Journal of Dairy Science最新文献

{"title":"Association of sire net merit with farm profitability for Minnesota dairy farms.","authors":"R L Weir, I W Haagen, C E Ambrozek, C D Dechow, J C Hadrich","doi":"10.3168/jds.2024-25922","DOIUrl":"https://doi.org/10.3168/jds.2024-25922","url":null,"abstract":"<p><p>Lifetime net merit (NM$) is a genetic selection index based on the weighted average of economically relevant traits to the dairy cow. It is measured in dollars as the expected lifetime profitability of a cow. The objective of this study was to evaluate the association between average sire net merit management decisions and farm profitability for Minnesota dairy farms from 2012 to 2018 using a unique herd-year dataset (n = 227) containing production data for dairy cows, sire NM$, and the respective financial information for the farm. We extended the net merit and profitability analysis by analyzing the individual net merit traits that might be driving profitability. Ordinary least squares models were estimated for 4 profitability measures: operating profit margin, rate of return on assets (RROA), net farm income (NFI), and NFI per cow. Results indicated that herd sire net merit has a positive and significant relationship with RROA, NFI, and NFI per cow. A $100 increase in the herd's sire net merit was associated with an 18% (0.6 percentage point) increase in RROA, $12,100 increase in NFI, and $87 increase in NFI per cow, all else equal. Although the genetic association was significant, it explained 3.62% or less variation, highlighting that herd genetics were not the primary factor driving profitability. A few of the individual net merit traits held a significant relationship with profit, but most of the individual net merit traits did not. We concluded that it is not individual traits that influenced profitability, but rather the collective group of traits. The results from this study suggested that decisions related to genetic selection are valuable for a farm's profit and confirmed that when selecting genetics, it was most effective to select sires based on an economic index, rather than specific traits.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143953138","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":"Simultaneous quantitative detection of viable Salmonella spp., Shiga toxin-producing Escherichia coli, Bacillus cereus, and Listeria monocytogenes in milk through multiplex real-time PCR.","authors":"Peilin Liu, Chenpeng Shi, Yanwei Wang, Huiming Gao, Shan Wang, Pengfei Ai","doi":"10.3168/jds.2025-26278","DOIUrl":"https://doi.org/10.3168/jds.2025-26278","url":null,"abstract":"<p><p>In our study, a multiplex real-time polymerase chain reaction (mRT-PCR)-based method was established to detect viable Salmonella spp. (SS), Shiga toxin-producing Escherichia coli (STEC), Bacillus cereus (BC), and Listeria monocytogenes (LM) simultaneously in milk samples. The oligonucleotide sequences of the target genes invA from SS, stx1 from STEC, entFM from BC, and mpl from LM were used for primer and probe design. To eliminate false-positive results, the bacterial samples, containing live and partially dead bacterial cells, were treated with 300 μM of sodium dodecyl sulfate (SDS), followed by 20 μM of propidium monoazide (PMA). The optimized SDS-PMA-mRT-PCR (SPMP) method exhibited a 10² cfu/mL detection limit for the 4 target bacteria, similar to the accuracy of the plate count method. Our findings suggest that the developed SPMP method can rapidly detect viable SS, STEC, BC, and LM in milk samples within 7 h.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143967264","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":"In utero heat stress compromises whole-body growth and mammary development from postweaning through puberty.","authors":"Brittney D Davidson, Sena L Field, Bethany Dado-Senn, Adam D Beard, Pedro L J Monteiro, Kaylee A Riesgraf, Anne R Guadagnin, Milo C Wiltbank, Geoffrey E Dahl, Jimena Laporta","doi":"10.3168/jds.2025-26458","DOIUrl":"https://doi.org/10.3168/jds.2025-26458","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Late-gestation in utero heat stress derails organ development and growth, leading to reduced first-lactation milk yield. Yet, carry-over effects of in utero heat stress on peripubertal heifers remain unexplored. This study investigated the long-term effects of in utero heat stress on body growth, mammary gland (MG) development, and ovarian function in peripubertal heifers. Dry, pregnant cows were housed in freestall barns and provided only shade or shade plus evaporative cooling for the last 54 ± 5 d of gestation during a subtropical summer. The resulting in utero cooled (IUCL, n = 21) and in utero heat-stressed heifers (IUHT, n = 19) were raised as a single cohort until 12 mo of age. Body weight, hip height (HH), chest girth (CG), body length (BL), withers height (WH), head circumference (HC), and MG macrostructure was recorded monthly from 3 to 12 mo. Once puberty was confirmed with 2 consecutive weeks of plasma progesterone (P&lt;sub&gt;4&lt;/sub&gt;) concentrations &gt;1 ng/mL, heifers were assigned to a protocol for the synchronization of estrus (D-7: GnRH + CIDR, D-2: PGF&lt;sub&gt;2α&lt;/sub&gt;, D-1: PGF&lt;sub&gt;2α&lt;/sub&gt; + CIDR removal). Blood and MG biopsies were collected on d 0 (high estradiol [E&lt;sub&gt;2&lt;/sub&gt;]/low P&lt;sub&gt;4&lt;/sub&gt;) and d 13 (low E&lt;sub&gt;2&lt;/sub&gt;/high P&lt;sub&gt;4&lt;/sub&gt;) to quantify mammogenic hormones and MG microstructure. Ovarian ultrasounds were conducted on d 0, 9, and 13 to analyze the cross-sectional area and volume of the dominant follicle and corpus luteum. Data were analyzed in SAS. A treatment by month interaction was observed for BW and CG, whereby IUHT heifers were lighter (3, 7, and 8 mo) and had smaller CG (3, 4, and 8 mo). Additionally, IUHT heifers had shorter HH (114.8 vs. 117.5 ± 0.6 cm; IUHT vs. IUCL), BL (100.6 vs. 102.2 ± 0.5 cm), and WH (108.3 vs. 110.4 ± 0.6 cm) and smaller HC (74.9 vs. 75.8 ± 0.3 cm). The distance between the teats and width of the MG did not differ, but teat lengths were shorter in IUHT heifers (front teats: 25.5 vs. 28.3 ± 0.6 mm; rear teats: 22.1 vs. 24.4 ± 0.6 mm). At 12 mo, MG length was shorter in IUHT than IUCL heifers (78.5 vs. 85.5 ± 1.4 cm). Fewer proliferating (0.38 vs. 0.85 ± 0.10%) and ERα-positive cells (10.1 vs. 12.8 ± 0.7%) were observed in IUHT heifers. In the MG fat pad, IUHT heifers had more adipocytes, particularly on d 13 (47.7 vs. 33.9 ± 3.3 cells). Although systemic P&lt;sub&gt;4&lt;/sub&gt; was similar, E&lt;sub&gt;2&lt;/sub&gt; concentrations were reduced in IUHT heifers on d 0 (3.8 vs. 5.0 ± 0.3 pg/mL). Additionally, IUHT heifers had a smaller follicle diameter and volume (diameter: 13.5 vs. 15.5 ± 0.6 mm; volume: 1,468.0 vs. 2,208.5 ± 262.0 mm&lt;sup&gt;3&lt;/sup&gt;) and a smaller corpus luteum diameter and volume (diameter: 22.2 vs. 26.9 ± 0.7 mm; volume: 6,170.4 vs. 10,506.0 ± 617.7 mm&lt;sup&gt;3&lt;/sup&gt;). Overall, exposure to in utero heat stress had lasting implications, leading to a disruption in the crosstalk between the MG and ovaries during the peripubertal phase. The observed effects during peripuberty may provide insigh","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143951708","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 supplementing high-fiber or high-starch concentrates or a 50:50 mix of both to late-lactation dairy cows fed cut herbage on methane production, milk yield, and ruminal fermentation.","authors":"M M Della Rosa, T J Bosher, M A Khan, E Sandoval, B Dobson-Hill, F N Duranovich, A Jonker","doi":"10.3168/jds.2024-26213","DOIUrl":"https://doi.org/10.3168/jds.2024-26213","url":null,"abstract":"<p><p>High-fiber and high-starch concentrates are used as supplements to meet the energy demand of lactating cows or to fill herbage shortage in pastoral systems. Additionally, concentrates can be a tool to mitigate enteric methane (CH₄) per unit of DMI (CH₄ yield) and per unit of milk production. This study aimed to compare the effects of supplementing herbage-fed late-lactation dairy cows with high-fiber (FIB), high-starch (STA), or a 50:50 mix of both concentrates (MIX) compared with no supplementation (CON) on CH₄ emission parameters and ruminal fermentation. Multiparous cows (Friesian × Jersey, average ± SD; 3.8 ± 0.8 yr old; 519 ± 50 kg BW, 211 ± 10 DIM; n = 32) were blocked by lactation number and then randomly allocated to receive (on a DM basis) the following: 0 kg/d of concentrate (CON), 5 kg/d of STA, 5 kg/d of FIB, or 5 kg/d of MIX (2.5 kg each of STA and FIB). After at least 14 d of diet adaptation, the CH₄ emissions, DMI, and milk production were measured in respiration chambers for 48 h, ruminal fluid was collected after chamber measurements, and short-chain fatty acids (SCFA) were analyzed. Daily milk production was recorded, and milk samples were analyzed for milk composition. The CH₄ production (g/d) tended to be greater in concentrate-fed cows than CON cows. The CH₄ yield was similar across the dietary treatments. The CH₄ per kg of TS (calculated as fat plus protein production) was 22% less and tended to be up to 24% less per kg of fat- and protein-corrected milk (FPCM) in concentrate-fed cows than CON cows mainly due to an increase in FPCM production. After morning and afternoon feeding, the time to reach peak CH₄ emissions was less in concentrate-fed cows than CON cows. The variation in the CH₄ emission rate after morning feeding was greater in concentrate-supplemented cows than CON cows. The ruminal SCFA profile was similar among treatments. Regardless of the dietary treatment, the acetate plus butyrate to propionate plus valerate ratio was positively associated with CH₄ yield, FPCM, and peak CH₄ emission rate and negatively associated with the CH₄ decline rate after peak emissions. High-starch, high-fiber, or mixed (50:50) concentrates trended to reduce the CH₄ per unit of FPCM by up to 24% in lactating cows eating fresh herbage as a basal diet.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143960195","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":"Meta-analysis of the effects of supplemental leucine alone or in combination with other branched-chain amino acids on lactational performance in dairy cows and the associated influencing factors.","authors":"Xiaowen Wang, Mengxu Sun, Zhisheng Hu, Hengrui Zhan, Dengpan Bu, Lianbin Xu","doi":"10.3168/jds.2024-25751","DOIUrl":"https://doi.org/10.3168/jds.2024-25751","url":null,"abstract":"<p><p>Effects of Leu or in combination with Ile and Val (ILV) supplementation on lactational performance in dairy cows as well as the potential interfering factors need to be systematically investigated. PubMed, ScienceDirect, Web of Science and Google Scholar databases were searched for peer-reviewed papers published by August 31, 2024 to explore the factors influencng the effects of branched-chain amino acid (BCAA) supplementation in dairy cows. Weighted mean difference (WMD) with confidence interval (CI) of continuous variables from 17 studies were pooled using a hierarchical 3-level meta-analysis with a random-effect model. Moderator analyses were performed to evaluate the effects of different cow breed, lactational stage, dietary MP supply, basal diet type, supplementation method, and supplementation dosage and duration on the heterogeneity of outcomes. Results showed that Leu supplementation increased the milk protein concentration, and ILV supplementation tended to increase milk protein yield in dairy cows. The positive effect of Leu supplementation on milk protein concentration was more prominent in dairy cows fed a MP-adequate or corn silage based diet. Moreover, the milk protein concentration of cows had a tendency to increase when Leu was supplemented via infusion rather than feeding a rumen-protected Leu. Further analysis showed that total digestible Leu should be supplied at 266 g/d (or 11.2% of MP) or supplementation with a duration of 7 d, and total digestible ILV should be supplied at 620 g/d (or 24.2% of MP), to achieve the optimal performances in dairy cows. These findings indicated the benifical effects of supplemental Leu and ILV on milk protein output in dairy cows.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143955817","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":"Milk residue concentrations of ivermectin following pour-on administration to pregnant Holstein cows during different dry periods.","authors":"Fan Yang, Yang-Guang Jin, Shao-Zu Hu, He-Ying Yang, Xiao-Qing Zhu, Ming-Hui Duan, Ze-En Li, Yan Dai, Yue Liu, Shuai-Peng Li, Fang Yang","doi":"10.3168/jds.2025-26384","DOIUrl":"https://doi.org/10.3168/jds.2025-26384","url":null,"abstract":"<p><p>This study aimed to compare ivermectin residue concentrations in milk following pour-on administration to Holstein cows at different stages of the dry period and to determine the necessary milk withdrawal period. Thirty dry cows were evenly divided into 3 groups based on estimated calving dates and received a single pour-on treatment of ivermectin at 0.5 mg/kg BW either 10, 20, or 30 d before these dates. Milk samples were collected 2 times daily for 7 consecutive days beginning on the second day after calving. The marker residue, 22,23-dihydroavermectin B1a, was measured using ultra-high-performance liquid chromatography tandem-MS/MS analysis, with the method showing strong correlation coefficients between 2.5 and 20 ng/mL. The limits of detection and quantification were 2 ng/mL and 2.5 ng/mL, respectively. The concentration-time data were analyzed using a noncompartmental model, and the milk withdrawal period was calculated with WTM 1.4 software. Results showed that when cows received ivermectin more than 10 d before calving, residue concentrations in milk were undetectable or present only in trace amounts, well below China's maximum residue limit (MRL) for ivermectin (10 ng/mL). In contrast, cows treated within 10 d before calving had a milk elimination half-life of 3.8 d for 22,23-dihydroavermectin B1a, with a peak concentration in milk of 13.75 ± 8.12 ng/mL at 1.70 ± 1.68 d postcalving. Based on China's MRL and the observed results, no milk withdrawal period is required if the interval between pour-on administration and calving exceeds 10 d. However, a 4-d withdrawal period after calving is recommended when the interval is shorter. In contrast, in countries without an established MRL, the presence of any detectable ivermectin residue (even below 10 ng/mL) would be a violation.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143954565","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 effect of including plantain (Plantago lanceolata L.) in perennial ryegrass and white clover pastures on milk production and nitrogen excretion of dairy cows throughout the grazing season.","authors":"C T Minogue, T M Boland, I Etxeberria, N A Walsh, A G Fahey, M Dineen, Z C McKay","doi":"10.3168/jds.2024-25966","DOIUrl":"https://doi.org/10.3168/jds.2024-25966","url":null,"abstract":"<p><p>The objective of this study was to investigate the effect of including plantain (Plantago lanceolata L.; PL) in a perennial ryegrass (Lolium perenne L.; PRG) and white clover (Trifolium repens L.; WC) pasture mixture grazed by dairy cows on DMI, milk production and composition, and N excretion throughout the grazing season. Twenty-six (6 primiparous and 20 multiparous) Holstein-Friesian dairy cows were blocked on parity and assigned to 1 of 2 dietary treatments, balanced for economic breeding index, calving date, BW and BCS at calving, and milk production. Treatments were PRG and WC pasture and PRG, WC, and PL pasture (GCP), supplemented with concentrate feed at milking (daily at 0730 and 1500 h). Cows grazed their allocated pasture from d 4 postpartum until the end of the grazing season (34-wk study). Nitrogen excretion was quantified during 2 N partitioning studies; conducted when cows were in early (61 ± 11 DIM; wk 10) and late (214 ± 11 DIM; wk 32) lactation. Cows offered GCP had a 6% lower daily milk solids yield in early lactation (EL) but a 9% greater daily milk yield in late lactation (LL). Milk fat concentration was significantly lower from cows offered GCP in EL and LL. Treatment did not significantly affect cumulative milk, milk fat, or milk protein yield per cow, however, cows offered GCP had a numerically lower cumulative milk solids yield (433 kg/cow vs. 451 kg/cow). Estimated pasture DMI was greater for cows grazing GCP in the EL (+10%) and LL (+16%) N partitioning studies. Dietary PL content was 33% and 32% of GCP cows' total DMI in the early and LL N partitioning studies, respectively. Nitrogen utilization efficiency was 12% lower for cows grazing GCP in the EL N partitioning study (27.5% vs. 31.2%) but 13% greater in the LL N partitioning study (22.3% vs. 19.7%). Estimated total urine volume was greater in both N partitioning studies for cows grazing GCP, and urinary N excretion (-30%) and concentration (-39%) were only lower in the LL N partitioning study for cows on the GCP treatment.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143955302","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":"Supplementing sialyllactose to colostrum replacer improved intestinal health and blood immunity by affecting the abundance of intestinal bacteria in dairy calves.","authors":"Yanting Huang, Wenli Guo, Yingying Cheng, Xinran Wang, Yiting Zhao, Qvan Zhou, Guobin Hou, Tianyu Chen, Jingtao You, Wenzhuo Dong, Guanglei Liu, Shangru Li, Shuai Liu, Wei Wang, Mengmeng Li, Shengli Li, Zhijun Cao","doi":"10.3168/jds.2024-25899","DOIUrl":"https://doi.org/10.3168/jds.2024-25899","url":null,"abstract":"<p><p>Sialyllactose (SL) and its derivatives possess various nutritional and biological benefits for mammals, whereas its effects on dairy calves have not been well characterized. This study evaluated the effects of SL supplementation to colostrum replacer on growth performance, blood immune parameters, intestinal development and microbial composition of preweaned dairy calves. Fifty-six newborn Holstein calves were randomly allocated to either a control group (CON; n = 28; 17 males, 11 females) receiving colostrum replacer without SL supplementation, or a treatment group (CSL; n = 28; 17 males, 11 females) receiving colostrum replacer with SL supplementation. Subsequently calves were fed milk replacer. Starter was provided from d 3. Data on feed intake, feces scores, and disease treatment were recorded daily from d 1 to d 56. Body weight and body size were measured on d 0 (after birth immediately), 14, 28, 42, and 81. Blood samples were collected on d 1 (>24 h), 7, 28, and 56. Fecal samples were collected on d 7 and 28. To analyze intestinal morphology and gene expression, 6 bull calves in each group were harvested at 7 d of age. The results showed that SL administration increased starter DMI. The body weight, heart girth and withers height of the calves in CSL group tended to be higher than those in CON group. The SL administration affected the inflammatory cytokines in serum by increasing interleukin-6 and haptoglobin protein (HPT) on d 1 and interleukin-1β, tumor necrosis factor-α (TNF-α) and HPT on d 7, then decreasing interleukin-1β and TNF-α on d 28 and interleukin-6, TNF-α, c-reaction protein, serum amyloid A and HPT on d 56. The SL administration resulted in higher diamine oxidase in serum on d 7. The SL supplementation elevated the expression of ZO-1 in jejunum epithelial cells. Supplementing SL affected the intestinal microbiota by increasing the abundances of Erysipelotrichaceae_UCG-003, Bacteroides, Parasutterella, Sutterella, Actinomyces, Megamonas, and Sharpea, and decreasing the abundances of Klebsiella, Fusobacterium, Gastranaerophilales, Colidextribacter, and Desulfovibrio. Lactobacillus prophage enriched in the intestine of CSL group calves on d 28 had a negative correlation with IL-1β, IL-6, TNF-α, serum amyloid A, HPT, diamine oxidase and D-lactic acid in serum. In conclusion, supplementing SL in colostrum replacer may promote the growth and health by increasing starter intake, improving the barrier of intestine, and changing the abundance of intestinal bacteria in calves.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143962564","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":"In vitro evaluation of slow-release urea compounds.","authors":"S W Ma, J A Arce-Cordero, R R Lobo, E Sarmikasoglou, J R Vinyard, M L Johnson, A Bahman, G Dagaew, P Sumadong, M U Siregar, G K Salas-Solis, K A Estes, D Vyas, A P Faciola","doi":"10.3168/jds.2024-25882","DOIUrl":"https://doi.org/10.3168/jds.2024-25882","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The objective of this study was to evaluate the effects of different slow-release urea (SRU) compounds on ruminal fermentation, nutrient degradation, and nitrogen (N) utilization in a dual-flow continuous-culture system (experiment 1), as well as ammonia-N (NH&lt;sub&gt;3&lt;/sub&gt;-N) release rate in a batch culture system (experiment 2). In experiment 1, 8 fermenters were used in a replicated 4 × 4 Latin square design with 4 treatments and 4 experimental periods. The treatments were formulated to contain the same amount of N, differing in the source of nonprotein N, such as control (CON), with noncoated urea at 0.62% DM; partial inclusion of SRU compound 1 (SRU1) at 0.51% DM; partial inclusion of SRU compound 2 (SRU2) at 0.51% DM; and partial inclusion of SRU compound 3 (SRU3) at 0.51% DM. Each period lasted 10 d. The last 3 d of each period were used for sample collection. Samples were collected for pH, lactate, VFA, NH&lt;sub&gt;3&lt;/sub&gt;-N kinetics, nutrient degradability, and N metabolism. In experiment 2, a batch culture incubation was conducted as a complete randomized block design, using 3 Erlenmeyer flasks per treatment in 3 runs. Each treatment contained 1 of the 4 NPN sources used in experiment 1, (CON, SRU1, SRU2, SRU3) or without any NPN (blank, BK), and samples were collected at different time points for NH&lt;sub&gt;3&lt;/sub&gt; analysis. All flasks, except for BK, contained equal amounts of 21.56 mg N, and all flasks were inoculated with 260 mL of a 1:2 mixture of ruminal fluid and nutritive solution. Data of both experiments 1 and 2 were analyzed using the MIXED procedure of SAS. In experiment 1, there were no effects of treatment on pH or NH&lt;sub&gt;3&lt;/sub&gt;-N kinetics. There were no effects of treatments on lactate kinetics; however, there was an interaction between treatment and time. For 24-h VFA pool, there were treatment effects on acetate, propionate, acetate:propionate ratio (A:P), and branched-chain (BC)VFA proportion. Compared with CON, SRU1 had lower A:P ratio and acetate proportion, with greater proportion of propionate, which could represent a favorable fermentation partner compared with CON. Treatment SRU1 had lower BCVFA proportion than the other treatments, which indicates less protein degradation. There were no treatment effects for nutrient degradability and N flow. Based on observations in experiment 1, SRU1 could have the potential of improving ruminal fermentation and N utilization. Moreover, the different SRU compounds had different fermentation patterns according to their VFA profiles. In experiment 2, there were significant effects for treatment and time, and a tendency for treatment by time interaction effect. The N release rate of SRU1 was similar to CON and faster than SRU2 and 3, and the differences in N release rates could be detected as early as at 0.75 h of incubation. Thus, SRU1 may not be as slow degrading when compared with SRU2 and 3. In conclusion, no effects were found on nutrient degradability and N utilization. However","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143956713","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 most effective strategy for verifying the absence of sanitizer contamination in milk depends on the sanitizer type used in fluid milk processing facilities.","authors":"Leonie Kemmerling, Alina Stelick, Nicole Martin, Martin Wiedmann, Aljosa Trmcic","doi":"10.3168/jds.2025-26394","DOIUrl":"https://doi.org/10.3168/jds.2025-26394","url":null,"abstract":"<p><p>Contamination of fluid milk with chemicals used for equipment sanitation is a safety and quality concern that has led to incidents of consumers being exposed to milk contaminated with sanitizer. In this study, we first surveyed dairy processors to determine common practices regarding the use of sanitizers in fluid milk processing facilities and the suitability of different preventive and verification practices as part of comprehensive best practices to prevent unintentional sanitizer contamination. Because the results of the survey showed that sensory evaluation is a common practice (73% of processors), we performed a series of sensory experiments to evaluate these practices. We determined the odor detection thresholds of the 2 most commonly used sanitizers, peroxyacetic acid- (PAA) and sodium hypochlorite-based sanitizers, in skim milk. Additionally, we assessed the impact of sensory training on the olfactory identification of milk with sanitizer contamination. Overall, we determined large variations in the odor detection thresholds for PAA in skim milk: 1.19 ± 47.72 ppm (n = 11) and 13.63 ± 6.92 ppm (n = 18) for panelists with and without previous training in sensory evaluation of milk, respectively. The odor detection thresholds for sodium hypochlorite were 7.96 ± 4.26 ppm (n = 11) and 7.24 ± 6.40 ppm (n = 16) for panelists with and without prior sensory evaluation of fluid milk experience, respectively. The additional sensory experiments performed during this study indicated that an individual's inherent ability may have a larger impact than sensory training on their ability to detect sanitizer in milk. Panelists could not consistently detect 7.2 ppm sodium hypochlorite in skim milk by smell, whereas consistent odor detection was observed for some individuals at 20 ppm sodium hypochlorite. Therefore, the use of acuity screening may improve the chances of sanitizer detection in milk by a human sensory panel. Other methods, such as pH measurement, alizarol tests, and the ferric reducing antioxidant power assay, were not able to distinguish between samples with added and without added sanitizers, making these methods unsuitable for detecting sanitizer contamination in fluid milk. The effect of added sanitizer on the freezing point depression of milk samples did not differ from the effect of the same amount of added water. Commercial peroxide test strips were found to be most appropriate for detecting the presence of PAA sanitizer in skim milk and could detect concentrations as low as 2 ppm PAA. None of the evaluated commercial test strips were found to be sensitive enough to detect 20 ppm sodium hypochlorite in milk. The insight gained from this work can be used by fluid milk processors to develop manufacturing and testing protocols that will minimize the risk of delivering fluid milk contaminated with sanitizer to consumers.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143958154","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}