JDS communications最新文献

{"title":"Bacillus spp. supplementation promotes feed efficiency in mid- to late-lactation dairy cows and affects rumen fermentation traits of rumen-fistulated females offered a corn silage–based total mixed ration diet","authors":"Bruno A.V. Arthur ,&nbsp;Luiz Gustavo Nussio ,&nbsp;Oscar C.M. Queiroz ,&nbsp;Greicieli de Morais ,&nbsp;Rafael H.P. Reis ,&nbsp;Giuseppe Copani ,&nbsp;Jens N. Joergensen ,&nbsp;Bruno I. Cappellozza","doi":"10.3168/jdsc.2024-0686","DOIUrl":"10.3168/jdsc.2024-0686","url":null,"abstract":"<div><div>Two experiments evaluated the effects of supplementing a <em>Bacillus</em>-based direct-fed microbial (DFM) on productive performance of mid- to late-lactating dairy cows (experiment [Exp.] 1), and on rumen fermentation traits of rumen-fistulated Holstein cows (Exp. 2). In Exp. 1, 60 mid-lactating (126 ± 11.5 DIM), primiparous (n = 14), and multiparous (n = 46) Holstein cows were blocked, within parity, by milk yield into (1) TMR (CON; n = 30) and (2) CON with <em>Bacillus licheniformis</em> 809 and <em>Bacillus subtilis</em> 810 (n = 30; BAC). Diets were offered for 12 wk, following a 3-wk covariate period. All cows received a corn silage–based TMR throughout the study. Dry matter intake and milk yield were evaluated daily, whereas milk, blood, and fecal samples were collected on wk 4, 8 and 12 for milk composition, metabolite analysis (urea and glucose), and nutrient digestibility, respectively. In Exp. 2, 16 rumen-fistulated nonlactating multiparous Holstein cows were ranked by initial BW and assigned to the treatments described in Exp. 1. The experimental period lasted 25 d and samples were taken on d 22 to 25 for in situ DM degradability, rumen ammonia, and pH. All data were analyzed with the MIXED procedure of SAS using cow as the experimental unit. In Exp. 1, DMI was reduced in BAC-fed cows, but no differences were observed on milk yield. Cows offered BAC had a grater feed efficiency versus CON (+100 g/kg feed). <em>Bacillus</em> spp. supplementation increased milk fat content, reduced MUN, and tended to reduce milk protein content. Mean BUN was reduced and plasma glucose was greater in cows fed BAC. No treatment effects were observed for DM or starch digestibility, but NDF digestibility was greater for BAC-fed cows. In Exp. 2, a treatment × hour interaction was observed on DM degradability, being greater at 12 h postfeeding in BAC cows versus CON. Rumen pH tended to be greater for BAC at 12, 24, and 72 h, whereas mean rumen pH and DM degradability were greater in BAC. In summary, feeding a <em>Bacillus</em>-based DFM to mid- to late-lactating dairy cows improved feed efficiency and increased mean glucose, while also stimulating DM and NDF digestibility.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"6 4","pages":"Pages 490-496"},"PeriodicalIF":0.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518032","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}

{"title":"Effect of forage sorghum hybrids varying in berry size on berry processing score and in situ starch digestibility","authors":"Douglas Duhatschek ,&nbsp;Jourdan Bell ,&nbsp;Luiz F. Ferraretto ,&nbsp;Diego Duretto ,&nbsp;John Goeser ,&nbsp;Elizabeth Coons ,&nbsp;Jason K. Smith ,&nbsp;Sushil Paudyal ,&nbsp;Juan M. Piñeiro","doi":"10.3168/jdsc.2025-0749","DOIUrl":"10.3168/jdsc.2025-0749","url":null,"abstract":"<div><div>Water scarcity threatens the production of forages used to feed lactating dairy cows. Utilizing water efficient crops is key for dairy farms trying to mitigate drought and forage scarcity risks. Forage sorghum is a water-efficient crop with the potential to partially replace corn silage. However, challenges with processing forage sorghum berries have resulted in poor starch digestibility and decreased milk production of lactating dairy cows compared with those fed with corn silage. Consequently, this has prevented its adoption by dairy farmers. The objective of this study was to evaluate if a 1.70-mm berry processing score (BPS_1.70) and ruminal in situ starch digestibility at 7 h (isSD7) would increase when harvesting forage sorghum with larger berry size compared with regular berry sized hybrid. Two forage sorghum hybrids (F10 and F24) were seeded in 5 plots blocked by the spans across the center irrigation pivot in a randomized complete block design. The F10 hybrid had average size berries; only 41.7% of intact berries were retained above a 3.35-mm sieve. Conversely, the F24 hybrid was genetically developed to produce a larger whole berry size and retained 90% of intact berries above a 3.35-mm sieve. With larger berries, the proportion of starch for the F24 increased almost 3 percentage units compared with F10 (26.6% and 23.9%, respectively). However, BPS_1.70 and isSD7 were not different. The study suggests that although increasing berry size may increase starch content, it does not necessarily increase BPS_1.70 and isSD7, at least for the berry size difference tested and harvested with kernel processors and settings commonly used to process corn.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"6 4","pages":"Pages 513-517"},"PeriodicalIF":0.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518036","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}

{"title":"Effects of lysophosphatidylcholine on the oxidative burst response, inflammatory cytokine secretion, and Escherichia coli killing in polymorphonuclear neutrophils isolated from Holstein heifer calves","authors":"B.N. Tate ,&nbsp;A. Zhu ,&nbsp;M.J.B. Felippe ,&nbsp;D.C. Reyes ,&nbsp;J.W. McFadden","doi":"10.3168/jdsc.2024-0646","DOIUrl":"10.3168/jdsc.2024-0646","url":null,"abstract":"<div><div>The neonatal bovine immune system is immunonaïve at birth, making newborn calves reliant on passive immunity acquired through colostrum for protection. Calfhood illness can negatively affect health and productivity in adulthood, leading to economic losses and welfare concerns within the cattle industry. Lysophosphatidylcholine (LPC) is an immunomodulator known for enhancing bactericidal mechanisms in immune cells. However, the role of LPC in ruminants has not been thoroughly investigated. Our objective was to determine whether LPC modulates neonatal bovine neutrophil activation, cytokine release, and <em>Escherichia coli</em> killing. Neutrophils were isolated from the peripheral blood of preweaning Holstein heifer calves. The effects of LPC on hydrogen peroxide (H₂O₂) production, tumor necrosis factor-α, and IL-6 secretion, and <em>E. coli</em> killing were evaluated. Each experiment used 3 calves, with biological and technical replicates performed in duplicate. Data were analyzed using a mixed linear model including the fixed effects of treatment and time (when applicable) and the random effect of calf and replicate nested within treatment. In bovine neutrophils, palmitoyl-, stearoyl-, and oleoyl-LPC (i.e., LPC-16:0, -18:0, and -18:1, respectively) enhanced phorbol myristate acetate-stimulated H₂O₂ production. Additionally, LPC-18:0 potentiated lipopolysaccharide-induced tumor necrosis factor-α and IL-6 secretion. Although LPC-18:1 did not demonstrate this effect, LPC-18:0 was found to enhance neutrophil-mediated <em>E. coli</em> killing. We conclude that stearoyl-LPC enhances neutrophil bactericidal mechanisms and inflammatory responses in dairy calves. Additionally, palmitoyl- and oleoyl-LPC contribute to increased H₂O₂ production. These findings indicate that LPC plays an important role in modulating various neutrophil functions in neonatal bovine immunity.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"6 4","pages":"Pages 583-588"},"PeriodicalIF":0.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517906","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}

{"title":"Induction of intestinal barrier dysfunction in dairy heifers: Evaluation of new serum inflammatory markers and method for quantifying intestinal hyperpermeability","authors":"K.E. Vagnoni,&nbsp;E. Lopez-Cruz,&nbsp;M. Carranza,&nbsp;D.B. Vagnoni","doi":"10.3168/jdsc.2025-0740","DOIUrl":"10.3168/jdsc.2025-0740","url":null,"abstract":"<div><div>Experimental induction of intestinal barrier dysfunction (e.g., inflammation and hyperpermeability) has been shown to induce a systemic inflammatory response and reduce productivity in lactating dairy cows. Because numerous natural situations on-farm (e.g., ruminal acidosis, heat stress, weaning) can impair intestinal barrier function, this is an important phenomenon to study. Therefore, our objective was to induce intestinal barrier dysfunction and evaluate new serum inflammatory markers as well as a new approach to measuring intestinal hyperpermeability. This was accomplished via oral aspirin administration for 21 d in 10-mo-old Holstein and Jersey heifers. Twelve heifers (6 each, Holsteins and Jerseys) were blocked by breed and then randomly assigned (3 heifers per breed) to receive either 0 or 200 mg aspirin/kg BW per day orally. At 0600 h on d 21 of the experiment, urine and blood samples were collected from each animal. Heifers then were dosed orally with gelatin capsules containing 50 g of Co-EDTA using a balling gun. Urine samples were subsequently collected at 1, 3, 6, 8, 12, 18, 24, 30, and 36 h after dosing. Urine samples were analyzed for Co and creatinine, and serum samples were analyzed for the inflammatory markers haptoglobin (Hp), LBP, FABP2, and TNF. Modeling urinary Co:creatinine ratios using a nonlinear function yielded an excellent fit and indicated that urinary Co excretion, a measure of intestinal permeability, was not increased due to aspirin but was higher for Jersey than for Holstein heifers. Also, serum concentrations of Hp and LBP were unaffected, but serum concentrations of FABP2 and TNF were increased due to aspirin administration. Finally, analysis of covariance indicated that serum TNF concentrations were highly correlated with urinary Co excretion. These data suggest that FABP2 and TNF may be valuable additional markers for the study of intestinal barrier dysfunction.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"6 4","pages":"Pages 593-597"},"PeriodicalIF":0.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517907","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}

{"title":"Relationship between cow parity and maternal parity on dairy cow lactation performance","authors":"D.P. Berry ,&nbsp;K. Downing","doi":"10.3168/jdsc.2025-0775","DOIUrl":"10.3168/jdsc.2025-0775","url":null,"abstract":"<div><div>The effect of dam parity on the subsequent performance of her female progeny is of interest when exploring the cost-benefit of alternative herd-level breeding strategies. This is especially true with the growing adoption of sexed semen where proportionally more of the heifers and younger cows in a herd may be selected as candidate dams of the next generation. There is a paucity of information on the effect of, or association between, dam parity and subsequent progeny lactation productivity in dairy cows. The objective of the cross-sectional analysis of 1,833,875 cow lactation records in the present study was to quantify the association between dam parity (1 to 10+) and subsequent progeny lactation yield, milk fat and protein concentration, and SCC. Also of interest were model cow parity effects for these traits so as to inform cost-benefit analyses of improving cow lifespan. All associations were estimated using linear mixed models with cow included as a random effect while also facilitating heterogeneous dam and cow parity variance components. Mean yield increased with cow parity up to parity 5 (30% to 33% higher than yields from first parity cows) after which it declined; parity 10+ cows still produced, on average, 19% to 21% more milk than first parity cows although mean lactation SCC increased with advancing parity in multiparous cows. The mean 305-d lactation milk yield of cows increased as the parity number of their dams increased, peaking at parity 7 (19.8 kg more milk than progeny from first lactation dams) before declining. In contrast, peak fat and protein yields occurred at younger dam parities. Although the mean SCS of cows was greatest in progeny from parity 2 dams, mean lactation SCS declined thereafter as dam parity number increased. In conclusion, although dam parity was associated with progeny lactation performance, the biological extent of this association was almost negligible.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"6 4","pages":"Pages 544-547"},"PeriodicalIF":0.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517982","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}

{"title":"Evaluating bacterial growth in raw, frozen, and heat-treated colostrum inoculated with fecal Escherichia coli","authors":"A.M. McKane,&nbsp;T.A. Westhoff,&nbsp;S. Klaessig,&nbsp;C. Altier,&nbsp;K.E. Bell,&nbsp;P.D. Pavinski Bitar,&nbsp;S. Mann","doi":"10.3168/jdsc.2025-0756","DOIUrl":"10.3168/jdsc.2025-0756","url":null,"abstract":"<div><div>Providing newborn calves with sufficient high-quality colostrum is a critical calf-management strategy to support health, survival, and future productivity. Unfortunately, colostrum may also serve as a fomite for disease when contaminated with bacteria at harvest, during storage, or during reheating before feeding. Thermal processing, including heat treatment (HT; 60°C for 60 min) and freezing (FR; −20°C), are common strategies to manage bacterial contamination. Although both strategies maintain IgG concentrations, they destroy colostral immune cells, and HT is known to decrease the concentration and activity of certain bioactive factors such as complement and IgA. We hypothesized that HT and FR would influence the inherent antibacterial properties of bovine colostrum compared with unprocessed, refrigerated colostrum (RW). Our objective was thus to compare growth of <em>Escherichia coli</em> in RW, HT, and FR bovine colostrum. Sterile colostrum samples were collected from Holstein cows (n = 11) on a commercial dairy in New York State and divided into 4 aliquots. One aliquot was submitted for bacterial culture to exclude samples with any bacterial growth (n = 4). The remaining 7 samples were used for the experiment. Aliquots were either RW (4°C for 20 h; n = 7), HT (60°C for 60 min, then 4°C for 19 h; n = 7), or FR (−20°C for 20 h; n = 7). Immediately before inoculation of samples for a bacterial kinetics assay, a dried bovine colostrum-based replacer (CR; Ultra Start 150, Sav-A-Calf, Chilton, WI) was prepared from a single bag according to package instructions as a nutrient-rich control (n = 7). The prepared CR aliquots underwent bacterial culture to ascertain the absence of bacterial growth before inoculation. To simulate contamination that may occur on-farm, all samples were inoculated with 10⁴ cfu/mL <em>E. coli</em> (WM1; 060913 P0lA, isolated from bovine feces) and tested in a bacterial kinetics assay at 37°C. At 0, 2, 4, 6, 8, and 24 h, growth of <em>E. coli</em> was quantified on MacConkey agar plates inoculated at 37°C. Relative to colostrum replacer, growth of <em>E. coli</em> was lower in RW and FR colostrum from 4 to 24 h and lower in HT colostrum at 6 and 8 h. These results demonstrate inherent microbial growth-inhibiting activity in RW colostrum and suggest that FR better preserved this activity than HT. Our study contributes to understanding the effect of thermal processing on antimicrobial properties of colostrum with the goal of helping to inform colostrum-management strategies for dairy producers. Specifically, our data emphasizes the need to practice hygiene during all steps of the colostrum harvest and storage process, including after completion of HT, because this renders colostrum more susceptible to bacterial growth. Similarly, the cooling and heating steps of stored colostrum should be rapid to minimize growth of <em>E. coli</em>.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"6 4","pages":"Pages 552-556"},"PeriodicalIF":0.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517984","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}

{"title":"Validation of a rapid on-farm culture system for group classification of clinical mastitis-causing pathogens","authors":"Fernando J. Guardado Servellon ,&nbsp;David L. Renaud ,&nbsp;Bruno Joaquin Paredes Osorio ,&nbsp;Kelsey L. Spence ,&nbsp;Trevor J. DeVries ,&nbsp;Rita Couto Serrenho","doi":"10.3168/jdsc.2024-0738","DOIUrl":"10.3168/jdsc.2024-0738","url":null,"abstract":"<div><div>The objective of this diagnostic accuracy study was to compare the use of a rapid tube test system (MastDecide [MD]; Quidee GmbH, Homberg, Germany) to aerobic milk culture for group classification of mastitis pathogens in dairy cattle. A total of 204 milk samples from cows with clinical mastitis (CM) were collected across 60 dairy herds in Ontario, Canada. Samples were collected by dairy producers and their staff and transported refrigerated to the University of Guelph Animal Health Laboratory (Guelph, ON, Canada) on the day of collection. Each sample was tested via MD (gram-positive, gram-negative, or “no growth”) and via aerobic milk culture followed by MALDI-TOF (reference method [RM]). The MD and RM results were interpreted at 14 and 24 h after incubation, respectively. An additional assessment was performed regarding the accuracy of intramammary antibiotic treatment decisions (gram-positive: to treat; gram-negative and “no growth” samples: not to treat). Test performance characteristics (overall accuracy, sensitivity [Se], specificity [Sp], and positive [PPV] and negative predictive value [NPV]) as well as Cohen's kappa coefficient (κ) were calculated. The RM results were classified as gram-positive (n = 107, 53%), gram-negative (n = 20, 10%), “no growth” (n = 51, 25%), other pathogens (n = 21, 10%), and mixed growth (gram-positive and gram-negative; n = 5, 3%). The Se of the MD test was 58% (95% CI: 47%–67%), 40% (19%–64%), and 61% (50%–72%) for gram-positive, gram-negative, and “no growth,” respectively. The Sp of the MD test was 73% (63%–81%), 84% (78%–89%), and 75% (66%–82%) for gram-positive, gram-negative, and “no growth,” respectively. The PPV of the MD test was 68% (57%–78%), 22% (10%–39%), and 62% (50%–73%) for gram-positive, gram-negative, and “no growth,” respectively; and the NPV was 63% (54%–72%), 93% (87%–96%), and 74% (65%–82%) for gram-positive, gram-negative, and “no growth,” respectively. The overall test accuracy for Gram stain classification analysis was 57%, with a κ of 0.30. Regarding intramammary antibiotic treatment, the MD test yielded a correct decision relative to the RM for 65% of the cases. Using this on-farm test as a primary guide in CM treatment decisions should be approached with caution, as the risk of false negatives may affect the ability to effectively treat CM cases.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"6 4","pages":"Pages 562-566"},"PeriodicalIF":0.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517986","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}

{"title":"Skimming and storage factors affect the detection of heat shock protein 70 in raw bovine milk","authors":"M.R.H. Rakib ,&nbsp;V. Messina ,&nbsp;J.I. Gargiulo ,&nbsp;N.A. Lyons ,&nbsp;I.N. Pathirana ,&nbsp;P.C. Thomson ,&nbsp;S.C. Garcia","doi":"10.3168/jdsc.2025-0759","DOIUrl":"10.3168/jdsc.2025-0759","url":null,"abstract":"<div><div>Heat shock proteins (HSP) play a vital role in maintaining cellular function under elevated temperatures. Among these, heat shock protein 70 (HSP70) has recently been detected in bovine milk using competitive ELISA, highlighting its potential as a noninvasive marker of cellular stress and a tool for detecting heat stress (HS) in dairy cows. However, optimal management and storage conditions of milk samples for detection of HSP70 are yet to be determined. This study aimed to evaluate how different management and storage practices affect detection of HSP70 in milk samples. Samples were skimmed by centrifugation either before storage (SBS) or after storage (SAS), and then stored under different temperatures: (a) room temperature (T₁, ∼22°C), (b) refrigerated (T₂, 4°C), (c) frozen (T₃, −20°C), and (d) refrigerated at 4°C with a preservative (bronopol; T₄). Samples were analyzed every 2 d until d 15 (d 1, d 3, …, d 15) using a competitive ELISA system (sensitivity range 31.25–2,000 ng/mL) to detect HSP70 levels. Result showed that SBS samples had the smallest reduction in HSP70 levels on d 3 when stored at T₂ or T₃, with decreases of 4.4% and 7.9%, respectively. In contrast, SAS samples exhibited greater reductions (44.2% at T₂ and 53.9% at T₃). Samples stored at room temperature (T₁) showed the greatest degradation, especially in SAS samples, whereas the use of a preservative (T₄) did not consistently maintain HSP70 levels in either SBS or SAS samples. The HSP70 detection showed lower variability during early storage (d 1–3) across all treatments, with SBS samples demonstrating greater stability than SAS; however, variability significantly increased by d 9 in both sample types. An apparent increase in HSP70 levels was observed from d 11 to 15 in both SBS and SAS, suggesting the influence of protein stability and interactions affecting ELISA reactivity, where further research is required. Overall, samples stored as skim milk until d 3 at 4°C or −20°C preserved HSP70 levels more effectively than whole milk, with room temperature storage being the least favorable. This pioneering study explored how sample storage and management affect HSP70 detection, providing practical guidelines for farmers and processors to preserve milk sample integrity for assessment of HSP70 as indicator of cellular stress and, potentially, HS.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"6 4","pages":"Pages 578-582"},"PeriodicalIF":0.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517905","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}

{"title":"Effects of large follicle numbers at the onset of short-term timed artificial insemination protocol in lactating dairy cows","authors":"Kazuhiro Bandai ,&nbsp;Ena Chiba ,&nbsp;Toru Ogata ,&nbsp;Yoshiyuki Tsuchiya ,&nbsp;Tadaharu Ajito ,&nbsp;Ryotaro Miura","doi":"10.3168/jdsc.2024-0682","DOIUrl":"10.3168/jdsc.2024-0682","url":null,"abstract":"<div><div>This study aimed to compare the fertility of lactating Holstein cows with only 1 large follicle (LF, diameter ≥10 mm) with those with ≥2 LF and corpora lutea at the start of short-term ovulation synchronization and timed artificial insemination (AI). Cows with a corpus luteum ≥20 mm in diameter and either 1 LF (1F) or ≥2 LF (2F) verified via ovarian ultrasonography were included in the study. Cows were randomly categorized into groups receiving either estradiol benzoate (EB) or GnRH as ovulation induction agents. Cows received a luteolytic dose of PGF_2α, followed by administration of EB 24 h later or GnRH 56 h later. Timed AI was performed 24 to 28 h after EB administration or 16 to 20 h after GnRH administration. We analyzed data from 605 AI in 554 cows (1F-EB: n = 193, 2F-EB: n = 100, 1F-GnRH: n = 213, 2F-GnRH: n = 99). Logistic regression analysis revealed a significant interaction between the number of LF and the ovulation induction agent. Pregnancy per AI was significantly lower in the 1F-GnRH group than in the other 3 groups (1F-EB: 40.9%, 2F-EB: 44.0%, 1F-GnRH: 28.2%, 2F-GnRH: 44.4%). In conclusion, the fertility of cows with 1F was lower than that of cows with 2F when GnRH was administered as the ovulation induction agent in the ovulation synchronization and timed AI protocol. However, the fertility of 1F cows receiving EB was comparable to that of 2F cows receiving either GnRH or EB.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"6 4","pages":"Pages 589-592"},"PeriodicalIF":0.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517957","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}

{"title":"Factors affecting follicular emergence at 10 days postpartum in lactating dairy cows","authors":"Hiromi Kusaka ,&nbsp;Takeshi Yamazaki ,&nbsp;Minoru Sakaguchi","doi":"10.3168/jdsc.2025-0744","DOIUrl":"10.3168/jdsc.2025-0744","url":null,"abstract":"<div><div>Several factors influence postpartum ovarian activity in dairy cows. Our previous research confirmed a significant seasonal effect on the occurrence of early ovulation until 26 d postpartum, yet the relationships with earlier follicular development were not examined. This retrospective study aimed to describe the association between follicular development at 10 d postpartum and the presence of early ovulation in 536 lactations. Furthermore, the factors affecting the emergence of ≥15 mm (LL-size) of follicles at 10 d postpartum were assessed, including calving season, parity of dams, BW loss, period of years, number of calves, and uterine abnormality. Approximately 12% of cows lacked ≥10.0 mm follicles at 10 d postpartum and had a lower frequency of early ovulation (32.3%). Early ovulation was observed more in cows with at least one LL-size but no 10.0 to 14.9 mm follicles (69.7%). The odds ratio of LL-size follicle presence in the cows with high uterine abnormalities was significantly lower than in the cows with low uterine abnormalities (odds ratio: 0.20, 54.0% vs. 83.5%). Fewer &lt;10.0 mm follicles were detected in the former than the latter. The cows that calved in summer had a higher frequency of LL-size follicles than those that calved in winter and spring. The effects of BW loss and dam parity on the presence of LL-size follicles approached significance. In conclusion, calving season, BW loss, and dam parity influenced the likelihood of LL-size follicle emergence. In particular, an abnormal uterine status 10 d after calving inhibited early follicular development, which might affect early ovulation.</div></div>","PeriodicalId":94061,"journal":{"name":"JDS communications","volume":"6 4","pages":"Pages 598-603"},"PeriodicalIF":0.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517908","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}