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Effect of a Low Energy, High Fiber Diet Challenge on Yorkshire Pigs Selected for Residual Feed Intake
Purebred Yorkshire pigs from generations 8 and 9 (n=334) of the Iowa State residual feed intake (RFI) lines, selected for low and high RFI under a standard high energy and low fiber diet, were challenged with a low energy and high fiber diet. In two replicates, littermate gilts and barrows from each line were randomly split between diets and grown from ~40 to ~118 kg with individual feed intake recorded. Performance traits of average daily feed intake, average daily gain, gain to feed ratio, RFI, off-test ultrasound backfat and loin muscle area were evaluated. Results suggested that response to genetic selection for RFI under a high energy, low fiber diet may not translate into similar improvements in feed efficiency under a low energy, high fiber diet.
Keywords:
Residual feed intake
Yorkshire pigs
Feed efficiency