Effects of ensiling sugarcane tops with bacteria-enzyme inoculants on growth performance, nutrient digestibility, and the associated rumen microbiome in beef cattle.

Major challenges when ensiling sugarcane tops include fermentation that results in high quantities of alcohol and decrease in nutrient digestibility due to the accumulation of fiber components. Increased efforts to apply bacteria-enzyme inoculants in silage have the potential to improve nutrient digestibility. This study aimed to evaluate the effects of ensiling sugarcane tops with bacteria-enzyme inoculants or mixed bacterial inoculants on growth performance, nutrient digestibility, and rumen microbiome in beef cattle. Chopped sugarcane tops were ensiled in plastic bags for 60 d after application of 1) no inoculant (control check, CK); 2) bacteria-enzyme inoculants containing Pediococcus acidilactici, Saccharomyces cerevisiae, cellulase, and xylanase (T1, viable colony-forming units of each bacterial strain ≥108 CFU/g; enzyme activity of each enzyme ≥200 U/g); or 3) mixed bacterial inoculants containing Lactobacillus plantarum, Bacillus subtilis, and Aspergillus oryzae (T2, viable colony-forming units of each bacterial strain ≥107 CFU/g). Silages were fed to eighteen Holstein bull calves (n = 6/treatment) weighing 163.83 ±â€…7.13 kg to determine intake in a 49-d experimental period. The results showed that beef cattle-fed T1 silage or T2 silage had a significantly higher (P < 0.05) average daily gain than those fed CK silage, but the difference in dry matter intake was not significant (P > 0.05). The apparent digestibility of crude protein (CP) and acid detergent fiber (ADF) were higher (P < 0.05) for beef cattle-fed T1 silage or T2 silage than for those fed CK silage. The rumen bacterial community of beef cattle-fed T1 silage or T2 silage had a tendency to increase (P > 0.05) abundance of Firmicutes and Rikenellaceae_RC9_gut_group than those fed CK silage. Rumen fungal communities of beef cattle-fed T1 or T2 silage had a tendency to increase (P > 0.05) abundance of Mortierellomycota and of Mortierella than those fed CK silage. Spearman's rank correlation coefficient showed that the apparent digestibility of ADF for beef cattle was positively correlated with unclassified_p_Ascomycota of the fungal genera (P < 0.05). Neocalimastigomycota of the fungal phyla was strongly positively correlated with the apparent digestibility of neutral detergent fiber (NDF) (P < 0.05). Ruminococcus was positively correlated with the apparent digestibility of CP (P < 0.05). It was concluded that both T1 and T2 improved the growth performance of beef cattle by improving the ruminal apparent digestibility of CP and ADF, and had no significant impact on major rumen microbial communities in beef cattle.

Major challenges when ensiling sugarcane tops include fermentation that results in high quantities of alcohol and decrease in nutrient digestibility due to the accumulation of fiber components. Increased efforts to apply bacteria-enzyme inoculants in silage have the potential to improve nutrient digestibility. This study aimed to evaluate the effects of ensiling sugarcane tops with bacteria-enzyme inoculants or mixed bacterial inoculants on the growth performance, nutrient digestibility, and rumen microbiome in beef cattle. Chopped sugarcane tops were ensiled in plastic bags for 60 d after application of 1) no inoculant (control check, CK); 2) bacteria-enzyme inoculants (Pediococcus acidilactici, Saccharomyces cerevisiae, cellulase, and xylanase), termed treatment T1; or 3) mixed bacterial inoculants (Lactobacillus plantarum, Bacillus subtilis, and Aspergillus oryzae), termed treatment T2. Silages were fed to 18 Holstein bull calves (n = 6/treatment) weighing 163.83 ±â€…7.13 kg to determine intake in a 49-d experimental period. It was concluded that both T1 and T2 improved the growth performance of beef cattle by improving the ruminal apparent digestibility of crude protein and acid detergent fiber, and had no significant impact on major rumen microbial communities in beef cattle.

Effects of sugarcane variety and nitrogen application level on the quality and aerobic stability of sugarcane tops silage.

To better understand the effects of sugarcane variety and nitrogen application level on silage, we analyzed the fermentation quality, microbial community dynamics, and aerobic exposure of sugarcane tops silage from three sugarcane varieties (B9, C22, and T11) treated with three levels of nitrogen (0, 150, and 300 kg/ha urea). After 132 days of silage, the sugarcane tops silage produced from variety B9, with strong nitrogen fixation ability, treated with nitrogen had the highest crude protein (CP) contents, pH, and yeast counts (P < 0.05), as well as the lowest Clostridium counts (P < 0.05), and the CP increased with increasing N application level (P < 0.05). In contrast, the sugarcane tops silage produced from variety C22, with poor nitrogen fixation ability, treated with 150 kg/ha nitrogen had the highest lactic acid bacteria (LAB) counts, dry matter (DM), organic matter (OM) and lactic acid (LA) contents (P < 0.05), as well as the lowest acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents (P < 0.05). However, these results were not present in the sugarcane tops silage produced from variety T11, with no nitrogen fixation ability, whether it was treated with nitrogen or not; although the silage was treated with 300 kg/ha nitrogen, the ammonia-N (AN) content was the lowest (P < 0.05). After 14 days of aerobic exposure, Bacillus abundance increased in the sugarcane tops silage produced from variety C22 treated with 150 kg/ha nitrogen and from varieties C22 and B9 treated with 300 kg/ha nitrogen, while Monascus abundance increased in the sugarcane tops silage produced from varieties B9 and C22 treated with 300 kg/ha nitrogen and from variety B9 treated with 150 kg/ha nitrogen. However, correlation analysis showed that Monascus was positively correlated with Bacillus irrespective of nitrogen level and sugarcane variety. Our results indicated that sugarcane variety C22, with poor nitrogen fixation ability, treated with 150 kg/ha nitrogen produced the highest sugarcane tops silage quality and inhibited the proliferation of harmful microorganisms during spoilage.

Microbiome and fermentation parameters in the rumen of dairy buffalo in response to ingestion associated with a diet supplemented with cysteamine and hemp seed oil.

In this study, high-throughput gene amplicon sequencing was used to investigate the effects of 6 treatments [2 levels of hemp seed oil (HSO) × 3 levels of cysteamine (CS)] on bacterial and fungal communities in the rumen of 30 crossbred dairy buffalo. Our results indicate that the total numbers of bacterial and fungal taxa were unaffected regardless of diet (p > 0.05), while the total number of archaea was affected (p < 0.05) by the interaction of HSO and CS. Compared with control treatment, microbial composition of archaea was strongly influenced by CS (p < 0.05), while the addition of HSO, CS or both had a weak effect on fungus and bacteria. In addition, there was a significant increase in the lactic acid content with the addition of HSO, and the addition of CS to the feed caused a significant decrease in the ratio of acetic acid to propionic acid, compared with control treatment (p < 0.05). Correlation analysis showed that Acetobacter was significantly positively correlated with the genera Pichia, Klebsiella and Acinetobacter. pH was found to have a significant effect on the methanogens, and total volatile fatty acids (VFA) had a strong correlation with Butyrivibrio. The strong influence of CS on some methanogens shows that it may have potential in the development of methane reduction interventions.

Ruminal microbiota composition associated with ruminal fermentation parameters and milk yield in lactating buffalo in Guangxi, China-A preliminary study.

The ruminal microbiota of 15 dairy buffalo was characterized using high-throughput 16S rRNA gene amplicon sequencing. Results showed that Bacteroidetes was the dominant bacterial phylum in all rumen samples, followed by Firmicutes, Proteobacteria, Tenericutes and Verrucomicrobia. Butyrivibrio was positively correlated with average milk fat yield (R = 0.55; p = 0.03), average milk total solid yield (R = 0.56; p = 0.03) and standard milk yield (R = 0.52; p = 0.05). Acinetobacter were positively correlated with average milk protein yield (R = 0.56; p = 0.03), average milk total solid yield (R = 0.60; p = 0.02) and standard milk yield (R = 0.57; p = 0.03). Acetobacter was positively correlated with acetate (R = 0.63; p = 0.01), propionate content (R = 0.55; p = 0.03), butyrate content (R = 0.61; p = 0.02) and total VFA (R = 0.62; p = 0.01). The phyla Proteobacteria (R = 0.53; p = 0.04) and genus Prevotella (R = 0.52; p = 0.05) were positively correlated with butyrate content. Correlation analysis suggested that increased Butyrivibrio and Acinetobacter residing in the buffalo rumen could improve milk performance.

Analysis of the correlation between bacteria and fungi in sugarcane tops silage prior to and after aerobic exposure.

The correlation between bacteria and fungi in sugarcane tops silage prior to and after aerobic exposure was analyzed. The results showed that the abundance of Lactobacillus increased from 0.03% to 27.84% from d 0-60. Additionally, the abundance of Pichia also increased from 0.003% to 15.46% from d 0-60. Following aerobic exposure, the abundance of Lactobacillus increased by 42.39% at d 3. Moreover, Pichia was the dominant fungal genus after aerobic exposure. Spearman's correlation analysis showed that Pichia was positively correlated with the genera Lactobacillus and Pediococcus, but negatively correlated with the genera Acinetobacter, Citrobacter, and Serratia. Aspergillus, Cladosporium, and Fusarium were positively correlated with the genera Clostridium, Lactobacillus, and Pediococcus, but negatively correlated with the genera Acinetobacter, Citrobacter, and Serratia. Spearman's correlation also suggested that Aspergillus, Cladosporium, and Fusarium could be inhibited by screening Serratia, thereby reducing mycotoxins in silage.

Dynamic changes in fermentation profiles and bacterial community composition during sugarcane top silage fermentation: A preliminary study.

Investigating the dynamic changes in bacterial community composition during sugarcane top silage production starting in late March and finishing in late June (storage temperature: 20 to 35 °C) will advance our understanding of ensilage in hot ambient temperatures. The results showed that, the fermentation process was dominated by Leuconostocaceae (until d 5), followed by Lactobacillaceae (from d 5 to d 30), and finally Lactobacillaceae and Clostridium (from d 60 to d 90). As the fermentation process progressed, there was a significant increase in Lactobacillaceae abundance, and on d 60 there was a sharp increase in Clostridiaceae abundance. Spearman's correlation showed that, Lactococcus and Leuconostoc abundance were negatively correlated with acetate, propionate, butyrate, and ammonia-N levels. Clostridiaceae and Lactobacillaceae abundance were positively correlated with acetate, propionate, butyrate, and ammonia-N levels. The high moisture content (DM 24.31%) of sugarcane tops stored in hot ambient temperatures may result in butyric acid fermentation.