Livestock production from grazing is an integrated measure of the quantity and quality of forage produced and consumed. Research was conducted over 6‐yr to assess the effects of four yearlong grazing treatments on cow‐calf production (382 cows Bos taurus) and economic returns under extensive rangeland conditions (4637 acres). Treatments were heavy (HC) and moderate (MC) stocked continuous (1‐pasture; 1‐herd), a moderate stocked 4‐pasture, 3‐herd deferred rotation (DR); and a very heavily stocked 16‐pasture, 1‐herd rotation (RG). Averaged across years, stocking rates were approximately 12, 16, 15, and 10 acres/cow‐year for the HC, MC, DR, and RG treatments, respectively. From 1982 through 1987, conception rates averaged 89, 93, 95, and 89%; weaned calf crops averaged 80, 83,86, and 80%; weaning weights averaged 579, 574, 593, and 550 lb; production/cow averaged 466, 467, 508, and 439 lb; production per acre averaged 40, 31,35, and 45 lb; and residual returns to land, management and profit averaged $60.81, $69.57, $93.12, and $62.72/cow and $5.35, $4.46, $6.47, and $6.63/acre for the HC, MC, CR, and RG treatments, respectively. Results show that stocking rate was the major factor affecting differences among grazing treatments in cow/calf production and economic returns and that, as stocking rate was increased, production stability decreased.

Application of high performance anion chromatographij (HPAEC) to distillers worts was able to resolve a series of individual fractions (A, B, C, D, E and F) which eluted between a(l-4) linear dextrins (DP4-7) and which were ubiquitous in worts. Their positions in the chromatogram and their behaviour suggested that they might be aCl-6) branched dextrins. Two of these fractions (C and D) were purified and shown to be a(l-6) branched dextrins by treatment with an a(l-6) debranching enzyme (pullulanase). Further characterisation by HPAEC and Matrix Assisted Desorption lonisation/Time of Flight (MALD1-TOF) mass spectrometry revealed that the unknown fractions, C and D, were a(l-6) branched dextrins consisting of 6 and 7 glucose units respectively. Possible structures were suggested for these two fractions and it ivas shown that they were comprised of maltosyl and maltotriosyl branches attached by a(l-6) links to maltotriose, maltotetraose and maltopentaose. The behaviour of these dextrins was studied in the context of the Scotch whisky process under both laboratory and production conditions and they were found to be important substrates for the debranching enzyme, limit dextrinase, during fermentation. The study of these dextrins provided a useful tool for monitoring the effects of enzymes (a-, p-amylase and limit dextrinase) in the Scotch malt whisky production process.

Limit dextrinase, is an important enzyme in the hydrolysis of starch from cereals to fermentable sugars. Work is described which demonstrates the importance of this enzyme in the production of Scotch ivhisky. Tlie study considers the occurrence, survival and action of limit dextrinase (total and free) during fermentation in malt and grain distilleries. The results of both laboratory and distillery studies revealed that limit dextrinase can survive the conditions encountered during mashing and is not only present in the fermenter but its activity can increase duringfermentation.Tltis observation has important implications for the production of Scotch whisky, since the fermentation substrate (wash) is not boiled, the enzyme is therefore available to degrade dextrins into fermentable sugars, and can potentially increase the yield of alcohol.