Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2024
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Jorunn BørveSammendrag
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The aim of this study was to compare various types of peat-free or peat-reduced growing media on growth and flowering of ‘Purple piruette’ petunia hybrids. In experiment 1, 30 variants of growing media, including commercial peat-based growing media, different peat-reduced and peat-free mixtures based on garden/park waste compost and wood fiber were tested. All the peat-free variants failed in producing normal, healthy plants without chlorosis. A commercial peat-reduced growing medium with peat, garden/park waste-compost and crushed rock material (0-2 mm), base fertilized with chicken manure, and similar growing media mixtures with other types of base fertilizer gave larger plants with more flowers than the peat-based reference. The highest performing mixture with the smallest amount of peat (35% wood fiber, 30% garden park/park waste-compost, 30% peat and 5% sand) gave equal results as the commercial peat-reduced growing medium. In experiment 2, further studies of the effect of peat reduction by incorporation of wood fiber and four compost types were performed. The effect of start fertilizer incorporation to the substrates was also assessed. One of the peat-free variants with compost and wood fiber gave normal plants with rich flowering but didn’t reach the performance of pure peat on plant size. The pH (H2O) of the composts seems to be a key factor for successful substrate mixtures of compost and wood fiber. The composts with highest pH gave small plants and start fertilizer had no effects on the growth. The results show that there is a potential for development of peat-free substrates based on compost and wood fiber presuming that pH (H2O) of the composts is not too high.
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Cornelya Klutsch Junbin Zhao Mikhail Mastepanov Hanna Marika Silvennoinen Juho Vuolteenaho Erling Fjelldal David Kniha Runar Kjær Snorre HagenSammendrag
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Interest in dairy cow-calf contact (CCC) systems is growing, yet limited research had been focused on CCC in a pasture setting. Our study aimed to evaluate the performance of pastured dairy cows and calves with or without CCC through machine milk yield and composition, cow body condition score (BCS) and body weight (BW) decrease, and calf body weight gain (BWG). We also examined calf intake of concentrates, artificially reared calves’ milk intake, and the health of both cows and calves. Conducted on a commercial dairy freestall farm and summer farm in Norway from May to August 2021, the study included twenty cow-calf pairs: 17 Norwegian Red (NRF) and three NRF × Holstein crossbreeds. They were divided into two treatments: cow-calf contact (CC, n = 10) or early separation (ES, n = 10), each with two groups of five cow-calf pairs. CC pairs had full CCC on pasture until 6 weeks postpartum and part-time contact in weeks 7 and 8 (weaning). ES pairs were separated 1–3 h after birth, kept on separate pastures with no contact between ES cows and calves. ES calves’ received daily milk allowances of 12–14 L (weeks 0–6), reduced to 8 L (week 7) and further to 4 L (week 8). From week 9, all calves were denied access to any milk (ES) or cows (CC). During weeks 0–6, CC cows had a daily machine milk yield 23.7 kg lower/cow than ES cows. The difference was likely affected by nursing and other factors (parity and inhibited milk ejection), and persisted during weaning, with CC cows delivering 8.3 kg less/cow/day in weeks 10 and 11 postpartum. Fat and protein content in machine milk showed no significant difference, while lactose content was lower in milk from CC cows than ES cows (week 5 postpartum). CC cows had a lower BW decrease compared to ES cows (CC: 913 g/day, ES: 1415 g/day from pasture day one through week 9). ES calves had an average milk intake of 10.7 L/calf/day (weeks 0–6), and consumed more concentrates than CC calves. Calves’ daily BWG did not differ between treatments in weeks 0–6 (CC: 1340 and ES: 1250 g/day) and decreased for both treatments during weaning (CC: 1050 g/day, ES: 920 g/day in weeks 6–9). Inhibited milk ejection during machine milking was a challenge in CC cows, prompting oxytocin injections to prevent mastitis. Allowing calves full CCC or providing whole milk near ad libitum can result in similar BWG and health in calves. Further research should explore strategies to enhance milk ejection in pastured CCC cows.