ABSTRACT

A five-year research programme (1993-1997) has been lead with the european label EUREKA. This collaborative linkage of french and dutch partners, named EUROPROTEINS programme, was the continuation of a previous five-year collaboration (1988-1992) named IMPROFEED. The main purpose of EUROPROTEINS research program was to increase nutrients accessibility of rapeseed, sunflower and peas by poultry and ruminants through fitting technologies.

In France, the works were carried out in close collaboration with CETIOM (and PROLEA organisations) and feeding industry.

INTRODUCTION

Increasing nutrients accessibility (protein, energy) by monogastric animals is a priority for feeding industry. Expected progress of a better knowledge of raw materials are a higher incorporation rate in feed, feeding cost reduced and less nitrogen and phosphorus wastes. Full-fat rapeseed have interesting nutritional characteristics for animal feeding : high fat content : 45−50%) and high protein content : about 20% (dry matter basis basis).

However several factors prevent from an optimal use of wholeseeds in feed : variability of their chemical composition and their nutritional value, feed technology impact, the impact of the residual glucosinolates...

The aim of the study was to evaluate the extend of the nutritional value variability of full-fat rapeseed and to understand the origin from chemical and technological factors.

1 - FRENCH AND EUROPEAN CONSUMPTION OF FULL-FAT RAPESEED

Consumption of full-fat rapeseed in France and European Union has been markedly increased between 1990/91 and 1993/94, but becomes stabilized since 1993 and is decreasing since 1996. This evolution is essentially due to new CAP's economical rules which give much less interest for direct uses of seeds vs meals.

1000 MT France

Sources : SCEES, ONIDOL, SIDO

1000 MT E.U

Sources : Oil World

* forecast

Table1: French and european consumption of full-fat seeds

2 - METABOLIZABLE ENERGY OF FULL-FAT RAPESEED : VARIABILITY

Chemical composition

Two sets of rapeseed batches were collected in 1993 and 1995. Chemical compositions were determined. The main values are reported in table 2 and show the quite big variations of fat, protein, fiber, NDF and glucosinolate contents : Fat content ranged from 44 to 49 %, protein content from 17 to 22%, fiber content from 7 to 9%, NDF content from 12.5 to 16% and the total glucosinolates content from 7 to 22 µmoles/g (dry matter basis).

Table 2 : Chemical composition of full-fat seeds

Metabolizable energy

The seeds were incorporated at a level of 20% in a feed made of wheat, maize and soybean meal. The feed was pelleted and given ad libitum to adult cockerels for metabolisable energy (ME) determinations. The ME values of the rapeseeds were calculated by difference with the control diet. Regression analysis have been performed on the two sets and both sets together.

The ME values of the rapeseeds ranged from 4800 to 5200 kcal/kg DM for the 1993 set, and from 4900 to 5400 kcal/kg DM for the 1995 set.

The difference between extreme values of AMEn is 400 kcal/kg DM for seeds cropped in 1993 and 480 kcal/kg DM for seeds cropped in 1995. The AMEn values for the 1995 seeds are higher by 200 kcal on average, as compared to the 1993 seeds values. This can be explained by the higher input of mechanical energy during pelleting of the 1995 feeds due to a lower moisture content, compared to the 1993 feeds.

Fat digestibility of the seeds went from 88% up to 92% for the 1993 set, and from 90% up to 94% for the other.

Linear regressions have been carried out between AMEn (and AMEn/GE) and chemical values

(table 3).

Concerning the 1993 rapeseeds, the results show that 87% of AMEn variations of the 1993 rapeseeds were explained by fat content (positive effect) and ADF content (negative effect). The AMEn/GE variations were explained at 85% by fat content (positive effect) and ADF content (negative effect), or at 83% by fat content (positive effect) and indolylglucosinolates (negative effect).

Concerning the 1995 rapeseeds, 79% of AMEn variations were explained by fat content (positive effect) and total glucosinolates content (negative effect). The range of glucosinolates was broader for the 1995 set than for the 1993 set (6.7 to 22.3 µmol/g DM vs 9.3 to 17.5 µmol/g DM).

The AMEn/GE variations were explained by indolylglucosinolates at 55% (negative effect) and by alkenylglucosinolates at 31% (negative effect).

For both sets taken together, 65% of AMEn variations were explained by fat content (positive effect) and total glucosinolates content (negative effect).

Taking into account the temperature (degrees celsius) brought during pelleting, 14 extra percentage of the variation (positive effect) were explained.

The AMEn/GE variations were explained at 67% by fat content (positive effect), indolylglucosinolates (negative effect) and temperature brought during pelleting (positive effect).

Table 3 : Factors explaining variations of metabolizable energy by poultry

3 - ECONOMIC ASPECTS

Economic simulations show that increased metabolizable energy (vs normal full-fat rapeseed with 4200 kcal/kg DM) results in a higher interest price of seeds for feeding (table 4).

* 1350 FF/MT

Table 4 : Increased value of full-fat rapeseed through higher metabolizable energy

These increased values are much more profitable for feeding industry with a quite higher potential for using wholeseeds.

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.