title: Effect of incremental levels of red blood cells on growth performance and carcass traits of finishing pigs.
abstract: Three experiments were conducted to determine the effect of incremental levels of red blood cells (RBC; 0 to 4%, Exp. 1; 0 to 2%, Exp. 2 and 3) on growth performance and carcass traits of finishing pigs. Dietary treatments were formulated to meet or exceed the nutrient requirements of barrows and gilts gaining 350 g of lean BW gain per day and were formulated to contain 0.52% apparent ileal digestible (AID) Lys for barrows and 0.59% AID Lys for gilts. In Exp. 1, barrows and gilts (2 replicates of barrows and 2 of gilts; 4 pigs per pen) were fed 0, 1, 2, 3, or 4% RBC. Initial BW (mean +/- SD) was 84.6 +/- 4.9 and 82.42 +/- 4.8 kg, and final BW was 118.7 +/- 6.5 and 120.0 +/- 9.6 kg for barrows and gilts, respectively. Two barrows and 2 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. Initial BW was 82.5 +/- 6.4 and 79.2 +/- 7.0 kg, and final BW was 125.5 +/- 6.2 and 119.8 +/- 8.8 kg for barrows and gilts, respectively. Each dietary treatment had 4 replicates per sex with 4 pigs per pen. One barrow and 1 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, and the initial and final BW were 86.0 +/- 5.7 and 133.4 +/- 8.4 kg, respectively. 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. The RBC addition had no effect (P > 0.10) on any remaining carcass measurements. 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. Our data indicate that feeding 3 or 4% RBC decreases growth performance of finishing pigs. However, feeding 1 or 2% RBC to finishing pigs had no detrimental effects on growth performance and increased DP in one experiment.
authors.affiliation: School of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803-4210, USA.
authors.forename: E D
authors.initials: ED
authors.lastname: Frugé
authors.forename: T D
authors.initials: TD
authors.lastname: Bidner
authors.forename: L L
authors.initials: LL
authors.lastname: Southern
mesh_terms: D000818:Animals; D001823:Body Composition / Q000502:physiology*; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D004912:Erythrocytes; D005260:Female; D008297:Male; D011897:Random Allocation; D013552:Swine / Q000254:growth & development / Q000502:physiology*