Ligilactobacillus salivarius MP100 as an Alternative to Metaphylactic Antimicrobials in Swine: The Impact on Production Parameters and Meat Composition

Abstract

The metaphylactic use of antimicrobials in swine farms contributes to the emergence of antibiotic-resistant bacteria, which constitutes a major challenge for public health. Alternative strategies are required to eradicate their routine use. In a previous study, metaphylactic antimicrobials were replaced by the administration of Ligilactobacillus salivarius MP100 to sows and piglets for two years. This practice positively modified the fecal microbiota and metabolic profiles in the farm. In this work, the farm dataset was used to compare the productivity-related parameters between a 2-year period of routine metaphylactic antibiotherapy and the first 2 years of a replacement with the probiotic strain. The probiotic period improved these productivity-related parameters, from litter size to growth performance. In addition, samples of Longissimus lumborum, including skin and subcutaneous fat, were obtained from the animals ingesting the probiotic strain and controls (metaphylactic antibiotherapy) and analyzed for their pH, water holding capacity, composition, and metabolic profiling. The probiotic intake did not negatively affect the meat composition and was associated with an increase in inosine concentration and a slight tendency for increasing the intramuscular fat content. These factors are considered as biomarkers of meat quality. In conclusion, the substitution of metaphylactic antimicrobials with the administration of the probiotic strain was associated with beneficial productivity and meat quality outcomes.

Keywords: Ligilactobacillus salivarius; growth performance; meat quality; probiotics; swine.

Figure 1

Comparison of fertility rates (% of inseminated sows that gave birth to a live litter) (a), and average litter size and final number of piglets weaned per sow (b) between the two periods analyzed in this study (metaphylactic antimicrobial period versus probiotic period). Significant differences are indicated as * (p < 0.05) or ** (p < 0.01).

Figure 2

Comparison of mortality rates (%) in the nursing, transition, and fattening stages, and overall mortality rates from birth to sale between the two periods analyzed in this study (metaphylactic antimicrobial period versus probiotic period). Significant differences are indicated as ** (p < 0.01).

Figure 3

Comparison of average number of days from birth to slaughter (a), and average daily weight gain (b) between the two periods analyzed in this study (metaphylactic antimicrobial period versus probiotic period). Significant differences are indicated as *** (p < 0.001).

Figure 4

Representative ¹H NMR spectra of an LL exudate analyzed in this study. Peak assignments are given in Table S1 (Supplementary Materials). The box shows a region (inosine signals) in which differences between the samples of the probiotic and control groups were detected.