Adding Roxazyme to Wheat Diets of Chicken and Turkey Broilers

019% Applied Poultry Science, loc

ADDING ROXAZYME TO WHEAT DIETSOF CHICKEN AND TURKEY BROILERS

Primary Audience: Nutritionists, Feed Manufacturers, Broiler and Turkey Integrators

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We conducted two experiments with turkey broiler hens and one experiment with chicken broilers to note the effect of adding the enzyme Roxazyme to diets containing wheat as the major cereal source. In Experiment 1, turkey hens were significantly(P< .Ol) heavier at 56 days when fed Roxazyme (3782 vs. 3113 g) and this effect carried through to market age of 72 days (6436vs. 5774 g). Feed intake increased significantly, although feed efficiency, mortality, and litter score were not affected. In a second study with turkey hens, enzyme had no effect on performance wben fed from only 28-84 days. Male broiler chickens fed a wheat-based diet were also heavier at 28 days when fed Roxazyme (1352 vs. 1286 g), although this effect declined with age. At 42 days, however, Roxazyme affected carcass weight significantly (1942 vs. 1848g), and this was associated with more abdominal fat (41.9 YS. 33.4 g) and more breast meat (421 vs. 397 g). For both broilers and turkeys, the effects of Roxazyme are most pronounced in the starter period.

Key words: Broiler, enzyme, wheat, turkey 1996 J. Appl. Poultry Res. 5167-172

and because of their molecular structure the DESCRIPTION OF PROBLEM resultant solution is very viscous. Research Wheat sometimes appears to be an attractive feed ingredient for chickens and turkeys. Unlike corn, however, wheat varies considerably in chemical composition, which probabIy reflects varietal differences and variation in growing conditions. The presence of so-called non-starch polysaccharides, and in particular arabinoxylans gives greatest cause for concern, because these substances are not well digested, especially by young birds. Unabsorbed arabinoxylans are soluble in water, 1

To whom correspondence should be addressed

indicates that such viscous digesta interfere with digestion and absorption of most nutrients; Choct and Annison [l] attribute the poor digestibility of wheat to their presence. In addition to causing reduced digestibility, viscous digesta can cause problems with excreta consistency, which leads to increased potential for foot pad and general skin lesions, especially for older market weight birds that rest on the litter more frequently.

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STEVE LEESON' and LINDA J. CASTON Deparhnent of Animal and Poultry Science, University of Guelph, Guelph, ON NlG 2W1, Canada Phone: (519) 8244120, Ext. 3681 F M : (519) 836-9873 DOUG YUNGBLUT Homann-La Roche, Ltd., 2455 Meadowpine Blvd., Mississauga, ON LSN 6L7, Canada

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feed and water and received continuous lighting. AU birds were weghed and feed intake measured at 28,56, and 77 days of age. STATISTICAL ANALYSIS The experiment was arranged as a completely randomized design in which pen was considered the experimental unit. There were two levels of treatment classification,the control diet and the Roxazyme diet. Data were analyzed by a T-test procedure appropriate to two levels of treatment classification. The response variables considered were body weight, body weight gain, feed intake, feed intake:body weight gain, and mortality.

MATERIALS AND METHODSEXPERIMENT 2 Six hundred forty-four commercial strain

We conducted two trials with turkeys and one trial with broiler chickens. In one turkey trial and the broiler trial, Roxazymewas added to both high-energy and low-energy diets. Because there was no significant (P > .OS) interaction between enzyme and diet energy level, and because the effect of energy level per se is well documented, we have presented only the main effect of enzyme treatment. The enzyme used in all studies was Roxazyme (Hoffman La Roche, Mississauga, ON L5N 6L7, Canada) which contains 18,000 units j3 gluconase and 8,000 units cellulase activity and 26,OOO units xylanase per gram. In all studies, Canadian hard red spring wheat was used in formulation, although different batches were used for each of the three experiments. EXPERIMENT 1 Three hundred twenty day-old Nicholas female poults were wing-banded and allocated at random to pens maintained in a room with environmental control. Each 1.45 x 5.7 rn pen contained 20 poults. Birds were fed starter diets to 28 days, grower diets to 56 days, and finisher diets to 77 days. Table 1 shows the composition of the wheat-based starter diet. Levels of crude protein were 28, 25, and 22%, respectively, while ME was formulated to 2900, 3050, and 3200 kcal/kg, respectively, for the three phases. Each diet was formulated to contain Roxazyme at 200 g/ton, or no Roxazyme, with each treatment represented by eight replicate pens of turkeys. Starter diets were crumbled, while grower and finisher diets were pelleted. Birds had free access to

female turkey broilers were weighed, wingbanded, and allocated at random to one of four treatment groups replicated four times, 40 birds per replicate. Replicates were randomized over 16 floor pens each measuring 1.8 x 2.4 m. Thrkey poults were maintained at a brooding temperature of 32°C and 24 hr of light for 5 days; environmental temperature was then gradually reduced, in keeping with normal brooding practice. The turkeys were reared on a regular turkey starter diet to 28 days of age, and at this time all birds were weighed and the pen average weight recorded. Feed intake was also measured and diet treatments were applied at this time. Treatments involved single-stage diets from 28-84 days, with or without Roxazyme at 200 @ton.Table 1 shows the composition of the diets at 28 days. All diets contained exactly 65% wheat, and this was the only cereal source. Diets were formulated to 23% CF', 0.65% methionine, 1.53% lysine, and either 3136 or 3018 kcal ME/kg. Substitution of fat for oat hulls produced differences in energy level. Birds had free access to feed and water throughout the trial, which lasted to 84 days of age. Birds and feed were weighed at 56 and 84 days of age. STATISTICALANALYSIS The trial was arranged as a completely randomized design; pen was considered the experimental unit and data analyzed as such. The data were considered for statistical analysis by a hvo-factor factorial arrangement in which the main effects were presence or absence of Roxazyme in the diet and high or low

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These problems can be resolved by limiting the quantity of wheat in the diet, or possibly by adding synthetic exogenous enzymes to the feed that includes wheat. Most work with exogenous enzymes has been carried out with chickens fed barley or rye. There is little information on the effectiveness of enzymes for chickens fed wheat diets, and virtually no information on response of turkeys to such treatments. We conducted three trials with turkey and chicken broilers to determine the effect of a commercial enzyme, Roxazyme, on performance and carcass characteristics when diets contained wheat as the only source, or a major source, of cereal.

ENZYMES FOR WHEAT DIETS

Research Report 169

LEESON el al.

INGREDIENT

EXPERIMENT 1

EXPERIMENT 2

EXPERIMENT 3

66.00 -

46.0

-

-

Corn

-

-

-

23

23

3136 or 3018

3166 or 3015

Crude protein, 70 Metabolizable energy, kcalkg Calcium, % Amiable phosphorus, % Methionine, % Lysine, 70

28.13 2900

65.00

1.40

1.OO

0.90

0.66 0.65 1.75

0.53 0.65

0.43 0.65

153

1.54

diet energy. Interaction of enzyme and diet energy level were also examined, although as previously discussed, only the main effect of enzyme was significant and only this is presented. Since treatment was applied at day 28 of the trial, %-day body weight was used as a covariate for all response variables. Response variables resulting in a significant F-test were further examined using Duncan's Multiple Range Test. EXPERIMENT 3 Seven hundred twenty commercial strain male broiler chicks were weighed, wingbanded, and allocated at random to one of four treatment groups replicated six times, 30 chicks per replicate. Replicates were randomized over 24 floor pens each measuring

1.8 x 2.4 m. Chicks were maintained at a brooding temperature of 32°C and 24 hr light for 5 days. Environmental temperature was then gradually reduced according to standard brooding practice. Birds were fed single-stage diets through to 42 days of age. All diets contained 65.88% wheat, and this was the only cereal used (Table 1). Diets contained 23% CP, 0.65% methionine, 1.54% lysine, and either 3166 or 3015 kcal ME/kg. Substitution of fat for oat hulls produced differences in energy level. Birds were fed dietswith or without Roxazyme at 200 g/ton. Birds and feed were weighed at 28 and 42 days of age. On day 43, eight birds were randomly selected from each pen and processed at the Universityplant. During evisceration, the abdominal fat pad and the breast

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Wheat Barley

ENZYMES FOR WHEAT DIETS

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muscles (pectoralis and supracoracoideus) were removed and weighed.

RESULTS AND DISCUSSION Roxazyme had a dramatic positive effect on the growth rate of turkeys to 72 days, especially in the 28-56 day period (Table 2, Experiment 1). This increased growth rate was associated with increased feed intake (Pe.01) such that there was no difference in feed efficiency to 77 days (Table 2, Experiment 1). In the first trial, enzyme addition had no effect on mortality, which averaged 3.1% for both treatments, and

TABLE 2. Effect of Roxazyme on turkey broiler performance (Experiment 1)

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TABLE 3. Effect of Roxazvme on turkev broiler Derformance (Exoeriment 2)

TREATMENT

FEED INTAKE

BODY WEIGHT g

FEED:GAIN

glBird

56 Days

84 Days

28-56 Days

56-84 Days

28-84 Days

Control

3779

7436

4670

7818

1.95

Roxazyme

3844

7486

4621

'7772

1.93

8s

86

139

211

0.04

NS

NS

NS

SD

NSA *Non-simificant (P> .OS)

NS

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STATISTICAL ANALYSIS The data were considered for statistical analysis by a two-factor factorial arrangement in which the main effects of presence or absence of Roxazyme and high and low energy diet were examined, as well as their interaction. Only the main effect of Roxazyme was significant, so only this interaction is presented. Response variables analyzed were body weight, body weight gain, feed intake, feed intake:body weight gain, mortality, carcass weight, abdominal fat pad weight, breast meat yield, and the calculated values of breast meat yield as a percentage of carcass welght and abdominal fat pad weight as a percentage of carcass weight.

there was a minor non-si&icant (P > .OS) improvement in litter score when enzyme was used. In the second experiment (Table 3), the addition of Roxazyme had no signifcant (P>.O5) effect on any of the parameters measured, although there was an indication of slightly higher growth rate to 56 days. In the third experiment, which involved broiler chickens, Roxazyme again resulted in improved earlygrowth rate, with broilers some 5% heavier at 28 days (Table 4). Although there was only a non-significant (P > .05) increase in body weight at 42 days, this effect is evidently real: There was a highly sigmticant (P < .Ol) increase in carcass weight (Table 5) for broiler chickens fed Roxazyme. This 5% increase in carcass weight was associated with increased fat deposition (Table 5) as well as a 6% increase (P < .Ol) in breast meat yield. Performance of birds fed enzymes such as Roxazyme usually shows numerical improvement, but effects are not always statistically slgtllficant. This may result in part from variable composition of the wheat varieties used. It is expected that response would be greater in wheat samples with more arabinoxylans, because these are believed to be the cause of poorer digestibilityof wheat [l].For example, Brenes et al. [2] showed a 10% improvement in both weight gain and feed efficiency of young wheat-fed broilers given Roxazyme and

Research Report LEESON et al.

171

TREATMEW

BODY WEIGHT

FEED INTAKE

g

g/Bird

FJZED:GAIN

28 Days

42 Days

Control

12.36

2536

1888

2407

1.72

Roxazyme

1352

2590

1908

2361

1.68

100

137

0.09

NS

NS

NS

SD

36

**

102 NSA

0-28 Days

28-42 Days

0-42 Days

TREATMEm

CARCASS WEIGHT

ABDOMINAL FAT

BREAST WEIGHT

g

g

70Carcass

g

70Carcass

Control

1848

33.4

1.81

397

21.5

Roxazyme

1942

41.9

2.16

421

21.7

62 **

3.7 **

0.22 **

16 **

NSA

SD

I*Nowsignificant (P < .OS) **Significantdifference (P < .01)

attributed these substantial improvements to unusually high levels of arabinoxylans in wheat from a region with very dry growing conditions. Improvement in growth rate may not always occur, because Roxazyme is expected to improve the digestibility of the carbohydrate portion of wheat, and so energy level and hence feed efficiency are the characteristics most likely to change. When using high arabinoxylan wheat, or high p-glucan barley, enzymes may also improve growth rate due to the effect of the viscous digesta on digestibility of all nutrients, and not just the pentosans or arabinoxylans in question. Brenes et al. [3] showed no effect of Roxazyme on growth rate of young birds fed wheat, although there was a significant improvement in feed efficiency. Friesen et al. [4] also showed a 7% improvement in diet metabolizable energy when enzyme was used in a diet containing 70% wheat, and this resulted in a 9% improvement in feed efficiency. Few comparable reports exist on the effects of feeding Roxazyme or other comparable enzyme products to turkey broilers. In Experiment 1 a substantial improvement in body weight occurred in Roxazyme-fed birds during the 28-56 day period (Table 1).This

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major difference in weight gain was associated with increased feed intake, and there was no difference in mortality between treatment groups over this time period. In Experiment 2, however, control-fed birds were comparable in weight to Roxazyme-fed birds, and both groups had a similar weight to that of the 56 day birds in Experiment 1. As with the broiler turkeys in Experiment 1, the major effect of Roxazyme on growth of broiler chickens occurred in the earlier part of the growth period. Enzymes such as Roxazyme may therefore be more efficacious for young buds than for older birds. In fact, research indicates that for adult birds, some commercial enzyme preparations have negative effects on certain aspects of nutrient utilization [5]. There are few reports of the effects of enzymes on carcass characteristics of birds. The significant increase in 42 day carcass weight of broilers fed Roxazyme is likely a reflection of better growth rate, although the increase in proportional sue of the abdominal fat pad is an indirect indication of greater energy intake. Because feed intake was similar for birds in both treatments, a greater energy intake suggests that Roxazyme yields improvement in diet metabolizable energy.

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TABLE 5. Effect of Roxazyme on chicken broiler carcass characteristics (Experiment 3)

JAPR ENZYMES FOR WHEAT DIETS

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CONCLUSIONS AND APPLICATIONS 1. Turkey broilers show variable response to R o v e when fed wheat-based diets. The major response is with younger birds, apparently due to improved energy utilization. 2. Broiler chickens fed wheat-based diets respond well to Roxazyme, especially in early growth rate and improved carcass characteristics. 3. Roxazyrne seems most advantageous for younger wheat-fed birds.

REFERENCES AND NOTES

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4. Friesen, O.D., W. Guenter, RR Marquardt, and B.A. Rother, 1992. The effect of enzyme supplementation on the apparent metabolizable energy and nutrient digestibilhies of wheat, barley, oats, and Ge for the young broiler chick. poultry S& 71:171&1721. 5. Leeson, S. and J. Pro1995. Enzymes and barley metabolizable energy. J. Appl. Poultry Res. 3:6M8.

ACKNOWLEDGEMEW This work was supported by the Ontario Ministry of Agriculture, Food and Rural Affairs, Toronto, Ontario. Roxazyme was d o n a t e d by Hoffman-La Roche, Mississauga, Ontario.

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1. Choct, M. and G. Annison, 1992. The inhibition of nutrient digestion by wheat pentosans. Br. J. Nutr. 67123-132. Smith w-Guenter, and RR 2. Brenes, Marquardt, 1993. Effect of enzyme supplementation on the performance and digestive tract slze of broiler chickens fed wheat- and barley-based diets. Poultly Sci. 72:1731-1739. 3. Brenes, A, W. Guenter, RR Maquardt, and B . k Rother, 1993. Effect of S-glucanose/pentosanose enzyme supplementation on the performance of chickens and laying hens fed wheat, barley, naked oats, and rye diets. Can. J. Anim. Sei. 73941-951.