Consequences of herbal mixture supplementation on milk performance, ruminal fermentation, and bacterial diversity in water buffaloes

Breed-Specific Responses and Ruminal Microbiome Shifts in Dairy Cows Under Heat Stress

Holstein and Jersey cows, as excellent dairy breeds, have their own advantages in milk yield, milk quality, disease resistance, and heat resistance. However, the adaptability and rumen microbiome changes in Holstein and Jersey cows under heat stress are not clear. Therefore, the main objective of this study was to compare the differences in heat tolerance and the changes in the ruminal microbiome in Holstein and Jersey cows under heat stress. The experiment comprised a 7-day thermo-neutral (TN) period and a 7-day heat stress (HS) period. Five Jersey cows and five Holstein cows with similar parity and days in milk were selected, and rumen fluid was collected from five of them each. Compared with the TN period, heat stress increased the respiratory rate (p < 0.05), whereas decreased the milk yield (p < 0.01) in the Holstein and Jersey cows. Also, heat stress increased the rectal temperature (p < 0.01) in the Holstein cows. Jersey cows had a significantly (p < 0.05) lower level of acetic acid, propionic acid, butyric acid, valeric acid, and TVFA during HS compared with the TN period. Furthermore, high-throughput sequencing revealed that the relative abundance of Bacteroidetes and Prevotella increased while the relative abundance of Firmicutes decreased in Holstein cows during the HS period, whereas Christensenellaceae and Clostridium were more abundant in Jersey cows during the HS period than in the TN period. Simultaneously, the dominant fungi in Holstein cows were Ascomycota, Neocallimastigomycota, and Aspergillus. Correlation analysis also provided a link between the significantly altered rumen microbiota and animal production. These results suggest that heat stress has negatively influenced the physiological parameters, milk production, and rumen microbiota of Holstein and Jersey cows. Changes in the rumen fermentation and ruminal microbiome in Holstein cows may be associated with a better adaptation ability to heat stress. Our findings may inform future research to better understand how heat stress affects the physiology and productivity of dairy cattle breeding in southern China and the development of mitigation strategies.

Effects of Supplementation with an Herbal Mixture on the Antioxidant Capacity of Milk

The aim of this study was to assess the effect of the addition of a standardized herbal mixture to the feed ration for Holstein-Friesian cows on the antioxidant capacity of milk. The study was carried out on a farm specialized in breeding dairy cattle. The exact study involved 30 cows in lactation III, which were in the first phase of lactation at the beginning of the experiment (15 cows-control group; 15 cows-experimental group). The nutrition supplied to the cows was based on the TMR (total mixed ration) system, with roughage and concentrate fodder used as the basis of the feed ration. The addition of a standardized blend of dried herbs, i.e., oregano (Origanum vulgare), thyme (Thymus vulgaris), purple coneflower (Echinacea purpurea), and cinnamon bark (Cinnamomum zeylanicum), was the experimental factor. Powdered herbs were administered as a component of the concentrate fodder at the dose of 3% DM ration/day/head. Milk samples were collected four times during the experiment (term 0 after the colostrum period and then after lactation weeks 2, 4, and 6). The following parameters were determined in the milk: the basic chemical composition, i.e., the content of total protein, fat, lactose, and casein; somatic cell count; content of selected whey proteins (α-lactalbumin, β-lactoglobulin, lactoferrin, BSA); and fat-soluble vitamins (A, D₃, E). Additionally, the milk antioxidant capacity (ABTS, FRAP, DPPH) was determined and the degree of antioxidant protection (DAP) was calculated. It was shown that the milk from cows receiving the herbal blend-supplemented fodder had a higher content of casein, compared to the control group. The herbal supplementation contributed to a significant increase in the content of bioactive compounds, i.e., selected whey proteins (β-lactoglobulin, lactoferrin) and lipophilic vitamins (A, E). The milk was also characterized by significantly higher antioxidant potential (regardless of the measurement method) and a higher degree of antioxidant protection (DAP).

Effects of mixed sugarcane tops and napiergrass silages on fermentative quality, nutritional value, and milk yield in water buffaloes

The objective of this study was to evaluate the effects of sugarcane tops (STs) and napiergrass (NG) silage on fermentative quality, nutritional value and milk yield in water buffaloes. Silage were prepared either conventionally without ST (C) or mixed with 25% (S1), 50% (S2), and 75% (S3) ST based on fresh matter. Twenty-eight lactating buffaloes were divided into four groups with seven replicates and fed four experimental diets containing the corresponding silages. The S3 silage fermented well with a higher (P < 0.05) lactic acid content and lower (P < 0.05) pH and ammonia-N level than those of other mixed silage. Silage with increasing ST proportions showed a significant increase (P < 0.05) in the apparent digestibility of dry matter, crude protein, organic matter, and gross energy. As a result, water buffalo fed S3 silage increased dry matter intake (P < 0.05) and tended to have higher milk yield and feed efficiency as compared with the C group. Our study indicates that adding ST improves NG silage fermentation and enhances the nutrient digestibility and milk production in water buffaloes, and mixing ratio of 25%NG and 75%ST had the highest lactate fermentation quality and presented a high feed value.

Effect of Hydrogen-Consuming Compounds on In Vitro Ruminal Fermentation, Fatty Acids Profile, and Microbial Community in Water Buffalo

The present study aimed to investigate the effect of hydrogen-consuming compounds on ruminal methane (CH4) production, in vitro fermentation parameters, fatty acids profile, and microbial community in water buffalo. Different sodium nitrate to disodium fumarate ratios [2:1 (F), 1:1 (S), 1:2 (T)] were studied in vitro by batch culture technique in the presence of linoleic acid. Results revealed that the dominant bacterial communities were not affected with sodium nitrate and disodium fumarate, whereas CH4 production and Verrucomicrobia, Succiniclasticum, norank_f__Muribaculaceae, and Prevotellaceae_UCG-003 were reduced (P < 0.05). However, ruminal pH, unsaturated fatty acids/saturated fatty acids (UFA/SFA) and Campilobacterota, Selenomonas, Succinivibrio, Oribacterium, Christensenellaceae_R-7_group, Campylobacter, Shuttleworthia, Schwartzia, and Prevotellaceae_YAB2003_group were increased (P < 0.05). Total volatile fatty acids (TVFA) and Spirochaetae, Fibrobacterota, Verrucomicrobia, Fibrobacter, Treponema, and Prevotellaceae were decreased in F (P < 0.05), but cis-9, trans-11CLA, acetate/propionate and Proteobacteria, Campilobacterota, Selenomonas, Succinivibrio, and Campylobacter were increased in F (P < 0.05). The highly selected bacterial genera in F were Campylobacter and Succinivibrio. The disodium fumarate, enhanced (P < 0.05) the TVFA, propionate, total bacteria, Butyrivibrio proteoclasticus, and Atypical butyrivibrio. The concentrations of C18:3n3, C20:3n6, C21:0, C22:2n6, and C22:1n9, as well as the populations of total fungi, protozoa, methanogens, Butyrivibrio hungatei in T were higher (P < 0.05). The highly selected bacterial genera in T were Fibrobacter and Treponema. Conclusively, the addition of sodium nitrate and disodium fumarate can reduce the CH4 production and optimize ruminal fatty acid composition. Furthermore, disodium fumarate can alleviate the adverse effect of sodium nitrate on the rumen fermentation.

Heat Stress Induces Shifts in the Rumen Bacteria and Metabolome of Buffalo

Exposure to the stress (HS) negatively affects physiology, performance, reproduction and welfare of buffalo. However, the mechanisms by which HS negatively affects rumen bacteria and its associated metabolism in buffalo are not well known yet. This study aimed to gain insight into the adaption of bacteria and the complexity of the metabolome in the rumen of six buffalo during HS using 16S rDNA and gas chromatography metabolomics analyses. HS increased respiratory rate (p < 0.05) and skin temperature (p < 0.01), and it decreased the content of acetic acid (p < 0.05) and butyric acid (p < 0.05) in the rumen. Omics sequencing revealed that the relative abundances of Lachnospirales, Lachnospiraceae, Lachnospiraceae_NK3A20_group and Clostridia_UCG-014 were significantly (p < 0.01) higher under HS than non-heat stress conditions. Several bacteria at different levels, such as Lactobacillales, Streptococcus, Leuconostocaceae and Leissella, were significantly (p < 0.05) more abundant in the rumen of the non-heat stress than HS condition. Thirty-two significantly different metabolites closely related to HS were identified (p < 0.05). Metabolic pathway analysis revealed four key pathways: D-Alanine metabolism; Lysine degradation, Tropane; piperidine and pyridine alkaloid biosynthesis; and Galactose metabolism. In summary, HS may negatively affected rumen fermentation efficiency and changed the composition of rumen community and metabolic function.