FORUT-Nutrient supply and productivity in organic forage and milk production - improved forage production based on local resources

Finished Last updated: 16.02.2017
End: sep 2015
Start: jan 2011

Organic milk production has become more intensive, which has led to increased focus on forage quality. The primary growth (PG) is harvested at an earlier stage of development with the consequence that more than half of the total yearly yield is from the regrowth (RG). The RG contains high proportion of clover. Thus, the RG forage has likely high crude protein content, while the PG forage has high energy value but low protein content. The use of fish meal as feed is now prohibited and alternative feed protein sources are expensive. The value of on-farm grown forage is therefore becoming even higher. The project aims to bring to light knowledge that makes dairy farmers better prepared to produce forage in high quantities and qualities as allowed by local climate and resources, adapt forage and milk production better to these constraints, and to assess the economics, resource use and environmental impacts linked to forage production and feed rations with high forage quality. Specifically, the research conducted in the project seeks to answer the following questions: - When ought the RG to be harvested? - Are early red clover varieties better suited than late ones to sustain high yields and even out differences in forage yield and quality between cuts in intensive harvesting regimes? - Will other grasses than timothy and meadow fescue perform better as companion species to red clover under intensive harvesting regimes? Are grass species and variety mixtures that have less synchronous generative development to be chosen? - How should forage with high clover proportion be preserved in order to attain high forage protein quality? - Is it possible to utilize that PG and RG silages have different quality by mixing them in certain proportions at feeding? - What is won and what is lost in economic terms when forage production is intensified? - Will a mixing of PG and RG silages at feeding reduce methane emission and nitrogen loss in the cow and from the slurry storage

Status Concluded
Start - end date 01.01.2011 - 01.09.2015
Project manager Håvard Steinshamn
Total budget 12000000

Publications in the project

Abstract

Råproteininnhaldet var høgare og proteinet var meir stabilt under konservering i raudkløverdominert gjenvekst enn i grasdominert vårvekst. Likevel vart proteinverdien lågare i gjenvekstsurfôret, spesielt dersom ein la til rette for sterk gjæring. Tilsetjing av maursyrehaldige ensileringsmiddel for å hemme nedbryting av lettomsetjelege karbohydrat vil vere eit godt tiltak for god proteinkonservering. både i vårvekst og gjenvekst.

Abstract

Lønnsemd, uttrykt som dekningsbidrag per årsku, auka med årsavdråtten (kg EKM/årsku) hos økologiske mjølkeprodusentar i Trøndelag. Det var ingen samanheng mellom kraftfôrnivå (FEm/årsku) og lønnsemd, men lønnsemda auka med aukande grovfôropptak

Abstract

A meta-analysis based on experiments in organically cultivated grasslands in Norway was conducted to quantify the effects of management factors on herbage yield and feed quality. A dataset was collected that included 496 treatment means from experiments in five studies carried out at eight locations with the latitude range of 58.8 to 69.6 N between 1993 and 2010. We tested the effect of harvesting system (two vs. Three cuts annually), plant developmental stage at the first cut, growth period (temperature sum) and the herbage clover proportion. Plant maturity at the first cut and herbage clover proportion explained to a large extent herbage yield and quality of the first cut and annual yield. The timing of the first cut influenced also the yield and herbage quality of the second cut. The analysis confirmed the importance of legumes performance for herbage yield and quality from grasslands in organic production. Estimated annual herbage DM yield harvested at standardized plant development stage and at average clover proportion was 9%higher in the two—compared to the three-cut system. The crude protein concentration and in vitro dry matter digestibility was 17 and 3 % higher and the NDF concentration 7 % lower in the annual herbage from the three-cut than from the twocut system, respectively. The empirical equations developed in this study may be applied to explore different options for grassland management as basis for ration and production planning and in scenario analysis of economic performance of individual and model farms. The equations do also reveal in numeric terms the tradeoffs in management practice between high yields, yield digestibility, NDF and crude protein content in organic forage production relying on red clover N2 fixation as the engine in the system.

To document

Abstract

Clover proportions, and thereby chemical composition of herbage, differ between primary growth (PG) and regrowth (RG) in organic managed grass-clover fields. The characteristics of PG and RG silages suggest different supplementary feeding strategies to sustain an efficient milk production in dairy cows. Silage made of the RG generally offers more crude protein (CP) in the diet than silage made of the PG because of an increasing proportion of clover later in the season. Additionally, grass and clover have different amino acid (AA) profiles. His has been suggested to be the first limiting AA in grass silage, while Met has been suggested to be the primarily limiting AA in red clover silage. Eight rumen cannulated Norwegian Red cows were used in two replicated 4 × 4 Latin squares with 21-days periods. Organic PG and RG silages were fed ad libitum in four diets with RG replacing PG silage in ratios of 0, 0.33, 0.67 and 1 on dry matter (DM) basis. Changing RG silage proportions from 0 to 1 increased daily CP intake from 2.90 to 3.08 kg and rumen NH3-concentrations from 4.9 to 8.4 mmol/L, but did not promote a better protein supply. Neither total ruminal outflow of AA nor the AA profile in the small intestine differed between dietary treatments. Met and His were probably the most limiting AA for a higher milk production. Limitations by His may be more related to diets based on PG, while production by cows fed diets based on more RG herbage were more likely limited by Met.

To document

Abstract

Effects of wilting rate and fermentation stimulators and inhibitors on protein characteristics of forages typ- ical for organic production were assessed using tradi- tional analytical methods and a gas production in vitro assay. The hypotheses were that the proportion of the crude protein (CP) fraction that was soluble would be lowest, and the protein feed value highest, under rapid wilting and restricted fermentation. The solubil- ity of the CP fraction varied according to treatments and between a first and a second cut, with moderate and high content of clover respectively. It was, how- ever, of minor importance for the protein value, both calculated as amino acids absorbed in the small intes- tine (AAT 20 ) and estimated as effective utilizable crude protein (uCP 04 ) by the in vitro assay. In ensiled her- bage, AAT 20 was highest in rapidly wilted and restrict- edly fermented silages made from a first cut dominated by highly digestible grasses. Silages from the second cut dominated by red clover were far lower in AAT 20 . The in vitro assay did not separate silages according to herbage composition or wilting rate, but ranked restrictedly fermented above extensively fer- mented with regard to protein supply. The assay might still have caught the characteristics that determine the true protein value in vivo.