Effects of Bacillus-based probiotics on growth performance, nutrient digestibility, and intestinal health of weaned pigs Running Title (within 10 words)Effects of dietary probiotics on weaned pig health

This experiment was performed to verify whether dietary heat-killed Lactobacillus rhamnosus (LR) improves growth performance and modulates immune responses of weaned pigs. Ninety-six weaned pigs [(Landrace x Yorkshire) x Duroc; 6.95 ± 0.25 kg BW; 28 d old] were randomly allocated to four treatments: 1) a basal diet without heat-killed LR (CON), 2) T1 (CON with 0.1% heat-killed LR), 3) T2 (CON with 0.2% heat-killed LR), and 4) T3 (CON with 0.4% heat-killed LR). Each treatment had six pens with four pigs (6 replicates per treatment) in a randomized completely block design. The heat-killed LR used in this study contained 1 × 10 9 FU/g of Lactobacillus rhamnosus in a commercial product. Pigs were fed each treatment for four weeks using a two-phase feeding program to measure growth performance and frequency of diarrhea. During the last week of this study, all diets contained 0.2% chromic oxide as an indigestible marker. Fecal sampling was performed through rectal palpation for the consecutive three days after the four adaptation days to measure apparent total tract digestibility (ATTD) of dry matter, crude protein, and gross energy (GE). Blood sampling was also performed on days 1, 3, 7, and 14 after weaning to measure immune responses such as serum tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), C-reactive protein (CRP), and cortisol. The heat-killed LR increased (p < 0.05) growth rate, feed efficiency, and ATTD of GE for overall experimental period compared with CON, but reduced (p < 0.05) post-weaning diarrhea. In addition, pigs fed diets contained heat-killed LR had lower concentrations of serum TNF-α (d 7; p < 0.05), TGF-β (d 7; p < 0.10), and cortisol (d 3 and 7; p < 0.05) than pigs fed CON. In conclusion, dietary heat-killed LR improved growth rate, modified immune responses of weaned pigs, and alleviated post-weaning diarrhea.

Dietary yeast cell wall products (YCW) are recognized as a feed additive due to multifunctional benefits by the biological response modulators. Thus, this study was conducted to verify a potential advantage of YCW for improving growth performance, nutrient digestibility, immune responses, and intestinal health and microbiota of weaned pigs. A total of 112 weaned pigs (7.99 ± 1.10 kg of body weight; 28 days old) were arbitrarily allocated to two experimental treatments with eight pigs (four barrows and four gilts) per pen and seven replicate pens per treatment in a completely randomized block design (block = BW and sex): (1) a basal diet based on corn and soybean meal (CON) and (2) CON + 0.05% YCW. The experimental period was for 4 weeks. There were no differences in final body weight, average daily feed intake, and gain-to-feed ratio between dietary treatments. In contrast, pigs fed YCW had higher average daily gain (p = 0.088) and apparent ileal digestibility of DM (p < 0.05) and energy (p = 0.052) and lower diarrhea frequency (p = 0.083) than those fed control diet (CON). Pigs fed YCW also had a higher (p < 0.05) ratio between villus height and crypt depth, villus width and area, and goblet cell counts in the duodenum and/or jejunum than those fed CON. Dietary YCW decreased (p < 0.05) serum TNF-α and IL–1β of weaned pigs on day 7 and 14, respectively, compared with CON. Furthermore, pigs fed YCW had higher (p < 0.05) ileal gene expression of claudin family, occludin, MUC1, INF-γ, and IL-6 and lower (p < 0.05) that of TNF-α than those fed CON. Lastly, there were no differences in the relative abundance of bacteria at the phylum level between CON and YCW. However, dietary YCW increased (p < 0.05) the relative abundance of genera Prevotella and Roseburia compared with CON. This study provided that dietary YCW improved growth rate, nutritional digestibility, and intestinal health and modified immune responses and intestinal microbiota of weaned pigs.

This study was conducted to evaluate effects of dietary multi-carbohydrases (MCS) in a lactating sow diet on productive performance and immune responses of sows and their piglets. A total of 12 sows (218.37 ± 5.5 kg BW; 2 parity) were randomly assigned to 2 dietary treatments: a diet based on corn-soybean meal (CON) and CON with 0.01% MCS. The MCS contained xylanase (2,700 units/g), β-glucanase (700 units/g), and cellulase (800 units/g). Sows were fed the dietary treatments for 28 days (weaning) after farrowing. Blood samples were collected from sows on d 0, 3, and 7 after farrowing and randomly selected 2 nursing piglets in each sow on d 3, 7, and 14 after birth. Measurements were productive performance of sows, frequency of diarrhea of piglets, and immune responses of sows and their piglets. Sows fed MCS had lower (p < 0.05) their body weight change than those fed CON. Piglets from sows fed MCS had higher (p < 0.05) average weight gain and body weight at weaning day and lower (p < 0.10) frequency of diarrhea than those from sows fed CON. Sows fed MCS had lower number of white blood cells (WBC) on d 3 (p < 0.05) and TGF-β1 on d 7 (p < 0.10) during lactation than those fed CON. Similarly, piglets from sows fed MCS had also lower (p < 0.05) number of WBC on d 3 and d 7 and TGF-β1 and C-reactive protein on d 7 during lactation than those from sows fed CON. In addition, piglets from sows fed MCS had higher (p < 0.10) immunoglobulin G and M on d 7 during lactation those from sows fed CON. In conclusion, addition of dietary MCS in the lactating sow diet based on corn and soybean meal improved productive performance of sows and their litters and modulated their immune responses.

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