Short communication: Determination of the milk pharmacokinetics and depletion of milk residues of flunixin following transdermal administration to lactating Holstein cows

Flunixin is a nonsteroidal anti-inflammatory drug and the most commonly prescribed analgesic in cattle in the United States. Recently, the US Food and Drug Administration (FDA) approved a transdermal formulation of flunixin for control of pyrexia associated with bovine respiratory disease and the control of pain associated with foot rot. The transdermal formulation is not currently approved for use in lactating dairy cattle in the United States, but extra-label use in dairy cattle is permissible under US regulations. The objectives of this study were to determine the pharmacokinetics in milk of dairy cows treated with transdermal flunixin and determine an appropriate withdrawal time for milk. Ten lactating Holstein cows were enrolled into the study in mid lactation. Following treatment, cows were milked 3 times per day through 144 h. Milk samples were collected for drug analysis using ultra-high-pressure liquid chromatography coupled with a triple quadrupole mass spectrometer. The geometric mean maximum concentration for flunixin in milk was 0.010 μg/mL and was 0.061 μg/mL for the active metabolite, 5-hydroxyflunixin. The geometric mean terminal half-life was 20.71 h for flunixin and 22.62 h for 5-hydroxyflunixin. Calculations to approximate a withdrawal time in milk following transdermal flunixin administration were accomplished using a statistical tolerance limit procedure. This analysis indicated that it would be prudent to observe a withdrawal period of 96 h following the last treatment. This is more than twice as long as the labeled withdrawal period of 36 h following use of the injectable formulation. The withdrawal period suggested by this work should be applied carefully, as this study was not conducted under the full quality control practices required by the US FDA for a full drug approval study. Caution should be taken when applying this withdrawal time to diseased animals, animals that are milked with different milking frequencies, and those in different stages of production as these have all been shown to affect drug depletion from milk.     

Cadmium and lead in animal tissue (muscle,liver and kidney), cow milk and dairy products in Korea

A survey of Cd and Pb in animal tissue, milk and dairy products was conducted. Muscle, liver and kidney of domestically produced cows, pigs, chickens and ducks were collected from eight regions in Korea. Raw cow milk was collected from 9 regions, and imported dairy products (butter, cheese, cream and powdered milk) were collected from 15 countries. Cd and Pb were analysed by inductively coupled plasma mass spectrometry (ICP-MS) after microwave digestion. Concentrations of Cd and Pb did not exceed the Korean legal maximum levels in any of the samples. Correlation coefficients were estimated between concentration of Cd or Pb and animal age and between muscle, liver and kidney. In cows, there were good correlations between age and Cd in kidney (r = 0.748) and between Cd in liver and in kidney (r = 0.878). Continuous monitoring will be an important role to safeguard consumers in the event of a food contamination incident.     

Nutritional and sensory characteristics of Minas fresh cheese made with goat milk,cow milk,or a mixture of both

This study aimed to assess and compare the nutritional, technological, and sensory characteristics of Minas fresh cheese made with goat milk, cow milk, or a mixture of the two stored in cold conditions for 21 d. The yield and centesimal composition of the cheeses were not affected by the type of milk used in their preparation. Reductions were observed in the moisture content, pH, proteolysis index, and instrumental hardness; moreover, increases were observed in the syneresis, acidity index, and depth of proteolysis index in all cheeses. The percentages of caprylic, capric, oleic, and linoleic fatty acids were higher in goat milk cheese and cheese made with a mixture of goat and cow milk compared with cow milk cheese, and a sensory evaluation revealed differences in color, flavor, and aroma between the cheeses. The preparation of Minas fresh cheese with a mixture of goat and cow milk can be a viable alternative for dairy products in the market that can be characterized as high-quality products that meet consumer demands.     

超高效液相色谱-串联质谱法测定乳及乳制品中苯菌酮的残留量

目的 建立了一种超高效液相色谱-串联质谱法（ultra performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS）对乳及乳制品中苯菌酮的残留量进行定量的检测方法。方法 样品经1%甲酸乙腈提取,经Prime HLB固相萃取小柱净化,以ACQUITY UPLC BEH Phenyl 色谱柱（2.1 mm×100 mm, 1.7 μm）分离,使用乙腈-0.1%甲酸水作为流动相进行梯度洗脱,扫描方式在电喷雾离子源正离子模式下采用多反应监测（multiple reaction monitoring, MRM）模式,采用基质匹配标准曲线校准,外标法定量。结果 苯菌酮在1.0-200.0 μg/L范围内线性关系良好,相关系数（r）均不小于0.996。方法检出限及方法定量限分别为1.5 μg/kg与5.0 μg/kg。在3个添加水平的加标回收实验下,苯菌酮的平均回收率为84.1%~107.5%,相对标准偏差为1.0%~7.2%（n=6）。结论 本方法前处理操作简便,结果准确,灵敏度高,适用于乳及乳制品中苯菌酮残留量的测定。     

Short communication: antibiotic residues in milk following the use of intravaginal sponges for estrus synchronization in dairy ewes

The addition of antibiotics to intravaginal sponges used to synchronize ewe estrus is currently a recommended practice for the prevention of posttreatment vaginal infections. Application of this antibiotic treatment is usually done without withdrawal periods for milk, but official pharmaceutical instructions do not consider the extra-label use of antibiotics, which could result in the presence of antibiotic residues in milk. To understand the effects of the use of antibiotics on the performance of these hormonal treatments, milk collected from a group of Manchega ewes estrus synchronized by intravaginally inserted progestagen sponges jointly impregnated with antibiotics (benzyl penicillin procaine: 1,000,000 IU/25 sponges plus DH-streptomycin: 1 g/25 sponges) was evaluated for antibiotic residue persistence with 5 types of antibiotic screening tests (BRT, Copan CMT, Delvotest MSC, Eclipse 100, and New SNAP Beta-Lactams). Time to antibiotic residue depletion was established by a logistic regression model, and a significant response to milking order was observed in all methods. Positive or doubtful tests were observed after the insertion of intravaginal sponges for all assay screening tests at the time of the first milking and sometimes afterwards.     

Concentration of furfuryl alcohol in fluid milk,dried dairy ingredients,and cultured dairy products

Maillard reactions occur in dairy products during heat treatment. Furfuryl alcohol (FA) may be found in dairy products as a result of Maillard reactions. The recent posting in California Proposition 65 indicates that FA may be carcinogenic, and for this reason it is crucial to accurately measure FA concentrations in dairy products. The objective of this study was to identify an extraction and quantitation method for FA from dairy products and to determine FA concentrations in milk, dairy powders, and cultured dairy products. Solvent-assisted flavor extraction, solid-phase microextraction, stir bar sorptive extraction with gas chromatography-mass spectrometry and triple quadrupole mass spectrometry were compared for recovery of FA. Internal standards for the quantitation of FA (2-methyl-3-heptanone, furfuryl-d₅ alcohol, 2,5-dimethylphenol, 5-methyl-2-furfuryl alcohol, and 5-methyl furfural) were also compared. Subsequently, fluid milk [high temperature, short time (HTST) and ultrapasteurized], whey protein isolates (3 mo–4 yr), whey protein concentrates (3 mo–4 yr), whole milk powders (1 yr), high and low heat skim milk powders (SMP; 0–8 yr), milk protein isolates (3 mo–3 yr), milk protein concentrates (3 mo–3 yr), Cheddar cheese (mild, medium, sharp, and extra sharp), mozzarella cheese (whole and part skim), cottage cheese (nonfat, low fat, and full fat), sour cream (nonfat, low fat, and full fat), traditional yogurt (nonfat, low fat, and full fat), and Greek-style yogurt (nonfat; n = 139 products total) were evaluated. Furfuryl alcohol was extracted from products by headspace solid-phase microextraction followed by gas chromatography-triple quadrupole mass spectrometry using a ZB-5ms column (30 m × 0.25 mm × 0.25 µm; Phenomenex Inc., Torrance, CA). Furfuryl-d₅ alcohol was used as an internal standard. Each food was extracted in triplicate. Ultrapasteurized milks had higher levels of FA than HTST milks (122.3 vs. 7.350 µg/kg). Furfuryl alcohol concentrations ranged from 0.634 to 26.55 µg/kg in whey protein isolates, 2.251 to 56.19 µg/kg in whey protein concentrates, 11.99 to 121.9 µg/kg in milk protein isolates, and 8.312 to 49.71 µg/kg in milk protein concentrates, and concentrations increased with powder storage. High heat SMP had higher concentrations of FA than low heat SMP (11.8 vs. 1.36 µg/kg) and concentrations increased with storage time. Concentrations of FA in Cheddar and mozzarella cheese ranged from 2.361 to 110.5 µg/kg and were higher than FA concentrations in cottage cheese or sour cream (0.049–1.017 µg/kg). These results suggest that FA is present at higher levels in dairy products that have been subjected to higher temperatures or have been stored longer. Sour cream and cottage cheese had lower levels of FA. Compared with other studies on food products with reported levels of FA, such as coffee (200–400 µg/g), dairy products have very low levels of FA.     

Fenthion residues in milk and milk products following treatment of dairy cows for warble-fly

Persistence of the organophosphorus pesticide, fenthion, in the milk of ten dairy cows was determined following treatment of the animals for warble fly (a) while at grass, and (b) while housed and fed on silage. The mean concentration of fenthion in the milk of the housed animals was at a higher level for longer after treatment. Following both treatments, the mean fenthion concentration in milk dropped below 0.05 mg kg^?1 within 24 h of treatment. No correlation was found between milk yield of cows and total fenthion excreted in milk. The fenthion levels in milk and milk products were determined during a compulsory warble-fly eradication scheme. Low fenthion levels detected in milk after processing were due to the dilution effect of bulking milk. Although the tendency for fenthion to accumulate in the fat fraction in milk resulted in measurable levels of the pesticide in butter and cheese, these levels were below 0.05 mg kg^?1.     

Crufomate residues in milk and milk products following treatment of dairy cows for warble-fly

A group of ten dairy cows were treated for warble-fly with the organophosphorus pesticide, crufomate. The persistence of crufomate in the milk of the cows after treatment was determined by gas-liquid chromatography with a phosphorus-specific thermionic detector. The mean crufomate concentration in milk dropped below the Codex maximum limit of 0.05 mg kg^?1 within 24 h of treatment. Crufomate was found to accumulate in the fat fraction of milk, giving rise to a higher concentration of crufomate in milk products, relative to the concentration in whole milk.     

Effect of dietary phosphorus on performance of lactating dairy cows: milk production and cow health

The objective of this study was to measure cow response to feeding of two dietary concentrations of P, one of which was close to recent National Research Council requirements, and the other of which was well in excess of the requirement. Diets containing 0.37 or 0.57% P (dry basis) were fed to Holstein cows for the first 165 d of lactation, and occasionally longer until cows were confirmed pregnant approximately 60 d after insemination. At calving, cows were randomly assigned to experimental diets. The number of cows completing a minimum of 165 d of lactation was 123 for the 0.37 and 124 for the 0.57% P groups. Cows were housed in a stanchion barn and fed one of two transition diets, each formulated to contain one of the P treatments for the first 3 wk of lactation, and then cows were moved to a free-stall barn where the experimental diets were group fed. Milk production, milk fat, and milk protein averaged 35.1 kg/d, 3.92%, and 2.90% for the 0.37% P diet, and 34.9 kg/d, 3.98%, and 2.91% for the 0.57% P diet. None of these measures were different between treatments. Blood serum P concentrations on d 50 and 100 of lactation averaged 6.1 and 6.2 mg/dL for the 0.37% P diet, and 6.8 and 6.9 mg/dL for the 0.57% P diet. No treatment differences were detected in milk production, cow health, or body condition score.     

Enantiomeric fraction of selected chiral polychlorinated biphenyls in cow, goat, and ewe milk and dairy products by heart-cut multidimensional gas chromatography: first results

The concentration of the most relevant polychlorinated biphenyl (PCB) congeners has been determined in milk and dairy products (i.e., cheese and yogurt, from cow, goat, and ewe). In addition, the enantiomeric composition of 11 atropisomeric PCB has been determined for the first time in this type of product, using heart-cut multidimensional gas chromatography and 2 enantioselective columns for the unambiguous determination of both enantiomers. Results showed a deviation from the racemic composition for PCB 135, 136, 176, 171, and 183 in the samples analyzed. Whereas PCB 135, 136, and 176 showed an enrichment of the first eluted enantiomer, congeners 171 and 183 showed an enrichment of the first or second eluted enantiomer depending on the dairy product and species. The remaining congeners analyzed (PCB 84, 91, 95, 132, 149, and 174) did not present a clear enrichment of any of the enantiomers. Therefore, differences in the enantiomeric composition of some of the target atropisomeric PCB have been found among the 3 species and among the milk samples and the related dairy products analyzed. Enantioselective species-dependent processes, as well as enantioselective processes carried on by microorganisms during the fermentation and ripening in the latter could be possible explanations for the differences observed. However, changes in the enantiomeric composition are still not well understood, and further investigation in this direction is recommended.     

Variations in carotenoids, vitamins A and E, and color in cow's plasma and milk following a shift from hay diet to diets containing increasing levels of carotenoids and vitamin E

This experiment was conducted to determine the variations in carotenoid, vitamins A and E concentrations, and color in the plasma and milk of dairy cows following a shift from a hay diet to diets containing increasing levels of carotenoids and vitamin E. This study was performed on 32 multiparous Montbéliarde dairy cows in midlactation. After a 6-wk preexperimental period on a diet based on hay and concentrates, the cows were allocated to 4 homogeneous groups, and thereafter fed for 6 wk on isoenergetic experimental diets where the hay was replaced by an experimental feed rich in carotenoids and vitamin E, consisting in 75% grass silage and 25% alfalfa protein concentrate (PX Agro Super Desialis, Châlons en Champagne, France). The hay-to-experimental feed ratios were 100/0 in group 1, 67/33 in group 2, 33/67 in group 3, and 0/100 in group 4, providing 1.6, 3.6, 5.4, and 7.4 g/d of total carotenoids, respectively. Variations in carotenoid, vitamins A and E concentrations as well as variations in color index (CI) were monitored from d −7 through to d 42 on the experimental diets. Zeaxanthin, lutein, 13-cis-β-carotene, and all-trans-β-carotene accounted for an average 3, 10, 9, and 78%, respectively, of total carotenoids in plasma and 0, 17, 12, and 71%, respectively, of total carotenoids in milk. The switch from preexperimental to experimental diets only slightly affected zeaxanthin, lutein, and vitamin A concentrations in plasma and milk. A rapid increase in vitamin E and β-carotene (BC) was observed during the first week in both plasma and milk. For vitamin E, the time to reach a plateau was from 8 d (group 2) to 28 d (group 4) in plasma, and 5 d (groups 2-4) in milk. Plasma concentrations of BC had stabilized after 28 d in group 2 but were not stabilized after 42 d in groups 3 and 4, whereas milk concentrations of BC plateaued from d 21 in group 2 and d 28 in groups 3 and 4. At the end of the experimental period, BC and vitamin E concentrations in plasma and vitamin E concentrations in milk fat were linearly related to the proportion of experimental feed in the diet. In contrast, BC concentrations in milk fat did not differ between groups 2, 3, and 4, reflecting saturation at high levels of carotenoid intake (i.e., when plasma BC exceeded 5 μg/mL). These results suggested that under high-carotenoid diets, milk secretion of BC is not limited by the amount of plasma BC arriving to the mammary gland but by mechanisms involved in the BC transfer from plasma to milk. These mechanisms will need to be investigated. The BC concentrations were responsible for more than 80% of CI variations in plasma and 56% of CI variations in milk, where there was wide variability among individuals. Plasma CI appeared to be a more promising tool than milk CI as an indicator of the carotene content of the diets ingested by dairy cows.     

Aflatoxins in dairy cow feed,raw milk and milk products from Turkey

This study aims to detect aflatoxins (AFs) in dairy cow feed, milk and milk products using a high-performance liquid chromatography coupled with fluorescence detection (HPLC-FLD) method. All the validation parameters met the method performance criteria of the European Union. The samples comprised 76 dairy cow feeds and 205 milk and milk products (including yoghurt and yoghurt-based beverage, ayran). AFs were present in 26.3% of the feed samples. Two feed samples exceeded the maximum limit (ML) of 5 µg kg^?1 for AFB₁ as established by the EU. Nineteen milk samples (21.1%) contained aflatoxin M₁ (AFM₁) of which three exceeded the EU ML of 0.05 µg l^?1. In addition, only two yoghurt samples and one ayran sample contained AFM₁, but the levels were lower than the EU ML.     

2018—2019年浙江省养殖水产品中6种喹诺酮类药物残留分析及风险评估

目的 评估2018—2019年浙江省养殖水产品中6种喹诺酮类药物残留分析及风险.方法 2018—2019年随机抽检浙江省11个地市658家养殖场的养殖水产品,采用液相色谱-串联质谱法对水产品中恩诺沙星、环丙沙星、氧氟沙星、诺氟沙星、培氟沙星、洛美沙星6种喹诺酮类药物残留进行分析,同位素内标法定量计算得到喹诺酮类药物残留...     

Dioxins and furans in cow milk and dairy products: A review of the scientific literature

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are a group of persistent organic pollutants with well-known toxic effects and potential carcinogenicity. Human exposure to PCDD/Fs is mainly through food, including dairy products. The scientific information on the concentrations of PCDD/Fs in milk and dairy products is here reviewed. It also includes the intake of PCDD/Fs through the consumption of these products. PCDD/Fs concentrations in milk and dairy products are currently decreasing. A similar trend is also noted for their contributions to the total dietary intake of PCDD/Fs. No significant health risks due to exposure to PCDD/Fs through the consumption of dairy products are expected.     

高效液相色谱法测定乳与乳制品中双氰胺的残留

建立了乳与乳制品中双氰胺残留的高效液相色谱测定方法.采用水-乙腈提取样品、氨基色谱柱分离、紫外检测器检测、外标法定量测定双氰胺残留.该方法的检出限为牛奶0.01mg/kg,乳粉为0.05 mg/kg(均为质量分数),线性范围为0.25.0 mg/L,并确定了回归方程,相关系-R2=0.9998,样品加标回收率在90％~8％,相对标准偏差为1.2％~2.3％.该法具有样品处理简单方便,灵敏度高,分析时间短等优点,可以满足乳与乳制品中双氰胺残留的测定.     

Educational interventions to address misconceptions about antibiotic residues in milk can alter consumer perceptions and may affect purchasing habits

The industrialization of the agri-food industry and resultant decrease in the number of people employed on farms has contributed to a knowledge gap among consumers about food production processes. A commonly reported concern of dairy consumers is the use of antibiotics in dairy animals, even though these drugs are an important tool for promoting animal health and welfare and food safety. The extent to which consumers are aware of antibiotic residue avoidance practices in dairy production is unknown, and it is unclear whether acquisition of such knowledge could affect purchasing behavior and perceptions of dairy farming. The objectives of this study were to assess consumers' perceptions about the quality and production of dairy products in the United States and determine whether educational materials on processes that limit the occurrence of antibiotic residues in milk can change consumers' perceptions of dairy products and purchasing behaviors. We surveyed 804 consumers and assigned them to 1 of 3 interventions: (1) a control arm (reading the content of the Dairy page of the USDA's myplate.gov website); (2) an educational brochure on the processes that prevent antibiotic residues in milk; and (3) a video on the same processes. We found that a majority (86.1%) of participants believe that the quality of dairy products in the United States is high, although many had concerns about the treatment of dairy animals and chemicals (pesticides, antibiotics, hormones) in dairy products. Compared with the control intervention, the brochure was associated with a significant decrease in the level of concern consumers had about chemicals in their milk [−0.20 points on a Likert scale, 95% confidence interval (CI), −0.32 to −0.08] and a significantly increased comfort in purchasing conventional dairy products (odds ratio 2.43, 95% CI, 1.62 to 3.66). The video was associated with even stronger effects: a 0.29-unit decrease in the level of concern about chemicals in milk (95% CI, −0.42 to −0.016) and 2.94 times greater odds of purchasing conventional dairy products (95%, CI 1.92 to 4.49). Although consumer food decision making is complex and driven by multiple factors, it appears that education about the processes that promote food safety can reassure consumers about their concerns and potentially affect purchasing habits.     

南湾街道水产品兽药残留监测分析

目的 对南湾街道辖区内水产品兽药残留进行监测分析。方法 针对辖区食品安全形势的特点, 以南湾街道辖区14个社区的农贸市场、超市商场为基础, 采集水产品共885批次。通过快速检测卡运用胶体金免疫层析法进行定性检测, 检测项目为孔雀石绿、氯霉素、呋喃西林代谢物、呋喃唑酮代谢物等, 并对检测结果进行数据分析和评价。结果 885批次水产品, 经检测共有29批次不合格, 不合格率为3.28%, 孔雀石绿、氯霉素、呋喃唑酮代谢物均有检出。结论 辖区内水产品存在一定程度的兽药残留问题, 黄骨鱼、鲫鱼为孔雀石绿检出的高危品, 海水贝类抗生素超标问题比较突出, 氯霉素残留问题仍存在。     

Sensorial and fatty acid profile of ice cream manufactured with milk of crossbred cows fed palm oil and coconut fat

This work was carried out to study the nutritional quality of milk of cows fed palm oil (PAL) or coconut fat (COC), and the use of that milk as raw material for ice cream production. Three treatments were tested with 23 healthy cows: control (CON), PAL, and COC. The milk was collected at d 21 and 36 of the experimental diet. Proximate composition (moisture, ash, fat, protein, and carbohydrates) and fatty acid composition were evaluated on milk and ice cream, and sensorial analysis, color (lightness, green/red, and blue/yellow), overrun, and texture were evaluated on the ice cream. Fatty acids present in milk and ice cream were determined by gas chromatography. Sensory analysis results showed that the ice cream acceptability index was above 70%. No difference was observed for proximate composition in milk and ice cream. Chromatographic analysis showed an increase in saturated fatty acid concentration in CON and lower levels in PAL; polyunsaturated fatty acid concentration was higher in PAL and lower in CON, in milk and ice cream; monounsaturated fatty acid concentration in milk was higher in PAL and lower in CON but no difference was found in ice cream. Comparing n-3 content in milk and ice cream, we observed that PAL had higher levels than CON and COC. The results indicate that it is feasible to add sources of fat to the animal feed for fatty acid composition modulation of milk and ice cream.     

乳和乳制品中抗生素残留的危害及检测方法

综述了乳与乳制品中抗生素残留现状和危害，比较了抗生素检测Delvotest法与其他几种方法。认为Delvotest法优于其他几种方法，建议有关部门尽快引进该技术，以加强我国乳和乳制品中的抗生素监测，解决目前乳业中面临的难题。     

物理技术降解农产品农药残留的研究进展

农药的使用对农业的发展发挥着重大作用,不仅可以使农产品保收、增产,还可以提升产品质量.但使用农药的同时也造成严重的农药污染以及食品安全问题.本文对可降低农产品中农药残留量的物理技术或方法进行了综述,包括光照、超声波、电离辐射、低温等离子体、超高压、洗涤、加热等,以期为相关技术的应用及提升、相关设备和产品的研发生产、农产品生产与消费安全的集成创新,提供理论依据,提高农产品食用安全性.