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METABOLISM AND NUTRITION |
Institut für Ernährungswissenschaften, Universität Halle-Wittenberg, 06099 Germany
2 Corresponding author: markus.rodehutscord{at}landw.uni-halle.de
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ABSTRACT |
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 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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Key Words: amino acid • digestibility • regression • comparison • bird
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INTRODUCTION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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Feed formulation on a digestible AA basis requires information on whether digestibilities are similar for the 3 species or whether different ingredient values need to be considered for each species. This has hardly been studied. It is known, however, that the development of the digestive tract during growth is different between broilers and waterfowl (Jamroz et al., 2001, 2002, 2004), which might affect AA digestibility. Jamroz et al. (2001) found that at the age of 6 wk, the mean digestibility of AA in broilers, ducks, and geese was 76, 69, and 56%, respectively.
Digestibility values for AA are affected to a variable extent by AA contained in the secreted and nonreabsorbed endogenous protein. The basal endogenous protein is commonly assumed to depend mainly on dry matter intake, although results by Ravindran and Hendriks (2004) suggest that this is not the case in broilers. The specific endogenous protein is affected by the amount and nature of the feed under study (i.e., its digestibility, fiber content, nonstarch polysaccharide content and digesta viscosity, and other antinutritional factors (Angkanaporn et al., 1997; Dänicke et al., 2000; Souffrant, 2001). Comparative studies on the protein value of ingredients based on AA digestibility depend, therefore, on an adequate consideration of endogenous losses. However, attempts to measure endogenous AA loss lead to highly variable results (Donkoh and Moughan, 1999) with poorly identified reasons for this variation. Rutherfurd et al. (2004) pointed out a relatively large amount of variation between endogenous flows determined in different laboratories and within the same laboratory. Therefore, an approach that does not depend on a separate determination of endogenous losses appears advantageous to feed evaluation. As an alternative, without the need for a separate measure of endogenous AA loss, digestibility of AA in broilers was studied by linear regression analysis (Short et al., 1999; Rodehutscord et al., 2004; Kluth et al., 2005a).
It is unclear whether the above-mentioned differences in AA digestibility among species can be explained by differences in the endogenous AA loss among species or whether they are an actual difference in the birds’ ability to digest feed protein. For this reason, the objective of the present study was to compare AA digestibility in broilers, turkeys, and Pekin ducks of the same age by applying a linear regression approach and to find out whether the values determined in 1 species can be applied to another. Solvent-extracted soybean meal (SBM) and solvent-extracted rapeseed meal (RSM) were used as the studied ingredients.
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MATERIALS AND METHODS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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Five diets were mixed, and the same diets were used in all experiments. The basal diet (BD; Table 1
) was based mainly on corn, wheat gluten, and cornstarch. A CP level of about 15% was chosen for the BD. This was intended as a compromise to avoid a severely reduced intake of the BD as well as to provide a wide range for supplementing the test proteins. In the 4 other diets, SBM or RSM was included at levels of either 150 or 300 g/kg at the expense of cornstarch. Hence, the variation in the diet’s AA content originated from the respective oilseed meal only. Diets contained TiO2 as an indigestible marker at a level of 5 g/kg. With the exception of the variable ingredients (cornstarch, SBM, RSM), all the other ingredients were combined in 1 batch to ensure uniformity of the mix. This mix was divided into 5 portions. Cornstarch, SBM, and RSM were then added in the respective amounts. Diets were remixed and subsequently pelleted through a 3-mm die without steam. Analyzed concentrations of proximate nutrients and AA are given in Table 2 for the diets and the 2 oilseed meals.
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Three experiments were run consequently, 1 with each species: male broiler chickens (Ross 308, Geflü gelhof Möckern, Germany), male White Pekin ducks (Stolle Seddin Vital, Seddiner Zuchtund Mastenten GmbH, Wriezen, Germany), and male turkeys (British United Turkeys, Big 6, Moorgut Kartzfehn, Bösel, Germany). Experiments were approved by the animal welfare authorities in accordance with the German Animal Welfare Regulations. Four hundred fifty hatchlings from each species were kept in groups of 15 in floor pens with a mixed bedding of straw chaft and wood shavings and temperatures and illumination according to the recommendations given for the respective species. Birds were fed a starter feed specific for each species containing 12.6 (broilers), 11.4 (turkeys), and 11.4 (ducks) MJ of ME/kg and 230 (broilers), 290 (turkeys), and 210 (ducks) g of CP/kg of diet for 1 to 14 d posthatch. Birds had free access to drinking water from nipple drinkers with attached cups and feed from 1 trough per pen.
On d 14, the number of birds per pen was reduced to 12, based on BW uniformity. The mean BW at this stage was 517 (broilers), 362 (turkeys), and 729 g (ducks). Each of the 5 experimental diets was then randomly allocated to 6 pens, and diets were offered ad libitum for 7 d. At the end of this period, all birds were asphyxiated with CO2, and the intestine section beginning at Meckel’s diverticulum up to 2 cm anterior to the ileocecocolonic junction was immediately removed. Only the terminal two-thirds of this section were used for digesta sampling, as suggested by Kluth et al. (2005b). The gut content was flushed out with distilled water. Contents were pooled within the 12 birds of 1 pen, immediately frozen at –18°C, freeze-dried, and ground through a 0.5-mm screen for later chemical analyses. The birds’ BW was determined at the beginning and end of the experimental period, and feed consumption was measured for each pen.
Chemical Analyses
Diets were analyzed for DM, ash, CP, crude fat, crude fiber, AA, gross energy (GE), and TiO2. Freeze-dried digesta samples were analyzed for CP, AA, energy, and TiO2. Crude nutrients were determined according to the official methods in Germany (Naumann and Bassler, 1976). The AA analysis also followed standard procedures, and details were given by Timmler and Rodehutscord (2003). After an oxidation step, samples were hydrolyzed in 6 N HCl. Norleucine was used as the external standard. Tryptophan, His, and Tyr were not determined. Separation of AA was done with an AA analyzer (Eppendorf LC 3000, Eppendorf, Hamburg, Germany) using different buffer solutions and ninhydrin. The TiO2 content was determined by the method described by Brandt and Allam (1987). Energy was determined with a bomb calorimeter (IKA-Calorimeter C7000 isoperibolic, Janke & Kunkel IKA Analysentechnik, Staufen, Germany).
Calculations and Statistical Analyses
The digestibility (DC) of AA for each diet (DCAA Diet) was calculated according to the following equation:
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where TiO2 Diet and TiO2 Digesta = respective concentrations of TiO2 in the diet and digesta samples (g/kg); and AADiet and AADigesta = respective concentrations of the AA in the diet and digesta samples (g/kg)
To calculate the DC of CP and GE, the same equation was used with the respective concentrations of CP (g/ kg) or GE (MJ/kg) in place of AA concentrations.
The partial DC of AA from the 2 oilseed meals was assessed by multiple linear regression analysis using data on daily intakes and digested amounts, as described by Kluth et al. (2005a). Daily intakes of AA and CP were calculated separately for the BD and oilseed meals. The total daily intake was calculated as feed intake (g/d) x analyzed AA (or CP) concentration in the diet (mg/g). Amino acid (or CP) intake attributable to the BD could be computed as feed intake (g/d) x analyzed AA (or CP) concentration in the BD (mg/g). Because SBM and RSM were included in the diets at the expense of starch, inclusion had no effect on the concentration of AA from the BD in the total diet. Daily intake of AA from the supplemented meals was calculated as the difference between the total intake and intake attributable to the BD. The quantity of AA digested up to the terminal ileum was calculated as AA intake (mg/d) x DCAA Diet/100. The following model was applied to simultaneously determine the partial DC of AA and CP from the 2 oilseed meals (Kluth et al., 2005a):
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where y = daily amount of AA (or CP) digested; 
= intercept; ßb = DC of AA (or CP) originating from the BD; ib = daily intake of AA (or CP) with BD; ßi = DC of AA (or CP) from oilseed meal i (SBM or RSM); and i(si) = daily intake of AA (or CP) from oilseed meal i (SBM or RSM).
The assumption of linearity between the intake and digested amounts of AA was based on previous findings (Short et al., 1999; Rodehutscord et al., 2004) and was confirmed in this study.
The data were analyzed according to a completely randomized block design using the GLM procedure of the statistical software package SAS (Version 8.2, SAS Institute Inc., Cary, NC). Differences in DC between the 2 oilseed meals were tested for significance using the ESTIMATE statement (t-test). Linear regressions were calculated using GraphPad Prism 4.02 (GraphPad Software, Inc. San Diego, CA). Data for the DC of GE from the complete diets were subjected to 2-factorial ANOVA. Because of a significant interaction between the diet effect and the species effect, the effect of diet on the DC of GE was tested for each species separately using Tukey’s test and a level of significance of P 
0.05.
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RESULTS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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The DC determined for the diets varied from 44 to 94% for individual AA (Table 3). Among the analyzed essential AA, Met had the highest and Thr had the lowest DC, irrespective of the species. For CP, a high level of DC was determined in broilers for all diets. The DC of individual AA (except Glu) in turkeys was higher when the oilseed meals were included in the diet. In broilers and ducks, the level of AA DC was similar and unchanged by oilseed meal supplementation.
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. Partial DC for essential AA from the oilseed meals varied from 92% (Met, RSM, broilers) to 62% (Val, RSM, ducks; Table 4). Within species, partial DC was not significantly different between SBM and RSM for broilers and turkeys. In ducks, significant differences were detected for Arg, Met, and Phe. Partial DC for individual AA differed among species. The level of partial DC of AA was lower in ducks than in the other 2 species, which showed similar partial DC values without significant differences. For SBM, significantly higher DC was detected for Lys, Met, Thr, and Val in broilers than in ducks. All AA from RSM, with the exception of Phe and Ser, tended to be less digested in ducks than in broilers. The ranking of individual AA in DC was relatively similar between broilers and turkeys (Table 5). The ranking of the values for ducks differed from the other 2 species but still showed similarities. For example, out of the 5 AA with the highest DC in broilers and turkeys, 4 were present in the group of the 5 highest digestible AA in ducks.
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). The replacement of cornstarch with oilseed meal caused a reduction in the GE DC of the diet. This effect was significant in broilers and ducks on the highest level of inclusion of SBM or RSM.
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DISCUSSION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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), it can be concluded that basal endogenous AA losses were not the primary reason for the differences found in digestibilities between broilers and ducks. Differences in specific endogenous losses among the species may be relevant, but these could not be considered with the chosen approach. The studies by Jamroz et al. (2004) indicate that the differences in the development of the digestive tract might be the cause of the species’ differences in DC. They found that the relative length of the small intestine (in relation to BW0.67) is higher in broilers than in ducks. Estimates made from Figure 2 and Table 2 of Applegate et al. (2005) indicate that the length of jejunum + ileum in relation to BW, measured on d 7 posthatch, is greater in turkeys than in ducks. In the same study, however, Applegate et al. (2005) found a higher relative mass of jejunum + ileum in ducks than in turkeys and viewed this difference as a reason for the higher growth rate in ducks. Based on our findings, differences in AA DC should not be considered a cause of the differences in the 3 species’ growth rate because ducks had the lowest DC. The overall level of AA DC in ducks was higher in the studies of Adeola (2005) and Nyachoti et al. (2004) than in the present study. However, these authors used older ducks and a different assay; they calculated the DC by excreta analyses. The effects of postileal fermentation and the feeding level on AA DC account, in major part, for the differences between the present study and those of Adeola (2005) and Nyachoti et al. (2004).
The average DC in 28- to 42-d-old broilers of the AA Arg, Ile, Leu, Lys, Met, Phe, Thr, and Val from SBM was 82 (Pérez et al., 1993), 84 (Ravindran et al., 1999), and 88% (Bryden and Li, 2004). The corresponding average from the present broiler study was 81%. On the other hand, the average DC of the indicated AA for RSM was higher in the present study (82%) than the 78% value reported by Ravindran et al. (1999) and equal to the value reported by Bryden and Li (2004). One may consider these differences as indicative of differences in DC among different origins of the same raw material. However, as long as the methodological details of prececal DC studies are poorly standardized (age of birds, CP level in the diet, consideration of endogenous AA loss, length of the sampled intestine section, etc.), the results of different studies will remain difficult to compare in regard to the ingredient under study (Rodehutscord and Mosenthin, 2005). When data for RSM obtained with broilers and a similar experimental approach were compared [as in the present study and Rodehutscord et al. (2004)], the DC was equal or similar (no more than 2 percentage units difference) for 9 out of 14 analyzed AA. Larger differences were noted for Leu, Met, Phe, Thr (each 4 percentage units), and cystine (8 percentage units). Kluth et al. (2005a) used the same regression approach to study differences in DC among 4 cultivars of Pisum sativum and found that 1 variety had significantly lower DC than the other 3. Pea lines with a high activity of trypsin inhibitors had lower AA DC than lines with low activity (Wiseman et al., 2003). There is some evidence, therefore, that AA digestibilities vary not only among different feedstuffs, but also among different batches of the same feedstuff.
In 4-wk-old turkeys, Palander et al. (2004) found differences in the CP DC between SBM (80%) and RSM (66%). In the present study, a lower CP DC was also found for RSM (78%) than for SBM (85%), although this was statistically insignificant (Table 4). Digestibilities for AA in turkeys were reported from studies investigating the effects of supplementing the enzyme phytase (Yi et al., 1996; Wendt and Rodehutscord, 2004). The range in AA DC reported in these studies was similar to the present study.
It can be concluded that there are differences in AA DC among poultry species. The underlying mechanisms and reasons still require clarification. However, the application of data obtained with broilers in feed formulation for turkeys and ducks is not justified. Ducks digested AA from both oilseed meals to a lesser extent than broilers and turkeys. Data indicated that the magnitude and direction of differences in AA DC between broilers and turkeys depends on the raw material. The ranking in DC of individual AA was very similar between broilers and turkeys, but differences exist between ducks and the 2 other species.
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FOOTNOTES |
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Received for publication March 26, 2006. Accepted for publication June 17, 2006.
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REFERENCES |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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Angkanaporn, K., V. Ravindran, Y. Mollah, and W. L. Bryden. 1997. Evaluation of homoarginine as a marker for the determination of endogenous amino acid concentrations in poultry excreta. Br. Poult. Sci. 38:577–585.[Web of Science][Medline]
Applegate, T. J., D. M. Karcher, and M. S. Lilburn. 2005. Comparative development of the small intestine in the turkey poult and Pekin duckling. Poult. Sci. 84:426–431.
Bielorai, R., B. Iosif, and H. Neumark. 1985. Nitrogen absorption and endogenous nitrogen along the intestinal tract of chicks. J. Nutr. 115:568–572.
Brandt, M., and S. M. Allam. 1987. Analytik von TiO2 im Darmin-halt und Kot nach Kjeldahlaufschluß. Arch. Anim. Nutr. 37:453–454.
Bryden, W. L., and X. Li. 2004. Utilisation of digestible amino acids by broilers. Report publication no. 04/030. Rural Ind. Res. Dev. Corp., Barton, ACT, Australia.
Dänicke, S., W. Böttcher, H. Jeroch, J. Thielebein, and O. Simon. 2000. Replacement of soybean oil with tallow in rye-based diets without xylanase increases protein synthesis in small intestine of broilers. J. Nutr. 130:827–834.
Donkoh, A., and P. J. Moughan. 1999. Endogenous ileal nitrogen and amino acid flows in the growing pig receiving a protein-free diet and diets containing enzymically hydrolysed casein or graded levels of meat and bone meal. Anim. Sci. 68:511–518.
Gruhn, K., and R. Zander. 1989. Untersuchungen zum Einfluß gestaffelter Gaben an Sojaextraktionsschrot auf die scheinbare Verdaulichkeit der Rohnährstoffe und Aminosäuren bei kolostomierten Legehennen. Arch. Anim. Nutr. 39:123–130.
Huang, K., V. Ravindran, L. I. Hew, and W. L. Bryden. 2000. Ileal protein digestibility of eight feed ingredients determined with broilers and layers. Proc. Aust. Poult. Sci. Symp. 12:198. (Abstr.)
Jamroz, D., K. Jakobsen, J. Orda, J. Skorupinska, and A. Wiliczkiewicz. 2001. Development of gastrointestinal tract and digestibility of dietary fibre and amino acid in young chickens, ducks and geese fed diets with high amounts of barley. Comp. Biochem. Physiol. A Mol. Integr. Physiol. 130:643–652.[Medline]
Jamroz, D., T. Wertelecki, A. Wiliczkiewicz, J. Orda, and J. Skorupinska. 2004. Dynamics of yolk sac resorption and post-hatching development of the gastrointestinal tract in chickens, ducks and geese. J. Anim. Physiol. Anim. Nutr. (Berl.) 88:239–250.[Medline]
Jamroz, D., A. Wiliczkiewicz, J. Orda, T. Wertelecki, and J. Skorupinska. 2002. Aspects of development of digestive activity of intestine in young chickens, ducks and geese. J. Anim. Physiol. Anim. Nutr. (Berl.) 86:353–366.[Medline]
Johns, D. C., C. K. Low, and K. A. James. 1986. Comparison of amino acid digestibility using the ileal digesta from growing chickens and cannulated adult cockerels. Br. Poult. Sci. 27:679–685.[Web of Science][Medline]
Kadim, I. T., P. J. Moughan, and V. Ravindran. 2002. Ileal amino acid digestibility assay for the growing meat chicken – comparison of ileal and excreta amino acid digestibility in the chicken. Br. Poult. Sci. 44:588–597.
Kluth, H., M. Mantei, C. Elwert, and M. Rodehutscord. 2005a. Variation in precaecal amino acid and energy digestibility between pea (Pisum sativum) cultivars determined using a linear regression approach. Br. Poult. Sci. 46:325–332.[Web of Science][Medline]
Kluth, H., K. Mehlhorn, and M. Rodehutscord. 2005b. Studies on the intestine section to be sampled in broiler studies on precaecal amino acid digestibility. Arch. Anim. Nutr. 59:271–279.[Web of Science][Medline]
Martin, E. A., J. V. Nolan, Z. Nitsan, and D. J. Farrell. 1998. Strategies to improve the nutritive value of rice bran in poultry diets. IV. Effects of addition of fish meal and a microbial phytase to duckling diets on bird performance and amino acid digestibility. Br. Poult. Sci. 39:612–621.[Web of Science][Medline]
Mitchell, H. H., and M. H. Bert. 1954. The determination of metabolic fecal nitrogen. J. Nutr. 52:483–497.
Naumann, C., and R. Bassler. 1976. Die chemische Untersuchung von Futtermitteln. VDLUFA-Methodenbuch, Vol. 3. Loose leaflet collection with supplements from 1983, 1988, and 1993. Verband Deutscher Landwirtschaftlicher Untersuchungs- und Forschungsanstalten, ed. VDLUFA-Verlag, Darmstadt, Germany.
Nyachoti, C. M., E. M. Onyango, O. F. Omogbenigun, and O. Adeola. 2004. Nutritional evaluation of peas for ducks. J. Sci. Food Agric. 84:474–480.
Palander, S., M. Näsi, and I. Ala-Fossi. 2004. Rapeseed and soybean products as protein sources for growing turkeys of different ages. Br. Poult. Sci. 45:664–671.[Web of Science][Medline]
Pérez, L., I. Fernández-Figares, R. Nieto, J. F. Aguilera, and C. Prieto. 1993. Amino acid ileal digestibility of some grain legume seeds in growing chickens. Anim. Prod. 56:261–267.
Ravindran, V., and W. H. Hendriks. 2004. Recovery and composition of endogenous protein collected at the terminal ileum as influenced by the age of broiler chickens. Aust. J. Agric. Res. 55:705–709.
Ravindran, V., L. I. Hew, and W. L. Bryden. 1998. Influence of guanidination on apparent ileal amino acid digestibility in some protein sources for broilers. Poult. Sci. 77:873–877.
Ravindran, V., L. I. Hew, G. Ravindran, and W. L. Bryden. 1999. A comparison of ileal digesta and excreta analysis for the determination of amino acid digestibility in food ingredients for poultry. Br. Poult. Sci. 40:266–274.[Web of Science][Medline]
Rodehutscord, M., M. Kapocius, R. Timmler, and A. Dieckmann. 2004. Linear regression approach to study amino acid digestibility in broiler chickens. Br. Poult. Sci. 45:85–92.[Web of Science][Medline]
Rodehutscord, M., and R. Mosenthin. 2005. Precaecal digestibility in feedstuff evaluation for poultry and pigs. Proc. Soc. Nutr. Physiol. 14:174–180.
Rutherfurd, S. M., T. K. Chung, P. C. H. Morel, and P. J. Moughan. 2004. Effect of microbial phytase on ileal digestibility of phytate phosphorus, total phosphorus, and amino acids in a low-phosphorus diet for broilers. Poult. Sci. 83:61–68.
Short, F. J., J. Wiseman, and K. N. Boorman. 1999. Application of a method to determine ileal digestibility in broilers of amino acids in wheat. Anim. Feed Sci. Technol. 79:195–209.
Souffrant, W. B. 2001. Effect of dietary fibre on ileal digestibility and endogenous nitrogen losses in the pig. Anim. Feed Sci. Technol. 90:93–102.
Ten Doeschate, R. A. H. M., C. W. Scheele, V. V. A. M. Schreurs, and J. D. Van Der Klis. 1993. Digestibility studies in broiler chickens: Influence of genotype, age, sex and method of determination. Br. Poult. Sci. 34:131–146.
Timmler, R., and M. Rodehutscord. 2003. Dose-response relationships for valine in the growing White Pekin duck. Poult. Sci. 82:1755–1762.
Wendt, P., and M. Rodehutscord. 2004. Studies on the efficiency of two phytase preparations in Pekin ducks. Pages 109–111 in Proc. 8th Conf. Pig Poult. Nutr. Inst. Ernährungswissenschaften, Univ. Halle-Wittenberg, Halle (Salle), Germany.
Wiseman, J., W. Al-Mazooqi, T. Welham, and C. Domoney. 2003. The apparent ileal digestibility, determined with young broilers, of amino acids in near-isogenic lines of peas (Pisum sativum L.) differing in trypsin inhibitor activity. J. Sci. Food Agric. 83:644–651.
Yi, Z., E. T. Kornegay, and D. M. Denbow. 1996. Effect of microbial phytase on nitrogen and amino acid digestibility and nitrogen retention of turkey poults fed corn-soybean meal diets. Poult. Sci. 75:979–990.[Web of Science][Medline]
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