Livestock breeding – modelling, genetic modification and gene editing

Last changed: 06 July 2017
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Livestock breeding is a long-term process in several steps where one strives to improve various properties. Modelling is a tool used to predict the results of the effects of breeding. Simulation models can also be used to compare different methods in order to improve livestock genetically.

Modelling of resource allocation and feed efficiency 

The breeding goals can, for example, mean that the intention is to improve the animal's ability to utilise food and how the nutrients are allocated (resulting in, for example, heat, milk, growth, immunity, etc.). Today's breeding goals for livestock are formulated as quantifiable traits, such as the amount of milk produced, occurrence of disease and reproductive capacity. This methodology does not, however, take into account the changes that occur within each individual over time. Different factors such as environment, feed and diseases can affect the traits, and complicate the calculation of the effects of breeding.

We construct mathematical models of the resource allocation and feed utilisation, and then use these models to examine the consequences of breeding with different objectives. We use existing models for resource allocation which are extended to also include hereditary variation within certain key traits, as well as nutritional models that describe the digestive process.

Contact: Freddy Fikse and Dirk jan de Koning

Livestock breeding – modelling, genetic modification and gene editing

The development of techniques to produce genetically modified (GM) and gene-edited animals has paved the way for new opportunities within livestock breeding. Besides traditional GM techniques such as genetic transfer, gene-editing techniques such as TALEN and CRISPR/Cas9 are now being used to alter to the genetic material. These new, more precise techniques provide new possibilities to include animals produced using gene-editing techniques in breeding programmes. However, we also need to make an in-depth analysis of the consequences and the ethical aspects that such an introduction gives rise to.

In this project we simulate various scenarios, based on specific examples (see below), in order to test how GM animals and gene-edited animals could be introduced into the breeding programmes. We have chosen these examples as they are well-defined and differentiated regarding the species of animal, method and breeding objectives – they imply different questions from a genetic and ethical standpoint.

  • Dairy cows – increased resistance to udder inflammation (improved animal health, reduced suffering, financial gain, reduced use of antibiotics)
  • Pigs – resistance to new diseases, for example African swine fever (reduced risk to Swedish pig production) 

The results will indicate the advantages of the different techniques, but they will also reveal bottlenecks and resultant inbreeding, potential risks to human and animal health and risks to the environment. We will find out how many animals are needed in the breeding process, financial costs and possible benefits. We are also examining what will happen following the introduction of the genetically modified animal – how it will be integrated into the population. We identify different ethical aspects in each respective case, and we evaluate the consequences of various breeding strategies. We compare gene editing, conventional breeding and GM based on the possibilities and opportunities that each method offers. The opinions of both farmers and the general public are important to the project, and we will be promoting debate on ethical aspects of the use of modern techniques in livestock breeding during various activities within Mistra Biotech (seminars, workshops, etc.).

Contact: Elisabeth Jonas

Page editor: anna.lehrman@slu.se