Know more

Our use of cookies

Cookies are a set of data stored on a user’s device when the user browses a web site. The data is in a file containing an ID number, the name of the server which deposited it and, in some cases, an expiry date. We use cookies to record information about your visit, language of preference, and other parameters on the site in order to optimise your next visit and make the site even more useful to you.

To improve your experience, we use cookies to store certain browsing information and provide secure navigation, and to collect statistics with a view to improve the site’s features. For a complete list of the cookies we use, download “Ghostery”, a free plug-in for browsers which can detect, and, in some cases, block cookies.

Ghostery is available here for free: https://www.ghostery.com/fr/products/

You can also visit the CNIL web site for instructions on how to configure your browser to manage cookie storage on your device.

In the case of third-party advertising cookies, you can also visit the following site: http://www.youronlinechoices.com/fr/controler-ses-cookies/, offered by digital advertising professionals within the European Digital Advertising Alliance (EDAA). From the site, you can deny or accept the cookies used by advertising professionals who are members.

It is also possible to block certain third-party cookies directly via publishers:

Cookie type

Means of blocking

Analytical and performance cookies

Realytics
Google Analytics
Spoteffects
Optimizely

Targeted advertising cookies

DoubleClick
Mediarithmics

The following types of cookies may be used on our websites:

Mandatory cookies

Functional cookies

Social media and advertising cookies

These cookies are needed to ensure the proper functioning of the site and cannot be disabled. They help ensure a secure connection and the basic availability of our website.

These cookies allow us to analyse site use in order to measure and optimise performance. They allow us to store your sign-in information and display the different components of our website in a more coherent way.

These cookies are used by advertising agencies such as Google and by social media sites such as LinkedIn and Facebook. Among other things, they allow pages to be shared on social media, the posting of comments, and the publication (on our site or elsewhere) of ads that reflect your centres of interest.

Our EZPublish content management system (CMS) uses CAS and PHP session cookies and the New Relic cookie for monitoring purposes (IP, response times).

These cookies are deleted at the end of the browsing session (when you log off or close your browser window)

Our EZPublish content management system (CMS) uses the XiTi cookie to measure traffic. Our service provider is AT Internet. This company stores data (IPs, date and time of access, length of the visit and pages viewed) for six months.

Our EZPublish content management system (CMS) does not use this type of cookie.

For more information about the cookies we use, contact INRA’s Data Protection Officer by email at cil-dpo@inra.fr or by post at:

INRA
24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

Menu Logo Principal

Home page

The quantification of the main digestive processes in ruminants: the equations involved in the renewed energy and protein feed evaluation systems

INRA Prod. Anim. 26(4) 327-346

D. SAUVANT¹ ,², P. NOZIÈRE³ ,⁴

1 INRA, UMR791 MoSAR, 16 rue Claude Bernard, F-75005 Paris, France
2 AgroParisTech, UMR791 MoSAR, 16 rue Claude Bernard, F-75005 Paris, France
3 INRA, UMR1213 Herbivores, F-63122 Saint-Genès-Champanelle, France
4 Clermont Université, VetAgro Sup, UMR1213 Herbivores, BP 10448, F-63000 Clermont-Ferrand, France

Abstract

The evolution of feeding systems for ruminants towards multiple animal response systems requires the updating of the calculation of nutrient supply to the animals to make it more accurate on aggregated units (UF and PDI) and to allow prediction of absorbed nutrients. This updating is based on the building and interpretation through meta-analysis of large databases of digestion and nutrition of ruminants. Different equations involved in the calculation of UF and PDI have been updated, allowing the following: 1 ) predicting the passage rate of particles and liquid depending on the level of intake and the proportion of concentrate, and taking it into account in order to calculate the ruminal digestion of protein and starch from in situ data; 2) taking into account the effects of the main factors of digestive interactions (level of intake, proportion of concentrate, rumen protein balance) on organic matter digestibility, energy losses in methane and urine; 3) calculating in a more accurate way the energy available in the rumen and the efficiency of its use for microbial protein synthesis. This renewed model leads to the conclusion that UF and PDI values of feed vary depending on the diet, the feed table values being only indicative. It is thus possible to predict the nutrient supply on a wider range of diets more accurately and in particular to better address energy x protein interactions.

Download documents