Effects of sodium sulphate and potassium chloride fertilizers on the nutritive value of timothy grown on different soils

Third harvest samples from a pot experiment were analysed to study the effects of sodium (Na) (0, 200 and 400 mg dm-3 of soil in a single application as Na2SO4 . 10H2O) and potassium (K) application (0, 100 and 200 mg dm-3 applied at each harvest as KCl) on the nutritive value of timothy grown on three different soil types (clay, loam and organogenic soil). The effects of fertilization on concentrations of crude protein, neutral detergent fibre (NDF) and non-structural carbohydrates, although statistically significant, were relatively minor in absolute terms. Na applications increased and K applications decreased sulphur and phosphorus concentrations, the magnitude of which was dependent on soil type. The increase in sulphur concentration can be attributed to sulphate in Na-fertilizer. The effects of fertilizers on in vitro organic matter digestibility and the potential extent of dry matter (DM) and NDF digestibility were small. Digestion kinetic parameters estimated from fermentative gas production measured using a fully automated system were used in a rumen simulation model to estimate digestibility. Total gas volume and the rate of gas production from the rapidly digestible fraction were negatively correlated with timothy S and N concentrations. Na application had no effect, but K application increased true rumen DM digestibility, the effect being most profound on organogenic soil. The results suggest that Na application does not elicit substantial positive effects on the nutritive value of timothy which has often been reported for perennial ryegrass, but K application can improve the nutritive value of timothy grown on K deficient soil.;Tutkimuksen tavoitteena oli selvitettää natrium- ja kaliumlannoituksen vaikutusta timotein ravintoarvoon. Näytteet olivat Peltovuoren ja Yli-Hallan (1997) astiakokeesta, jossa selvitettiin Na- ja K-lannoituksen vaikutusta timotein Na, K,Ca ja Mg-pitoisuuteen ja satoon savi-, hieta- ja turvemaalla. Käytetyt ravinnemäärät olivat 0, 200 tai 400 mg Na l-1 kokeen alussa natriumsulfaattina ja 0, 100 tai 200 mg K 1-1 joka sadolle kaliumkloridina. Tähän tutkimukseen valittiin kolmannen sadon näytteet, koska niissä Na-pitoisuuden vaihtelu oli suurin (0,16-7,13 g kg-1). Vaikka timotei luetaan ns. natrofobisiin kasveihin, jotka ottavat huonosti natriumia versoihin, nousi timotein natriumpitoisuus huomattavasti. Na- ja K-lannoituksen vaikutusta timotein ravintoarvoon tutkittiin in vitro -kokein ja lisäksi määritettiin typpi, neutraalideterkenttikuitu (NDF), sokeri, rikki ja fosfori. Orgaanisen aineen in vitro -sulavuus määritettiin sellulaasimenetelmällä ja potentiaalinen kuiva-aineen ja NDF:n pötsisulavuus inkuboimalla näytettä 12 vrk nailonpussissa kahden lehmän pötsissä (in situ). Sulatuskinetiikan parametrit määritettiin mikrobikäymisen tuottaman kaasuntuotannon mittauksella ajan funktiona automaattisella mittauslaitteella, ja dynaamisen ja pötsimallin perusteella laskettiin potentiaalisesti sulavan kuiva-aineen pötsisulavuus ja kuiva-aineen todellinen pötsisulavuus. Lannoituksen vaikutus raakavalkuais-, NDF- ja sokeripitoisuuteen oli pieni. Na-lannoitus lisäsi hieman ja K-lannoitus vähensi typpipitoisuutta ja molemmat vähensivät laskennallista sokeripitoisuutta. NDF-pitoisuus nousi hieman Na-lannoituksella. Na-lannoitus lisäsi ja K-lannoitus vähensi rikki- ja fosforipitoisuutta vaikutuksen riippuessa maalajista. Na-lannoituksen vaikutukset orgaanisen aineen in vitro sulavuuteen sekä potentiaaliseen kuiva-aineen ja NDF:n pötsisulavuuteen olivat pieniä, vaikkakin tilastollisesti merkitseviä. Kokonaiskaasutuotanto ja nopeasti sulavan fraktion kaasutuotannon nopeus vähenivät, kun timotein typpi-, rikki-, kalsium-, magnesium-, fosfori- ja natriumpitoisuudet nousivat. Na-lannoituksella ei ollut vaikutusta sulatuskinetiikan parametreihin ja estimoituun potentiaalisesti sulavan kuiva-aineen pötsisulavuuteen tai kuiva-aineen todelliseen pötsisulavuuteen, kun taas K-lannoitus lisäsi hieman nopeasti sulavan fraktion kaasutuotannon nopeutta ja todellista kuiva-aineen pötsisulavuutta. Kaliumin vaikutus oli selvin turvemaalla. Maalajien välillä oli eroja kaasuntuotannon määrässä ja potentiaalisesti sulavan kuiva-aineen ja todellisessa kuiva-aineen pötsisulavuudessa, savimaa ruoho oli huonoiten ja turvemaan ruoho parhaiten sulavaa. Näiden tulosten mukaan Na-lannoituksella ei näytä olevan samanlaisia myönteistä vaikutusta timotein ravintoarvoon kuin brittiläistutkimuksissa on usein esitetty englannin raiheinällä, mutta K-lannoitus voi parantaa timotein ravintoarvoa K-puutteesta kärsivillä mailla

Responses to Grass or Red Clover Silages Cut at Two Stages of Growth in Dairy Cows

Red clover has an important role in organic farming, and also potential to reduce dependence on N fertilisers in conventional farming. This experiment compared dairy cow responses to grass and red clover silages cut at two stages of growth

NDF Digestion in Dairy Cows Fed Grass or Red Clover Silages Cut at Two Stages of Growth

Increasing demand for organic dairy products has encouraged research on red clover, as it is an important plant species in organic farming systems. The objective of this experiment was to investigate the effects of plant species and growth stage on NDF digestion in dairy cows

Energy utilization and milk fat responses to rapeseed oil when fed to lactating dairy cows receiving different dietary forage to concentrate ratio

We evaluated energy and N utilization, performance, and milk fatty acid (FA) profile using grass silage-based diets when rapeseed oil (RO) was included in high- or low-forage diets. Four multiparous Nordic Red cows averaging 101 ± 16 days in milk at the beginning of the study were randomly assigned to a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Each 21-d period consisted of a 14-d diet adaptation period and 7-d collection period. Cows were fed the following diets comprised total mixed rations based on grass silage with forage to concentrate (FC) ratio of 35:65 and 65:35 containing 0 or 50 g/kg of RO. Significant FC × RO interactions were observed for milk yield, milk protein and lactose yields, milk fat concentration, and milk proportions of trans-11 18:1, trans-10 18:1, trans-10, cis-12 18:2, and saturated FA. Feeding low-forage diet was effective in increasing milk yield compared with the high-forage diet, and the RO supplementation increased it further (P ≤ 0.01). A similar pattern was observed for the yields of milk protein and lactose. Supplementing the low-forage diet with RO reduced milk fat concentration by 19% relative to other diets without affecting milk fat yield. The proportion of N intake lost as urine decreased (P ≤ 0.05) with the RO supplementation of low-forage diet without affecting energy and N balances. Nutrient intakes were greater (P ≤ 0.01) in cows fed low-forage diet, whereas RO decreased (P < 0.05) protein, starch, and fiber intakes. Methane production, expressed as a proportion of energy intake, decreased with low-forage compared with high-forage diets and this variable declined similarly by RO supplementation of both diets (P < 0.01). The milk proportions of trans-10 18:1 and trans-10, cis-12 CLA increased (P ≤ 0.01) by RO supplementation of the low-forage but not high-forage diet. However, RO supplementation of both high- and low-forage diets increased (P < 0.01) total trans FA and decreased saturated FA proportions, even though the changes were more profound in low-forage diet (P ≤ 0.01). In addition, RO increased (P < 0.01) cis monounsaturated FA in milk for both high- and low-forage diets. Overall, the low-forage diets had lower methane emissions and RO increased partitioning of N towards milk secretion (P ≤ 0.01) without influencing energy or N balances. According to the results, RO supplementation did not compromise intake of nutrients with low-forage diets containing 150 g/kg starch, and oil could be preferentially used to improve milk production and milk fat quality accompanied by a reduction in methane energy loss

Dietary fish oil supplements depress milk fat yield and alter milk fatty acid composition in lactating cows fed grass silage-based diets

201

Prediction of nitrogen excretion from data on dairy cows fed a wide range of diets compiled in an intercontinental database: a meta-analysis

publishedVersio