Estrogen induction of fatty liver in dairy cattle

Two trials were conducted to determine if estrogen contributes to development of fatty liver in dairy cattle. During trial 1, eight late lactation, nonpregnant cows were assigned to 0 or 15 mg estradiol-17 beta benzoate/d treatment. Days 1 to 3 of the trial were for baseline measurements, and treatments were given from d 4 to 21; on d 20 and 21 animals were fasted. Short-term feed deprivation resulted in increased plasma FFA concentrations and rapid accumulation of triglyceride into liver tissue obtained by biopsy. During starvation, plasma FFA concentration and liver triglyceride content were lower for cows receiving the estradiol-17 beta treatment relative to cows receiving control treatment. Very low density lipoprotein concentration in blood increased dramatically in three of four animals during estradiol-17 beta administration. Because of the decrease in milk production during estradiol-17 beta treatment, it was not known whether this represented a decrease in very low density lipoprotein clearance from blood or reflected a lipotropic response to estradiol-17 beta. Therefore, a second trial was conducted employing nonlactating cows, and control and estradiol-17 beta-treated animals were pair fed. The trial was 33 d with d 1 to 3 for baseline measurements, and treatments were administered from d 4 to 33. All animals were starved from d 19 to 23. Estradiol-17 beta increased hepatic lipid and triglyceride accumulation and plasma very low density lipoprotein concentration during starvation. Plasma FFA concentration was also increased by estradiol-17 beta during this time; therefore, a direct or indirect effect of estrogen on hepatic lipid metabolism could not be delineated.     

Yield and vitamin C content of tomatoes grown in vermicomposted wastes

Increasing quantities of earthworm digested materials (vermicompost) are being marketed as a peat‐free growth medium for amateur and professional food producers. Several studies indicate that growing tomatoes in peat mixed with low concentrations of vermicompost (10–20% by volume) produced by the earthworm Eisenea fetida increases yield of plants and marketability of fruits. Here we examined the effect of substituting commercial peat‐based compost with four different vermicomposts produced by the earthworm Dendrobaena veneta. Vermicompost was added to peat‐based compost at rates of 0%, 10%, 20%, 40% and 100% (v/v) and the following characteristics of tomato (Lycopersicon esculentum var. Money maker) assessed: germination, yield, marketability, fruit weight and ascorbic acid concentration. Vermicompost significantly increased germination rates (176%) and improved the marketability of fruits at 40% and 100% substitution rates due to the lower incidence of physiological disorders ('blossom end rot' and fruit cracking). Total fruit yield, marketable fruit yield, fruit number, individual fruit weight and vitamin C concentration were unaffected by the presence of vermicompost. Although vermicompost may provide a viable alternative to peat‐based growth media, overall, we found little added benefit from using vermicompost. We conclude that some of the previously reported benefits of vermicompost on horticultural production may be overstated and that marketing strategies should reflect this in order to preserve consumer confidence in vermicompost products. Copyright © 2007 Society of Chemical Industry     

Nutritive value of potato processing wastes in total mixed rations for dairy cattle

The nutritive value of wet potato processing waste for dairy cattle was determined in two experiments. In Experiment 1, rations contained, on a dry matter basis, 0, 10, 15, and 20% potato waste and were substituted for high moisture corn in diets for 32 lactating Holstein cows for 12 wk. Substituting potato waste for corn did not significantly affect milk yield, milk composition, milk production persistency, or dry matter intake. Cows fed 20% potato waste tended to decrease in milk fat percent and to shift molar proportions of rumen volatile fatty acids toward a decrease in acetate: propionate ratio. In Experiment 2, six steers were used in a 3 X 3 Latin square design to test digestibility and nitrogen utilization of potato waste substituted for high moisture corn at 0, 10, and 20% of the ration dry matter. A second group of four steers with rumen fistulas were used in a 4 X 4 Latin square to test rumen fermentation parameters. Diets contained 0, 10, 20, and 30% potato wastes and were similar to Experiment 1. Potato waste did not significantly affect digestibility of crude protein or dry matter, but at 20% substitution digestibility of acid detergent fiber decreased. Rumen ammonia, acetate, acetate to propionate ratios, and total volatile fatty acids were lower at high intakes of potato waste and pH was increased. The shift in rumen fermentation when large amounts of potatoes were fed explains the depressed butter fat on these rations.     

Cholesterol content and lipid composition of low fat dairy products

The lipid composition of different products obtained from the same raw milk was investigated. The cholesterol content of skim milk (0.05% total fat) and butter milk (0.57% total fat) lipids was 4.20% and 1.31%, respectively, while raw milk lipids and butter fat contained 0.34% or 0.30%, respectively. As the cholesterol content of these low fat milk products increases with decreasing fat content, equations were derived to estimate the fat-related cholesterol content from the value analysed in butter fat. In contrast to the fat-related cholesterol content, the product-related content is still relatively small in skim and butter milk. Their fat-related cholesterol content was found to be influenced by drying. The high content of phospholipids in skim and butter milk led to considerable changes in the fatty acid composition and affected the detection of foreign fat by butyric acid as well as by triglycerides. Skim and butter milk lipids contained only 2.41% or 2.33% butyric acid, respectively, instead of 3.36% found in raw milk lipids. Further, the overlap of phospholipids as well as cholesterol with the gas chromatographic triglyceride pattern resulted in calculated foreign fat contents of more than 20%.     

云南特产乳扇中铝含量调查分析

目的了解云南省乳扇中铝含量状况。方法在乳扇主要产地和主要消费市场的家庭作坊、零售店、农贸市场,随机采集50份样品,采用国家统一的标准监测方法对铝含量测定。结果 50件乳扇样品铝平均含量为2011 mg/kg,最高值为10261 mg/kg,最低值10 mg/kg。50件乳扇样品中有70%样品(35件)铝的含量100 mg/kg。家庭作坊、零售店、农贸市场样品数据无显著性差异。结论云南乳扇中存在铝含量过高的情况,应引起足够的重视。     

共轭亚油酸的生理功能及提高其在乳制品中含量的途径

概述共轭亚油酸(CLA)的生理功能,及提高其在乳制品中CLA的途径,如选育高产CLA的动物品种、研发新饲料、控制和改进加工条件等.     

Measures of bone mineral content in mature dairy cows

The objectives of this investigation were to assess the relationship between chemical measures and imaging estimates (radiographic photometry and dual-energy x-ray absorptiometry) of bone mineral content in dairy cows and to evaluate the effects of parity, stage of lactation, and site of measurement (fused third and fourth metacarpal bone vs. caudal vertebrae 14 and 15) on bone mineral content. In a preliminary study, the caudal vertebrae were excised from 33 cows following slaughter. Samples were analyzed by radiographic photometry and then analyzed for mineral content chemically. In a second experiment, the caudal vertebrae and right front metacarpal (sample pairs) were excised from 107 Holstein cull cows following slaughter. Parity and days in milk (DIM) of the donor animals were obtained for 43 pairs of samples. Samples were grouped by parity (1, 2, 3, and >or=4) stage of lactation (Stage 1: <90 DIM, Stage 2: 90 to 150 DIM, Stage 3: 151 to 250 DIM, and Stage 4: >250 DIM). Samples were analyzed by radiographic photometry and dual-energy x-ray absorptiometry and then analyzed for mineral content chemically. In both experiments, the relationship between mineral content estimated via the imaging techniques and mineral content measured chemically was poor, likely because of the relative maturity of animals in the sample set and lack of variation in mineral content. Ash content was higher in the metacarpal than in the caudal vertebrae, as were concentrations of Mg (expressed as a proportion of bone ash). No effects of stage of lactation were observed on bone mineral in the caudal vertebrae, but in the metacarpal, P content (proportion of total mineral) was highest in second lactation cows. Total bone mineral content (ash) was not affected by parity in the metacarpal or caudal vertebra, but Ca and P content of the metacarpal increased with parity. Noninvasive imaging techniques are not sufficiently sensitive to detect changes in mineral content or composition of mature cows, and only modest changes in bone mineral were observed with stage of lactation and parity.     

The effect of commonly used dairy processing techniques and unit operations on the equol content of dairy products

Since a large portion of the milk consumed by human is processed, the aim of this study was to determine possible changes in equol content upon processing milk. Individual milks with different levels of equol content were collected from the morning milking to make skimmed milk and cream, as well as pasteurised and sterilised full fat milks. Pasteurised milk was further processed into yoghurt, kefir, cottage cheese and whey. Yoghurt and kefir were also produced from sterilised milk. Equol content was not affected by either pasteurisation or sterilisation. Compared with raw milk, a higher concentration of equol was measured in skimmed milk, but equol content in cream was lower. The concentration of equol remained unchanged after yoghurt production but was reduced by more than 50% after kefir production. The equol content in whey was low compared with that of raw milk, while it increased sharply in cottage cheese.     

奶山羊乳房炎抗氧化性微量元素质量浓度的变化

为探讨奶山羊泌乳期乳房炎抗氧化性微量元素质量浓度的变化,实验测定了乳房炎奶山羊血清和乳腺组织中的Se,Zn,Cu的质量浓度.结果表明,患病奶山羊血清和乳腺组织中Se和Zn质量浓度明显低于正常对照组(P<0.05,P<0.01),Cu含量高于正常对照组(P>0.05).患病奶山羊血清和乳腺组织中Se和Zn质量浓度的减少降低了抗氧化能力及机体抵抗力,铜质量浓度升高的机理目前尚不十分清楚.     

Studies on iodine content in daily diets and selected dairy products

Poland's people have moderate – and in seaside areas mild – degrees of severity of iodine deficiency. A national program has been introduced for obligatory iodine prophylaxis and includes the iodination of household salt to the extent of 30 ±10 mg KI/kg. In order to assess the extent of iodine consumption, analytical studies were carried out on iodine content in average Polish diets. Taking into account the fact that milk formulae are frequently the basic source of iodine for infants, studies were performed on the iodine content in selected dairy products, mainly infant formulae. Iodine concentrations in samples were determined in duplicate by radioactive neutron activation analysis (RNAA). The iodine content in Polish diets without added iodinated kitchen salt was low and insufficient to provide the Polish RDA for this element. The results of the analytical investigations of the daily diets showed higher iodine content in comparison to theoretical calculations. The theoretical values accounted for 71–85% of the analytical ones. Study of iodine content in infant formula demonstrated differences between the analytically determined iodine content in products and that declared by producers. Received: 22 November 1999     

乳脂肪分析仪检测乳及乳制品中脂肪含量

目的采用乳脂肪分析仪测定乳与乳制品中脂肪的含量,并与国家标准方法比对。方法以国家标准GB5009.6-2016的第三法碱水解法为依据,对样品进行在线碱水解,再用无水乙醚和石油醚抽提样品的水解液,通过蒸馏去除溶剂,最后测定溶于溶剂中的抽提物的质量,用乳脂肪分析仪测定乳及乳制品中脂肪的含量。结果本方法可检测不同食品中脂肪含量,平均回收率为97.5%,其重复性相对标准偏差(relative standard deviation, RSD)值(n=6)分布在0.08%～1.24%之间。用仪器法和国标法同时检测质控样品,其回收率和RSD结果显示仪器法优于国标法。结论乳脂肪分析仪集在线恒温水解、搅拌、分层、抽提于一体,操作简便快捷,结果准确,适用于乳与乳制品中脂肪的测定。     

Biogenic amine content of kefir: a fermented dairy product

Kefir is a fermented dairy product. Ten samples of kefir supplied from different manufacturers in Turkey were analyzed for the first time to determine biogenic amine contents using HPLC with benzoyl derivatization. Of the 10 biogenic amines under study, putrescine, cadaverine and spermidine were detected in all samples. Tyramine was detected in all kefir samples except one. Tyramine was the prevailing biogenic amine. Tyramine concentrations of kefir samples changed from non detectable values to 12.8 mg/l. Total biogenic amine contents of kefir samples were between 2.4 and 35.2 mg/l. Concentrations of biogenic amines were far below the allowable limits. pH values of kefir samples were in the range from 4.11 to 4.53; acidities were in the range from 0.652 to 1.047% (as lactic acid, w/v); total dry matters were from 8.88 to 12.00% (w/w); total free amino acid contents were from 0.0070 to 0.0206% (as leucine, w/v). No significant correlations were detected between biogenic amine concentrations and pHs and total dry matter contents. Significant correlations were obtained between biogenic amine concentrations and acidities and total free amino acid contents of kefir samples.     

微波消解-原子荧光光谱法测定乳与乳制品中的砷

建立用氢化物原子荧光法测定乳与乳制品中的砷,研究前处理方法和原子荧光仪器对实验结果的影响,最后确定消解试剂为3:2的硝酸和双氧水,微波消解最高温度为180℃,消解时间为25 min,且无需赶酸直接定容上级检测;原子荧光的还原荆为15 g/L的硼氢化钾,栽流液为5%的盐酸.用以上最优化条件对乳与乳制品进行测定,得到砷的检出限为0.029μg/L,相对标准偏差为1.2%,回收率范围为93%～108%.     

真空包装条件下不同水分含量乳扇的品质变化

通过对真空包装的不同水分含量（质量分数）乳扇在储藏过程理化、微生物指标进行测定，研究了真空包装条件下不同的水分含量（质量分数）对乳扇储藏品质的影响及各项指标之间的柏关性。姥果表明：所含不同水分质量分数的乳扇经真空包装储藏半年后．微生物的生长繁殖受到了抑制，保质期延长；乳扇的水分质量分数为7．00％-7．50％，贮藏品质最佳；水分活度和pH值对菌落总数的影响具有显著的线性关系。     

Minor and trace element content of two typical Italian sheep dairy products

The concentration ranges in milk and cheese of a number of metallic elements relevant to the health of the consumer are dependent upon animal species, feeding, time of year, environmental conditions and manufacturing processes. We have measured the concentrations of selected trace elements--Al, Ba, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Pt, Sr and Zn--in raw ewes' milk and typical ewes' milk cheeses. Samples of milk, curd, whey, cheese after moulding, cheese after salting, commercial cheese (Pecorino), Ricotta, scotta and brine were analyzed for seven complete cycles of cheese production. Samples of curd, whey, brine and waste product (i.e. scotta) were collected and analysed in addition to the cheese and milk to assess the distribution of each element in the main product, by-products and waste products during cheesemaking. Quantitative determinations were performed mainly by inductively coupled plasma atomic emission spectrometry. There were considerable differences among the trace element contents of raw ewes' milk and related products, indicating that manufacturing processes play a key role in the distribution of minor and trace elements. Two different approaches were used to assess the dietary intake of these elements associated with the consumption of Pecorino and Ricotta, and whether this had any nutritional or toxicological implications. The results indicated no toxicological risk and showed that, on the contrary, Pecorino may be a good source of several essential elements.     

碱水解法测定乳及乳制品中脂肪的含量

目的建立简单、快速的碱水解法测定乳及乳制品中脂肪的含量。方法取0.5 g样品于离心管中,用10 mL纯水复溶后加入2 mL氨水(25%)水解并65℃水浴20 min。加入乙醇沉淀蛋白质并使用乙醚、石油醚提取样品中脂肪。将上清液提取至收集瓶中,蒸干提取液,称量收集瓶前后质量,计算样品中脂肪含量。结果此法测得样品脂肪含量为26.53 g/100 g,结果相对偏差为0.37%。测定值在质控样品值满意区间内,且符合国标规定的两次独立测定结果之差≤0.3 g/100 g的要求。结论本法测定乳及乳制品中脂肪的含量具有简便、快速、重现性好的优点,适合实验室日常样品测定及考核使用。     

Evaluation of methods for recovery of Salmonella from dairy cattle, poultry, and swine farms

Current official methods for detection and isolation of Salmonella are mostly designed for foods. The objective of this study was to determine optimal methods for detection and isolation of Salmonella from animal and environmental samples of dairy, poultry, and swine farms. Preenrichment in lactose broth versus direct enrichment (no preenrichment) prior to selective enrichment in Rappaport-Vassiliadis, selenite cystine, and tetrathionate incubated at 35 and 42 degrees C and in four differential/selective plating media (brilliant green, bismuth sulfite, Hektoen enteric, and xylose-lysine-tergitol 4 agar base) were evaluated for their ability to recover Salmonella from artificially contaminated samples. The effects of pH adjustments to samples on Salmonella recovery were determined. A pH adjustment of the enrichment broth to 6.8 +/- 0.2 after addition of samples significantly improved recovery of Salmonella. The most effective medium combinations for isolation of Salmonella from farm samples depended on the type of samples. Generalizations of protocols for recovery of Salmonella from farm samples might result in poor recovery, increased recovery time, and increased sample processing costs.     

Chemistry of swine liver and products of liver processing. 1. Carbohydrate content of swine liver in relation to thermal stress

Glucose can be extracted from the carbohydrates of pig liver by water, but glycogen only by boiling alkalies. The last one can be precipitated with ethanol. The boiling of an aqueous liver suspension causes a decrease in glucose quantity as expected. Thereby the influence of the liver proteins on carbohydrate concentration becomes apparent as well as the interaction between both substances within the reaction of non-enzymatic browning. A series of storing experiments confirmed that neither freezing nor boiling temperatures can completely stop this reaction.     

离子色谱法检测硝酸盐亚硝酸盐前处理方法的研究

目的 利用离子色谱法检测乳及乳制品中亚硝酸盐、硝酸盐,在实际检测中用该国标方法在前处理样品时,存在沉淀样品不完全进而影响检测准确性、重复性不理想的弊端,为提高检测的准确性,缩小检测偏差,需对国标方法中样品的前处理改进。方法 样品经乙腈沉淀脂肪蛋白质后,采用相应的方法提取和净化,以氢氧化钾溶液为淋洗液,阴离子交换柱分离,电导检测器检测。以保留时间定性,外标法定量。结果 该方法克服了乳及乳制品GB5009.33-2010第三法检测检出限高及检测用时长,精密度低的的弊端。结论本方法适合于乳及乳制品定量测定。