Effect of Dietary Sugarcane Bagasse on Reproductive Performance, Constipation, and Gut Microbiota of Gestational Sows

Abstract

This experiment aimed to evaluate the effects of using sugarcane bagasse (SB) as a substitute for soybean hulls and wheat bran in the diet of pregnant sows on their reproductive performance and gut microbiota. A total of seventy-two primiparous sows were randomly divided into four treatment groups, with eighteen replicates of one sow each. The sows were fed a basal diet supplemented with 0% (CON), 5%, 10%, and 15% SB to replace soybean hulls from day 57 of gestation until the day of the end of the gestation period. The results showed that SB contains higher levels of crude fiber (42.1%) and neutral detergent fiber (81.3%) than soybean hulls, and it also exhibited the highest volumetric expansion when soaked in water (50 g expanding to 389.8 mL) compared to the other six materials we tested (vegetable scraps, soybean hulls, wheat bran, rice bran meal, rice bran, and corn DDGS). Compared with the CON, 5% SB significantly increased the litter birth weight of piglets. Meanwhile, 10% and 15% SB significantly increased the rates of constipation and reduced the contents of isobutyric acid and isovaleric acid in feces. Furthermore, 10% and 15% SB significantly disturbed gut microbial diversity with increasing Streptococcus and decreasing Prevotellaceae_NK3B31-group and Christensenellaceae_R-7-group genera in feces. Interestingly, Streptococcus had a significant negative correlation with isobutyric acid, isovaleric acid, and fecal score, while Prevotellaceae_NK3B31-group and Christensenellaceae_R-7-group had a positive correlation with them. In conclusion, our study indicates that 5% SB can be used as an equivalent substitute for soybean hulls to improve the reproductive performance of sows without affecting their gut microbiota.

Keywords: gestation sow; gut microbiota; reproductive performance; short-chain fatty acids; sugarcane bagasse.

Figure 1

The weight (A) of seven different fiber ingredients at the volume of 100 mL. The swelling volume (B) of seven different fiber ingredients at the weight of 50 g. Image of seven different fiber ingredients after by absorbing water (C). DDGS, distillers’ dried grains with soluble.

Figure 2

Effect of SB on fecal score (A) and constipation rate (B) of sows. Data are presented as mean ±SD, n = 16. Labeled means in a row with different letters differ, p < 0.05. The different colors represent different treatment groups, in which red represents CON group, green represents 5%SB group, blue represents 10%SB group, and purple represents 15%SB group. CON, control group; SB, sugarcane bagasse group.

Figure 3

Effect of SB on short-chain fatty acids in the feces of sows. Data are presented as mean ± SD, n = 8. Labeled means in a row with different letters differ, p < 0.05. The different colors represent different treatment groups, in which red represents CON group, green represents 5%SB group, blue represents 10%SB group, and purple represents 15%SB group. CON, control group; SB, sugarcane bagasse group.

Figure 4

Composition and diversities of the fecal microbiota in sows. Relative abundance of the top 10 phyla (A) and top 20 genera (B) in the four groups. Differences in alpha diversities were calculated using the Chao1 index (C) and Shannon index (D), respectively. Principal coordinates analysis (PCoA) plots were generated using Bray–Curtis distances (E). n = 8. Labeled means with different superscript letters are significantly different, p < 0.05. CON, control group; SB, sugarcane bagasse group.

Figure 5

Differential enrichment of the bacterial taxa was identified using LEfSe with an LDA score > 3.0 (A). Relative abundance of five differentially enriched bacterial features (B). Spearman correlation between fecal score and short–chain fatty acid and the differentially expressed genus (C). n = 8. Labeled means with different superscript letters are significantly different, p < 0.05. Correlation coefficients and p–values were determined via Spearman’s rho correlation test. *, p < 0.05, **, p < 0.01. LDA, Linear discriminant analysis; LEfSe, LDA effect Size; CON, control group; SB, sugarcane bagasse group.