Effect of concentrate supplementation level on production, health and efficiency in an organic dairy herd

The proportions of organic feed and roughage in the feed ration for organic dairy cows have to reach 100 and 60%, respectively, in 2005. The aim of this study was to elucidate the long-term effects of reducing or omitting concentrate supplementation to high genetic merit dairy cows on a basal ad libitum diet of clover-grass (silage and grazing). Three concentrate levels, N, L and L+ (38, 0 and 19% of dry matter (DM) intake, respectively) were investigated in a herd of 60 cows during 3 years. The production in group N was 6723 kg energy corrected milk (ECM) per cow year, based on an intake of 6226 kg DM of which 38% was concentrates. In group L the omission of concentrates reduced intake to 4770 kg DM, and milk production to 5090 kg ECM per cow year. Milk protein content was reduced and milk free fatty acid content was increased, and the first calving interval was significantly increased, as compared to group N. The intake in group L+ was 5226 kg DM per cow year of which 19% was concentrates. Milk production in group L+ was reduced by only 493 kg ECM per cow year as compared to group N, primarily due to a significantly improved feed conversion ratio (12%). There were no indications of health problems associated with the reduced feeding levels

Genetic potential for grain yield in spring barley varieties and variety mixtures in variable organic environments

For organic crop production, well-characterised varieties increase the possibilities for controlling diseases and weeds and compensating for deficits in nutrients. Variation in grain yield was studied in about 150 spring barley varieties and variety mixtures and 20 combinations of location, growing system and year. Choice of variety was found to be as important a factor for grain yield as other factors in the management. Some variety mixtures out yielded even the best variety in the mixture, when this was grown in pure stand. Finally, a concept for organic variety testing of spring barley was developed. This Danish project is part of a European COST Network on sustainable low-input cereal production (SUSVAR) which coordinates studies in different countries on variety mixtures, composite crosses and variety testing

Malkekvæg som dynamo for en alsidig udvikling af økologisk jordbrug

I kapitlet beskrives tre produktionssystemer, som har kørt på Den Økologiske Forsøgsstation Rugballegård gennem tre år: 1) Mælkeproduktion, 2) Svineproduktion samt 3) Kombineret produktion af svin og kvæg, hvor køerne tildeles et reduceret niveau af tilskudsfoder. Kvægbesætningen blev således delt i to hold: N på normalt foderniveau, som afspejlede det rene mælkeproduktionssystem; og L på lavt foderniveau, som afspejlede kombinationssystemet, hvor det energirige foder blev brugt til svineproduktionen. Systemerne er beskrevet gennem modelberegninger og gennem resultater fra Rugballegård. Modelberegningerne viser den højeste gennemsnitlige afgrødeproduktion på 5650 kg ts per ha i kvægsædskiftet (tilhørende malkekvæg på normalt foderniveau) mod 3250 kg ts per ha i svinesædskiftet (tilhørende produktionen af søer og slagtesvin) og 5150 kg ts per ha i det kombinerede kvæg-svinesædskifte (Malkekvæg lavt foderniveau, søer og slagtesvin). Modelberegningen viser, at forskellene primært er knyttet til sammensætningen af sædskiftet og niveauet af plantetilgængeligt kvælstof, samt at kombinationssystemet (kvæg/svin integreret) indebærer synergieffekter omkring især sædskiftet og næringsstofudnyttelsen. Den observerede produktion i systemerne afveg ikke betydende fra det forventede. Når malkekøerne blev fodret med grovfoder alene, blev intervallet mellem 1. og 2. kælvning øget og mælkens teknologiske kvalitet generelt forringet, mens der ikke var indikationer af sygdomsproblemer forbundet med det reducerede foderniveau

Calculation, normalization and perturbation of quasinormal modes in coupled cavity-waveguide systems

We show how one can use a non-local boundary condition, which is compatible with standard frequency domain methods, for numerical calculation of quasinormal modes in optical cavities coupled to waveguides. In addition, we extend the definition of the quasinormal mode norm by use of the theory of divergent series to provide a framework for modeling of optical phenomena in such coupled cavity-waveguide systems. As an example, we apply the framework to study perturbative changes in the resonance frequency and Q value of a photonic crystal cavity coupled to a defect waveguide.Comment: 4 pages, 3 figure

Introduktion - perspektiver ved 100 pct. økologisk fodring

I kapitlet skitseres den økologiske mælkeproduktion i Danmark samt de gældende og kommende rammer herfor. Desuden diskuteres perspektiverne i en økologisk mælkeproduktion baseret på 100% økologisk foder. Mælkeproduktionens omfang er gennem en kraftig vækst nået op på ca. 10% af den indvejede mælk i 2000. Markedet ser på kort sigt ud til at nærme sig en mætning, hvilket afspejler sig i en faldende merpris til producenten. Der identificeres to overordnede tendenser i udviklingen af produktionen inden for rammerne af 100% økologisk fodring: Den ene med en fastholdelse af de nuværende mål omkring produktionsniveau mv. per dyr, opnået ved en tilpasning af grovfoderkvalitet og økologisk dyrket tilskudsfoder. Den anden trend med en drejning mod en mælkeproduktion som ønskes udviklet ud fra en mere overordnet udvikling af økologisk produktion

Mælkeproduktion baseret på 100 procent økologisk dyrket foder

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Økologisk mælkeproduktion - reduceret foderniveau og strategisk anvendelse af tilskudsfoder

På den økologiske forsøgsstation Rugballegaard blev der i 1996 etableret tre produktionssystemer omfattende husdyr og sædskifte. Formålet var at belyse de overordnede bedriftsmæssige konsekvenser af økologiske produktionssystemer med kombinationer af kvæg og svin i forhold til specialiseret produktion af kvæg henholdsvis svin. Dette indlæg omhandler resulter vedrørende køerne og mælkeproduktionen. Formålet med forsøgene med malkekvægbesætningen var at undersøge malkekøernes produktion, reproduktion, sundhed og foderudnyttelse samt mælkens kvalitet, når køerne blev fodret på et reduceret niveau med grovfoder alene (primært frisk og/eller konserveret kløvergræs) eller suppleret med små mængder tilskudsfoder først i laktationen

Experiences with incomplete block designs in Denmark

Incomplete block designs were first used in the statutory variety trials in Denmark in 1979. During the last years the use of incomplete block designs in variety trials has increased and is now used both for performance trials and DUS trials in most of the trials with many entries. The need for incomplete block designs has increased as the number of varieties in many crops has increased. Incomplete block designs are also used in a few other types of designs such as trials with different pesticides. Most of the incomplete block designs have been Alpha-designs. Examples of designs and the efficiency of such designs were presented together with a discussion of the most important benefits and drawbacks of using such designs

Grobund for innovation, vækst og troværdighed

Økologiske landmænd og fødevarevirksomheder har brug for forskning og udvikling, der både øger produktiviteten og samtidig reducerer miljø- og klimabelastning, men også sikrer biodiversiteten i mark og landskab og en fortsat høj dyrevelfærd

Catch Crops in Organic Farming Systems without Livestock Husbandry - Simulations with the DAISY model

This paper presents simulations of the soil-plant-atmosphere model DAISY based on an organic crop rotation with incorporation of different catch crops following pea as a leguminous cash crop. Special emphasise was put on the simulation of N-mineralisation/-immobilisation and of soil microbial biomass N. The DAISY model was able to simulate soil mineral N and soil microbial biomass N after soil incorporation of catch crop plant residues to some extend. Several processes need further attention and may be integrated into the DAISY model: (1) soil tillage induced mobilisation of organic material including considerable amounts of organic N, (2) winter killing of sensitive plant species and varieties, (3) decomposition of plant residues at the soil surface as occurring after winter killing, (4) decomposition of easily decomposable plant residues at low temperatures, (5) soil microbial residues as an organic pool temporarily protected against turnover. Furthermore, reliable criteria for the subdivision of green plant residues into an easily decomposable pool and a more recalcitrant pool have to be developed