Evaluation of a Phytogenic Blend on Nursery Pig Growth and Nutrient Digestibility

Two experiments were conducted to determine the effect of a phytogenic feed additive (PFA) on growth performance (exp. 1) and nutrient digestibility (exp. 2) in nursery pigs. Dietary treatments were: 1) basal diet [CON] and 2) basal + 0.015% PFA (Digestarom^®, BIOMIN Holding GmbH). Diets were corn-soybean meal based and formulated to contain 4.42 and 3.85 g SID lysine/MCal ME for phase 1 (d 0 – 14) and 2 (d 14 – 35), respectively. Diets were identical for exp. 1 and 2, and the phase 2 diet contained 0.4% titanium dioxide as indigestible marker. In exp. 1, pigs (n=16/trt, BW=7.52 ± 0.84 kg) were individually penned and fed ad libitum for 35 d. Body weight and feed disappearance were measured on d 14 and 35. In exp. 2, pigs (n=11/trt, BW=7.50 ± 1.04 kg) were fed ad libitum until d 21 before being placed in metabolic crates and fed three times of maintenance. Total feces and urine were collected from d 23 to 26. On d 28, pigs were euthanized and digesta were collected from the last 60 cm of distal ileum. In exp.1, for the 35-d period, no statistical significance was noted with PFA supplementation (CON vs. PFA, P≥0.223) on BW (18.69 vs. 19.87 kg), ADG (0.321 vs. 0.350 kg/d), ADFI (0.493 vs. 0.551 kg/d), and Gain:Feed (0.648 vs. 0.636 kg/kg). In exp. 2, supplementation of PFA did not significantly affect (CON vs. PFA, P≥0.590) apparent total tract digestibility (ATTD) of DM (81.0 vs. 80.5%), OM (83.7 vs. 83.3%), N (74.6 vs. 75.8%), and GE (78.3 vs. 77.8%) but tended to reduce ATTD of P (53.4 vs. 44.2, P=0.064). Supplementation of PFA tended to increase N intake (15.72 vs. 18.95 g/d, P=0.057) while significantly reduced urine N excretion (2.96 vs. 2.25 g/d, P=0.012) and increased N retention (8.78 vs. 12.06 g/d, P=0.041) but did not affect fecal N excretion (3.98 vs. 4.64 g/d, P=0.259). Supplementation of PFA numerically increased (CON vs. PFA, P ≥ 0.213) apparent ileal digestibility (AID) of Arg (76.3 vs. 83.1%), His (73.0 vs. 78.5), Ile (69.6 vs. 75.5), Leu (69.6 vs. 76.3), Lys (79.7 vs. 84.1), Met (78.0 vs. 82.6), Phe (71.0 vs. 76.5), Thr (58.8 vs. 58.8), Trp (73.5 vs. 75.0), and Val (68.7 vs. 72.2). Overall, the supplementation of PFA resulted in a greater retention of N in nursery pigs and numerical improvements in pig growth that can be associated with altered AID of AA.