The objective of this study was to investigate the effects of dietary rumen-degradable starch (RDS, g/kg of DM) to rumen-degradable protein (RDP, g/kg of DM) ratios (SPR) on in vitro rumen fermentation characteristics and microbial protein synthesis (MCPS). Treatments were eight diets with SPR of 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5 and 2.6 and were formulated to be isoenergetic, isonitrogenous, and isostarch. Substrates were anaerobically incubated in sealed culture vials (100 mL) for 6, 24 or 48 h. Three incubation runs were conducted within two consecutive weeks. With the increase of the dietary SPR, the gas production (GP), in vitro dry matter disappearance (IVDMD) and concentration of MCPS and total volatile fatty acids (TVFA) linearly increased after 6 h of incubation (p ≤ 0.01), whereas they quadratically increased and peaked at the SPR of 2.3 after 24 and 48 h of incubation (p < 0.05). In response to dietary SPR increasing, the in vitro neutral detergent fiber disappearance (IVNDFD) quadratically increased (p < 0.01), and the ammonia nitrogen (NH₃-N) concentration linearly decreased (p < 0.01) after 6, 24 and 48 h of incubation. Based on the presented results, an SPR of 2.3 is recommended for formulating a diet due to its greatest IVDMD, IVNDFD, GP, TVFA and MCPS. However, as the results obtained are strictly dependent on the in vitro conditions, further in vivo studies are needed to verify our findings.

Escherichia coli counts as a major endometritis-causing pathogen among dairy cows, which lowered the economic benefits of dairy farming seriously. Probiotic consumption has been reported to impart beneficial effects on immunomodulation. However, the inflammatory regulation mechanism of probiotics on endometritis in dairy cows remains unexplored. The current work aimed to clarify the mechanism whereby Lactobacillus rhamnosus GR-1 (L. rhamnosus GR-1) resists bovine endometrial epithelial cells (BEECs) inflammatory injury induced by E. coli. The model of cellular inflammatory injury was established in the BEECs, which comes from the uterus of healthy dairy cows using E. coli. The outcome of L. rhamnosus GR-1 addition on inflammation was evaluated in BEECs with E. coli-induced endometritis. The underlying mechanisms of anti-inflammation by L. rhamnosus GR-1 were further explored in E. coli-stimulated BEECs. In accordance with the obtained results, the use L. rhamnosus GR-1 alone could not cause the change of inflammatory factors, while L. rhamnosus GR-1 could significantly alleviate the expression of E. coli-induced inflammatory factors. Based on further study, L. rhamnosus GR-1 significantly hindered the TLR4 and MyD88 expression stimulated by E. coli. Moreover, we observed that in BEECs, L. rhamnosus GR-1 could inhibit the E. coli-elicited expressions of pathway proteins that are associated with NF-κB and MAPKs. Briefly, L. rhamnosus GR-1 can effectively protect against E. coli-induced inflammatory response that may be closely related to the inhibition of TLR4 and MyD88 stimulating NF-κB and MAPKs.

K. pneumoniae is a major cause of bovine mastitis worldwide, making it difficult to control due to its resistance to multiple drugs. L. paraplantarum has been explored as a promising new approach to fighting bovine mastitis. In this study, the probiotic potential and safety of L. paraplantarum SDN1.2, as well as its ex vivo and in vivo anti-inflammatory effects against K. pneumoniae-induced mastitis, were comprehensively investigated using bioinformatics analyses and experimental validation methods. The results revealed that L. paraplantarum SDN1.2 exhibits non-hemolytic activity, is not cytotoxic, lacks virulence genes (e.g., adhesion factors, toxins, and invasion factors) and antibiotic resistance genes (e.g., beta-lactamases and tetracycline resistance genes), as supported by whole-genome sequencing, and significantly inhibits the growth of K. pneumoniae, as evaluated by antimicrobial tests. Following further validation in vitro, L. paraplantarum SDN1.2 demonstrated the capability to inhibit the adhesion and invasion of K. pneumoniae to bMECs. In a mouse model of K. pneumoniae-induced mastitis, L. paraplantarum SDN1.2 reduced the extent of neutrophil infiltration and inflammatory lesions. Furthermore, L. paraplantarum SDN1.2 pretreatment significantly reduced myeloperoxidase (MPO) activity and the expression of inflammatory cytokines (IL-6, IL-1β, and TNF-a) in mouse mammary gland tissue. In K. pneumoniae-infected bMECs, L. paraplantarum SDN1.2 significantly lowered lactate dehydrogenase (LDH) levels and expression of inflammatory cytokines such as IL-6, IL-1β, and TNF-α. The results demonstrated that the newly isolated L. paraplantarum SDN1.2 from bovine sources exhibits promising characteristics as a safe probiotic for the alleviation of bovine mastitis due to its safety profile and anti-inflammatory and antibacterial properties.

The calcium requirements of dairy cows increase dramatically soon after calving, and many cows have subclinical hypocalcemia, adversely affecting health and performance. Traditional laboratory tests for calcium are complex and not easily adapted to rapid point-of-care applications. The objectives were to evaluate a portable iCa testing device, Horiba LAQUAtwin Ca-11C, for measuring ionized calcium (iCa) in the whole blood of dairy cows and to investigate the iCa-to-total-calcium (tCa) ratio in blood collected from dairy cows within 9 days after calving. This study was conducted on two large dairies in northern China. First, blood samples were collected from 246 cows within 3 days after calving, and whole-blood iCa concentrations were measured with a Horiba LAQUAtwin Ca-11C and Abbott i-STAT 1. In addition, 885 blood samples were collected from 102 dairy cows between calving and 9 days postpartum, with iCa concentrations measured using a Horiba LAQUAtwin Ca-11C and tCa concentrations determined by a fully automated biochemical analyzer. The Horiba LAQUAtwin Ca-11C and Abbott i-STAT 1 had significant consistency in the measurement of ionized calcium concentration in whole blood (the frequency of differences between the measured values was within ±20% of the average, reaching 95.53%), and the measurement results of the two instruments were correlated (Deming regression analysis R² = 0.87). This implied the potential application of the Horiba LAQUAtwin Ca-11C as a simplified device for measuring iCa in dairy farms for on-site testing. Within the first 9 days after calving, the ratio of ionized calcium to total calcium fluctuated but overall remained within the range of 44.2 to 47.22%. Furthermore, significant variations in the ratio among individual cows indicated that individual differences and physiological states of cows affected calcium metabolism. This study identified the potential to use the Horiba LAQUAtwin Ca-11C for point-of-care testing on dairy farms. Nevertheless, the impacts of factors such as health status and individual cow differences on the ratio of ionized calcium to total calcium still require further investigation.

Corrigendum on: full citation of the original version of the article.In the published article, there was an error in [Figure 1 The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.In the published article, there was an error in [Figure 4 ZO-1 area fraction for each group. (H): The occludin area fraction for each group (I): The MUC2 area fraction for each group. Brown is immunopositive, and blue is immunonegative. The database is expressed as the mean ± SEM. Significant differences were considered at P < 0.05. Different letters are marked at bars, without the same superscripts differ significantly (P < 0.05).] appear below.The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.Reminder: Figures, tables, and images will be published under a Creative Commons CC-BY licence and permission must be obtained for use of copyrighted material from other sources (including re-published/adapted/modified/partial figures and images from the internet). It is the responsibility of the authors to acquire the licenses, to follow any citation instructions requested by third-party rights holders, and cover any supplementary charges.In the published article, there was an error. [The strain culture condition was wrong, "CO2" changed to "O2"].[Name of Sub-section if there is one], [Paragraph Number 1]. This sentence previously stated: "[The feces were fully homogenized, spread on MRS agar (Qingdao hopebiol, China), and hermetically cultured at 37℃ without CO2 for 24 h, MRS plate was sealed with a sealing membrane.]"The corrected sentence appears below: "[The feces were fully homogenized, spread on MRS agar (Qingdao hopebiol, China), and hermetically cultured at 37℃ without O2 for 24 h, MRS plate was sealed with a sealing membrane.]"The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.In the published article, there was an error. [State the mistake which was made, "CO2" changed to "O2"].A correction has been made to [2.1 Isolation, culture, and safety identification of probiotics], [Paragraph Number 1]. This sentence previously stated:PAGE \* Arabic \* MERGEFORMAT 3"[The purified bacteria were inoculated in MRS broth and static cultured at 37℃ without CO2 for 24 h, and the centrifugal tube is sealed with a sealing membrane to isolate oxygen.]"The corrected sentence appears below: "[The purified bacteria were inoculated in MRS broth and static cultured at 37℃ without O2 for 24 h, and the centrifugal tube is sealed with a sealing membrane to isolate oxygen.]"The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.In the published article, there was an error. [Unit misrepresentation, "(1% w/v)" changed to "(1% v/v)"].A correction has been made to [2.2.1 Growth and acid-producing curve curves], [Name of Subsection if there is one], [Paragraph Number 1]. This sentence previously stated: "[ The cultured solutions of isolated strains were added to 80 mL MRS broth (1% w/v) and hermetically incubated at 37℃.]"The corrected sentence appears below: "[The cultured solutions of isolated strains were added to 80 mL MRS broth (1% v/v) and hermetically incubated at 37℃.]"The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.In the published article, there was an error. [Wrong test method, "2.2.2" changed to "2.2.1"].A correction has been made to [2.2.3 Bacteriostatic substance], [Paragraph Number 1]. This sentence previously stated: "[ Use the same way as in 2.2.1 to get P. pentosaceus SNF15 supernatant. Catalase or protease K or NaOH (Beijing Solarbio Science & Technology Co., Ltd., China) was added to the supernatant of P. pentosaceus SNF15.]"The corrected sentence appears below: "[ Use the same way as in 2.2.2 to get P. pentosaceus SNF15 supernatant. Catalase or protease K or NaOH (Beijing Solarbio Science & Technology Co., Ltd., China) was added to the supernatant of P. pentosaceus SNF15.]" PAGE \* Arabic \* MERGEFORMAT 3 villi. Compared with the CN group, the intervention of P. pentosaceus SNF15 and ciprofloxacin can significantly alleviate the intestinal damage caused by E. coli K99.]"The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.In the published article, there was an error. [The test results were incorrectly described, "CK" changed to "CN"; " The secretion levels of IL-6, IL-1β, and TNF-α in the CIP, PPE, and PTE groups were significantly reduced compared with the CN group (p < 0.05) and had no significant difference with the CK group (p > 0.05)." changed to "The secretion levels of IL-6 and TNF-α in PPE group, secretion levels of IL-1β in CIP group had no significant difference with the CK group (p > 0.05)."].A correction has been made to [3.4.3 P. pentosaceus SNF15 attenuated damages in the inflammatory properties' intestinal barrier of E. coli K99-infection mice], [Paragraph Number 2]. This sentence previously stated: "[The CIP group also has the same trends with expression mRNA level, compared with secretion levels of IL-6, IL-1β, and TNF-α significantly decreased with the CK group (p < 0.05). The secretion levels of IL-6, IL-1β, and TNF-α in the CIP, PPE, and PTE groups were significantly reduced compared with the CN group (p < 0.05) and had no significant difference with the CK group (p > 0.05).]"The corrected sentence appears below: "[The...

Escherichia coli (E. col iK99) is one of the primary pathogens that cause infectious calf diarrhea, resulting in mortality and causing economic losses. Probiotics have been widely researched for their positive impact on inhibiting the growth of pathogenic bacteria and enhancing immunity and gut health as alternatives to antibiotics. This study isolated one probiotic from healthy calf feces: Pediococcus pentosaceus SNF15 (P. pentosaceus SNF15). In vitro assessments included growth character and acid-producing ability, bile salt and artificial gastroenteric fluid tolerance, Caco-2 adhesion, hemolysis screening, and antibiotic susceptibility. Whole-genome sequencing identified immunomodulatory, antimicrobial, and metabolic genes. A murine model evaluated probiotic efficacy against E. coli K99, outcomes included clinical indices (fecal score, weight), histopathology (H&E), inflammatarty factor (qRT-PCR and ELISA), tight junction proteins and mucin (immunohistochemistry detection). Finally, 16S rRNA sequencing was performed to compare the composition and relative abundance of the gut microbiota among the different groups. P. pentosaceus SNF15 demonstrated excellent growth performance and acid production capacity, bile salt and artificial gastroenteric fluid resistance, Caco-2 cells adhesion and safety (γ-hemolysis, antibiotic sensitivity) Genomic analysis revealed to immune, anti-inflammatory, antagonistic pathogens, and carbohydrate utilization, including secondary bile acid, nicotinate and nicotinamide. The animal tests showed that the P. pentosaceus SNF15 treatment protects against E. coli K99 infection, as evidenced by clinical symptoms, including weight loss, fecal score, liver atrophy, and spleen enlargement occurred histological damage. Compared with the CN group, the supplementation of P. pentosaceus SNF15 strains ameliorated the damage of jejunum and the content of tight junction proteins occludin, claudin, ZO-1, and MUC2 and decreased the levels of IL-6, IL-1β, and TNF-α in jejunum. The 16S rDNA sequence results showed that infection with Escherichia coli K99 led to an imbalance in gut microbiota; the proportion of Firmicutes and Bacteroidetes decreased, and Proteobacteria increased. P. pentosaceus SNF15 helps improve intestinal microbial composition and prevents this trend. P. pentosaceus SNF15 supplementation can prevent and treat the clinical symptoms, intestinal epithelial mucosal integrity, intestinal permeability, and immune-related cytokines and regulate the intestinal microbiota in E. coli K99-infected mice. This research revealed that P. pentosaceus SNF15 possesses desirable probiotic characteristics and could be used as a potential probiotic to remit neonatal calf diarrhea, caused by E. coli K99 infection.