Dietary probiotics supplementation in weanling diets improve pig performance independently of the dietary lactose level used.

Probiotic supplementation and dietary lactose levels were recently evaluated for their potential to improve piglet performance during the first weeks after weaning. The objective of the present study was to assess the interactions between the lactose level and a probiotic on weanling piglet performance, nutrient digestibility, intestinal microbiota and fecal noxious gas emission. A 2 x 2 factorial arrangement was used in this study. A total of two hundred and forty 24-day-old weaned piglets were allotted to one of four dietary treatments: 1) a control diet, with no probiotic or lactose supplementation; 2) a low lactose level diet (100g/kg); 3) a higher lactose level diet (200 g/kg); and 4) a probiotic supplemented diet (0.5g/kg). Experimental diets were fed for 28 days.

No interaction was reported between lactose levels and probiotic supplementation on ADG, ADFI, F/G and coefficient of total tract apparent digestibility (CTTAD) of dry matter (DM), gross energy (GE) and crude protein (CP). Piglets fed with a probiotic supplemented diet showed an improved ADG and ADFI, whereas high lactose supplementation had no significant effect on ADG and ADFI. However, piglets offered diets containing 200 g lactose/kg had a significantly higher CTTAD for DM and GE compared with the lower dietary lactose level piglets. Furthermore, the CTTAD of DM was higher both in high lactose and probiotic supplemented diets. Regarding intestinal microbiota, E. coli presence in ileum and cecum was decreased in probiotic-supplemented treatments. The ileal colonization of Salmonella spp. was reduced either in probiotic-supplemented and high lactose level diets. No effects were observed on morphological parameters between dietary treatments. Fecal total organic carbon and ammonium emissions were lower in piglets offered high lactose level or probiotic-supplemented diets. Probiotic supplementation improved growth performance and DM digestibility, while high lactose supplementation only increased DM digestibility. Yet, both high-lactose and probiotic diets decreased the emission of total organic carbon and ammonium.