Link: bioethanol co-products for livestock (ENBBIO)

Results:

The ENBBIO ruminant studies achieved their primary objective, which was to evaluate wDDGS from UK bioethanol production in terms of nutritional value and animal responses to inclusion in typical ruminant diets. The first dairy trial gave an apparent limitation of wDDGS inclusion of ~20% of diet dry matter. Digestibility studies confirmed that there was no significant effect of wDDGS inclusion level on dry matter digestibility. A second dairy trial re-examined the effect of inclusion level of wDDGS. For this trial, diets were formulated with ME values and degradation characteristics determined in vivo for the actual batch of wDDGS to be tested. With an accurate ME value, there was no effect of wDDGS inclusion level on intake or performance up to inclusion rates of 22% DDGS in ration dry matter.

In the dairy diets inclusion of wDDGS did not affect daily methane output, which may have been due to the relatively high level of concentrates fed in the control ration, given that early lactation cows were used in the study.  In contrast, metabolism work with sheep fed at maintenance showed that methane output was reduced (g/kg DMI) when diets contained DDGS, compared to feeding hay alone.

In a survey of wDDGS use on commercial beef farms, inclusion levels of 12.5% and 30% of the diet supported good performance levels.

Dairy and beef farmer messages:

Important considerations during formulation of diets containing high proportions of DDGS are:

• Accurate estimations of ME value and degradability characteristics of specific DDGS batches are required for accurate ration formulation.
• ME value and degradability characteristics vary with type of DDGS and to some extent source crop, drying process and addition of solubles. It is always worth getting an analysis of the product used in a ration to ensure an accurate formulation.
• In this project inclusion levels up to 22% wDDGS in the dry matter of dairy cows rations had no negative effects on dairy cow intake or performance.

The Problem:

The emerging bioethanol industry means that higher inclusion rates of W-DDGS are expected in UK livestock diets than has been the norm, and that there is an urgent need for research on nutritional values and effects of dietary inclusion rates of this potentially valuable raw material.  Distillers Dried Grains with Solubles (DDGS) have the potential to reduce reliance on imported soya, or other protein feeds in livestock diets. This not only has implications for cost of production but also environmental concerns relating to land use change and, specifically, the release of carbon from cropping of high carbon stock soils.

Project Aims:

The aim of this proposal is to quantify sources of variability in W-DDGS, identify opportunities to enhance their value, to consider innovative processes to reduce fibre content (for non-ruminants) and to quantify the contribution of the co-products to the overall GHG balance of UK crop, livestock and ethanol production.

Approach:

Studies will address both ruminant and non ruminant livestock. Relevant to ruminants there will be work to investigate nutrient utilisation, methane emissions and production responses. A multitude of scientific publications are expected to result from this work as well as much highly relevant information for commercial beef producers.

Deliverables:

The Objectives will be to:

1. Quantify the chemical composition of UK sources of W-DDGS and other co-products including development of appropriate methodologies,
2. Identify the limitations associated with feeding UK sources of W-DDGS in both ruminant and non-ruminant species,
3. Identify routes to improving nutritional value of DDGS through production of consistent products from modern biorefineries, making use of process modifications in the biorefinery, and the use of enzymes to improve animal performance,
4. Test the modified and improved DDGS products using ruminant and non-ruminant species
5. Quantify the overall benefits of DDGS production on reducing diffuse pollutants (methane, N and P), and enhancing home-grown protein production,
6. Ensure effective knowledge transfer of research outputs.