Lise Grøva

Research Scientist

(+47) 909 54 835
lise.grova@nibio.no

Place
Tingvoll

Visiting address
Gunnars vei 6, NO-6630 Tingvoll

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

Abstract

Large areas of farmland are abandoned in Norway, which for various reasons are regarded as undesirable. Loss of farmlandmay have negative implications for biodiversity and ecosystem function and food production potential. The objectives of this study were to assess forage mass production and utilization, botanical composition, lamb performance, and grazing distribution pattern when reintroducing livestock grazing to an abandoned grassland. The study area was located in Central Norway, unmanaged for 12 years. Sheep grazed the area for 10 weeks in 2013 and 4 weeks in spring and autumn, respectively, in 2014 and 2015. During the summer of 2014 and 2015, the area was subjected to the following replicated treatments: (1) No grazing, (2) grazing with heifers, and (3) grazing with ewes and their offspring. The stocking rate was similar in the grazed treatments. Forage biomass production and animal intake were estimated using grazing exclosure cages and botanical composition by visual assessment. Effect on lamb performance was evaluated by live weight gain and slaughter traits in sheep subjected to three treatments: (1) Common farm procedure with summer range pasturing, (2) spring grazing period extended by 1 month on the abandoned grassland before summer range pasturing, and (3) spring and summer grazing on the abandoned grassland. Grazing distribution patterns were studied using GPS position collars on ewes. Total annual biomass production was on average 72% higher with summer grazing than without. Annual consumption and utilization was on average 218 g DM/m2 and 70% when summer grazed, and 25 g DM/m2 and 18% without grazing, respectively. Botanical composition did not differ between treatments. Live weight gain was higher in lambs subjected to an extended spring grazing period (255 g/d) compared to common farm practice (228 g/d) and spring and summer grazing on the abandoned grassland (203 g/d), and carcass value was 14% higher in lambs on extended spring grazing compared to common farm practice. In autumn, sheep preferred to graze areas grazed by sheep during summer. Re-introduction of grazing stimulated forage production, and extended spring grazing improved performance in lambs. This study has quantified the value of abandoned grassland as a feed resource.

To document

Abstract

Tick-borne fever (TBF), caused by the bacterium Anaplasma phagocytophilum and transmitted by the tick Ixodes ricinus, has considerable consequences for animal welfare and economy in the sheep industry. Non-invasive, objective methods to quantify chronic stress are needed in order to evaluate the welfare impact of disease. The aim of this study was 1) to evaluate hair cortisol (HC) and hair cortisone (HCn) as biomarkers of chronic stress in sheep with TBF and 2) to test whether there was an association between the development of TBF and con- centrations of HC, HCn and faecal cortisol metabolites (FCM) and body weight. The experiment took place in an area with a high prevalence of TBF, and thirty lambs were used in the study. Wool samples were collected in Week 0, in Week 3 (before turn out on homeland spring pasture), in Week 6 (before turn out on summer rangeland pasture) and at the end of the summer (Week 15). Faecal samples were collected every week (ie. Week 0–6 and Week 15). Symptoms of TBF developed in 15 lambs, of which all recovered from the disease after treatment with antibiotics. HC levels decreased progressively, and significantly, between Week 0, 3, 6 and 15 (p < 0.001), while HCn only decreased from Week 0 to Week 3 (p < 0.001) and then remained stable between Week 3–15. FCM increased between Week 0 and 5 (p = 0.027), and a significant association was found between increased FCM levels in Week 5 and lambs developing clinical signs of TBF (p = 0.022). We also found an association between lambs developing clinical signs of TBF and elevated HCn levels in Week 6 (p = 0.013). A slightly lower weight gain at later time points (Week 6 and 15) were found in the affected lambs compared to clinically healthy lambs. Our results indicate local production and/or metabolism of glucocorticoids in the hair follicles. This study strengthens our previous finding of a potential merit of hair cortisone as a biomarker of chronic stress in sheep.

To document

Abstract

Can sensor technology and real-time communication detect tick-born fever in sheep on range pasture? Introduction: More than two million sheep graze on unimproved, rough grazing land during the summer months each year in Norway. Free ranging sheep are perceived to experience high level of animal welfare through their opportunity to perform natural behaviour, but these benefits are compromised when sheep experience predator attacks, disease and accidents. Ensuring animal health and welfare in farming systems gets increased attention, and new policies and legislations are implemented. About 125 000 sheep (6-7%) are lost on such pastures every year. Tick-borne fever (TBF) is a disease considered to be a major challenge in sheep farming during the grazing season along the coast of south-western Norway. Clinical signs of TBF is often observed within 14 days of infection, starting with an abrupt rise in rectal temperature (often above 41o C). Being able to monitor farm animals on range pastures is increasingly important and implementing available technology for this purpose should be exploited. Implementation of sensor technology in rangeland sheep farming can monitor physiological parameters, such as body temperature (T) and heart rate (HR). Integrating sensors that communicate in a GPS tracking system may contribute to detect, locate and treat sick animals, as well as improve our knowledge of animal health in time and space in rangeland farming systems. Sensors for sheep that communicate with a GPS system is not commercially available today. The objective of the work presented here is to evaluate if temperature sensor information can be used for early detection of tick-borne fever (TBF). Materials and methods: In 2016, temperature sensors (T) (CentiT Star Oddi, Iceland) were implanted in the abdomen of 20 lambs in a sheep flock in a TBF risk area (coastal herd) and in 20 lambs from one flock in a non-TBF risk area (inland heard) in Norway. The sensors were programmed to log temperature every 10 minutes, and were implanted in lambs in early June and collected in early September to retrieve data. The telemetry system (Telespor, Norway) was used on all lambs, and provided real-time positioning data that was used for continuous surveillance on range pasture. All lambs were monitored twice a day for clinical assessment for a one month period after they were turned out on pasture and weight was recorded at birth, spring and autumn. Remaining lambs in the coastal and inland flock were used as control for effect of sensor implantation on weight gain. Number of fever incidences and magnitude of fever was calculated by estimating area under curve (auc) for each temperature incidence for each lamb. Results: In total 32 (80 %) of 40 implanted T sensors could be retrieved. From the coastal herd 17 of 20 T sensors could be retrieved and from the inland herd 15 of 20 Tb sensors could be retrieved. All 17 retrieved T sensors from the coastal herd and all 15 sensors of the inland herd worked as programmed. All lost sensor were not detected at retrieval as no lambs were missing. Temperature of all lambs in both herds ranged from 36.9 °C to 41.8 °C with a mean of 39.6°C (SD 0.35). Sensor implantation did not affect weight gain. There was a significant difference in fever incidences and magnitude of fever in lambs in the TBF risk area (coastal heard) compared to the lambs in the non-TBF risk area (inland herd). Conclusion: The study shows that real-time temperature information in lambs has potential as a disease alarm.

Abstract

SENSOR TECHNOLOGY TO DETECT TICK-BORNE FEVER IN SHEEP ON RANGE PASTURE? Lise GRØVA 1), Boris Fuchs 2), Emma BRUNBERG 3), Unni Støbet LANDE 2), Kristin SØRHEIM 2), Svein Olav Hvasshovd 4), Solveig Marie Stubsjøen 5) 1) NIBIO, Norwegian Institute of Bioeconomy Research, Gunnars veg 6, 6630 Tingvoll, Norway; lise.grova@nibio.no 2) Inland Norway University of Applied Sciences, Campus Evenstad, Elverum, Norway 3) NORSØK, Norwegian Centre for Organic Agriculture, Gunnars veg 6, 6630 Tingvoll, Norway; emma.brunberg@djurskyddet.se 4) NTNU, Norwegian University of Science and Technology, Trondheim, Norway 5) VETINST, Norwegian Veterinary Institute, Oslo, Norway More than two million sheep graze on unimproved, rough grazing land during the summer months each year in Norway. Free ranging sheep are perceived to experience high level of animal welfare through their opportunity to perform natural behaviour, but these benefits are compromised when sheep experience predator attacks, disease and accidents. Ensuring animal health and welfare in farming systems gets increased attention, and new policies and legislations are implemented. About 125 000 sheep (6-7%) are lost on such pastures every year. Tick-borne fever (TBF) is a disease considered to be a major challenge in sheep farming during the grazing season along the coast of south-western Norway. Clinical signs of TBF is ofte observed within 14 days of infection, starting with an abrupt rise in rectal temperature (often above 41o C). Being able to monitor farm animals on range pastures is increasingly important and implementing available technology for this purpose should be exploited. Implementation of sensor technology in rangeland sheep farming can monitor physiological parameters, such as body temperature (T). Integrating such sensors in a GPS tracking system may contribute to detect, locate and treat sick animals, as well as improve our knowledge of animal health in time and space in rangeland farming systems. The objective of the work presented here is to evaluate if a temperature sensor can be used for early detection of Tick-borne fever (TBF). In 2016, temperature sensors (Star Oddi, Iceland) were implanted in the abdomen of 20 lambs in a one sheep flock in a TBF risk area and in 20 lambs from one flock in a non-TBF risk area in Norway. The sensors were programmed to log temperature every 10 minutes, and were implanted in lambs in early June and collected in early September to retrieve data. Temperature data were obtained from 13 temperature loggers from lambs in the TBF risk are and 14 loggers in the non-TBF risk area. The telemetry system (Telespor, Norway) was used on all lambs, and provided accelerometer information and real-time positioning data that was used for continuous surveillance on range pasture. All animals were monitored twice a day for approximately one month period after turned out on tick infested pastures. Number and magnitude of fever was calculated for each lamb. Preliminary results from this study will be presented at the conference. Keywords: sheep, sensor technology, temperature, tick-borne fever, rangeland

Abstract

WOOL QUALITY OF NORWEGIAN WHITE SPÆL SHEEP BREED Lise GRØVA 1), Inger Anne Boman 2) 1) NIBIO, Norwegian Institute of Bioeconomy Research, Gunnars veg 6, 6630 Tingvoll, Norway; lise.grova@nibio.no 2) NSG, Norwegian sheep and goat association, Postboks 104, N-1431 Ås The Norwegian White Speal Sheep are characterised by their fluke-shaped and tapered short tail, dual-coated wool and the ability to thrive under harsh environmental conditions. The income in Norwegian sheep farming comes from lamb meat, wool and pelts. Today, wool is of minor economic importance, commonly accounting for less than 10% of the income. However, the interest of wool as a sustainable and local fibre is increasing. Wool quality traits of the Norwegian White spæl breed has been reported to be declining; i.e. an increase in medulated fibres and in kemp. To address this challenge, there has been developed and incorporated 1) wool quality assessment tutorials for farmers and breeders, 2) included heritability estimates of wool fleece weight and quality class in index calculations, and 3) conducted OFDA analysis of wool from breeding rams for three consecutive years. The work was initiated by the research-project KRUS - Enhancing local wool value chains in Norway (NFR 244618/E50) and has been carried out by NIBIO, the Norwegian Sheep Breeders Association (NSG), Animalia and Norilia. Wool quality assessment tutorials for farmers and breeders are available as a.pdf and video for free download from NSG webpage (nsg.no). A ‘wool evaluation kit’ with a magnifier is available for purchase, also from NSG. Implementing index estimates was made possible when including fleece weigh and fleece classification from all sheared lambs at slaughter into the Norwegain National Sheep Recording system. Further, OFDA analysis were conducted on wool from breeding rams collected autumn 2015, 2016 and 2017. The wool samples were analysed using the optical FD analyser (OFDA100; BSC Electronics Pty Ltd, Western Australia, Australia). OFDA analysis is conducted to describe wool quality traits, development of quality traits over time and also development of quality traits at different age of breeding rams. Preliminary results from this study will be presented at the conference. Keywords: sheep, wool quality, Norwegian white spæl, dual felt, double-coat

To document

Abstract

Tick-borne fever (TBF) is stated as one of the main disease challenges in Norwegian sheep farming during the grazing season. TBF is caused by the bacterium Anaplasma phagocytophilum that is transmitted by the tick Ixodes ricinus. A sustainable strategy to control tick-infestation is to breed for genetically robust animals. In order to use selection to genetically improve traits we need reliable estimates of genetic parameters. The standard procedures for estimating variance components assume a Gaussian distribution of the data. However, tick-count data is a discrete variable and, thus, standard procedures using linear models may not be appropriate. Thus, the objectives of this study were twofold: 1) to compare four alternative non-linear models: Poisson, negative binomial, zero-inflated Poisson and zero-inflated negative binomial based on their goodness of fit for quantifying genetic variation, as well as heritability for tick-count and 2) to investigate potential response to selection against tick-count based on truncation selection given the estimated genetic parameters from the best fit model. Our results showed that zero-inflated Poisson was the most parsimonious model for the analysis of tick count data. The resulting estimates of variance components and high heritability (0.32) led us to conclude that genetic determinism is relevant on tick count. A reduction of the breeding values for tick-count by one sire-dam genetic standard deviation on the liability scale will reduce the number of tick counts below an average of 1. An appropriate breeding scheme could control tick-count and, as a consequence, probably reduce TBF in sheep.

To document

Abstract

Despite global deforestation some regions, such as Europe, are currently experiencing rapid reforestation. Some of this is unintended woodland encroachment onto farmland as a result of reduced livestock pasture management. Our aim was to determine the likely impacts of this on exposure to ticks and tickborne disease risk for sheep in Norway, a country experiencing ecosystem changes through rapid woodland encroachment as well as increases in abundance and distribution of Ixodes ricinus ticks and tick-borne disease incidence. We conducted surveys of I. ricinus ticks on ground vegetation using cloth lure transects and counts of ticks biting lambs on spring pastures, where lambs are exposed to infection with Anaplasma phagocytophilum, the causative agent of tick-borne fever in livestock. Pastures had higher densities of I. ricinus ticks on the ground vegetation and more ticks biting lambs if there was more tree cover in or adjacent to pastures. Importantly, there was a close correlation between questing tick density on pastures and counts of ticks biting lambs on the same pasture, indicating that cloth lure transects are a good proxy of risk to livestock of tick exposure and tick-borne disease. These findings can inform policy on environmental tick control measures such as habitat management, choice of livestock grazing area and off-host application of tick control agents.

To document

Abstract

Tick-borne diseases, such as anaplasmosis and babesiosis, are of major concern for Norwegian sheep farmers. Ticks can be controlled on and off the host, usually with the long-term, high-rotation use of chemicals. Fungal pathogens, predatory mites and ants are thought to be important tick killers in nature. However, the prevalence and diversity of predatory mites in tick habitats has barely been evaluated. It is known that most soil mite species of the cohort Gamasina (order Mesostigmata) are predators. Until now, 220 mesostigmatid species have been reported from Norway, most of them belonging to the Gamasina. One of the first recommended steps in a biological control program involves the determination of the fauna in the pest habitat. The objective of this study was to determine the groups of gamasines co-occurring with I. ricinus in sheep grazing areas in Isfjorden and Tingvoll in Western Norway. A total of 2,900 gamasines of 12 families was collected. The most numerous families were Parasitidae (46.9%) and Veigaiidae (25.7%), whereas the most diverse families were Laelapidae, Macrochelidae, Parasitidae and Zerconidae. Our results showed that the tick density was significantly related only to locality, elevation and rainfall. Differences in the prevailing environmental conditions resulted in more outstanding differences between Gamasina abundances than diversities. Based on our present knowledge of the potential of different gamasine groups as biological control agents, the results suggested that laelapid mites should be among the priority groups to be further evaluated for their role in the natural control of I. ricinus in Norway.

Abstract

Large areas of cultivated grasslands have been abandoned in Norway and are no longer used for production. Knowing that access to spring and autumn pastures is a limiting factor for sheep farmers, this study aims at testing the effect of introducing abandoned farmland into sheep production. One sheep €ock with 83(88) ewes (lambs) in 2014 and 77 (106) ewes (lambs) in 2015 was each year assigned to three treatments: (1) control; common farm procedure with a short spring grazing period before summer grazing on range pasture; (2) spring extended; a four-week extended spring grazing period on abandoned cultivated grassland before summer grazing on range pasture; (3) whole season grazing on abandoned cultivated grassland. Weight gain from spring to autumn, slaughter weight and carcass value were signicantly (P<0.05) higher in lambs assigned to treatment 2, with four weeks extended spring grazing period (255 g day-1, 15.7 kg, 699 NOK), compared to treatment 1 (229 g day-1, 14.3 kg, 615 NOK) and treatment 3 (206 g day-1, 13.2 kg, 548 NOK). !e use of abandoned cultivated grassland for extended spring grazing improved weight gain and slaughter weight, while whole season grazing on abandoned grassland was the least productive option tested.

Abstract

Large areas of cultivated grasslands have been abandoned in Norway and are no longer used for production. Knowing that access to spring and autumn pastures is a limiting factor for sheep farmers, this study aims at testing the effect of introducing abandoned farmland into sheep production. One sheep €ock with 83(88) ewes (lambs) in 2014 and 77 (106) ewes (lambs) in 2015 was each year assigned to three treatments: (1) control; common farm procedure with a short spring grazing period before summer grazing on range pasture; (2) spring extended; a four-week extended spring grazing period on abandoned cultivated grassland before summer grazing on range pasture; (3) whole season grazing on abandoned cultivated grassland. Weight gain from spring to autumn, slaughter weight and carcass value were signicantly (P<0.05) higher in lambs assigned to treatment 2, with four weeks extended spring grazing period (255 g day-1, 15.7 kg, 699 NOK), compared to treatment 1 (229 g day-1, 14.3 kg, 615 NOK) and treatment 3 (206 g day-1, 13.2 kg, 548 NOK). !e use of abandoned cultivated grassland for extended spring grazing improved weight gain and slaughter weight, while whole season grazing on abandoned grassland was the least productive option tested.

Abstract

Large areas of cultivated grasslands are annually abandoned and no longer used for production in Norway. Such areas will over time be encroached by shrubs and trees. Knowing that access to spring and autumn pastures is a limiting factor for sheep farmers, we tested the effect of grazing abandoned grassland on sheep production. We also assessed herbage production by looking at plant community development, pasture production, herbage quality and pasture utilization by sheep and heifers. The experiment was run for two consecutive years; 2014 and 2015. The sheep production was assessed by studying one sheep flock with 83(88) ewes(lambs) in 2014 and 77(106) ewes(lambs) in 2015, which was assigned each year with respect to age of ewe and number of lambs born to three treatments: 1) control; common farm procedure with short spring grazing period before summer grazing on range pasture, 2) spring extended; 4 weeks extended spring grazing period on abandoned cultivated grassland before summer grazing on range pasture, 3) whole season grazing on abandoned grassland. Assessment of herbage production was done by sheep grazing the whole area for one month in spring and autumn. During the summer, the area was assigned to three replicated treatments: a) control with no management, b) grazing heifers and c) grazing sheep with offspring. The stocking rate was 1.8 LU/ha, in both b and c, for a duration of one month. Pasture production and herbage intake was estimated using grazing exclosure cages. Weight gain from birth to autumn as well as slaughter weight were significantly (P<0.05) higher in lambs assigned to treatment 2 with four weeks extended spring grazing period (259 g/day and 15.7 kg) compared to treatment 1 (238 g/day and 14.3 kg) and treatment 3 (216 g/day and 13.2 kg). Herbage consumed during the summer period was on average 211 g DM/m2 and the pasture utilization was 55%. The annual consumption and utilization was 336 g DM/m2 and 62% in the grazed treatments and 28 g DM/m2 and 15% in the control, respectively. Total annual pasture production was on average 72% higher in the grazed treatments compared to the control. There was no difference between the grazed treatments on annual herbage production, herbage intake or pasture utilization. The use of abandoned cultivated grassland for extended spring grazing improved weight gain and slaughter weight of lambs. Further, grazing stimulated herbage production

Abstract

Large areas of cultivated grassland are annually abandoned and no longer used for production in Norway. Such areas will over time be encroached by shrubs and trees, which is regarded as undesirable. We assessed plant community development, pasture production, herbage quality and pasture utilization by sheep and heifers of a grassland that has been unmanaged for 12 years. e experiment was run for two consecutive years. Sheep grazed the whole area for one month in spring and autumn. During the summer, the area was assigned to three replicated treatments: (1) control with no management; (2) grazing heifers; and (3) grazing sheep with off€spring. The stocking rate was 1.8 LU ha-1, in both b and c, for a duration of one month. The area was left resting for a month aer treatment and before autumn sheep grazing. Pasture production and herbage intake was estimated using grazing exclosure cages. Herbage consumed during summer period was on average 211 g DM m-2 and the pasture utilization was 55%. The annual consumption and utilization was 336 g DM m-2 and 62% in the grazed treatments and 28 g DM m-2 and 15% in the control, respectively. Total annual pasture production was on average 72% higher in the grazed treatments compared to the control. Tere was no diff€erence between the grazed treatments on annual production, herbage intake or pasture utilization. Grazing stimulated herbage production, and such abandoned grasslands are valuable forage resources.

Abstract

Large areas of cultivated grassland are annually abandoned and no longer used for production in Norway. Such areas will over time be encroached by shrubs and trees, which is regarded as undesirable. We assessed plant community development, pasture production, herbage quality and pasture utilization by sheep and heifers of a grassland that has been unmanaged for 12 years. e experiment was run for two consecutive years. Sheep grazed the whole area for one month in spring and autumn. During the summer, the area was assigned to three replicated treatments: (1) control with no management; (2) grazing heifers; and (3) grazing sheep with off€spring. The stocking rate was 1.8 LU ha-1, in both b and c, for a duration of one month. The area was left resting for a month aer treatment and before autumn sheep grazing. Pasture production and herbage intake was estimated using grazing exclosure cages. Herbage consumed during summer period was on average 211 g DM m-2 and the pasture utilization was 55%. The annual consumption and utilization was 336 g DM m-2 and 62% in the grazed treatments and 28 g DM m-2 and 15% in the control, respectively. Total annual pasture production was on average 72% higher in the grazed treatments compared to the control. Tere was no diff€erence between the grazed treatments on annual production, herbage intake or pasture utilization. Grazing stimulated herbage production, and such abandoned grasslands are valuable forage resources.

To document

Abstract

A comparative study of clinical manifestations, haematological and serological responses after experimental infection with Anaplasma phagocytophilum in two Norwegian sheep breeds Background: It has been questioned if the old native Norwegian sheep breed, Old Norse Sheep (also called Norwegian Feral Sheep), normally distributed on coastal areas where ticks are abundant, is more protected against tick-borne infections than other Norwegian breeds due to a continuously high selection pressure on pasture. The aim of the present study was to test this hypothesis in an experimental infection study. Methods: Five-months-old lambs of two Norwegian sheep breeds, Norwegian White (NW) sheep and Old Norse (ON) sheep, were experimentally infected with a 16S rRNA genetic variant of Anaplasma phagocytophilum (similar to GenBank accession number M73220). The experiment was repeated for two subsequent years, 2008 and 2009, with the use of 16 lambs of each breed annually. Ten lambs of each breed were inoculated intravenously each year with 0.4 ml A. phagocytophilum-infected blood containing approximately 0.5x106 infected neutrophils/ml. Six lambs of each breed were used as uninfected controls. Half of the primary inoculated lambs in each breed were re-challenged with the same infectious dose at nine (2008) and twelve (2009) weeks after the first challenge. The clinical, haematological and serological responses to A. phagocytophilum infection were compared in the two sheep breeds. Results: The present study indicates a difference in fever response and infection rate between breeds of Norwegian sheep after experimental infection with A. phagocytophilum. Conclusion: Although clinical response seems to be less in ON-lambs compared to NWlambs, further studies including more animals are needed to evaluate if the ON-breed is more protected against tick-borne infections than other Norwegian breeds.

Abstract

Organic Cow Comfort is an advisory tool in animal welfare, developed to secure animal welfare on organic dairy farms in Norway. The farm advisory tool consists of * A farm visit by a veterinarian and a production advisor both specialized in animal welfare and organic farming * An evaluation of herd health and welfare through welfare assessment * Advice on disease prevention and improve-ment of animal welfare * Follow up visit by an advisor looking at im-plementation of new initiatives * Counselling meetings with groups of farmer The evaluation of herd health and welfare is done with the help of checklists where animal based pa-rameters, farm management and operating systems, and human-animal relationship are recorded. A report is prepared after every farm visit with a health and welfare plan where specific measures for improve-ment of animal welfare are outlined.