219 Effects of short chain fatty acids derivatives on diarrhea and growth performance of weanling pigs challenged with F4 and F18 Enterotoxigenic Escherichia coli.

Abstract The objective of this study was to investigate the effect of two organic short-chain fatty acid derivates, monobutyrin and monovalerin, on diarrhea and growth performance of weanling pigs experimentally infected with F4 and F18 enterotoxigenic Escherichia coli (ETEC). A total of 176 pigs (7.14 ± 1.12 kg, 88 gilts and 88 barrows, 21 to 24 days old) were housed individually and randomly allotted into 11 treatment groups (n = 16) in a randomized complete block design with litter, initial BW and sex as blocks. The treatments included a negative control (NC) without ETEC infection, a positive control (PC) with ETEC, and 9 additional groups supplemented with 50 mg/kg carbadox, 2,500 mg/kg zinc oxide (ZnO), 0.10% sodium butyrate, 0.10% or 0.15% monobutyrin, 0.10% or 0.15% monovalerin, a combination of 0.05% monobutyrin and 0.05% monovalerin, and a combination of 0.075% monobutyrin and 0.075% monovalerin, respectively. The experiment lasted for 28 days which included 7 days of adaptation period and 21 days of post-inoculation (PI). After the adaptation, all piglets except those in the NC group were orally inoculated with 3 mL dose containing an equal amount of 5 × 109 CFU F4 and 5 × 109 CFU F18 ETEC for three consecutive days. Body weight was measured on day -7 and day 0 before the ETEC inoculation and on day 5, 14, and 21 PI. Diarrhea score (DS; 1, normal, to 5, watery) was recorded twice daily and the frequency of diarrhea (DS ≥ 3 and DS ≥ 4) was calculated for the entire experimental period. Data were analyzed by ANOVA using PROC MIXED of SAS with a randomized complete block design using pig as experimental unit. Daily diarrhea score significantly increased on day 1 PI and remained high till day 5 PI, indicating the success of ETEC inoculation. Pigs in the PC had higher (P < 0.05) frequency (DS ≥ 3, 28.6%) and severity of diarrhea (DS ≥ 4, 15.0%) compared with pigs in the NC (9.0% and 3.3% respectively). Supplementation of high dose ZnO or carbadox resulted in the lowest frequency of diarrhea (DS ≥ 3 and DS ³ 4), followed by sodium butyrate, monobutyrin (0.10 and 0.15%), and 0.15% monovalerin, compared with the PC. The combination of low-dose monobutyrin and monovalerin also reduced the severity of diarrhea (P < 0.05) compared with the PC. Inclusion of ZnO, carbadox, 0.15% monobutyrin and the combination of low-dose monobutyrin and monovalerin yielded higher (P = 0.054) body weight on d 5 PI compared with the PC group. In conclusion, dietary supplementation of monobutyrin or monovalerin can reduce the severity of diarrhea and enhance the growth rate of weaning pigs infected with ETEC F4 and F18. diarrhea, short chain fatty acid derivatives, weaned pigs