Evaluation of Canola Meal Arising from the Processing of Canola Screenings

Date: September 4, 1998
Term: 2 years
Status: Completed
Researchers: Dr. Tim McAllister, K. Stanford, Agriculture & Agri-Food Canada; J.D. Popp, Alberta Agriculture; S. Pylot, Supertech Feeds; J.J. McKinnon, University of Saskatchewan
SaskCanola Investment: n/a
Total Project Cost: n/a
Funding Partners: Agriculture & Agri-Food Canada Matching Investment Initiative

Project Summary

In western Canada, one of the more widely available by-product livestock feeds is canola screenings (CS). Researchers at Agriculture and Agri-Food Canada in Lethbridge initiated a two-year study in 1997 to determine the feed value of commercial canola screenings in feeding trials with lambs, calves and finishing cattle. The results showed that in feeder lamb diets, incorporation of up to 45% CS would be cost effective, when CS was valued at 86% of the cost of barley. Canola screenings can be used as an economical substitute for hay in creep feeds and silage in feedlot finishing diets. Levels of CS in finishing diets should be restricted to 50% or less of the complete diet. Canola screenings would be a viable alternative during times of silage shortages or insufficient land base for production, and can significantly lower feed costs if nutrient quality and consistency can be ensured.

Due to fluctuations in the value of cereal grains and other traditional feed ingredients, low-cost byproducts could become increasingly important feeds if Canadian livestock are to remain globally competitive. In western Canada, one of the more widely available by-product feeds is canola screenings (CS), which are commonly classified as either “fines” or “coarse screenings” as determined by their respective contents of crude protein (CP) and crude fat. Studies evaluating coarse canola screenings for ruminant diets have been limited. Generally, CS have been priced at approximately 85 to 87% the cost of barley, so substituting CS into ruminant diets could be economically advantageous, provided that they do not impair animal performance or carcass quality.

Researchers at Agriculture and Agri-Food Canada in Lethbridge initiated a two-year study in 1997 to determine the feed value of commercial canola screenings in feeding trials with lambs, calves and finishing cattle. Coarse canola screenings were obtained from a commercial canola crushing plant, which included 60% canola (whole seed, broken seed, immature seed), with the remainder weed seeds (25%) and chaff/dust (15%).

Lamb Feedlot Experiment

The objectives of the lamb feedlot experiment were to: compare the apparent digestibilities of dry matter (DM), organic matter (OM), acid detergent fibre (ADF), neutral detergent fibre (NDF) and nitrogen (N) in diets containing varying levels of CS against those of a standard alfalfa–barley diet for rapidly growing feedlot lambs; to determine if lamb fat composition is altered by adding CS to diets; and to estimate the economic feasibility of replacing barley with CS in diets for rapidly growing feedlot lambs. Commercial coarse canola screenings (CS) were substituted for barley grain, and the resulting experimental diets (0, 20, 45, 70 and 95% CS, as-fed) were evaluated in feedlot lambs. In a digestibility study, 0, 45 and 95% CS diets were evaluated using Romanov x Suffolk lambs. The control diet (0% CS) contained 75% barley and 20% alfalfa (as a protein/fibre source).

The results of the experiments showed that dietary crude protein (CP) increased with inclusion of CS and was lowest for control and 20% CS diets (13%) and highest for the 95% CS diet (14.4%). Digestibilities of dry matter (DM), organic matter (OM), neutral detergent fibre (NDF) and acid detergent fibre (ADF) were reduced in the 95% diet as compared with the control diet. Nitrogen retention by lambs was three times higher in the control group than in the 95% CS group. Growth and feed conversion efficiency in feedlot lambs were linearly reduced with increasing dietary CS, but so was saturation of carcass fat. Valuing CS at 86% of the cost of barley, incorporation of up to 45% CS in feeder lamb diets would be cost effective.

Creep Feed Experiment

Two groups of cow-calf pairs were put on pasture near Olds, Alberta, with one group of calves having access to creep feed consisting of 100% canola screenings and the other group with access to 75% canola screenings/25% barley grain (as-fed basis). The results of the experiment showed that supplementing the canola screenings creep feed with barley grain resulted in higher body weights of first-calf cows after 42 and 63 days on pasture. However, body condition scores and backfat thickness of cows did not differ between treatment groups. In cows whose calves had access to the 75:25 barley:canola screenings creep feed, conception rates tended to be higher and number of days pregnant greater. Increasing the energy content of canola screenings by including barley grain had little effect on overall calf gains, however, calves fed the 75:25 creep feed gained more in the first 42 days on pasture than those with access to the screenings only creep feed. Canola screenings were found to be a palatable creep feed for grazing calves. Conservation of forage through the use of creep feed may be especially valuable in situations where the pasture availability is a constraint to beef production.

Cattle Feedlot Experiment

Two experiments were conducted to determine the feeding value of canola screenings in combination with barley grain for beef steers. Four dietary treatments were used. These included canola screenings:barley grain ratios of 100:0; 75:25, 50:50, and 25:75 (as-fed basis). A barley grain/barley silage-based control diet was also fed for comparison purposes.

Overall the results showed that the inclusion level of canola screenings had no effect on dry matter (DM) intake. However, ADG and feed efficiency increased as the level of barley grain in the diet increased. Increasing the level of barley grain in the finishing diet decreased lean meat yield and increased carcass fat. Researchers concluded that canola screenings can be included as a source of fiber in barley-based diets. However, levels in excess of 500 g kg–1 reduced the performance of feedlot steers. High (75% and above) levels of canola screenings were also associated with the occurrence of bloat. Performance and cost of gain with 25% and 50% canola screenings in barley-based finishing diets were comparable to those calculated for 80:20 barley grain/barley silage diets, making canola screenings a viable alternative during times of silage shortages.

Scientific Publications

Pylot, S. J., McKinnon, J. J., McAllister, T. A., Mustafa, A. F., Popp, J. and Christensen, D. A. 2000. Canola screenings as a fiber source in barley-based feedlot diets: effects on rumen fermentation and performance of steers. Can. J. Anim. Sci. 80:161–168.

Stanford, K., Wallins, G. L., Smart, W. G. and McAllister, T. A. 2000. Effects of feeding canola screenings on apparent digestibility, growth performance and carcass characteristics of feedlot lambs. Can. J. Anim. Sci. 80: 355–362.

Full Report PDF: Evaluation of Canola Meal Arising from the Processing of Canola Screenings