Work Package (WP) 5 – Nutrition-microbiome-emissions/product quality interactions

WP Leader: Pekka Huhtanen
Email: pekka.huhtanen[at]slu.se

Changes in the main components of the diet are known to affect the efficiency of digestion and nutrient utilisation in the ruminant and are a major determinant of the overall impact of ruminant production on the environment and product quality in terms of the fatty acid composition of meat and milk. Understanding the role of key nutrients – carbohydrate, protein and fat – in the diet on the composition and function of the ruminal microbiome will provide an insight into the mechanisms whereby changes in diet composition alter rumen function and nutrient use and offers a platform for developing more efficient diets in the future. Diets with different predominant energy substrates influence both methane and nitrogen emissions: how is this reflected in the balance of protozoa, bacteria and archaea in the microbiome? Do protein-rich diets result in different communities of key protein-metabolizing bacteria in comparison with protein-adequate or deficient diets? Medium chain fatty acids and plant oils decrease methanogenesis, alter fibre digestion, and also affect the fatty acid composition of meat and milk: can these changes be explained by a comprehensive analysis of the microbiome?

Aim

To understand the role of diet and nutrient supply on the composition and function of the rumen microbiome by:

• Characterising the impact of dietary carbohydrate on the composition and function of the rumen microbiome in lactating cows.
• Examining the effect of dietary protein content and composition on the composition and function of the rumen microbiome in lactating cows.
• Determining the influence of fatty acids and plant oils on the composition and function of the rumen microbiome in lactating cows.

Major Outcomes

• Report on the influence of different-carbohydrate diets on lowering methanogenesis, altering milk fatty acids and on the bovine rumen microbiome.
• Report on the influence of different-protein diets on lowering methanogenesis, altering milk fatty acids and on the bovine rumen microbiome.
• Report on the influence of different lipid supplements in the diets on lowering methanogenesis, altering milk fatty acids and on the bovine rumen microbiome.