The Effect of Dietary Alkaline Protease Supplementation on the Performance of Broilers and Layers
Published: June 14, 2013
By: Miriam Tempra (Nuevo Milenio, Inc.), E.S. Luis, F.E. Merca, M.R. Batungbacal and
W.A. Hurtada (University of the Philippines, Los Banos, Laguna)
Summary
Feed enzymes are used to improve the digestibility of feed ingredients and reduce the detrimental effects of antinutritional factors. The use of feed enzymes is a common practice in wheat and barley based poultry diets worldwide. However, enzyme producers have found difficulty in developing efficacious and cost effective products for corn-soybean meal and sorghum-soybean meal based diets. Proteases are used in the food industry but protease preparations are now being utilized for animal feed.
Two feeding trials were conducted to determine the effect of dietary protease supplementation on the performance of broilers and layers. In the broiler study, 320 day-old broiler chicks were randomly assigned to four treatments with eight replications of 10 birds. In the layer study, 120 individually caged 20-week old pullets were randomly distributed to four treatments following a completely randomized design. Each treatment was replicated 30 times with one individually caged pullet per replicate. The dietary treatments for broilers and layers were: Treatment 1, basal diet; Treatment 2, reduced crude protein and amino acid diet without protease supplementation; Treatment 3, treatment 2 diet with 125 ppm protease A; Treatment 4, treatment 2 diet with 200 ppm protease B. The broiler study duration was 42 days while the layer study duration was 12 weeks. Results indicated that a 10% reduction in crude protein and amino acid content of the diet adversely affected the performance of broilers but not of layers. Supplementation with protease A or B did not compensate for the reduction in nutrient content of the broiler diets. Supplementation with protease A or B had no effect on layer performance.
I. INTRODUCTION
Proteolytic enzymes are involved in a great variety of physiological processes and their action can be divided into two different categories. Firstly, limited proteolysis, in which a protease cleaves only one or a limited number of peptide bonds of a target protein leading to the activation or maturation of the formerly inactive protein. Secondly, unlimited proteolysis, in which proteins are degraded into their amino acid constituents.
Since 1958, most of the research efforts in the enzyme field were dedicated to improving the digestibility of some cereals that could replace corn in animal feeds (Fry et al., 1958). Basically the results of this work showed that the addition of the enzyme glucanase improved performance of growing birds when fed barIey-based diets while the inclusion of pentosanases to either wheat or rye-based diets also resulted in better poultry performance (Leslie, 1995). The presence of non-starch polysaccharide (NSP) compounds in feed grains causes an increase in digesta viscosity in the intestine. This increase in viscosity reduces nutrient digestibility and absorption with a resulting negative impact on performance of nonruminant animals (Bedford et al., 1991). As previously mentioned, the main approach to enzyme use in animal feeds has been to improve cereal utilization. However, recently it has been shown that there is great potential in improving the digestibility of other components of the diet, in particular soybean meal. Work by Schang et al. (1997) showed that the proportion of gross energy that is metabolized in corn is larger than in soybean meal (i.e. 89- 91% versus 60-75%). Research has indicated that addition of protease increased the true metabolizable energy (nitrogen corrected) values of several plant protein sources by 4 to 14% (Charlton, 1996).
II. MATERIALS AND METHODS
The enzyme preparations used in the study were provided by two commercial feed additive manufacturers, i.e. from Canada (Protease A) and from Switzerland (Protease B). Protease A is a protease complex of the alkaline serine protease group. Protease B is a preparation of serine protease produced by a genetically modified strain of Bacillus licheniformis.
A total of 320 straight-run Cobb one-day old broiler chicks were purchased and randomly distributed to 32 cages with 10 chicks per cage. Four treatments were assigned to the 32 cages of broilers following a completely randomized design (CRD). Each treatment was replicated eight times with a cage of 10 chicks per replicate. The trial duration was 42 days.
For the layer study, a total of 120 20-week old Hy-line pullets were randomly assigned to four treatments following a CRD. Each treatment was replicated 30 times with one pullet per replicate. The trial duration was 12 weeks.
The following treatments were applied to the broiler and layer diets with nutrient specifications shown in table 1:
Treatment 1 - Basal diets
Treatment 2 - Reduced Crude Protein (CP) and amino acids diets
Treatment 3 - Reduced CP and amino acids diets with 125g/tonne protease A
Treatment 4 - Reduced CP and amino acids diets with 200g/tonne protease B
Treatment 2 - Reduced Crude Protein (CP) and amino acids diets
Treatment 3 - Reduced CP and amino acids diets with 125g/tonne protease A
Treatment 4 - Reduced CP and amino acids diets with 200g/tonne protease B
Table 1 - Nutrient specifications of broiler and layer diets.
III. RESULTS AND DISCUSSIONS
Table 2 shows the results for broilers. The 10% reduction in CP and amino acid content of the diets resulted in a significant depression in body weight gain and feed conversion efficiency of broilers. However, feed consumption was not influenced with the reduction of CP and amino acids of the diets.
Supplementation with protease A or B did not improve the body weight gain and feed conversion efficiency of broilers fed diets with reduced CP and amino acid content. Likewise, feed consumption was not affected by the addition of protease A or B to the protein and amino acid reduced diets.
Table 2 - Average performance of broilers fed basal or reduced CP and amino acids diets supplemented with two preparations of alkaline proteases from 1-42 days of age.
The 10% reduction in dietary CP and amino acid content may have been too high for the broilers such that supplementation with either protease A or B could not compensate for the deficiency in nutrients. Feed conversion efficiency responses differ with the level of reduction in CP and amino acids and level of protease activity. Supplementation of exogenous enzymes can positively influence endogenous nutrient losses and the efficiency of the production of endogenous enzymes (Cowieson et al., 2005; Jiang et al., 2008 and Liu et al., 2008). The reduction in protein and amino acids in the diets by 10% could have induced a deficiency in available amino acids for the synthesis of endogenous enzymes. Variability in feed conversion efficiency response suggests the importance of evaluating the availability and levels of substrates for enzyme in feeds and matching them with specific types of enzyme activities to achieve the optimal response (Hruby, 2009).
Table 3 shows the results for layers which indicate that the 10% reduction in CP and amino acid content of the diet did not adversely affect egg production rate, egg weight, feed consumption and feed conversion efficiency. Supplementing the reduced CP and amino acid diet with the proteases did not influence egg production rate, feed consumption or feed efficiency. Eggs laid by hens fed the CP and amino acid reduced diet supplemented with protease B had significantly lower weight than the control treatment.
Table 3 - Average performance of layers fed basal or reduced CP and amino acids diets supplemented with two preparations of alkaline proteases from 20-32 weeks of age.
Aklilu (2003), Seguerra (2003) and Bunan (2008) reported significant depression in egg production rate of layers fed diets with reduced CP and amino acid content. The different result seen in this study could be due to different layer strains and different CP and amino acid levels in the diets.
Jackson et al. (1999), Elliot (2002) and Ru (2009) reported positive effects of protease supplementation on egg production from layers. The variability of results obtained from different studies on protease supplementation may be due to differences in activity and concentration of protease preparations including the use of enzyme blends compared with purified protease as well as the microbial source of the enzymes.
IV. CONCLUSION
Reduction in protein and amino acid content of the diets significantly depressed the body weight gain of broilers. Supplementation with proteases did not affect body weight gain, feed consumption or feed conversion efficiency.
Egg production, egg weight, feed consumption, feed conversion efficiency of layers were not affected by the reduction in CP and amino acid content of the diet or by supplementation with proteases.
Under the conditions of this study, it can be concluded that a reduction of 10% crude protein and amino acid content of the diets adversely affected the performance of broilers but not of the layers. Supplementation of the reduced CP and amino acid diets with protease A or B did not compensate for the reduction in nutrient content of the broiler diets. Layer performance was not significantly affected by protease supplementation of the diet.
REFERENCES
Aklilu M (2003) Graduate Thesis, University of the Philippines Los Baños, Laguna.
Bedford MR, Classen HL, Campbell GL (1991) Poultry Science 70, 1571-1577.
Bunan AA (2008) Graduate Thesis, University of the Philippines Los Baños, Laguna.
Charlton P (1996) Expanding enzyme applications: Higher amino acid and energy values for vegetable proteins. Biotechnology in the Feed Industry. Proceedings of Alltech's 12th Annual Symposium. Nottingham University Press, Loughborough, Leics, UK. (TP Lyons, KA Jacques Eds).
Cowieson AJ, Adeola O (2005) Poultry Science 84,1860-1867.
Elliot M (2002) Enzyme Use in Commercial Layer Production. Proceedings of the Multi- State Poultry Meeting, Indianapolis, Indiana, USA.
Fry RE, Allred JB, Jensen LS, McGinnis J (1958) Poultry Science 37, 281-288.
Hruby M, Pierson EE (2009) Implications of enzyme use in corn-sorghum-soy diets on performance, nutrient utilization and gut microflora. Proceedings of the Multi-State Poultry Feeding & Nutrition Conference, Indianapolis, Indiana, USA.
Jackson ME, Fodge DW, Hsiao HY (1999) Poultry Science 78, 1737-1741.
Jiang Z, Zhou Y, Fuzeng L, Han Z, Want T (2008) Asian Australasian Journal of Animal Science 21(1), 97-102.
Leslie AJ (1995). Future potential for cereal enzymes. Proceedings of the International launch of Allzyme Vegpro, Alltech Inc., USA.
Liu N, Ru J, Li FD, Cowieson AJ (2008) Journal of Animal Science 86, 3432-3439.
Ru Y (2009) The Key to More Profitable Egg Production. Press Release. Danisco A/S, Communications, Langebrogade 1, Copenhagen, Denmark.
Schang MJ, Azcona JE, Arias JE (1997) Biotechnology in the Feed industry. Alltech Biotechnology Center Symposium (T.P. Lyons, Ed) p, 95.
Seguerra MJ (2003) Undergraduate Thesis, University of the Philippines Los Baños, Laguna.
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IFF - International Flavors & Fragrances
27 de agosto de 2013
Hello there from Spain. Interesting findings and showing some of the claims seen in the industry (10% CP reduction) might be far too agressive. I do believe proteases do have a role in some way improving digestibility of the protein/AA in feed. But is this improvement coming from direct effect of the protease in the feed protein or should be also take into account a positive effect of the enzyme in reducing the endogenous losses?. This is a question I would like Miriam to answer please. And yet: would it be the case that protease effect needs to be accompanied by the additional presence of another NSPase enzyme?. I also like to underline the fact that there is no mention of how digestible protein in the feeds is; is there much SBM, or more of RSM, sunflower or other...?. Since protein and AA are expressed in total content, this can alos have an effect in results. Many thanks from Spain.
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