic progress can occur regardless of the type of management, feed or facilities used in a farm and/or system. Genetic improvement does not result from changing the management, facilities, feeds, etc., even though, by making such changes, the herd average for a particular trait may improve. The reason is that changing these environmental factors does not change either the genes carried by the animals or the genotypes obtained from these genes; therefore, genetic improvement will not result.
Genetic improvement brings tangible benefits to profitability, the genetic gains are additive, i.e. progress made this year will still be there next year and the years after. Although small genetic improvements might go unnoticed in the short term, because of their additive nature, in the long run these improvements will become visible. For example, an improvement of 0.03 in feed conversion might not be visible when comparing subsequent years, whereas when this is being looked at for a longer period it will be visible. Compound interest is sometimes referred to the 8th wonder of the world, genetic improvement falls in the exact same category!
Animal selection is a powerful tool
The genetic improvement of animals is an essential component of sustainability. Although most people are unfamiliar with how the genetic improvement of animals is achieved, they are well aware that their pets look and behave nothing like their ancestors. Selection is a powerful tool, and animal breeders have employed that tool to breed more productive and resilient animals. This has decreased the environmental resources required per unit of product dramatically. Innovations such as artificial insemination and genomic selection have all significantly increased the rate of genetic gain in animal breeding programs.
More efficient animals have a positive impact on the land use, animals that eat less (require less input) and lead to reduced land use. Calculating feed conversion rates in a different way, using the quality of the diet, manure composition, and the percentage of pig losses from start to finish, will contribute to the discussion of what is sustainable conversion.
Historic advancements in pig breeding
Genetic improvement in pigs during the 20th century was considerable with the development of objective trait measurements, use of breeding values, crossbreeding and the development of commercial lines of swine that grew quickly, efficiently and produced more piglets. The close of the century brought the creation of genetic maps and the discovery of important genetic markers and their use in marker assisted selection for traits of economic importance. Such discoveries and their application to the industry have made the pig a major source of lean red meat.
Efforts in the early part of the 21st century have been amazing. The initial sequencing efforts are now completed; the development of SNP (single-nucleotide polymorphism) chips and the advent of genomic selection are beginning to revolutionize pig breeding. It is likely that with these new genomic tools, advances to select disease resistant pigs will be more successful. It is expected that fine tuning of breeding programs to match specific environments as well as specific niche markets or the production of specialized products will also occur.
Pig breeders, producers and consumers will all benefit from these advances in genetics and genomics and the resulting genetic improvement. This will require adoption of technology, advanced training by many within the livestock industry and education of the public of the safety of these advances.