Growth and Performance of Finishing Pigs Fed Oat Screenings

Forty-five crossbred barrows (initial BW 73.1 ± 2.3 kg) were used to evaluate effects of feeding diets containing 20% oat screenings or 20% wheat middlings. Oat screenings are a high-fiber by-product of cleaning oats. Pigs were allotted to 15 partially-slatted pens (3.34 m²) and dietary treatments were randomly assigned to pens. Pigs were fed three dietary treatments in two phases for 8 weeks total. Dietary treatments were corn-soybean meal control, corn-soybean meal diet containing 20% wheat middlings, and corn-soybean meal diet containing 20% oat screenings. The control and 20% wheat middlings diets were formulated to be isocaloric and oat screenings replaced wheat middlings in the 20% oat screening diet. Pigs were weighed every 14 d and feed disappearance was recorded. At trial end, all pigs were scanned using digital ultrasound to measure back fat and loin muscle area. Data was analyzed as a completely randomized design with 5 replicates per treatment. Pens were considered the experimental units. Significance was declared at P ≤ 0.05. When differences were observed, means were compared using the Tukey-Kramer method (SAS Inst. Inc., Cary, NC). Growth and performance of pigs fed 20% wheat middlings was not different from pigs fed control diets (P > 0.10). Pigs fed diets containing 20% oat screenings had decreased ADG as compared to pigs fed the control or 20% wheat middlings diets (0.94 vs 1.13 vs 1.04 g/d; SEM 0.02; P < 0.01). Pigs fed the control or 20% wheat middlings diets had increased G:F as compared to pigs fed diets containing 20% oat screenings diets grew less efficiently (0.32 vs 0.30 vs 0.27 g/g; SEM = 0.01; P < 0.01). Average daily feed intake and back fat thickness was not different across treatments (P > 0.10) but loin muscle area of pigs fed 20% oat screenings diets were smaller than pigs fed the control or 20% wheat middlings diets (20.57 vs. 23.07 vs. 22.70 cm²; SEM = 0.42; P < 0.01). Estimated fat free lean, lean gain, and lean gain efficiency were not different across dietary treatments (P > 0.10). Based on diet composition and calculated analysis, the 20% oat screenings diets contained 4–5% less ME and 11–12% less SID Lysine compared to control or 20% wheat middlings diets. Because oat screenings contain 25% ADF compared to 6% ADF in wheat middlings the difference in NE of the two diets may be greater than estimated.