Challenges and opportunities in genetic improvement of local livestock breeds

Abstract

Sufficient genetic variation in livestock populations is necessary both for adaptation to future changes in climate and consumer demand, and for continual genetic improvement of economically important traits. Unfortunately, the current trend is for reduced genetic variation, both within and across breeds. The latter occurs primarily through the loss of small, local breeds. Inferior production is a key driver for loss of small breeds, as they are replaced by high-output international transboundary breeds. Selection to improve productivity of small local breeds is therefore critical for their long term survival. The objective of this paper is to review the technology options available for the genetic improvement of small local breeds and discuss their feasibility. Most technologies have been developed for the high-input breeds and consequently are more favorably applied in that context. Nevertheless, their application in local breeds is not precluded and can yield significant benefits, especially when multiple technologies are applied in close collaboration with farmers and breeders. Breeding strategies that require cooperation and centralized decision-making, such as optimal contribution selection, may in fact be more easily implemented in small breeds.

Keywords: genetic diversity; genomics; local breeds; phenotyping; selection.

FIGURE 1

Distribution of world cattle and sheep breeds according to the number of breeding females (data source DAD-IS: www.dad.fao.org, accessed on January 13, 2015): <1,000, 1,000–2,000, >2,000.

FIGURE 2

Annual genetic gain (ΔG) (standard deviation units) with optimum contribution selection (OCS) and truncation selection (TS) in populations from 500 to 6,000 females (FF) with inbreeding control (Gandini et al., 2014b).