Grete H. M. Jørgensen

Research Scientist

(+47) 407 66 769
grete.jorgensen@nibio.no

Place
Tjøtta

Visiting address
Parkveien, 8861 Tjøtta

Biography

Education and areas of interest:

PhD within ethology with emphasis on animal environment and animal welfare. Have been working with thermoregualtion, climate, sensortechnology and animal preferences. My PhD project dealt with physical and social environment for sheep during the long indoor feeding period. 

Professional qualifications:

  • Experienced project leader within the NIBIO system. I have also worked for the Forskerforbundet organisation.
  • Competence within data processing and statistical analysis. 
  • Scientific co-supervisor for several bachelor and masters students. Experience as teacher, lecturer and cesor.
  • Have been publishing international papers on many different animal species. 
  • Themoregulation and social behaviour in horses.
  • Experience with measurement of methane from ruminants (respiration chambers and the SF6 method)
  • Development and testing of sensor technology for surveillance of animals both in barns and on rangeland pastures. 
  • Experience as project leader for several reindeer projects. For example: Stress and welfare for reindeer during handling, Health risks and hazards for reindeer herders, welfare indicators for reindeer and virtual fencing. 
  • Participated in several INTERREG projects. For example Animal Sense (Interreg Botnia Atlantica 2012-2019)
  • Is appointed Person with special control responsibility for the animal welfare unit in NIBIO, and at the endorsed research animal facility at Tjøtta.

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Abstract

Biochar, which is the product of biomass pyrolysis, has been suggested as a feed supplement to improve performance in livestock systems and reduce greenhouse gas emissions. The aim of the current study was to investigate in vitro and in vivo potential of biochar to favourably modify rumen fermentation (e.g., an increase in total Short Chained Fatty Acid (SCFA) concentration and a change in SCFA profile), reduce methane emission and increase sheep growth performance. Four concentrates were produced with biochar inclusion of 0, 10, 23 and 46 g/kg DM. The experimental diets for the in vitro experiments consisted of straw and concentrate in a 60:40 ratio and included measurements of total gas and methane (CH4) production, pH, ammonia nitrogen, SCFA, and microbial assays (total bacteria and methanogenic archaea). Two in vivo experiments were performed where the animals received ad libitum forage with 0.4 kg concentrate daily. Experiment 1 investigated the daily DM intake of sheep while experiment 2 investigated daily growth rate and CH4 emission of lambs. The inclusion of biochar had no impact on in vitro total gas production (ml/200 mg DM substrate) (P = 0.81) and CH4 production (ml/200 mg DM substrate) (P = 0.93). In vitro total SCFA concentration increased (P < 0.05) while acetate to propionate ratio (A:P) tended to decrease (P = 0.05) with both doses of biochar. Total bacteria decreased with the highest biochar inclusion in vitro (P < 0.05). Sheep’s DM intake (kg/d) increased when low and medium levels but not when a higher level of biochar was added to the diet (P < 0.001). The inclusion of biochar did not significantly impact the lamb’s daily growth rate (g/d) (P = 0.61) or enteric CH4 emissions (g/kg DM) (P = 0.43). We conclude that biochar supplementation had no favourable impacts on in vitro and in vivo CH4 production or on lamb’s growth rate. Further research with well-characterised biochar is needed to gain a better understanding of the potential of biochar as a feed additive for ruminant livestock.

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Abstract

CONTEXT European dairy cattle production systems (DPS) are facing multiple challenges that threaten their social, economic, and environmental sustainability. In this context, it is crucial to implement options to promote the reconnection between crop and livestock systems as a way to reduce emissions and enhance nutrient circularity. However, given the sector's diversity, the successful implementation of these options lacks an evaluation framework that jointly considers the climatic conditions, farm characteristics, manure management and mineral fertilisation practices of DPS across Europe. OBJECTIVE This study aims to develop a modelling and statistical framework to assess the effect of climatic conditions, farm characteristics, manure management and mineral fertilisation practices on the on-farm sources of greenhouse gas (GHG) emissions and nitrogen (N) losses from ten contrasting case studies for dairy production across Europe, identifying options for emissions mitigation and nutrient circularity. METHODS Using the SIMSDAIRY deterministic whole-farm modelling approach, we estimated the GHG emissions and N losses from the ten case studies. SIMSDAIRY captures the effect of different farm management choices and site-specific conditions on nutrient cycling and emissions from different components of a dairy farm. In addition, we applied the Factor Analysis for Mixed Data multivariate statistical approach to quantitative and qualitative variables and identified relationships among emissions, nutrient losses, and the particular characteristics of the case studies assessed. RESULTS AND CONCLUSIONS The results showed how intensive case study farms in temperate climates were associated with lower enteric emissions but higher emissions from manure management (e.g. housing). In contrast, semi-extensive case study farms in cooler climates exhibited higher N losses and GHG emissions, directly linked to increased mineral fertilisation, excreta during grazing, and slurry application using broadcast. Furthermore, the results indicated opportunities to improve nutrient circularity and crop-livestock integration by including high-quality forages instead of concentrates and substituting mineral fertilisers with organic fertilisers. SIGNIFICANCE The presented framework provides valuable insights for designing, implementing, and monitoring context-specific emission mitigation options and nutrient circularity practices. By combining whole-farm modelling approaches and multivariate statistical methods, we enhance the understanding of the interactions between sources of N losses and GHG emissions. We expect our findings to inform the adoption of emissions reduction and circularity practices by fostering the recoupling between crop and livestock systems.

To document

Abstract

Understanding the environmental consequences associated with dairy cattle production systems is crucial for the implementation of targeted strategies for emission reduction. However, few studies have modelled the effect of tailored emission mitigation options across key European dairy production systems. Here, we assess the single and combined effect of six emission mitigation practises on selected case studies across Europe through the Sustainable and Integrated Management System for Dairy Production model. This semi-mechanistic model accounts for the interacting flows from a whole-farm perspective simulating the environmental losses in response to different management strategies and site-specific conditions. The results show how reducing the crude protein content of the purchased fraction of the diet was an adequate strategy to reduce the greenhouse gas and nitrogen emission intensity in all systems. Furthermore, implementing an anaerobic digestion plant reduced the greenhouse gas emissions in all tested case studies while increasing the nitrogen emissions intensity, particularly when slurry was applied using broadcast. Regarding the productivity increase, contrasting effects were observed amongst the case studies modelled. Moreover, shallow slurry injection effectively mitigated the intensity of nitrogen losses from the fields due to strong reductions in ammonia volatilisation. When substituting urea with ammonium nitrate as mineral fertiliser, site-specific conditions affected the mitigation potential observed, discouraging its application on sandy-loam soils. Rigid slurry covers effectively reduced the storage-related nitrogen emissions intensity while showing a minor effect on total greenhouse gas emission intensity. In addition, our results provide novel evidence regarding the advantages of cumulative implementation of adapted mitigation options to offset the negative trade-offs of single-option applications (i.e. slurry covers or anaerobic digestion and slurry injection). Through this study, we contribute to a better understanding of the effect of emission mitigation options across dairy production systems in Europe, thus facilitating the adoption of tailored and context-specific emission reduction strategies.