Abstract The objective of this study was to investigate the effects of monobutyrin, monovalerin, or their combinations on the apparent and standardized ileal digestibility (AID and SID) of amino acids in weanling pigs 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 treatments (n = 16) in a randomized complete block design with group and sex as blocks. The treatments included a negative control (NC) without ETEC infection, a positive control 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 low dose combination (0.05% monobutyrin and 0.05% monovalerin), and a high dose combination (0.075% monobutyrin and 0.075% monovalerin), respectively. Titanium dioxide was added to all dietary treatments as an indigestible marker. The experiment lasted for 28 days, including 7 days of adaptation and 21 days of post inoculation (PI). After the adaptation, all piglets except those in the NC group were orally inoculated with a 3 mL dose containing an equal amount of 5 × 109 CFU F4 and 5 × 109 CFU F18 ETEC for three consecutive days. Ileal digesta (n = 10) were collected on d 21 PI to calculate the AID of amino acids. The SID values were calculated by correcting the AID with basal endogenous losses as described in Almeida et al. (2013). Data were analyzed by ANOVA using SAS with a randomized complete block design and pig as the experimental unit. Pigs supplemented with high dose combination of monobutyrin and monovalerin had the highest (P 0.01) SID of Lys among all treatments. Pigs supplemented with 0.10% and 0.15% monobutyrin, 0.10% monovalerin, low dose and high dose combination had similar or greater (P 0.05) SID of Arg, His, Glu, Ile, Leu, Phe, Ser, Tyr, and Val compared with pigs in carbadox and NC groups. Pigs in carbadox group and high dose combination of monobutyrin and monovalerin group had significantly higher (P 0.05) SID of dispensable and indispensable amino acids compared with pigs in 0.10% sodium butyrate and 0.15% monovalerin groups. Pigs in positive control, 0.10% sodium butyrate, and 0.15% monovalerin groups had lower (P 0.05) total SID of amino acids compared with pigs in carbadox and high dose combination of monobutyrin and monovalerin groups. In conclusion, dietary supplementation of monobutyrin, low dose monovalerin, or their combination enhanced the ileal digestibility of amino acids in weaning pigs infected with ETEC F4 and F18.
Sun et al. (Wed,) studied this question.