Effect of forage legumes on feed intake, milk production and milk quality – a review

Literature data from experiments with lactating dairy cows offered silage-based diets was reviewed to evaluate the effects of the grassland legume species Trifolium repens (WC, white clover), Trifolium pratense (RC, red clover) and Medicago sativa (M, lucerne) on feed intake, milk production and milk quality. Seven data sets were created to compare grass silage (G) with grassland legumes in general(L), G with RC, G with WC, G with M, RC with WC, RC with M and different silage proportions of RC. Daily dry matter intake and milk yield were on average 1.6 and 1.6 kg, respectively, higher and milk fat content 1.2 g/kg milk lower on L than on G based diets. Similar differences were found when G was compared with RC or WC diets. Cows offered WC yielded 1.1 kg/d more milk than RC, and milk produced on WC and M contained 0.7 g more protein per kg than milk from RC diets. Increasing the silage diet RC proportion from 0.5 to 1.0 also decreased the milk protein content by 0.8 g/kg milk. RC increased the level of poly-unsaturated fatty acids, particularly C18:3n-3, and isoflavones, particularly equol, in milk. Effects are discussed in relation to plant cell wall characteristics, plant chemical constituents and changes in rumen digestion to explain the origin of the differences in intake, milk yield and milk compositio

The unique properties of red clover in the diet of ruminants

Grassland legumes are essential in organic ruminant livestock production due to their ability to fix atmospheric nitrogen (N), providing high yields of high feeding value without N fertilization. White clover (Trifolium repens L.) and red clover (Trifolium pratense L.) are the most important legumes of temperate grasslands with white clover as the most widely used. New research has reviled new properties of red clover that may affect animal performance and product quality significantly. Red clover containing diets have increased the production of milk and meat (compared with grasses) and the content of beneficial fatty acids in milk and meat (compared with grasses and other legumes), improved the efficiency of feed N utilization (compared with Medicago sativa L.), and increased the milk content of isoflavones (compared with grass and white clover). Red clover contains high levels of the enzyme polyphenol oxidase that might reduce the extent of lipolysis and proteolysis. The paper presents a review on resent results from own and others’ research on the use of red clover in the diet of ruminants and the likely mechanisms by which red clover affects production and product qualit

Forage botanical and chemical composition on dairy farms with different grassland systems and production systems

Thirty-two dairy farms in Middle-Norway with different grassland systems (short-term (7 years) grassland (L)) and different production systems (organic (O) or conventional (C)) were compared in a field study in 2007. In a principal component analysis on variables including farm details, botanical composition and chemical forage composition, the farms were separated into organic and conventional farms with the exception of one farm. Amongst the organic farms most SO farms were distinguished from LO farms. Concentration of forage crude protein was positively correlated with proportion of grass. Concentration of non-fibrous carbohydrates, in vitro digestibility and net energy lactation was positively correlated with proportion of legumes. Species diversity and cutting time at first cut was positively correlated with proportion of non-legume herb

Workshop on quality and nutrition value of organic milk and meat

The workshop was arranged at the Institute of Genetics and Animal Breeding PAS in Jastrzębiec (IGAB), Poland, 19.-20. November 2009. The aim of the workshop was to encourage cooperation between Norwegian and Polish scientists specialized in organic animal breeding and organic milk and meat production. The organic market in Europe is growing annually from 2 to 15% depending on a country. Establishing scientific contacts with Norwegian researchers will positively influence the development of Polish organic scientific sector, which will transfer further the obtained knowledge and experience direct to the farmers. The workshop enabled Norwegian scientists to establish contacts with scientists from Poland and from other Central-European countries. The agenda of the meeting took into account the discussion on challenges and scientific ideas together with German, Austrian and Czech scientists. The workshop allowed presentation of contemporary organic breeding and production strategies for optimizing production methods in achieving high quality of organic milk and meat with high nutritive value for consumer. The presentations are available at the website: http://www.ighz.edu.pl/?p0=4&p1=32&p2=134&p3=135 During the second day of the workshop, the participants worked together and made outlines of future cooperation based on the presentations given on the first day. The workshop was funded by the Polish-Norweagian Research Fund (PNRF 284–A II– 2/08

IMPLICATIONS OF HARVESTING STRATEGIES ON POPULATION AND PROFITABILITY IN FISHERIES

The effects of different harvesting strategies on the mean and variation in size of the fish stock and net revenues are investigated. The strategies analyzed are constant catch, constant effort, and constant escapement. A Gordon-Schaefer model affected by cyclical disturbances and stochastic disturbances is applied. Factors explaining the differences between the strategies are the length of the recruitment cycles and the presence of stochasticity. With short recruitment cycles the constant catch strategy somewhat surprisingly produces least variation and highest mean with respect to stock size and net revenue, while constant escapement produces most variation and lowest mean. With longer recruitment cycles or pure stochasticity, constant escapement produces highest average stock size and net revenue as well as lowest variation in the stock size, but not in the net revenue. Constant effort is in most cases ranked between the other two strategies.Resource /Energy Economics and Policy,

Produksjon og utnytting av gjenvekst ved høge avdråttsnivå

Kyr med høg avdrått må få energirikt grovfôr frå eng som er tidleg og hyppig slått, og der gjenvekstar utgjer ein stor del av årsavlinga. Mellom vårvekst og gjenvekst vil det vere variasjon i proteininnhald og fiberkvalitet. Det trengst meir kunnskap om korleis ein kan balansere dei ulike kvalitetane i ei målretta fôring

High Nitrogen Costs of Dairy Production in Europe: Worsened by Intensification

Intensification of agriculture has been proposed as one way of minimizing emissions per unit of product, apparently legitimizing the ongoing structural changes in agriculture. We have investigated the relationship between the farming intensity and the nitrogen (N) dissipation by calculating the overall N emission factor (E: total N surplus per unit of N in the produce) from several studies of dairy farms, covering a wide range of environments and production intensities. Fundamental steps were 1) the distinction between trophic levels, mineral, plant and animal N; and 2) the inclusion of N losses related to bought feed. The results show that E increases significantly with the production intensity of the dairy farm. The tradition for separate optimization of the animal and crop sectors may be a reason. We suggest that the N pollution can be mitigated by more extensive farming, both by re-coupling crop and animal production side by side, and by keeping land under cultivation when production is reduced

Grovfôrutnytting hos kjøttfe - er det forskjell

Dei totale fôrkostnadane utgjer om lag 80% og grovfôrkostnadane 60% av dei variable kostnadane i sjølvrekrutterande storkjøttproduksjonen (Nortura). Det kan derfor være mye å hente økonomisk dersom det er mulig å betre effektiviteten i fôrutnyttinga

OPTIMAL STEADY STATES AND THE EFFECTS OF DISCOUNTING

A simple expression for finding and characterizing the optimal steady state of a general dynamic optimization problem is derived. This expression is easy to interpret and easy to apply for various purposes as, for example, to analytically investigate the effect of the discount rate upon optimal steady state stock levels. It is shown that an increase in the discount rate may result in higher optimal stock levels even in the one-dimensional (single species) case in nonlinear models. An important result is that if demand is inelastic at the optimal steady state, a higher discount rate will unequivocally imply higher standing stock(s). Increasing marginal cost of harvest will further strengthen this result. In the multidimensional case it is demonstrated that an increased discount rate may result in higher optimal stock levels for all stocks included in the model.Research Methods/ Statistical Methods,

Influence of clover species in mixtures with grasses on fatty acid composition of mixtures

White clover (WC, Trifolium repens L.) or red clover (RC, Trifolium pratense L.) was grown in mixture with grasses. Samples of the mixtures and pure clovers were taken during three cuts, and the fatty acids (FA) compositions were determined. The clover species had no significant effect on the individual FA contents of the leys (g kg-1 dry matter (DM)), nor on the total FA content. Pure clovers had lower content of all individual FA (8.2 vs. 12.4 g kg-1 DM) than mixtures; the contents of all FA decreased with increasing percentage of clover in the mixture, but the decrease was weaker for C18:3n-3 than for the other FA. Although pure WC and RC had similar FA contents, the relative proportions (percentage of total FA content) of C16:0 and C18:3n-3 differed; RC had a higher proportion of C18:3n-3 and a lower proportion of C16:0. These results are partly in contradiction with previously reported