L. D. Campbell

The effects of protease and carbohydrase supplementation on the nutritive value of canola meal for poultry: In vitro and in vivo studies

Abstract An in vitro incubation system was used to assess a variety of enzyme preparations regarding activities toward protein and carbohydrate components in canola meal with the objective of identifying those preparations that possessed potential for improvement of the nutritive value of canola meal. Promising preparations were evaluated further in 2-week growth trials utilizing 4-day-old broiler chickens. Enhanced protein hydrolysis was demonstrated for several of the protease enzyme preparations studied in the in vitro incubation system. Protein hydrolysis was most effective when either pancreatin or pronase were included in the incubation medium along with the protease enzyme and for the most effective protease preparations values for percent of total protein hydrolyzed exceeded those for pancreatin or pronase acting alone. The most effective protease preparation also resulted in improved broiler chick growth performance when added to semipurified canola meal diets. While some carbohydrase enzyme preparations were shown to be effective in the in vitro test of cell wall polysaccharide solubilization, only a trend toward improved growth performance was noted when broiler chickens were fed semipurified canola meal diets containing these enzyme preparations. A synergistic response in growth of young (4–11 days of age) broiler chickens was noted when phytase, carbohydrase and protease enzymes were added to a wheat/canola meal based diet deficient in available phosphorus.

The use of enzyme technology for improved energy utilization from full-fat oilseeds. Part I: canola seed.

The effect of carbohydrase enzyme supplementation on energy utilization from full-fat canola seed was investigated in a TMEn assay with adult roosters and in a nutrient digestibility and growth performance study with broiler chickens. In the TMEn assay, enzyme preparations C (cellulase, 340 U/g), XG (xylanase, 63,600 U/g and glucanase, 48,300 U/g), P (pectinase, 10,000 U/g), and MC (mannanase, 10,900 U/g and cellulase, 600 U/ g), alone and in combination (C + P, C + XG, C + MC, P + XG, P + MC, XG + MC, C + P + XG, C + P + MC, and C + P + XG + MC), were evaluated at an inclusion level of 0.1%. On average, hammer-milled canola seed with a TMEn content of 3,642 kcal/kg showed an increase (P < 0.05) to 4,783 kcal/kg following supplementation with the enzyme blends C + P + XG, C + P + MC, and C + P + XG + MC. A similar pattern of increase (P < 0.05) in fat (80.4 vs. 63.5%) and nonstarch polysaccharide (NSP; 20.4 vs. 4.4%) digestibilities was observed. Enzyme combination C + P + XG was further evaluated in a 2-wk (5- to 18-d) trial with broiler chickens fed isonitrogenous and isoenergetic corn and soybean meal-based diets containing canola seed (15%), the corresponding canola meal (8.85%) plus canola oil (6.15%) mixture, or canola seed (15%) supplemented with 3 different levels (0.002, 0.01, or 0.05%) of the enzyme. Poorer (P < 0.05) feed:gain (1.412 vs. 1.344), lower (P < 0.05) total tract DM (65.9 vs. 70.7%) and fat (69.6 vs. 88.0%) digestibilities, lower AMEn content (2,963 vs. 3,200 kcal/kg), and lower ileal fat (65.6 vs. 85.6%) and protein (75.6 vs. 81.2%) digestibilities were observed for the canola seed diet compared with the canola meal plus canola oil diet. Enzyme supplementation of the canola seed diet resulted in an improvement (P < 0.05) in feed:gain; total tract DM, fat, and NSP digestibilities; AMEn content; and ileal fat digestibility. Although the enzyme effect on ileal and total tract fat digestibilities was significant at both high and medium inclusion levels, other parameters showed the significant improvement only when the highest inclusion rate of enzyme was used. These data support the need for carbohydrase enzyme supplements in poultry diets containing full-fat canola seed.

Wheat by-products in poultry nutrition. Part I. Chemical and nutritive composition of wheat screenings, bakery by-products and wheat mill run

A study was conducted to investigate the variability in chemical and nutritive composition of wheat screenings, bakery by-products and wheat mill run used by the feed industry in Canada. On average, and in comparison to wheat (as-fed basis), the wheat screenings (16 samples) contained less starch (457 vs. 560 g kg-1; P 0.05), phytate phosphorus (2.4 vs. 3.0 g kg-1; P > 0.05), and higher levels of protein (151 vs. 126 g kg-1; P < 0.0001), fat (66 vs. 12 g kg-1; P < 0.0001) and non-starch polysaccharides (NSP) (100 vs. 91 g kg-1; P < 0.01). A negative relationship (P < 0.0001) between starch and fat contents of the wheat screenings samples was noted indicating that a decrease in starch content of 20 g kg-1 would result in an increase in fat content by approximately 9 g kg-1. This inverse relationship should result in the maintenance of a relatively high content of available energy in...

Microbiological Decontamination of Poultry Feed—Evaluation of Steam Conditioners

The microbial decontamination of chicken feed, obtained from a commercial pellet mill, was evaluated using a direct-fired steam conditioner (DFSC ; APC System®). The standard plate count of the feeds before (mash) and after (pellets) conditioning ranged from 65 x 10 4 to 83 x 10 5 colony forming units (CFU) g -1 and from 91 x 10 1 to 92 x 10 3 CFU g -1 , respectively. The incidence of Escherichia coli, Salmonella and Listeria in the feeds before conditioning was 61.7, 8.3 and 27.1%, respectively. Following conditioning these levels were reduced to 1.7, 1.7 and 0%, respectively. Species of Listeria and Salmonella identified included L. monocytogenes, L. innocua and S. agona, S. ohio, S. heidelberg, S. senftenberg, S. tallahasse and S. braenderup, respectively. Compared with a conventional, indirect-fired boiler-generated-steam conditioner (IFSC) the direct-fired steam conditioner proved superior in regards to pathogen decontamination ; no E. coli, Salmonella or Listeria were recovered from mash lots positive for these microorganisms. However, with the IFSC system, both E. coli and L monocytogenes were recovered at levels of 11.1 and 5.6%, respectively.

Wheat by-products in poultry nutrition. Part II. Nutritive value of wheat screenings, bakery by-products and wheat mill run and their improved utilization by enzyme supplementation

A series of experiments was conducted to determine the nutritive value of wheat screenings, bakery by-products and wheat mill run used by the feed industry in Canada and to investigate the effect of enzyme supplementation on available energy content, nutrient digestibility and broiler chicken growth performance. Broiler chicken performance (2-wk growth trial) was compared using a wheat/soybean meal-based control diet and diets substituted with wheat by-products (wheat screenings, 200 g kg-1; bakery by-products or mill run, 100 g kg-1). In addition, diets containing one sample of each of the by-products were fed to broiler chickens with enzyme supplementation (Superzyme W®). Chicken performance was not affected by dietary substitution of wheat by-products for wheat as values for control, wheat screenings (three samples), bakery by-products (two samples) and mill run (one sample) were similar for body weight gain (514, 520, 515, 500 g bird-1) and for feed to gain ratio (1.52, 1.52, 1.52, 1.50), respectively...