The Economic Consequences of Reciprocal Translocations (RTs) in Global Pig Breeding and the Benefits of Using a Novel "Multiprobe" Approach as a Standard Screening Methodology

Pig protein remains the most popular worldwide, representing >30% of all consumed meat; a figure that is expected to rise from 106 to 127 metric kilotons per year in the next 10 years. As the market and demand for pig meat continues to grow across the world, so does the importance of its sustainability and its economic accessibility. With this in mind, great focus and attention is turning to reducing food and protein chain waste as a means of both environmental stability and improving economic growth/productivity (FAO 2020). Food loss at all levels from the level to consumer leads not only economic loss, but also lack of food available to consumers. In order for businesses to combat chain wastage and improve profits, behavioural change among the different levels is necessary, but it can also be prevented through innovation and technology. A major biological issue that causes the pig industry problems is that of chromosomal reciprocal translocations (RTs), which are relatively common and a primary cause of hypoprolificacy in boars (boars that produce a lower number of offspring). They cause significant economic losses due to reduction in litter sizes and many countries have set up screening programs to remove RT affected pigs from the populations.

The current standard method for screening is standard banded karyotyping, but this is often inaccurate, requires a specialist, is subjective, and limited for detecting smaller (cryptic) RTs. A potential solution to this problem is a novel device created in the Griffin Lab at the University of Kent. This multiprobe device does not require expertise nor advanced knowledge of the domestic pig karyotype and is able to detect cryptic RTs. Because of its superior accuracy and ease of use, this technology has the potential to replace standard karyotyping as the predominant screening method for RTs. The major pitfall to date is the Economic Consequences RTs in Pig Breeding and Benefits of Multiprobe Nicole Lewis 11 relatively expensive cost of the screening, which has kept it from being widely adopted.

The main aims of this thesis were to give an empirical assessment of the impact of RTs in modern pig breeding and thence calculate the relative benefit (if any) of the novel multiprobe device compared to karyotyping for RT detection. Specifically, this thesis provides an extensive overview of the structure of the pig industry, gives insight into how an RT can affect different businesses and calculates potential losses incurred from an RT being allowed to persist in a herd. In so doing, the relative benefits of the multiprobe were assessed. The key findings were that, in a "farrow to wean" hypothetical scenario, with one RT boar having performed 335 matings, the costs of an RT were ~£75,921 to ~£100,424. In a "farrow to finish" scenario with the same number of matings, the general costs of an RT were ~£240,719. In a dam line grandparental (GP) boar with a hypothetical RT scenario, in general the cost of an RT is £1,340,686. In a dam line great grandparental (GGP) boar with a hypothetical RT scenario, the cost of an RT is approximately £130,183,215. The study also examined two real world cases where an RT was missed by karyotyping but detected by the FISH multiprobe device, in each case, if FISH multiprobe device had been used initially, it would have saved the companies £17,430.91 and £738,085.16 respectively. The thesis concludes that the costs of mass screening of single sire breeding boars by the FISH multiprobe device far outweighs the potential risks of an RT being undetected (either by using karyotyping, or by not screening at all) and that the multiprobe approach is far more cost-effective in the long run than standard karyotyping.