We analyzed LTβR mRNA expression in piglets from birth to weaning and compared the differential expression between Escherichia coli F18-resistant and sensitive populations to determine whether this gene could be used as a genetic marker for E. coli F18 resistance. Sutai piglets of different age groups (8, 18, 30, and 35 days; N = 4 each) and piglets demonstrating resistance/sensitivity to E. coli F18 were used. LTβR expression levels were determined by real-time PCR.
Excess Leu reduces the availability of Ile and Val in pigs likely by reducing absorption of the latter amino acids (AA). Twenty-four crossbred pigs were used to evaluate the effect of excess Leu alone or with surplus Ile and Val on the expression of cationic (b0,+AT and CAT1) and neutral (B0AT1) AA transporters in the small intestine, liver, and skeletal muscle. Dietary treatments included: 1) basal diet; 2) basal plus 0.43% L-Leu (excess Leu); 3) basal plus 0.43% Leu, 0.20% L-Ile, and 0.25% L-Val (excess Leu, Ile, and Val).