Abstracts der Tagung "Aktuelle Forschungsthemen des Biolandbaues" vom 06.04.05 an der FAL

Abstracts der Tagung "Aktuelle Forschungsthemen des Biolandbaues" vom 06.04.05 an der FAL - Ersatz von Kupfer im biologischen Kartoffelanbau: BLIGHT-MOP (2001-2005) Lucius Tamm und Bert Smit, FiBL (pdf-Datei, 4 MB) - Krankheiten und Schädlinge im Bio-Ackerbau Eindrücke von der 8. Wissenschaftstagung in Kassel – Ende der Nische? Hans-Rudolf Forrer, Agroscope FAL Reckenholz (pdf-Datei, 3 MB) - Anbaussysteme, Bodenfruchtbarkeit und Nährstoffversorgung im Bioackerbau Ausgewählte Themen der Tagungen von Kassel und Newcastle David Dubois und Jochen Mayer, Agroscope FAL Reckenholz (pdf-Datei, 1.8 MB) - Wo steht die Forschung zum pfluglosen Bio-Ackerbau? David Dubois, Agroscope FAL Reckenholz (pdf-Datei, 345 KB) - Systemversuch mit Bioackerbau am Standort Burgrain - Auswirkungen des Bioanbaus auf Boden, Ertrag,Biodiversität, Ökobilanz und Wirtschaftlichkeit Urs Zihlmann, Agroscope FAL Reckenholz und Ruedi Tschachtli, LBBZ Schüpfheim LU sowie weitere Mitwirkende von FAL, FAT und LBBZ (pdf-Datei, 1.4 MB) - Graslandsysteme: Beiträge zur 8. Wissenschaftstagung ökologischer Landbau 2005 ausgewählt, zusammengefasst und gewertet durch Andreas Lüscher, Agroscope FAL Reckenholz (pdf-Datei, 700 KB) - Qualitätssicherung im Biolandbau: EU-Projekt „OrganicHACCP“: Analyse kritischer Punkte in ausgewählten Wertschöpfungsketten Gabriela S. Wyss, FiBL (pdf-Datei, 1.3 MB) - Wo steht die Qualitätsforschung? Thomas Alföldi, FiBL (pdf-Datei, 1.4 MB) - Delphi Expertenumfrage im Bereich Verarbeitung von biologischen Lebensmitteln: Resultate der ersten Umfrage Ursula Kretzschmar und Otto Schmid, FiBL (pdf-Datei, 483 KB) - Herkunftsbestimmung von Käse mit Bio-Kulturen von ALP. Aktueller Stand - Perspektiven Daniel Wechsler, Agroscope ALP Posieux (pdf-Datei, 2.6 MB

Using plant wax markers to estimate the diet composition of grazing Holstein dairy cows

The objective of this study was to test whether diet selection of dairy cows under grazing conditions could be estimated using plant wax markers. Furthermore, differences between 2 cow strains and the effect of concentrate supplementation on plant species selection were investigated. The experiment was a study with a crossover design performed on an organic farm with 12 Swiss Holstein cows and 12 New Zealand Holstein cows. Both experimental periods consisted of a 21-d adaptation and a 7-d measurement period. All cows grazed full time in a rotational stocking system and received either no concentrate or 6 kg/d of a commercial cereal-grain mix. Representative herbage samples of each grazed paddock were taken and botanical composition of subsamples was manually determined. The average proportions of the plant species were 27.8% Lolium perenne, 6.1% Dactylis glomerata, 10.4% Trifolium repens, and 9.0% Taraxacum officinale. Other grass species were merged as "other grass" (38.2%) and other forb species as "other forbs" (8.5%). n-Alkanes, long-chain fatty acids, and long-chain alcohols (LCOH) were analyzed in the samples of plant species, concentrate, and feces from each cow. A linear discriminant analysis indicated that diet components were differentiated best with LCOH (96%) and worst with the combination of all marker groups together (12%). For each marker, the fecal marker recovery (FR) relative to dosed ytterbium was determined in 2 ways. Estimation of diet composition was performed with the software "EatWhat," and results were compared with botanical composition with the Aitchison distance. The results indicate that the diet composition of grazing dairy cows can be estimated using plant wax markers. Additionally, the calculation of FR led to mostly reliable results, yet this approach needs further validation. The most accurate estimation was achieved with the marker combination of n-alkanes and LCOH with a correction for FR. Less accurate estimations were achieved with long-chain fatty acids alone or in combination with n-alkanes. No difference relating to diet selection between the 2 cow strains was recorded, but supplemented cows apparently ingested higher proportions of T. repens than nonsupplemented cows. Awareness that supplementation influences selection behavior of grazing dairy cows may lead to adaptations in botanical composition of the pasture according to the demand of the animals

Influence of benzoic acid and phytase in low-phosphorus diets on bone characteristics in growing-finishing pigs

In 2 simultaneous experiments (Exp. 1 and Exp. 2), the effects of benzoic acid (BA) and phytase (Phy) in low-P diets on bone metabolism, bone composition, and bone stability in growing and growing-finishing pigs were examined. Experiment 1 was conducted with 16 crossbred gilts in the BW range of 25 to 66 kg of BW, whereas in Exp. 2, 32 crossbred gilts (25 to 108 kg of BW) were used. All pigs were individually housed in pens and restrictively fed 1 of 4 diets throughout the experiment. Total P content of the wheat-soybean diets was 4 g/kg (all values on an as-fed basis). The experimental diets were 1) unsupplemented control diet; 2) control diet with 0.5% BA; 3) Phy diet with 750 Phy units (FTU) of Phy/kg and no BA; and 4) PhyBA, control diet with 750 FTU of Phy/kg and 0.5% BA. Blood samples were taken at the beginning of the experiment, wk 3 (only for pigs in Exp. 1), wk 6, and before slaughter to determine P and Ca in serum and concentrations of total alkaline phosphatase, serum crosslaps (marker for bone resorption), and osteocalcin (marker for bone formation). Ash, P, and Ca contents of bones and bone stability were examined using the left metatarsal bones and tibia of the pigs after slaughter. Benzoic acid did not influence any of the blood variables (P > 0.09). The addition of Phy increased (P < or =0.03) P concentration in serum from 2.71 +/- 0.08 to 3.03 +/- 0.07 mmol/L at wk 3 and content of serum crosslaps from 0.39 +/- 0.02 to 0.45 +/- 0.02 ng/mL at wk 6 and decreased (P < 0.05) osteocalcin at wk 6 by 160 ng/mL. No long-term effect of diets on serum mineral concentrations, alkaline phosphatase, and bone markers in serum could be detected. Benzoic acid negatively affected (P < or = 0.03) Ca content in bones and distal bone mineral density, especially in the younger pigs. In the control diet with 0.5% BA and the control diet with 750 FTU of Phy/kg and 0.5% BA, the CA content in bones and distal bone mineral density were reduced by 6 and 11%, respectively. Throughout the whole growing and finishing period, Phy increased (P < or =0.02) ash, P, and Ca contents in bones by 29.4, 4.8, and 11.6 g/kg of DM, respectively. Bone mineral density and bone mineral content were greater in diets with Phy (P < or = 0.03), as well as breaking strength of tibia (+22%) and metatarsal bones (+27%; P < 0.01). The results of this study indicate that for a healthy skeleton, BA should not be used in low-P diets without the addition of Phy

Feeding transition cows with oilseeds: Effects on fatty acid composition of adipose tissue, colostrum and milk

The present investigation was aimed to test whether α-linolenic acid (ALA) concentrations in the adipose tissue can be increased by linseed feeding of dry cows and whether ALA is preferentially mobilized during the catabolic phase after parturition. The second objective was the determination of the influence of mobilization on fatty acid composition of colostrum and mature milk. For this purpose, four groups of six cows were fed diets supplemented either with crushed linseed (rich in ALA; two groups) or sunflower seed (rich in linoleic acid (LA)) or a 1:1 mixture of both for 6weeks. This supplementation was either kept post partum or switched shortly before calving from linseed or the mixture to sunflower seed. The post partum experimental period lasted for another 40d. Samples of blood were obtained in weeks −6, −2, 3 and 6 pre/post calving, those of backfat adipose tissue in weeks −2 and 6 pre/post calving (by biopsy) and milk samples on days 1, 2, 10, 20, 30 and 40 of lactation. Clear changes over time occurred in blood plasma metabolites and hormones as well as in body weight, body condition scores and backfat thickness, especially during the transition before and after calving. Milk yield and composition showed the typical time trends as well. Proportions of long-chain polyunsaturated fatty acids in the colostrum compared to the mature milk were clearly higher. This appeared similarly in all groups and was not influenced by the oilseed treatment. Compared with the physiological time effects, the effects of the oilseed treatments were weak. It was possible to load the adipose backfat tissue with ALA by supplementing linseed in the dry period, but the magnitude of this increase was small. Milk fat profile was not affected accordingly, although the changes found in adipose tissue post partum suggested the preferential mobilization of ALA during early lactation. Supplementing sunflower seed instead of linseed in the dry period did not elevate LA proportion in adipose tissue nor affected linoleic acid in milk. By contrast, direct transfer of LA, and especially of ALA, from feed to milk happened when sunflower seed or linseed was fed in the lactation period of the experiment. Overall this suggests that strategies aiming at changing n−3 fatty acid concentrations in milk fat composition by loading the adipose tissue of dry cows with ALA are not effective

New genomic insights into the conformation of Lipizzan horses

Conformation traits are important selection criteria in equine breeding, as they describe the exterior aspects of the horse (height, joint angles, shape). However, the genetic architecture of conformation is not well understood, as data of these traits mainly consist of subjective evaluation scores. Here, we performed genome-wide association studies on two-dimensional shape data of Lipizzan horses. Based on this data, we identified significant quantitative trait loci (QTL) associated with cresty neck on equine chromosome (ECA)16 within the MAGI1 gene, and with type, hereby differentiating heavy from light horses on ECA5 within the POU2F1 gene. Both genes were previously described to affect growth, muscling and fatty deposits in sheep, cattle and pigs. Furthermore, we pin-pointed another suggestive QTL on ECA21, near the PTGER4 gene, associated with human ankylosing spondylitis, for shape differences in the back and pelvis (roach back vs sway back). Further differences in the shape of the back and abdomen were suggestively associated with the RYR1 gene, involved in core muscle weakness in humans. Therefore, we demonstrated that horse shape space data enhance the genomic investigations of horse conformation

Soybean cyst nematode (Heterodera glycines)

Apresenta a imagem da cauda de um Heterodera glycines jovem, com final transparenteEducação Superior::Ciências Agrárias::Agronomi