Abstract

Four different oil-extraction processes have been applied to a batch of double-low rapeseeds, in the pilot plant of CETIOM. The conditions has been chosen with the aim of protecting the proteins from ruminal degradation. They involved cooking temperature (90°C or 130°C) and desolventation parameters (temperature and steam output). Furthermore, six regular rapeseed meals have been collected on feed market.

On these total of 10 rapeseed meals, classical chemical analysis have been done, as well as determinations of in sacco degradation of dry matter and nitrogen in cows.

Introduction

A feedstuff with a high protein content is interesting in compound feed for ruminants if these proteins are not fully hydrolyzed in the rumen and can be digested in the small intestine to provide the animal with essential amino acids. In that respect, about 70% of the proteins of rapeseed meal are hydrolyzed in the rumen, which is a lot as compared to regular soybean meal (62%) and to formaldehyde-treated soybean meal (35%).

Some works have been done, since 1980, with the aim of a better knowledge of relationship between crushing process parameters and nutritional value of meal, by ruminants and monogastrics.

The main works have been done in France (B. Michalet-Doreau, INRA - EURETEC), in Canada (J.R. Ingalls, University of Manitoba, Winnipeg - J.J. McKinnon, University of Saskatchewan, Saskatoon - B.M. Mosimanyana, University of Guelph), in Sweden (M. Emanuelson, University of Uppsala), in Finland (A.O. Vanhatalo, University of Jokionen) and in Poland (H. Kozlowska, University of Olsztyn)

Experimental

In this study, on one hand, 4 different oil-extraction processes have been applied to a batch of double-low rapeseed, in the pilot plant of CETIOM. The conditions has been chosen with the aim of protecting the proteins from ruminal degradation. They involved cooking temperature (90°C or 130°C) and desolventation parameters (temperature and steam output).

On the other hand, six regular rapeseed meals have been collected on feed market.

On these total of 10 rapeseed meals, classical chemical analysis have been done, as well as determinations of in sacco degradation of dry matter and nitrogen in cows (tables 1 and 2).

EURETEC

Table 1 : Analytical and nutritional characteristics of rapeseed meals (%)

Concerning the pilot meals, the protein degradation in the rumen was decreased to 36% by some of the process conditions, while keeping a good digestibility in the small intestine. The digestible protein in intestine for ruminants was increased by up to 46% vs market meals.

However they were not interesting for poultry feed as the digestibility of some amino acids measured in cockerels was reduced.

As for the regular rapeseed meals, their protein values for ruminants showed a large variation : the N degradatibility in the rumen ranged from 58% to 69%, while the N intestinal digestibility ranged from 66 to 80%.

Table 2 : Influence of crushing technology on nutritional value of rapemeal

ECONOMICAL ASPECTS

Economic simulations (table 3) show that decreased rumen degradability of protein results in a gain of interest price of rapemeal.

* 1120 FF/MT

Table 3 : Increased value of rapemeal by crushing technology

Conclusions

These results show the main role played by technologies for improvement of full-fat rapeseed and meal quality. A particular attention is to be done, in the next year, for the glucosinolate content of rapeseed. Further efforts of breeders for reaching very low content of glucosinolates should bring a better competitivity, vs soybean, to rapeseed in animal feeding.

The results (table 5) show that it is possible to reduce the protein degradability of rapeseed meal in rumen to nearly 36% without altering intestine digestibility of aminoacids

Acknowledgments

This work has been carried out by EURETEC II (France) which is a collaboration between feeding industry (Ets ARRIVE, CCPA, GUYOMARCH Nutrition Animale, SANDERS, UCANOR, UNICOPA) and PROLEA organizations (CETIOM, ITCF, ONIDOL, SOFIPROTEOL, UNIP), in the framework of the project EUREKA-EUROPROTEINS (EU623), with a financial support of the French Ministry of Research.