Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2018
Authors
Lise GrøvaAbstract
No abstract has been registered
Abstract
CAN THE ALERTNESS OF ICELANDIC LEADERSHEEP HELP TO PROTECT SHEEP FLOCKS AGAINST PREDATORS? Emma BRUNBERG 1), Lise GRØVA 2), Emma EYTHÓRSDÓTTIR 3), Ólafur R. DÝRMUNDSSON 4) 1) NORSØK, Norwegian Centre for Organic Agriculture, Gunnars veg 6, 6630 Tingvoll, Norway; emma.brunberg@djurskyddet.se 2) NIBIO, Norwegian Institute of Bioeconomy Research, Gunnars veg 6, 6630 Tingvoll, Norway; lise.grova@nibio.no 3) LBHÍ, Agricultural University of Iceland, Árleyni 22, 112 Reykjavík, Iceland , emma@lbhi.is 4) Jórusel 12, 109 Reykjavík, Iceland, oldyrm@gmail.com Icelandic leadersheep, a unique sub-breed of the North European short-tailed Iceland breed, are known for their strongly inherited alertness and urge to lead their flock. They have been known through centuries for their outstanding behavioural abilities and intelligence and have not been selected for production traits like other Icelandic sheep. The behavioural traits of these sheep have attracted attention; particularly their alertness and the possibility that this could play a role in protecting sheep flocks against predator attacks. Norwegian scientists have shown breed differences in sheep mortality at summer pastures due to predators. A joint Icelandic/Norwegian project was initiated to test the hypothesis that the presence of Icelandic leadersheep affects flock behaviour when exposed to a predator model. Detecting such differences can clearly be regarded as being of both economic and welfare importance. Since it was not feasible to transport Icelandic leadersheep to Norway it was decided to test their alertness in comparison with that of other sheep in Iceland. An experiment was carried out on Hestur Sheep Experimental Farm in W- Iceland during two days in November 2016 using a total of 66 ewes divided into 11 groups. Six of the groups consisted of one Icelandic leadersheep and five Icelandic sheep (LSG), the remaining five groups consisted of six Icelandic sheep (ISG). The predator model tests took place within a fenced, rectangular pasture of 50m x 25m adjacent to a sheep house. All 11 groups were exposed to the same three treatments: human-, dog- and drone test, after a 10 minutes habituation period. The order of the treatments was randomized and there was a minimum 5 minutes interval between each test. All tests were video recorded. The behaviour observations recorded were; eat, stand walk, run and „other“. Recordings were made every 5 seconds during a two-minute period before and after test period, as well as every 5 seconds in 5*30second periods during each of the human, dog and drone treatment. Statistical analyses were conducted using the GLIMMIX procedure in SAS. There was a significant difference in behaviour between the groups with LSG compared to ISG. The LSG spent significantly more time feeding than the ISG groups for all tests, especially in the period after each test was finished, and it hence seems the LSG recover more quickly after a predator test. Including an Icelandic leadersheep into the flock affects behaviour. This should be further elaborated in commercial settings in order to understand the impact and relevance of including this genetic trait in sheep farming. Keywords: sheep, behaviour, predators, Icelandic leadersheep, predator model
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Authors
Venche TalgøAbstract
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Authors
Daniel RasseAbstract
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Abstract
Carbonic anhydrase (CA) plays an important physiological role in all biological systems by accelerating the interconversion of CO2 and HCO3 −. In algae, CA is essential for photosynthesis: external CA (CAext) dehydrates HCO3 −, enhancing the supply of CO2 to the cell surface, and internal CA (CAint) interconverts HCO3 − and CO2 to maintain the inorganic carbon (Ci) pool and supply CO2 to RuBisCO. We frst conducted a literature review comparing the conditions in which CA extraction and measurement have been carried out, using the commonly used Wilbur–Anderson method. We found that the assay has been widely modifed since its introduction in 1948, mostly without being optimized for the species tested. Based on the review, an optimized protocol for measuring CA in Macrocystis pyrifera was developed, which showed that the assay conditions can strongly afect CA activity. Tris–HCl bufer gave the highest levels of CA activity, but phosphate bufer reduced activity signifcantly. Bufers containing polyvinylpyrrolidone (PVP) and dithiothreitol (DTT) stabilized CA. Using the optimized assay, CAext and CAint activities were readily measured in Macrocystis with higher precision compared to the non-optimized method. The CAint activity was 2×higher than CAext, which is attributed to the Ci uptake mechanisms of Macrocystis. This study suggests that the CA assay needs to be optimized for each species prior to experimental work to obtain both accurate and precise results.