Dietary Supplementation of Choline and Potassium in Low Crude Protein Diets on Growth and Carcass Performance of Finishing Pigs

Research has shown that reduced SBM concentration in finishing swine fed low CP diets may be the reason reduced growth performance is sometimes observed. By reducing the amount of SBM in the diet, there is a reduction of dietary choline and potassium, among other nutrients. Two experiments were conducted to determine the effects of added choline or potassium in low CP diets in finishing pigs. In Exp. 1, 284 pigs (DNA 600×241, initially 112.2 kg BW) were used in a 26-d trial. Pens of 7 or 8 pigs were allotted by BW and randomly assigned to 1 of 4 dietary treatments in a RCBD with 9 replications per treatment. Treatments included a 12% CP, positive control diet with 10.6% SBM, a 10% CP; negative control (NC) diet with 4.0% SBM; NC with added choline (0.03%); or NC with added potassium (0.24%), such that the added choline or potassium matched the amount that is provided in the 12% CP diet. There was no evidence for differences in ADG (0.84, 0.82, 0.82, and 0.82 kg) or ADFI (2.83, 2.93, 2.97, and 2.93 g); however, there was a marginal improvement (P=0.085) in G:F (0.298, 0.279, 0.274, and 0.279) for pigs fed the positive control diet with 12% CP compared with the mean of pigs fed the diets with 10% CP. There was no evidence for differences in HCW (101.0, 100.7, 99.3, and 99.9 kg), yield (74.4, 74,9, 74.1, and 74.3%) or other carcass traits. In Exp. 2, 254 pigs (DNA 600×241, initially 110.5 kg BW) were used in a 19-d trial. Pens of 7 or 8 pigs were allotted by BW and randomly assigned to 1 of 4 dietary treatments in a RCBD with 8 replications per treatment. Experimental treatments were arranged in a 2 × 2 factorial with main effects of CP (12% or 10%) and added choline (0 or 1,814 mg/kg). Pigs fed diets with 12% CP had marginally increased (P=0.076) ADG (0.67 vs 0.62 kg/d) compared with pigs fed diets with 10% CP which resulted in a heavier (P=0.036) final BW (123.2 vs 122.2 kg). Pigs fed the diets with 12% CP also had improved (P=0.020) G:F (0.264 vs 0.245) compared with pigs fed the 10% CP diets. Addition of choline did not influence performance. In summary, supplementing diets with choline or potassium did not influence growth performance or carcass characteristics of pigs fed low CP diets.

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