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J APPL POULT RES 2007. 16:481-493. doi:10.3382/japr.2006-00082
© 2007 Poultry Science Association
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Research Reports

Response to Varying Dietary Energy and Protein With or Without Enzyme Supplementation on Growth and Performance of Leghorns: Growing Period

C. L. Novak*,1,2, H. M. Yakout{dagger} and J. Remus{ddagger}

* Department of Animal and Poultry Science, Virginia Tech, Blacksburg, VA 24061; {dagger} Poultry Production Department, Alexandria University, El-Shatby 21545, Alexandria, Egypt; and {ddagger} Danisco Animal Nutrition, 411 East Gano, St. Louis, MO 63147

Correspondence: 1 Corresponding author: CLNovak{at}landolakes.com


   SUMMARY
TOP
 SUMMARY
DESCRIPTION OF PROBLEM
 MATERIALS AND METHODS
 RESULTS AND DISCUSSION
 CONCLUSIONS AND APPLICATIONS
 REFERENCES AND NOTES
 
Bovans White Leghorn pullets were utilized to evaluate the use of an enzyme cocktail from 0 to 126 d of age. Dietary treatments varied in CP, ME, and enzyme (EZ) supplementation. Feed intake, BW gain, and feed conversion ratio data were gathered in addition to determining nutrient retention and digestibility during the trial. Cumulatively, feed consumption was decreased by EZ supplementation when added to a required ME diet. Body weight gains were similar across dietary treatments; however, cumulative feed conversion ratio was significantly improved with EZ supplementation. Interactions regarding nutrient retention and digestibility were numerous. Similar responses were noted for energy and protein retention values during the trial with changes in response to dietary treatments as the pullets aged. Compared with feeding an industry applicable diet (required ME/CP without EZ – $0.27/lb gain), all dietary treatments reduced production costs with significant reductions when reducing CP. Lowest feed cost ($)/lb gain and percent excreta N was feeding pullets a diet with reduced ME and CP supplemented with EZ ($0.262/lb gain; 5.19% N). Possible further reductions in ME or dietary CP, or both, with EZ supplementation may prove to be even more economical and environmentally friendly.

Key Words: dietary energy • protein • enzyme supplementation • pullet


   DESCRIPTION OF PROBLEM
TOP
 SUMMARY
 DESCRIPTION OF PROBLEM
MATERIALS AND METHODS
 RESULTS AND DISCUSSION
 CONCLUSIONS AND APPLICATIONS
 REFERENCES AND NOTES
 
High egg production and laying efficiency are characteristic of the modern laying hen. Improvements in efficiency must focus on maximizing nutrient utilization from current and future feedstuffs [1]. The use of commercial enzymes (EZ) in diets can improve nutrient digestibility and absorption by maintaining gut integrity, which in turn reduces pollution associated with poultry manure and allows for the use of lower cost ingredients [2, 3, 4, 5].

In the United States, corn and soybean meal are the major ingredients supplying energy and protein to commercial layers [6]. Although corn is less affected by enzyme supplementation than other grains because of low concentrations of nonstarch polysaccharides (NSP), a 2 to 3% improvement in feed conversion has been reported for EZ supplemented corn-based diets [7]. Soybean meal, however, contains nondigestible carbohydrates, which could be available to hens with proper EZ supplementation [7].

The use of exogenous enzymes to degrade NSP has been evaluated for diets high in barley, oats, or wheat [8, 9]. Feeding diets high in NSP has been shown to inhibit starch digestion by increasing digesta viscosity [10]. The addition of exogenous xylanase to wheat-based diets can decrease digesta viscosity and improve broiler growth [11]. Noy and Sklan [12] reported cornstarch ileal digestibility rarely exceeds 85% in broilers between 4 and 21 d of age, indicating opportunities to further improve the digestibility of resistant starch in the jejunum and ileum through amylase supplementation. Furthermore, proteases could potentially degrade such soybean proteins as glycinin and ß-conglycinin and some antinutritional factors (lectin and trypsin-inhibitor) in inadequately processed soybean meal [13].

The current study investigated growth traits and nutrient utilization of White Leghorn pullets fed a corn, soybean meal (SBM), wheat middlings-based diet supplemented with an enzyme cocktail containing amylase, protease, and xylanase to 126 d of age, prior to the onset of egg production.


   MATERIALS AND METHODS
TOP
 SUMMARY
 DESCRIPTION OF PROBLEM
 MATERIALS AND METHODS
RESULTS AND DISCUSSION
 CONCLUSIONS AND APPLICATIONS
 REFERENCES AND NOTES
 
Animals and Diets
Bovans White Leghorn chicks (n = 768) [14] were received on the day of hatch from a local hatchery, wing-banded, and randomly assigned to 1 of 8 dietary treatment groups (8 reps per treatment). Body weights (37.2 g/chick) were obtained prior to placing the chicks in a pen. Chicks were housed 12 per pen (density 48 in.2/pullet) in 2 separate rooms (32 pens/room), which were environmentally controlled with a daily target temperature of 31°C at placement with subsequent temperature reductions based on bird comfort until a final temperature of 22°C was reached. Commercial management practices were used during the trial.

A 2 x 2 x 2 factorial arrangement implementing 2 levels of dietary energy (E– required [14] vs. 3% reduction), dietary crude protein (CP –required [14] vs. 1% point reduction), and with or without Avizyme 1502 (EZ) supplementation [15] (Table 1Go). Avizyme 1502 was added to basal diets at a rate of 0.05% from 0 to 56 d and reduced to 0.0375% 56 to 126 d of age. Avizyme 1502 contained (per g) a guaranteed minimum of 800 units/g of {alpha}-amylase from Bacillus amyloliqufaciens, 8,000 units/g of proteases from Bacillus subtilis, and 600 units/g of ß-xylanase from Trichoderma longibrachiatum [16]. The accuracy of enzyme inclusion was determined by amylase content of the finished diets (Table 2Go).


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  		Table 1. Composition and nutrient content of pullet starter, developer, grower, and prelay diets1,2
 

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  		Table 2. Actual enzyme content determined by amylase activity in experimental diets
 
Corn, soybean meal, and wheat middling basal diets (Table 1Go) were formulated to meet Bovans White Management Guide recommendations [14] for the starter from 0 to 42 d (calculated: 2,980 ME kcal/kg: CP, 20%; analyzed: 4,130 GE cal/g: CP, 21.43%), grower from 43 to 70 d (calculated: 2,970 ME kcal/kg: CP, 18%; analyzed: 3,997 GE cal/g: CP, 18.21%), developer from 71 to 105 d (calculated: 2,960 ME kcal/kg: CP, 16%; analyzed: 3,967 GE cal/g: CP, 16.23%), and prelay from 106 to 126 d (calculated: 2,930 ME kcal/kg: CP, 15%; analyzed: 3,832 GE cal/g: CP, 15.33%). Reduced ME, CP, or ME and CP basal diets were formulated and mixed using the aforementioned diets for each growing period. Each basal diet (n = 4) was then divided into 2; one with EZ and one without, totaling 8 dietary treatments per period.

Feed samples collected at mixer using a probe during each phase of feeding were subsequently ground using a 1-mm screened Tecator cyclotec grinder [17] to prep for analysis. Feed and water (cup drinkers) were provided ad libitum. All diets were analyzed for gross energy and protein, according to AOAC [18]. Nitrogen concentration was determined by the combustion method using a Nitrogen Analyzer [19]. The following equation was used to convert to CP: N x 6.25. Gross energy was determined by bomb calorimetry using a Parr 1261 adiabatic calorimeter [20].

Measurements
Dietary treatments were evaluated from 0 to 126 d of age by determining weekly feed intake (FI) or disappearance, BW gain (BWG: calculated per period and obtained every 2 wk from BW by pen), and calculated FCR. Excreta collected from each pen at 42, 70, 105, and 126 d of age were analyzed to measure protein and energy retention. Chromic oxide was added to all diets at 3 gm/kg as an inert marker. Chromic oxide was analyzed according to Czarnocki et al. [21]. At 126 d, 3 pullets per pen were euthanized by cervical dislocation, and ileal contents (from Meckel’s diverticulum to the ileo-cecal junction) were collected. Ileal samples of the pullets from each pen were pooled for analysis of chromium, N, and energy as described earlier. All excreta samples were frozen and stored at –20°C until further processed. Frozen excreta and ileal samples were thawed, transferred to aluminum pans, and placed in a 65°C oven for 3 d. After drying, all samples were ground (Tecator cyclotec) through a 0.5-mm screen to prep for analysis. Diet, excreta, and ileal dry matter were determined by oven drying at 105°C for 24 h. Values obtained were used to calculate nutrient retention and ileal digestibility using the following equation:


Formula

After calculating the percent energy and protein retention, kilocalories of energy or grams of protein/bird/day for each period and overall were calculated using analyzed values for gross energy and CP in diets used in the trial. All animal procedures were approved by the Virginia Tech Animal Care and Use Committee. Economics were calculated as $/lb gain and $/kg gain [22].

Statistical Analysis
The experimental design for the current experiment was a randomized complete block design. Blocking was implemented to reduce the effect of room. The ANOVA was performed by PROC MIXED procedures of SAS [23] with the following model:


Formula

where Yijk = variable measured; µ = overall mean; Ri = effect as a result of the ith block; aj = effect of the jth level of a; bk = effect of the kth level of b; (ab)jk interaction effect of the jth level of a and the kth level of b; and eijkl = error component.

Blocks (room), E, CP, and EZ were considered fixed effects. Utilizing SAS, average values for each period were generated and subsequently analyzed separately to determine differences between treatment means established by the LSMEANS statement.


   RESULTS AND DISCUSSION
TOP
 SUMMARY
 DESCRIPTION OF PROBLEM
 MATERIALS AND METHODS
 RESULTS AND DISCUSSION
CONCLUSIONS AND APPLICATIONS
 REFERENCES AND NOTES
 
Investigated in the current study was a cocktail of enzymes, including amylase, protease and xylanase, combined with reduced ME and CP to determine efficacy when raising Leghorn pullets. Mortality was minimal (<0.02%) and similar across treatment groups. Analysis of diets for EZ content was similar to calculated inclusions. Analyzed dietary CP and gross energy levels in the basal diets were somewhat different from formulated values. Because of turnover of ingredients at the mill, variation in nutrients present in raw ingredients may have changed the final nutrient levels. Discussion related to performance and nutrient intake and excretion are based on analyzed values. Ingredient ME values used for formulation were based on NRC, 1994 [24]. Due to the lack of research available evaluating the use of EZ supplementation in pullet diets, it was necessary to extrapolate from broiler data where applicable.

BW Gain and CV
Neither CP nor ME dietary reductions nor EZ supplementation alone had any effects on BWG or uniformity through 126 d (Table 3Go). Average BWG and CV at 126 d of age were 1,258 g and 7.63, respectively. There was a CP x EZ interaction (P ≤ 0.05) noted at 126 d of age when evaluating CV. Decreasing CP with no EZ improved (P ≤ 0.01) CV, whereas supplementing EZ to a required CP diet improved (P ≤ 0.07) CV. Although Douglas et al. [5] observed a similar response with enzyme supplementation to broilers from 0 to 14 d of age, the trial was a very short trial and may not be applicable to ours.


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  		Table 3. Body weight gain and uniformity from 0 to 126 d of age for Leghorn pullets fed an enzyme supplement
 
Feed Intake and FCR
Feed intake and FCR of Bovans White Leghorn pullets from 0 to 126 d are presented in Table 4Go. Feed intake was reduced when pullets were fed diets supplemented with EZ during the developer period (2,205 vs. 2,142 g/pullet). During the grower period, EZ supplementation slightly reduced cumulative FI when combined with a 3% drop in dietary ME but reduced FI when combined with required ME (P ≤ 0.066). An interaction including ME x EZ (P ≤ 0.04) was observed when evaluating 0 to 126 d of FI. The FI of pullets was decreased (P ≤ 0.002) when feeding a diet containing required ME with EZ supplementation, whereas little response was noted when the reduced ME diets were supplemented. This relationship suggests that the required ME diet was supplying nutrients above that needed for optimal growth and explains the lack of response of reducing ME, CP, or both, on FI and BWG during the entire growing period. A further reduction in these components of the diet may have been needed.


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  		Table 4. Feed consumption and feed conversion ratio from 0 to 126 d of age for Leghorn pullets fed an enzyme supplement
 
No significant effects were noted as a result of dietary treatments on FCR during the starter, developer or prelay periods. However, cumulative FCR improved (P ≤ 0.02) by 8 points with EZ supplementation (4.64 vs. 4.72 g of feed/g of gain). Also, a significant interaction (CP x ME x EZ) was noted during the grower period. This came about through improved FCR for pullets fed a diet with reduced ME and EZ supplementation combined with reduced CP. When feeding a required CP diet without EZ supplementation, reducing ME improved FCR (P ≤ 0.05). In addition, EZ supplementation improved FCR when feeding a required CP/ME diet. This was the only interaction involving CP, ME, and EZ and may be attributed to chance. Feed conversion ratio was generally improved when supplementing broiler diets with exogenous enzymes [3, 25, 26], but the reason behind the improvement was a decrease in FI or an increase in BWG. In the present trial, BWG was similar, but the decrease in FI improved FCR significantly. This may indicate the nutrient levels in the present trial were above that needed for optimum growth.

Energy Retention (Percent and Absolute) and Digestibility
Main effects of dietary treatments affecting energy retention and digestibility are presented in Table 5Go; however, because of significant 2-and 3-way interactions, these results have not been discussed. In addition to main affects noted in Table 5Go, there was a 3-way interaction (CP x ME x EZ) during the grower (P ≤ 0.02 and 0.07) and prelay (P ≤ 0.0001 and 0.01) periods for percent and absolute energy retention, respectively. This resulted from an increase in percent energy retention with EZ supplementation when required CP was combined with reduced ME; however, supplemented to a reduced CP diet, energy retention increased with required ME and decreased with reduced ME during the grower period. Similar results were also observed regarding absolute energy retention (kcal/pullet/d; Table 6Go) during the grower period, with the exception when feeding required CP, total energy retained decreased feeding the EZ nonsupplemented diet. A similar response was noted overall. During the prelay period, percent energy retained was decreased in a similar manner with EZ supplementation when reduced CP was combined with reduced and required ME (no interaction), but when EZ was supplemented to a required CP diet, energy retention decreased only with required ME.


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  		Table 5. Percent energy and protein retention from 0 to 126 d of age for Leghorn pullets fed an enzyme supplement
 

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  		Table 6. The energy and protein retention per bird per day from 0 to 126 d of age for Leghorn pullets fed an enzyme supplement
 
Interaction of ME x CP (P ≤ 0.006) occurred during the grower, developer, and prelay periods. Percent energy retention was not affected by dietary CP during the grower period when combined with reduced ME, but was significantly reduced when feeding required CP/ME. Furthermore, absolute energy retention (kcal/pullet/d) was similar to percent retained with one exception. When pullets were fed a diet with reduced CP/ME, absolute retention was decreased compared with feeding diets containing reduced CP and required ME or required CP and reduced ME. However, during the developer period, percent energy retention in pullets was increased when reducing dietary CP/ME.

Additionally, ME x EZ interactions (P ≤ 0.03) occurred during the starter and developer periods. Percent energy retention increased (P ≤ 0.001) when pullets were fed a required ME diet with EZ supplementation during the starter period. Because of the lack of response (P ≤ 0.4) when supplementing the reduced ME diet with EZ, percent energy retention was lower (P ≤ 0.001) than that for pullets consuming the required ME/EZ-supplemented diet. Also, during the starter period, it was noted that there was a decrease (P ≤ 0.0005) in FI when feeding the required ME diet with EZ supplementation indicating that the additional energy released by supplementing EZ was used to meet the energy requirements and reduced FI accordingly, whereas supplementing the reduced ME diet with EZ did not influence FI. When examining absolute kilocalories retained during the starter period, retained values ranged from 72.8 to 75.1 kcal/pullet/d with no differences noted among treatments. This result indicates that the pullets ate to meet their energy requirement. Although there was no interaction during the grower period involving percent energy retention, there was a ME x EZ interaction (P ≤ 0.04) when evaluating the absolute kilocalories retained which continued through the prelay period. During this time, the highest (P ≤ 0.02) absolute energy retention (kcal/pullet/d) was obtained from pullets fed the required ME without EZ supplementation. All other comparisons were similar. When feeding pullets a reduced ME diet, supplementing EZ during the developer period increased (P ≤ 0.053) percent energy retention. Little change was noted when adding EZ to a diet adequate in ME, but with or without EZ supplementation, percent energy retention was greater when feeding the required ME diet.

Lastly, there was a CP x EZ interaction (P ≤ 0.03) observed through the developer period. Pullets fed reduce CP diets with or without EZ had similar retention values, whereas allowing access to a required CP diet without EZ reduced energy retention during the starter and grower periods. The significant improvement in FCR for pullets receiving reduced CP diets and EZ supports energy retention data during the grower period. As more energy was available, possibly through EZ action, a slight improvement in BWG coupled with a significant reduction in FI improved FCR. During the developer period, pullets fed reduced CP diets with EZ retained more energy, whereas retention was reduced when birds were supplied diets with required CP and EZ.

Although ileal energy digestibility was higher (P ≤ 0.04) for hens fed reduced ME than those fed required ME diets (74.93 vs. 73.07), there was an interaction of CP x ME x EZ. Energy digestibility was decreased in pullets with EZ supplementation to a diet combining reduced CP and reduced ME or required CP and required ME. This response was similar to that observed for energy retention during the prelay period with the exception of no response of EZ when supplemented to a diet reduced in CP containing required ME. Retention during the prelay period (determined at 126 d) was similar to digestibility with one exception. When feeding the reduced CP diet, there was no interaction noted in regard to retention, and no difference in digestibility was noted with EZ supplementation to a reduced CP/required ME diet.

The addition of exogenous enzymes (xylanase or ß-glucanase) can enhance nutrient digestion and utilization in wheat and barley based diets when fed to chickens [27, 28]. It is thought that soluble NSP increases water-holding capacity, which could interact with water molecules to form a network, thus increasing the viscosity of digesta. A corn/soybean meal based diet is very low in soluble NSP, but an intestinal viscosity as low as 1 Pa second (mPa·s) can negatively impact nutrient diffusion and absorption [29] and alter retention of nutrients and subsequent performance. In our study, wheat middlings included as high as 17% was used to achieve a 3% ME reduction, which has been shown to increase intestinal viscosity and damage intestinal morphology [1], which led to poor nutrient absorption and lower nutrient retention. Additionally, corn/soybean meal directed enzymes may improve energy and protein digestion by releasing these components trapped within the cell wall. Proteases and xylanases may improve the breakdown of this barrier and enhance nutrient availability. Moreover, as the benefit of enzymes to help NSP digestion is reduced in older birds, pullets reaching the developer and prelay periods may be expected to benefit less from enzyme supplementation. It was also determined that the addition of exogenous enzymes (Avizyme 1500—50% enzyme concentration as 1502) could hydrolyze the high molecular weight subfraction of arabinoxylan and decrease the formation of viscous solution in digestive tract.

Protein Retention (Percent and Absolute) and Digestibility
In the present trial, EZ supplementation increased protein retention was observed during the starter and grower but not during the developer period, with a decrease during the prelay period. Significant interactions involving ME, CP, and EZ were observed, which may make main effects misleading. Rafuse et al. [30] reported that enzyme supplementation improved protein digestibility of corn-based diets when fed to laying hens. It was also noted that age may play a role in the ability of chickens to digest NSP present in corn. As individual birds age, the benefit of enzymes may be diminished due to their ability to utilize NSP more efficiently. This may explain the enzyme effect on protein and energy retention as our pullets aged. It may be assumed that the lack of response of enzymes on nutrient retention may also be related to nutrients needed for the pullet to grow optimally. If the present diets were sufficient in nutrients without enzyme benefit, retention would not increase.

A number of interactions were noted with nonconsistent responses across periods. Protein retention (CP x ME x EZ) during the prelay period decreased with enzyme supplementation to a diet consisting of reduced CP and reduced ME, whereas the opposite was observed when required CP was used for the same comparison. There was also a significant increase in percent protein retention when feeding a required ME diet without EZ supplementation. In addition, a significant CP x ME x EZ interaction was observed during grower, prelay, and overall for absolute protein retention. There were no differences noted when feeding reduced CP in combination with varying ME or EZ with one exception. Supplementing a reduced CP/ME diet with EZ during the prelay period reduced absolute protein retention compared with no EZ. When feeding a diet containing required CP and EZ, reducing ME improved protein retention (g/pullet/d) during the grower and prelay, but not overall. In addition, when feeding pullets the required CP/reduced ME diet with EZ, absolute protein retention was improved compared with no EZ supplementation during the grower period. Lastly, reducing ME in a required CP diet without EZ decreased absolute protein retained during the prelay and overall.

During the grower period (ME x CP), reducing ME resulted in increased percent protein retention when combined with required CP while little response was noted when combined with reduced CP. During the developer period, feeding a reduced CP diet with reduced or required ME and required CP/ME resulted in similar percent and absolute protein retention, and all were significantly higher than that of feeding the required CP/reduced ME diet. When comparing the above interaction in regards to FI, pullets fed the required CP/reduced ME diet ate significantly more feed than those fed the required CP/ME diet, indicating that they were eating to meet their energy requirement. The retention of protein did not follow this trend.

During the starter period, there was a ME x EZ interaction that showed that the highest percent protein retention was observed when pullets were fed a required ME, EZ-supplemented diet, with no response noted when supplementing a reduced ME diet.

During the starter and grower periods (CP x EZ), percent protein retention was improved (P ≤ 0.0002 and 0.02) when reducing CP without EZ. Crude protein had no effect on retention with EZ supplementation. When evaluating absolute protein retained, similar grams of protein were retained when feeding the nonEZ-supplemented feed with required or reduced CP and reduced CP with EZ, but were significantly lower compared with feeding the required CP with EZ supplementation. During the developer period, there was an improvement (P < 0.001) in percent and absolute protein retention when supplementing EZ to CP reduced diets.

Protein digestibility (CP x ME x EZ) was decreased with enzyme supplementation to a diet consisting of reduced CP/ME or required CP/ME compared with no EZ supplementation, whereas digestibility was improved (P < 0.04) with EZ supplementation to a required CP and reduced ME diet. When feeding the required CP diets, EZ supplementing a reduced ME diet increased protein digestibility, whereas a similar response (P = 0.52) was observed when feeding the reduced CP diet without EZ. This response was similar to what was observed for protein retention during the prelay period.

Percent Excreta Nitrogen and Economics
Overall, ME (P ≤ 0.052), CP (P ≤ 0.0001), and EZ supplementation (P ≤ 0.03) reduced percent excreta nitrogen (Table 7Go). The effect of ME on excreta N was most prevalent during the developer period (P ≤ 0.05), whereas the effect of reduced CP was observed throughout the trial with an 8% reduction in percent excreta N. This reduction was consistent with that reported in broilers and broiler breeders [31, 32]. Overall, EZ supplementation reduced percent excreta nitrogen by 2% with the main response noted during the starter period.


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  		Table 7. Excreta N and economic evaluation of Leghorn pullets fed an enzyme supplement from 0 to 126 d of age
 
Overall, reducing CP reduced feed cost by around $0.005/lb of gain ($0.01/kg of gain) as shown in Table 7Go. Neither ME nor EZ supplementation had a significant affect on cost of raising pullets to 126 d during the present trial.


   CONCLUSIONS AND APPLICATIONS
TOP
 SUMMARY
 DESCRIPTION OF PROBLEM
 MATERIALS AND METHODS
 RESULTS AND DISCUSSION
 CONCLUSIONS AND APPLICATIONS
REFERENCES AND NOTES
 

  1. Supplementing a commercial corn, soybean meal, and wheat middling diet with EZ did not affect growth of White Leghorn pullets but resulted in a significant improvement in cumulative FCR due to reduced feed intake.
  2. Age of pullets plays a role in nutrient utilization.
  3. Percent excreta nitrogen at 126 d will be decreased when reducing dietary energy, protein, or EZ supplementation but with further reductions when all are implemented.
  4. Reducing CP reduces cost of production and maintains performance.
  5. A greater energy or protein reduction may be possible to further enhance enzyme response.


   FOOTNOTES
 
2 Commercial Poultry Nutrition, Land O’Lakes Purina Feed, LLC, 12200 N. Ambassador Dr., Suite 225, Kansas City, MO 64163. Back


   REFERENCES AND NOTES
TOP
 SUMMARY
 DESCRIPTION OF PROBLEM
 MATERIALS AND METHODS
 RESULTS AND DISCUSSION
 CONCLUSIONS AND APPLICATIONS
 REFERENCES AND NOTES
 

  1. Jaroni, D., S. E. Scheideler, M. Beck, and C. Wyatt. 1999. The effect of dietary wheat middlings and enzyme supplementation. 1. Late egg production efficiency, egg yields, and egg composition in two strains of leghorn hens. Poult. Sci. 78:841–847.[Abstract/Free Full Text]
  2. Francis, P. A., K. R. Robbins, A. G. Mathew, F. A. Draughon, and D. A. Golden. 1999. The effects of Avizyme® in rye or corn based diets on broiler performance, microbiological and fermentation changes in the gastrointestinal tract. Poult. Sci. 78(Suppl. 1): S30. (Abstr.)
  3. Zanella, I., N. K. Sakomura, F. G. Silversides, A. Fiquerirdo, and M. Pack. 1999. Effect of enzyme supplementation of broiler diets based on corn and soybeans. Poult. Sci. 78:561–568.[Abstract/Free Full Text]
  4. Cook, M. E., B. M. Drake, and E. E. M. Pierson. 2000. A blend of xylanase, amylase and protease (Avizyme® 1500) improves laying hen egg production, feed efficiency, and livability when supplemented in corn-soy based diets. Poult. Sci. 79(Suppl. 1):21. (Abstr.)
  5. Douglas, M. W., C. M. Parsons, and M. R. Bedford. 2000. Effects of various soybean meal sources and Avizyme® on chick growth performance and ileal digestible energy. J. Appl. Poult. Res. 9:74–80.[Abstract/Free Full Text]
  6. Sohail, S. S., M. M. Bryant, D. A. Roland, Sr., J. H. A. Apajalahti, and E. E. Pierson. 2003. Influence of Avizyme® 1500 on performance of commercial leghorns. J. Appl. Poult. Res. 12:284–290.[Abstract/Free Full Text]
  7. Cowan, W. D. 1993. Understanding the manufacturing, distribution, application, and overall quality of enzymes in poultry feeds. J. Appl. Poult. Res. 2:93–99.[Free Full Text]
  8. Annison, G. 1992. Commercial Enzyme supplementation of wheat based diets raises ileal glycanase activities and improves apparent metabolizable energy, starch and pentosan digestibilities in broiler chickens. Anim. Feed Sci. Technol. 38:105–121.[CrossRef]
  9. Bedford, M. R., and H. L. Classen. 1992. Reductions of intestinal viscosity through manipulation of dietary rye and pentosanase concentration is affected through changes in carbohydrate composition of the intestinal aqueous phase and results in improved growth rate and feed conversion efficiency of broiler chicks. J. Nutr. 122:560–569.[Abstract/Free Full Text]
  10. Campbell, G. L., and M. R. Bedford. 1992. Enzyme applications for monogastric feeds: A review. Can. J. Anim. Sci. 72:449–466.
  11. Brenes, A., M. Smith, W. Guenter, and R. R. Marquardt. 1993. Effect of enzyme supplementation on the performance and digestive tract size of broiler chicks fed wheat- and barley-based diets. Poult. Sci. 72:1731–1739.[Web of Science][Medline]
  12. Noy, Y., and D. Sklan. 1994. Digestion and absorption in the young chick. Poult. Sci. 73:366–373.
  13. Thrope, J., and J. D. Beal. 2001. Vegetable proteins meals and the effects of enzymes. Pages 125–143 in Enzymes in Farm Animal Nutrition. M. R. Bedford and G. G. Partridge, ed. CABI Publ., Wallingford, Oxon, UK.
  14. Bovans White Leghorn Breeder Guide. Centurion Poult. Inc., Lexington, GA.
  15. Danisco Animal Nutrition, St. Louis, MO.
  16. Each enzyme has its own activity and definition (and source organism) as follows: xylanase: 1 U is the amount of enzyme which liberates 0.5 µmol of reducing sugar (expressed as xylose equivalents) from a cross-linked oat spelt xylan substrate at pH 5.3 and 50°C in 1 min. Protease: 1 U is the amount of enzyme which liberates 1 micromole of phenolic compound (tyrosine equivalents) from a casein substrate per minute at pH 7.5 and 40°C. Amylase: 1 U is the amount of enzyme that liberates 1 micromole of glucosidic linkages from a water insoluble cross-linked starch polymer substrate per minute at pH 6.5 and 37°C.
  17. 1093 Sample Mill, Box 70. 3-263 21 Hoganas, Sweden.
  18. AOAC. 1995. Official Methods of Analysis. 16th ed. Assoc. Off. Anal. Chem., Washington, DC.
  19. Perkin Elmer Nitrogen Analyzer, 2410 Series II. Perkin Elmer Instruments, Wellesley, MA.
  20. Parr Instrument Co., Moline, IL.
  21. Czarnocki, J., I. R. Sibbald, and E. V. Evans. 1961. The determination of chromic oxide in samples of feed and excreta by acid digestion and spectrophotometry. Can. J. Anim. Sci. 41:167–179.
  22. Cumulated feed cost ($)/lb gain = feed cost ($/pullet/18 wk)/cumulative gain (lb/18 wk), Cumulated feed cost ($/pullet/18 wk) = ingredient cost (finished feed – $/lb) x FI (lb) for starter + grower + developer + prelay). Ingredient cost (finished feed – $/lb) = (total ingredient cost (feedstuffs)/ton finished feed)/2,000. Cumulated feed cost ($)/kg gain = cumulated feed cost ($)/lb gain x 2.205.
  23. SAS. 2000. Statistical Analysis System Proprietary Software. Release 8.1. SAS Inst. Inc., Cary, NC.
  24. National Research Council. 1994. Nutrient Requirement of Poultry, 9th ed. Natl. Acad. Press, Washington, DC.
  25. Café, M. B., C. A. Borges, C. A. Fritts, and P. W. Waldroup. 2002. Avizyme improves performance of broilers fed corn-soybean meal-based diets. J. Appl. Poult. Res. 11:29–33.[Medline]
  26. Wang, Z. R., S. Y. Qiao, W. Q. Lu, and D. F. Li. 2005. Effects of enzyme supplementation on performance, nutrient digestibility, gastrointestinal morphology, and volatile fatty acid profiles in the hindgut of broilers fed wheat-based diets. Poult. Sci. 84:875–881.[Abstract/Free Full Text]
  27. Pettersson, D., and P. Aman. 1989. Enzyme supplementation of a poultry diet containing rye and wheat. Br. J. Nutr. 62:139–149.[CrossRef][Web of Science][Medline]
  28. Bedford, M. R. 1995. Mechanism of action and potential environment benefits from the use of feed enzymes. Anim. Feed Sci. Technol. 53:145–155.[CrossRef]
  29. Bedford, M. R., and A. J. Morgan. 1996. The use of enzymes in poultry diets. World’s Poult. Sci. J. 52:61–68.[CrossRef][Web of Science]
  30. Rafuse, J. L., F. G. Silversides, M. R. Bedford, and P. H. Simmins. 2004. Effect of wheat cultivar and enzyme supplementation on nutrient availability and performance of laying hens. Can. J. Anim. Sci. 84:397–402.
  31. Pope, T., L. N. Loupe, P. B. Pillai, and J. L. Emmert. 2004. Growth performance and nitrogen excretion of broilers using a phase-feeding approach from twenty-one to sixty-three days of age. Poult. Sci. 83:676–682.[Abstract/Free Full Text]
  32. Lopez, G., and S. Leeson. 1995. Nitrogen content of manure from older broiler breeders fed varying quantities of crude protein. J. Appl. Poult. Res. 4:390–394.[Abstract/Free Full Text]



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C. L. Novak, H. M. Yakout, and J. Remus
Response to Varying Dietary Energy and Protein With or Without Enzyme Supplementation on Leghorn Performance and Economics. 2. Laying Period
J. Appl. Poult. Res., January 1, 2008; 17(1): 17 - 33.
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