Selecting the hologenome to breed for an improved feed efficiency in pigs—A novel selection index

Most traits in animal breeding, including feed efficiency traits in pigs, are affected by many genes with small effect and have a moderately high heritability between 0.1 and 0.5, which enables efficient selection. Since the microbiota composition in the gastrointestinal tract is also partly heritable and was shown to have a substantial effect on feed efficiency, the host genes affect the phenotype not only directly by altering metabolic pathways, but also indirectly by changing the microbiota composition. The effect of the microbiota composition on the breeding value of an animal is the conditional expectation of its breeding value, given the vector with microbiota frequencies, that is The breeding value of an animal can therefore be decomposed into a heritable contribution that arises from an altered microbiota composition and a heritable contribution that arises from altered metabolic pathways within the animal, so Instead of selecting for breeding value , an index comprising the two components and with appropriate weights, that is , can be used. The present study shows how this breeding strategy can be applied in pig genomic selection breeding scheme for two feed efficiency traits and daily gain.     

Beiträge zu der Jrage űber die mahrfcheinliche Zufunft des Sichenfchälwalb-Betriebs in Sűddeutfchland

Ohne Zusammenfassung     

Problemen Bij De Bestrijding Van De Brandzieketen Der Granen

Voordracht gehouden to Wageningen op 29 Sept. 1936 ter gelegenheid van de zevende Landbouwweek.     

Population and classification of intrapopulation units of helminths

The study of the population problems revealed that the population is an elementary evolution unit of a species with biparental way of reproduction. This is a general theoretical definition which the author elaborated in detail for the helminths. With regard to the complicated intraspecific structure of these parasites also the classification of intrapopulation helminth units is proposed.