Comparing the Effects of Butyric Acid Source and Level on Growth Performance of Nursery Pigs

A total of 400 nursery pigs(PIC 19×1050 or PIC 3×C 29 initially 6.2 ± 0.01 kg) were used to compare the effects of increasing levels of two encapsulated butyric acid sources on growth performance of nursery pigs. Dietary treatments were arranged as a 2 × 2 + 1 factorial with main effects of butyric acid source (ButiPEARL vs. ButiPEARLZ; Kemin Industries, Des Moines, IA) and acid source level (low (0.05 or 0.07%) vs. high (0.10 or 0.14%), for ButiPEARL or ButiPEARLZ, respectively) plus a control diet without butyric acid. The addition of butyric acid was established such that the same amount of butyric acid was contributed from each source for the low or high levels, respectively. Experimental diets were fed in 3 phases from d 0 to 7, 7 to 21, and 21 to 42. Pens of pigs were balanced by initial BW and randomly allotted to treatments, with 8 pens/treatment. From d 0 to 7, a source × level interaction (P<0.05) was observed for ADG, ADFI, and G:F with pigs fed diets containing ButiPEARL having improved performance at the low inclusion, with those fed the high level not different from the control. However, pigs fed ButiPEARLZ had similar performance to the control regardless of level. In Phase 2 (d 7 to 21), ADG and ADFI were not influenced by butyric acid source or level, but an interaction (P=0.002) was observed for G:F as pigs fed ButiPEARL had poorer G:F as level increased; whereas pigs fed increasing ButiPEARLZ had improved G:F. For Phase 3 (d 21 to 42), increasing either butyric acid source tended (P=0.060) to decrease ADG. Overall (d 0 to 42), butyric acid source or level did not affect ADG, ADFI or G: F. In conclusion, this study showed that pigs fed low ButiPEARL in Phase 1 (d 0 to 7) had improved growth performance compared to other treatments with only minor treatment effects observed thereafter.

				ButiPEARL				ButiPEARLZ			P<
Item	Control		Low		High		Low		High	SEM	Source × level	Source	Level
d 0 to 71
ADG, g	108b		139a		107b		89b		109b	7.68	0.002	0.003	0.413
G:F, g/kg	767ab		833a		729b		687b		766ab	6.20	0.007	0.096	0.711
d 0 to 42
ADG, g	481		470		456		452		446	8.88	0.693	0.130	0.260
G:F, g/kg	719		712		709		717		707	5.90	0.633	0.796	0.267
1Source × level interaction (P<0.05)