Effects of Mulberry Branch and Leaves Silage on Microbial Community, Rumen Fermentation Characteristics, and Milk Yield in Lactating Dairy Cows

The effect of Phyllanthus emblica (Amla) fruit supplementation on the rumen microbiota and its correlation with rumen fermentation in dairy cows

Introduction

Medicinal plants, rich in phytochemicals like phenolic acids, flavonoids, and tannins, offer potential benefits in enhancing productivity, quality, and animal health. Amla fruit (Phyllanthus emblica) is one such plant with promising attributes. This study aimed to investigate the impact of fresh Amla fruit (FAF) supplementation on ruminal microbial composition and its correlation with rumen fermentation in lactating dairy cows.

Methods

The study employed a repeated crossover design involving eight ruminally cannulated mid-lactation Holstein dairy cows. Animals received varying levels of fresh Amla fruit supplementation (0, 200, 400, and 600 g/d).

Results

When 400 g/d of FAF was added to the diet, there was a significant increase in the relative abundance of Firmicutes (p = 0.02). However, at 200 g/d, the relative abundance of ruminal Bacteroidota was higher than the 0 and 400 g/d FAF supplementation (p < 0.01). LEfSe analysis identified distinct taxa, such as Clostridia vadinBB60 in the 200 g/d group, Oscillospiraceae in the 400 g/d group, and Elusimicrobium in the 600 g/d group. Notably, the random forest species abundance statistics identified Oscillospiraceae V9D2013 as a biomarker related to milk yield. Oscillospiraceae, Bacilli RF39, norank_f Prevotellaceae, and Bifidobacterium were positively correlated with ruminal total VFA and molar proportion of propionate, while Rikenellaceae RC9 gut group and Clostridia vadinBB60 were negatively correlated.

Discussion

FAF supplementation affects the abundance of beneficial microbes in a dose-dependent manner, which can improve milk yield, efficiency, rumen health, desirable fatty acids, and animal health.

Mulberry branch fiber improved lipid metabolism and egg yolk fatty acid composition of laying hens via the enterohepatic axis

BACKGROUND

The utilization of mulberry branch fiber (MF), the largest by-product of the sericulture industry, is an important issue. Supplementation with MF as a dietary fiber for poultry may serve as a useful application. However, little is known about the effects of MF on liver lipid metabolism and egg yolk fatty acid composition of laying hens and their underlying mechanisms. In this study, we performed a multi-omics investigation to explore the variations in liver lipid metabolism, egg yolk fatty acid composition, gut microbiota, and the associations among them induced by dietary MF in laying hens.

RESULTS

Dietary MF had no harmful effects on the laying performance or egg quality in laying hens. The enzyme activities associated with lipid metabolism in the liver were altered by the addition of 5% MF, resulting in reduced liver fat accumulation. Furthermore, dietary 5% MF induced the variation in the fatty acid profiles of egg yolk, and increased the polyunsaturated fatty acid (PUFA) content. We observed a significant reduction in the diversity of both gut bacteria and changes in their compositions after the addition of MF. Dietary MF significantly increased the abundance of genes involved in fatty acid biodegradation, and short-chain fatty acids biosynthesis in the gut microbiota of laying hens. The significant correlations were observed between the liver lipid metabolism enzyme activities of hepatic lipase, lipoprotein lipase, and total esterase with gut microbiota, including negative correlations with gut microbiota diversity, and multiple correlations with gut bacteria and viruses. Moreover, various correlations between the contents of PUFAs and monounsaturated fatty acids in egg yolk with the gut microbiota were obtained. Based on partial-least-squares path modeling integrated with the multi-omics datasets, we deduced the direct effects of liver enzyme activities and gut bacterial compositions on liver fat content and the roles of liver enzyme activities and gut bacterial diversity on egg yolk fatty acid composition.

CONCLUSIONS

The results indicate that dietary MF is beneficial to laying hens as it reduces the liver fat and improves egg yolk fatty acid composition through the enterohepatic axis. Video Abstract.

Protective Application of Morus and Its Extracts in Animal Production

Different components of the mulberry tree (fruits, leaves, twigs, and roots) are rich in active compounds, and have been reported to possess potent beneficial properties, including antioxidative, anti-inflammatory, antimicrobial, anticancer, anti-allergenic, antihypertensive, and neuroprotective. The mulberry and its extracts can effectively improve the growth performance and fitness of animals. They not only possess the properties of being safe and purely natural, but also they are not prone to drug resistance. According to the literature, the supplemental level of the mulberry and its extracts in animal diets varies with different species, physiological status, age, and the purpose of the addition. It has been observed that the mulberry and its extracts enhanced the growth performance, the quality of animal products (meat, egg, and milk), the antioxidant and the anti-inflammatory responses of animals. Furthermore, the mulberry and its extracts have antibacterial properties and can effectively moderate the relative abundance of the microbial populations in the rumen and intestines, thus improving the immunity function of animals and reducing the enteric methane (CH₄) production in ruminants. Furthermore, the mulberry and its extracts have the potential to depurate tissues of heavy metals. Collectively, this review summarizes the nutrients, active compounds, and biological functions of mulberry tree products, as well as the application in livestock production with an aim to provide a reference for the utilization of the mulberry and its extracts in animal production.

The gas production, ruminal fermentation parameters, and microbiota in response to Clostridium butyricum supplementation on in vitro varying with media pH levels

The aim of this study was to investigate the gas production (GP), dry matter disappearance (DMD), fermentation parameters, and rumen microbiota in response to Clostridium butyricum (CB) supplementation in batch culture using a high forage substrate. The doses of CB were supplemented at 0 (Control), 0.5 × 10⁶, 1 × 10⁶, and 2 × 10⁶  CFU/bottle, respectively, at either media pH 6.0 or pH 6.6. The 16S rRNA gene sequencing was used to detect the microbiota of fermentation culture in control and 1 × 10⁶  CFU/bottle after 24 h of incubation. The results showed that the GP (p < 0.001), DMD (p = 0.008), total volatile fatty acid (VFA) concentration (p < 0.001), acetate to propionate ratio (p < 0.001), and NH₃-N concentration (p < 0.001) were greater at media pH 6.6 than pH 6.0. Furthermore, the linearly increased DMD (pH 6.0, p = 0.002; pH 6.6, p < 0.001) and quadratically increased butyrate proportion (pH 6.0, p = 0.076; pH 6.6, p < 0.053) and NH₃-N concentration (pH 6.0, p = 0.003; pH 6.6, p = 0.014) were observed with increasing doses of CB. The Alpha diversity indexes of OTU number and Chao1 were higher (p = 0.045) at media pH 6.6 than pH 6.0, but they were not affected by CB supplementation. The PCoA analysis (unweighted uniFrac) demonstrated that the clustering of the bacterial microbiota of control and CB were distinctly separated from each other at media pH 6.0. At the phylum level, the abundance of Bacteroidota (p < 0.001) decreased, whereas that of Firmicutes (p = 0.026) increased when the media pH was elevated from 6.0 to 6.6. Supplementation of CB increased relative abundances of Rikenellaceae_RC9_gut_group (p = 0.002), Christensenellaceae_R-7_group (p < 0.001), and NK4A214_group (p = 0.002) at genus level. Interactions between media pH and CB addition were observed for bacteria at both phylum and genus levels. These results indicated that increasing the media pH level and CB supplementation increased in vitro rumen digestibility, and altered the ruminal fermentation pattern (by media pH) and microbiota.

Enteric Methane Emission, Rumen Fermentation and Microbial Profiles of Meat-Master Lambs Supplemented with Barley Fodder Sprouts

This study evaluated the effects of barley sprout on the ruminal fermentation characteristics, enteric methane emission and microbiome profiles of meat-master lambs. Twelve uncastrated lambs aged 3 months were used. They were randomly assigned to three dietary treatments: Eragrostis curvula hay as a control diet (T1), grass hay plus 25% barley sprouts (T2) and grass hay plus 50% barley sprouts (T3). Animals were fed the diet for 61 days, including 10 days of adaptation. Four animals per treatment were used to collect methane and rumen fluid. Methane emission was recorded for nine consecutive days, from day 52 to 60, using a hand-held laser detector. Rumen fluid was collected on day 61 using an esophageal stomach tube for volatile fatty acid and DNA sequencing. The sprout supplementation had significant (p < 0.05) effects on methane emission and ruminal fermentation. Significant effects on rumen fermentation were observed with regards to ammonia–nitrogen (NH3-N), acetic acid and a tendency (p < 0.0536) to increase propionic acid. Barley sprouts reduced methane gas emission, ammonia–nitrogen and the enhanced body weight of the animals. The bacteria Bacteroidota and Firmicutes were predominant among the identified phyla. In addition, there was a shift in the relative abundance of phylum among the treatments. The principal coordinate analysis showed a clear difference in microbiome among animals in T1 and those in T2 and T3. The sprout supplementation improves feed utilization efficiency by the animals. In conclusion, barley sprouts may be strategically used as a climate-smart feed resource for ruminants.

Effects of Different Concentrations of Lactobacillus plantarum and Bacillus licheniformis on Silage Quality, In Vitro Fermentation and Microbial Community of Hybrid Pennisetum

The purpose of the experiment was to study the effects of different concentrations of Lactobacillus plantarum (LP) and Bacillus licheniformis (BL) on the quality of hybrid Pennisetum (HP) silage. The experiment consisted of five treatment groups. The control group did not use additives, and the experimental groups were added with LP or BL of 1 × 105 cfu/g fresh weight (FW) and 1 × 107 cfu/g FW, respectively. The results showed that LP and BL could increase the in vitro fermentation gas production and reduce the ammonia nitrogen (AN) content in HP silage. Water-soluble carbohydrates (WSC), lactic acid (LA) content, and gas production in the LP group were positively correlated with LP addition, and acetic acid (AA) was negatively correlated with addition. The content of WSC and LA in the LP7 group was significantly higher than that in the control group (p < 0.05), and AA was lower than that in the control group (p > 0.05). Dry matter (DM), crude protein (CP), and gas production were negatively correlated with the addition of BL, while acid detergent fiber (ADF) content was positively correlated with the addition of BL. Furthermore, in the above indicators, the BL5 group reached a significant level with the control group (p < 0.05). The results of 16sRNA showed that the use of LP and BL could increase the relative abundance of Lactobacillus and decrease the relative abundance of Weissella in HP silage compared with the control group. In conclusion, LP and BL can significantly improve the quality of HP silage. The LP7 group and the BL5 group have the best silage effect. From the perspective of gas production in in vitro fermentation, the LP7 group had stronger fermentability and higher nutritional value.

Effects of Mulberry Leaves and Pennisetum Hybrid Mix-Silage on Fermentation Parameters and Bacterial Community

The silage quality and bacterial community of hybrid Pennisetum (P. hydridum × P. americanum) with or without 30% and 50% mulberry leaves for 3, 7, 14, and 30 days were investigated. Results showed that compared with the 100% hybrid Pennisetum group, more lactic acid (40.71 vs. 80.81 g/kg dry matter (DM)), acetic acid (10.99 vs. 31.84 g/kg DM), lactic acid bacteria (8.46 vs. 8.51 log10 cfu/g fresh matter), water-soluble carbohydrates (2.41 vs. 4.41 g/100 g DM), crude protein (4.97 vs. 10.84 g/100 g DM), and true protein (3.91 vs. 8.52 g/100 g DM) content as well as less neutral detergent fiber (67.30 vs. 47.26 g/100 g DM), acid detergent fiber (33.85 vs. 25.38 g/100 g DM), and yeast counts (4.78 vs. 2.39 log10 cfu/g fresh matter) and an appropriate pH (3.77 vs. 4.06) were found in silages added with 50% mulberry leaves at 30 days of ensiling. Moreover, the addition of mulberry leaves also influenced the relative abundance of the bacterial community. The relative abundance of Firmicutes increased and Proteobacteria decreased when mulberry leaves were added. Weissella and Lactobacillus abundance also increased. To sum up the above, mixing with 50% mulberry leaves yielded the greatest fermentation quality in this study. In conclusion, mixing with mulberry leaves could be a reasonable way to improve the quality of hybrid Pennisetum silage.