浙江嘉兴水蜜桃主产区果实农药残留水平及评价

对嘉兴市水蜜桃的农药残留水平进行研究和分析,了解其农药残留水平及检出情况,并运用相关指数对水蜜桃进行质量安全评价。在嘉兴水蜜桃主产区采集试样;采用毛细管气相色谱法测定180份样品中有机磷、有机氯及拟除虫菊酯类农药残留量。结果表明,嘉兴地区水蜜桃的主要污染为农药乐果、敌敌畏、氰戊菊酯、氯氰菊酯、溴氰菊酯、三氟氯氰菊酯和甲氰菊酯。水蜜桃果实中农药品种检出率为30.4%,样品农药检出率为93.3%。经单项污染指数的统计分析,确定嘉兴地区水蜜桃生产上的关键控制农药为敌敌畏和三氟氯氰菊酯。嘉兴水蜜桃主产区水蜜桃品质基本安全。     

进口粮谷中农药残留状况普查与分析

目的根据各进口国粮谷样品农药残留检出情况,确立进口粮谷中重点监测的农药残留品种和评估潜在的农药残留风险。方法采用修改的GB/T 19649-2006和GB/T 20770-2008方法,对粮谷主要进口口岸青岛、深圳和秦皇岛在2010~2014年期间进口的62例大豆、62例大麦和28例大米样品进行了690种农药残留检测,共获得104880个检测数据。结果来自6个进口国的62例大豆样品均未检出农药残留。来自3个进口国的62例大麦样品中,有8例样品检出5种农药,检出率12.9%;其中检出1种农药的样品占4.8%,检出2种农药的样品占6.5%,检出3种农药的样品占1.6%;检出的农药残留水平在10~1000μg/kg范围的占检出总数的85.7%,大于1000μg/kg占检出总数的14.3%。来自6个进口国的28例大米样品中,有5例样品检出5种农药,检出率17.9%;其中检出1种农药的样品占14.3%,检出2种农药的样品占3.6%;检出的农药残留水平低于10μg/kg占检出总数的50.0%,大于10μg/kg占检出总数的50.0%。大麦和大米样品中检出的农药品种为低毒农药的均占80%,检出的农药为中毒农药的均占20%。按照中国最大残留限量(MRL)标准衡量,只有1例大麦样品检出的溴氰菊酯超出标准要求;按照欧盟MRL标准衡量,4例大麦样品检出的杀螟硫磷超出标准要求;按照日本MRL标准衡量,没有样品检出超标农药。结论我国进口粮谷的农药残留检出率低于10%。农药残留水平处于安全水平。但同时也应当加强溴氰菊酯、杀螟硫磷、甲基嘧啶磷、毒死蜱、甲基毒死蜱、丙环唑、嘧菌酯、增效醚的检测,特别是溴氰菊酯和杀螟硫磷农药残留的监控,以保障消费者的食品安全。     

新疆红枣农药残留风险评估与排序

为明确残留农药对新疆红枣质量安全的危害水平及其排序,本文以新疆10县市产出的124份红枣样品为研究对象,并对37种农药残留进行了测定,在此基础上,通过急性、慢性膳食摄入风险分析,探讨了残留农药对红枣质量安全的危害水平;并采用风险矩阵,对残留农药进行了风险排序。结果显示,样品中残留11种农药;残留农药的% ADI(慢性膳食摄入风险)值远小于100%;10种农药的% ARfD值(急性膳食摄入风险)也远低于100%;较其他残留农药,哒螨灵、毒死蜱、苯醚甲环唑、氯氟氰菊酯、氯氰菊酯、甲氰菊酯6种残留农药风险值相对较高,均大于12.05。结论:新疆红枣残留农药的膳食风险较低,哒螨灵、毒死蜱、苯醚甲环唑、氯氟氰菊酯、氯氰菊酯、甲氰菊酯为需重点关注的农药。     

七成“有机”样品检出农残

<正>9月10日,天津市消协发布了2015年蔬菜比较试验报告,报告显示,认证蔬菜样品单项农残检出率高于常规蔬菜样品,近七成"有机"样品被检测出农药残留。检测结果显示,31个蔬菜样品总汞、铅、总砷等3项重金属污染物限量指标,全部符合相关标准要求。乐果、杀螟硫磷、毒死蜱、氯氰菊酯、氯氟氰菊酯等5项农药残留均未检出。2个样品检出腐霉利农药残留,12个蔬     

河北产区桃农药残留风险评估

目的 明确河北产区桃中农药残留水平和风险状况。方法 在河北省采集70份桃样品进行农药残留检测与分析,对检出农药残留行急性和慢性膳食摄入风险评估,并利用风险排序矩阵对农药残留风险大小进行排序。结果 70批次桃样品共检出农药残留33种,农药残留检出率为100%,个别样品存在农药残留超标现象,超标农药为多菌灵和甲氨基阿维菌素苯甲酸盐。桃中检出农药的慢性膳食摄入风险(%ADI)在0.00%～1.06%之间,急性膳食摄入风险(%ARfD )在0.00%～11.34%之间。根据农药残留风险排序结果,高风险农药共有5种,其中毒死蜱和甲氨基阿维菌素苯甲酸盐检出率较高,分别为45.7%和18.6%。结论 河北地区桃样品中农药残留检出率较高,但94.3%的样品中农药残留量符合国家限量标准,桃中农药残留急性和慢性膳食摄入风险均处于较低水平,其中,多菌灵、毒死蜱和甲氨基阿维菌素苯甲酸盐是桃中应重点关注的风险因子。     

黔江区桑叶中重金属污染及农药残留现状分析与评价

目的 对重庆市黔江区桑叶中5种重金属污染和42种农药残留进行测定,为辖区内蚕桑业的发展、桑叶类药食产品的质量安全控制提供参考依据。方法 从黔江区内4个片区共采集196批样品,采用电感耦合等离子体质谱法、气相色谱-质谱法进行重金属及农药残留的测定,用内梅罗污染指数法、单因子污染指数法等方法综合评价重金属污染及农药残留风险。结果 196批次桑叶样品中,共检出重金属196批次,检出率100%,污染类型为复合型重金属污染,其中铬（Cr）检出率最高,为96.94%,铅（Pb）次之,Cd（镉）未检出。选取其中154批桑叶进行农药残留检测,检出农药残留样品55批次,检出率为35.71%;42种农残项目中检出12种,其中毒死蜱、敌敌畏检出频次较高;不同乡镇片区之间及不同月份检出情况存在极显著差异（P<0.01）,金溪片区检出数及检出率最高。结论 部分乡镇农药使用情况较为普遍,重金属含量偏高,过量食用可能会存在一定风险,需引起相关部门注意。     

英德横石水镇贫困村蔬菜中农药残留及重金属污染分析

本文研究分析了英德横石水镇溪北村蔬菜中的农药残留和重金属污染。选取24个蔬菜样品,采用气相色谱-双火焰光度检测器(GC-FPD)测定蔬菜中的甲胺磷、甲拌磷、特丁硫磷、甲基对硫磷、杀螟硫磷、甲基异柳磷、丙溴磷、伏杀硫磷、敌敌畏、乙酰甲胺磷、治螟磷、氧乐果、乐果、毒死蜱、马拉硫磷、对硫磷、水胺硫磷、杀扑磷、三唑磷和亚胺硫磷等20种有机磷农药残留;采用气相色谱-电子捕获检测器(GC-ECD)测定蔬菜中的α-六六六、β-六六六、γ-六六六、δ-六六六、百菌清、三唑酮、甲氰菊酯、哒螨啉、氯氰菊酯、氰戊菊酯、溴氰菊酯和氟虫腈等12种农药残留;采用原子吸收-石墨炉法测定铅含量;原子荧光分光光度法测定砷和汞含量,结果表明蔬菜样品中均未检出上述32种农药及3种重金属。研究结果可为英德横石水镇溪北村蔬菜质量定位提供理论依据。     

韭菜中农药残留状况调查与分析

目的了解韭菜中农药残留状况。方法抽取北京市批发市场和蔬菜生产基地销售的韭菜样品174个,检测其中的甲胺磷、氧乐果等58项农药残留,并依据GB 2763-2019《食品中农药最大残留限量》进行判定。结果市场销售韭菜农药残留的检出率明显高于生产基地, 7～8月份的韭菜农药残留检出率相对较低,检出率排在前5位的农药依次为腐霉利20.6%,多菌灵11.2%,氯氰菊酯8.62%,毒死蜱和嘧霉胺7.47%,其中腐霉利是引起韭菜农药残留超标的主要原因之一,检出2种以上农药的韭菜占检出样本总数的64.3%。结论韭菜中检出的农药种类较多,属于高风险的蔬菜品种之一,韭菜质量安全状况还需进一步加强,需要引起有关部门的重视。     

拟除虫菊酯在培养料和白灵菇中的消解动态

针对食用菌中农药残留污染现状,研究探讨拟除虫菊酯在白灵菇拌料、灭菌、接种培养、出菇管理过程的消解动态及转移规律。结果表明,常压高温灭菌条件下,4种菊酯农药的降解率在33%～39%,其中溴氰菊酯和高效氯氰菊酯的降解率相对较高;在出菇试验中,在菌料中喷施3个浓度水平的菊酯农药,获取农药在菌料中的动态残留及子实体、菌糠的最终残留数据,得到四种菊酯在菌料中的半衰期为14.26 d～24.71 d;在子实体喷施试验中,分析农药在子实体生长过程的动态残留规律,获得其半衰期为3.03 d～4.22 d;在转移试验中,菌糠中四种菊酯的检出率为100%,子实体未有检出。该研究成果对拟除虫菊酯在菌菇生产中的规范化使用提供一定的理论基础和数据支持。     

新疆甜瓜农药残留膳食风险评估

以两年度新疆主产区127个甜瓜样品为研究对象,在完成甜瓜中60项农药残留分析的基础上,通过慢性、急性膳食暴露评估,对其膳食风险水平进行评估,同时采用英国兽药残留委员会兽药残留风险排序矩阵,探讨高风险残留农药种类。结果显示:甜瓜样品中检出苯醚甲环唑、毒死蜱、啶虫脒、多菌灵等10种农药残留,检出率在0.79%～22.05%;残留农药的慢性膳食摄入风险值和不同人群的急性膳食摄入风险值均远低于100%,毒死蜱、苯醚甲环唑和虫螨腈风险得分分别为24.03,18.12,18.05,高于其他种残留农药,样品存在农药残留的现象;但其膳食风险不高,毒死蜱、苯醚甲环唑和虫螨腈为高风险残留农药,需加强关注。     

Dietary restriction improved feed efficiency of inefficient lactating cows

The aim of this study was to reduce voluntary dry matter intake (DMI) to increase feeding efficiency of preclassified inefficient (INE) dairy cows through restricted feeding. We studied the effects of dietary restriction on eating behavior, milk and energy-corrected milk (ECM) production, in vivo digestibility, energy balance, and measures of feed efficiency [residual feed intake (RFI) and ECM/DMI]. Before the experiment, 12 pairs of cows were classified as INE. The 2 dietary treatments consisted of ad libitum feeding versus restricted feeding of the same total mixed ration containing 36.5% roughage. Inefficient cows fed the restricted total mixed ration had a shorter eating time and lower meal and visit frequency, but a similar rate of eating, meal size, and meal duration compared with INE cows fed ad libitum. Compared with the INE cows fed ad libitum, restricted INE cows had 12.8% lower intake, their dry matter and neutral detergent fiber digestibility remained similar, and their ECM yield was 5.3% lower. Feed efficiency, measured as RFI, ECM/DMI, and net energy retained divided by digestible energy intake, was improved in the restricted INE cows as compared with the ad libitum cows. Our results show that moderate DMI restriction has the potential to improve feed efficiency of preclassified INE cows.     

Characterization of the microbial community and its changes in liquid piglet feed formulations

The stability of the microbial populations in liquid piglet feed formulations was studied over a period of 3 months. Total aerobic bacteria, lactic acid bacteria, proteolytic bacteria, amylolytic bacteria, lipolytic bacteria, Bacillus cereus group and yeasts and moulds were monitored using selective media. The results demonstrated a tendency for slight increases in the numbers of total aerobic bacteria (p = 0.002), lactic acid bacteria (p = 0.014), proteolytic bacteria (p = 0.006) and lipolytic bacteria (p = 0.003). The numbers of amylolytic bacteria (p = 0.791) and yeasts and moulds (p = 0.620) were more variable, and Bacillus cereus‐like bacteria were nearly absent. Lactic acid bacteria, especially lactobacilli and leuconostocs, were the predominant population, indicating that a natural fermentation occurred, reducing the pH of the feeds to 4.7. The presence of proteolytic, lipolytic and amylolytic bacteria could theoretically lead to an improvement in the digestibility of the feeds. Copyright © 2004 Society of Chemical Industry     

饲料储藏品质指标研究

粗脂肪含量不同的三种饲料分别储藏在温度10℃、相对湿度80%～85%和温度30℃、相对湿度30%～35%的恒温恒湿箱中120天。在储藏前后测定了饲料中粗脂肪、水分、氨基酸总量、氨含量以及酸值和过氧化值。储藏中除前30天外,以后每隔15天测定分析饲料的酸值和过氧化值。结果表明:饲料经储藏后,粗脂肪含量降低,氨基酸总量也略有降低,但氨含量略有增加,饲料水分随储藏条件的相对湿度变化。随饲料储藏时间的延长,饲料酸值增加,饲料过氧化值增长较快。储藏温度和湿度对饲料储藏品质有影响。     

高速分件供送螺杆全程单函数运动规律及特性分析

根据分件供送工艺要求，用一种新方法推出了变螺距供送螺杆全程单函数运动规律。在计算机上分析了该运动规律的各特性函数及其图象，证明它是一种全程统一、自然连续、惯性冲击小、动力特性好且应用方便的优良运动规律。此外，还探讨了螺杆基本参数的变化规律。为变螺距供送螺杆理论和设计的发展，提供了新的途径。     

Breeding goal traits accounting for feed intake capacity and roughage or concentrate intake separately

Current breeding tools aiming to improve feed efficiency use definitions based on total dry matter intake (DMI); for example, residual feed intake or feed saved. This research aimed to define alternative traits using existing data that differentiate between feed intake capacity and roughage or concentrate intake, and to investigate the phenotypic and genetic relationships among these traits. The data set contained 39,017 weekly milk yield, live weight, and DMI records of 3,164 cows. The 4 defined traits were as follows: (1) Feed intake capacity (FIC), defined as the difference between how much a cow ate and how much she was expected to eat based on diet satiety value and status of the cow (parity and lactation stage); (2) feed saved (FS), defined as the difference between the measured and the predicted DMI, based on the regression of DMI on milk components within experiment; (3) residual roughage intake (RRI), defined as the difference between the measured and the predicted roughage intake, based on the regression of roughage intake on milk components and concentrate intake within experiment; and (4) residual concentrate intake (RCI), defined as the difference between the measured and the predicted concentrate intake, based on the regression of concentrate intake on milk components and roughage intake within experiment. The phenotypic correlations were ?0.72 between FIC and FS, ?0.84 between FS and RRI, and ?0.53 between FS and RCI. Heritability of FIC, FS, RRI, and RCI were estimated to be 0.21, 0.12, 0.15, and 0.03, respectively. The genetic correlations were ?0.81 between FS and FIC, ?0.96 between FS and RRI, and ?0.25 between FS and RCI. Concentrate intake and RCI had low heritability. Genetic correlation between DMI and FIC was 0.98. Although the defined traits had moderate phenotypic correlations, the genetic correlations between DMI, FS, FIC, and RRI were above 0.79 (in absolute terms), suggesting that these traits are genetically similar. Therefore, selecting for FIC is expected to simply increase DMI and RRI, and there seems to be little advantage in separating concentrate and roughage intake in the genetic evaluation, because measured concentrate intake was determined by the feeding system in our data and not by the genetics of the cow.     

微生物与酶制剂在秸秆发酵饲料生产中的应用

利用微生物的自身代谢活动与酶制剂而生产的发酵饲料正逐渐成为解决饲料紧张和环境问题的重要手段。微生物与酶制剂将难以直接消化吸收的农作物秸秆等原料转化成易被牲畜采食消化吸收的、营养价值更高且无毒害的发酵饲料。该文对发酵饲料的定义、在发酵饲料中应用的微生物与酶制剂和生产中存在的问题进行了阐述,并对微生物与酶制剂发酵饲料的进一步发展做了展望。     

Effects of forage presentation and addition of molasses-based liquid feed on dairy calf dietary selection and feed sorting of mixed diets

The objective of this study was to examine the effects of including a molasses-based liquid feed on sorting of a mixed diet of starter and hay, and to compare the nutrient composition of the ration consumed by calves offered hay and starter according to different feed presentations. Holstein bull and heifer calves were exposed for the first 8 wk of life to 1 of 3 feed presentation treatments: (1) starter and hay provided in separate buckets (n = 15), (2) a mixed diet of 80% starter and 20% hay (n = 16), or (3) a mixed diet containing the same ratio of starter and hay, with inclusion of 10% (as-is basis) liquid molasses (n = 14). Calves received 8 L/d of pasteurized waste milk and were weaned over a 10-d period beginning at 42 d of age. Intake was recorded daily and calves were weighed weekly. Fresh and refused feed were sampled on 3 consecutive days during wk 4 and 6 of the preweaning period and wk 8 immediately postweaning. Sorting was assessed through nutrient analysis of the feed samples, with additional sorting indices reflective of sorting for starter and hay components calculated based on weighted averages of individual nutrient intakes as a percent of predicated intakes. Dry matter intake and average daily gain did not differ among treatments. During the preweaning period, addition of molasses to the mixed diet did not affect the extent of feed sorting, with calves provided both mixed diets sorting, on average, in favor of starter and against hay. Postweaning, addition of molasses tended to reduce the extent of feed sorting, although calves on both treatments persisted in sorting for starter and against hay. Across treatments, there was an association between the pre- and postweaning extent of feed sorting, suggesting a degree of individual consistency in sorting behavior. Calves provided starter and hay separately consumed a diet consisting of approximately 18 to 19% hay preweaning and 14% hay postweaning, and generally had greater fiber intake and lower intake of nonfiber carbohydrates compared with calves provided a mixed diet. These results indicate that addition of molasses slightly reduced sorting during the postweaning period only. On average, calves provided both mixed diets sorted their feed in favor of starter and against hay, which mirrored dietary selection exhibited by calves offered hay and starter separately.     

Blood plasma traits associated with genetic merit for feed utilization in Holstein cows

The objective of this study was to evaluate the potential of selection for feed utilization on associated blood plasma metabolite and hormone traits. Dry matter intake (DMI) was recorded in 970 Holsteins from 11 commercial farms in Pennsylvania and used to derive dry matter efficiency (DME; fat-corrected milk yield/DMI), crude protein efficiency (CPE; protein yield/crude protein intake), and residual feed intake (RFI, defined as actual feed intake minus expected feed intake for maintenance and milk production, based on calculation of DMI adjusted for yield, body weight, and body condition score). Estimated breeding values for the 4 feed utilization traits (DMI, DME, CPE, and RFI), yield traits, body traits, and days open were standardized according to their respective genetic standard deviations. Up to 631 blood samples from 393 cows from 0 to 60 d in milk (DIM) were evaluated for blood plasma concentrations of glucose, nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHB), creatinine, urea, growth hormone (GH), 3,5,3′-triiodothyronine (T3), and other parameters. Blood plasma traits were regressed on DIM, lactation number, herd, and standardized genetic merit. Cows with higher genetic merit for yield had significantly higher concentrations of GH, NEFA (milk and protein yield), and BHB (fat yield) from 31 to 60 DIM, but lower concentrations of glucose from 0 to 30 DIM, and T3 (milk yield, 0–60 DIM). The high GH–low glucose–low T3 concentration pattern was further accentuated for cows with genetic merit for enhanced feed efficiency (higher DME and lower RFI). Cows with a genetic tendency to be thin (low body condition score) also had elevated GH concentrations, but lower blood glucose, creatinine, and T3 concentrations. Those characteristics associated with enhanced feed efficiency (higher GH and lower glucose and T3 concentrations) were unfavorably associated with fertility, as indicated by elevated days open. Elevated NEFA and BHB concentrations were also associated with extended days open. Consideration of metabolic profiles when evaluating feed efficiency might be a method of maintaining high levels of health and reproductive fitness when selecting for feed efficiency.     

不同诱食剂对异育银鲫、奥尼罗非鱼作用效果的研究

以平均体重为84、6g的异育银鲫及27g奥尼罗非鱼鱼种为试验对象,进行了3个试验,考察DMPT、鱼溶肽蛋白、甜菜碱、甘氨酸、L-丙氨酸等的诱食效果。结果表明:在饲料中添加0.05%DMPT、0.1%DMPT、0.1%鱼溶肽蛋白、0.3%甜菜碱、1%甘氨酸、0.5%L-丙氨酸以及2%五味子汁对异育银鲫、奥尼罗非鱼均具有极显著的诱食效果(P<0.01)。     

Effect of feed delivery method on the behavior and growth of dairy heifers

The objective of this study was to determine the effects of feed delivery method on growth, feeding competition, feeding, and sorting behavior of dairy heifers. Thirty-two Holstein heifers (146.2 ± 21.9 d of age) were divided into 8 groups of 4 and exposed to 1 of 2 feed delivery treatments for 13 wk. The treatment rations contained 65% grass/alfalfa haylage and 35% textured concentrate (on a dry matter basis) fed as a 1) total mixed ration (TMR) or 2) top-dressed ration (TDR). Group dry matter intakes were recorded daily throughout the experiment. Feeding behavior, recorded using time-lapse video, and sorting behavior were measured for 7 d during each of wk 1, 5, 9, and 13. Sorting activity was determined through particle size analysis of the fresh feed and orts. The particle size separator separated feed into 4 fractions (long, medium, short, and fine). Sorting of each fraction was calculated as actual intake expressed as a percentage of predicted intake. Heifers were fecal scored for consistency of stool twice weekly using a scale from 1 (liquid) to 4 (solid); heifers were weighed every 2 wk. Neither dry matter intake (7.3 kg/d) nor average daily gain (1.3 kg/d) differed between treatments. Heifers fed the TDR tended to consume less neutral detergent fiber than heifers fed the TMR (4.77 vs. 4.91 kg/d). Heifers fed the TDR sorted against long particles (98.9 vs. 96.0%) and consumed short particles (100.3 vs. 101.1%) to a greater extent than did heifers fed the TMR. Daily feeding time did not differ between treatments (201.0 min/d), but heifers on the TDR did spend more time at the bunk in the 2 h following feed delivery (50.1 vs. 32.0 min/d). Heifers fed the TDR were displaced from the feed bunk more frequently than heifers fed the TMR (17.6 vs. 8.6 times/d), particularly during the 2-h period following feed delivery. Fecal scores were lower for heifers on the TDR (2.7 vs. 3.4). These results suggest that feeding a TMR to replacement dairy heifers may promote a more even diurnal feeding pattern, minimize feed sorting and feed bunk competition, and promote more solid fecal consistency.