GRAIN SCREENINGS AS A DIETARY COMPONENT FOR PIGS AND SHEEP. I. BOTANICAL AND CHEMICAL COMPOSITION

Abstract

Screenings were collected from grain elevators in the port of Vancouver and from a rapeseed processing plant in Alberta. From a total of 251 samples consisting of No. 1 feed screenings, uncleaned screenings, refuse screenings, rapeseed screenings and mixed feed oats, samples which appeared to be representative of the range were selected — 36 for botanical analysis and 94 for chemical analysis. The No. 1 feed screenings consisted of over 90% wheat (Triticum vulgare) and wild buckwheat (Polygonum convolvulus), with a mean protein content of 14.8%. The composition of uncleaned screenings was highly variable, but approximated poorly cleaned No. 1 screenings. Refuse screenings could be divided botanically only into chaff, dust, grain and weed seeds, with an average total chaff plus dust content of 70%. Mean levels of crude protein and acid detergent fiber were 11.7% and 33.0%, respectively. Rapeseed screenings contained an average of 15.6% rapeseed, with the remainder mostly weed seeds, the major ones being stinkweed (Thlaspi arvense; mean 19%) and lamb's-quarters (Chenopodium album; mean 18%). Average content of crude protein, acid detergent fiber and ether extract was 19.6, 28.0 and 22.5%, respectively. Mixed feed oats were essentially wild oats (Avena fatua). Average levels of crude protein and acid detergent fiber were 13.4 and 22.5%, respectively. Key words: Grain, wheat, barley, oats, rapeseed, screenings