JDS communications最新文献

{"title":"Exploring sustainability in dairy cattle breeding focusing on feed efficiency and methane emissions*","authors":"C.M. Richardson ,&nbsp;J.J. Crowley ,&nbsp;B. Gredler-Grandl ,&nbsp;P.R. Amer","doi":"10.3168/jdsc.2023-0461","DOIUrl":"10.3168/jdsc.2023-0461","url":null,"abstract":"<div><div>Reducing emissions is vital to improve sustainability, and industry leaders have set emission goals to reduce gross emissions, lower emissions intensity, or reach net zero. However, additional traits should also be measured and compared in terms of their impact on the broader definition of sustainability. In addition to environmental impact, a sustainable breeding objective must consider profit, animal welfare, farmer well-being, and social responsibility. Traits to be considered include direct emissions (e.g., nitrogen and methane), production efficiency (e.g., feed efficiency), health (e.g., calf and transition cow health), and welfare traits (e.g., polled). Many of these novel traits require labor- and cost-intensive phenotyping procedures. Consequently, this results in relatively modest data sets and estimated breeding values with limited reliability. Opportunities exist to overcome this limitation by developing cost-effective and easily quantifiable proxy traits and utilizing international collaboration to expand novel phenotype reference populations. Furthermore, noneconomic values can be estimated to quantify the impact of a trait on societal perspective (e.g., farmer preference) or environmental impact (methane emissions), and combined with economic weights to calculate aggregate weights for each trait. Although validation techniques are still uncertain, the United Nations Sustainable Development Goals may be applied to determine the improvement in sustainability due to genetic selection. This approach provides the flexibility to accommodate diverse sustainability perspectives, encompassing the disparities between developed and developing countries. Currently, the number and quality of relevant phenotypes are the main limiting factor. However, as confidence grows in the opportunity to improve sustainability through genetic selection, substantial new investment will be required in both refining phenotyping methodologies and conceptualizing novel breeding designs.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"5 6","pages":"Pages 751-755"},"PeriodicalIF":0.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140404599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variation in partial direct costs of dry cow therapy on 37 large dairy herds","authors":"J. Leite de Campos ,&nbsp;A. Kates ,&nbsp;A. Steinberger ,&nbsp;A. Sethi ,&nbsp;G. Suen ,&nbsp;John Shutske ,&nbsp;N. Safdar ,&nbsp;Tony Goldberg ,&nbsp;P.L. Ruegg","doi":"10.3168/jdsc.2024-0568","DOIUrl":"10.3168/jdsc.2024-0568","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The objective of this observational study was to estimate partial direct costs of dry cow antibiotic therapy (DCT) protocols used on 37 large dairy herds in Wisconsin and to estimate the potential monetary savings and reduction in antimicrobial usage (AMU) if selective DCT was used. Partial direct costs of DCT were calculated using costs of intramammary (IMM) antimicrobials and teat sealants. Data were retrospectively collected on 37 large dairy farms for a period of 1 yr and included the total number of cows dried off, types of IMM antimicrobial used, and product prices (obtained from farm invoices). A single farm visit was performed to verify data. Clinical mastitis (CM) and SCC history across lactation were used as the criteria to identify cows eligible to receive only teat sealants (no antibiotic DCT) based on adoption of a hypothetical selective DCT program. Descriptive statistics were performed using PROC MEANS to summarize continuous herd and cow characteristics. Differences in costs among IMM antibiotic products and eligibility to not receive antibiotics at dry-off by parity were analyzed using ANOVA. Differences in milk yield at the last test-day and DIM at dry-off based on eligibility for selective DCT were analyzed using PROC MIXED. A total of 35,691 cows were dried off across all herds (n = 37) and most of the herds used IMM antibiotic DCT at dry-off in most of the cows. Teat sealant was used as part of the dry-off protocol in all but 3 herds. Of the enrolled farms, 30 used blanket antibiotic DCT in all quarters of all cows and 7 herds used selective DCT with no administration of antibiotics given to 0.8% to 58% of the dry cows within the herd. Across all farms, the average cost of products given per dried cow was $19.57 ± 0.64 (mean ± SE) and ranged from $8.72 to $24.04. As expected, the cost per dried cow was greater ($23.45 ± $0.38) in herds that used higher cost IMM antibiotics as compared with herds that used lower cost IMM antibiotics ($16.64 ± $0.40). When using an algorithm based on udder health records to hypothetically select cows that would be eligible to receive teat sealants only (no antibiotic DCT), eligibility ranged from 27.3% to 93.3% within-herds and varied by parity, milk yield at last test-day, and DIM at dry-off. If a selective DCT program based on udder health records was used, an overall reduction of $5.37 (27% of total costs) per dry cow would be expected. Likewise, adoption of selective DCT based on udder health records would reduce AMU at dry-off by approximately 51%. However, neither of these estimates included potential adverse health complications (such as increased CM) that can occur if selective DCT programs are not effectively performed. Variations in partial direct costs at dry-off were observed among herds based on treatment protocols. In herds that have good udder health management and contagious mastitis pathogens controlled, adoption of selective DCT based on SCC and history of CM can red","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"5 6","pages":"Pages 639-643"},"PeriodicalIF":0.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141029201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of an in vitro model to study CD4+ T cell metabolism in dairy cows","authors":"U. Arshad,&nbsp;M. Cid de la Paz,&nbsp;H.M. White,&nbsp;L.R. Cangiano","doi":"10.3168/jdsc.2024-0565","DOIUrl":"10.3168/jdsc.2024-0565","url":null,"abstract":"<div><div>Dairy cows are susceptible to several health disorders throughout their lactation. Objectives were to characterize an in vitro model to study bioenergetic measures in CD4⁺ T lymphocytes in dairy cows. Twenty-four healthy mid-lactation multiparous Holstein dairy cows were enrolled at a mean (±SD) of 234 ± 22 DIM. Cows were blocked according to DIM and blood was collected to isolate peripheral blood mononuclear cells followed by magnetic separation of CD4⁺ T lymphocytes using bovine-specific monoclonal antibodies. The isolated CD4⁺ T lymphocytes from each cow were split into 2 tubes and randomly assigned to incubate in an assay medium as control (CON) or with a combination of phorbol myristate acetate and ionomycin (PMA+IMY) to evaluate metabolic function under a resting and activated state. Mitochondrial and glycolytic functional kinetics were recorded in CD4⁺ T lymphocytes based on real-time measurement of oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) under basal conditions and in response to complex V inhibitor (oligomycin), a protonophore uncoupler (BAM 15), and complex I and complex III inhibitors (rotenone and antimycin A). The mean (±SD) viability and purity of CD4⁺ T lymphocytes was 92.5 ± 2.9% and 95.2 ± 2.9%, respectively. The basal OCR in CD4⁺ T lymphocytes treated with PMA+IMY was greater than CON; nevertheless, the maximal respiration rate (CON = 58.0 vs. PMA+IMY = 47.3 ± 5.7 pmol/min) and sparing respiratory capacity rate (CON = 42.0 vs. PMA+IMY = 28.7 ± 4.2 pmol/min) were decreased in activated CD4⁺ T lymphocytes. The ECAR in CD4⁺ T lymphocytes increased progressively over time in PMA+IMY compared with CON, which indicated an increase in aerobic glycolysis in PMA+IMY compared with CON (CON = 46.9 vs. PMA+IMY = 86.4 ± 7.0 pmol/min). Activated CD4⁺ T lymphocytes exhibit a metabolic switch from oxidative phosphorylation to aerobic glycolysis, which may support rapid cell proliferation. The results observed in this experiment demonstrate the sensitivity of the technique to detect changes in metabolic function under different cellular conditions, providing a robust framework to study immuno-metabolism in dairy cattle.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"5 6","pages":"Pages 740-744"},"PeriodicalIF":0.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141041182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the dynamics of mastitis in milk yield: Decoding onset and recovery patterns in response to mastitis occurrence","authors":"A.L.L. Sguizzato ,&nbsp;T.E. da Silva ,&nbsp;J.C.C. Chagas ,&nbsp;A.M. Argüelo ,&nbsp;N.M. Gonçalves ,&nbsp;M.I. Marcondes","doi":"10.3168/jdsc.2024-0579","DOIUrl":"10.3168/jdsc.2024-0579","url":null,"abstract":"<div><div>No recent study has attempted to model daily milk losses before and after mastitis onset and the moment when it begins. Thus, we aimed to describe the impact of mastitis on milk production based on mastitis level and moment of occurrence. We used data from 11 dairy farms, and the dataset consisted of 885,759 daily individual milk test records from 3,508 cows in different lactations, with an average milk yield (MY) from January 2017 to December 2022. We modeled the impact of mastitis severity (i.e., 1 [mild] and 2 [severe]) based on the drop and recovery of MY following 3 steps. First, we removed milk recorded on the day of diagnosis of mastitis from the dataset and fitted a Wood's curve for each cow and parity. Second, we returned the mastitis data to the dataset and estimated the residual milk loss due to mastitis from 15 d before to 30 d after the mastitis event. Third, we used generalized additive mixed effect models to estimate the residual milk loss, including farm as a random effect. In addition to the random effect of the farm, we also included the predicted milk yield (by Wood's curve) over the influence of mastitis, the day effect before and after mastitis incidence, and the interaction between the predicted value of mastitis and days. On average, mastitis level 2 resulted in a more severe MY drop in all represented stages of lactation (80, 170, and 260 DIM), suggesting a higher loss close to the lactation peak, approximately 130 kg more than mastitis level 1. Moreover, the occurrence of mastitis case level 1 during the early phase of lactation (DIM 80) can cause an average milk loss of 158 L and mastitis level 2, an average loss of 288 L. The estimations suggest that milk drop occurs 14 to 4 d before mastitis onset and can last until 15 to 25 d from the diagnosis, which would be the necessary time for a cow to re-establish their predicted MY. Therefore, our study brings new perspectives to investigate MY drop and recovery due to mastitis infections and how much mastitis can deplete and impair milk production.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"5 6","pages":"Pages 669-673"},"PeriodicalIF":0.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141710695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hemoconcentration differs in neonatal dairy calves: Considerations for assessment of transfer of passive immunity","authors":"T.A. Westhoff ,&nbsp;R.A. Molano ,&nbsp;M.E. Van Amburgh ,&nbsp;S. Mann","doi":"10.3168/jdsc.2024-0570","DOIUrl":"10.3168/jdsc.2024-0570","url":null,"abstract":"<div><div>Assessing transfer of passive immunity (TPI) is a critical management strategy to evaluate colostrum management and feeding; however, variability in hemoconcentration or serum or plasma volume in calves might influence TPI assessment. The objectives of this study were to (1) describe the variability in hemoconcentration as well as TPI in Holstein calves in New York State and (2) describe the effect of adjusting total protein (TP) for the degree of hemoconcentration by applying a sample average proportion of plasma in blood (PP) on TPI assessment. Records of TP and PP from 703 Holstein calves 1 to 9 d of age from 19 commercial dairy farms were analyzed. The PP was determined by centrifugation of microhematocrit tubes and serum and plasma TP was determined by digital refractometry. Transfer of passive immunity was categorized using unadjusted TP (uTP) as excellent = ≥6.2, good = 5.8–6.1, fair = 5.1–5.7, and poor &lt;5.1 g/dL. Individual calf TP concentrations were adjusted to the sample average PP and TPI categories were reassessed using the adjusted TP value (aTP). The sample mean ± SD (range) PP was 68.8% ± 5.8% (50.5% to 86.0%). The PP was lower on d 1 compared with d 7 of age. Using uTP to categorize TPI, 22 (3.1%) calves had poor, 113 (16.2%) calves had fair, 164 (23.6%) calves had good, and 397 (57.1%) calves had excellent TPI, respectively. After adjusting TP for hemoconcentration, TPI determined using aTP resulted in 52 (7.5%, +4.4 percentage points) calves in poor, 137 (19.7%, +3.5 percentage points) calves in fair, 122 (17.5%, −6.1 percentage points) calves in good, and 385 (55.3%, −1.8 percentage points) calves in excellent. The mean (range) proportion of calves with TPI determined using uTP by farm was 3.9% (0% to 16%) for poor, 19.0% (2% to 36%) for fair, 25.3% (10% to 42%) for good, 51.8% (26% to 83%) for excellent. When categorized using aTP, the proportion of calves by farm was 8.1% (0% to 21%) in poor, 20.5% (8% to 42%) in fair, 19.1% (6% to 33%) in good, and 52.4% (27% to 83%) in excellent TPI. In conclusion, PP was variable in calves during the time of TPI assessment and this variability should be considered when assessing TPI at the calf- or herd level.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"5 6","pages":"Pages 713-718"},"PeriodicalIF":0.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141038391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Supplementing Silicoglycidol for the reduction of aflatoxin M1 in milk and biomarkers of liver dysfunction in dairy cows","authors":"E.H. Branstad-Spates ,&nbsp;C.S. McCarthy ,&nbsp;B.C. Dooley ,&nbsp;L.E. King ,&nbsp;E.L. Bowers ,&nbsp;A. Tesouro ,&nbsp;J. Borrell ,&nbsp;D. Díez ,&nbsp;G.E. Rottinghaus ,&nbsp;L.H. Baumgard","doi":"10.3168/jdsc.2023-0538","DOIUrl":"10.3168/jdsc.2023-0538","url":null,"abstract":"<div><div>Aflatoxin M₁ (AFM₁) is a pathogenic metabolite transferred from feed into milk from aflatoxin (AF) B₁, B₂, G₁, and G₂; thus, it poses a human health risk. Therefore, effective mitigation strategies are needed to reduce animal and human exposure to AF. Study objectives were to evaluate a dietary adsorbent (Silicoglycidol, ATX) as a sequestering agent in AF-contaminated feed and to broadly examine how AF affects liver function and the immune system. Primiparous Holstein cows (n = 12; 279 ± 88 DIM and 675 ± 19 kg BW) were used in a replicated 3 × 3 Latin square design with 21-d periods in which d 1 to 14 were considered adaptation, and data collected on d 15 to 21 were used for analysis. Treatments were (1) control (CON) consisting of a basal diet, (2) AF diet consisting of CON+AF challenge (100 µg of AFB₁/kg DMI), and (3) AF+ATX supplemented at 0.10% of dietary DMI. Feed intake and milk yield were recorded daily, fecal samples were collected on d 20 of each period, blood and urine samples were collected on d 21 of each period, and milk samples were collected on the last 2 d of each period. Data were analyzed using the MIXED procedure of SAS (SAS Institute Inc.). Milk yield and DMI were unaffected by treatment (26.8 ± 1.3 kg/d and 24.0 ± 0.9 kg/d, respectively). Similarly, neither milk composition nor DMI digestibility were affected by treatment. No AFM₁ was detected in CON cow milk or urine. Supplementing ATX reduced AFM₁ in milk (1.57 vs. 1.14 ± 0.1 µg/L for AF and AF+ATX, respectively) and urine (9.9 vs. 5.6 ± 1.1 µg/L for AF and AF+ATX, respectively). Consuming AF did not affect biomarkers of liver health or immune activation including alanine aminotransferase, aspartate aminotransferase, gamma glutamyltransferase, haptoglobin, and IgG. In summary, feeding ATX reduced the absorption and transfer of dietary AF to milk and urine.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"5 6","pages":"Pages 684-689"},"PeriodicalIF":0.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140400598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of lactose content in milk replacer on apparent digestibility, growth, liver messenger RNA expression, and blood parameters related to metabolism of dairy calves","authors":"R. Fukumori ,&nbsp;M. Hirose ,&nbsp;I. Norimura ,&nbsp;T. Nakayama ,&nbsp;K. Shimada ,&nbsp;H. Mineo ,&nbsp;M.A. Steele ,&nbsp;S. Gondaira ,&nbsp;H. Higuchi ,&nbsp;K. Chisato ,&nbsp;S. Oikawa ,&nbsp;K. Izumi","doi":"10.3168/jdsc.2023-0528","DOIUrl":"10.3168/jdsc.2023-0528","url":null,"abstract":"<div><div>Even with the same energy supply, differences in energy sources may affect calf growth and metabolism. In this study, we evaluated the effects of feeding 3 different milk replacers (MR) with different lactose supplies under isoenergetic conditions on calf digestibility, growth, and metabolism-related markers. Fifteen Holstein bull calves were randomly assigned to one of 3 MR feeding treatments: low lactose (L: 38%), medium lactose (M: 41%), or high lactose (H: 46%). After birth, calves were provided colostrum, and treatment MR were fed from 1 d of age and gradually increased to a maximum feeding rate at 20 d of age (L: 1.16 kg/d, M: 1.21 kg/d, H: 1.26 kg/d DM) without feeding solid feeds during the experimental period. Blood samples were temporarily collected weekly to assess blood concentrations of metabolites and hormones. From 30 to 36 d of age, the calves were euthanized and liver samples were collected to determine growth-related mRNA expression. The L calves showed a greater body length than H calves and the highest growth hormone receptor (GHR) mRNA expression. Plasma concentrations of total cholesterol, urea nitrogen, total protein, albumin, insulin, and IGF-1 were not different, but plasma concentrations of triglycerides were greater in order H, M, and L. These results showed that the difference in lactose content in the MR affected calf metabolism, and the L-MR was suggested to be more likely to enhance growth into the peripheral tissues.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"5 6","pages":"Pages 719-724"},"PeriodicalIF":0.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141027119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Apparent prevalence of transplacental transmission of hemotropic mycoplasmas in Holstein dairy calves","authors":"L. de Souza Ferreira ,&nbsp;S. Bolin ,&nbsp;A. Abuelo ,&nbsp;B. Norby ,&nbsp;P.L. Ruegg","doi":"10.3168/jdsc.2023-0518","DOIUrl":"10.3168/jdsc.2023-0518","url":null,"abstract":"<div><div>Hemotropic mycoplasmas are unculturable bacteria that infect the surface of red blood cells of several mammalian species including cattle. The importance of hemoplasmas in cattle remains unclear and limited information is available about biological routes of transmission. The objective of this cross-sectional study was to determine the prevalence of transplacental transmission of hemoplasmas and to determine if colostrum of infected cows contained DNA from hemoplasma organisms. In March 2023, researchers collected colostrum and peripheral blood samples from 39 dairy cows and their newborn calves (before ingestion of colostrum) at a single dairy farm in Michigan. Detection of <em>Mycoplasma wenyonii</em> and <em>Candidatus Mycoplasma haemobos</em> was performed using real-time PCR. The apparent prevalence of hemoplasma infection in dams was 100%, with 84.6% (33/39) co-infected with both <em>M. wenyonii</em> and <em>C. M. haemobos</em>, whereas the remaining 15.3% (6/39) were infected solely with <em>C. M. haemobos</em>. The prevalence of newborn calves infected with <em>C. M. haemobos</em> was 10.2% (4/39), and none were infected with <em>M. wenyonii</em>. No colostrum samples tested positive for either <em>M. wenyonii</em> or <em>C. M. haemobos</em>. This is the first report of vertical transmission of hemoplasmas in a dairy herd located in the United States. However, the relatively low prevalence of infected newborn calves suggests that transplacental transmission is not the predominant pathway of infection. The absence of positive tests in colostrum may indicate ingestion of colostrum contaminated with hemoplasmas is not common. The clinical importance of fetal infection remains known.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"5 6","pages":"Pages 587-591"},"PeriodicalIF":0.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Galacto-oligosaccharide production by Lactobacillus delbrueckii ssp. bulgaricus whole cells and lysates","authors":"Giselle K.P. Guron,&nbsp;Arland T. Hotchkiss Jr.,&nbsp;John A. Renye Jr.,&nbsp;Adam M. Oest,&nbsp;Michael J. McAnulty","doi":"10.3168/jdsc.2024-0580","DOIUrl":"10.3168/jdsc.2024-0580","url":null,"abstract":"<div><div>β-Galactosidase is currently applied in foods for reduction of lactose but can also be used for its transgalactosylation activity to synthesize galacto-oligosaccharides (GOS) as prebiotics. The ability of GRAS-status <em>Lactobacillus delbrueckii</em> strains to exhibit such activities would benefit consumers given their extensive history with dairy products. The objective of this study was to characterize the production of GOS in 6 <em>L. delbrueckii</em> strains for their ability to synthesize GOS in 50 m<em>M</em> sodium phosphate (pH 6.5) with a high lactose concentration of 788.8 m<em>M</em> at 50°C. <em>Lactobacillus delbrueckii</em> ssp. <em>bulgaricus</em> B548, LB11, and YB1 lysates released the most glucose at 112.8 ± 6.2 m<em>M</em>, 150.4 ± 11.7 m<em>M</em>, and 190.2 ± 12.2 m<em>M</em>, respectively. However, the ratio of free glucose to galactose released by B548 lysate (1.4 ± 0.3) was lower than that of LB11 (2.8 ± 0.6) and YB1 (2.5 ± 0.6) lysates, so the latter strains were screened at different initial lactose concentrations. The GOS yield from YB1 was not dependent on initial lactose concentration, averaging 54.3 ± 0.6% across starting lactose concentrations. However, optimal LB11 transgalatosylation had an initial concentration of 394.4 m<em>M</em> lactose instead of 788.8 m<em>M</em>, resulting in a GOS yield of 56.8% instead of 47.3%. In all cases for LB11, the lysates had greater free glucose, galactose, and GOS yield than whole cells. The ability of 2 <em>Lactobacillus delbrueckii</em> ssp. <em>bulgaricus</em> strains to produce GOS from common lactose-containing ingredients can have a range of applications in the dairy industry.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"5 6","pages":"Pages 522-527"},"PeriodicalIF":0.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141406502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of radial immunodiffusion, turbidimetric immunoassay, and Brix refractometry for determining bovine colostrum quality","authors":"T.A. Westhoff,&nbsp;E.L. Behling-Kelly,&nbsp;S. Mann","doi":"10.3168/jdsc.2024-0604","DOIUrl":"10.3168/jdsc.2024-0604","url":null,"abstract":"<div><div>Determining the concentration of IgG in colostrum is critical for assessment of colostrum quality. On-farm use of a Brix refractometer to estimate colostrum IgG concentration is widespread, whereas radial immunodiffusion (RID) is the laboratory reference method. Turbidimetric immunoassay (TIA) might offer an alternative method to quantify IgG in colostrum, but the agreement with RID, as well as critical thresholds to determine high-quality colostrum, remain uncertain. The objective of this study was to determine the level of agreement between RID, Brix %, and TIA for evaluation of colostrum quality. Composite colostrum samples (n = 58) from Holstein cows were evaluated using a digital Brix refractometer at the time of collection and stored at −20°C until analysis. The concentration of IgG was determined using RID and TIA. Data were analyzed using Passing-Bablok regression and Bland-Altman plots. Critical thresholds for TIA and Brix measurements to identify colostrum with an IgG concentration ≥50 and ≥100 g/L based on the reference method were determined using logistic regression and receiver operating characteristic curves. Results revealed that both TIA (Kendall's τ = 0.91) and Brix % (τ = 0.78) had a strong correlation with RID. Passing-Bablok regression identified a systematic (6.91 [4.33 to 8.98] g/L) and proportional (0.69 [0.67 to 0.72] g/L) bias between RID and TIA. The optimum thresholds to identify samples with an IgG concentration ≥50 and ≥100 g/L were 40.6 g/L (area under the curve [AUC]: 1.0; sensitivity (Se): 100; specificity [Sp]: 100) and 85.8 g/L (AUC: 0.99; Se: 96.6; Sp: 96.6) for TIA and 18.4% (AUC: 1.0; Se: 100; Sp: 100) and 25.8% (AUC: 0.99; Se: 82.8; Sp: 93.1) for Brix %, respectively. Using the identified thresholds, our results show that both Brix and TIA were highly accurate for identifying high-quality colostrum, but because of a proportional bias, direct comparison of IgG concentration results obtained by RID and TIA are cautioned.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"5 6","pages":"Pages 679-683"},"PeriodicalIF":0.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141715949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}