Use of markers to determine the ileal digestibility of amino acids for swine

Abstract

Many markers can be used in digestibility assays for swine, but needs to be evaluated before its use. An assay was carried out with the objective of measuring the coefficients of ileal apparent (CIAD) and standardized digestibility (CISD) of amino acids in meat and bone meal for swine using different markers. Eight crossbred barrows were equipped with T-cannulas in the distal ileum. Four animals received a free protein diet and another four received a diet containing meat and bone meal as the only protein source in the diet. The treatments consisted in evaluating the chromic oxide, acid-insoluble ash naturally occurring in the diet, cellulose and lignin as markers to determine the apparent and standardized digestibility of the amino acids contained in the meat and bone meal. All data were submitted to analysis of variance and means were compared using the Tukey test, with a significance of 5%. The CIAD, obtained using chromic oxide as external marker, were lower (P<0.05) than those obtained when acid insoluble ash, lignin and cellulose were used as markers, observing differences for all the amino acids evaluated. Similarly, the CISD from all the studied amino acids were lower (P<0.05) when the chromic oxide was used for determining the indigestibility factor. It is concluded that chromic oxide used as a external marker, to determine the coefficients of apparent and standardized ileal digestibility of the amino acids of the meat and bone meal, is most appropriate than the acid insoluble ash naturally occurring in diets, lignin and cellulose.Index terms: Acid-insoluble ash, cellulose, chromic oxide, lignin, simple T-cannula. RESUMOMuitos indicadores podem ser utilizados em ensaios de digestibilidade para suínos, mas precisam ser avaliados antes de serem utilizados. O experimento foi realizado com o objetivo de determinar os coeficientes de digestibilidade ileal aparentes (CDIA) e estandardizados (CDIE) dos aminoácidos da farinha de carne e ossos, para suínos, utilizando diferentes indicadores. Oito suínos, machos castrados, foram submetidos à cirurgia para aimplantação de cânulas T simples, no íleo distal. Quatro animais receberam uma dieta isenta de proteína e outros quatro uma dieta contendo farinha de carne e ossos como única fonte protéica na dieta. Os tratamentos consistiram em avaliar o óxido crómico, cinza insolúvel em ácido naturalmente contido na dieta, celulose e lignina como indicadores para determinar os CDIA e CDIE dos aminoácidos da farinha de carne e ossos. Os dados foram submetidos a análise de variância e as médias foram comparadas pelo teste de Tukey, ao nível de 5% de significância. Os CDIA, obtidos usando o óxido crômico como indicador externo, foram menores (P<0,05) em relação aos obtidos utilizando cinza insolúvel em ácido, lignina e celulose como indicadores, observando-se diferenças para todos os aminoácidos avaliados. O CDIE de todos os aminoácidos estudados foram menores (P<0,05) quando o óxido crômico foi utilizado para a determinação do fator de indigestibilidade. Conclui-se que...

Chromic oxide and acid‐insoluble ash as markers in digestibility studies with growing pigs and sows

“…In the present study, we found no differences in digestibility values estimated by different digestibility markers neither in terms of the total tract digestibility of DM, OM, N, Ca and P nor in terms of ileal digestibility of AA and N. Also other studies reported no or only little differences in ileal digestibility (Van Leeuwen et al, 1996) or total tract digestibility of nutrients (Laerke et al, 2012) when Cr 2 O 3 and AIA were compared. Contrary to these results, other studies reported greater ileal digestibility coefficients of AA when Cr 2 O 3 was used in comparison with AIA (Fan and Sauer, 2002;Pozza et al, 2013;Favero et al, 2014). The content of fibre in the diet may significantly influence ileal digestibility of AA and N determined by Cr 2 O 3 and AIA (Fan and Sauer, 2002).…”

“…In the studies of Fan and Sauer (), Pozza et al. () and Favero et al. (), Cr 2 O 3 was analysed according to Fenton and Fenton (), after ashing at 450 °C followed by acid digestion and measured at 440 nm.…”

“…The digestibility studies dealing with the comparison of Cr 2 O 3 and AIA as digestibility markers were carried out in chickens (Scott and Boldaji, 1998), pigs (Laerke et al, 2012;Pozza et al, 2013) and also in humans (Rowan et al, 1991). These studies involved monitoring of total tract digestibility, ileal digestibility or both, including studies estimating an ileal endogenous flow of AA and CP (Fan and Sauer, 2002).…”

“…In the study of Van Leeuwen et al (1996), the content of Cr 2 O 3 was analysed colorimetrically after ashing at 525°C and following oxidation, Cr 2 O 3 was consequently measured at 372 nm. In the studies of Fan and Sauer (2002), Pozza et al (2013) and Favero et al (2014), Cr 2 O 3 was analysed according to Fenton and Fenton (1979), after ashing at 450°C followed by acid digestion and measured at 440 nm. Similarly, Yin et al (2001) reported that different analytical methods used for the determination of Cr 2 O 3 may be the factor which effect final results when compared to the digestibility determined using Cr 2 O 3 and AIA.…”

“…Several digestibility studies objected to total tract digestibility (Van Leeuwen et al, 1996) or ileal digestibility (Fan and Sauer, 2002;Laerke et al, 2012;Pozza et al, 2013) of different nutrients were performed to compare Cr 2 O 3 and AIA as digestibility markers. But the results were controversial.…”