C.I.V. Manzanilla-Pech , A.E. van Breukelen , R.F. Veerkamp , Y. de Haas , M. van Pelt , B. Gredler-Grandl
<div><div>One of the most promising strategies to permanently reduce methane emissions in dairy cattle is through genomic selection, where the primary goal is to identify and selectively breed low-emitting ruminants. An important step is to define which trait definition to use. Several methane phenotypes have been proposed in recent years. When measuring methane using breath analyzers (sniffers), 2 commonly used phenotypes are methane concentration (CH<sub>4</sub>c; ppm) and methane production (CH<sub>4</sub>p; g/d). However, different definitions exist for both phenotypes. For example, for CH<sub>4</sub>c, the average per visit is commonly used, but other phenotypes involving the identification of eructation peaks have been suggested. Several formulas are available to calculate CH<sub>4</sub>p, using CH<sub>4</sub>c or the ratio between CH<sub>4</sub>c and CO<sub>2</sub> concentrations as input, together with other production traits. Additionally, methane intensity (MeI), another phenotype of interest, is the amount of methane produced per milk unit (kg). Therefore, the aims of this study were (1) to estimate genetic parameters for 11 distinct phenotypes, including 3 CH<sub>4</sub>c definitions, carbon dioxide concentration per visit (CO<sub>2</sub>c), the ratio between CH<sub>4</sub>c and CO<sub>2</sub>c, 5 phenotypes for CH<sub>4</sub>p based on different formulas (Madsen, Chagunda, 2 of Kjeldsen, and IPCC Tier2 as a benchmark), and MeI; and (2) to estimate genetic correlations between these methane phenotypes and milk yield (MY) and BW. A total of 149,726 sniffer (CH<sub>4</sub>c and CO<sub>2</sub>c) records were available from 7,600 Dutch Holstein cows measured between 2019 and 2024 on 68 farms. Data were analyzed with an animal repeatability model with fixed effects, including herd-year-season, week of lactation, and lactation number with age of cow at calving nested. Estimated heritability values ranged from 0.16 to 0.30 for CH<sub>4</sub>c phenotypes, with the number of eructation peaks having the highest heritability. For CH<sub>4</sub>p, heritabilities ranged from 0.03 to 0.27, with Tier2 having the highest value. Heritabilities for the CH<sub>4</sub>c/CO<sub>2</sub>c ratio and CO<sub>2</sub>c were 0.08 and 0.13, respectively. Genetic correlations between CH<sub>4</sub>c phenotypes were moderate to highly positive, ranging between 0.49 and 0.85. Likewise, highly positive genetic correlations (between 0.89 and 1) were estimated for CH<sub>4</sub>p phenotypes, except for Tier2, which presented correlations between 0.04 and 0.37 with the other CH<sub>4</sub>p phenotypes. Average CH<sub>4</sub>c (avg) per visit and sum of maximum peaks of CH<sub>4</sub>c (speaks) had moderate to high positive correlations (0.36–0.95) with the majority of the CH<sub>4</sub>p phenotypes (except Tier2). Methane intensity had moderate to high positive genetic correlations (0.38 to 0.80) with the majority of the phenotypes except for Kjeldsen2 (0.03) and Tier2 (
{"title":"Exploring different definitions of methane phenotypes in Dutch Holstein cattle","authors":"C.I.V. Manzanilla-Pech , A.E. van Breukelen , R.F. Veerkamp , Y. de Haas , M. van Pelt , B. Gredler-Grandl","doi":"10.3168/jdsc.2025-0845","DOIUrl":"10.3168/jdsc.2025-0845","url":null,"abstract":"<div><div>One of the most promising strategies to permanently reduce methane emissions in dairy cattle is through genomic selection, where the primary goal is to identify and selectively breed low-emitting ruminants. An important step is to define which trait definition to use. Several methane phenotypes have been proposed in recent years. When measuring methane using breath analyzers (sniffers), 2 commonly used phenotypes are methane concentration (CH<sub>4</sub>c; ppm) and methane production (CH<sub>4</sub>p; g/d). However, different definitions exist for both phenotypes. For example, for CH<sub>4</sub>c, the average per visit is commonly used, but other phenotypes involving the identification of eructation peaks have been suggested. Several formulas are available to calculate CH<sub>4</sub>p, using CH<sub>4</sub>c or the ratio between CH<sub>4</sub>c and CO<sub>2</sub> concentrations as input, together with other production traits. Additionally, methane intensity (MeI), another phenotype of interest, is the amount of methane produced per milk unit (kg). Therefore, the aims of this study were (1) to estimate genetic parameters for 11 distinct phenotypes, including 3 CH<sub>4</sub>c definitions, carbon dioxide concentration per visit (CO<sub>2</sub>c), the ratio between CH<sub>4</sub>c and CO<sub>2</sub>c, 5 phenotypes for CH<sub>4</sub>p based on different formulas (Madsen, Chagunda, 2 of Kjeldsen, and IPCC Tier2 as a benchmark), and MeI; and (2) to estimate genetic correlations between these methane phenotypes and milk yield (MY) and BW. A total of 149,726 sniffer (CH<sub>4</sub>c and CO<sub>2</sub>c) records were available from 7,600 Dutch Holstein cows measured between 2019 and 2024 on 68 farms. Data were analyzed with an animal repeatability model with fixed effects, including herd-year-season, week of lactation, and lactation number with age of cow at calving nested. Estimated heritability values ranged from 0.16 to 0.30 for CH<sub>4</sub>c phenotypes, with the number of eructation peaks having the highest heritability. For CH<sub>4</sub>p, heritabilities ranged from 0.03 to 0.27, with Tier2 having the highest value. Heritabilities for the CH<sub>4</sub>c/CO<sub>2</sub>c ratio and CO<sub>2</sub>c were 0.08 and 0.13, respectively. Genetic correlations between CH<sub>4</sub>c phenotypes were moderate to highly positive, ranging between 0.49 and 0.85. Likewise, highly positive genetic correlations (between 0.89 and 1) were estimated for CH<sub>4</sub>p phenotypes, except for Tier2, which presented correlations between 0.04 and 0.37 with the other CH<sub>4</sub>p phenotypes. Average CH<sub>4</sub>c (avg) per visit and sum of maximum peaks of CH<sub>4</sub>c (speaks) had moderate to high positive correlations (0.36–0.95) with the majority of the CH<sub>4</sub>p phenotypes (except Tier2). Methane intensity had moderate to high positive genetic correlations (0.38 to 0.80) with the majority of the phenotypes except for Kjeldsen2 (0.03) and Tier2 (","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"7 1","pages":"Pages 50-55"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M.A. Pérez-Cabal , I. Cervantes , J.P. Gutiérrez , N. Charfeddine
Ketosis is the most prevalent metabolic disorder in dairy herds, and reducing its incidence is a key objective in most dairy cattle breeding programs. Whereas clinical ketosis is rarely recorded, milk β-hydroxybutyrate (mBHB) concentration is routinely available through milk recording systems and can serve as a reliable indicator of subclinical ketosis. The objective of this study was to evaluate mBHB as a metabolic disease trait for inclusion in the Spanish Holstein breeding program, aiming to identify animals less susceptible to ketosis by exploring alternative trait definitions for future genetic evaluations. Five mBHB traits were studied, one for each of the first 5 lactations. Two datasets were compared to assess the benefit of using either all available test-day records or only the first test-day available within the initial 68 DIM, which reduced the data volume to 49% of total records. The statistical model included fixed effects of lactation-age at calving, month of calving, and DIM as a linear covariate. Random effects included herd-year of calving, the additive genetic effect, and the permanent environmental effect of repeated measures (test-day records) within lactation. Heritability estimates for mBHB traits ranged from 0.04 to 0.12, with consistent results across both datasets. Genetic correlations among lactations were high (0.67–0.98), 2 test-day records yielded better predictions, mean EBV reliabilities for sires ranged from 12% to 42%, and moderate rank correlations (0.12–0.52) among sires were observed. These findings suggest that using 2 test-day records and data from the first 3 lactations may be sufficient for incorporating mBHB as an indicator trait of subclinical ketosis in the Spanish Holstein breeding program.
{"title":"Genetic parameters of milk β-hydroxybutyrate as an indicator of metabolic diseases in Spanish dairy cows","authors":"M.A. Pérez-Cabal , I. Cervantes , J.P. Gutiérrez , N. Charfeddine","doi":"10.3168/jdsc.2025-0841","DOIUrl":"10.3168/jdsc.2025-0841","url":null,"abstract":"<div><div>Ketosis is the most prevalent metabolic disorder in dairy herds, and reducing its incidence is a key objective in most dairy cattle breeding programs. Whereas clinical ketosis is rarely recorded, milk β-hydroxybutyrate (mBHB) concentration is routinely available through milk recording systems and can serve as a reliable indicator of subclinical ketosis. The objective of this study was to evaluate mBHB as a metabolic disease trait for inclusion in the Spanish Holstein breeding program, aiming to identify animals less susceptible to ketosis by exploring alternative trait definitions for future genetic evaluations. Five mBHB traits were studied, one for each of the first 5 lactations. Two datasets were compared to assess the benefit of using either all available test-day records or only the first test-day available within the initial 68 DIM, which reduced the data volume to 49% of total records. The statistical model included fixed effects of lactation-age at calving, month of calving, and DIM as a linear covariate. Random effects included herd-year of calving, the additive genetic effect, and the permanent environmental effect of repeated measures (test-day records) within lactation. Heritability estimates for mBHB traits ranged from 0.04 to 0.12, with consistent results across both datasets. Genetic correlations among lactations were high (0.67–0.98), 2 test-day records yielded better predictions, mean EBV reliabilities for sires ranged from 12% to 42%, and moderate rank correlations (0.12–0.52) among sires were observed. These findings suggest that using 2 test-day records and data from the first 3 lactations may be sufficient for incorporating mBHB as an indicator trait of subclinical ketosis in the Spanish Holstein breeding program.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"7 1","pages":"Pages 46-49"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Luis A. Ibarra-Sánchez , Alan L. Olvera-Aguilar , Kruskaia K. Caltzontzin-Fernández, José A. Cabrera-Luna
Small family dairy farmers are a type of production system in Mexico characterized by family-owned farms where family members are dedicated to the production of milk and dairy products such as cheese. Artisanal cheeses made by small family cheesemakers are typically made with raw milk, raising concern for presence of spoilage and pathogenic microorganisms. Although small family cheesemakers have traditional intergenerational knowledge of cheese manufacturing, their knowledge of hygienic practices may be limited. This mini-review provides an overview of the microbial quality of artisanal cheeses made by small family cheesemakers in Mexico and their manufacturing practices as factors affecting cheese microbial contamination.
{"title":"Small family cheesemaking in Mexico: Microbial quality and good manufacturing practices","authors":"Luis A. Ibarra-Sánchez , Alan L. Olvera-Aguilar , Kruskaia K. Caltzontzin-Fernández, José A. Cabrera-Luna","doi":"10.3168/jdsc.2025-0801","DOIUrl":"10.3168/jdsc.2025-0801","url":null,"abstract":"<div><div>Small family dairy farmers are a type of production system in Mexico characterized by family-owned farms where family members are dedicated to the production of milk and dairy products such as cheese. Artisanal cheeses made by small family cheesemakers are typically made with raw milk, raising concern for presence of spoilage and pathogenic microorganisms. Although small family cheesemakers have traditional intergenerational knowledge of cheese manufacturing, their knowledge of hygienic practices may be limited. This mini-review provides an overview of the microbial quality of artisanal cheeses made by small family cheesemakers in Mexico and their manufacturing practices as factors affecting cheese microbial contamination.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"7 1","pages":"Pages 1-5"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ligia Cavani, Faith S. Reyes , Jennifer M.C. Van Os, Kent A. Weigel, Heather M. White, Francisco Peñagaricano
Social dominance is present in dairy production systems and affects performance, but it is difficult to measure. Latency to first meal after feed delivery may serve as a quantifiable phenotype for social dominance, given that dominant cows typically eat first. The goal of this study was to estimate the genetic variability of latency to first meal and evaluate its association with feed efficiency and feeding behavior in dairy cows. Data consisted of 6 million bunk visits from 1,770 mid-lactation Holstein cows collected from 2009 to 2024 at the University of Wisconsin–Madison using a roughage intake control system. Latency to first meal was calculated as the time it takes for a cow to access the feed following the feed delivery. The statistical model consisted of a repeatability animal model, with lactation and DIM as fixed effects, and cohort, animal, and permanent environment as random effects. Genetic parameters for latency to first meal were estimated using daily records and weekly averages. Heritability and repeatability of latency to first meal using daily records were 0.08 ± 0.01 and 0.22 ± 0.01, respectively. Heritability and repeatability of latency to first meal using weekly averages were 0.17 ± 0.03 and 0.43 ± 0.01, respectively. Genetic correlations between weekly averages of latency to first meal and DMI, milk energy, metabolic BW, and residual feed intake were −0.03 ± 0.08, −0.12 ± 0.08, 0.10 ± 0.06, and −0.08 ± 0.10, respectively. Latency to first meal was negatively correlated with number of visits at the feed bunk per day (−0.65 ± 0.06) and total duration of visits (−0.58 ± 0.05). Latency to first meal was positively correlated with duration of each visit (0.39 ± 0.07), intake per visit (0.65 ± 0.06), and feeding rate (0.51 ± 0.07). Overall, cows with longer latencies to eat had fewer but longer bunk visits, greater intake per visit, and ate at a faster rate. Latency to first meal may be a quantifiable phenotype for social dominance; it is both heritable and repeatable and is not correlated with feed efficiency.
{"title":"Social dominance and feed efficiency: Genetic analysis of latency to first meal after fresh feed delivery and residual feed intake in dairy cows","authors":"Ligia Cavani, Faith S. Reyes , Jennifer M.C. Van Os, Kent A. Weigel, Heather M. White, Francisco Peñagaricano","doi":"10.3168/jdsc.2025-0874","DOIUrl":"10.3168/jdsc.2025-0874","url":null,"abstract":"<div><div>Social dominance is present in dairy production systems and affects performance, but it is difficult to measure. Latency to first meal after feed delivery may serve as a quantifiable phenotype for social dominance, given that dominant cows typically eat first. The goal of this study was to estimate the genetic variability of latency to first meal and evaluate its association with feed efficiency and feeding behavior in dairy cows. Data consisted of 6 million bunk visits from 1,770 mid-lactation Holstein cows collected from 2009 to 2024 at the University of Wisconsin–Madison using a roughage intake control system. Latency to first meal was calculated as the time it takes for a cow to access the feed following the feed delivery. The statistical model consisted of a repeatability animal model, with lactation and DIM as fixed effects, and cohort, animal, and permanent environment as random effects. Genetic parameters for latency to first meal were estimated using daily records and weekly averages. Heritability and repeatability of latency to first meal using daily records were 0.08 ± 0.01 and 0.22 ± 0.01, respectively. Heritability and repeatability of latency to first meal using weekly averages were 0.17 ± 0.03 and 0.43 ± 0.01, respectively. Genetic correlations between weekly averages of latency to first meal and DMI, milk energy, metabolic BW, and residual feed intake were −0.03 ± 0.08, −0.12 ± 0.08, 0.10 ± 0.06, and −0.08 ± 0.10, respectively. Latency to first meal was negatively correlated with number of visits at the feed bunk per day (−0.65 ± 0.06) and total duration of visits (−0.58 ± 0.05). Latency to first meal was positively correlated with duration of each visit (0.39 ± 0.07), intake per visit (0.65 ± 0.06), and feeding rate (0.51 ± 0.07). Overall, cows with longer latencies to eat had fewer but longer bunk visits, greater intake per visit, and ate at a faster rate. Latency to first meal may be a quantifiable phenotype for social dominance; it is both heritable and repeatable and is not correlated with feed efficiency.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"7 1","pages":"Pages 56-60"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The morphology of the dairy cow mammary gland can indicate risk of disease and can change in response to various conditions. Collecting traditional measurements with a tape measure is time-consuming and can be subject to observer error. The objective of this cross-sectional study was to assess the agreement and reliability between traditionally collected measurements of the hind udder with measurements collected using a 3-dimensional (3D) scanner. We hypothesized there would be good reliability and agreement between methods. Adult cows in tiestalls at the Michigan State University dairy farm were used (n = 40). On 3 consecutive days, trained observers (n = 3) used a soft measuring tape to perform 3 measurements of the udder: a single vertical measurement from the rear udder attachment to the base of the quarter, and separate horizontal measurements of each quarter (left and right) from the medial cleft to the hind leg juncture. Marks were placed on the udders to guide traditionally collected measurements. A separate observer collected 3D scans (Structure Sensor, Occipital) and measured the same areas using 3-matic software (n = 120; Materialise, Belgium). Cows with mastitis (n = 3) and one incomplete scan were removed from the data, resulting in 37 cows with 999 and 333 traditional and 3D measurements, respectively. Intraclass correlation coefficients (ICC) among observers and between traditionally determined measurements and 3D measured were analyzed. Bland–Altman analysis was used to assess bias between traditional and 3D measurements. Linear regression was used to assess proportional bias between methods. The interobserver reliability was good to excellent for traditional measurements (ICC ≥0.88). Reliability between traditional and 3D measurements was good to excellent for all observers (ICC ≥0.87). Bland–Altman assessment found minimal bias between traditional and 3D measurements, except for 1 observer measurement of the right quarter. As compared with measurements from the 3D scanner, observers A and C consistently underestimated vertical measurements and overestimated the quarter measurements. Of results, 93% to 96% were within the upper and lower bounds of agreement. Observer C had positive proportional bias for vertical and right quarter measurements, indicating that as udder size increased, traditional measurements were overestimated as compared with 3D. These results indicate that the 3D scanner has a good to excellent reliability and adequate agreement with minimal bias in relation with the traditional measurements and may be used to collect hind udder measurements in healthy cows. These methods could be used to improve detection and assessment of conditions such as mastitis, though more research and validation studies are needed.
{"title":"Agreement and reliability of dairy cow udder morphometrics between traditional measurements and measurements from a 3-dimensional scanner","authors":"J.M. Strickland , C.I. Robison , P.H.E. Trindade , P.L. Ruegg","doi":"10.3168/jdsc.2025-0822","DOIUrl":"10.3168/jdsc.2025-0822","url":null,"abstract":"<div><div>The morphology of the dairy cow mammary gland can indicate risk of disease and can change in response to various conditions. Collecting traditional measurements with a tape measure is time-consuming and can be subject to observer error. The objective of this cross-sectional study was to assess the agreement and reliability between traditionally collected measurements of the hind udder with measurements collected using a 3-dimensional (3D) scanner. We hypothesized there would be good reliability and agreement between methods. Adult cows in tiestalls at the Michigan State University dairy farm were used (n = 40). On 3 consecutive days, trained observers (n = 3) used a soft measuring tape to perform 3 measurements of the udder: a single vertical measurement from the rear udder attachment to the base of the quarter, and separate horizontal measurements of each quarter (left and right) from the medial cleft to the hind leg juncture. Marks were placed on the udders to guide traditionally collected measurements. A separate observer collected 3D scans (Structure Sensor, Occipital) and measured the same areas using 3-matic software (n = 120; Materialise, Belgium). Cows with mastitis (n = 3) and one incomplete scan were removed from the data, resulting in 37 cows with 999 and 333 traditional and 3D measurements, respectively. Intraclass correlation coefficients (ICC) among observers and between traditionally determined measurements and 3D measured were analyzed. Bland–Altman analysis was used to assess bias between traditional and 3D measurements. Linear regression was used to assess proportional bias between methods. The interobserver reliability was good to excellent for traditional measurements (ICC ≥0.88). Reliability between traditional and 3D measurements was good to excellent for all observers (ICC ≥0.87). Bland–Altman assessment found minimal bias between traditional and 3D measurements, except for 1 observer measurement of the right quarter. As compared with measurements from the 3D scanner, observers A and C consistently underestimated vertical measurements and overestimated the quarter measurements. Of results, 93% to 96% were within the upper and lower bounds of agreement. Observer C had positive proportional bias for vertical and right quarter measurements, indicating that as udder size increased, traditional measurements were overestimated as compared with 3D. These results indicate that the 3D scanner has a good to excellent reliability and adequate agreement with minimal bias in relation with the traditional measurements and may be used to collect hind udder measurements in healthy cows. These methods could be used to improve detection and assessment of conditions such as mastitis, though more research and validation studies are needed.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"7 1","pages":"Pages 77-82"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lactobionic acid (LBA) and its salt form (e.g., lactobionate [LBN]) have emerged as high-value-added functional ingredients in food and pharmaceutical applications, such as acidulant, antioxidant, metal chelator, and carrier in drug delivery systems. Enzymatic oxidation has been employed as a nontoxic, cost-effective, and environmentally friendly approach for the synthesis of LBA/LBN. The current study investigated, first, the feasibility of producing calcium lactobionate (Ca-LBN) via enzymatic oxidation using cheese whey permeate as a substrate at high concentration, and second, the bioactivity of the resulting Ca-LBN. The production experiment was performed using reconstituted cheese whey permeate solution (300 g·L−1 lactose) as a substrate, Ca(OH)2 as a titrant base, oxidase (dosage: 400 U·kg−1 lactose), and catalase (dosage: 168,000 U·kg−1 lactose) in a laboratory bioreactor. Target critical control parameters, such as pH 6.40; dissolved oxygen: 44%; and temperature: 38°C, were defined and monitored using an industrial human-machine interface (HMI) to ensure operational stability. The consumption of Ca(OH)2 was used to calculate real-time molar conversion rate (MCRRT) and accumulative molar conversion yield (MCY) according to the pH-stat method. Enzymatic oxidation reaction continued for 7 h, and MCY was observed at nearly 99%. The MCRRT rapidly reached a plateau value of ∼470 mmol·h−1 within 20 min of the process. The critical operational parameters remained controlled by the HMI cascade, suggesting that the process is scalable. The DPPH-radical scavenging and ferrous ion chelating activity of the obtained LBN could not be confirmed based on the colorimetric assays used in the present work; however, characterization processes need to be further optimized. The obtained knowledge may be applied to the scalable production of LBA/LBN, enabling higher yields and an efficient manufacturing process.
{"title":"Enzymatic synthesis of calcium lactobionate from cheese whey permeate as a value-added ingredient","authors":"Usman Amin , Chi Kong Yeung , Haotian Zheng","doi":"10.3168/jdsc.2025-0834","DOIUrl":"10.3168/jdsc.2025-0834","url":null,"abstract":"<div><div>Lactobionic acid (LBA) and its salt form (e.g., lactobionate [LBN]) have emerged as high-value-added functional ingredients in food and pharmaceutical applications, such as acidulant, antioxidant, metal chelator, and carrier in drug delivery systems. Enzymatic oxidation has been employed as a nontoxic, cost-effective, and environmentally friendly approach for the synthesis of LBA/LBN. The current study investigated, first, the feasibility of producing calcium lactobionate (Ca-LBN) via enzymatic oxidation using cheese whey permeate as a substrate at high concentration, and second, the bioactivity of the resulting Ca-LBN. The production experiment was performed using reconstituted cheese whey permeate solution (300 g·L<sup>−1</sup> lactose) as a substrate, Ca(OH)<sub>2</sub> as a titrant base, oxidase (dosage: 400 U·kg<sup>−1</sup> lactose), and catalase (dosage: 168,000 U·kg<sup>−1</sup> lactose) in a laboratory bioreactor. Target critical control parameters, such as pH 6.40; dissolved oxygen: 44%; and temperature: 38°C, were defined and monitored using an industrial human-machine interface (HMI) to ensure operational stability. The consumption of Ca(OH)<sub>2</sub> was used to calculate real-time molar conversion rate (MCR<sub>RT</sub>) and accumulative molar conversion yield (MCY) according to the pH-stat method. Enzymatic oxidation reaction continued for 7 h, and MCY was observed at nearly 99%. The MCR<sub>RT</sub> rapidly reached a plateau value of ∼470 mmol·h<sup>−1</sup> within 20 min of the process. The critical operational parameters remained controlled by the HMI cascade, suggesting that the process is scalable. The DPPH-radical scavenging and ferrous ion chelating activity of the obtained LBN could not be confirmed based on the colorimetric assays used in the present work; however, characterization processes need to be further optimized. The obtained knowledge may be applied to the scalable production of LBA/LBN, enabling higher yields and an efficient manufacturing process.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"7 1","pages":"Pages 6-11"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
γδ T cells may regulate immune responses through interleukin-10 secretion and reduce cytotoxic and helper T cell proliferation, in vitro. γδ T cells are prominent in ruminant peripheral blood, but their presence in a recently defined ruminal immune cell population remains unclear. Our study aimed to determine the relative proportions of T cell types within rumen tissue (heterogeneous tissue consisting of lamina propria, stratified epithelium, and vasculature) of healthy dairy cows through spectral flow cytometry, and we hypothesized that the largest proportion of ruminal T cells would be γδ T cells. We used spectral flow cytometry to assess ruminal and peripheral blood T cell proportions. The panel included CD45 (leukocytes), CD3 (T lymphocytes), CD4 (helper T cells), and TCRN-24 (γδ T cells). Results were analyzed with a mixed linear model that included the effect of blood versus rumen tissue and the random effect of cow. Cows were clinically healthy throughout the experiment, as indicated by their DMI (26.0 ± 3.44 kg/d), milk yield (50.6 ± 12.99 kg/d; mean ± SD), and ruminal pH (6.06 ± 0.55). CD3+ cells constituted 83.9% ± 2.85% (mean ± SEM) of ruminal CD45+ cells compared with 3.3% ± 2.85% of CD45+ cells in blood. On a CD3+ basis, TCRN24+ were the most prominent subset of T lymphocytes in rumen tissue samples and were enriched compared with blood (78.7% ± 6.92% of CD3+ vs. 38.1 ± 6.92% of CD3+). The CD4+ were reduced as a proportion of T cells in the rumen compared with blood (1.4% ± 1.95% of CD3+ vs. 21.4 ± 1.95% of CD3+). We observed a TCRN24+CD4+ population isolated from the rumen which was lesser in blood (9.0% ± 2.72% of CD3+ vs. 1.5 ± 2.72% of CD3+). We confirmed our hypothesis that γδ T cells are the most prominent proportion of T cells within the rumen tissue in healthy lactating dairy cows. Furthermore, we observed a unique population that was both TCRN24+ and CD4+; investigations of this potential T cell subtype are needed to confirm their presence and determine their function. Understanding the role of T lymphocytes in rumen immunity may guide strategies that strengthen rumen health and digestion while reducing gut-derived inflammation.
{"title":"Initial characterization of ruminal T lymphocytes in lactating dairy cows","authors":"Lolita Vandevoorde, Kirby Krogstad","doi":"10.3168/jdsc.2025-0838","DOIUrl":"10.3168/jdsc.2025-0838","url":null,"abstract":"<div><div>γδ T cells may regulate immune responses through interleukin-10 secretion and reduce cytotoxic and helper T cell proliferation, in vitro. γδ T cells are prominent in ruminant peripheral blood, but their presence in a recently defined ruminal immune cell population remains unclear. Our study aimed to determine the relative proportions of T cell types within rumen tissue (heterogeneous tissue consisting of lamina propria, stratified epithelium, and vasculature) of healthy dairy cows through spectral flow cytometry, and we hypothesized that the largest proportion of ruminal T cells would be γδ T cells. We used spectral flow cytometry to assess ruminal and peripheral blood T cell proportions. The panel included CD45 (leukocytes), CD3 (T lymphocytes), CD4 (helper T cells), and TCRN-24 (γδ T cells). Results were analyzed with a mixed linear model that included the effect of blood versus rumen tissue and the random effect of cow. Cows were clinically healthy throughout the experiment, as indicated by their DMI (26.0 ± 3.44 kg/d), milk yield (50.6 ± 12.99 kg/d; mean ± SD), and ruminal pH (6.06 ± 0.55). CD3+ cells constituted 83.9% ± 2.85% (mean ± SEM) of ruminal CD45+ cells compared with 3.3% ± 2.85% of CD45+ cells in blood. On a CD3+ basis, TCRN24+ were the most prominent subset of T lymphocytes in rumen tissue samples and were enriched compared with blood (78.7% ± 6.92% of CD3+ vs. 38.1 ± 6.92% of CD3+). The CD4+ were reduced as a proportion of T cells in the rumen compared with blood (1.4% ± 1.95% of CD3+ vs. 21.4 ± 1.95% of CD3+). We observed a TCRN24+CD4+ population isolated from the rumen which was lesser in blood (9.0% ± 2.72% of CD3+ vs. 1.5 ± 2.72% of CD3+). We confirmed our hypothesis that γδ T cells are the most prominent proportion of T cells within the rumen tissue in healthy lactating dairy cows. Furthermore, we observed a unique population that was both TCRN24+ and CD4+; investigations of this potential T cell subtype are needed to confirm their presence and determine their function. Understanding the role of T lymphocytes in rumen immunity may guide strategies that strengthen rumen health and digestion while reducing gut-derived inflammation.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"7 1","pages":"Pages 107-112"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Visentin , I. Sousa , S. Magro, S. Sabbadin, G. Niero, M. De Marchi
The possibility of monitoring allantoin, creatinine, and uric acid in individual cow urine can provide insights into the physiological responses of dairy cows under heat stress conditions and offer information on nitrogen metabolism. The aim of this study was to validate a reversed-phase HPLC method for the simultaneous quantification of allantoin, creatinine, and uric acid in dairy cow urine. Urine samples were collected from 10 lactating Holstein cows and were analyzed in triplicate for 5 consecutive days, for an overall total of 150 analyses. The method demonstrated good repeatability and reproducibility performances. In particular, repeatability coefficients exceeded 99% for allantoin and creatinine, and surpassed 95% for uric acid. Among the compounds analyzed in the present study, creatinine and uric acid exhibited the highest and the lowest coefficient of reproducibility (99.39% and 78.03%, respectively). The method exhibited optimal linearity for dilutions between 1:20 (i.e., 1 part of urine and 20 parts of water) and 1:8 (i.e., 1 part of urine and 8 parts of water), with R2 ranging from 0.98 to 0.99 for uric acid and allantoin, respectively. The best recovery rates were obtained at the highest spike level for allantoin (102.97%), at the medium spike level for creatinine (98.70%), and at the lowest spike level for uric acid (95.61%). This study may lay the groundwork for future research on the association between novel urine biomarkers and temperature and humidity indexes.
{"title":"Validation of a reversed-phase high-performance liquid chromatography method for quantification of allantoin, creatinine, and uric acid in individual spot cow urine samples","authors":"E. Visentin , I. Sousa , S. Magro, S. Sabbadin, G. Niero, M. De Marchi","doi":"10.3168/jdsc.2025-0855","DOIUrl":"10.3168/jdsc.2025-0855","url":null,"abstract":"<div><div>The possibility of monitoring allantoin, creatinine, and uric acid in individual cow urine can provide insights into the physiological responses of dairy cows under heat stress conditions and offer information on nitrogen metabolism. The aim of this study was to validate a reversed-phase HPLC method for the simultaneous quantification of allantoin, creatinine, and uric acid in dairy cow urine. Urine samples were collected from 10 lactating Holstein cows and were analyzed in triplicate for 5 consecutive days, for an overall total of 150 analyses. The method demonstrated good repeatability and reproducibility performances. In particular, repeatability coefficients exceeded 99% for allantoin and creatinine, and surpassed 95% for uric acid. Among the compounds analyzed in the present study, creatinine and uric acid exhibited the highest and the lowest coefficient of reproducibility (99.39% and 78.03%, respectively). The method exhibited optimal linearity for dilutions between 1:20 (i.e., 1 part of urine and 20 parts of water) and 1:8 (i.e., 1 part of urine and 8 parts of water), with R<sup>2</sup> ranging from 0.98 to 0.99 for uric acid and allantoin, respectively. The best recovery rates were obtained at the highest spike level for allantoin (102.97%), at the medium spike level for creatinine (98.70%), and at the lowest spike level for uric acid (95.61%). This study may lay the groundwork for future research on the association between novel urine biomarkers and temperature and humidity indexes.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"7 1","pages":"Pages 113-118"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Rinn , A.K. Neff , G. Fincham , P.J. Kononoff , A.L. Carroll
Some feed additives that mitigate enteric methane (CH4) production can result in an increase in hydrogen (H2) production. When expelled to the environment, H2 may intensify competition for hydroxyl radicals, prolonging CH4 persistence in the atmosphere. Therefore, the objective of the experiment was to determine the effects of adding 2-bromoethanesulfonate (BE) alone and in combination with monensin or calcium propionate on in vitro ruminal CH4 and H2 production. Using 3 separate runs, 1 g of 50% corn silage and 50% alfalfa (DM basis) was fermented (1) alone (control; CON); (2) CON with 100 μM BE (BES); (3) BES + 2.5 μM monensin (BM); and (4) BES + 2.5% DM calcium propionate (BC). Inoculum was obtained by collecting a mixture of rumen fluid from 2 steers (BW = 657 ± 12.5 kg) consuming a diet of 30% concentrate and 70% roughage. For each treatment within run, gas production was measured over a 48-h period using 2 randomly assigned paired and separate modules. Total CH4 and H2 production were calculated by multiplying the total volume of gas produced by the concentration of CH4 and H2 determined by gas chromatography at 0, 4, 8, 18, 24, and 48 h. Data were blocked by run and analyzed as a repeated measures randomized complete block design using the GLIMMIX procedure of SAS (v. 9.4) where treatment, time and the interaction between these 2 factors were considered as fixed effects and module, run and the interaction were included as random effects. Significance was declared at P ≤ 0.05. The BES, BM, and BC treatments did not differ in CH4 production (g/h) at 4 and 8 h of incubation, averaging 0.005 and 0.013 ± 0.0020 g/h, respectively, but CH4 production was reduced compared with the CON (0.017 and 0.047 ± 0.0018 g/h CH4, respectively). At 8 h, BES increased H2 production relative to BM and BC (0.002 and 0.0014 ± 0.0002 g/h H2, respectively), but all treatments containing BES were significantly greater than CON (0 vs. 0.002 ± 0.0002 H2 g/h). In conclusion, treatments containing BES reduced CH4, and the addition of calcium propionate or monensin may serve as a short-term strategy for the reduction of H2 resulting from mitigation of enteric CH4 production.
{"title":"Effects of 2-bromoethanesulfonate alone or in combination with calcium propionate or monensin on methane and gaseous hydrogen production during in vitro rumen fermentation","authors":"B. Rinn , A.K. Neff , G. Fincham , P.J. Kononoff , A.L. Carroll","doi":"10.3168/jdsc.2025-0795","DOIUrl":"10.3168/jdsc.2025-0795","url":null,"abstract":"<div><div>Some feed additives that mitigate enteric methane (CH<sub>4</sub>) production can result in an increase in hydrogen (H<sub>2</sub>) production. When expelled to the environment, H<sub>2</sub> may intensify competition for hydroxyl radicals, prolonging CH<sub>4</sub> persistence in the atmosphere. Therefore, the objective of the experiment was to determine the effects of adding 2-bromoethanesulfonate (BE) alone and in combination with monensin or calcium propionate on in vitro ruminal CH<sub>4</sub> and H<sub>2</sub> production. Using 3 separate runs, 1 g of 50% corn silage and 50% alfalfa (DM basis) was fermented (1) alone (control; CON); (2) CON with 100 μ<em>M</em> BE (BES); (3) BES + 2.5 μ<em>M</em> monensin (BM); and (4) BES + 2.5% DM calcium propionate (BC). Inoculum was obtained by collecting a mixture of rumen fluid from 2 steers (BW = 657 ± 12.5 kg) consuming a diet of 30% concentrate and 70% roughage. For each treatment within run, gas production was measured over a 48-h period using 2 randomly assigned paired and separate modules. Total CH<sub>4</sub> and H<sub>2</sub> production were calculated by multiplying the total volume of gas produced by the concentration of CH<sub>4</sub> and H<sub>2</sub> determined by gas chromatography at 0, 4, 8, 18, 24, and 48 h. Data were blocked by run and analyzed as a repeated measures randomized complete block design using the GLIMMIX procedure of SAS (v. 9.4) where treatment, time and the interaction between these 2 factors were considered as fixed effects and module, run and the interaction were included as random effects. Significance was declared at <em>P</em> ≤ 0.05. The BES, BM, and BC treatments did not differ in CH<sub>4</sub> production (g/h) at 4 and 8 h of incubation, averaging 0.005 and 0.013 ± 0.0020 g/h, respectively, but CH<sub>4</sub> production was reduced compared with the CON (0.017 and 0.047 ± 0.0018 g/h CH<sub>4</sub>, respectively). At 8 h, BES increased H<sub>2</sub> production relative to BM and BC (0.002 and 0.0014 ± 0.0002 g/h H<sub>2</sub>, respectively), but all treatments containing BES were significantly greater than CON (0 vs. 0.002 ± 0.0002 H<sub>2</sub> g/h). In conclusion, treatments containing BES reduced CH<sub>4</sub>, and the addition of calcium propionate or monensin may serve as a short-term strategy for the reduction of H<sub>2</sub> resulting from mitigation of enteric CH<sub>4</sub> production.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"7 1","pages":"Pages 18-22"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shannon C. Beard , Mark E. Carson , Bonnie Mallard , Michael Lohuis , Francesca Malchiodi
The spillover of highly pathogenic avian influenza (HPAI) hemagglutinin type 5 and neuraminidase type 1 (H5N1) into dairy cattle marks the emergence of a new threat to herd health and production efficiency for North American dairy cattle. To address this challenge, this study evaluated whether genetic selection for improved immune response, using Immunity+ GEBVs, can increase resilience to HPAI H5N1 in commercial dairy herds. Treatment records (n = 15,386) and daily milk yield data (n = 650) were obtained from herd management software from 6 large commercial dairy herds in the United States with confirmed HPAI H5N1 outbreaks. The association between Immunity+ GEBV classes and the likelihood of requiring supportive treatment was assessed using binomial logistic regression, while linear models were used to assess the effects of Immunity+ GEBV class on the length of the milk fluctuation period following treatment and total milk loss during this period. Cows with high Immunity+ GEBVs were 24% less likely to require supportive treatment compared with those with low Immunity+ GEBVs (odds ratio = 0.76; 95% CI: 0.64 to 0.9). High immunity cows also experienced significantly lower milk loss (484.46 kg; 95% CI: 440.61 to 528.30 kg) during the post-treatment fluctuation period compared with low immunity cows (618.10 kg; 95% CI: 561.08 to 675.12 kg). Overall, these findings support the value of selecting for enhanced immune response to improve animal health, reduce production losses, and strengthen economic resilience during disease challenges.
{"title":"High immune responder cows have lower treatment risk and reduced milk loss during highly pathogenic avian influenza H5N1 outbreaks","authors":"Shannon C. Beard , Mark E. Carson , Bonnie Mallard , Michael Lohuis , Francesca Malchiodi","doi":"10.3168/jdsc.2025-0869","DOIUrl":"10.3168/jdsc.2025-0869","url":null,"abstract":"<div><div>The spillover of highly pathogenic avian influenza (HPAI) hemagglutinin type 5 and neuraminidase type 1 (H5N1) into dairy cattle marks the emergence of a new threat to herd health and production efficiency for North American dairy cattle. To address this challenge, this study evaluated whether genetic selection for improved immune response, using Immunity+ GEBVs, can increase resilience to HPAI H5N1 in commercial dairy herds. Treatment records (n = 15,386) and daily milk yield data (n = 650) were obtained from herd management software from 6 large commercial dairy herds in the United States with confirmed HPAI H5N1 outbreaks. The association between Immunity+ GEBV classes and the likelihood of requiring supportive treatment was assessed using binomial logistic regression, while linear models were used to assess the effects of Immunity+ GEBV class on the length of the milk fluctuation period following treatment and total milk loss during this period. Cows with high Immunity+ GEBVs were 24% less likely to require supportive treatment compared with those with low Immunity+ GEBVs (odds ratio = 0.76; 95% CI: 0.64 to 0.9). High immunity cows also experienced significantly lower milk loss (484.46 kg; 95% CI: 440.61 to 528.30 kg) during the post-treatment fluctuation period compared with low immunity cows (618.10 kg; 95% CI: 561.08 to 675.12 kg). Overall, these findings support the value of selecting for enhanced immune response to improve animal health, reduce production losses, and strengthen economic resilience during disease challenges.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"7 1","pages":"Pages 72-76"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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