The effect of dietary protein levels on reproduction performance and E. coli shedding in sows

Low protein levels in sows’ gestation diets have been associated with fetal development. Low dietary protein levels have also demonstrated to increase protein absorption efficiency when maintaining the levels of digestible essential amino acids and to decrease the available amino acids for microbial fermentation in the large intestine. The microbiota of the sow affects the intestinal colonization of the piglets. Moreover, an important production disease for piglets is weaning diarrhea, caused by enterotoxigenic Escherichia coli (E. coli). Therefore, we investigated the effect of two levels of crude protein in gestation diet and the effects on reproduction parameters, the abundance of E. coli in feces of the sow and piglets performance until weaning.
The hypothesis was tested with high and low protein levels in sow diets (12 (LP)vs 17% (HP) crude protein (CP)) during the last five weeks of gestation until farrowing. After farrowing, all sows received the same lactation diet (16% CP). From each sow, four faecal samples were taken over time: at 5 weeks before (before treatment), 1 week before (gestation stable), 4 days before (farrowing stable) and 2 weeks after farrowing. Fecal samples were diluted and cultivated on BIO-RAD RAPID'E.coli 2 Medium. Microbial colony-forming units (CFUs) were calculated and transformed with LOG. Statistical analysis was performed using RStudio with linear mixed-effect models (lme4 package) and pairwise comparison (emmeans package).
No treatment effect was found in weight gain/-loss before farrowing (LP 260.76kg±13.04, HP 249.86kg±10.96), back fat thickness (LP 16.76mm±1.09, HP 15.36mm±1.13) or litter size (17±0.8, HP 16.28±1.1). No difference was found for piglet weight at farrowing (LP 1.42kg±0.06, HP 1.35kg±0.42) or weaning (LP 7.2kg±0.26, HP 7.45kg±0.23). For E. coli counts (log), an average was found for LP 6.99±0.14 (se) and HP 7.08±0.14 (se), but no treatment differences were found. In conclusion, no effect on sow performance, or E. coli shedding were found. Future research will focus on nitrogen digestion in sows and microbiota in piglets.