Journal of Dairy Science最新文献

{"title":"A systematic review: methods to measure total mixed ration uniformity.","authors":"Isabela G M A Santos, Amy R Reibman, Jacquelyn P Boerman","doi":"10.3168/jds.2026-28913","DOIUrl":"https://doi.org/10.3168/jds.2026-28913","url":null,"abstract":"<p><p>A uniform TMR ensures that the diet being delivered to the cows is consistent across time, both within a batch and across days. A systematic literature review was conducted to describe the different methods that have been utilized to measure within-batch TMR uniformity. Scientific papers that utilized methods to measure TMR uniformity were identified through a search in the Scopus database, which was conducted with no restrictions on the date of study publication or publication type. After filtering processes, 22 papers were selected for full review based on their relevance to within-batch TMR uniformity. Of the studies reviewed, 11 utilized particle size-based methods such as the Penn State Particle Separator (PSPS), 4 utilized tracer-based methods, 7 utilized nutrient analyses, 4 utilized near-infrared spectroscopy (NIRS), and 4 utilized image analysis or modeling techniques. Overall, there is no standardized or universally accepted method to assess TMR uniformity. Importantly, the methods identified should not be interpreted as equivalent, as each captures different aspects of uniformity, including physical structure, ingredient distribution, and chemical composition. Direct measurement methods, such as particle size and nutrient analysis, provide valuable information but are often labor-intensive and time-consuming. Indirect approaches, such as NIRS and image analysis, offer promising alternatives by reducing labor requirements and enabling faster or real-time assessments, although they still require further validation under practical feeding conditions. Therefore, future developments should focus on integrating physical, chemical, and optical indicators into cost-effective, automated tools capable of supporting routine monitoring of TMR uniformity in precision feeding systems.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148917903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Complementarity of portable and benchtop near-infrared spectrometers for microplastic predictive detection in whole camel milk powder.","authors":"Xiao Zhiming, Zheng Wenxin, Feng Yuchao, Li Runxian, Suo Decheng, Fan Xia","doi":"10.3168/jds.2026-28796","DOIUrl":"https://doi.org/10.3168/jds.2026-28796","url":null,"abstract":"<p><p>This study systematically investigated the complementarity and transferability of benchtop and portable Near Infrared Spectroscopy regarding the detection of common microplastic contamination in camel milk powder (CMP). Both devices achieved superior results in the Support Vector Machine (SVM) discrimination of microplastic contamination types and demonstrated complementarity in the precise identification of pure CMP and its PET contaminated samples. A data level fusion strategy combined with SVM discriminant analysis reduced the classification error of PE, PET, and PS contaminated CMP samples to 0. Benchtop spectrometers were significantly superior to portable devices in the quantitative analysis of microplastic contamination levels, with cross validation coefficients of determination ranging from 0.789 to 0.899 and 0.526-0.717, respectively. Furthermore, the Slope Bias Correction method successfully implemented model transfer; the prediction accuracy of the portable device for PP contaminated samples after correction (R² = 0.796) was improved by 51.10% compared with the original model (R² = 0.526). This study provides a theoretical basis and technical pathway for the rapid onsite screening of microplastic contamination in CMP.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148917906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lowering dietary crude protein and cation-anion difference to reduce manure ammonia emissions in lactating cows.","authors":"J Kim, H Hu, K Park, B Bae, Y A Ben-Meir, C Lee","doi":"10.3168/jds.2026-28628","DOIUrl":"https://doi.org/10.3168/jds.2026-28628","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The objectives of the study were to determine the effects of reducing dietary CP, reducing DCAD, or the combination of reducing CP and DCAD on lactation performance and manure NH&lt;sub&gt;3&lt;/sub&gt; emissions. A total of 16 mid-lactating Holstein cows were used in a replicated 4 × 4 Latin square design with a 21-d period consisting of 14-d diet adaptation and 7-d sample collection. Cows were randomly assigned to: CON, a control diet (17.0% CP and 221 mEq/kg DCAD on a DM basis); RCP, a reduced-CP diet (15.2% CP and 221.4 mEq/kg DCAD on a DM basis); RDCAD, a reduced-DCAD diet (16.8% CP and -11 mEq/kg DCAD on a DM basis) supplemented with fatty acids (FA) enriched with C16:0 and a Met analog; and RCP-RDCAD, a reduced-CP and DCAD diet (15.4% CP and -11.5 mEq/kg DCAD on a DM basis) supplemented with the FA enriched with C16:0 and Met analog. Samples were collected from individual cows to determine total-tract nutrient digestibility, N utilization, blood metabolites, and milk FA composition. Manure of individual cows was incubated over 6 d using a continuous air flux chamber system to determine NH&lt;sub&gt;3&lt;/sub&gt; emissions. Reducing dietary CP (RCP + RCP-RDCAD vs. CON + RDCAD) did not affect DMI but decreased milk yield (40.9 vs. 41.8 kg/d) and milk protein yield (1.38 vs. 1.42 kg/d). Furthermore, reducing CP tended to decrease NDF digestibility (47.4 vs. 49.2%). Plasma concentration of total EAA decreased for cows fed the reduced-CP diets. Reducing dietary CP increased milk N secretion (33.2 vs. 30.9%) and decreased urinary N excretion (29.9 vs. 32.9%) as a proportion of N intake. Manures of cows fed the reduced-CP diets decreased cumulative NH&lt;sub&gt;3&lt;/sub&gt; emissions by 35%. Reducing DCAD (RDCAD + RCP-RDCAD vs. CON + RCP) decreased DMI, milk yield (40.0 vs. 42.7 kg/d), milk fat yield (1.79 vs. 1.90 kg/d), and milk protein yield (1.34 vs. 1.46 kg/d). Reducing DCAD tended to increase total-tract digestibility of NDF (49.1 vs. 47.4%) and decreased the concentration of trans-10 C18:1 in milk FA, probably because of supplementation of palmitic acid and a Met analog. Increases in BUN and MUN were observed when the reduced-DCAD diets were fed, suggesting inefficient N utilization. Various blood metabolites and gases were affected and urine pH decreased (6.41 vs. 8.01) when cows were fed the reduced-DCAD diets, suggesting compensated metabolic acidosis. The cumulative NH&lt;sub&gt;3&lt;/sub&gt; emissions from manure decreased by 21% for cows fed the reduced-DCAD diets. An interaction between CP and DCAD for NH&lt;sub&gt;3&lt;/sub&gt; emissions from manure occurred because RCP or RDCAD decreased NH&lt;sub&gt;3&lt;/sub&gt; emissions but the mitigation for RCP-RDCAD was lower than the sum of the reductions observed for RCP and RDCAD separately. In conclusion, reducing CP or DCAD was effective in lowering NH&lt;sub&gt;3&lt;/sub&gt; emissions from manure, and the combination further decreased NH&lt;sub&gt;3&lt;/sub&gt; emissions although the mitigation was not additive. Despite these potential environmental benefits, the reduced-","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148917771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and evaluation of a computer vision system for identifying mastitis-related pathogens in dairy cows from bacterial culture media.","authors":"M Wieland, W Flanders, A Singh, J Runyan, C Guarino, P Basran","doi":"10.3168/jds.2026-28858","DOIUrl":"https://doi.org/10.3168/jds.2026-28858","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The objective of this study was to investigate the diagnostic accuracy of a computer vision system for identifying mastitis pathogens from tryptic soy agar plates containing 5% sheep blood. We used isolates of the following mastitis pathogens: Escherichia coli, Klebsiella pneumoniae, Lactococcus lactis, Staphylococcus aureus, Staphylococcus chromogenes, Streptococcus dysgalactiae, Streptococcus infantarius, and Streptococcus uberis. In addition, a 'no growth' category was included to represent samples in which no bacterial growth was detected. After primary culture and pathogen identification at the species level by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF), a representative colony was selected and subcultured, and plates were incubated at 37°C for 48 h. After 24 h of incubation, a representative colony from each plate was submitted for MALDI-TOF analysis, which served as the gold standard. Images were obtained at 24 and 48 h of incubation using a digital camera and a custom-made light box. A custom convolutional neural network architecture was designed to predict pathogen classification from digital images obtained at 24 and 48 h. We calculated the overall accuracy, diagnostic test statistics [sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV)], and the area under the curve (AUC) of the receiver operating characteristic (ROC) curves to assess the models' performance in detecting the different pathogen categories. The overall classification accuracy was 74.0% for the 24-h model and 72.8% for the 48-h model. The mean ROC AUC was 0.950 for the 24-h model and 0.943 for the 48-h model, indicating strong separability among pathogen categories. Sensitivity, specificity, PPV, and NPV for the 24-model were E. coli, 0.79, 0.97, 0.74, 0.97; K. pneumoniae, 0.71, 0.93, 0.60, 0.96; L. lactis, 0.51, 0.94, 0.52, 0.94; Staph. aureus, 0.53, 0.98, 0.71, 0.95; Staph. chromogenes, 0.78, 0.98, 0.86, 0.97; Strep. dysgalactiae, 0.77, 0.99, 0.84, 0.98; Strep. infantarius, 0.46, 0.97, 0.64, 0.93; Strep. uberis, 1.00, 0.95, 0.72, 1.00; and 'no growth', 1.00, 1.00, 1.00, 1.00; and for the 48-h model E. coli, 0.96, 0.98, 0.86, 0.99; K. pneumoniae, 0.72, 0.97, 0.76, 0.96; L. lactis, 0.47, 0.92, 0.37, 0.95; Staph. aureus, 0.55, 0.97, 0.67, 0.95; Staph. chromogenes, 0.74, 0.96, 0.69, 0.97; Strep. dysgalactiae, 0.86, 0.98, 0.83, 0.99; Strep. infantarius, 0.43, 0.95, 0.56, 0.92; Strep. uberis, 0.78, 0.97, 0.74, 0.98; and 'no growth', 1.00, 1.00, 0.98, 1.00. When pathogen predictions were grouped according to antimicrobial treatment recommendation (treatment vs. no treatment), the 24-h and 48-h models achieved sensitivities of 90.8% and 92.3%, specificities of 92.9% and 90.1%, PPV of 95.9% and 93.9%, NPV of 84.4% and 87.8%, accuracies of 91.5% and 91.5%, and F1 scores of 93.3% and 93.0%, respectively. Our results indicate that the computer vision system developed in this study can acc","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148917871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of vitamin B inclusion rates in milk replacer on health and growth of preweaned Holstein-Angus crossbred calves.","authors":"M L Pister, K N Brost, A Saito, J K Drackley","doi":"10.3168/jds.2026-29095","DOIUrl":"https://doi.org/10.3168/jds.2026-29095","url":null,"abstract":"<p><p>The adequacy of current recommendations for B-vitamin content of milk replacer has received little research attention, particularly with producers feeding more milk than historical standards. The aim of this study was to evaluate the effects of varying inclusion levels of B vitamins in milk replacer (MR) on health and growth of preweaned calves through 9 wk of age. Forty-two Holstein-Angus cross calves (≤7 d old) were randomly assigned to 1 of 3 treatments: control (CON, basal MR with no added B vitamins), basal plus (BP, MR with moderate B vitamin supplementation: 1.9 mg/kg B₁, 1.7 mg/kg B₃, 0.3 mg/kg B₆, 43 µg/kg B₁₂), or NASEM plus (NP, MR with supplemented B vitamins above current recommendations: 19.5 mg/kg B₁, 9.9 mg/kg B₂, 30 mg/kg B₃, 19.5 mg/kg B₆, 210 µg/kg B₁₂,0.04 mg/kg biotin, 1.4 mg/kg folic acid, and 19.6 mg/kg pantothenic acid). The non-supplemented CON was below current recommendations for all B vitamins except biotin.and pantothenic acid Calves were housed individually and fed MR using a step-up/step-down protocol. Water was offered ad libitum from d 0; starter feed was offered ad libitum starting on d 50. Health scores and MR intake were recorded twice daily; starter intake, coprophagia, and fecal color were recorded daily. Weekly measurements included BW and skeletal growth. Health outcomes were analyzed using GLIMMIX, and growth and intake data using MIXED procedures in SAS. No clinical signs of vitamin deficiency were observed. Compared with BP calves, CON calves had more days with ocular discharge, while BP calves tended to have more respiratory events (coughing, heavy breathing) than CON. Starter intake was greater in BP vs CON during wk 8-9. The NP calves tended to have increased withers height compared with CON. No significant differences were observed in MR intake, BW, or most growth metrics. In summary, B vitamin supplementation showed some health benefits, though effects varied by inclusion level. Increased starter intake in BP calves may reflect improved well-being, although gains in growth were limited. Further research is needed to define optimal B vitamin inclusion rates in preweaned calf nutrition.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148917922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of sample size, content range, and sample removal on slope and bias correction in Fourier-transform mid-infrared spectroscopy for milk fatty acids.","authors":"M Matamura, E Abe, N Nagahaka, T Mishima, T Shibata, M Kondo","doi":"10.3168/jds.2026-28333","DOIUrl":"https://doi.org/10.3168/jds.2026-28333","url":null,"abstract":"<p><p>This study examined how calibration sample size, fatty acid (FA) content range, and sample removal threshold influence the performance of slope and bias correction (SBC) during calibration transfer for Fourier-transform mid-infrared (FT-MIR) prediction of milk FA. A total of 143 producer milk samples, consisting of 92 individual cow milk samples and 51 bulk tank milk samples, were analyzed using FT-MIR spectroscopy and gas chromatography reference analysis. Prediction accuracy was first evaluated for de novo, mixed, and preformed FA using all 143 samples before and after SBC. De novo and mixed FA showed high prediction accuracy before SBC, with relative root mean square error (relRMSE) values of 4.46% and 7.85%, respectively, and only marginal improvements after SBC. In contrast, preformed FA showed lower initial prediction accuracy, with relRMSE decreasing from 17.6% before SBC to 5.81% after SBC. Therefore, subsequent numerical simulations focused on preformed FA. Calibration subsets of 3 to 30 samples were generated by 100,000 random samplings for each subset size, and SBC performance was evaluated with and without sample removal based on relative difference thresholds of 20 to 90%. The proportion of iterations achieving acceptable prediction accuracy (relRMSE ≤10%) generally increased with calibration subset size and was improved by moderate sample removal thresholds. At n = 7, moderate removal thresholds yielded acceptable accuracy in approximately 95% of iterations, suggesting that n = 7 may be a minimum practical candidate. More stable performance was observed at n ≥ 10, and n ≥ 15 achieved acceptable accuracy in almost all iterations under most conditions. Although wider FA content ranges were generally obtained as calibration subset size increased, subsets with the widest content range did not necessarily show the highest prediction accuracy, indicating that content range alone does not determine SBC performance. These findings indicate that effective SBC requires calibration subsets that represent not only FA content range but also the prediction error structure of the target population. The results provide practical guidance for constructing efficient calibration subsets for routine FT-MIR milk FA analysis.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148917923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the plasmin system: From skim milk to milk protein concentrate.","authors":"Tyler R Jarrard, Qihui Wu, Hari Meletharayil, Haotian Zheng","doi":"10.3168/jds.2026-28964","DOIUrl":"https://doi.org/10.3168/jds.2026-28964","url":null,"abstract":"<p><p>In milk protein concentrate manufacturing, activators and inhibitors of the plasmin system are concentrated together, thus working against one another and thus making predictions for levels of plasmin-driven proteolysis in MPCs difficult. Moreover, it is reasonable to hypothesize that the concentrated plasmin system enzymes could have induced alterations in their individual activities. Therefore, it is impossible to predict the net effect of milk protein concentration on the potential or risks of proteolysis of model beverages made from MPC. The aim of this work is to characterize plasmin-system activities in MPC85, a common milk-beverage ingredient. In this study, MPC85 powder was manufactured using a pilot-scale membrane ultrafiltration unit and a mini-spray dryer. Fluorescence of N-Succinyl-Ala-Phe-Lys-7-amido-4-methylcoumarin (Suc-Ala-Phe-Lys-AMC) was used to assess apparent plasmin activity in MPC85 and its processing streams. Additionally, the extent of casein hydrolysis at different aging periods (d 0, 3, 7, and 14 at 37°C) was determined using liquid chromatography. The UF+DF process and spray drying, respectively, did not impact apparent plasmin activities on a solids basis. However, at the early storage stage (d 3), casein proteolysis in MPC85 powder (∼76%) was not statistically different from the feed milk (∼67%). After 14 d, casein proteolysis was nearly complete (>90%) for all samples. These obtained results suggest that concentration of milk proteins enhances competitive inhibition in fluorescent plasmin assays, and that the true rate of casein hydrolysis by plasmin does not greatly change in MPC85 relative to milk. Moreover, both plasmin and plasminogen activator activities rose during storage, likely due to plasminogen activation and conversion of the activator to its 2-chain form by plasmin. These findings illustrate the impacts of MPC processing on the dynamics of plasmin activity and proteolysis over a controlled storage period. This knowledge may guide and motivate further research on improving MPC85 quality attributes by reducing its proteolytic potential in diverse food formulas.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148917992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep learning-based classification of wakefulness, sleep, and rumination states in dairy cows from polysomnography and RumiWatch data.","authors":"Chuanyi Guo, Emma Ternman, Xinjie Zhao, Kai Liu, Mutian Niu","doi":"10.3168/jds.2026-28809","DOIUrl":"https://doi.org/10.3168/jds.2026-28809","url":null,"abstract":"<p><p>Sleep is essential for the health and welfare of dairy cattle, yet accurate monitoring remains challenging. While Polysomnography (PSG) serves as the gold standard for sleep assessment, its reliance on labor-intensive manual scoring of physiological signals constrains on-farm application, underscoring the need for accessible sensor systems such as the RumiWatch System (RWS). This study proposed DairySleepNet, a deep learning framework based on a selective state space model, for automated classification of wakefulness, sleep, and rumination states using PSG and RWS data, with the aim of supporting scalable annotations and on-farm deployment. The proposed framework adopted a 2-stage encoding architecture that effectively processed time-frequency representations converted from raw multichannel signals through the short-time Fourier transform, capturing both within-channel temporal features and cross-channel interactions. The method was evaluated using 77.13 h of usable PSG and RWS recordings from 7 cows, with approximately one 12-h segment retained for each cow. Animal-level cross-validation and a soft weighted sampling strategy were implemented to ensure robust evaluation. Experimental results demonstrated that DairySleepNet achieved a macro F1 of 86.37% and an accuracy of 90.80% when using PSG data, markedly outperforming both Transformer-based and machine learning baselines. These results supported the feasibility of automated sleep annotation from PSG recordings. Although combining PSG and RWS data reduced cross-fold variability, it did not improve the overall system performance. By contrast, classification based solely on RWS data remained unsatisfactory, underscoring the need for further methodological development before reliable on-farm sleep monitoring can be achieved. Future work should prioritize fine-grained sleep staging, currently limited by scarce stage-specific labeled data, and broader data collection across diverse farm environments to enable robust and practical on-farm application.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148917873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Replacing conventional magnesium oxide with high-solubility magnesium oxide while reducing sodium bicarbonate improves ruminal pH and fiber digestibility.","authors":"Sharif Uddin Khan, Jonas de Souza, Sriniwas Pandey, Benjamin Wenner, KwangCheol Casey Jeong, Fernanda Batistel","doi":"10.3168/jds.2026-29098","DOIUrl":"https://doi.org/10.3168/jds.2026-29098","url":null,"abstract":"<p><p>High-starch diets increase dietary energy density for high-producing dairy cows but also increase ruminal acid production and the risk of ruminal pH depression. High-solubility magnesium oxide has emerged as a potential ruminal alkalinizing agent; however, whether it can replace conventional low-solubility magnesium oxide while reducing sodium bicarbonate inclusion under different dietary starch concentrations remains unclear. The objective of this study was to evaluate the effects of partially replacing sodium bicarbonate with high-solubility magnesium oxide on ruminal pH, fermentation, nutrient digestibility, nitrogen metabolism, and bacterial community composition using dual-flow continuous culture fermenters. Treatments were arranged in a 2 × 2 factorial design with 2 dietary starch concentrations [low starch (21% of DM) and high starch (32% of DM)] and 2 pH-modulation strategies: a high dose of sodium bicarbonate (0.66% of dietary DM) plus low-solubility magnesium oxide (0.40% of dietary DM), or a low dose of sodium bicarbonate (0.30% of dietary DM) plus high-solubility magnesium oxide (0.40% of dietary DM). No pH-modulation strategy × starch concentration interactions were detected. Across starch concentrations, the low-dose sodium bicarbonate plus high-solubility magnesium oxide treatment increased ruminal pH and improved OM, NDF, ADF, and hemicellulose digestibility, whereas SCFA production, nitrogen metabolism, and bacterial community composition were largely unaffected. Increasing dietary starch reduced ruminal pH and nutrient digestibility while altering SCFA profiles, nitrogen metabolism, and bacterial community structure. Overall, partially replacing sodium bicarbonate while replacing conventional low-solubility magnesium oxide with high-solubility magnesium oxide improved ruminal pH and fiber digestibility across contrasting dietary starch concentrations, indicating that this strategy can reduce sodium bicarbonate inclusion without compromising ruminal function.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148917788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A randomized field study comparing 2 cautery disbudding techniques on wound healing in dairy calves.","authors":"A Singh, S Mann, A Grosul, M Wieland","doi":"10.3168/jds.2026-28823","DOIUrl":"https://doi.org/10.3168/jds.2026-28823","url":null,"abstract":"<p><p>Disbudding is a routine management practice on dairy farms, and cautery disbudding remains the most popular method in North America. Practitioners commonly employ 2 methods of cautery disbudding: retaining (BUD-IN) or removing (BUD-OUT) the cauterized horn bud. However, comparative evidence regarding healing and pain outcomes between these techniques is limited. The objective of this study was to compare pain sensitivity, wound characteristics, healing outcomes, and growth performance following cautery disbudding with BUD-IN or BUD-OUT in heifer dairy calves. We hypothesized that pain sensitivity and wound healing characteristics would differ between these 2 cautery disbudding methods. A total of 222 healthy female Holstein calves were enrolled at 16 d of age on a commercial dairy farm in New York and randomly assigned to BUD-IN (n = 111) or BUD-OUT (n = 111) treatment groups. All calves received meloxicam (1 mg/kg BW, orally) and a cornual nerve block with 5 mL of 2% lidocaine before disbudding. Wound diameter was the primary outcome variable. Other secondary outcome variables were mechanical nociceptive threshold (MNT), wound discharge, wound healing score, and calf health. All outcome variables were assessed weekly for 8 wk. Body weight was measured at disbudding (wk 0) and 8 wk after disbudding. The continuous outcomes MNT, wound diameter, and ADG were analyzed using generalized linear mixed models; the binary outcome (presence or absence of wound discharge) was analyzed using logistic regression; and time to complete healing was analyzed using Cox proportional hazards regression. Mechanical nociceptive threshold and wound diameter did not differ between groups. Wound discharge was observed during the initial 4 wk post-disbudding. Purulent wound discharge was more common in BUD-IN than BUD-OUT, with an odds ratio (95% CI) of purulent wound discharge in BUD-IN. Time to complete wound healing did not differ between treatments. Average daily gain was not different among groups. Under the conditions of this study, removal of the horn bud during cautery disbudding did not affect pain sensitivity, growth performance, or time to wound healing but was associated with reduced odds of early wound discharge. These findings suggest that both techniques produce comparable long-term outcomes when appropriate analgesia is provided, and the selection of technique may be guided by early wound management considerations.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148917864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}