Crambe has been successfully grown and processed on a commercial scale in North Dakota for a number of years, although acreage has varied. The future production levels appear to be far more stable with the development of a new company, AgGrow Oils Limited Liability Company(LLC). This company is establishing long term markets for the high erucic acid oil from crambe. The residual meal will be available in larger and more consistent supplies as a protein source for ruminant livestock or other uses. AgGrow Oils will process crambe using mechanical extraction methods rather than pre-press solvent extraction, used in previous crambe crushes. The mechanical extraction process involves reducing the particle size of the seed, extrusion, conditioning to lower moisture content with heat, and two final passes through expellers to remove the oil. The remaining meal will have higher lipid or fat content than solvent meal as mechanical oil extraction is less efficient. In addition, extruded meals have higher proportions of escape protein. This is protein that is slightly altered during the heating/crushing process so it is not degraded as readily by the microbes in the rumen. Higher levels of this "escape" protein are more useful to stressed or very high production ruminants or can be balanced with non-protein nitrogen sources for more economical supplements.

Crambe will be processed throughout the year at the AgGrow Oils plant at Carrington ND with scheduled intermittent crushes of other minor oil seeds. Meal will be available continually from contract purchases or on the spot market. The plant is under construction and expects to be on line prior to Jan. 1, 1998.

This paper presents results of comparative laboratory analysis of crambe meal from pre-press solvent vs meal from a small scale test crush using mechanical expeller extraction.

Crambe Meal Samples and Analyses

A crambe meal sample from the commercial 1996 crush conducted at the Archer Daniels Midland Inc. oilseed plant at Enderlin, ND was used as a representative of the solvent extraction process. Meal samples from a mechanical extraction test crush conducted by Anderson International, Cleveland OH using crambe seed grown in the 1996 season were used as the expeller sample. Both crushing processes used whole crambe seed. Nutrient levels for expeller extraction in Table 1 were adjusted to a residual lipid content of 5% based on expected extraction efficiency at the AgGrow crushing facility. All samples were run in duplicate at respective laboratories with coefficients of variation at less than 2%.

Proximate analysis was conducted by Ingman Laboratories Inc., Minneapolis, MN. The glucosinolate analysis was conducted by POS Pilot Plant Corp. Laboratory, Saskatoon, SASK. This laboratory has substantial experience in glucosinolate analysis and meets the standards established by FDA-Center for Veterinary Medicine for quality control. Glucosinolate content is calculated on an oil free basis.

Discussion

Nutrient content of the 1996 meal appears to be similar for both processing methods except for the fiber components. Crude fiber (Proximate analysis), and ADF - NDF (VanSoest fiber components) all appear to be higher for the expeller extraction processed meal. The commercial value of the meal for ruminants will be based largely on the protein content with little concern for the amount of fiber. Glucosinolates contained in expeller meal appear to be substantially higher than solvent meal. This may be the result of the activation on an enzyme during the seed conditioning, and mechanical extraction, which is a more heat intense, pressure process than solvent extraction.

However, at normal protein supplement usage levels, this should not pose a problem. Anderson et al., (1993) reported feedlot steers fed 13.43% of diet dry matter as crambe meal (65.5 umoles per gram) resulting in 8.8 umoles/gram glucosinolate intake, consumed the same and gained the same as steer fed no crambe meal or intermediate amounts. If expeller crambe meal is included at less than 4.2% of dry matter intake, the current FDA ruling, glucosinolates levels will be below the maximum level tested. Additional ruminant studies are planned in the near future.

Crambe meal has proven to be a useful and cost effective protein supplement. At highly competitive prices, feed companies and producers in the region will have an opportunity to reduce production costs with crambe meal without affecting animal performance.

Table 1. Proximate analysis and glucosinolate content of crambe meal from pre-press solvent vs mechanical expeller extraction.

	Pre-press Solvent Extraction	Mechanical Expeller Extraction- a
	Proximate Analysis, (%)	Proximate Analysis, (%)
Dry Matter	89.20	96.96
	------------------Dry Matter Basis----	----------------------
Crude Protein	28.8	28.13
Ether Extract (lipid or fat)	.80	5.00-a
Crude Fiber	24.40	32.74
Ash	6.66	7.17
Van Soest Fiber Components, (%)
Acid Detergent Fiber	30.30	42.53
Neutral Detergent Fiber	38.70	46.33
Mineral Content, (%)
Calcium	1.10	1.15
Phosphorous	.90	.96
Potassium	1.07	1.14
Glucosinolate Content, (umoles/gram) allyl,	1.3	.7
3- butenyl	1.0	.6
2- hydroxy- 3- butenyl	192.6	82.9
2- hydroxy- 4- pentenyl	.9	.2
4- pentenyl	1.1	-
4- hydroxybenzyl	-	-
4- hydroxy- 3- methylindolyl	8.6	1.1

^a Nutrient values adjusted to 5% residual oil content from test crush samples