Browsing by master's degree program "Master 's Programme in Agricultural Sciences"

This study investigated the frost hardiness of cranberry (Vaccinium macrocarpon Ait.) in four cultivars (’Early Black’, ’Howes’, ’Pilgrim’ and ’Stevens’), focusing especially on the frost hardiness of roots in soilless cultivation. Plants for the study were forced in a greenhouse from cuttings of mother plants. The cuttings were rooted in pots diameter of 10 cm x 10 cm in forest peat. Plants were set to grow in the high tunnel over the growing season. Two experiments were conducted during winter 2020–2021. In the experiments, whole plants with pots were exposed to freezing treatments in a controlled freeze chamber at the temperatures of -10, -15, -20 and -30 °C. Control plants were exposed to cooling at +2 °C for an equal time. In the first experiment, plants were exposed to freezing treatment in November straight from the high tunnel. The second experiment took place in January, and plants were overwintered outside until the experiment. After the freezing treatment one upright in each plant was cut, set in a glass tube containing distilled water, and forced in the greenhouse for 14 days. The vitality of the buds, leafs and stems in the cuttings was observed with a stereomicroscope. After the freezing treatment the vegetative growth of the plants grown in pots was cut off exluding the main shoot, which was cut 5 cm above the soil surface. Thereafter plants were forced in the greenhouse over 10 weeks (the light period of 18/6 h, temperature +20 °C). The vitality of the roots was determined by measuring the amount of the new vegetative growth. All the plants tolerated -10 ° C freeze in November and -15 ° C in January, respectively without injury. Some new growth was observed in plants exposed to freezing treatments of -5 ° C below the temperature mentioned above, but frost damage occurred, and the re-growth was decreased compared to control plants. Cultivar Stevens was more tolerant than the others in both experiments conducted. It maintained its growth potential after -15 °C freezing treatment in November, and -20 °C in January respectively. Frost hardiness (LT50) of buds ranged in November from -19 °C to -27 °C. In January ’Stevens’ buds had the highest frost hardiness (LT50 =-36 °C) and ’Pilgrim’ buds had the lowest (LT50 =-27 °C). The environmental conditions throughout the whole growing season may affect frost hardiness, thus, this experiment should be repeated for verifying the results obtained. Also the potential impact of dormancy in the experiment conducted in November cannot be ignored.

The objective of the thesis is to review and characterize (i) typical agroforestry systems in the temperate zone, (ii) levels of soil organic carbon (SOC) in agroforestry and control plots, and (iii) identify the conditions under which agroforestry farming is most likely to enhance SOC. A meta-analysis was conducted to investigate the impact of agroforestry farming systems on SOC stocks at soil depths of 0 – 20, 0 – 40 and 0 – 100 cm. Data was collected from 15 published studies and all sites are located in temperate climates. Studies had to report at least measurements on SOC concentration or stock for an agroforestry plot and a control plot (arable land, grassland, forest). Investigated treatment variables were soil depth, agroforestry system type, soil type, tree species and age. The results have shown significantly higher SOC stocks under agroforestry in comparison to controls in all three soil depth datasets. The largest amount of SOC in agroforestry was found in the first 20 cm of topsoil and at a soil depth of 60 – 100 cm. There were no significant differences found between alley cropping, silvopasture and shelterbelt systems. The most popular tree species in temperate agroforestry were Populus spp., M.domestica, Juglans regia and Picea. But no significant differences in C sequestration could be observed between tree species across all datasets. The assumption that systems with older trees have higher stocks of SOC could not be confirmed. Most common soil types of temperate agroforestry systems were Luvisol, Fluvisol and Chernozem. The meta-analysis did not verify results of other studies, which have shown that clay contents in the soil promote C sequestration. The wide variability and diversity of agroforestry systems has shown to be problematic in conducting a meta-analysis, indicated by a high heterogeneity. Furthermore, different types of study designs, lack of standardized sampling procedures and explanatory variables may have influenced the results. However, the study showed that agroforestry can be a promising carbon dioxide (CO2) mitigation option, also for the temperate climate zone.

In order to achieve carbon neutrality and slow down climate change, it is necessary not only to curb greenhouse gas emissions but also to remove carbon from the atmosphere. In agricultural sector, adding biochars to soils has proven to be one of the most effective methods to sequester carbon. Using biochars in urban planting soils could be simple and effective way to create carbon sinks also in urban environment. Wood based biochars are already available in the market and their viability as soil amendment is supported by an extensive body of research. Despite large evidence from agricultural and greenhouse sectors, research focused on biochars in planting soils for urban trees is scarce. To assess and demonstrate viability of biochars as component of urban planting soils, an experiment was established in 2019-2020 in Hyväntoivonpuisto-park in Helsinki. The experiment consists of four tree species and nine different planting soils, seven of which include biochars. Three of the planting soils were structural soils installed below a sealed surface. Tree growth in planting soils was followed and biomass accumulation was estimated with allometric equations. Planting soil nutrient composition was analysed at the time of soil application and nine months later after first growing season. Pyrogenic carbon fractions were analysed by BPCA analysis. Planting soil physical and hydrological properties were analysed by water retention curves with pF range of 0 – 4.2. After two growing seasons, biochars had increased tree growth in two planting soils compared to the control while in other planting soils with biochar, the growth was similar to control. In structural soils biochars had improved growth, but there were no statistically significant pairwise differences between treatments. Biochars increased the macroporosity of planting soils, indicating they could improve aeration and water conductivity in planting soils. Effects to total porosity and water retention capacity were mixed, but highest total porosity and water retention capacity was observed in planting soil with the highest amount of biochar. Planting soil nutrient composition varied a lot due to different raw materials, limiting the possibilities of making mechanistic analysis of effects of biochars. These results indicate that biochars are viable and safe constituent for planting soils which may increase tree growth by improving soil physical properties and improve carbon sinks in urban infrastructure.

Securing food production is an important objective, especially as climate change affects production conditions. Good crop yields are part of food security, but disease pressure and abiotic stress factors limit yield potential. Chemical plant protection products, which have traditionally been used in plant protection, pose an environmental risk and efforts are therefore being made to reduce their use and replace them with, for example, biological plant protection products. Biostimulants aim to improve crop yields. The aim of this study was to determine whether biomass products produced in different ways have antifungal or biostimulant effects. Three different concentrations of biomass products were used in the experiments. In screening experiments, the antifungal activity of biomass products was investigated in petri dish experiments to test their effect on the growth of two plant pathogenic fungi, Fusarium graminearum and Rhizoctonia solani. The biostimulant effect was investigated by a germination experiment on barley. In the following experiments, the effect of biomass products was investigated in the model organism Physcomitrium patens moss. P. patens was inoculated with two fungal isolates, Rhizoctonia solani and Sclerotinia sclerotiorum, and treated with biomass products. Biostimulant properties were observed on uninoculated P. patens. In addition, the study examined, whether the gene expressions of P. patens change due to the influence of biomass products using RT-qPCR. In Petri dish experiments, biomass products inhibited the growth of both F. graminearum and R. solani fungi. The highest concentration tested was most effective against fungi. The lowest biomass product concentration tested was most effective in inducing barley growth. Biomass product in combination with S. sclerotiorum infection caused death of P. patens, but the combined effect with R. solani infection induced P. patens growth. Gene expression of the three transcription factors tested and one defense gene changed by the interaction of biomass products and R. solani infection. Based on the results obtained in the study, biomass products have potential to be used in fungal disease control. The use of biomass products as biostimulants also seems promising. A lot of further research on biomass products is needed to understand their effects on different crops and pathogenic fungi.

Väestönkasvu lisää tarvetta öljykasvien tuotannolle ihmisravinnoksi ja biopolttoaineeksi. Öljynpuristamisesta saatavat sivutuotteet, kuten rouheet ja puristeet sisältävät hyvälaatuista valkuaista eläinten ruokintaan. Camelina (Camelina sativa) ja hamppu (Cannabis sativa) ovat potentiaalisia vaihtoehtoja nautojen valkuaisruokinnassa. Tutkimuksen tavoitteena oli selvittää camelina- ja hamppupuristeen vaikutusta in vitro pötsikäymiseen eri karkearehukäsittelyillä. Karkearehuina käytettiin lämpökuivattua nurmi-, puna-apila- ja maissisäilörehua ja väkirehuna ohraa. Kontrollina toimivat rypsipuriste ja käsittelyt, jotka eivät sisältäneet täydennysvalkuaisrehua eli koostuivat ainoastaan karkearehusta ja ohrasta. Kaikkien käsittelyiden karkearehu:väkirehusuhde oli 1:1 kuiva-aineessa. Valkuaislisättömien käsittelyiden raakavalkuaispitoisuudet vaihtelivat 95–140 g/kg ka välillä riippuen käytetyn karkearehun raakavalkuaispitoisuudesta. Valkuaiskäsittelyissä raakavalkuaispitoisuudeksi tuli 170 g/kg ka. Inkubaatiopulloihin punnittiin rehuja yhteensä 3,5 g ka. Käsittelyitä oli 12 kpl ja lisäksi jokaisessa ajossa oli 2 kpl blancoja, joihin ei punnittu rehuja. Ajoja tehtiin neljä. Jokainen ajo kesti 30 h ja näytteitä otettiin 1, 4, 8, 12, 24 ja 30 h kuluttua inkubaation aloituksesta. Näytteistä määritettiin haihtuvat rasvahapot (VFA), ammoniumtyppi ja pH. Analyysituloksista laskettiin haihtuvien rasvahappojen moolisuhteet. Tutkittavista rehuista analysoitiin lisäksi sekundäärinen kuiva-aine, tuhka, tuhkaton neutraalidetergenttikuitu (NDF), raakavalkuainen ja kokonaisrasva. Valkuaisrehuista analysoitiin typpifraktiot (A, B1, B2, B3 ja C). Rypsi-, camelina- ja hamppupuristeen raakavalkuaispitoisuudet olivat 332, 367 ja 286 g/kg ka vastaavasti. Hypoteesin vastaisesti valkuaisrehun lisääminen ei lisännyt VFA:n kokonaismäärää ja ammoniumtypen muodostusta. Hypoteesin mukaisesti valkuaisrehun lähde vaikutti pötsikäymisen voimakkuuteen. Camelina- ja rypsipuristetta sisältävät käsittelyt vastasivat toisiaan VFA:n kokonaismäärässä (P>0,05) hypoteesin mukaisesti. Camelina lisäsi kuitenkin propionihapon kokonaismäärää (P<0,05) ja mooliosuutta (P<0,01) verrattuna rypsiin sekä pienensi voihapon mooliosuutta verrattuna rypsiin (P<0,01). Hamppupuristeella VFA:n kokonaismäärä oli pienempi kuin camelinapuristeella (P<0,05) ja suuntaa antavasti pienempi kuin rypsipuristeella (P=0,063). Hamppupuriste vähensi propionihapon kokonaismäärää ja lisäsi etikkahapon mooliosuutta verrattuna rypsiin (P<0,001 ja P<0,01, vastaavasti) ja camelinaan (P<0,001 ja P<0,01, vastaavasti). Karkearehun lähde vaikutti VFA:n kokonaismääriin ja moolisuhteisiin. Puna-apilasäilörehua sisältävissä käsittelyissä VFA:n kokonaismäärät olivat suuremmat kuin maissisäilörehua sisältävissä käsittelyissä (P<0,05). Puna-apilasäilörehukäsittely lisäsi etikkahapon ja propionihapon kokonaismääriä verrattuna nurmisäilörehukäsittelyihin (P<0,05 ja P<0,01 vastaavasti) ja maissisäilörehukäsittelyihin (P<0,01 ja P<0,05, vastaavasti). Tulosten perusteella camelinapuristeen raakavalkuaispitoisuus oli rypsiä suurempi ja näiden VFA:n kokonaismäärät ja typpifraktiot vastasivat toisiaan. Camelina voisi siis vastata rypsiä nautojen valkuaisruokinnassa, mutta hampun valkuaisarvo on mahdollisesti näitä alhaisempi VFA:n kokonaismäärän ja moolisuhteiden perusteella. Hamppupuristeen suurempi NDF-kuidun määrä voisi selittää camelina- ja rypsipuristekäsittelyitä suuremman etikkahapon mooliosuuden. Karkearehun lähde vaikutti pötsikäymiseen ja puna-apila lisäsi VFA:n kokonaismäärää verrattuna nurmi- ja maissisäilörehuun, jolla voi olla positiivisia vaikutuksia energiansaantiin ja maitotuotokseen.

Nykyään kuluttajat ovat entistä kiinnostuneempia elintarvikkeiden laadusta ja niiden terveellisyydestä. Eläinperäisten tuotteiden koostumukseen voidaan vaikuttaa eläimille syötettävän rehun kautta. Suomessa täydennysvalkuaisrehun omavaraisuusaste on heikko, 20,9 % vuonna 2021, joten siihen kaivataan uusia vaihtoehtoja rypsin ja rapsin rinnalle. Tässä tutkielmassa tutkittiin camelinan ja hampun soveltuvuutta kotieläinten ruokintaan täydennysvalkuaisrehuna, koska niiden siemenet sisältävät runsaasti valkuaista ja rasvaa. Aineiston siemennäytteet kerättiin camelinaa (n=5) ja hamppua (n=20) viljelyttäviltä yrityksiltä (Janakkalan piensiemen ja TransFarm), näytteet olivat kasvukaudelta 2021. Hampusta analysoitavat siemennäytteet valittiin siten, että niissä on mukana sekä suuren sadon (>600 kg/ha) että pienen sadon (<400 kg/ha) näytteitä ja että ne ovat maantieteellisesti mahdollisimman edustavia. Näytteistä analysoitiin peruskoostumus; kuiva-aine, kokonaisrasva, raakavalkuainen, tuhka ja neutraalidetergenttikuitu (NDF). Lisäksi haitta-aineista analysoitiin glukosinolaatit camelinasta ja trypsiini-inhibiittorit camelinasta ja hampusta. Hampusta kerättiin viljelytietoja kyselyllä, jonka TransFarm oy toteutti sopimusviljelijöilleen kasvukausilla 2021 (n= 61 kpl) ja 2022 (n=59 kpl), vastauksia saatiin yhteensä 120 kpl. Tilastollisia yhteyksiä hampusta selvitettiin SAS-tilasto ohjelmalla ristiintaulukoinnin, varianssianalyysin ja korrelaatioanalyysin avulla. Tilastoanalyyseja ei tehty camelinan koostumuksesta havaintojen pienestä määrästä johtuen. Tulosten mukaan hampun satotasoon vaikuttivat kasvuston korkeus, puintikosteus, taimettuneiden yksilöiden määrä ja tuotantomuoto. Mitä korkeampi kasvusto (P<0,001) ja mitä suurempi puintikosteus (P<0,05), sitä suurempi osuus havainnoista sijoittui suurimpaan satotasoluokkaan (>600 kg/ha). Lisäksi suuntaa-antavasti (P<0,10) taimettuneiden yksilöiden määrän (kpl/m2 ) lisääntyessä suurempi osuus havainnoista sijoittui suurimpaan satotasoluokkaan. Hypoteesin vastaisesti typpilannoitustasolla ja maan fosforiluokalla ei havaittu olevan yhteyttä hampun satotasoon (P>0,10). Luomutuotannossa suurempi osuus havainnoista sijoittui pienimpään satotasoluokkaan (P<0,05) ja suuntaa-antavasti matalampaan kasvuston korkeusluokkaan (P<0,10) kuin tavanomaisessa tuotannossa. Ristiintaulukoinnissa (n=120) ei havaittu yhteyttä tuotantomuodon ja kasvuajan välillä, varianssianalyysissä (n=20) luomutuotannossa oli lyhyempi kasvuaika kuin tavanomaisessa tuotannossa (P<0,05) Kokonaisrasvapitoisuudet olivat camelinan siemenissä 375– 410 g/kg ka, hampun siemenissä rasvapitoisuudet olivat suurempia pienemmän satotason siemenissä, kuin suuremman satotason siemenissä, (P<0,001; 365 vs. 339 g/kg ka). Raakavalkuaispitoisuus camelinan siemenellä oli 267–303 g/kg ka ja hampun siemenellä 275–277 g/kg ka, satotaso ei vaikuttanut hampun raakavalkuaispitoisuuteen (P>0,10). Tuhkapitoisuus oli camelinalla 33,7-40,5 g/kg ka ja hampun siemenellä 56,8-59,3 g/kg ka, satotaso vaikutti suuntaa antavasti hampun tuhkapitoisuuteen (P<0,10) ollen korkeampi pienemmän satotason siemenissä verrattuna suuremman sadon siemeniin (59,3 vs. 56,8 g/kg ka). Camelinan siementen glukosinolaattipitoisuudet olivat 15,7–26,3 mmol/kg ka ja trypsiini-inhibiittoriaktiivisuus (TIA) 15,0- 22,2 mg ka. Hamppunäytteiden TIA-pitoisuudet olivat suuntaa-antavasti korkeammat suuremman sadon siemenissä verrattuna pienemmän sadon siemeniin (P<0,10; 4,29 vs. 4,07 TIA/ mg ka). Tulosten perusteella camelinan ja hampun siementen koostumuksessa esiintyy vaihtelua, johon hampun osalta vaikuttaa satotaso. Hampun satotasoon voidaan vaikuttaa viljelykäytännöin. Camelina ja hamppu soveltuvat siemenen koostumuksen, glukosinolaattipitoisuuden ja trypsiini inhibiittoriaktiivisuuden perusteella täydennysvalkuaisrehuna osaksi kotieläinten ruokintaa

During the last 50 years, agriculture in Finland has become more intensive, open semi-natural farmland habitats have disappeared and the number of animals and plants has been declining. Nectar plants are beneficial resources in agroecosystems. They support crop pollinators, and natural enemies of pests and other species dependent on nectar. Nectar plants can also be indicators of biodiversity. Nectar source plants in field margins provide nectar (and pollen) over the growing season. Various plants benefit from different margins, and their frequency and distribution can be connected with the landscape structure and latitude. This study examined the distribution of nectar plants in field margins of farmland in Southern Finland and determined what plant species provide nectar and at what time of the season. The objectives of the research were to describe the species composition of nectar plant communities in Southern Finland, and hence the biodiversity of plants, and to study the distribution of nectar source plants in the most common margin types. The data were obtained from the Luonto-Mytvas Project research programme “Significance of the Finnish agri-environment support scheme for biodiversity and landscape (Nature MYTVAS)” in 2000-2006. In order to find out what plants have good nectar (pollen) availability literature sources and bee calendars were used. The results shows that the majority of 50 most frequent plants species included in the analysis have value as nectar and pollen sources available for pollinators. There were four different functional groups (f) of plants in the research, depending on their nectar availabilities. The frequent plants in the field margins are available as nectar/pollen sources to pollinators, from April until September-October. There are only few species dependent on margin type in their occurrence. Frequencies of most of the species from all the four groups varied, however, between field-to-field and field-to-road margins.

Nutrients get deposited in lake sediment from agricultural areas and other anthropogenic activities resulting in internal P loading and eutrophication. On the other hand, the situation with P rock (non renewable resource) used for production of mineral fertilizer is alarming that result in the depletion of P rock and increase P fertilizers price. The issue can be minimized by sediment removal and recycling nutrients from sediment for crop production. The existing results on sediment P availability for crops showed contradictory results and suggested that sediment P bioavailability for the crop is influenced by sediment iron to phosphorus mass ratio. However, comprehensive studies confirming their relationship are currently lacking. Hence, the study aims to determine the potential of sediment as fertilizers for crop (ryegrass) from several eutrophic lakes (in Finland and Estonia). The aim is to identify the effect of different lake sediments on ryegrass aboveground biomass and nutrient uptake. The study was conducted on greenhouse for around 6 months. Randomised complete block design was used for the experiment. The experimental treatments include sand with six different lake sediments: Peipsi, Lämmijärv, Kutajärvi, Kymijärvi, Matjärvi and Enonselkä basin of Vesijärvi, mineral fertilizer (positive) and without P fertilizer (negative) control. The biomass (yield) and nutrient uptake by the plants were measured and then analyzed for nutrient content. Significant effect of lake sediment was observed on ryegrass yield and P uptake. The significantly higher yield was observed for Lake Peipsi sediment treatment than in both controls. The ryegrass dry matter yield was greater in sediment treatments than negative control. Also, ryegrass yield was found to be greater in some sediment treatments than positive control. The concentration of nutrients (sulphur, calcium, magnesium, and potassium) was sufficient in ryegrass plant in all lake sediment treatments. The P uptake from Enonselkä sediment treatment was the highest whereas from Kutajärvi sediment treatment was the lowest. The P uptake was the highest (16.3 kg ha-1) in Enonselkä sediment treatment with the lowest Fe:P ratio of 12. Moreover, the result suggests that Fe:P mass ratio is one of the factors/sediment properties that determine P availability to the crops. However, other sediment properties may also affect P availability in the plants as organic P fraction was also used as an additional P source in some cases. The sediment increased C content and organic matter content compared to controls which improved ryegrass growth in sediment treatments. The increase in nutrient uptake and biomass in lake sediment treatments showed that lake sediment can be potential alternatives for fertilizers in nutrient deficient soil.

Harvesting pure red clover as silage gives new possibilities to optimize forage feeding of cattle for different animal groups and compromises between plants during cultivating, harvesting, wilting or ensiling are not needed as with mixed swards. This pilot scale preservation study was made as part of Opti-Palko project and the aim was to resolve best practices to ensile pure red clover. Si-lages was made from second harvest pure stands of Selma red-clover and Nuutti timothy and 50% / 50% mixture of those. The crops were ensiled immediately after harvesting and after wilting in dryer. There were five additive treatments comprising of three different acid-based products (formic acid based AIV 2 Plus Na (AIV2), AIV Via (VIA) which includes high proportion of propionic acid, un-corrosive acid mixture buffered with sodium formate (AIVB)) and heterofermentative lactic acid bacteria inoculant Josilac Combi (LAB) and control (KON). Control silages were untreated. Silages were ensilaged in vacuum bags which were opened after a storage period of 12 weeks. After opening chemical composition, microbial quality and aerobic stability were analyzed. The effect of preservatives, dry matter content (DM) (low DM: 114-135 g / kg, high DM ka: 252-305 g / kg) and the proportion of red clover (100-50-0 %) on silage quality and aerobic stability was studied. Sta-tistically significant results between treatments were observed. Wilting increased the quality of silages and well-fermented pure red clover silages were achieved when acid-based additives were used. For example, the concentration of volatile fatty acids was significantly lower than in KON and LAB treatments. In low DM KON and LAB silages very high in acetic acid which didn’t improve aerobic stability in this study but resulted in aerobic unstable silages after around 60 hours. With acid-based additive treated red clover silages, the ratio of ammonia N to total N increased with increasing DM content, which was opposite when compared to other plant materials. This might be due to polyphenoloxidase enzyme (PPO) in red clover, which inhibits the degradation of pro-tein. This study resulted that using silage preservatives is necessary in low DM silages. pH and the content of acetic acid increased with portion of red clover, but lactic acid, propionic acid and etha-nol decreased statistically significantly. AIVB treated silages resulted with same level of quality than other acid-based additive treaded red clover silages, even it was highly buffered to be non-corrosive. The results of this study are useful when choosing preservatives for red clover and gives a new perspective for harvesting silage from pure stands.

The intensification of milk production has increased the size of farms and reduced the use of pastures in recent decades worldwide. The interest in farm animal welfare and the climate impact of dairy products is growing. Offering dairy cows full-time pasture access has declined, but there are other possibilities to provide outdoor access for dairy cows. The aim of this study was to evaluate the effects of two outdoor management systems on the feeding behaviors and productivity of lactating dairy cows. This study was conducted at the University of Helsinki research barn’s freestall and adjacent pastureland in Viikki. The experimental design was a replicated 3x3 Latin square. Twenty-seven Ayrshire cows were divided into nine squares. During the experiment, cows went through three 21-day periods. Cows in squares were assigned to the following treatments: partial access to pasture with sufficient forage for grazing (pasture), partial access to pasture without grazeable forage (paddock), and indoor confinement. Milk yield and ECM were greater in the paddock than in the pasture treatment. Part-time grazing led to an energy deficit because pasture cows had the lowest milk yield. Outdoor access reduced the content of saturated fatty acids and increased the content of monounsaturated fatty acids in milk. Pasture cows spent 30% of their outdoor time eating and paddock cows 27%. Paddock cows used 15% of their total eating time eating TMR and 12% attempting to graze. Pasture cows ruminated the most between 12:00 a.m. and 6:00 p.m., and indoor cows ruminated more than outdoor cows between 7:00 a.m. and 5:00 p.m. Outdoor cows ruminated more than indoor cows from 6:00 p.m. to 11:00 p.m. The cows on the pasture produced less methane per day than the paddock cows. However, methane production in g/kg ECM was not different among groups. According to this study, grazing seems to be a motivating activity for dairy cows. Providing TMR outdoors can be beneficial for the welfare of dairy cows because it enables a choice between feeds and helps to maintain milk yields. Partial outdoor access changed the diurnal pattern of rumination but not the total time used for rumination. There were no differences in milk’s polyunsaturated fatty acid contents between treatments, but eating fresh grass modified the cow’s milk to be healthier.