Comparison of Grain Sources (Barley, White Corn, and Yellow Corn) for Swine Diets and Their Effects on Meat Quality and Production Traits
Iowa State University Animal Industry Report 2004. Efficient pork production is a necessity for an economically viable swine industry. Number two yellow corn is considered the primary energy source for swine diets in the Midwest. Despite the low protein content, corn is considered one of the most economical feed stuffs available to the swine production system. Barley is a high fiber that has approximately 89% of the energy content of corn. While barley contains a higher protein and amino acid level than corn, animal performance is expected to be depressed due to the high fiber content. Because barley lacks the carotene content that yellow corn possesses, it has been hypothesized that barley-fed pigs will yield higher meat and fat quality that is desired by export markets. White corn was used in this trial to determine its contribution to meat quality and growth traits. An experiment was conducted to evaluate the effect of energy source on performance and carcass traits of pigs. Diet treatments (primary energy source) were: 1) yellow corn, 2) white corn, 3) 1/3 yellow corn, 2/3 white corn, 4) 2/3 yellow corn, 1/3 white corn, 5) barley. Pigs completing the trial were from two sires lines, Duroc (n=500) and Hamp x Duroc (n=499), that were mated to PIC 1055 females. Pigs were randomly allocated to pens based on genetic type and gender using a 2 x 2 x 5 factorial arrangement with two genetic types, two sexes (barrows and gilts) and five treatments Animals fed these diets differing in energy source did not express a difference in average daily gain, average daily feed intake, feed-to-gain ratio, backfat depth or percent fat free lean. However, barley-fed pigs did have a smaller (p < .05) loin muscle area than pigs fed corn-based diets. Diet did not have an effect on sensory panel traits for tenderness or chewiness and limited differences were observed for juiciness, flavor, and off-flavor. Percentage loin purge, and cooking loss did not differ among diets fed to the pigs with minimal difference noted for color values. Pigs fed barley diets did have lower iodine value content within the subcutaneous fat indicating that the fat is of firmer quality. Results of this trial suggest that barley does not have an advantage in meat quality traits when compared to traditional corn-based diets. Barley does however have a significant impact on the hardness of pork fat, but does not have a significant effect on subjective color values.