In Exp. 1, a total of 40 barrows and 40 gilts were distributed according to initial body weight and fed 0, 1, 2, 3, or 4% RBC. Two barrows and two gilts per pen were randomly selected and slaughtered for collection of carcass measurements. Experiment 2 was similar to Exp. 1, except 0, 1, or 2% RBC were added. Each dietary treatment had 4 replicates per sex with 4 pigs per pen. One barrow and one gilt per treatment replicate were randomly selected and slaughtered for collection of carcass traits and viscera weights. Experiment 3 was similar to Exp. 2 except only barrows were used. Each dietary treatment had 4 replicates with 3 pigs per pen, and all pigs were slaughtered for collection of carcass traits and viscera weights.
In Exp. 1, final BW, ADG, and G:F were decreased linearly (P < 0.01 to 0.10) as RBC addition increased, but ADFI was not affected. With increased RBC addition, average backfat increased (P < 0.09) and fat free lean decreased (P< 0.04). There was a quadratic effect (P < 0.04) on dressing percentage (DP); the 2% RBC addition increased DP, but the 3 and 4% additions decreased DP. In Exp. 2, there was a quadratic effect (P < 0.07) of RBC addition on average backfat; the 1% RBC addition decreased backfat, but the 2% addition returned backfat to the level of the control pigs. There was no effect (P > 0.10) on any other response variable. In Exp. 3, with increased RBC addition, average backfat linearly decreased (P < 0.04) and large intestine percentage increased (P < 0.09). There was no effect of RBC addition (P > 0.10) on any other response variable.
It is concluded that feeding 3 or 4% red blood cells decreases growth performance of finishing pigs. However, feeding 1 or 2% red blood cells to finishing pigs had no detrimental effects on growth performance and increased DP in one experiment.
ED Frugé, TD Bidner, and LL Southern. 2009. Journal of Animal Science. 87:2853–2859.