Journal of Dairy Science最新文献

{"title":"Development of prediction equations for IgA, IgG, and IgM concentrations in mature milk from Holstein cows using milk infrared spectral data.","authors":"Yuri Satake, Teppei Katsura, Tao Zhuang, Megumi Urakawa, Yugo Mineshima, Toshimi Baba, Gaku Yoshida, Haruki Kitazawa, Hitoshi Shirakawa, Takehiko Nakamura, Tomonori Nochi, Yoshifumi Sakai, Masahiro Satoh, Satoshi Haga, Hisashi Aso, Yoshinobu Uemoto","doi":"10.3168/jds.2024-25991","DOIUrl":"https://doi.org/10.3168/jds.2024-25991","url":null,"abstract":"<p><p>Ig in ruminant mammary secretions play a central role in active immune protection of the mammary gland against infections. Ig are present in both colostrum and milk from cows, and interest in routinely quantifying the Ig content in milk for herd management and genetic improvement of disease resistance is increasing. Therefore, the objective of this study was to develop a prediction equation for Ig (IgA, IgG, and IgM) concentrations in milk from Holstein cows using milk Fourier-transform infrared (FTIR) spectral data and to evaluate the practical feasibility of the predicted Ig concentration in milk. First, we developed prediction equations for Ig concentrations in milk using 1,633 milk samples comprising both Ig concentrations in milk and milk FTIR spectral data. We then evaluated the predictive accuracy of the developed equations using 3 different factors: derivative preprocessing, spectral wavenumber ranges, and regression models. Our results demonstrated that the prediction equations based on the partial least squares regression and 4 machine learning regression models exhibited the highest predictive accuracy for all traits under the conditions of nonderivative preprocessing and spectral wavenumber range related to milk quality traits. Their predictive accuracies were moderate, with the R² ranging from 0.41 to 0.42, 0.50 to 0.52, and 0.38 to 0.39 for IgA, IgG, and IgM, respectively. Second, we evaluated the practical applicability of the predicted Ig concentration by comparing the trends of both the observed and predicted Ig concentrations with respect to several environmental effects. A linear model was applied using the observed and predicted Ig concentrations, and the LSM of the levels for each environmental effect (lactation stage, SCS, parity, and milk yield) was estimated. Our results showed that the estimated environmental effects of the observed and predicted values showed similar trends for all traits. These results indicate that it is possible to estimate environmental effects using the predicted values obtained via the prediction equation with moderate accuracy. Although the predictive accuracy obtained here may be effective for estimating effects at the herd level, further improvement in predictive accuracy is necessary for estimating effects at the cow level.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143954924","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":"Fabrication and characterization of glucono-δ-lactone-induced cold-set emulsion gels stabilized by a whey and pea protein mixture at various mixing ratios for the delivery of curcumin.","authors":"Ru Zhao, Min Zhang, Yuxin He, Wen Wang, Dan Li, Chuyu Chang, Zhaoxue Bao, Cuina Wang","doi":"10.3168/jds.2025-26298","DOIUrl":"https://doi.org/10.3168/jds.2025-26298","url":null,"abstract":"<p><p>In this study, glucono-δ-lactone-induced cold-set emulsion gels stabilized by whey protein (WPI) and pea protein (PPI) at various mass ratios were formulated, characterized, and applied. Compared with WPI-stabilized emulsion, zeta potential of emulsion decreased but droplet size, apparent viscosity, and modulus increased with increasing PPI. Differences in the properties of emulsions led to differences in the structure and properties of gels formed. Compared with emulsion gel formed by single PPI, the addition of WPI was found to improve the microstructure, water-holding capacity, rheological, and texture properties of emulsion gel, and the synergistic effect of WPI and PPI was observed at a mixing ratio of 75/25. In vitro digestion experiments revealed that all emulsion gels demonstrated comparable encapsulation, but adding PPI reduced stability and bio-accessibility, regardless of ratio. Data indicated that this method could produce a stable emulsion gel with properties modulated by adjusting the whey and pea protein ratio.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143961912","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":"Invited review: Future directions for cow-calf contact research and sustainable on-farm applications.","authors":"Laura Whalin, Kerstin Barth, Maja Bertelsen, Eddie A M Bokkers, Sabine Ferneborg, Marie J Haskell, Silvia Ivemeyer, Margit Bak Jensen, Juni Rosann Engelien Johanssen, Cecilie M Mejdell, Mikaela Mughal, Heather W Neave, Mette Vaarst, Ariette van Knegsel, Coenraad L van Zyl, Claire S Wegner, Julie Føske Johnsen","doi":"10.3168/jds.2024-26201","DOIUrl":"https://doi.org/10.3168/jds.2024-26201","url":null,"abstract":"<p><p>Prolonged cow-calf contact (CCC) is of growing importance to the dairy sector due to increasing societal interest, implementation of CCC on farms, and research efforts. Incorporating CCC into dairy systems may be a polarizing change for academics and farmers. However, by considering the challenges with curiosity, including those mutual to CCC and non-CCC systems, there may be an opportunity to collectively improve the management of dairy animals. The aim of this review was to describe current issues and constraints in CCC, propose opportunities to advance knowledge of CCC, and inspire forward-thinking questions for dairy systems. There are known challenges for CCC implementation, such as research reproducibility (e.g., suitable controls, validity types) and on-farm application (e.g., farmer perspectives, policies, and corporate standards). To facilitate practical solutions for farmers wanting to adopt CCC we need research describing the effects of CCC systems on animal health and behavior. Already researchers have begun to explore cow and calf performance and health, methods for decreasing stress at weaning and separation (e.g., duration of contact, gradual weaning), foster cows, and opportunities for positive animal welfare in CCC systems (e.g., affiliative and play behavior). However, because dairying takes place in a complex system, changes may affect different facets of the system's sustainability. We suggest that the development of CCC systems should happen in dialog with stakeholders. Cow-calf contact is an uncommon practice in dairy systems and exists in different contexts; thus, there are many questions to address before advice can be given to interested dairy stakeholders. Perhaps, these CCC-related questions are an invitation to contemplate how we want dairy systems to look like in 30 years.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143957770","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 controlled trial evaluating postpartum delayed milking strategy and oral calcium bolus administration on production and blood metabolites of Holstein cows.","authors":"H Beiranvand, A A Alamouti, M Yazdanyar, A Mohammadi-Sangcheshmeh, M R Bakhtiarizadeh, B Khorrami, F Ahmadi","doi":"10.3168/jds.2024-26031","DOIUrl":"https://doi.org/10.3168/jds.2024-26031","url":null,"abstract":"<p><p>Postpartum hypocalcemia has substantial economic impacts on dairy production systems. We hypothesized that the delayed milking immediately postpartum could enhance blood Ca status by limiting Ca secretion into milk. This, combined with oral Ca bolus administration, was hypothesized to attenuate Ca disturbances and improve the performance of cows in early lactation. Our objectives were to investigate the effects of delayed milking and Ca bolus supplementation on lactation performance and blood metabolites of dairy cows. A total of 699 Holstein cows (175 primiparous and 524 multiparous) were stratified by parity group and randomly assigned within each group to 6 treatments in a 2 × 3 factorial arrangement. Factor 1 was supplementation with 2 Ca boluses (BL; 31 g Ca/bolus), administered twice: once within 30 min and the second one 24 h after parturition, or no supplemental Ca (NBL). Factor 2 was the milking strategy whereby cows were milked 3 times daily (M0) or delayed-milked for 24 (M24) or 48 h (M48) after the colostrum harvest. This resulted in 6 treatment groups: M0-BL (n = 125), M24-BL (n = 118), M48-BL (n = 111), M0-NBL (n = 118), M24-NBL (n = 114), and M48-NBL (n = 113). Blood was collected immediately before calving and again at 1, 2, 3, 5, and 11 d postpartum. Milk production was recorded daily until 12 DIM, then monthly until 90 DIM. Generalized linear mixed models were used for the analysis of data. The BL supplementation did not affect milk yield or measured blood metabolites. In multiparous cows, blood Ca concentration at d 2 postcalving was 2.59 mM/L (95% CI = 2.49 to 2.69 mM/L) for M48 cows and 2.32 mM/L (95% CI = 2.26 to 2.48 mM/L) for M0 and M24 cows. Blood P concentration at d 2 postcalving was 2.33 mM/L (95% CI = 2.19 to 2.47 mM/L) for M48 cows, 1.81 mM/L (95% CI = 1.66 to 1.96 mM/L) for M24 cows, and 1.65 mM/L (95% CI = 1.49 to 1.81 mM/L) for M0 cows. At d 3 postcalving, blood P concentration was 2.01 mM/L (95% CI = 1.80 to 2.22 mM/L) for M48 cows, 1.78 mM/L (95% CI = 1.63 to 1.93 mM/L) for M24 cows, and 1.66 mM/L (95% CI = 1.50 to 1.82 mM/L) for M0 cows. Multiparous cows in the M48 group also had greater blood glucose at d 3 and lower BHB at d 2 after calving than M0-treated cows. In multiparous cows, the delayed milking strategy resulted in a lower daily milk yield from 3 to 12 DIM as compared with the M0 group. The 3 monthly test-day records remained unaffected across the experimental groups. Overall, delayed milking increased blood Ca and P and decreased BHB concentration in M48-treated cows. The effects of BL supplementation on production performance and blood metabolites and the potential synergy with delayed milking were not evident in this experiment.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143951375","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":"Evaluating the effects of zinc hydroxychloride on intestinal barrier permeability and biomarkers of inflammation and metabolism during and following heat stress.","authors":"S Rodriguez-Jimenez, E J Mayorga, M A Abeyta, B M Goetz, J Opgenorth, S K Kvidera, M M McCarthy, K E Griswold, L H Baumgard","doi":"10.3168/jds.2025-26261","DOIUrl":"https://doi.org/10.3168/jds.2025-26261","url":null,"abstract":"<p><p>Heat stress (HS) jeopardizes dairy cow productivity and health. Gastrointestinal tract (GIT) barrier dysfunction appears to be the etiological epicenter of HS-induced pathology. However, the physiology of recovery from HS has scarcely been studied in dairy cows. Thus, objectives were to evaluate the effects of supplemental zinc (Zn) hydroxychloride (HYD) on intestinal barrier permeability, metabolism, and inflammation during and following HS. Holstein cows (n = 24; 130 ± 34 DIM; parity 2 ± 0.5) were balanced by DIM and milk yield and assigned to 1 of 2 ad libitum-fed treatments: (1) control diet (CON; 75 mg/kg Zn from Zn sulfate; n = 12), or (2) HYD (75 mg/kg Zn from HYD; n = 12). Before study initiation, cows were fed their respective diets for 16 d. The trial consisted of 3 experimental periods (P), during which cows continued to receive their respective dietary treatment. Period 1 (5 d) served as the baseline for P2 (5 d), during which HS was artificially induced using electric heat blankets (EHB). During P3 (3 d), the EHB were removed, and cows were allowed to recover in thermoneutral conditions. In vivo total GIT permeability was evaluated on d 4 of P1, d 2 and 4 of P2, and d 2 of P3, using chromium (Cr)-EDTA. As expected, HS increased rectal and skin temperatures (+1.8 and +7.2°C, respectively) and respiration rate (+62 breaths per min) relative to baseline. Heat stress increased Cr appearance (indicative of increased permeability) on both d 2 and 4, and feeding HYD decreased blood Cr appearance on d 2 of P2, with the most pronounced decrease observed during h 1 (29%) relative to controls. Whereas haptoglobin (Hp) concentrations remained constant in CON cows relative to P1, they increased (77%) in HYD-fed cows from d 3 to 5 of HS. During HS recovery, plasma Hp levels remained elevated in HYD and markedly increased in CON (>6-fold) compared with d 5 of P2. Heat stress decreased DMI and milk yield (60% and 42%, respectively) relative to P1. During P3, overall Cr appearance was reduced (reflecting improved barrier function) compared with both P2 and 1. Dry matter intake gradually recovered in both treatments during HS recovery but was increased in HYD-fed cows (10%) relative to CON. Circulating nonesterified fatty acids and BHB progressively increased during HS in both treatments but tended to be lower in HYD from d 3 to 5 (28% and 14%, respectively) relative to CON, and the reducing effects of HYD on BHB continued during the early stage of HS recovery. In summary, HS-induced GIT hyperpermeability, caused inflammation, and altered metabolism; however, whereas inflammation persisted during HS recovery, Cr appearance decreased in P3 compared with P1 and 2. During the early stages of HS, supplementing HYD improved gut barrier function and modified both metabolism and inflammation, and increasing DMI during HS recovery.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143962747","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":"Invited review: Combined mitigation of methane and ammonia emissions from dairy barns through barn design, ventilation and air treatment systems.","authors":"A Kuipers, P Galama, S F Spoelstra, C J Wiering, P W G Groot Koerkamp","doi":"10.3168/jds.2024-26154","DOIUrl":"https://doi.org/10.3168/jds.2024-26154","url":null,"abstract":"<p><p>Removal of contaminants and gases from air in cattle housing systems makes a positive contribution to in-house air quality, thereby benefiting both animal and human welfare as well as reducing the environmental pressure from cattle. In this review, we aimed to combine knowledge of the capture of ammonia and methane from dairy cattle facilities by removing and oxidizing these gases from the ventilation air in one process. For cattle housing, several techniques are currently available and in various stages of development and application to capture ammonia from the air. A central component of these approaches is an air scrubber with acid to remove the ammonia from the ventilation air flow. In this review, we focused particularly on enteric methane from ruminants, because that represents the largest methane output on the dairy farm (∼80%) and remains the biggest challenge. We sought suitable physicochemical and microbiological methods and applications that absorb or oxidize methane from the air. Our literature review showed that the concentration of methane in modern, naturally ventilated, open cattle barns is relatively low (averages of 5 to 100 ppm), and at present, no cost- and climate-effective technology is available that can capture and oxidize methane at this low concentration. It was apparent that most techniques may only be able to capture or convert methane at concentrations above 500 ppm (and preferably >2000 ppm). The limiting factor is the diffusion speed of methane and the competition with other gases in case filtering or adsorption techniques are used. Therefore, we formulated the ventilation challenge, which refers to smart ventilation techniques that would allow capturing methane from the barn air at higher concentrations. In addition, technologies that have the capacity to capture ammonia and methane from the air are described separately and in combination. Then, inventive designs are presented to picture capturing of ammonia and methane in a one-process approach. Applying selected innovations, promising results are expected in lowering methane emissions from barns and storage areas (∼one-fourth reduction at the farm level). The development of more efficient adsorbents and bio and soil filters to optimize the process of adsorption and oxidation at low concentrate levels would enhance this reduction.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143951831","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":"Graduate Student Literature Review: Concepts and challenges of amino acid supply and nitrogen metabolism in dairy cattle.","authors":"M de Oliveira, C Costa, T Fernandes","doi":"10.3168/jds.2024-26136","DOIUrl":"https://doi.org/10.3168/jds.2024-26136","url":null,"abstract":"<p><p>Nitrogen utilization in dairy cows is crucial for maximizing production efficiency and minimizing environmental impacts. Ruminants possess a unique digestive system filled with microorganisms that work synergically to degrade feed particles and provide nutrients for both the microorganism and host metabolism. Dietary N, supplied as true protein and NPN, undergoes different degradation processes: a portion is degraded in the rumen, and another portion escapes ruminal degradation (i.e., RUP). Rumen-degraded protein is essential for microbial growth, contributing to the formation of microbial CP (MCP). Amino acids present in MCP and RUP that are digested and absorbed into the bloodstream and become available for animal metabolism (e.g., maintenance, growth, and production) constitute MP. Accurately assessing protein degradability and AA availability remains a challenge due to the limitations of current evaluation methods. In situ techniques are the most commonly used technique for this purpose, but they are not meant to predict MCP, RUP, and consequently the metabolizable AA supply of feed ingredients, which compromises diet formulation. Microbial CP growth is enhanced when both fermentable energy and N is available in the rumen. However, the extent of N recycling in sustaining microbial growth under low-protein diets is not adequately captured by MCP prediction models. Due to these limitations, several biases are added to protein models, resulting in protein overfeeding in an attempt to supply MP requirements and increasing both costs and N overload to the environment. Therefore, this review aims to synthesize fundamental information on the complex interplay of factors influencing ruminal protein degradation, MCP synthesis, AA supply, N metabolism, and N efficiency, and highlight the knowledge gaps that must be addressed to improve the accuracy of prediction models of AA supply in dairy cattle.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143952173","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":"Heat shock protein B1-mediated ferroptosis regulates mitochondrial dysfunction in adipose tissue of ketotic dairy cows.","authors":"Yunhui Fan, Li Ma, Xinyi Xu, Xinxin Fang, John Mauck, Juan J Loor, Xudong Sun, Hongdou Jia, Chuang Xu, Qiushi Xu","doi":"10.3168/jds.2025-26265","DOIUrl":"https://doi.org/10.3168/jds.2025-26265","url":null,"abstract":"<p><p>In the peripartal period, dairy cow adipose tissue undergo significant metabolic challenges, including oxidative stress and endoplasmic reticulum stress, which could be alleviated by inhibition of ferroptosis. Oxidative stress is often accompanied by mitochondrial damage. However, whether mitochondrial dysfunction occurs in the adipose tissue of ketotic cows are still unclear. Heat shock protein B1 (HSPB1), a key regulator of cellular redox homeostasis, is critical in managing oxidative stress and iron metabolism. Thus, this study aimed to investigate the role of HSPB1-mediated ferroptosis on mitochondrial dysfunction of adipocytes of ketotic dairy cows. We collected adipose tissue samples of clinical ketosis cows (n = 15) with a serum BHB concentration of 3.14 mM (interquartile range = 0.11) and healthy cows (n = 15) with a serum BHB concentration of 0.55 mM (interquartile range = 0.12). Compared with the healthy control group, the protein abundance of HSPB1, transferrin (TF), transferrin receptor 1 (TFR1), 6-transmembrane epithelial antigen of the prostate family member 3 (STEAP3), divalent metal transporter 1 (DMT1), and acyl-CoA synthetase 4 (ACSL4), as well as levels of reactive oxygen species, Fe²⁺, and total iron were greater in adipose tissue of ketotic cows. Ketotic cows exhibited lower ferroportin (FPN), solute carrier family 7 member 11 (SLC7A11), glutathione peroxidase 4 (GPX4), mitochondrial oxidative phosphorylation complexes I-V (CO I-V), peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α), mitofusin-2 (MFN2), nuclear respiratory factor 1 (NRF-1), and mitochondrial transcription factor A (Tfam) protein expression levels, along with lower ATP content compared with control cows. Epinephrine (EPI) treatment upregulated protein abundance of HSPB1 and induced ferroptosis and mitochondrial dysfunction in adipocytes. Inhibition of ferroptosis by pretreatment with ferrostatin-1 (Fer-1) attenuated the EPI-induced decrease in ATP content. Knockdown of HSPB1 by small interfering RNA (si-RNA) exacerbated the EPI-induced upregulation of TF, TFR1, STEAP3, and DMT1 expression and the downregulation of FPN protein expression levels. Furthermore, in the presence of EPI and HSPB1 si-RNA, Fer-1 abolished the regulatory role of HSPB1 on mitochondrial dysfunction, confirming that HSPB1 regulates bovine adipocyte mitochondrial dysfunction in a ferroptosis-dependent manner. Collectively, these data suggest that HSPB1-mediated ferroptosis is an important regulatory mechanism for mitochondrial dysfunction in adipocytes of peripartal dairy cows under negative energy balance.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143952205","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":"Incremental nicotinic acid supplementation to preweaning dairy calves: Effects on growth, blood metabolites, purine derivatives, and indirect rumen development.","authors":"T Islam, M A Rahman, L J Valentine, P S Erickson","doi":"10.3168/jds.2025-26270","DOIUrl":"https://doi.org/10.3168/jds.2025-26270","url":null,"abstract":"&lt;p&gt;&lt;p&gt;This experiment investigated nicotinic acid (NA) supplementation on growth, plasma glucose (GLU) and ketone concentrations, and urinary purine derivative (PD) excretion as indicators of ruminal development. Forty (22 male, 18 female) Holstein dairy calves, with initial body weight of 42.5 ± 5.60 kg (mean ± SD), were blocked by birth and randomly assigned to 1 of 4 levels of NA added to calf starter: 0 g/d (CON), 2 g/d (2NA), 4 g/d (4NA), and 6 g/d (6NA). Following parturition, calves received 4 L of colostrum (&gt;50 g IgG/L) within 24 h of birth and entered the study 1 d after birth until d 56. Calves had ad libitum access to water and starter (22.48 ± 0.83% CP). Calves were fed 3 L of milk replacer (MR; 24% protein, 17% fat) twice daily from d 2 to 42 (milk phase). Weaning started on d 43 to 49, with calves fed 3 L of MR every morning (weaning phase). Postweaning (d 50-56) calves were not fed MR. Body weight, withers and hip heights, length, and heart girth were measured on d 2 and weekly until d 56. Blood samples were taken at 24 h for IgG analysis and on d 2 of age and weekly until d 56 for GLU and ketone analyses. Urine samples were collected at 2 h and 4 h after feeding on d 56. Orthogonal polynomial contrasts were used to test the linear, quadratic, and cubic effects of incremental NA supply. Supplementing NA resulted in a linear reduction in starter intake and DMI during the milk phase and a tendency for a linear decrease after weaning. A tendency for improved feed efficiency (FE; ADG/DMI) was observed to increase linearly in the milk phase but remained unaffected thereafter. No treatment effects were observed for milk replacer intake or ADG during the milk and weaning phases; however, ADG exhibited a quadratic response in the postweaning phase. Water intake followed a quadratic response during the milk and weaning phases but was similar after weaning. Nicotinic acid intake displayed linear and cubic responses across all phases, with a treatment × week interaction. Weekly and final withers height and withers height gain demonstrated quadratic responses to increasing NA, with the greatest values in calves receiving 2NA. Similar patterns were seen in weekly hip height, final hip height, and final heart girth. Other skeletal measurements, including weekly length and weekly heart girth, were not affected by NA supplementation. Ketone concentrations showed no treatment effects except for a cubic tendency in final concentrations. Weekly GLU levels exhibited a negative linear tendency across treatments. Urinary creatinine and uric acid concentrations were unaffected. Allantoin and PD excretion increased linearly and showed a cubic tendency, with the greatest values at 2NA, indicating enhanced microbial protein synthesis. These findings suggest that 2NA supplementation improves FE, skeletal growth, and markers of rumen development (blood ketone and GLU concentrations). Greater doses of NA had no adverse effects, and calves receiving 2NA showed","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143954416","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 corn silage, alfalfa hay, and oat-vetch mixed silage combinations on milk production, rumen fermentation, and nutrient digestibility in high producing dairy cows.","authors":"Zhijie Luo, Alexander C O Evans, Dengpan Bu","doi":"10.3168/jds.2024-26096","DOIUrl":"https://doi.org/10.3168/jds.2024-26096","url":null,"abstract":"<p><p>The objective of this study was to explore the effects of corn silage, alfalfa hay, and oat-vetch mixed silage combinations on milk production, rumen fermentation, nutrient digestibility, and feeding cost in dairy cows. Nine multiparous Holstein dairy cows (DIM: 94.11 ± 9 d, milk yield: 41.0 ± 2.5 kg) were each fed 3 experimental diets in a replicated Latin square design. The experimental diets contained corn silage, alfalfa hay, and mixed silage in 3 different forage proportions (diet 1, 40:10:0; diet 2, 30:5:15, and diet 3, 20:0:30; DM basis). Cotton seed meal (CSM) or soybean meal (SBM) were used as the protein source to balance the CP content. The mixed silage was made from oats and vetch grown together in a 50:50 ratio, and all diets were formulated to contain 16% CP and 50:50 forage-to-concentrate ratio (DM basis). Cows fed diet 3 had a 9% reduction in DMI compared with diet 1. Associated with this reduction in DMI, cows fed diet 3 also had reduced yield of milk protein (22.0%), fat (15.7%), and lactose (18.5%) compared with cows fed diet 1. Characteristics of rumen fermentation were similar among diets; however, cows fed diet 3 had lower rumen fluid valerate and higher acetate: propionate ratios compared with diet 1. The N intake was not different among cows fed the 3 diets, but cows fed diet 3 excreted 0.2% less urinary N compared with diet 1. The combinations of corn silage and mixed silage reduced the cost of the diets (diet 1, $0.543; diet 2, $0.503; diet 3, $0.465/kg DM), and whereas milk production was reduced, the feed cost per milk yield was lowest for cows fed diet 3 ($0.404) and highest for cows fed diet 1 ($0.407). We conclude that cows fed diets with combinations of corn silage, alfalfa hay, and mixed silage, consumed less feed and produced less milk but also produced less urinary N and had a lower cost of feed for milk production than cows fed corn silage diets. This demonstrated that partial displacement of expensive corn silage, alfalfa hay, and SBM with mixed silage and CSM reduced costs, but due to the reduced DMI and milk yields, more research on these diets will be needed before they can be recommended as viable options to replace corn silage and SBM diets.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143958153","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}