Journal of Dairy Science最新文献

{"title":"Dairy product and dairy iodine intake among pregnant women in 2 provinces of China: A cross-sectional study.","authors":"Ying Zhang, Wei Ma, Jianqiang Wang, Xiuwei Li, Haiyan Wang, Jinpeng Wang, Jing Xu","doi":"10.3168/jds.2024-25845","DOIUrl":"https://doi.org/10.3168/jds.2024-25845","url":null,"abstract":"<p><p>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%-23.4% of the estimated average requirement and 9.0%-16.3% of the recommended nutrient intake (RNI) of local pregnant women in the 2 provinces, respectively. Consuming 500 g of dairy products provides approximately 92.5-121.0 μg of iodine. Combined with typical iodine intake from iodized salt and other foods, this would help pregnant women meet 105%-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.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-20","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":"Enrichment of pasteurized skim milk with grape seed oil multilayer emulsions: Investigating the effect of emulsion layers on physicochemical, microbial, and sensory characteristics.","authors":"Marziyeh Sepeidnameh, Ali Fazlara, Seyed Mohammad Hashem Hosseini, Mahdi Pourmahdi Borujeni","doi":"10.3168/jds.2024-25789","DOIUrl":"https://doi.org/10.3168/jds.2024-25789","url":null,"abstract":"<p><p>Cow's milk is a nutritionally valuable food, although it lacks essential unsaturated fatty acids. Enriching milk with these fatty acids can reduce risks associated with cholesterol and saturated fats while meeting consumers' dietary needs. Grape seed oil (GSO), which is rich in omega-6 and omega-9 fatty acids, is one potential additive to replace milk fat and increase the unsaturated fat content. However, these essential unsaturated fatty acids are hydrophobic, making them difficult to dissolve in water, and are prone to oxidation, which can negatively affect the aroma and flavor of the milk. The layer-by-layer emulsion method is a promising approach to mitigate these challenges. This study investigated the enrichment of pasteurized skim milk with optimized multilayer emulsions of GSO and evaluated the physicochemical, microbial, and sensory characteristics of the milk over a storage period of 7 d at 4°C. Results indicated that single- and triple-layer emulsions remained stable within the milk matrix, but the 2-layer emulsion became unstable by d 3 of storage. During storage, acidity increased in all samples (from 0.16 to 0.44, 0.24 to 0.48, and 0.2 to 0.36 for single-, double-, and triple-layer emulsions, respectively), as did viscosity (from 1.53 to 1.9, 1.55 to 2.2, and 1.46 to 1.78 mPa·s, respectively), total microorganism count, peroxide value (from 5.52 to 17.6, 4.7 to 19.38, and 3.09 to 10.3 mEq/kg oil, respectively), and thiobarbituric acid index (from 0.43 to 0.52, 0.44 to 0.63, and 0.39 to 0.47 mg malondialdehyde/kg of oil, respectively). The pH values decreased slightly across all samples (from 6.6 to 6.5). No mold, yeast, or coliforms were detected in any sample throughout the study. Overall, the use of bioactive compounds such as essential fatty acids through milk enrichment can greatly enhance the quality of widely consumed dairy products.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143475998","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":"Targeted reproductive management for lactating Holstein cows: Reproductive and economic outcomes of Double-Ovsynch compared with a targeted approach based on resumption of estrus.","authors":"Ricardo C Chebel, Ahmadreza Mirzaei, Phillip M G Peixoto, Luana Factor, Ana B Montevecchio, Rafael S Bisinotto, Albert De Vries, Klibs N Galvão, Todd R Bilby, Kristi Jones","doi":"10.3168/jds.2024-25909","DOIUrl":"https://doi.org/10.3168/jds.2024-25909","url":null,"abstract":"<p><p>Accessibility to automated monitoring devices (AMD) has led to exploration of alternative reproductive management to ovulation synchronization protocols (OvSP) for first postpartum AI according to the cow's early postpartum estrus characteristics (EPEC). We hypothesized that pregnancy and economic outcomes of cows subjected to a targeted reproductive management (TRM) are not inferior to those of cows subjected to an OvSP for the first AI. This was a noninferiority, randomized clinical trial. Cows (n = 2,635) from one dairy were fitted with AMD and classified according to EPEC at 45 ± 3 DIM as estrual (high intensity AMD-detected estrus [primiparous: heat index ≥90, multiparous: heat index ≥70; 0 = minimum, 100 = maximum]) and anestrus (no estrus or low intensity estrus). Cows in the control treatment were enrolled in the Double-Ovsynch (GnRH on d -27, PGF_2α on d -20, GnRH on d -17 and -10, PGF_2α on d -3 and -2, GnRH on d -1, and timed AI [TAI] on d 0 at 73 ± 3 DIM). Anestrus cows enrolled in the TRM treatment were assigned to the hCG-Ovsynch (TRM1; hCG on d -17, GnRH on d -10, PGF_2α on d -3 and -2, GnRH on d -1, and TAI on d 0 at 73 ± 3 DIM). Estrual cows received PGF_2α at 60 to 73 DIM, when they were 6 to 22 d after a previous estrus, and if not inseminated in estrus within 7 d, were enrolled in the hCG-Ovsynch at 70 to 77 DIM (TRM2). Estrual cows in the TRM treatment that were ≥23 d from a previous estrus at 63 ± 3 DIM were enrolled in the hCG-Ovsynch at 63 ± 3 DIM and received TAI at 80 ± 3 DIM (TRM3). Pregnancy was diagnosed 32 ± 3 and 67 ± 3 d after AI. Cows were re-inseminated at AMD-detected estrus or at fixed time within 10 d after nonpregnancy diagnosis. The lactation gross profit was calculated as follows: (milk income + sale value + subsequent lactation calf value) - (rearing cost + feed cost + replacement cost + fixed cost + depreciation + reproductive management cost). Cows in the control treatment were more likely to be diagnosed pregnant 67 d after AI (control = 53.9% [95% CI = 51.1%, 56.6%]; TRM = 50.1% [95% CI = 47.2%, 53.0%]), independent of EPEC. The interaction between treatment and EPEC tended to affect the hazard of pregnancy throughout the lactation (control = referent; anestrus-TRM: adjusted hazard ratio = 1.01, 95% CI = 0.91, 1.13; estrual-TRM: adjusted hazard ratio = 0.83, 95% CI = 0.74, 0.94). Treatment did not affect gross profit, independent of EPEC (control = US$2,196.9 ± 25.6; TRM = US$2,221.9 ± 26.5). Alternative strategies for first postpartum AI according to a cow's EPEC may be possible with AMD, without affecting gross profit. The use of a single hCG treatment to presynchronize the estrous cycle of anestrus cows may be an alternative to the presynchronization with the Ovsynch protocol because despite slightly decreasing P/AI, it did not affect gross profit.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Invited review: Management of genetic defects in dairy cattle populations.","authors":"John B Cole, Christine F Baes, Sophie A E Eaglen, Thomas J Lawlor, Christian Maltecca, M Sofía Ortega, Paul M VanRaden","doi":"10.3168/jds.2024-26035","DOIUrl":"https://doi.org/10.3168/jds.2024-26035","url":null,"abstract":"<p><p>When related animals are mated to one another, genetic defects may become apparent if recessive mutations are inherited from both sides of the pedigree. The widespread availability of high-density DNA genotypes for millions of animals has made it possible to identify and track known defects as well as to identify and track previously unknown defects that cause early embryonic losses. Although the number of known defects has increased over time, the availability of carrier information has been used to dramatically reduce the frequency of many disorders. The economic impact of known genetic defects in the US dairy cattle population has decreased by ∼2/3 since 2016, due largely to the avoidance of carrier-to-carrier matings. Effective population management requires robust systems for reporting new defects, identification of causal mechanisms, and development of commercially available tests. The United States and Canada depend on informal cooperation among many groups, including farmers, purebred cattle associations, genetics companies, and researchers, to identify emerging and causal defects. The structure of a collaborative system including all key sectors of the dairy cattle industry to support long-term population management is described. This review provides a comprehensive overview of the landscape surrounding genetic defects in dairy cattle. Topics covered include current defects of relevance to commercial dairy producers, trends in carrier frequencies over time, how best to manage these defects, strategies for detecting emerging diseases, and marketing and trade considerations.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476036","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":"Associations between days open and dry period length versus milk production, replacement, and fertility in the subsequent lactation in Holstein dairy cows.","authors":"Michael W Overton, Steve Eicker","doi":"10.3168/jds.2024-26055","DOIUrl":"https://doi.org/10.3168/jds.2024-26055","url":null,"abstract":"&lt;p&gt;&lt;p&gt;A retrospective, observational approach was used to investigate the association between days open and dry period length in one lactation, and survivability, production, and reproductive performance in the subsequent lactation. Animal-level data from 60 intensively managed, year-round-calving US Holstein herds were collected. A subset of this larger data set was identified that also had recorded genomic test results including Dairy Wellness Profit Index (DWP$). Data from 109,374 cows comprised the larger data set (AllCows), and 37,680 cows comprised the genomics subset (GenCows). Average days open of the previous lactation (PDOPN) was 114 d, and the average dry period length (PDDRY) before the lactation of interest was 58. Response outcomes had a standard endpoint of 90 DIM of the subsequent lactation and included proportion replaced, cumulative milk production (CUM90), and proportion pregnant. Proportion replaced and proportion pregnant were analyzed using multivariable logistic regression. Milk production was analyzed using a linear mixed model. Continuous explanatory variables included previous lactation 305-d ME milk (P305ME), week-36 milk (WM36), PDOPN, PDDRY, and DWP$ (GenCows only). Categorical variables included previous lactation parity group (PLCTGP 1, 2, or 3+), calf type (female, male, or twins), and number of clinical mastitis (NMAST) or clinical lameness (NLAME) events recorded in the previous lactation. Both diseases were classified based on the number of cases recorded (0, 1, or 2+ cases). Important 2-way interactions were also considered. Increases in PDOPN were associated with increased odds of replacement, whereas the effect of PDDRY varied in a curvilinear manner, with shortest and longest PDDRY associated with highest odds of replacement. Odds of replacement increased with each increase in PLCTGP and with higher levels of recorded mastitis or lameness. Calf type was significant; delivery of twins was associated with a higher risk of replacement than a male calf. A female calf had the lowest risk of replacement than either male calf or twins. Higher P305ME was associated with lower odds of replacement. Increasing values of DWP$ were associated with reduced odds of replacement. Higher P305ME was associated with greater CUM90. Both NMAST and twins were associated with reduced CUM90. Higher DWP$ was associated with greater CUM90. The lowest PDOPN and PDDRY were associated with the highest risk of pregnancy, but the magnitude of the negative effect of PDOPN increased as PLCTGP increased. Increasing levels of P305ME had a small negative statistical association with risk of pregnancy, which is biologically insignificant. Twins, NMAST, and NLAME each had large negative effects on the odds of pregnancy by 90 DIM. Meanwhile, increases in DWP$ were associated with increased odds of achieving pregnancy. Despite significant differences between parity groups, the overall conclusion is that cows should be managed to conceive earlier ra","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143475953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of pasteurization on set yogurt fortified with astaxanthin-rich yolk: Evaluation of physicochemical properties, stability, and biological activity.","authors":"Ziwei Li, Tiehua Zhang, Runhao Zhou, Xiaoyan Zhang, Jinru Ren, Mengxue Diao","doi":"10.3168/jds.2024-26012","DOIUrl":"https://doi.org/10.3168/jds.2024-26012","url":null,"abstract":"<p><p>Pasteurization usually has a great influence on yogurt and astaxanthin. This study aimed to investigate the effects of 3 pasteurization methods, including 63°C for 30 min (LTLT-1), 65°C for 30 min (LTLT-2), and 75°C for 15 s (HTST), on the physicochemical properties, stability, and biological activity of set yogurt fortified with astaxanthin-rich yolk. The results showed that the LTLT-2 group had a higher astaxanthin retention, with no significant difference from the LTLT-1 group. The in vitro digestion results also confirmed that LTLT-2 had a high free radical scavenging capacity. Temperatures between 63°C and 65°C are within a safe range for preventing significant heat degradation of astaxanthin. Over the 21-d storage period, LTLT-2 significantly outperformed LTLT-1 and HTST regarding texture and particle size. This work demonstrates that the pasteurization conditions of 65°C for 30 min could be used to prepare a functional set yogurt with stable quality and antioxidant activity.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143475986","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":"Fermentation characteristics of Lactobacillus helveticus 3-4 and Kazachstania unispora A-3 complex starter: Enhancing the fermentation performance and flavor of koumiss.","authors":"Yanan Xia, Weigang Miao, Jianjun Zhao, Yongfu Chen","doi":"10.3168/jds.2024-26002","DOIUrl":"https://doi.org/10.3168/jds.2024-26002","url":null,"abstract":"<p><p>The flavor development of koumiss is intricately linked to its starter culture. This research aimed to delve into the microbial diversity of mare milk and koumiss, isolate the dominant lactic acid bacteria (LAB) and yeast, and assess the effects of composite strains on the fermentation characteristics and flavor quality of koumiss. In mare milk, the dominant microbial genera were Enterobacter and Rhodotorula. As fermentation progressed, the microbial diversity of mare milk gradually declined, and Lactobacillus and Dekkera became the dominant bacterial genera. A total of 42 LAB types and 24 yeast types were isolated. A 1:1 combination of Lactobacillus helveticus 3-4 and Kazachstania unispora A-3 led to a high viable bacterial count and rapid acid production in koumiss. Twenty-one flavor substances were detected, endowing the koumiss with intense umami and sour profiles. This study offers a theoretical foundation for the development and industrial application of koumiss starters.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476030","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":"Adaptation strategies to manage summer forage shortages improve animal performance and better maintain milk and cheese quality in grass- versus corn-based dairy systems.","authors":"M Bouchon, B Martin, C Bord, A Ferlay, J M G Bloor, M Eugène, A Delacroix-Buchet, C Cebo, M C Michalski, B Graulet, I Verdier-Metz, C Delbes","doi":"10.3168/jds.2024-25730","DOIUrl":"https://doi.org/10.3168/jds.2024-25730","url":null,"abstract":"<p><p>In semi-mountainous grass-based dairy systems, summer droughts frequently reduce grass availability, with implications for animal performance as well as milk and cheese quality. The objective of our study was to investigate the effect of a simulated summer forage shortage in a traditional semi-mountainous grass-based system versus a corn-based system with part-time grazing. During a 19-wk experiment, 26 Holstein and 14 Montbéliarde cows were blocked in 4 balanced groups of 10 cows. During the first 8 wk, 2 groups were fed a grass-based diet (75% of grazed grass, 25% of hay and concentrates) and the remainder were fed a corn-based diet (75% mixed ration, 25% of grazed grass). During the following 11 wk, one group in each feeding system was subjected to a reduction in grazed grass intake and a corresponding increase in indoor feeding, resulting in 50% of grazed grass for grass-fed cows and removal of grazed grass for corn-fed cows. Milk yield and composition were recorded during the whole trial, in addition to indoor individual intake. Grass intake was modeled to calculate feed efficiency and estimate methane emissions. At the end of the experiment, bulk milk from each group was sampled for physicochemical and microbiological analyses and processed into Cantal-type cheeses. After 9 weeks of ripening, cheeses underwent physicochemical, microbiological and descriptive sensory analyses. Results showed that the complete removal of grazed grass in corn-based system had no effect on milk production but impaired feed efficiency; grass reduction in the grass-based diet better maintained milk yield, enhanced feed efficiency, and reduced methane emission intensity. Cheese softness increased with proportion of grass in the diet, and it was positively correlated with primary proteolysis (α_S1-casein and β-casein breakdown) but negatively correlated with the C16:0/C18:1 ratio and the calculated fat melting point. Cheese from cows fed with more grazed grass were the yellowest and had the most pronounced flavors, as well as higher counts of heterofermentative lactobacilli and lactic acid bacteria. Removal of grazed grass from the corn-based diet led to cheese that was less yellow and had less flavor, in line with lower levels of secondary proteolysis. In conclusion, our study suggests that maintaining fresh herbage in corn-based diets is crucial for maintaining cheese quality without impairing animal performance. In grass-based systems, complementation with indoor feeding may have limited effects on product quality but promotes the maintenance of animal performance.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143475952","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 farm management factors associated with clinical observations in young dairy calves sold at auction markets in Québec, Canada: A cross-sectional study.","authors":"Sébastien Buczinski, Gilles Fecteau, Anne-Sophie Perrault, Salvatore Ferraro, Julie Arsenault, Younes Chorfi, Marcio Costa, Jocelyn Dubuc, David Francoz, Marjolaine Rousseau, Marianne Villettaz-Robichaud","doi":"10.3168/jds.2024-26118","DOIUrl":"https://doi.org/10.3168/jds.2024-26118","url":null,"abstract":"&lt;p&gt;&lt;p&gt;In Québec, Canada, nonreplacement calves are generally sent at a young age to auction markets to be sold for veal or dairy beef production. Various clinical observations found during the calves' journey, either at an auction market or on arrival at a calf raiser farm, have been associated with increased risk of morbidity, such as dehydration or umbilical problems. The objective of this cross-sectional study was to quantify associations between calf raising management strategies at the dairy farm level and clinical observations at auction markets during sale. For this purpose, during 8 different sale days, the 2 largest auction markets in Québec were visited, and all calves sold on those days were systematically examined. The number of clinically relevant findings (CRF) present per calf (among presence of umbilical cord, wet umbilical area, umbilical pain, umbilical swelling, persistent cervical skin fold ≥2 s, sunken eyes, eye or nasal discharge, ear drop, limb anomaly, emaciation or dirty hide) was recorded. After the sale, farm owners were contacted to answer a specific questionnaire on calf management. The total number of CRF from all sold calves from the same farm (dependent variable) was modeled using Poisson multivariable regression, with questionnaire answers as potential covariates and the number of calves sold per farm during the observation period as an offset. The questionnaire was completed during a standardized phone call and focused on farm characteristics and characteristics of calves sold, including calving management, calf care at birth, nutrition, housing, and transportation. A total of 3,656 calves from 1,349 different sellers were examined. The questionnaire information was obtained from 409 different farms representing 847 calves. The median number of calves sold per farm was 2 (range: 1-19). The umbilical cord was visually present in 376 calves (44%). Among the most commonly observed CRF, eye discharge (n = 290, 34%), umbilical swelling (n = 144, 17%), and presence of dehydration signs (persistent cervical skin fold ≥2 s [n = 111, 13%] or sunken eyes [n = 83, 9.8%]) were the most commonly reported anomalies. According to the final multivariable Poisson regression model, the incidence rate ratio (IRR) of CRF for farms that sold calves at a mean age &lt;8 d was higher than for farms that sold calves at a mean age of &gt;10 d (IRR = 1.21, 95% CI: 1.04-1.41). The IRR was also higher for farms that did not give colostrum to calves within 1 h following birth compared with calves receiving colostrum within 1 to 2 h (IRR = 1.73, 95% CI: 1.24-2.49), 2 to 6 h (IRR = 1.48, 95% CI: 1.06-2.14) and more than 6 h (IRR = 1.59, 95% CI: 1.06-2.44) after birth. The IRR were higher for farms using milk replacer to feeding sold calves versus raw milk (IRR = 1.2, 95% CI: 1.06-1.37) and higher for farms where calves typically receive their last meal &gt;3 h before transportation to the auction market versus calves receiving their last meal &lt;1 h befor","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143475965","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":"Effect of 10 freshwater microalgae on in vitro methane mitigation and rumen fermentation.","authors":"Yang Li, Mariluz Bagnoud-Velásquez, Yixin Zhang, Kai Wang, Lenka Punčochářová, Carmen Kunz, Sebastian Dubois, Rong Peng, Alexandra Baumeyer Brahier, Fabian Wahl, Mutian Niu","doi":"10.3168/jds.2024-25749","DOIUrl":"https://doi.org/10.3168/jds.2024-25749","url":null,"abstract":"<p><p>Agriculture is at the pivot point between anthroposphere, biosphere, and atmosphere. Innovative solutions are needed to reduce agricultural emissions and improve sustainability. Microalgae animal feed could be such a solution. This study aimed to evaluate the effects of 10 freshwater microalgae: Auxenochlorella protothecoides, Chlamydomonas pulvinate, Chlorella luteoviridis, Chlorella variabilis, Euglena mutabilis, Parachlorella kessleri, Stichococcus bacillaris, Tetradesmus acuminatus, Tetradesmus obliquus, and Tetraselmis gracilis, on ruminal methane (CH₄) production, nutrient digestibility, and rumen fermentation using the in vitro Hohenheim gas test. The microalgae were cultured in a carbon dioxide (CO₂) incubator at 2% CO₂, at the optimal conditions for each strain. The highest producers were P. kessleri and T. obliquus, with a biomass concentration of 0.69 and 0.73 g/L·d, respectively. Their PUFA contents ranged from 33.2 to 69.1 of total fatty acids. Microalgae were tested at a 15% replacement in a control basal diet of 40.0% DM grass silage, 40.0% maize silage, 15% hay, and 5% concentrate. Data were analyzed using a mixed model in R. Ruminal CH₄ production was reduced by 15.4%, 17.4%, and 16.4% in diets containing A. protothecoides, C. luteoviridis, and P. kessleri, respectively, compared with the control diet. Similarly, these diets reduced in vitro organic matter digestibility by 3.5%, 5.2%, and 5.4%, respectively. However, only A. protothecoides reduced CH₄/CO₂ ratio by 3.5% compared with the control diet. Propionate molar proportion was decreased by 2.4, 3.0, 2.5, and 2.5%pt for diets containing C. pulvinate, E. mutabilis, P. kessleri, and T. obliquus, respectively. Marginal effects of dietary variables were analyzed using the generalized additive model framework, revealing a negative relationship between dietary PUFA, sulfur content, and CH₄ production, and a negative relationship between dietary PUFA and CH₄/CO₂ ratio. Incorporating high-PUFA microalgae in ruminant diets shows potential for reducing enteric CH₄ emissions, warranting further investigation.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143475969","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}