三嗪类除草剂及其代谢产物的检测方法研究进展

三嗪类除草剂会通过干扰内分泌系统的正常功能影响人类健康,很多国家已将部分此类化合物列入内分泌干扰剂化合物名单。作者从样品提取和仪器检测技术的发展趋势方面综述了环境和食品样品中三嗪类除草剂及其代谢产物的检测方法。在样品提取方面,液液萃取、固相萃取和固相微萃取技术简便且具有较高回收率,广泛应用于三嗪类除草剂的提取。另外,由于分子印迹、凝胶渗透色谱和加速溶剂萃取技术可以提高方法选择性和降低样品基质干扰,因而也越来越多地应用于三嗪类除草剂的提取工作;在检测技术方面,气相色谱和液相色谱法应用最为广泛。此外,由于色谱质谱联用技术可以大大降低方法检测限并能提高阳性样品的定性准确度,符合高通量和痕量检测的发展趋势,因此气相色谱/液相色谱串联质谱技术也广泛应用于三嗪类除草剂残留的定量和定性检测。     

Effects of different supplemental soya bean oil levels on the performance of prepubertal Saanen goats: Oestrogen and progesterone release

The aim of this study was to investigate the effects of different levels of soya bean oil in the total diet on the growth rate, metabolic changes, and oestrogen and progesterone release in Saanen goats. After dietary adaptation, 21 prepubertal goats (weight of 29.12 ± 0.91 kg, 230 days old) were randomly distributed among three diets of D2: inclusion of 2% soya bean oil in the total diet; D3: basal diet – inclusion of 3% soya bean oil in the total diet; and D4: inclusion of 4% soya bean oil in the total diet. The basal diet (D3) was formulated to promote a daily gain of 0.140 kg. The goats were weighed, and their blood samples were collected weekly. Glucose, cholesterol, triglycerides, total protein, urea, non‐esterified fatty acids, beta‐hydroxybutyrate, oestrogen and progesterone in the plasma were measured. Prepubertal goats that were fed D4 exhibited a significantly lower dry matter intake, urea and cholesterol levels compared with the goats that were fed D2 and D3. Indeed, goats that were fed D4 displayed a significantly lower final weight than goats that were fed D2 and D3. In contrast, the inclusion of soya bean oil in the diet increased the progesterone and oestrogen concentrations, and goats that were fed D4 released a significantly higher concentration of progesterone than those that were fed D2 and D3. Furthermore, the percentage of goats with a progesterone level greater than 1 ng/ml (functional Corpus luteum) was significantly higher among the goats that were fed D3 and D4 than among those that were fed D2. In this study, although the inclusion of 4% soya bean oil in the diet decreased dry matter intake and growth rate, it increased progesterone concentration and the percentage of goats with a functional Corpus luteum, suggesting that the inclusion of soya bean oil accelerated puberty in prepubertal goats.     

Effects of outdoor winter housing and feeding level on performance and blood metabolites of suckler cows fed whole-crop barley silage

The experiment studied the effects of long-term cold climatic housing conditions at a latitude of 62°N on pregnant Hereford cows and their progeny. Thirty-five cows in their third parity were overwintered in outdoor facilities with either a rain-shelter or a three-wall shelter, or in an uninsulated barn. Whole-crop barley silage was offered to the cows either ad libitum or restricted supplemented with oats. The dry matter intake on the restricted diet was 75% of that on the ad libitum diet. The cow live weight (LW) averaged 670 kg at the onset of the experiment. During winter the cows outdoors on the restricted diet maintained their LW while those on the ad libitum diet gained LW (P < 0.05, − 3 vs. 41 kg). On pasture, the LW gain (LWG) was 61 and 32 kg (P < 0.05) for the cows overwintered outdoors on the restricted and on the ad libitum diets, respectively. The initial body condition score (BCS, Scale: 0–5) of the cows averaged 2.90. During winter the cows outdoors on the restricted diet decreased and those on the ad libitum diet increased the BCS (P < 0.01, − 0.14 vs. 0.21). On pasture, the cows overwintered outdoors on the restricted diet increased the BCS more than those overwintered on the ad libitum diet (P < 0.05, 0.31 vs. 0.08). No signs of extraordinary stress, massive consumption of energy stores, frequent muscle injuries or severe inflammations occurred in any of the groups according to blood analyses of cows, e.g. cortisol, long-chain fatty acids, aspartate aminotransferase, creatine kinase and white blood cell count. The calving period was from 11 March to 21 April. Only one indoor calving was classified as difficult due to faulty disposition leading to the loss of the calf. All outdoor calvings were easy. The LWG of the indoor calves of cows on the ad libitum diet was poorer (P < 0.05) pre the grazing period than that of the outdoor calves of cows on the ad libitum diet. On pasture and during the entire experiment the LWG was similar for all calves, averaging 1335 and 1251 g/d, respectively. The breeding season was 82 days. Thirty cows out of 33 were observed to be pregnant after the mating period. All the facilities offered adequate shelter for the mature, pregnant suckler cows. The restricted offering of whole-crop barley silage provided, on average, 101 MJ metabolizable energy/d and gave enough energy for the cows.     

Serum IgG,blood profiles,growth and survival in goat kids supplemented with artificial colostrum on the first day of life

The objective of this study was to compare serum IgG concentrations, blood metabolites indicative of nutritional status, weight gain and mortality rate in goat kids fed a commercial colostral supplement containing immunoglobulins against several pathogen microorganisms, prior to the ingestion of the mother colostrum, and goat kids ingesting natural colostrum only. There was no difference in serum IgG concentrations between 27 kids fed a colostrum supplement (20 g, derived from cow lacteal secretions) prior to the kids’ first meal (658 ± 703 mg dl⁻¹) and 21 kids ingesting maternal colostrum freely (1011 ± 1140 mg dl⁻¹) at 24 hours of birth. Hematocrit values, serum glucose and urea concentrations at 24 hours and 5 days of age were unaffected by treatment. Serum total proteins were 14% higher (P < 0.05) in the unsuplemented group than in the supplemented group at 5 d of age. There was no significant difference between the supplemented and unsupplemented kids in daily weight gain from birth to 70 days of age (92 ± 4.8 vs 102 ± 5.1 g day⁻¹). Mortality was 4% for kids receiving the colostrum supplement as compared with 0.0% for kids ingesting maternal colostrum only. Results suggest that, in intensively managed non-dairy goats with kiddings in summer, the supplementation of this commercial colostrum derived from cow lacteal secretions and containing antibodies against diverse pathogens organisms did not enhanced growth, survival or immunity under the farming conditions of this study.     

胡萝卜品种及栽培模式对比试验初报

为提高喀什地区胡萝卜产量及品质,在春播胡萝卜上选择沁黄胡萝卜、红胡萝卜、黄胡萝卜3个品种进行比较试验,结果表明黄胡萝卜适应性好、产量高、品质好。在复播胡萝卜上开展了小畦条播、小畦撒播、起垄条播和起垄撒播4种栽培模式对比试验,结果表明适于我区胡萝卜生产的最佳栽培模式为起垄撒播。     

植物毛状根的诱导及应用

发根农杆菌(Agrobacterium rhizogenes)诱导植物细胞的快速生长并分化形成毛状根,具有增长速度快、遗传稳定的特点。植物毛状根作为转基因工具被广泛地应用于次生代谢物的生产,环境污染的治理,以及作物品种改良等方面。本文主要从植物毛状根的诱导以及植物毛状根的应用两方面简要综述。同时对其潜在问题与未来发展前景做以展望,以期为毛状根在牧草方面的研究提供一些借鉴,并为草业科学研究领域提供一种新的技术手段。     

鸡蛋中硝基呋喃类代谢物残留检测UPLC-MS/MS法研究

建立了鸡蛋中硝基呋喃类代谢物（AOZ、AMOZ、AHD和SEM）残留检测的超高效液相色谱-串联质谱方法（UPLC-MS/MS）。样品在酸性条件下衍生化后,弱碱性条件下用乙酸乙酯提取后,用正己烷去除脂肪,高速离心去除蛋白质等杂质,上机测试。液相色谱条件：色谱柱为BEH C18（50×2.1mm,1.7μm）,流动相为甲醇+10mmol/L乙酸铵水溶液,梯度洗脱,流速为0.3 mL/min,柱温为30 ℃,进样量为10 μL。质谱条件：电喷雾离子源（ESI+）,多反应监测（MRM）方式进行采集。结果表明：硝基呋喃类代谢物在0.5~20 ng/mL浓度范围内均呈现良好的线性关系,相关系数（R2）均大于0.990;鸡蛋中四种代谢物的检测限均为0.25ng/g,定量限均为0.5ng/g。在0.5、1和5 ng/g三个添加浓度平均回收率为79.1％~109.4％,批内和批间RSD均小于20%。该方法具有简便快捷、灵敏度高、定性准确等特点。     

Application of Components Geographic Information System

Com GIS is a new gerneration GIS system.This article demonstrates the basic concepts and the technical features of Com GIS,and discussions on the secondary application developments of Com GIS system for the Geomedia platform are given as an example.     

蔬菜保护地土壤次生盐渍化的形成与防治

次生盐渍化是造成保护地土壤障碍的主要因素之一。有关保护地土壤次生盐渍化的研究一直受到各国学者的普遍重视。本文对保护地次生盐渍土的特性、成因及防治措施进行了综合评述。