About the project

Nitrogen (N) is an essential component of human food and animal feeds, but the N-losses during agricultural production are substantial, causing environmental problems and economic losses. Ammonia volatilization from feces and urine increases the eutrophication of surface water bodies, degradation of ecosystems, and threatens human health from atmospheric pollution. Nitrate leakage contributes to environmental degradation and threatens human health. Nitrous oxide, which is an often ignored but very potent greenhouse gas (GHG), contributes 29% of the GHG emissions of livestock, only second to methane (44% of emissions). Excessive N-excretions have caused the current Dutch N crisis, and Norway ranks only 4 places below The Netherlands regarding N-surpluses in Europe. Since most agricultural N-excretions come from the dairy sector which has generally low N use efficiency (typically ~25%), the project aims to develop sustainable genetic and nutrition-based strategies to improve N-efficiency and reduce N-losses in Norwegian dairy cows.

To this end, the project sets out to (1) set up a large reference database of N-use-efficiency and N-losses; (2) develop large scale cost-effective recording methods using IR spectroscopy; (3) develop genomic predictions for the N-efficiency of individual cows and their genetic improvement; (4) detect genes and metabolic pathways that cause high/low N-efficiency and losses; and (5) to optimize the N use in feeding rations of cows and implement these optimizations in a decision support tool to advise farmers.

For these efforts, the multidisciplinary project team contains expertise from animal nutrition, genetics, decision support systems, and relevant industry partners to ensure that the research activities will have their impacts. Thus, this project is well-equipped to improve the dairy sector’s (circular) economy and sustainability, improve its self-sufficiency, and reduce its environmental footprint.

• Background

  • Dairy farming in Norway has become more specialized with an increased demand for optimal nutrient composition of feeds, especially protein content. Norway has limited capacity for producing protein ingredients.
  • To satisfy demands for such nutrients by dairy cows, protein ingredients (e.g., soybean, corn gluten meal, and rapeseed products) are imported to augment protein (nitrogen) in forages. Nitrogen (N) is the most expensive component of the diet, and yet a large part (≳2/3) of the N ingested by dairy cattle is excreted in manure leading to ammonia (NH3) volatilization, nitrate (NO3) leaching, and nitrous oxide (N2O) loss to the wider environment, causing economic losses and damage to the environment. In particular, N loss in the form of N2O contributes substantially to greenhouse gas (GHG) emissions and accounts for 29% of the GHG emissions from the livestock sector, next to methane (which accounts for 44%).
  • However, there is a large potential to improve the N use efficiency (NUE) and reduce emissions from Norwegian dairy cattle both short-term through improved herd management practices and long-term through selective breeding. Therefore, this project will develop methods needed for genomic selection which would result in sustainable and permanent reductions of the environmental footprint of dairy production systems. In general, the project will thus contribute to more sustainable and self-sufficient Norwegian dairy farming systems with reduced environmental impact, GHG emissions, and increased profitability of the dairy farms, which aligns also with the government’s strategy for bio-economy.
• Objectives

  The main aim of the project is to develop new models and methods needed to accurately predict nitrogen traits for selective breeding and feeding strategies for Norwegian dairy cows. This will help improve their nitrogen efficiency and reduce nitrogen losses, thereby improving the dairy sector’s economy and reducing its environmental footprint.

  Specific objectives:

  1. generate reference phenotypes for N-traits in Norwegian dairy cows and evaluate the factors affecting them.
  2. develop milk spectral-based calibration models to predict the N-traits on a routine basis in individual dairy cows.
  3. estimate genetic parameters and predict genomic breeding values for N-traits.
  4. unravel the genetic architecture of N-traits using genome-wide association studies.
  5. optimize feeding management concerning N-traits, including the optimizations in a decision support system that helps farmers in planning and evaluating rations for dairy cattle.
• Participants

  NMBU participants

  External participants

  TINE SA - Håvard Nørstebø
  GENO SA - Bjørg Heringstad
  Felleskjøpet Forutvikling - Linda Karlsson