Responses of nutrient utilization, rumen fermentation and microorganisms to different roughage of dairy buffaloes.

Dairy buffaloes are typically fed a high-forage, low-quality diet with high fiber. These conditions result in an inherent energy and protein inefficiency. In order to make full and rational use of feed resources and improve the production level and breeding efficiency of dairy buffaloes, the effects of various roughages on nutrient digestibility, ruminal fermentation parameters, and microorganisms in dairy buffaloes were studied in this experiment. Three ternary hybrid buffaloes, with an average body weight of 365 ± 22.1 kg, were selected and fitted with permanent rumen fistulas. They were fed six different diets, each consisting of 1 kg concentrate supplement and one of six types of roughage, including alfalfa hay (A diet), oat hay (O diet), whole corn silage (W diet), king grass (K diet), sugarcane shoot silage (S diet), and rice straw hay (R diet) according to an incomplete Latin square design of 3 × 6, respectively. The pre-feeding period of each period was 12 d. From day 13 to 15 was the official experimental period. During the prefeeding period, free feed intake for each roughage was determined, and during the experiment, the roughage was fed at 90% of the voluntary feed intake. Digestion and metabolism tests were carried out using the total manure collection method to determine the feed intake and fecal output of each buffalo, and to collect feed and fecal samples for chemical analysis. On day 15, rumen fluid samples were collected two hours after morning feeding to determine rumen fermentation parameters and bacterial 16 S rRNA high-throughput sequencing was performed. The results showed that DM and OM digestibility were greatest for the W diet and lowest for the S diet. The rumen pH of the O diet was significantly greater than that of the W diet. The concentration of rumen fluid NH3-N (mg/dL) increased with increased CP content. The concentration of total volatile fatty acids (mmol/L) in the rumen decreased with increased NDF content but increased with increased NFC content. The relative abundances of Bacteroidetes, Firmicutes, and Spirochaetes were 57.03-74.84%, 14.29-21.86%, and 0.44-1.43% in the different quality roughage groups. Bacteroidetes were mainly Prevotellaceae1 and Rikenellaceae RC_gut_group with relative abundances of 30.17-45.75% and 3.23-7.82%. The relative abundance of Patescibacteria and Spirochaetes decreased with increasing roughage quality. These results provide a theoretical and practical basis for evaluating the nutritional value of dairy buffalo feed, utilizing feed resources, matching rations, feeding scientifically, and protecting animal health.

Electroacupuncture in the treatment of IBS in rats: investigation of the mechanisms of CRH+ neurons in the paraventricular nucleus.

Electroacupuncture (EA) is well documented to treat irritable bowel syndrome (IBS). However, the mechanism of the central nervous system related to IBS and acupuncture stimulation is still not well known. In this study, a rat model of IBS was established by cold-restraint comprehensive stresses for 15 days, and it was found that the levels of corticotropin-releasing hormone (CRH), corticosterone (CORT), and adrenocorticotropic hormone (ACTH) in the peripheral serum were increased; the visceral sensitivity was enhanced; and the intestinal motility was accelerated, specifically, there was an enhancement in the discharge frequency of neurons in the paraventricular nucleus (PVN). EA treatment for 3 days, 20 min/day, alleviated the increase in the levels of CRH, CORT, and ACTH in the peripheral serum of rats, reduced the visceral sensitivity of IBS rats, and inhibited colon movement and discharge frequency of the neurons in the PVN. In addition, EA could reduce the excitability of CRH neurons and the expression of corticotropin-releasing hormone receptor 1 (CRHR1) and corticotropin-releasing hormone receptor 2 (CRHR2) in PVN. At the same time, the expression of CRH, CRHR1, and CRHR2 in the peripheral colon was decreased. Taken together, EA appears to regulate intestinal functional activity through the central CRH nervous system, revealing the central regulation mechanism of EA in IBS rats, and providing a scientific research basis for the correlation among the meridians, viscera, and brain.NEW & NOTEWORTHY The purpose of this research was to determine the central regulatory mechanism of electroacupuncture (EA) in rats with irritable bowel syndrome (IBS). Our results showed that combined with the serum changes in corticotropin-releasing hormone (CRH), corticosterone (CORT), and adrenocorticotropic hormone (ACTH), the improvement of IBS by EA was related to them. Furthermore, EA could regulate intestinal functional activity through the central CRH+ nervous system.

Impact of Seasonal Variation in Pasture on Rumen Microbial Community and Volatile Fatty Acids in Grazing Yaks: Insights from High-Altitude Environments.

The environment is one of the most important factors influencing the variation and diversity of the host gut microbiome in plateau areas. It is well-established that dietary variations substantially alter the rumen microbiota. However, there is limited research on the response of the rumen microbiota of grazing yaks to changes in seasonal diet composition under high-altitude environments. This study investigates the seasonal variations in rumen fermentation parameters, bacterial, and fungal communities in yaks, with a focus on the cold and warm seasons. Quantitative data revealed that in the cold season, yaks had an increased acetic acid proportion (p < 0.05) and acetic acid/propionic acid ratio (p < 0.05) compared to the warm season. The relative abundance of Bacteroidetes and Firmicutes were 64.67% and 25.82% in the cold season, respectively, and 66.77% and 26.87% in the warm season. The fungal community showed a higher abundance of Ascomycetes (58.72% to 76.91%) and Neocallimastigomycota in the cold season. These findings highlight the adaptation mechanisms of yaks to seasonal dietary changes and their implications for optimizing yak husbandry practices.

Exploring the Spatial Variation in the Microbiota and Bile Acid Metabolism of the Compound Stomach in Intensively Farmed Yaks.

Yaks are one of the important livestock on the Qinghai-Tibet Plateau, providing abundant dairy and meat products for the local people. The formation of these dairy and meat products mainly relies on the microbiota in their gastrointestinal tract, which digests and metabolizes plant feed. The yak's gastrointestinal microbiota is closely related to the health and production performance of the host, but the molecular mechanisms of diet-induced effects in intensively farmed yaks remain to be elucidated. In this study, 40 chyme samples were collected from the four stomach chambers of 10 intensively farmed yaks, and the bacterial diversity and bile acid changes in the rumen (SFRM), reticulum (SFRC), omasum (SFOM), and abomasum (SFAM) were systematically analyzed using 16S rRNA sequencing and bile acid metabolism. Our results showed that the gastrointestinal microbiota mainly distributes in the four-chambered stomach, with the highest microbial diversity in the reticulum. There is a highly negative correlation among the microbiota in the four chambers. The dominant bacterial phyla, Bacteroidota and Firmicutes, were identified, with Rikenellaceae_RC9_gut_group being the dominant genus, which potentially helps maintain short-chain fatty acid levels in the stomach. In contrast, the microbiome within the four stomach chambers synergistically and selectively altered the content and diversity of bile acid metabolites in response to intensive feeding. The results of this study provide new insights into the microbiota and bile acid metabolism functions in the rumen, reticulum, omasum, and abomasum of yaks. This can help uncover the role of gastrointestinal microbiota in yak growth and metabolic regulation, while also providing references for improving the production efficiency and health of ruminants.

Intensive feeding alters the rumen microbiota and its fermentation parameters in natural grazing yaks.

Introduction: Amidst the challenging environmental conditions characterized by low oxygen levels and cold temperatures on the plateau, alterations in nutrient supply emerge as pivotal factors influencing the survival and reproduction of yaks. Intensive feeding stands out as a substantial mechanism for nutrient provision, initiating discernible changes in the host's rumen flora. Within the extreme natural conditions prevailing in the plateau area of northwest Yunnan, China, there exists a con-strained comprehension of the variations in rumen microflora, fermentation parameters, and growth responses exhibited by yaks subjected to intensive feeding. Methods: This study employs 16S rRNA and ITS sequencing methods to scrutinize the rumen flora of yaks engaged in both natural grazing (G) and intensive feeding (F) on the plateau. Results: The outcomes unveil that, during the severe winter season, yaks adeptly modulate the abundance and diversity of rumen flora in response to dietary modifications under intensive feeding, aiming to optimize the efficient utilization of dietary fiber and energy. Principal Coordinate Analysis (PCoA) illustrates a substantial alteration in the rumen microbial community of naturally grazing yaks when exposed to intensive feeding. The natural grazing group manifests a higher prevalence of Firmicutes and Bacteroidetes, while the intensive feeding group exhibits heightened levels of Prevotella in the rumen. The Rikenellaceae _ RC9 _ gut_ group, associated with mycobacteria, prevails more abundantly in the natural grazing setting. PICRUSt2 analysis indicates that intensive feeding induces bacterial gene overexpression linked to protein metabolism. Rumen fungi showcase heightened diversity under intensification. Intensive feeding results in an augmented abundance of non-fiber-degrading bacteria and semi-fiber-degrading bacteria, accompanied by elevated concentrations of Volatile Fatty Acids (VFA). Discussion: These findings yield novel insights into the shifts in the rumen microflora of yaks acclimated to intensive feeding in high-altitude environments, provide an important reference for the nutritional regulation of supplemental feeding of natural grazing yaks in the cold season, ultimately contributing to their enhanced growth.