Pasture allowance,duration, and stage of lactation—Effects on early and total lactation animal performance

Pasture availability in early spring can be limited due to climatic effects on grass production, increasing the likelihood of feed deficits in early lactation of spring-calving pasture-based systems. We hypothesized that restricting pasture allowance (PA) when animals are at peak milk production will have more negative implications on milk production compared with restricting animals before this period. A total of 105 cows were assigned to 1 of 7 grazing treatments from March 14 to October 31, 2016 (33 wk). The control treatment was offered a PA to achieve a postgrazing sward height > 3.5 cm and mean pasture allowance of 15.5 kg of dry matter per cow. The remaining treatments were offered a PA representing 60% of that offered to the control for a duration of 2 or 6 wk from March 14 (mid-March; MMx2 and MMx6), March 28 (end of March; EMx2 and EMx6), or April 11 (mid-April; MAx2 and MAx6). Within grazing treatment, animals were also assigned to 1 of 2 calving dates (early and late) based on days in milk (DIM) on March 14. Early calved (EC) cows were ≥36 DIM, while late calved (LC) were ≤35 DIM. Restricting PA for 2 and 6 wk reduced daily milk yield (?1.6 and ?2.2 kg/cow, respectively), cumulative milk protein yield (?4.0 and ?6.3 kg/cow, respectively), and cumulative milk solids yield (?5.8 and ?9.5 kg/cow, respectively) in the first 10 wk of the experiment. Daily milk yield was similar across the treatments at the end of the 33-wk period (16.8 kg/cow, average of all treatments), as was daily milk solids yield (1.40 kg/cow). Cows in the EC group produced less milk over the first 10 wk of the experiment (20.0 kg/cow per day) compared with the LC animals (22.1 kg/cow per day). However, body weight was greater (+15 kg/cow) in the EC animals compared with the LC, while body condition score was similar (2.85). This outcome indicates that animals that are restricted later in early lactation (circa onset of peak milk production) partition a greater proportion of available energy to maintenance, resulting in greater losses in milk production. These data indicate that despite the immediate reduction in milk production, restricting intake of grazing cows to 80% of that required to achieve spring grazing targets for postgrazing sward height for up to 6 wk may be used as a method of managing short-term pasture deficits on farm with minimal effects on total lactation performance.     

Dioxins,furans and non-ortho-PCBs in Canadian total diet foods 1992–1999 and 1985–1988

In the period from 1985 to 1999, about 600 samples of total diet foods from Canadian cites were analysed for dioxins, furans and non-ortho-PCBs. Toxic equivalent (TEQ) concentrations on a lipid basis were found to be the highest in dairy and beef products followed by poultry and pork. These levels decreased over the 15-year period of sampling, particularly those for fluid milk, less so for poultry and pork and little or no change for beef. Calculation of the human daily intake for the years 1985–1988 showed values a little less than 1?pg of TEQ₂₀₀₅ polychlorinated dibenzo-p-dioxin/polychlorinated dibenzofuran per kg body weight, falling progressively to less than 0.5?pg of TEQ in 1999. These estimates are lower than the 2.3?pg of TEQ currently recommended by the WHO. The main categories of foods contributing to the TEQ were animal meats and dairy products, with lesser amounts from fish and other foods.     

Impact of high pressure processing on total antioxidant activity,phenolic, ascorbic acid,anthocyanin content and colour of strawberry and blackberry purées

The present study was undertaken to assess the effect of high pressure treatments and conventional thermal processing on antioxidant activity, levels of key antioxidant groups (polyphenols, ascorbic acid and anthocyanins) and the colour of strawberry and blackberry purées. Bioactive compounds (cyanidin-3-glycoside, pelargonidin-3-glucoside, ascorbic acid) and antioxidant activity were measured in strawberry and blackberry purées subjected to high pressure treatment (400, 500, 600 MPa/15 min/10–30 °C) and thermal treatments (70 °C/2 min). Samples were assessed immediately after processing. Different pressure treatments did not cause any significant change in ascorbic acid (p > 0.05). In contrast, following thermal processing (P₇₀ ≥ 2 min) ascorbic acid degradation was 21% (p < 0.05) as compared to unprocessed purée. However, no significant changes in anthocyanins were observed between pressure treated and unprocessed purées (p > 0.05), whereas conventional thermal treatments significantly reduced the levels (p < 0.05). In general, antioxidant activities of pressure treated strawberry and blackberry purées were significantly higher (p < 0.05) than in thermally processed samples. Colour changes were minor (ΔE) for pressurised purées but the differences were slightly higher for thermally treated samples. Redness of purées was well retained in high pressure treated samples. Therefore processing strawberry and blackberry by high pressure processing could be an efficient method to preserve these products quality. Hence high pressure processing (HPP) at moderate temperatures may be appropriate to produce nutritious and fresh like purées.Industrial relevanceThis research paper provides scientific evidence of the potential benefits of high pressure processing in comparison to thermal treatments in retaining important bioactive compounds. Antioxidant activity (ARP), ascorbic acid, and anthocyanins after exposure to high pressure treatments (400–600 MPa) were well retained. Our results also show that redness and colour intensity of strawberry and blackberry purées were better preserved by high pressure processing than conventional thermal treatment. From a nutritional perspective, high pressure processing is an attractive food preservation technology and offers opportunities for horticultural and food processing industries to meet the growing demand from consumers for healthier food products. Therefore high pressure processed foods could be sold at a premium than their thermally processed counterparts as they will have retained their fresh-like properties.     

Seasonal changes in the total fatty acid composition of Vimba, Vimbavimba tenella (Nordmann, 1840) in Eğirdir Lake,Turkey

Total fatty acid compositions and its seasonal variations in Vimba, Vimba vimba tenella (Nordmann, 1840) in E?irdir Lake, which is the second largest freshwater lake in Turkey, were investigated by a gas chromatographic method. Twenty seven different fatty acids were determined in the composition of Vimba vimba tenella. Monounsaturated fatty acids (MUFAs) were found to be in higher amounts than saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs) in all seasons. Oleic acid (C18:1 n9) was the major MUFA in all seasons. Palmitic acid (C16:0) was identified as the major SFA in all four seasons. Arachidonic acid (C20:4 n6), docosahexaenoic acid (C22:6 n3), linoleic acid (C18:2 n6), and eicosapentaenoic acid (C20:5 n3) were at the highest levels among the PUFAs. In the present study, n-3/n-6 ratios were found to be 1.4,1.5,1.2 and 1.4 in spring, summer, autumn and winter, respectively. Vimba vimba tenella may be a valuable food for human consumption in terms of fatty acids.     

The Canadian total diet study design: 1992–1999

This paper describes the design of the fourth phase of the Canadian total diet study, conducted for the period 1992–1999. During this phase, complete sets of foods were purchased from eight cities (from one of them twice). For each of the sets, individual foods were prepared as for consumption into about 140 different food composites at Kemptville College, homogenised and bottled. Water from Kemptville, Ontario, was used for the preparation of the foods. The composites were stored frozen at??20°C and then analysed in the Food Research Division for chlorinated dioxins and dibenzofurans, pesticides, PCBs and trace elements. The analytical results were combined with average food consumption values for different age/sex groups, and dietary intakes were calculated. The design of the total diet study provided information to achieve the following goals: (a) background concentrations of the chemicals in the 140 different food composites, (b) average dietary intakes of the chemicals by the population and by different age/sex groups, (c) percent contribution of individual foods and food groups to the dietary intakes, (d) identification of individual contaminated foods and (e) identification of trends in human exposure with time.     

trehalose synthase was accounted for 15.2% of total soluble pro

.trehalose synthase;high cell-density fermentation;pH-stat国家“863”计划(AA214171)0食品工业科技Science and Technology of Food Industry120-123TS201.2B02431B;B024_31蒙健宗;125-128鸡蛋清中三种主要蛋白质的连续化提取分离研究宋宏新;梁艳;陕西科技大学生命科学与工程学院,陕西科技大学生命科学与工程学院 陕西咸阳712081,陕西咸阳712081卵白蛋白;;溶菌酶;;卵铁传递蛋白;;连续化提取对鸡蛋清进行微滤、超滤浓缩后,加入60%的饱和硫酸铵盐析,得到了卵白蛋白粗品;上清液用Q-sepharoseF.F.离子交换层析,分离得到溶菌酶和卵铁传递蛋白,从而实现了蛋清中三种蛋白质的连续化提取。Continuous isolaion of three main proteins from egg whiteSong HongxinOvalbumin was obtained by microfiltration,ultrafiltration and 60%(NH4)2SO4 salting-out of egg white;Ion-exchange chromato     

Food intake, milk production, and tissue changes of Holstein-Friesian and Jersey × Holstein-Friesian dairy cows within a medium-input grazing system and a high-input total confinement system

Although interest in crossbreeding within dairy systems has increased, the role of Jersey crossbred cows within high concentrate input systems has received little attention. This experiment was designed to examine the performance of Holstein-Friesian (HF) and Jersey × Holstein-Friesian (J × HF) cows within a high concentrate input total confinement system (CON) and a medium concentrate input grazing system (GRZ). Eighty spring-calving dairy cows were used in a 2 (cow genotype) × 2 (milk production system) factorial design experiment. The experiment commenced when cows calved and encompassed a full lactation. With GRZ, cows were offered diets containing grass silage and concentrates [70:30 dry matter (DM) ratio] until turnout, grazed grass plus 1.0 kg of concentrate/day during a 199-d grazing period, and grass silage and concentrates (75:25 DM ratio) following rehousing and until drying-off. With CON, cows were confined throughout the lactation and offered diets containing grass silage and concentrates (DM ratio; 40:60, 50:50, 40:40, and 75:25 during d 1 to 100, 101 to 200, 201 to 250, and 251 until drying-off, respectively). Full-lactation concentrate DM intakes were 791 and 2,905 kg/cow for systems GRZ and CON, respectively. Although HF cows had a higher lactation milk yield than J × HF cows, the latter produced milk with a higher fat and protein content, so that solids-corrected milk yield (SCM) was unaffected by genotype. Somatic cell score was higher with the J × HF cows. Throughout lactation, HF cows were on average 37 kg heavier than J × HF cows, whereas the J × HF cows had a higher body condition score. Within each system, food intake did not differ between genotypes, whereas full-lactation yields of milk, fat plus protein, and SCM were higher with CON than with GRZ. A significant genotype × environment interaction was observed for milk yield, and a trend was found for an interaction with SCM. Crossbred cows on CON gained more body condition than HF cows, and overall pregnancy rate was unaffected by either genotype or management system. In summary, milk and SCM yields were higher with CON than with GRZ, whereas genotype had no effect on SCM. However, HF cows exhibited a greater milk yield response and a trend toward a greater SCM yield response with increasing concentrate levels compared with the crossbred cows.     

Polyphenol oxidase,total phenolics and ascorbic acid changes during storage of minimally processed ‘California Wonder’ and ‘Quadrato d'Asti’ sweet peppers

A growing sector of ‘minimally processed’ vegetables market is represented by sweet peppers, whose quality may be affected by enzymatic activities. Among these, polyphenol oxidase leads to browning reactions, which is a major cause of quality loss. This research aimed at assessing the changes in PPO activity, total phenolics and ascorbic acid throughout a 30-days cold storage in minimally processed green (cv. ‘California Wonder’), yellow and red (cv. ‘Quadrato d'Asti’) sweet peppers. At day 0 PPO was active in red and yellow fruits but not in green ones, where it started to show relevant activity from the 3rd week of storage. At the end of the storage period (day 30), PPO activity was 1.36, 0.94 and 0.61 U/g d.m. in yellow, red and green peppers, respectively. Total phenols content was highest in green peppers, followed by red and yellow ones. In green fruits it increased up to the 3rd week of storage, decreasing afterwards, whilst in red and yellow fruits phenols content progressively declined after the 2nd week. Yellow fruits showed the highest ascorbic acid content, followed by red and green ones.Results confirm that green peppers ‘California Wonder’ are more suitable to minimal processing than yellow and red fruits.     

Dietary exposure to pesticide residues in Yaoundé: The Cameroonian total diet study

Dietary exposure to pesticide residues was assessed in Yaoundé, Cameroon, using the total diet study (TDS) method. Sixty-three composite samples, representative of the foods as consumed in Yaoundé, were collected, prepared, and analysed for residues of pesticides including organochlorine, organophosphorous, and pyrethroids. A multi-residue method was used with a limit of detection (LOD) of 0.005mgkg^?1. Additional analyses were performed for dithiocarbamates (LOD=0.050mgkg^?1), glyphosate (LOD=0.005mgkg^?1) and chlordecone (LOD=0.0008mgkg^?1) on certain composites samples. The overall contamination was low with 37 out of 46 pesticides below the LOD in all samples. The estimated upper bound (for values less than the LOD equal the LOD; and values less than the LOQ equal the LOQ) of the mean dietary exposures ranged from 0.24% (cypermethrin) to 3.03% (pirimiphos-methyl) of the acceptable daily intakes (ADIs) for pesticides for which at least one analysis was greater than the LOD. This study suggests a low dietary exposure to pesticide residues in Yaoundé.     

Dietary exposure to pesticide residues in Yaoundé: the Cameroonian total diet study

Dietary exposure to pesticide residues was assessed in Yaoundé, Cameroon, using the total diet study (TDS) method. Sixty-three composite samples, representative of the foods as consumed in Yaoundé, were collected, prepared, and analysed for residues of pesticides including organochlorine, organophosphorous, and pyrethroids. A multi-residue method was used with a limit of detection (LOD) of 0.005 mg kg(-1). Additional analyses were performed for dithiocarbamates (LOD=0.050 mg kg(-1)), glyphosate (LOD=0.005 mg kg(-1)) and chlordecone (LOD=0.0008 mg kg(-1)) on certain composites samples. The overall contamination was low with 37 out of 46 pesticides below the LOD in all samples. The estimated upper bound (for values less than the LOD equal the LOD; and values less than the LOQ equal the LOQ) of the mean dietary exposures ranged from 0.24% (cypermethrin) to 3.03% (pirimiphos-methyl) of the acceptable daily intakes (ADIs) for pesticides for which at least one analysis was greater than the LOD. This study suggests a low dietary exposure to pesticide residues in Yaoundé.     

Evaluation of total aflatoxin,nitrate and nitrite levels in layer feed samples of companies producing their own feed in Edincik and Bandırma province of Turkey

Feed contamination by fungi can lead to nutrient losses and detrimental effects on animal health and production. The presence of nitrates and nitrites in food can be harmful to both people and animals. The aim of this study was to determine total aflatoxin, nitrate and nitrite levels in layer feed samples from companies producing their own feed in Edincik and Band?rma provinces in Turkey and to discuss the potential risk to animal health. The results of the analyses indicated that mean total aflatoxin (AFT) ranged from 0.4 to 36.8?µg?kg^?1 and from 0.45 to 47.0?µg?kg^?1 in the year 2007 and the year 2008 samples, respectively. It was determined that nitrate levels were 2.4–10 and 1.7–13?µg?kg^?1 and that nitrite levels were 0–2.4?µg?kg^?1 and 0–2.6?µg?kg^?1 in these years, respectively. The levels of total aflatoxin, nitrate and nitrite in the layer samples could not be considered a risk to poultry health and productivity.     

Partial extraction method for the rapid analysis of total lipids and γ-oryzanol contents in rice bran

Total lipids and γ-oryzanol in rice bran were determined by a partial extraction method. The results agreed well with the conventional total extraction methods. The proposed method uses fewer hazardous organic solvents, takes a shorter extraction time and requires no special extraction apparatus. Total lipids and γ-oryzanol in nine rice bran varieties were analysed by the developed technique. Daw Dum 5647 had the highest total lipids and γ-oryzanol while the lowest content was found in KD XBT 313-19-1-1 and SP XBT 43-7, respectively. The adsorption coefficient (K_d) of the lipids and γ-oryzanol, between hexane and bran, at 30 °C are between 1.16 and 2.00 and 2.02 and 2.65, respectively (depending on the moisture content of the bran). From the K_d values, it was estimated that about 92–95% of the lipids and 95–96% of the γ-oryzanol were extracted into hexane at a 10:1 (v/w) ratio of hexane to bran. The effect of solvents on the extraction of γ-oryzanol from rice bran was also studied. It was found that isopropanol was the most suitable solvent for extraction and determination of γ-oryzanol in rice bran. It showed better agreement with the total extraction method.     

Analysis of seven folates in food by LC–MS/MS to improve accuracy of total folate data

An LC–MS/MS method for analyzing seven folates in food was developed and validated. 5-Methyltetrahydrofolate, 5-formyltetrahydrofolate, 10-formylfolic acid, tetrahydrofolate and folic acid were quantified using a stable isotope dilution assay (SIDA) with deuterated analogues as internal standards. Additionally, 10-formyldihydrofolate and 5,10-methenyltetrahydrofolate were quantified using deuterated internal standards different in structure. Due to interconversion of 5,10-methenyltetrahydrofolate to 5-formyltetrahydrofolate and 10-formyldihydrofolate to 10-formylfolic acid during sample preparation, a SIDA was not considered because of a resulting double calculation of the amounts interconverting. [²H₄]-5-methyltetrahydrofolate was used as internal standard for 5,10-methenyltetrahydrofolate, due to a similar retention time, and [²H₄]-10-formylfolic acid as well as [²H₄]-5-methyltetrahydrofolate was used for 10-formyldihydrofolate, because no internal standards co-elute. To confirm that no matrix effects affect the quantitation of 5,10-methenyltetrahydrofolate and 10-formyldihydrofolate, postcolumn infusion experiments were performed. Validation of the assay was accomplished by determining linearity, precision, recovery, limit of detection and limit of quantitation. The latter parameters were partly obtained by application of a dual-isotope label design including [¹³C₅]-labeled folates. The amounts of 5,10-methenyltetrahydrofolate in the purified extracts of different food samples ranged between 0.3 and 1.3 % and for 10-HCO-H₂folate between 0.05 and 8 % of the total folate amount. Correction for incomplete recovery of the latter folate during cleanup indicates even higher contents. Therefore, especially 10-formyldihydrofolate should not be neglected to obtain accurate results for folates.     

Effects of total surface area and fabric density on the acoustical behavior of traditional thermal‐bonded highloft nonwoven fabrics

Nonwoven fabrics are ideal materials for use in acoustical insulation products because they have a high total surface area, which is directly related to the denier and cross‐sectional shape of the fiber. The smaller the denier, the more fibers for the same material density, the higher the total fiber surface area is. This results in a greater opportunity for interaction between the sound wave and the fibers in the structure. Another important parameter is the density of the nonwoven material, which affects the geometry and the volume of the voids in the structure. The acoustical properties of fabric materials are measured using one of two methods: the impedance tube method and the reverberation room test method. The impedance tube method uses very small test samples (5–15 cm), whereas the reverberation room test method requires large test samples and is expensive to set up. For making comparative analysis of the test samples and overcoming the disadvantages of the current test methods, a direct comparative acoustical properties measurement device has been developed and fabricated in the School of Materials Science and Engineering at Clemson University in an attempt to overcome some of the disadvantages of the other method.     

Würzstoffe,Gewürze,Aromen, Essenzen,Kochsalz, Essig

European Food Research and Technology -     

混,剥,选,煮,缫连续化设备

介绍了混、剥、选、煮、缫连续化设备的三种总体布局形式，以及主要连续化设备和主要技术参数；阐明了采用该连续化设备的优点；该连续化设备及三种总体布局形式可供不同缫丝企业按需选用，是我国缫丝企业向现代化发展的必然趋势。