Fermented calcium butyrate supplementation in post-peak laying hens improved ovarian function and tibia quality through the“gut-bone”axis

The compromised egg quality and leg abnormality during the end of the laying cycle(after 40 weeks)have been leading to poor animal welfare and substantial economic losses.Therefore,the effects of fermented calcium(Ca)butyrate,produced by fermentation by Clostridium butyricum,on production,eggshell quality,and tibial property of hens were explored.A total of 192 Hy-line brown laying hens at50-week-old were assigned to a basal diet or the basal diet with 300 mg/kg of the fermented Ca butyrate from 50 to 58 weeks of age.Each treatment had 6 replicates with 16 hens each.The diet supplemented with 300 mg/kg fermented Ca butyrate notably increased egg weight,ovarian follicle number,and eggshell strength(P=0.072)as compared to the basal diet,which were associated with cytokine secretion,toll-like receptor signaling pathways,and intestinal immunity based on the RNA-seq data from the granulosa.Dietary Ca butyrate inclusion decreased the expression of ileal tumor necrosis factor-alpha and serum pro-inflammatory cytokine concentration,as well as increased the content of serum immunoglobulin A when compared to the basal diet(both P<0.05).The birds that received fermented Ca butyrate diets exhibited higher villus height(P<0.05)and upregulated expression of tight junction proteins,whereas it did not alter the composition of cecal microbiota(P>0.05).In addition,the diet with fermented Ca butyrate reduced the number of osteoclasts in the proximal tibia and the level of C-terminal cross-linked telopeptide of type I collagen,a bone resorption marker(P<0.05),whereas it tended to increase the concentration of the procollagen type I N-terminal propeptide that reflects bone formation marker in serum.Moreover,the layers fed fermented Ca butyrate diets possessed higher(P<0.05)bone area and trabecular number of the proximal tibia,yield load,and ultimate load than those that consumed basal diets.Collectively,dietary fermented Ca butyrate supplementation in post-peak layer diets improved the ovarian function and tibia quality,which might be related to enhancing intestinal integrity and consequently decreasing inflammation mediated bone resorption.

Dietary lysozyme improves growth performance and intestinal barrier function of weaned piglets

Lysozyme(LZ)is a purely natural,nonpolluting and nonspecific immune factor,which has beneficial effects on the healthy development of animals.In this study,the influences of LZ on the growth performance and intestinal barrier of weaned piglets were studied.A total of 48 weaned piglets(Landrace×Yorkshire,22 d old)were randomly divided into a control group(basal diet)and a LZ group(0.1%LZ diet)for 19 d.The results showed that LZ could significantly improve the average daily gain(ADG,P<0.05)and average daily feed intake(ADFI,P<0.05).LZ also improved the intestinal morphology and significantly increased the expression of occludin in the jejunum(P<0.05).In addition,LZ down-regulated the expression of interleukin-1β(IL-1β,P<0.05)and tumor necrosis factor-a(TNF-a,P<0.05),and inhibited the expression of the genes in the nuclear factor-k-gene binding(NF-κB,P<0.05)signaling pathway.More importantly,the analysis of intestinal flora showed LZ increased the abundance of Firmicutes(P<0.05)and the ratio of Firmicutes to Bacteroidota(P=0.09)at the phylum level,and increased the abundance of Clostridium_sensu_stricto_1(P<0.05)and reduced the abundance of Olsenella and Prevotella(P<0.05)at the genus level.In short,this study proved that LZ could effectively improve the growth performance,relieve inflammation and improve the intestinal barrier function of weaned piglets.These findings provided an important theoretical basis for the application of LZ in pig production.