Genetic association between individual feed intake during performance testand reproductions traits in pigs

The present study deals with the estimation of genetic correlations between performance test traits measured in boars and reproduction traits of their offspring (sibs) of two purebred lines. Performance traits were individual feed intake (FI) recorded by electronic feeder, feed conversion ratio (FCR ), average daily gain (ADG) and backfat thickness (BF). Reproduction traits were number of total piglets born (NBT) and born alive (NBA). Data of 4869 young boars, performance tested between April 1992 and May 1997 and data o f 9710 primiparous sows, farrowed between June 1994 to November 1998, were observed. Heritabilities of performance traits recorded on station were in line 03 (line 04) h(2) = 0.24 (0.33), 0.33 (0.33), 0.23 (0.32) and 0.47 (0. 53) for Fl, ADG, FCR and BF, respectively. Heritabilities of reproduction t raits such as NET, NEA were in line 03 (line 04) h(2) = 0.05 (0.08) and 0.0 5 (0.06), respectively. Genetic correlation between individual feed intake and reproduction traits ranged between r(g) = 0.12 and 0.27. Undesirable ge netic correlations were found between reproduction traits and feed efficien cy (r(g) = 0.13 to 0.44), backfat thickness (r(g) = 0.07 to 0.25) and partl y average daily gain (r(g) = -0.10 to 0.09). Line 04 showed lowest magnitud e of feed intake and highest genetic antagonism between production and repr oduction traits. It is suggested that feed intake capacity is a limiting fa ctor for reproduction in line 04 and genetic antagonism between production and reproduction traits increases with reduction in feed intake.