Vitamin E-Gehalt der Kuhmilch in Abhängigkeit von der Grasfütterung im Tal und auf alpinen Weiden

Jeweils sechs laktierende Brown Swiss Kühe erhielten entweder reine Weidefütterung, reine Grünfütterung im Stall oder eine konventionelle Silage-Kraftfutter Vergleichsration. Dies wurde nacheinander für jeweils 42 Tagen an einem raigrasreichen Talstandort (400 m) und auf einer extensiven artenreichen Alpweide (2000 m) durchgeführt. Die Konzentration an Tocopherolen (Vitamin E)in der Milch wurde mittels HPLC bestimmt. Die Vitamin E-Konzentrationen waren in den grasbasierten gegenüber den aus der Vergleichsration stammenden Milchproben generell deutlich erhöht. Einen weiteren geringen Zusatzeffekt für den Tocopherolgehalt der Milch brachte die Alpweide, wobei jedoch aufgrund der geringeren Milchleistung die tägliche Menge an mit der Milch sekretiertem Vitamin E geringer war als auf der Talweide

A study on the causes for the elevated n−3 fatty acids in cows' milk of alpine origin

The influence of grass-only diets either from rye-grass-dominated lowland pastures (400 m above sea level) or botanically diverse alpine pastures (2000 m) on the FA profile of milk was investigated using three groups of six Brown Swiss cows each. Two groups were fed grass-only on pasture (P) or freshly harvested in barn (B), both for two experimental periods in the lowlands and, consecutively, two periods on the alp. Group C served as the control, receiving a silage-concentrate diet and permanently staying in the lowlands. Effects of vegetation stage or pasture vs. barn feeding on milk fat composition were negligible. Compared with the control, α-linoleic acid (18∶3n−3) consumption was elevated in groups P and B (79%, P<0.001) during the lowland periods but decreased on the alp to the level of C owing to feed intake depression and lower 18∶3n−3 concentration in the alpine forage. Average 18∶3n−3 contents of milk fat were higher in groups, P and B than in C by 33% (P<0.01) at low and by 96% (P<0.001) at high altitude, indicating that 18∶3n−3 levels in milk were to some extent independent of 18∶3n−3 consumption. The cis-9,trans-11 CLA content in milk of grass-fed cows was higher compared with C but lower for the alpine vs. lowland periods whereas the trans-11, cis-13 isomer further increased with altitude. Long-chain n−3 FA and phytanic acid increased while arachidonic acid decreased with grass-only feeding, but none of them responded to altitude. Grass-only feeding increased milk α-tocopherol concentration by 86 and 134% at low and high altitude (P<0.001), respectively. Changes in the ruminal ecosystem due to energy shortage or specific secondary plant metabolites are discussed as possible causes for the high 18∶3n−3 concentrations in alpine mil

Tracing the fate of 15N-labelled animal manure in the environment

Background • Nitrate leaching threatens both the environment and drinking water quality • Switzerland ca. 380,000 ha with > 25 mg nitrate/L in groundwater (quality criteria for drinking water) [1]; the Gäu region (Canton Solothurn) is especially vulnerable • Organic fertilizers (slurry, farmyard manure, etc.) might entail considerably increased leaching risks due to variable nitrogen (N) content and availability • Aim: increase N use efficiency, simultaneously reduce leachin

Bekämpfung von Fusarien mit antifungalen Pflanzenprodukten und deren Effekte auf den Mykotoxin-Gehalt von Weizen

Fusarium graminearum (FG) is the most prevalent Fusarium Head Blight (FHB) fungus in Switzerland. In conventional agriculture, fungicides are used to reduce the risk of FHB infection and mycotoxin contamination of wheat. As an alternative for organic wheat production, we examined plant-based products that showed antifungal effects from our previous late blight field trials. In bioassays, the effect of these antifungal plant preparations (APP) was screened against FG. In 2006 and 2008, the most active APP, Rheum palmatum, Frangula alnus and preparations of Galla chinensis as well as a plant substance (PSX), were used as FHB control agents in field trials with artificial FG infections. In both years, FG incidence and deoxynivalenol content were significantly reduced by the APP. In 2006, the reduction was in the same dimension as applications with Pronto Plus®, a fungicide mixture of tebuconazole and spiroxamine

Significance of Coprophagy for the Fatty Acid Profile in Body Tissues of Rabbits Fed Different Diets

Four groups of eight New Zealand hybrid rabbits were fattened with ad libitum access to the following pelleted experimental diets: ryegrass meal or alfalfa meal fed either alone or with oats meal in a ratio of 1:1. After 25weeks they were slaughtered and dissected. Fatty acid (FA) profiles of caecotrophs (re-ingested fermentation products of the caecum), perirenal adipose tissue and intramuscular fat in the Musculus quadriceps were determined. With high proportions of branched-chain FA (BFA) and trans FA, and increased proportions of saturated FA relative to the diets, the caecotroph FA profile showed a clear fingerprint of anaerobe microbial lipid metabolism including biohydrogenation. By contrast, the FA profiles of adipose and lean tissue comprised high proportions of polyunsaturated FA (PUFA), whilst BFA and trans FA occurred in much lower proportions compared to the caecotrophs. Thus, coprophagy did not substantially modify the FA composition of the tissues investigated. Use of forage-only diets, compared to the oats supplemented diets, led to extraordinary high proportions of n-3 PUFA (including 18:3 and long-chain n-3) in the fat of adipose (21.3 vs. 6.7%) and lean tissue (15.4 vs. 5.7%). The forage type diet (grass vs. alfalfa) had smaller effects on the FA profiles. Indications of diet effects on endogenous desaturation, chain elongation and differential distribution of functional FA between the two tissues investigated were foun

Raufutter als Alleinfutter für Kaninchen – Auswirkungen auf das Fettsäurenmuster des Fleisches

Four groups of eight New Zealand hybrid rabbits were fed ryegrass meal only, alfalfa meal only, ryegrass and oats 1:1, or alfalfa and oats 1:1. Diets were offered ad libitum in pelleted form from 5-30 weeks of age, when they were slaughtered. Intramuscular fatty acid profiles were determined in the Musculus quadriceps of the left hindleg. Feed intake was not statistically different between the four groups, nor was carcass weight. The main effect of the forage-only diets on the fatty acid profiles was a decrease of monounsaturated and an increase of polyunsaturated fatty acid (PUFA) proportions. Within PUFA, the n-3 fatty acids more than doubled with forage-only compared to forage-oats diets, while the n-6 fatty acids slightly decreased. In general, the proportion of n-3 fatty acids in intramuscular fat of forage-only fed rabbits was extraordinarily high compared to any other meat of agricultural origin. The results demonstrate a specific advantage of roughage-based diets in the nutrition of productive herbivores, which is also known for ruminants

Environmental Exposure to Estrogenic and other Myco- and Phytotoxins

Zearalenone (ZON) is known as a very potent, naturally occurring estrogenic mycotoxin. It is one of the most prevalent mycotoxin produced as a secondary metabolite by Fusarium species growing on cereals such as wheat and corn. It has been studied extensively in food and feed products for decades but only rarely and somewhat by chance in the environment. We therefore elucidated its agro-environmental fate and behavior by conducting a series of field studies and monitoring campaigns. Specifically, ZON was investigated in plants, soils and drainage waters from wheat and corn fields artificially infected with Fusarium graminearum. In addition, manure, sewage sludge and surface waters were analyzed for ZON. Three main input pathways of ZON onto soil could be identified: i) wash-off from Fusarium-infected plants (in the order of 100 mg/ha), ii) plant debris remaining on the soil after harvest (up to few g/ha), and iii) manure application (in the order of 100 mg/ha). Our results show that these input sources altogether caused the presence of several g/ha of ZON in topsoil. Compared to this, ZON emission by drainage water from Fusarium-infected fields was generally low, with maximum concentrations of 35 ng/l and total amounts of a few mg/ha. Due to dilution, ZON concentrations dropped below environmental relevance in larger surface water bodies. However in small catchments dominated by runoff from agricultural land, ZON might substantially contribute to the estrogenicity of such waters. Apart from ZON, other natural toxins monitored in this study, such as the mycotoxin deoxynivalenol or the estrogenic phytoestrogen formononetin, emitted to and occurred in surface waters at considerably higher amounts. To date their ecotoxicological effects are largely unknown

Similar distribution of 15N labeled cattle slurry and mineral fertilizer in soil after one year

Targeted use of animal manures as a nitrogen (N) fertilizer is challenging because of their poorly predictable N fertilizer value. An enhanced understanding of their N transformation processes in soil under field conditions is necessary to better synchronize N availability and crop N demand. 15N labeled cattle slurry, produced by feeding a heifer with 15N labeled ryegrass hay, was used in an on-farm trial on two neighboring fields, cropped with maize or grass-clover, in order to assess crop N uptake and N dynamics in the topsoil. Recovery of applied total N in plant biomass was higher for mineral fertilizer (Min) (45–48%) than for slurry (Slu) (17–22%) when applied at the same rate of mineral N. Also, N derived from fertilizer in plant biomass was higher for Min than for Slu, due to both greater NH3 emissions and greater initial immobilization of slurry N. Despite initial differences between the two in the relative distribution of residual fertilizer N in soil N pools, already in the following spring the majority (77–89%) of residual N from both fertilizers was found in the non-microbial organic N pool. Of the applied total N, 18–26% remained in the topsoil after the first winter for Min, compared to 32–52% for Slu. Thus, the proportion of fertilizer N not taken up by the first crop after application, enters the soil organic N pool and must be re-mineralized to become plant available

Combined biological and chemical assessment of estrogenic activities in wastewater treatment plant effluents

Five wastewater treatment plant effluents were analyzed for known endocrine disrupters and estrogenicity. Estrogenicity was determined by using the yeast estrogen screen (YES) and by measuring the blood plasma vitellogenin (VTG) concentrations in exposed male rainbow trout (Oncorhynchus mykiss). While all wastewater treatment plant effluents contained measurable concentrations of estrogens and gave a positive response with the YES, only at two sites did the male fish have significantly increased VTG blood plasma concentrations after the exposure, compared to pre-exposure concentrations. Estrone (E1) concentrations ranged up to 51ngL−1, estradiol (E2) up to 6ngL−1, and ethinylestradiol (EE2) up to 2ngL−1 in the 90samples analyzed. Alkylphenols, alkylphenolmonoethoxylates and alkylphenoldiethoxylates, even though found at µgL−1 concentrations in effluents from wastewater treatment plants with a significant industrial content, did not contribute much to the overall estrogenicity of the samples taken due to their low relative potency. Expected estrogenicities were calculated from the chemical data for each sample by using the principle of concentration additivity and relative potencies of the various chemicals as determined with the yeast estrogen screen. Measured and calculated estradiol equivalents gave the same order of magnitude and correlated rather well (R 2=0.6

Contribution of diet type and pasture conditions to the influence of high altitude grazing on intake, performance and composition and renneting properties of the milk of cows

Individual factors contributing to the influence of high altitude grazing on milk synthesis and quality were investigated in three groups of six cows each. After an initial period, where all cows received a silage-concentrate control diet, two groups were offered only grass further on, the third received the control diet and stayed in the barn in the lowlands. Grass-fed cows were either kept on pasture or in barn and were subjected to four experimental periods, two of them at 400 m a.s.l. and two at 2000 m a.s.l. Young and mature swards were grazed consecutively at each altitude. In the lowlands, feeding grass instead of the control diet did not clearly affect intake and performance but increased dietary N conversion ratio into milk protein and casein number. Relative to the control, rennet coagulation properties of the milk were improved on pasture but not with grass fed in barn. At the alpine site, nutrient and energy intake was depressed during the entire alpine period, presumably because of a combination of decrease in intake related to hypoxia and lower digestibility of the grass. Indications for elevated maintenance energy requirements caused by high altitude and, less so, by grazing activity were found. Compared to lowland, milk yield, milk protein content and N utilisation were lower at high altitude. Curd firmness was impaired by high altitude grazing at unchanged rennet coagulation time. The effects of grass maturity remained low at both altitudes despite contrasting digestibilities measured in young and mature swards. The plasminogen-derived activity in the milk declined with increasing sward maturity and with altitude, while plasmin activity was increased by sward maturity. Overall, diet type (control vs. alpine grass) and hypoxia-related factors seem to be more important for the expression of the known effects of alpine summer grazing than grazing activity as such and maturity of the sward.Contribution du type de ration et de la maturité des fourrages à l'influence d'un séjour au pâturage à haute altitude sur les quantités d'aliments ingérées, la quantité de lait produite et sa composition ainsi que ses propriétés de coagulation chez les vaches laitières. Les facteurs individuels contribuant à l'influence du pâturage à haute altitude sur la quantité de lait produite et sa qualité ont été analysés avec trois lots de six vaches chacun. Après une période initiale, où toutes les vaches ont été nourries avec une même ration témoin composée d'ensilage et de concentré, deux lots ont reçu uniquement de l'herbe et le troisième une ration témoin, à l'étable, en plaine. Les vaches alimentées avec l'herbe ont été gardées soit au pâturage, soit à l'étable, et étaient exposées à quatre périodes expérimentales, deux d'entre elles à 400 m d'altitude et deux à 2000 m. Des pâturages jeunes ou matures ont été offerts consécutivement à chaque altitude. En plaine, le remplacement de la ration témoin par de l'herbe n'a affecté ni les quantités ingérées ni les performances mais a augmenté le taux de conversion de l’azote alimentaire en protéines du lait et le rapport caséines/protéines. Par rapport à la ration témoin, les propriétés de coagulation du lait ont été améliorées au pâturage, mais pas avec l'herbe distribuée à l'étable. En montagne, l'ingestion de nutriments et d'énergie a été plus faible durant toute la période expérimentale, vraisemblablement en raison de la combinaison de deux facteurs : la baisse de consommation liée à une hypoxie et la faible digestibilité de l'herbe. Des indications montrant les besoins énergétiques d'entretien élevés causés par la haute altitude et l'activité de pâturage ont été trouvées. Comparées à la plaine, les performances laitières, les teneurs en protéines du lait et l'utilisation de N ont été plus basses à haute altitude. La fermeté du caillé a été plus faible à haute altitude pour des temps de coagulation inchangés. Les effets de la maturité de l'herbe sont restés faibles aux deux altitudes malgré des digestibilités différentes entre les pâturages jeunes et matures. Dans le lait, l'activité dérivée du plasminogène a diminué avec l'augmentation de la maturité du fourrage et avec l'altitude, alors que l'activité de la plasmine augmentait avec l'âge du fourrage. Dans l'ensemble, le type de ration (témoin vs. herbage alpin) et les facteurs liés à l'hypoxie semblent être plus importants pour l'expression des effets connus du pâturage en montagne que l'activité de pâturage en soi ou l'âge du fourrage