Journal of Dairy Science最新文献

{"title":"Usefulness of differential somatic cell count for udder health monitoring: Identifying referential values for differential somatic cell count in healthy quarters and quarters with subclinical mastitis","authors":"Mariana Fonseca ,&nbsp;Daryna Kurban ,&nbsp;Jean-Philippe Roy ,&nbsp;Débora E. Santschi ,&nbsp;Elouise Molgat ,&nbsp;Danchen Aaron Yang ,&nbsp;Simon Dufour","doi":"10.3168/jds.2024-25403","DOIUrl":"10.3168/jds.2024-25403","url":null,"abstract":"<div><div>Mastitis, an inflammation of the udder primarily caused by an IMI, is one of the most common diseases in dairy cattle. Somatic cell count has been widely used as an indicator of udder inflammation, assisting in the detection of subclinical mastitis. More recently, differential SCC (DSCC), which represents the combined proportion of lymphocytes and polymorphonuclear leukocytes, has become available for routine dairy milk screening, although it was not yet widely studied. Therefore, the objective of this study was to assess and compare the usefulness of quarter-level SCS or DSCC to predict the probability of subclinical mastitis. Additionally, our goals included estimating the sensitivity (Se) and specificity (Sp) of SCS and DSCC across all potential cut-off values. The current study was an observational study conducted on commercial dairy farms. Five dairy herds were selected using a convenience sampling. A Gaussian finite mixture model (GFMM) was applied to investigate the latent quarter subclinical mastitis status with either measurement, SCS or DSCC. Posterior values for SCS and DSCC obtained from the GFMM were used for predictive estimation of the parameters. The estimated SCS distribution for healthy quarters had a mean (SD) of 1.4 (1.3), and, for quarters with subclinical mastitis, it was 4.5 (2.4). For DSCC, the estimated mean was 55.6% (15.2) for healthy quarters, whereas it was 80.4% (6.4) for quarters with subclinical mastitis. The most discriminant cut-off for SCS, as indicated by the Youden index, was 3.0, corresponding to exactly 100,000 cells/mL. At this threshold, the Se and Sp of SCS were 0.73 (95% Bayesian credible interval [BCI]: 0.70–0.77) and 0.90 (95% BCI: 0.89–0.91), respectively. The most discriminant cut-off point for DSCC was 70.0%, with corresponding Se and Sp values of 0.95 (0.93, 0.96) and 0.83 (0.81, 0.85), respectively. For the SCS analysis, we obtained predictive probabilities of subclinical mastitis approaching 0 and 100%, with only a narrow range of SCS results yielding intermediate probabilities. On the other hand, predictive probabilities ranging from 0 to 90% were obtained for DSCC analysis, with a large range of DSCC results presenting intermediate probabilities. Thus, SCS seemed to surpass DSCC for predicting subclinical mastitis. These findings provided a foundation for future studies to further explore and validate the efficacy of GFMM for diagnostic tests yielding quantitative results.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 3917-3928"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142851916","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":"Prepartum supplementation of Ascophyllum nodosum meal or ethylenediamine dihydroiodide: Effects on colostrum yield and growth and health of dairy calves","authors":"K.R. Johnston ,&nbsp;D.C. Reyes ,&nbsp;K.N. Klobucher ,&nbsp;T.C. Stahl ,&nbsp;N.N. Price ,&nbsp;P.S. Erickson ,&nbsp;A.F. Brito","doi":"10.3168/jds.2024-25559","DOIUrl":"10.3168/jds.2024-25559","url":null,"abstract":"<div><div>We aimed to evaluate the effects of prepartum supplementation of different I sources (<em>Ascophyllum nodosum</em> [ASCO] meal and ethylenediamine dihydroiodide [EDDI]) on colostrum yield, blood concentrations of glucose, BHB, and thyroid hormones, and growth of dairy calves. Forty multiparous Holstein cows were blocked by lactation number and expected calving date and assigned to 1 of 4 treatments 28 d before parturition: (1) EDDI supplemented (11 mg/d) to a basal diet to meet the <span><span>NRC (2001)</span></span> I concentration of 0.5 mg of I/kg of DMI (control = CON [0 g/d of ASCO meal]; actual I concentration = 0.68 mg/kg of DMI); (2) CON plus 57 g/d of ASCO meal (low seaweed supplementation = LSW); (3) CON plus 113 g/d of ASCO meal (high seaweed supplementation = HSW); or (4) CON plus 151.3 mg/d of EDDI formulated to match the amount of I provided by HSW (high EDDI = HEDDI). Forty-one calves were blocked based on their dams' treatments and received 300 g of IgG via colostrum replacer immediately after birth. At 24 h after calving, calves were offered (DM basis) 676 g of milk replacer (25.3% CP, 16.5% fat) until d 49 and 338 g until weaning. Free-choice texturized starter (28.2% CP) and water were offered ad libitum from 24 h to 8 wk of life. Blood samples were collected for analyses of IgG (0 h and 24 h of age), thyroid hormones (d 14, 28, and 56 of age), and BHB (weekly). On d 5 of life, a xylose challenge was conducted by supplementing 0.5 g of <span>d</span>-xylose/kg of BW, with blood samples taken over a 12-h period. Weekly skeletal and BW measurements were also recorded. The concentration of colostral fat was greater in HSW than HEDDI cows, and it tended to increase linearly with ASCO meal supplementation. Although I intake increased linearly with feeding incremental amounts of ASCO meal to close-up cows, the transfer of I from feed to colostrum decreased quadratically. Neither I intake nor colostral I transfer efficiency changed when feeding HSW versus HEDDI. Calves born to HSW dams had a greater initial BW and final hip height, as well as tendencies for greater weekly hip height and final withers height compared with HEDDI calves. Calf BW gain tended to decrease linearly with ASCO meal supplementation. The 24-h apparent efficiency of absorption of IgG tended to increase in HSW versus HEDDI calves. Plasma glucose concentration on d 5 of life decreased linearly in response to incremental levels of ASCO meal. Furthermore, the plasma concentration of biweekly total thyroxin and whole-blood concentrations of weekly BHB and final BHB responded quadratically to ASCO meal, with the lowest values observed for LSW calves. In summary, prepartum supplementation with incremental amounts of ASCO meal to close-up cows did not change colostrum composition. However, feeding HSW versus HEDDI increased colostral fat concentration and initial BW in calves.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 3586-3601"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142997748","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":"An investigation into the factors associated with pregnancy-associated glycoproteins in milk in seasonal-calving, pasture-based dairy cows","authors":"R.C. Doyle ,&nbsp;M.M. Herlihy ,&nbsp;J. Kenneally ,&nbsp;M.C. Lucy ,&nbsp;S.T. Butler","doi":"10.3168/jds.2024-25774","DOIUrl":"10.3168/jds.2024-25774","url":null,"abstract":"<div><div>Pregnancy-associated glycoproteins (PAG) are secreted by trophoblast giant cells, and are detectable in blood and milk within the first month of gestation. The PAG concentration in blood and milk is believed to be 1 indicator of placental function and predictive of pregnancy maintenance. The objective of this retrospective study was to investigate factors associated with milk PAG sample minus the negative control mean optical density (S-N) profiles in cows managed under a seasonal-calving, pasture-based production system. Spring-calving dairy cows (n = 496) located in 3 Teagasc Research Farms in Ireland were enrolled in the study. Milk samples were collected weekly from each cow from wk 5 to 21 after artificial insemination (AI) to determine milk PAG S-N values. Body condition score was measured every 2 wk on a scale of 1 to 5 with 0.25 increments. Only cows that conceived to first AI and maintained pregnancy were retained for the final analysis (n = 247). Mixed models were used to evaluate the fixed effects of week after AI, BCS, dam fertility index (FI) and milk index, milk yield category, sire, parity, calf gender and calf birthweight on weekly milk PAG S-N profile, initial peak PAG, nadir PAG, and postnadir recovery peak PAG. Week after AI was associated with milk PAG S-N values, with mean week (and 95% CI) of initial peak values observed on week 6.4 (6.2, 6.5) after AI, nadir values on week 8.6 (8.55, 8.90) after AI, followed by recovery thereafter. We observed associations between parity, dam FI, milk yield, sire of the gestating embryo/fetus, fetal gender, and full-term calf birthweight with different aspects of the PAG S-N profile. Cows with the greatest FI had greater milk PAG S-N values at wk 5 and 6 after AI compared with cows with intermediate FI and least FI. There was also an association with parity because parity 1 cows had greater milk PAG S-N values than parity 2 and parity 3 cows during the initial peak and nadir stages of the PAG profile. An effect of sire on nadir milk PAG S-N values was observed, with PAG S-N values ranging from 0.5 to 1.2 between sires. In summary, milk PAG concentrations were associated with dam genetic merit, phenotypic milk production, and fetal characteristics. Assuming a correlation between milk PAG S-N values and placental function, these data provide evidence for an effect of genetic selection for fertility traits on placental development or function, or both.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 4332-4348"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073053","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":"Liquid chromatography-mass spectrometry-based identification of casein variants in Dutch goat milk and their effect on casein composition, protein content, and micelle size","authors":"Swantje Breunig ,&nbsp;Rayner Gonzalez-Prendes ,&nbsp;Richard P.M.A. Crooijmans ,&nbsp;Kasper Hettinga ,&nbsp;Henk Bovenhuis ,&nbsp;Etske Bijl","doi":"10.3168/jds.2024-25823","DOIUrl":"10.3168/jds.2024-25823","url":null,"abstract":"<div><div>Casein polymorphism can be related to compositional differences in milk. The objective of this study was to identify CN variants in the Dutch goat population and to investigate their relation to CN composition, protein content, and CN micelle size. In this study, the CN variants were identified for 234 goats based on the intact protein mass determined by liquid chromatography (LC)-MS. The highest number of protein variants was detected for κ-CN and α_S1-CN. The effect of CN variants was studied using a mixed linear model accounting for family relations among goats. The results indicate that CN composition, protein content, and micelle size are heritable traits. External goat-related factors (e.g., parity, lactation stage) were less relevant for the studied traits. The results show that variants of α_S1-CN affect protein content in goat milk. The relative CN composition and CN micelle size were mainly affected by variants of α_S1-CN and α_S2-CN. Variants affecting the CN composition also affected CN micelle size. This study highlights the importance of considering all CN fractions when determining the effects of CN variants on milk traits in goat milk. The Dutch goat population differed in certain aspects from other dairy goat breeds, mainly in variants of α_S1-CN and α_S2-CN, which may also explain differences in overall CN composition.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 3258-3272"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073296","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":"Mineral profile of cow milk and plant-based milk alternatives","authors":"Irene Cristina Antunes ,&nbsp;Ricardo Bexiga ,&nbsp;Carlos Pinto ,&nbsp;Luísa Louro Martins ,&nbsp;Miguel Mourato ,&nbsp;Gonçalo Pereira ,&nbsp;Elsa Vieira ,&nbsp;Cristina Delerue-Matos ,&nbsp;Mário Quaresma","doi":"10.3168/jds.2024-25752","DOIUrl":"10.3168/jds.2024-25752","url":null,"abstract":"<div><div>Some consumers are replacing cow milk by plant-based milk alternatives (PBMA); however, the current knowledge regarding the mineral profile of PBMA is limited. This study aimed to characterize the mineral profile of commercial milk (n = 80) and PBMA types (n = 60; soya, rice, oat, almond, coconut, and hazelnut) by inductively coupled plasma–optical emission spectroscopy, along with a modification of the Sandell-Kolthoff reaction (iodine determination). A single fixed-effect statistical model considering the type of beverage as an independent variable was applied. Soya PBMA presented higher contents of Ca, Mg, Cu, and Mg than commercial milk, and similar contents of K and P. In contrast, commercial milk had higher contents of S, Zn, and Se, with the latter being below the limit of quantification (10 µg/kg) in all PBMA types. Both almond and hazelnut PBMA displayed I contents similar to those of commercial milk. In terms of mineral ratios, PBMA types presented a higher Ca/P compared with commercial milk, being aligned with dietary guidelines, whereas commercial milk and soya PBMA showing lower Na/K values, which are beneficial for cardiovascular health. Due to their variability, it is difficult to say with certainty that PBMA can reliably substitute milk as a source of minerals.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 3324-3333"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073316","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":"The food fermentation fungus Aspergillus oryzae is a source of natural antimicrobials against Listeria monocytogenes","authors":"Zepeng Tu ,&nbsp;Dasol Choi ,&nbsp;Yuxing Chen ,&nbsp;Jae-Hyuk Yu ,&nbsp;TuAnh N. Huynh","doi":"10.3168/jds.2024-25719","DOIUrl":"10.3168/jds.2024-25719","url":null,"abstract":"<div><div><em>Listeria monocytogenes</em> is a highly adaptable foodborne pathogen that causes multiple foodborne illness outbreaks annually despite stringent food safety measures. The ubiquitous presence of <em>L. monocytogenes</em> in agricultural production environments provides easy routes of contamination to the human food production chain. The remarkable resilience of <em>L. monocytogenes</em> in harsh food processing and preservation conditions presents further challenges to controlling this pathogen in food and food processing plants. Furthermore, there is an increasing consumer demand for natural antimicrobials in food. <em>Aspergillus oryzae</em> is a food fermentation fungus with a generally recognized as safe status and is a workhorse in biotechnology applications. In this study, we examined the antimicrobial activity of <em>Aspergillus oryzae</em> fermentates and extracts toward <em>L. monocytogenes</em>, both in laboratory cultures and contaminated milk. <em>Aspergillus oryzae</em>-derived antimicrobials can be obtained in 2 culture conditions, which we term natural products 1 and 2 (NP1 and NP2). Laboratory cultures of <em>L. monocytogenes</em> were effectively and rapidly killed by both NP1 and NP2 extracts. In contaminated milk, the NP1 extract was bactericidal, whereas the NP2 extract was bacteriostatic. Nevertheless, the NP2 extract was heat stable, retaining antimicrobial activity even after boiling. Profiling <em>L. monocytogenes</em> transcriptional response to a subinhibitory level of NP2 fermentate, we observed significant shifts in amino acid metabolism and iron uptake, suggesting that these pathways can be tackled to increase the efficacy of NP2. Taken together, <em>A. oryzae</em> fermentates and extracts are promising candidates for natural antimicrobial treatments in food and food processing environments.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 3444-3454"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143412729","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":"Dairy product and dairy iodine intake among pregnant women in 2 provinces of China: A cross-sectional study","authors":"Ying Zhang,&nbsp;Wei Ma,&nbsp;Jianqiang Wang,&nbsp;Xiuwei Li,&nbsp;Haiyan Wang,&nbsp;Jinpeng Wang,&nbsp;Jing Xu","doi":"10.3168/jds.2024-25845","DOIUrl":"10.3168/jds.2024-25845","url":null,"abstract":"<div><div>Dairy products, a good source of iodine, have been shown to influence the iodine level of pregnant women. This study aimed to investigate the dairy iodine content, the dairy products, and dairy iodine intake of Chinese pregnant women, and related factors. A cross-sectional study included 1,013 pregnant women in Liaoning and Yunnan provinces, China. The eligible participants completed the intake records for 30 consecutive days to collect characteristics and dairy consumption. Dairy iodine intake was calculated, and the related factors were explored using the Mann-Whitney, Kruskal-Wallis H, and Jonckheere-Terpstra trend tests. An analysis compared dairy iodine intake in pregnant women to the dietary reference intakes of iodine. The iodine content of pasteurized milk (26.3 μg/100 g vs. 14.7 μg/100 g, Z = −2.335) and yogurt (21.5 μg/100 g vs. 12.6 μg/100 g, Z = −2.668) was significantly higher in Liaoning than in Yunnan province. The average dairy intake of pregnant women was 147.4 g/d, and dairy iodine intake was 31.9 μg/d. There were significant differences in dairy iodine intake by age group, province, urban or rural area, ethnicity, and education levels. The median dairy iodine intake in this study only met 12.9% to 23.4% of the estimated average requirement and 9.0% to 16.3% of the recommended nutrient intake (RNI) of local pregnant women in the 2 provinces, respectively. Consuming 500 g of dairy products provides ∼92.5 to 121.0 μg of iodine. Combined with typical iodine intake from iodized salt and other foods, this would help pregnant women meet 105% to 117% of the RNI for iodine. In conclusion, pregnant women with low levels of education, in rural areas, or from the Lahu ethnic group have a lower intake of dairy products and dairy iodine. Approximately 500 g of dairy products plus 5 g of iodized salt and other foods per day will ensure adequate iodine intake for pregnant women in areas with low water iodine.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 3162-3171"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143475966","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":"Metabolic and inflammatory response to an early lactation intravenous lipopolysaccharide challenge in Holstein cows fed differing levels of metabolizable protein during the transition period","authors":"Trent A. Westhoff ,&nbsp;Tawny L. Chandler ,&nbsp;Anja S. Sipka ,&nbsp;Thomas R. Overton ,&nbsp;Andres F. Ortega ,&nbsp;Mike E. Van Amburgh ,&nbsp;Sabine Mann","doi":"10.3168/jds.2024-25675","DOIUrl":"10.3168/jds.2024-25675","url":null,"abstract":"<div><div>The nadir in transition cow nutrient balance coincides with a period of heightened inflammation. Decreased circulating AA might contribute to an altered immune phenotype that favors a proinflammatory response. Objectives were to (1) investigate the effect of increasing MP supply in the prepartum, postpartum, or both diets on the response to an intravenous (IV) LPS challenge, (2) compare the response of IV LPS to fasted unstimulated control cows, and (3) determine the duration of the effect of IV LPS or fasting on milk production. Multiparous cows (n = 96) were assigned to 1 of 4 treatment groups at 28 d before expected calving following a randomized block design. Prepartum diets were formulated to contain either a control (85 g of MP/kg of DM) or high (113 g of MP/kg of DM) level of MP. Postpartum diets were formulated to contain either a control (104 g of MP/kg of DM) or high (131 g of MP/kg of DM) level of MP. To control the potential confounding effects of Met and Lys supply, diets were formulated to supply an equal amount at 1.24 and 3.84 g/Mcal of ME in both prepartum diets and 1.15 and 3.16 g/Mcal of ME in both postpartum diets, respectively. The combination of a pre- and postpartum diet resulted in 4 treatment groups: control-control, control-high, high-control, and high-high. Cows (n = 24; 23 ± 2 DIM) were selected to undergo an IV LPS challenge (0.0625 µg/kg of BW over 1 h; IVLPS) in 6 blocks. Each block included 1 cow from each treatment and 1 unchallenged control cow (n = 6; DIM = 22 ± 2; CON) alternating between treatments. All cows were allowed 1 h of ad libitum feed intake before IV LPS and fasted for 10 h following challenge. Separate repeated measure ANOVA models were used to compare the effects of dietary treatment and IV LPS. Dietary treatment did not affect the clinical, inflammatory, or hematologic response to IV LPS. Compared with baseline values, DMI and milk yield decreased on the day of challenge 14.0% and 17.7% in IVLPS and 13.8% and 4.0% in CON, respectively. Compared with CON, IVLPS decreased leukocyte counts at 1 and 4 h and increased tumor necrosis factor from 1 to 4 h, IL-10 from 1 to 6 h, and haptoglobin from 24 to 72 h. Intravenous LPS increased concentrations of glucose at 10 h and decreased those of BHB at 10 h, fatty acid at 6 and 10 h, and calcium from 3 to 10 h relative to challenge. Intravenous LPS decreased circulating EAA from 2 to 8 h and NEAA at 4 h relative to challenge. Fasting and IVLPS decreased milk yield on the day of challenge compared with cows from the source population but milk recovered by d 2 relative to challenge. In conclusion, MP supply did not modify the inflammatory response to IV LPS, but IV LPS altered the metabolic response compared with CON. Furthermore, fasted and IV LPS-challenged animals recovered milk production within 2 d postchallenge.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 4263-4282"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143833809","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":"Temperature preferences of dairy calves for heated calf hutches during winter in a temperate climate","authors":"N. Sonntag ,&nbsp;F. Sutter ,&nbsp;S. Borchardt ,&nbsp;J.L. Plenio ,&nbsp;W. Heuwieser","doi":"10.3168/jds.2024-25271","DOIUrl":"10.3168/jds.2024-25271","url":null,"abstract":"<div><div>Newborn calves face challenges adapting from the warm uterine environment to cold ambient temperatures, and often experience cold stress. The objective of this study was to assess the preferred inside hutch temperature of dairy calves in their first week after birth during Central European winter and to compare lying behavior in heated and nonheated hutches. Sixteen matched pairs of dairy calves (2.6 ± 1.3 d old) were enrolled in 7-d replicates with a preference and a control phase. During the preference phase, the calf could choose between 4 different hutches with access to a shared paddock. Inside the hutches, either 0, 1, 2, or 3 heat lamps (HL0, HL1, HL2, HL3) were switched on. The control calf was kept in a nonheated hutch with an enclosed paddock. Calves were observed for 3 to 4 d, then switched from preference to control phase (or vice versa) and observed again for 3 to 4 d. The calves' location was documented once per minute by a time-lapse camera. Lying times and lying bouts were monitored by a 3-dimensional accelerometer data logger attached to the calves' metacarpus. With each additional heat lamp switched on, the temperature inside the hutches rose by 2.6 ± 1.0°C. Calves spent 90% of their time inside a hutch, irrespective of the number of heat lamps switched on, and no preference for a specific inside hutch temperature existed. However, we observed a tendency to prefer the location of the hutches closest to the control calf. Lying behavior did not differ between preference and control phase, but decreased marginally with increasing age. These findings could indicate a need of shelter for calves in winter, but without a preference for a certain inside hutch temperature under the prevailing conditions of deep straw bedding, highly sufficient milk supply, and an ambient temperature of 5.4 ± 3.3°C.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 4005-4015"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142942183","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":"Detection of genetic variability in dairy cattle infectivity for bovine tuberculosis","authors":"D. Madenci ,&nbsp;E. Sánchez-Molano ,&nbsp;M. Winters ,&nbsp;A. Mitchell ,&nbsp;M.P. Coffey ,&nbsp;J.D. Hadfield ,&nbsp;J.A. Woolliams ,&nbsp;G. Banos ,&nbsp;A. Doeschl-Wilson","doi":"10.3168/jds.2024-25697","DOIUrl":"10.3168/jds.2024-25697","url":null,"abstract":"<div><div>This study investigated the genetics of bovine tuberculosis (bTB) infectivity in Holstein-Friesian dairy cows using British national data. The analyses included cows with recorded sires from herds affected by bTB outbreaks between 2000 and 2022. Animals were considered bTB positive if they reacted positively to the skin test, had positive postmortem findings, or both. We introduced the “index case approach,” based on the assumption that once the initial positively tested animals (index cases) are detected in a herd, subsequent infections (secondary cases) in the early stages of the breakdown are likely to be attributed to these animals. Genetic analysis of the number of secondary cases (NrSC) associated with a given index case was used to establish evidence of genetic variability in bTB infectivity of cattle, and derive EBV for infectivity for the sires of the index cases. Data were analyzed by employing Markov chain Monte Carlo techniques to fit generalized linear mixed models with either Poisson, zero-inflated Poisson (ZIP), hurdle Poisson, or geometric distributions. All 4 models demonstrated presence of genetic variance in cattle infectivity, with the strongest evidence provided by the ZIP and hurdle Poisson models. The hurdle Poisson model offered the most accurate and least biased predictions. Sire infectivity EBV from the Poisson, ZIP, and geometric models showed strong concordance, with pairwise correlations of 0.90 or higher. In contrast, correlations between EBV from the hurdle Poisson model and the other models ranged from 0.36 to 0.39. The association of the sire infectivity EBV with the average observed NrSC per sire and the proportion of infectious index case daughters per sire was generally moderate with correlations between 44% and 47% and 65% to 69%, respectively. Agreement among models for identifying the genetically most infectious sires was also reasonable, with 151 out of 285 sires appearing in the top 10% across models, and 122 (42.8%) also aligning with the top 10% based on observed average NrSC. Results provide novel evidence for exploitable genetic variance in bTB infectivity allowing the derivation of meaningful EBV. Based on the estimated posterior mean genetic variances obtained, reduction in infectivity by 1 genetic SD would result in a 32% to 44% decrease in the expected NrSC per index case. Further research is warranted to refine the phenotypic definition of infectivity and assess correlation with other dairy traits.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 3835-3849"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142942255","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}