Effect of partial dehulling of two- and six-row barley varieties on precaecal digestibility of amino acids in pigs

Abstract

Five barrows (German Landrace; initial BW 58 kg, final BW 80 kg) fitted with an ileo-rectal anastomosis were used to determine the effect of partial dehulling and addition of barley hulls of two- and six-row barley varieties on the precaecal digestibility (pD) of CP and amino acids. The following diets were provided according to a standardized diet formulation and tested in seven consecutive periods (repeated group-period design): two-row barley (TRB) + casein (C), dehulled TRB + C, TRB + C + 10% hulls, six-row barley (SRB) + C, dehulled SRB + C, SRB + C + 1% hulls, and wheat starch + C. The diets were supplied at daily rates of 79-86 g DMI x kg BW(-0.75) in barley containing diets and at 49 g DMI x kg BW(-0.75) in the casein diet. The digestibility of amino acids in barley varieties was determined by the difference method (casein as basal diet) using quantitative digesta collection. In both varieties of barley the pD of CP and amino acids did not differ. The pD of CP was unchanged in regard to the treatments in both barley varieties. Due to dehulling in TRB the pD was improved significantly for most indispensable amino acids and in SRB for Met and Cys. Addition of 10% hulls to TRB led to equivalent pD of Arg, His, Leu, Tyr, and Trp compared to TRB, but the pD of Lys, Phe, Thr and Val was significantly decreased below the levels of TRB. Addition of even 1% hulls to SRB impaired the pD of Lys below the level in SRB. In conclusion, addition of barley hulls to pig diets impairs amino acids absorption in the small intestine. The pD values, measured under standardized experimental conditions (without a correction using basal endogenous amino acids), are similar to the values of true digestibility published by NRC (1998).

Evaluation through literature data on standardized ileal digestibility and basal ileal endogenous loss of amino acids associated with barley in pigs

“…The SID of CP and most AA estimated by regression analysis were in the range of SID values in barley reported in other studies (Hennig et al, 2006;Ige et al, 2010), and corresponded (95% confidence intervals) to SID values reported by NRC (2012) and AFZ et al (2000). (Eklund, 2006).…”

“…Thus, nutrient digestibility of barley in pigs can be substantially reduced (O'Connell et al, 2005). Moreover, less interaction between diet and digestive enzymes may result in increased specific ileal endogenous losses of CP and AA, as digesta viscosity inhibits sufficient interaction between (Chesson, 1993; Nyachoti et al, 2000;Jansman et al, 2002).The SID of CP and most AA estimated by regression analysis were in the range of SID values in barley reported in other studies (Hennig et al, 2006;Ige et al, 2010), and corresponded (95% confidence intervals) to SID values reported by NRC (2012) and AFZ et al (2000). (Eklund, 2006).…”

“…The world production of barley amounts to over 134 million tons annually (FAOSTAT, 2011), therefore, and due to its low purchase cost, barley is the most important crop in diets for livestock after wheat and maize (Leterme et al, 2000;Hennig et al, 2006;FAOSTAT, 2011). The protein content of cereal grains including barley is considerably lower than that of protein supplements such as soya bean meal, but due to their high dietary inclusion level, cereal grains can supply up to 60% of pigs' requirements for CP and amino acids (AA) (Myrie et al, 2008).…”

Partial dehulling of barley effect the concentrations of both gross and ileal digestible amino acids in pigs

“…In order to decrease the crude fibre (CF) in barley seeds the husk can be mechanically removed without knowledge how the nutritive value for pigs will be affected. Complete information about methodological aspects in digestibility determination of 18 proteinbound AA in the two barley varieties was recently presented (Hennig et al, 2006). The objective of the current contribution is to briefly describe how dehulling affect both the concentrations of gross AA and of ileal digestible AA.…”

Prediction of standardized ileal digestibility and essential amino acid content of ingredients in swine: A meta-analysis

“…1 and 2). (Sauer et al, 1977;Cousins et al, 1981;Sauer et al, 1981;Taverner et al, 1981;Walter et al, 1981;Adeola et al, 1986;Lin et al, 1987;Batterham et al, 1990;Herkelman et al, 1990;Haydon and Hobbs, 1991;Noblet et al, 1993;Adeola and Orban, 1995;Van Barneveld et al, 1998;Buraczewska et al, 1999;Reverter et al, 1999;Stein et al, 1999;O'Quinn et al, 2000;Cho et al, 2001;Fan and Sauer, 2002;Moeser et al, 2002;Yin et al, 2002;Fan and Sauer, 2003;Song et al, 2003;Mariscal-Landín et al, 2004;Snow et al, 2004;Kaufmann et al, 2005;Hennig et al, 2006;Muley et al, 2007;Opapeju et al, 2007;Pedersen et al, 2007;Lahaye et al, 2008;Nyachoti et al, 2010). c Ns: number of studies; Nt: number of ingredients in the model.…”