ORIGINAL ARTICLES
Prediction of basal endogenous losses of amino acids based on body weight and feed intake in pigs fed nitrogen-free diets¤
Predicción de las pérdidas endógenas basales de aminoácidos a partir del peso corporal y consumo de alimento en cerdos sometidos a dietas libres de nitrógeno
Predição das perdas basais endógenas de aminoácidos a partir do peso corporal e do consumo de alimento em porcos submetidos a dietas livres de nitrogênio
]]> Chan Sol Park, Animal Science, BA; Sei In Oh, Animal Science, BA; Beob Gyun Kim*, Animal Science, PhD.
* Corresponding author: BG Kim. Department of Animal Science and Technology, Konkuk University, Seoul 143-701, Korea. Tel +82-2-2049-6255. Email: bgkim@konkuk.ac.kr
Department of Animal Science and Technology, Konkuk University, Seoul 143-701, Republic of Korea.
(Received: January 29, 2013; accepted: May 27, 2013)
Summary
Background: accurate estimations of basal endogenous losses (BEL) of amino acids (AA) are important for the calculation of standardized ileal digestibility values. Objectives: to address the influence of body weight (BW) and feed intake on BEL of crude protein (CP) and AA and to develop prediction equations for BEL of CP and AA in pigs fed nitrogen-free diets. Methods: based on data derived from 34 research papers, prediction equations for BEL of CP and AA were generated using BW and feed intake per maintenance feed intake (FI:MFI) based on energy concentration as independent variables. Results: initial BW (IBW) and FI:MFI ranged from 13.8 to 109.8 kg and from 1 to 5, respectively. Mean values for BEL of CP, Lys, Met, Thr, and Trp were 17.2 (CV = 50.9%), 0.42 (CV = 56.0%), 0.14 (CV = 80.8%), 0.55 (CV = 41.3%), and 0.14 (CV = 57.5%) g/kg dry matter intake (DMI), respectively. The FI:MFI was negatively correlated with BEL of CP and AA except Met (r < –0.39; p<0.05). Prediction equations for estimating the BEL of CP and AA (g/kg DMI) developed were: BEL of CP = 47.5 – (8.09 × 10–2 × IBW) – (8.83 × FI:MFI) with R2 = 0.32 and p = 0.011; BEL of Lys = 0.979 – (1.00 × 10–3 × IBW) – (0.174 × FI:MFI) with R2 = 0.24 and p = 0.014; BEL of Thr = 1.09 – (1.82 × 10–3 × IBW) – (0.153 × FI:MFI) with R2 = 0.28 and p = 0.007; and BEL of Trp = 0.552 – (1.11 × 10–3 × IBW) – (0.120 × FI:MFI) with R2 = 0.47 and p = 0.002. Conclusion: based on the equations above, IBW and FI:MFI clearly decrease BEL of CP and AA. The equations provided in this paper may be used for estimating BEL of CP and AA.
Key words: modeling, standardized ileal digestibility, swine.
Resumen
]]> Antecedentes: la estimación precisa de las pérdidas endógenas basales (BEL) de aminoácidos (AA) es importante para calcular los valores de la digestibilidad ileal estandarizada. Objetivos: establecer la influencia del peso corporal y el consumo de alimento sobre las BEL de proteína cruda (CP) y AA, y desarrollar ecuaciones de predicción para las BEL de CP y AA en cerdos alimentados con dietas libres de nitrógeno. Métodos: basados en información proveniente de 34 artículos científicos, fueron generadas ecuaciones de predicción para las BEL de CP y AA usando el peso corporal (BW) y el consumo de alimento por consumo de mantenimiento (FI:MFI) con base en la concentración de energía como variables independientes. Resultados: BW y FI:MFI variaron de 13,8 a 109,8 kg y de 1 a 5, respectivamente. Los valores de la media para BEL de CP, Lys, Met, Thr, y Trp fueron 17,2 (CV = 50,9%), 0,42 (CV = 56,0%), 0,14 (CV = 80,8%), 0,55 (CV = 41,3%), y 0,14 (CV = 57,5%) g/kg de consumo de materia seca (DMI), respectivamente. El FI:MFI se correlacionó negativamente con las BEL de CP y AA excepto con la Met (r < –0,39; p<0,05). Las ecuaciones de predicción para estimar las BEL de la CP y AA (g/kg DMI) desarrolladas fueron: BEL de CP = 47,5 – (8,09 × 10–2 × IBW) – (8,83 × FI:MFI) con un R2 = 0,32 y un p = 0,011; BEL de Lys = 0,979 – (1,00 × 10–3 × IBW) – (0,174 × FI:MFI) con un R2 = 0,24 y un p = 0,014; BEL de Thr = 1,09 – (1,82 × 10–3 × IBW) – (0,153 × FI:MFI) con un R2 = 0,28 y un p = 0,007; y las BEL de Trp = 0,552 – (1,11 × 10–3 × IBW) – (0,120 × FI:MFI) con un R2 = 0,47 y un p = 0,002. Conclusión: con base en las anteriores ecuaciones, el IBW y el FI:MFI claramente redujeron las BEL de CP y AA. Las ecuaciones suministradas en este artículo pueden ser utilizadas para estimar las BEL de CP y AA.Palabras clave: digestibilidad ileal estandarizada, modelación, porcinos.
Resumo
Antecedentes: a estimação precisa das perdas endógenas basais (BEL) de aminoácidos (AA) é importante para calcular os valores da digestibilidade ileal padronizada. Objetivos: estabelecer a influencia do peso corporal e do consumo de alimento sobre as BEL da proteína bruta (CP) e AA, e desenvolver equações de predição para as BEL da CP e AA em porcos alimentados com dietas livres de nitrogênio. Métodos: baseados em informação proveniente de 34 artigos científicos, foram geradas equações de predição para as BEL da CP e AA usando o peso corporal (BW) e o consumo de alimento por consumo de manutenção (FI:MFI) com base na concentração de energia como variáveis independentes. Resultados: BW e FI:MFI variaram de 13,8 a 109,8 kg e de 1 a 5, respectivamente. Os valores da média para BEL da CP, Lys, Met, Thr, e Trp foram 17,2 (CV = 50,9%), 0,42 (CV = 56,0%), 0,14 (CV = 80,8%), 0,55 (CV = 41,3%), e 0,14 (CV = 57,5%) g/kg de consumo de matéria seca (DMI), respectivamente. O FI:MFI teve correlação negativa com as BEL da CP e AA exceto com a Met (r < –0,39; p<0,05). As equações de predição para estimar as BEL da CP e AA (g/kg DMI) desenvolvidas foram: BEL da CP = 47,5 – (8,09 × 10–2 × IBW) – (8,83 × FI:MFI) com um R2 = 0,32 e um p = 0,011; BEL de Lys = 0,979 – (1,00 × 10–3 × IBW) – (0,174 × FI:MFI) com um R2 = 0,24 e um p = 0,014; BEL de Thr = 1,09 – (1,82 × 10–3 × IBW) – (0,153 × FI:MFI) com um R2 = 0,28 e um p = 0,007; e as BEL de Trp = 0,552 – (1,11 × 10–3 × IBW) – (0,120 × FI:MFI) com um R2 = 0,47 e um p = 0,002. Conclusão: Com base nas anteriores equações, o IBW e o FI:MFI claramente diminuíram as BEL da CP e AA. As equações fornecidas neste artigo podem ser utilizadas para estimar as BEL do CP e AA.
Palavras chave: digestibilidade ileal padronizada, modelação, porcinos.
Introduction
An accurate determination of the concentration of digestible crude protein (CP) and amino acids (AA) is the major factor to take into consideration in determining standardized ileal digestibility (SID) values of feed ingredients. The SID is widely used in expressing AA requirements and AA contents in feedstuffs for swine diet formulation (Sauvant et al., 2004; Stein et al., 2007; NRC, 2012). For calculating SID of CP and AA, basal endogenous losses (BEL) of CP and AA generally expressed as g per kg of dry matter intake (DMI) should be accurately estimated.
The mean values for the BEL of CP and AA in the literature have been reported (Jansman et al., 2002; NRC, 2012). However, the BEL values of CP and AA largely vary among animal experiments (Viljoen et al., 1998; Pahm et al., 2008; Kim et al., 2009) potentially due to the differences in a) body weight (BW; Høøk Presto et al., 2010), b) structure of dietary fiber (Leterme and Théwis, 2004), and c) feed intake level (Hess and Sève, 1999; Stein et al., 1999).
]]> Although the factors affecting the BEL of CP and AA have been studied and the mean BEL values have been reported (Jansman et al., 2002; NRC, 2012), prediction models for estimating BEL of CP and AA are currently not available. Prediction equations for BEL of CP and AA may be used for the calculation of SID of CP and AA values in feedstuffs without a nitrogen (N)-free diet group, and can also help accurate estimations of maintenance AA for the determination of AA requirements in an approach used in NRC (2012). Therefore, the objective of the present work was to develop prediction equations for BEL of CP and AA in pigs fed N-free diets using data from the literature.
Materials and methods
The database
Data were derived from 34 research papers in refereed journals that used pigs cannulated at the distal ileum and fed N-free diets to measure BEL of CP and AA. The database consisted of BEL of CP and AA (g/kg DMI, Table 1), BW (kg), feed intake level, experimental period (d), and fiber content (%) in the N-free diet.
Final BW was calculated based on NRC (2012) and experimental periods. Mean BW was calculated using the initial BW (IBW) and final BW. Feed intake per maintenance feed intake (FI:MFI) based on energy concentration was calculated to remove the contribution of BW on feed intake. Experimental periods were calculated using the experimental design and duration of adaptation and collection periods.
Statistical analysis
Association among variables expressed as correlation coefficients among IBW, FI:MFI, BEL of CP, and BEL of AA were determined by CORR procedure of SAS (SAS Inst. Inc., Cary, NC). Prediction equations for BEL of CP and AA were generated by PROC REG of SAS using BEL of CP and AA as dependent variables and IBW, the square of IBW, final BW, the square of final BW, mean BW, the square of mean BW, FI:MFI, experimental period, and dietary fiber content as independent variables. Based on root mean square error (RMSE), Mallows statistic [C(p)], regression coefficient (R2), and p-value, redundant independent variables were excluded. Observations that had a Cook's distance value greater than 0.30 were excluded.
Results
]]> The IBW in the studied dataset ranged from 13.8 to 109.8 kg and mean values for BEL of CP and AA (g/kg DMI) are presented in table 1. The BEL of Met had the greatest variability among experiments (0.03 to 0.64 g/kg DMI, CV = 80.8%) and the BEL of Thr had the lowest variability (0.12 to 1.53 g/kg DMI, CV = 41.3%). The range for BEL of CP was 7.94 to 48.6 g/kg DMI with CV of 50.9%.The BEL of CP was positively correlated with all indispensable AA (r > 0.35; p<0.05; Table 2). The FI:MFI was negatively correlated with BEL of CP and AA except Met (r < –0.39; p<0.05). Mean BW, final BW, and concentration of dietary fiber were not correlated with BEL of CP and AA (data not shown).
Prediction equations for estimating the BEL of CP and AA (g/kg DMI) developed are provided in table 3: BEL of CP = 47.5 – (8.09 × 10–2 × IBW) – (8.83 × FI:MFI) with R2 = 0.32 and p = 0.011; BEL of Lys = 0.979 – (1.00 × 10–3 × IBW) – (0.174 × FI:MFI) with R2 = 0.24 and p = 0.014; BEL of Thr = 1.09 – (1.82 × 10–3 × IBW) – (0.153 × FI:MFI) with R2 = 0.28 and p = 0.007; and BEL of Trp = 0.552 – (1.11 × 10–3 × IBW) – (0.120 × FI:MFI) with R2 = 0.47 and p = 0.002.
Discussion
To measure ileal endogenous flow of CP and AA, researchers used the N-free diet method, highly digestible N sources, or regression techniques (Jansman et al., 2002; Stein et al., 2007). However, the values for BEL of CP and AA were different among experimental methods (Jansman et al., 2002). In the present work, we used data from experiments employing N-free diets.
All mean values for BEL of CP and AA were fairly comparable to the data in NRC (2012) and had relatively high variability (Table 1). The ratios of BEL of AA to BEL of Lys in this work are fairly in agreement with previously reported data (Jansman et al., 2002; NRC, 2012). Høøk Presto et al. (2010) also suggested that AA composition (expressed in ratio of CP) of endogenous flow was quite consistent.
Hess and Sève (1999) suggested that BEL of CP and some AA (g/kg DMI) increased when feeding level was decreased in 45 kg pigs but not in 77 kg pigs. In a study by Moter and Stein (2004), the negative association between feeding level and BEL of CP and AA (g/kg DMI) was very clearly demonstrated. The clarity of response in the later study appears to be due to the larger range of feed intake, the higher number of observations, or both compared with the study by Hess and Sève (1999). Thus, feeding levels in a wide range apparently affect BEL of CP and AA (g/kg DMI). However, feeding level is very positively correlated with BW. ''Feed intake per maintenance feed intake based on energy concentration'' employed in the present work represents the amount of feed intake independent from IBW. In many AA digestibility experiments, feed allowance was 3 times the maintenance energy requirements (i.e., 3 FI:MFI). Because a heavier pig needs greater energy quantity for maintenance than a lighter pig, feed allowance for a heavier pig is more than for a lighter pig. In the present work, we tried to remove the effect of BW from the effects of feed intake on BEL of CP and AA by using the concept of FI:MFI. The lack of association between BW and BEL of CP and AA may be due to the large variation in experimental periods among observations or by the potential carryover effect of experimental diets consumed before the N-free diet.
]]> Prediction equations for estimating BEL of CP and AA (g/kg DMI) were determined by IBW and FI:MFI (Table 3). The square of IBW, final BW, the square of final BW, mean BW, the square of mean BW, experimental period and dietary fiber concentration were also used to generate prediction equations, but these variables were not included in the final model due to the lack of significance. Thus, IBW and FI:MFI were used in the prediction equations. Except prediction equations for BEL of Arg, Leu, and Met, p-values of all equations were less than 0.05. Prediction equations for BEL of Trp had the greatest R2 and lowest p-value (R2 = 0.47; p = 0.002, respectively). The R2-values of other prediction equations were relatively low, which may be due to the large variation in the estimated values among experiments and the error associated with AA and index (e.g., Cr) analysis or ileal digesta sampling procedure. Initial BW and FI:MFI were negatively correlated with BEL of CP and most indispensable AA in agreement with previous studies (Hess and Sève, 1999; Moter and Stein, 2004; Høøk Presto et al., 2010).Basal endogenous losses of CP and AA may be estimated using prediction equations proposed in this study. More research is needed to confirm and improve the accuracy of the prediction equations.
Notas
¤To cite this article: CS Park, SI Oh, BG Kim. Prediction of basal endogenous losses of amino acids based on body weight and feed intake in pigs fed nitrogen-free diets. Rev Colomb Cienc Pecu 2013; 26:186-192.
Acknowledgements
The authors are grateful for the support by Rural Development Administration (Suwon, Republic of Korea; PJ907038).
]]> References
Almeida FN, Petersen GI, Stein HH. Digestibility of amino acids in corn, corn coproducts, and bakery meal fed to growing pigs. J Anim Sci 2011; 89:4109-115. [ Links ]
Baker KM, Stein HH. Amino acid digestibility and concentration of digestible and metabolizable energy in soybean meal produced from conventional, high-protein, or lowoligosaccharide varieties of soybeans and fed to growing pigs. J Anim Sci 2009; 87:2282-290. [ Links ]
Bohlke RA, Thaler RC, Stein HH. Calcium, phosphorus, and amino acid digestibility in low-phytate corn, normal corn, and soybean meal by growing pigs. J Anim Sci 2005; 83:2396-403. [ Links ]
Cervantes-Pahm SK, Stein HH. Effect of dietary soybean oil and soybean protein concentration on the concentration of digestible amino acids in soybean products fed to growing pigs. J Anim Sci 2008; 86:1841-849. [ Links ]
Chung TK, Baker DH. Apparent and true amino acid digestibility of a crystalline amino acid mixture and of casein: comparison of values obtained with ileal-cannulated pigs and cecectomized cockerels. J Anim Sci 1992; 70:3781-790. [ Links ]
Cozannet P, Primot Y, Gady C, Métayer JP, Callu P, Lessire M, Skiba F, Noblet J. Ileal digestibility of amino acids in wheat distillers dried grains with solubles for pigs. Anim Feed Sci Technol 2010; 158:177-86. [ Links ]
González-Vega JC, Kim BG, Htoo JK, Lemme A, Stein HH. Amino acid digestibility in heated soybean meal fed to growing pigs. J Anim Sci 2011; 89:3617-625. [ Links ]
González-Vega JC, Stein HH. Amino acid digestibility in canola, cottonseed, and sunflower products fed to finishing pigs. J Anim Sci 2012; 90:4391-400. [ Links ]
Gottlob RO, DeRouchey JM, Tokach MD, Goodband RD, Dritz SS, Nelssen JL, Hastad CW, Knabe DA. Amino acid and energy digestibility of protein sources for growing pigs. J Anim Sci 2006; 84:1396-402. [ Links ]
Hess V, Sève B. Effects of body weight and feed intake level on basal ileal endogenous losses in growing pigs. J Anim Sci 1999; 77:3281-288. [ Links ]
Høøk Presto M, Lyberg K, Lindberg JE. Effect of body weight on ileal endogenous nitrogen and amino acid loss in PVTCcannulated pigs. Livest Sci 2010; 134:18-20. [ Links ]
Jacela JY, DeRouchey JM, Dritz SS, Tokach MD, Goodband RD, Nelssen JL, Sulabo RC, Thaler RC, Brandts L, Little DE, Prusa KJ. Amino acid digestibility and energy content of deoiled (solvent-extracted) corn distillers dried grains with solubles for swine and effects on growth performance and carcass characteristics. J Anim Sci 2011; 89:1817-829. [ Links ]
Jacela JY, Frobose HL, DeRouchey JM, Tokach MD, Dritz SS, Goodband RD, Nelssen JL. Amino acid digestibility and energy concentration of high-protein corn dried distillers grains and high-protein sorghum dried distillers grains with solubles for swine. J Anim Sci 2010; 88:3617-623. [ Links ]
Jansman AJM, Smink W, van Leeuwen P, Rademacher M. Evaluation through literature data of the amount and amino acid composition of basal endogenous crude protein at the terminal ileum of pigs. Anim Feed Sci Technol 2002; 98:49-60. [ Links ]
Ji Y, Zuo L, Wang F, Li D, Lai C. Nutritional value of 15 corn gluten meals for growing pigs: chemical composition, energy content and amino acid digestibility. Arch Anim Nutr 2012; 66:283-302. [ Links ]
Kim BG, Petersen GI, Hinson RB, Allee GL, Stein HH. Amino acid digestibility and energy concentration in a novel source of high-protein distillers dried grains and their effects on growth performance of pigs. J Anim Sci 2009; 87:4013-021. [ Links ]
Leterme P, Théwis A. Effect of pig bodyweight on ileal amino acid endogenous losses after ingestion of a protein-free diet enriched in pea inner fibre isolates. Reprod Nutr Dev 2004; 44:407-17. [ Links ]
Li SF, Niu YB, Liu JS, Lu L, Zhang LY, Ran CY, Feng MS, Du B, Deng JL, Luo XG. Energy, amino acid, and phosphorus digestibility of phytase transgenic corn for growing pigs. J Anim Sci 2013; 91:298-308. [ Links ]
Moter V, Stein HH. Effect of feed intake on endogenous losses and amino acid and energy digestibility by growing pigs. J Anim Sci 2004; 82:3518-525. [ Links ]
Moughan PJ, Schuttert G. Composition of nitrogen-containing fractions in digesta from the distal ileum of pigs fed a proteinfree diet. J Nutr 1991; 121:1570-574. [ Links ]
NRC. Nutrient Requirements of Swine. 11th rev. ed. Washington, DC: Natl Acad Press; 2012. [ Links ]
Otto ER, Yokoyama M, Ku PK, Ames NK, Trottier NL. Nitrogen balance and ileal amino acid digestibility in growing pigs fed diets reduced in protein concentration. J Anim Sci 2003; 81:1743-753. [ Links ]
Pahm AA, Pedersen C, Hoehler D, Stein HH. Factors affecting the variability in ileal amino acid digestibility in corn distillers dried grains with solubles fed to growing pigs. J Anim Sci 2008; 86:2180-189. [ Links ]
Pedersen C, Boersma MG, Stein HH. Energy and nutrient digestibility in NutriDense corn and other cereal grains fed to growing pigs. J Anim Sci 2007; 85:2473-483. [ Links ]
Petersen GI, Smiricky-Tjardes MR, Stein HH. Apparent and standardized ileal digestibility of amino acids in gelatin-based diets by growing pigs. Anim Feed Sci Technol 2005; 119:107-15. [ Links ]
Ren P, Zhu Z, Dong B, Zang J, Gong L. Determination of energy and amino acid digestibility in growing pigs fed corn distillers' dried grains with solubles containing different lipid levels. Arch Anim Nutr 2011; 65:303-19. [ Links ]
Reyna L, Figueroa JL, Martínez RD, Cervantes M. Apparent and standardised ileal digestibilities and growth performance of finishing pigs fed diets formulated with new corn hybrids. J Appl Anim Res 2011; 39:225-29. [ Links ]
Sauvant D, Perez J-M, Tran G. Tables of Composition and Nutritional Value of Feed Materials. 2nd rev.ed. The Netherlands & INRA, Paris, France: Wageningen Academic Publishers; 2004. [ Links ]
Stein HH, Benzoni G, Bohlke RA, Peters DN. Assessment of the feeding value of South Dakota-grown field peas (Pisum sativum L.) for growing pigs. J Anim Sci 2004; 82:2568-578. [ Links ]
Stein HH, Gibson ML, Pedersen C, Boersma MG. Amino acid and energy digestibility in ten samples of distillers dried grain with solubles fed to growing pigs. J Anim Sci 2006; 84:853-60. [ Links ]
Stein HH, Pedersen C, Wirt AR, Bohlke RA. Additivity of values for apparent and standardized ileal digestibility of amino acids in mixed diets fed to growing pigs. J Anim Sci 2005; 83:2387-395. [ Links ]
Stein HH, Sève B, Fuller MF, Moughan PJ, de Lange CFM. Invited review: Amino acid bioavailability and digestibility in pig feed ingredients: Terminology and application. J Anim Sci 2007; 85:172-80. [ Links ]
Stein HH, Trottier NL, Bellaver C, Easter RA. The effect of feeding level and physiological status on total flow and amino acid composition of endogenous protein at the distal ileum in swine. J Anim Sci 1999; 77:1180-187. [ Links ]
Urriola PE, Hoehler D, Pedersen C, Stein HH, Shurson GC. Amino acid digestibility of distillers dried grains with solubles, produced from sorghum, a sorghum-corn blend, and corn fed to growing pigs. J Anim Sci 2009; 87:2574-580. [ Links ]
Viljoen J, Fick JC, Coetzee SE, Hayes JP, Siebrits FK. Apparent and true amino acid digestibilities of feedstuffs in pigs employing the total ileal content (TIC) technique and the mobile nylon bag technique (MNBT). Livest Sci 1998; 53:205-15. [ Links ]
Warnants N, Van Oeckel MJ, De Paepe M. Response of growing pigs to different levels of ileal standardised digestible lysine using diets balanced in threonine, methionine and tryptophan. Livest Prod Sci 2003; 82:201-09. [ Links ]
Widmer MR, McGinnis LM, Stein HH. Energy, phosphorus, and amino acid digestibility of high-protein distillers dried grains and corn germ fed to growing pigs. J Anim Sci 2007; 85:2994-3003. [ Links ]
Yin YL, Li TJ, Huang RL, Liu ZQ, Kong XF, Chu WY, Tan BE, Deng D, Kang P, Yin FG. Evaluating standardized ileal digestibility of amino acids in growing pigs. Anim Feed Sci Technol 2008; 140:385-401. [ Links ]
Zhai H, Adeola O. Apparent and standardized ileal digestibilities of amino acids for pigs fed corn- and soybean meal-based diets at varying crude protein levels. J Anim Sci 2011; 89:3626–633. [ Links ]
Zhang Y, Li D, Fan S, Piao X, Wang J, Han IK. Effects of casein and protein-free diets on endogenous amino acid losses in pigs. Asian-Aust J Anim Sci 2002; 15:1634-638. [ Links ]
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