Doctoral theses (IHA)
Unless otherwise stated on the individual theses, the works in this collection are licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Recent Submissions
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Designing the optimal free stall for dairy cows : effects of free-stall design on cleanliness, milk yield, health, and behaviour
(PhD Thesis;2011:42, Doctoral thesis, 2011)Liggebåsens utforming er av stor betydning for blant annet hygiene og kuenes atferd i et løsdriftfjøs ettersom kua tilbringer hoveddelen av tida si her, hovedsakelig liggende men også stående i båsen. For å unngå at kua ... -
Essentials for sustainable dairy goat breeding program in Tanzania
(PhD Thesis;2016:53, Doctoral thesis, 2022-11-15)The overall objective of this thesis was to develop building blocks essential for establishing a sustainable dairy goat breeding program in Tanzania. To fulfil this objective, three approaches were employed. This included ... -
Effect of cobalt on fatty acid composition in milk of dairy cows and sows
(PhD Thesis;2011:75, Doctoral thesis, 2011)Previous research revealed that supplementing excess cobalt (Co) reduces bovine milk content of monounsaturated fatty acids (MUFAs), probably mediated by the enzyme Δ9 -desaturase. The general aim of this research project ... -
Protein quality evaluation of animal protein ingredients applied in extruded dry dog food using mink (Neovison vison) as a model species
(PhD Thesis;2016:78, Doctoral thesis, 2020-11-24)Determination of protein and amino acid (AA) digestibility is essential for protein quality evaluation of dog foods, and should preferably be measured as standardized ileal digestibility (SID). Assessment of protein ... -
Density dependent foraging ecology and performance of domestic sheep on alpine ranges
(PhD Thesis;2012:2, Doctoral thesis, 2012)Populations of large herbivores are strongly influenced by density dependent and independent processes such as climatic variability, which have common effects on individual performance and demographic rates. However, little ... -
Genetic analyses of claw health in Norwegian Red
(PhD Thesis;2015:67, Doctoral thesis, 2015)The main objective of this PhD-study was genetic analyses of claw disorders recorded at claw trimming, to exploit the most efficient way of including claw health in the breeding scheme of Norwegian Red. Claw health data ... -
Rearing Norwegian Red heifers : growth and effects on subsequent milk production of primiparous cows
(PhD Thesis;2015:48, Doctoral thesis, 2019-01-07)The thesis is part of a larger research project aiming to determine the impact of calf and youngstock development on dairy cow production and profitability. Paper I utilized field data to find a more marginal effect of ... -
Aerobic exercise training for improving robustness of Atlantic salmon (Salmo salar)
(PhD Thesis;2012:29, Doctoral thesis, 2012)Exercise training produces a wide range of benefits to fish kept in captivity. Research has shown that among several other parameters, growth, feed efficiency, feed intake and cardiac capacity are improved. In higher ... -
Linking the heritability concept to systems dynamics
(PhD Thesis;2013:18, Doctoral thesis, 2013)The concept of heritability is rooted in the observation that relatives resemble one another more than expected by chance. Narrow-sense heritability is defined as the proportion of phenotypic variance that is attributable ... -
Interactive effects of dietary and environmental challenges on digestive function and intestinal homeostasis in rainbow trout (Oncorhynchus mykiss)
(PhD Thesis;2016:82, Doctoral thesis, 2016)Aquaculture is challenged by various dietary and environmental factors. A widely debated and studied dietary challenge is the inclusion of plant ingredients containing anti-nutritional factors (ANFs) in salmonids diet. ... -
Hydrolysis of Atlantic salmon (Salmo salar) rest raw materials : influence of process conditions and evaluation of hydrolysate in diets for broiler chickens and piglets
(PhD Thesis;2015:85, Doctoral thesis, 2018-04-25)Annually Norway produces 1.3 million tons of Atlantic salmon and the levels of production are still rising. After withdrawal of eviscerated fish and filet, 336 000 tons of rest raw material are available for further ... -
Genetic analyses of feed efficiency traits in pigs
(PhD Thesis;2016:55, Doctoral thesis, 2017-12-12)The main objective of this thesis was to establish more detailed measurements feed efficiency in Norwegian Landrace and Norwegian Duroc in order to genetically improve this trait without negative consequenses for other ... -
A comparison of organic grass-clover silages from primary growth and regrowth in dairy cows
(PhD Thesis;2016:24, Doctoral thesis, 2017-12-06)The annual milk yield of Norwegian organic dairy cows increased by 18% in 2013 compared to 2007 levels. The increased milk yield in this period was achieved by increased levels of concentrate feed in the diet. Given that, ... -
Improving the accuracy of genomic predictions in numerically small populations
(PhD Thesis;2016:20, Doctoral thesis, 2017-12-06)Genomic selection (GS) is increasingly being implemented in livestock, especially in the dairy cattle sector. While dairy cattle populations such as Holsteins have benefitted greatly from GS in the accuracy of evaluation ... -
Inbreeding determined by the amount of homozygous regions in the genome
(PhD Thesis;2015:41, Doctoral thesis, 2017-11-30)The main aim of this PhD was to study long homozygote segments present in the genome in Norwegian Red, and find genomic options to measure inbreeding more accurately than from a pedigree database. Prior to the study, runs ... -
Strategies for improving dairy goat kid rearing systems for milk and meat production in Norway, Tanzania and milk utilization in Malawi
(PhD Thesis;2011:50, Doctoral thesis, 2011)Kid rearing strategies are a key to continuous supply of milk to Dairies and reduction of kid rearing cost that will also optimize farmer’s income by increasing by-products and maintaining the beautiful cultural landscape ... -
Tick-borne fever in sheep : production loss and preventive measures
(PhD Thesis;2011:32, Doctoral thesis, 2011)A major challenge in sheep farming during the grazing season along the coast of southwestern Norway is tick-borne fever (TBF) caused by the bacteria Anaplasma phagocytophilum, that is transmitted by the tick Ixodes ricinus. ... -
Quantitative genetics of traits related to disease resistance and effects of vaccination in Atlantic salmon (Salmo salar)
(PhD Thesis;2011:39, Doctoral thesis, 2011)Disease resistance is of major importance to the fish farming industry as disease outbreaks have negative effects on the industry’s economy, its reputation and on fish welfare. Today, almost all fish in the Norwegian salmon ... -
Optimal use of plant protein concentrates in extruded feeds for carnivorous fish
(PhD Thesis;2011:53, Doctoral thesis, 2011)The main objective of the research presented in this thesis was to evaluate multiple amino acidsupplemented plant protein concentrates as the main protein source in diets for carnivorous fish. This objective was approached ... -
Upgrading plant ingredients in feed for salmonids by thermo-mechanical treatment and acid salts
(PhD Thesis;2011:52, Doctoral thesis, 2011)Inclusion of plant ingredients in diets for salmonids is restricted due to low energy contents, unbalanced amino acid (AA) composition and presence of antinutritional factors (ANF). The objective of this thesis was to ...