B. A. Slominski

Recent advances in research on enzymes for poultry diets

Exogenous enzymes have been used extensively in the diets of poultry to improve productive performance. Further research, however, is needed to evaluate the efficacy of enzyme use and for the expansion of the use of enzymes to accommodate the wide array of dietary constituents used in poultry feeding programs. The use of effective phytase preparations to improve bird performance and to reduce environmental P pollution has shown less than optimum results, partly due to the potential negative effects of nontargeted dietary fiber components and to confounding influence of inadequate knowledge of accurate P requirements and the tendency for the use of excessive safety margins in diet formulation. Targeting specific nonstarch polysaccharides (NSP) of wheat, barley, or rye with enzyme preparations has proven effective for diets based on these cereals but not for corn- and soybean meal-based diets, primarily due to the differences in constituent NSP. The increased use of whole flaxseed in poultry diets represents an additional research area for effective enzyme development to alleviate potential negative effects of constituent NSP components. Such challenges of the enzyme development process and their outcomes are presented in this publication.

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.

Growth performance and nutrient digestibility in pigs fed wheat distillers dried grains with solubles-based diets supplemented with a multicarbohydrase enzyme.

The objective was to investigate the effect of supplementing a wheat distillers dried grains with solubles (wheat DDGS)-based diet with carbohydrase enzyme blends on growth performance and nutrient digestibilities in growing and finishing pigs. In Exp. 1, 48 pigs with a BW of 36.5 +/- 1.03 kg (mean +/- SD) were randomly assigned to 24 pens (2 pigs per pen) on the basis of sex and BW, and pigs were randomly allocated to experimental diets (6 pens per diet). Dietary treatments were a positive control (PC) formulated to meet or exceed NRC (1998) nutrient requirements and a negative control (NC) with DE and Lys reduced by 4 and 5%, respectively, from the PC diet and fed without or with an enzyme blend at 2 levels. Level 1 enzyme supplied 2,600 U of xylanase, 1,200 U of beta-glucanase, and 1,300 U of cellulase per kg of diet; level 2 enzyme provided twice the activities for each enzyme in level 1 per kilogram of diet. Chromic oxide was used as an indigestible marker. Pigs fed the NC diet had less (P < 0.05) ADG than those fed the PC diet. Supplementing the NC diet with enzyme blends linearly increased ADG (P < 0.01). The ADFI was not affected by dietary treatment. The PC diet had greater (P = 0.04) G:F compared with the NC diet, but not the enzyme-supplemented diets. Pigs fed the PC diet had greater (P < 0.01) digestibilities of N, GE, and ether extract compared with those fed the NC diet. Addition of level 2 enzyme to the NC diet improved (P < 0.05) digestibilities of DM, N, GE, and ether extract to levels similar (P > 0.05) to those fed the PC diet. In Exp. 2, 4 ileal cannulated barrows (80.8 kg of BW; SD = 0.65) were allotted to 4 diets in a 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. Experimental diets contained 15 or 30% wheat DDGS and were fed without or with enzyme addition. The enzyme supplement supplied 2,200 U of xylanase, 1,100 U of beta-glucanase, and 1,200 U of cellulase per kg of diet. Apparent ileal digestibilities (AID) of DM, OM, and energy in enzyme-supplemented diets were greater (P < 0.05) than in unsupplemented diets. There was an interaction effect (P < 0.05) of wheat DDGS inclusion level and enzyme supplementation on AID of DM and Ser. Enzyme supplementation improved (P < 0.05) AID of DM in the diet with 30% wheat DDGS but not 15% wheat DDGS. The results shows that multienzyme supplementation of 30% wheat DDGS-based diet improved growth performance and apparent total tract digestibility of DM, N, GE, and crude fiber in growing pigs and AID of nutrients in finishing pigs.

Effects of diet type and enzyme addition on growth performance and gut health of broiler chickens during subclinical Clostridium perfringens challenge

The effects of diet type (corn- vs. wheat-based) and multicarbohydrase addition on growth performance, digesta pH and viscosity, intestinal populations of Clostridium perfringens and lactic acid bacteria, and gut lesion score (from 0 to 4, where 0 = no gross lesions, 4 = severe extensive necrosis) of broiler chickens during oral challenge with C. perfringens (none or 10(8) cfu/bird on d 13) were studied in a 39-d experiment. A total of 1,216 male Ross-308 chickens was assigned to 8 dietary treatments in a randomized complete block design providing 8 replicate pens per treatment. Diets were formulated to meet the NRC protein requirement but were suboptimal in energy level. When compared with birds fed corn-based diets, chickens fed wheat-based diets had inferior (P < 0.01) final BW (2.49 vs. 2.59 kg) and feed conversion ratio (FCR; 1.83 vs. 1.78). Pathogen challenge significantly (P < 0.05) impaired growth performance and increased C. perfringens numbers and average lesion score. Increased (P < 0.01) C. perfringens counts (2.4 vs. 1.5 log(10) cfu/g of digesta) and intestinal lesion score (0.9 vs. 0.4) were observed for challenged birds fed wheat-based diets. No difference in digesta pH and lactic acid bacteria numbers were found among the treatments. Enzyme addition to both the corn- and wheat-based diets increased bird final BW (2.57 vs. 2.51 kg; P < 0.01), decreased overall FCR (1.78 vs. 1.83; P < 0.01), and, in those consuming wheat-based diets, reduced digesta viscosity (from 4.1 to 2.7 mPa.s; P < 0.01). Enzyme supplementation assisted the challenged birds in maintaining their optimal growth performance by improving (P < 0.05) average daily gain (59.5 vs. 56.9 g) in those consuming corn-based diets and FCR (1.83 vs. 1.90) in those consuming wheat-based diets to values similar to those observed in control birds (59.7 g/d and 1.84, respectively). In conclusion, enzyme addition improved growth performance and mitigated the negative effects of C. perfringens challenge.

The Effect of Enzyme Supplementation on Egg Production Parameters and Omega-3 Fatty Acid Deposition in Laying Hens Fed Flaxseed and Canola Seed

An experiment was conducted to investigate the effects of a multicarbohydrase enzyme on egg production parameters, nutrient digestibility, and egg fatty acid composition in Hy-Line CV-20 laying hens (39 to 63 wk of age) fed diets containing 150 g/kg of diet of canola seed, flaxseed, or Linpro (flaxseed:peas, 1:1 wt/wt). The diet effect on each parameter was also evaluated. Hens consuming the canola seed and Linpro diets had greater egg production, lower feed consumption, and therefore better feed conversion than those fed the flaxseed diets. Enzyme supplementation significantly increased (P < 0.01) egg production (from 78.0 to 80.9%) and improved (P < 0.001) feed conversion ratio (from 2.15 to 2.03) in hens fed flaxseed. Hens fed the canola seed and Linpro diets produced eggs with greater egg specific gravity than those from birds consuming flaxseed. Enzyme supplementation significantly increased egg specific gravity in hens fed flaxseed (from 1.0773 to 1.0800, P < 0.01) in phase I of the experiment. There was no effect of diet on fat digestibility, and similar fat digestibility values with enzyme supplementation were observed for canola seed (92.1 vs. 96.7%) and flaxseed (87.4 vs. 92.4%). Eggs produced by hens fed flaxseed had the greatest n-3 fatty acid content (562 mg/60 g of egg) when compared with those from hens consuming canola seed (207 mg/60 g of egg) or Linpro (427 mg/60 g of egg). Enzyme supplementation increased the egg n-3 content for the flaxseed diet (from 546 to 578 mg/60 g of egg; P = 0.01) and for the Linpro diet (from 415 to 438 mg/60 g of egg; P = 0.05). In addition, enzyme addition increased the egg docosahexaenoic acid content from 91.8 to 101.9 mg/60 g of egg (P < 0.01) and from 89.4 to 96.8 mg/60 g of egg (P = 0.01) for the flaxseed and Linpro diets, respectively. When compared with canola seed, long-term feeding of flaxseed to laying hens resulted in reduced egg production and eggshell quality. Enzyme supplementation had positive effects on feed utilization, eggshell quality, and n-3 fatty acid deposition in the egg.

Growth performance and nutrient utilization of broiler chickens fed diets supplemented with phytase alone or in combination with citric acid and multicarbohydrase

An experiment was conducted to determine the effect of supplementing a corn-soybean meal-based diet with phytase alone or in combination with citric acid (CA) or multicarbohydrase, a preparation containing nonstarch polysaccharide-degrading enzymes, or both, on growth performance, nutrient utilization, and bone mineralization. A total of 360 one-day-old broiler chicks were assigned to 6 dietary treatments, consisting of 12 pens of 5 birds each, and were fed experimental diets from 1 to 21 d of age. The diets included a positive control (0.46% nonphytate P; 1.1% Ca) and a negative control (NC; 0.26% nonphytate P; 0.89% Ca) without or with phytase (600 U/kg) alone, phytase plus CA (5 g/kg), phytase plus multicarbohydrase (Superzyme OM; 0.6 g/kg), or phytase (Ronozyme P-CT) plus CA and multicarbohydrase. Birds fed the positive control diet had higher (P<0.05) BW gain (764 vs. 594 g/21 d) and tibia ash content (50.0 vs. 38.3%) than those fed the NC diet. Phytase improved (P<0.05) BW gain (632 g/21 d), which increased further (P<0.05) to 673 g/21 d for the phytase plus multicarbohydrase diet. In contrast to phytase alone, phytase plus multicarbohydrase supplementation improved (P<0.05) feed conversion ratio of the NC diet from 1.37 to 1.32. Tibia ash content for the NC diet increased (P<0.05) from 38.3 to 42.4% due to phytase addition. Phytase improved (P<0.05) ileal digestibility of P from 29.5 to 43%, and the addition of CA or multicarbohydrase, or both, to a phytase-supplemented diet further increased (P<0.05) P digestibility to 51.5, 53.4, and 54.3%, respectively. Phytase addition improved (P<0.05) diet AMEn content from 2,959 to 3,068 kcal/kg, which tended (P<0.06) to increase further with CA (3,150 kcal/kg) or multicarbohydrase (3,142 kcal/kg) addition. No beneficial interactions were detected between CA and multicarbohydrase for all response criteria measured. Results show that addition of multicarbohydrase to the phytase-supplemented broiler diets improved nutrient utilization and growth performance.

The effect of different dietary levels of rapeseed meal on growth performance, carcass traits, and meat quality in turkeys

The objective of this study was to determine the effect of different dietary levels of low-glucosinolate rapeseed meal (RSM) on growth performance, blood thyroid hormone concentration, carcass traits, and chemical composition, physicochemical properties, and fatty acid profile of breast meat in growing turkeys. The experiment lasted for 21 wk. Large White BIG-6 turkeys were fed isoenergetic and isonitrogenous diets containing 0, 60, 120, and 180 g/kg of RSM. Each experimental group was comprised of 7 replicates/pen of 28 birds each. There was no effect of graded levels of RSM on final BW. An increase in the inclusion rate of RSM was followed by a linear increase in feed conversion ratio, which was significantly higher (P < 0.05) in the group fed 180 g/kg of RSM. The blood levels of free triiodothyronine decreased significantly (P < 0.05) regardless of the dietary level of RSM. No significant changes in the carcass dressing percentage or the meat fat content were observed. Significant differences were found in the fatty acid composition and physicochemical properties of breast meat. The concentrations of margaroleic acid and saturated fatty acids, including myristic and palmitic acid, in meat from male turkeys fed 120 and 180 g/kg of RSM decreased linearly; whereas the levels of oleic acid and polyunsaturated fatty acids, including linoleic and linolenic acid (an n-3 fatty acid), increased linearly. An increase in RSM content of the diets was accompanied by the unfavorable changes in selected functional properties of meat, including a significant increase in drip loss in groups fed 120 g/kg of RSM (from 1.85 to 2.38%) and 180 g/kg of RSM (from 1.85 to 3.02%) and a decrease in Warner-Bratzler shear force values in turkeys fed 180 g/kg of RSM (from 19.1 to 15.8 N). The results suggest that the quality of turkey meat could be affected by impaired triiodothyronine secretion caused by dietary RSM.

The effect of diets containing soybean meal, soybean protein concentrate, and soybean protein isolate of different oligosaccharide content on growth performance and gut function of young turkeys

An experiment was conducted to investigate the effects of diets containing soybean meal (SBM), soybean protein concentrate (SPC), and soybean protein isolate (SPI) on growth performance and gut function of the young turkey. A total of 812 one-day-old male turkey poults were randomly assigned to 4 dietary treatments, with 7 pens per treatment and 29 birds per pen. The 4 experimental diets contained SBM, SBM-SPC, SPC, and SPI and were fed throughout the two 4-wk experimental periods. In each period, the diets were isonitrogenous and isocaloric and contained similar amounts of total and water-soluble nonstarch polysaccharides. The content of oligosaccharides differed among the diets and averaged 2.4, 1.9, 0.9, and 0.1% for SBM, SBM-SPC, SPC, and SPI, respectively. When compared with SBM, birds consuming the SBM-SPC and SPC diets had higher (P<0.05) final BW (4.32 vs. 4.45 and 4.46 kg, respectively). Incorporation of SPI as a substitute for SBM resulted in improved (P<0.05) feed utilization (from 1.76 to 1.67) but did not affect the final BW. Significant changes in cecal concentrations of short-chain fatty acids were observed and averaged 130, 103, and 89 micromol/g of digesta for the SBM, SBM-SPC, and SPC diets, respectively. This coincided with the proportional decrease in dietary oligosaccharide content (from 2.4 to 0.9%) and was further substantiated by a significant decrease in ileum weights. Feeding the SPI diet resulted in the lowest ileal and cecal tissue weights as well as the lowest cecal short-chain fatty acids concentration. There was no effect of diet on digesta pH, viscosity, and mucosal sucrase and maltase activities. Bacterial beta-glucuronidase activity was decreased (P=0.08) in the cecum (from 0.98 to 0.60 U/g) with decreased dietary oligosaccharide content. In conclusion, partial or almost complete substitution of SBM with SPC suppressed the fermentation processes in the ceca but enhanced the growth rate. Substitution of SBM with SPI significantly improved feed utilization but decreased BW of 4-wk-old turkeys with no effect on growth rate of older 8-wk-old birds.

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...