Project Number: 6612-31000-014-01
Project Type: Reimbursable

Start Date: Jun 29, 2007
End Date: May 14, 2009

Objective:
1) Identify genes and pathways that are differentially expressed between pigs that differ in residual feed intake and that respond to a restriction in feed intake ; 2) Identify genes and pathways that respond to intra-cerebroventricular injection of agonists and antagonists of melanocortin 4 receptor in pigs with alternate melanocortin 4 receptor genotypes; 3) Identify genes and pathways differentially expressed between pigs that differ in residual feed intake and melanocortin 4 receptor genotype; 4) Integrate expression profile results from objectives 1-3 with data from other species to identify genes and pathways that control feed intake and feed efficiency.

Approach:
Feed is the major variable cost in pork production. Improving traits related to feed intake and feed efficiency, can be overcome if the genetic mechanisms that control feed intake and feed efficiency were known. Microarray technology and bioinformatics will be used to identify appetite regulating genes in brain, pituitary, stomach, liver, adipose tissue, muscle and adrenal glands collected from pigs selected for quantitative differences in residual feed intake, that have genetic differences at the melanocortin 4 receptor gene. This information will be useful in identifying gene targets for genetic improvement and provide data for comparative approaches. Identifying genes and pathways that control feed intake and feed efficiency in pigs will enable integration of genomics into conventional breeding programs.