144 Evaluating the effect of different doses of an organic acid and monoglyceride blend (Furst Strike) on nursery and finisher growth performance parameters

The increased antibiotic resistance to enteric pathogens such as Escherichia coli has led to a need for nutritionally supported gut health. We quantified the wean-to-market impact of poor enteric health in nursery pigs nutritionally supplemented with or without a blend of organic acids and esterified medium-chain fatty acids (Furst Strike, FS). Our objective was to investigate the optimal inclusion rate of FS in nursery diets to maximize lifetime growth performance using dose titration methodology. A total of 1,152 weaned pigs (6.2 ±0.14 kg) were blocked by parity and individual body weight and assigned to 1 of 4 dietary treatments: 1) Control, 2) Control + 2.5 g/kg FS, 3) Control + 5.0 g/kg FS, 4) Control + 7.5 g/kg FS. Nursery (N) diets were fed in three phases and finishing (F) diets in four phases: N1 (d 0-7), N2 (d 7-21), N3 (d 21-42), F1 (23-68 kg), F2 (68-91 kg), F3 (91-110 kg), and F4 (110-136 kg). FS was included only in N1 and N2. Pen weights were recorded on d 0, 7, 21, 42, 98, and 147, with individual weights on d 0, 42, 98, and 147. Pen ADG, ADFI, and Gain:Feed were calculated for each phase and overall. Morbidity, mortality, and daily injectable treatments were tracked. Data were analyzed in R using linear mixed models with Treatment as a fixed effect and fill as a random effect for nursery data. For finishing data, Nursery Treatment was a fixed effect with Initial BW as a covariate, except for Initial BW. Individual growth data were analyzed using linear models with Nursery Treatment as a fixed effect. Regression models assessed linear and quadratic trends across treatments. During N2, the population tested positive by culture and PCR for F18 enterotoxigenic Escherichia coli. Increased scouring was reported in all pens. Pigs fed FS during N1 had increased feed intake by 19% compared to control (Treatment, P=0.003) and reduced total removals in N2 from 3.2% to 1.06% regardless of inclusion level (Linear, P=0.030). Feeding 5.0 g/kg FS tended to reduce injectable treatments by 38% during N2 (Treatment, P=0.056). A linear increase in ADFI from F1-F3 was observed in pigs fed FS from 2.44 to 2.52 kg (Linear, P=0.042) driven by a 5% increase in F2 ADFI (Treatment, P=0.030, Linear P=0.005). Additionally, pigs fed FS experienced a 4% increase in overall finishing ADFI (Treatment, P=0.093; Linear, P=0.009). Feeding 5.0 g/kg FS in N1 and N2 tended to increase marketed body weight by 3.5 kg (Treatment, P=0.087) and improved lifetime ADG by 2.2% (Treatment, P=0.006). The 7.5 g/kg FS inclusion was too high based quadratic responses not improving performance. In conclusion, 5.0 g/kg FS supported improved wean-market performance in pigs experiencing early-life enteric health burdens.