107 The effect of water acidifiers on growth performance and general health of commercially housed weaned pigs

Abstract

The study compared the efficacy of supplementing the drinking water with acidifiers on growth performance and general health of commercially housed weaned pigs. The study design was a randomized complete block using 1152 mixed-sex weaned pigs (~21 days old; 6.99 ± 0.31 kg BW) assigned to three treatments (384 piglets/ treatment) with 24 replicate pens (16 pigs/pen) per treatment. The treatments were: regular (non-supplemented) drinking water (Control) or drinking water supplemented with either acidifier blend A (composed largely of formic acid, propionic acid, and acetic acid), or blend B (composed largely of formic acid and lactic acid) administered for the first 21 days of the study. All pigs were fed a common 3-phase commercial feed (P1, days 1-10; P2, days 11-21; P3, days 21-42) containing nutritional levels of Zn (150 ppm ZnO). Body weight (BW) and feed disappearance were recorded weekly to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR). Body condition scoring and diarrhea frequency and severity were measured weekly for the first four weeks, with daily record of water disappearance. Individual end weights were categorized into light, average, and heavy (i.e., < 1, ± 1, and >1 standard deviation of the mean weight, respectively). Data were analyzed using PROC GLMMIX of SAS with appropriate models for the different data distributions; pen served as the experimental unit. The overall herd mortality was 0.61%, with a culling rate of 1.74%, and 1.13% of pigs receiving medical treatment for leg-related problems. Treatment did not significantly impact diarrhea incidence or severity, body condition score, or survival rate at the end of the study (P >0.10). During the water acidification period (d0-21), pigs receiving blend A had a greater ADG (P< 0.05; +15 g/d) and heavier BW (P< 0.05; +300 g) than those on blend B or Control. Additionally, FCR was lower (P< 0.05; -0.04 g/g) for blend A pigs than for Control, and water disappearance was greater for both blends A and B than Control (P< 0.05; +0.741 L/pig/d). For the entire nursery period (d0-42), pigs offered blend A had a greater ADG (P< 0.05; +9 g/d) and a heavier end weight (P< 0.05; +400 g) than those offered blend B and Control. Blend A resulted in fewer pigs with light BW (P=0.026; -6%) and tended to have more pigs with an average body (P=0.09; +6%) than Control. Finally, water disappearance from d0-41 was greater for pigs offered blends A and B than Control (P< 0.05; +0.814 L/pig/d). In conclusion, different formulations of water acidifiers differentially affect weaned pig’s growth. A combination of formic, propionic, and acetic acids resulted in heavier pigs than a combination of formic and lactic acids.