Effects of corn particle size and diet form on finishing pig growth performance and carcass characteristics

Abstract Text: A total of 960 pigs (PIC TR4 × Fast Genetics York-AND × PIC Line 02; initially 34.3 kg BW) were used in a 101-d trial to determine the effect of corn particle size and diet form on finishing pig growth performance and carcass characteristics. There were 8 pens per treatment and 20 pigs per pen. Treatments were arranged in a 2 × 3 factorial with main effects of diet form and particle size. Diet forms were meal or pellet. Particle sizes were 650 µ, 350 µ, or an equal blend of the 650 µ and 350 µ ground corn. Diets were fed in 4 phases with the same corn-soybean meal–based diet containing 30% dried distillers grains with solubles (DDGS) (Phases 1 to 3) or 15% DDGS (Phase 4) used for all treatments. Overall (d 0 to 101), linear diet form × particle size interactions were observed (P<0.02) for ADFI and G:F due to ADFI decreasing and G:F increasing as particle size was reduced for pigs fed meal diets but not for pigs fed pelleted diets. Pigs fed pelleted diets had increased (P<0.001) ADG, G:F and HCW compared with pigs fed meal diets. As corn particle size decreased, ADG and ADFI decreased (linear, P<0.02). Carcass yield, backfat, and loin depth were not influenced (P>0.26) by particle size or diet form. In summary, pigs fed pelleted diets had improved growth performance compared with those fed meal diets, with the greatest improvement in G:F observed when diets contained the coarsest ground (650 µ) corn. Feed efficiency improved as corn particle size decreased for pigs fed meal diets but not for those fed pelleted diets.

Diet form:	Meal			Pellet
Particle size:	650 µ	50% 650 µ + 50% 350 µ	350 µ	650 µ	50% 650 µ + 50% 350 µ	350 µ	SEM
ADG, kg	0.90	0.89	0.86	0.94	0.93	0.92	0.010
ADFI, kg	2.41	2.37	2.26	2.35	2.37	2.35	0.030
G:F	0.372	0.375	0.382	0.399	0.392	0.391	0.003
HCW, kg	88.6	89.5	87.7	93.1	92.3	90.4	0.915
Yield, %	74.1	74.3	74.6	74.5	74.4	74.3	0.402
Backfat, mm	15.7	15.8	15.8	16.4	15.7	16.4	0.411
Loin depth, mm	66.6	65.5	66.1	66.3	67.2	65.3	1.037
Lean, %	55.6	55.2	55.3	55.2	55.9	55.1	0.326

Keywords: particle size, pig, pellets