A.J.M. Jansman

Evaluation through literature data of the amount and amino acid composition of basal endogenous crude protein at the terminal ileum of pigs

The paper summarizes and evaluates data on estimates for the amount and amino acid (AA) composition of basal endogenous crude protein (CP) at the terminal ileum of pigs derived from 33 ileal digestibility studies with pigs (30-100 kg BW). Different methods and approaches are used to obtain these estimates: (A) the N-free diet method (16 studies), (B) calculations based on ileal digestibility values of diets with highly digestible protein sources (casein or wheat gluten) (11 studies), (C) the regression method (3 studies), (D) the enzymatic hydrolyzed casein (EHC) method (2 studies) and (E) the N-free diet method with intravenous infusion of AAs (1 study). The mean values for the flow of basal endogenous ileal CP (6.25 × N) for the five respective methods were 10.5, 12.6, 12.0, 17.1 and 12.7 g/kg dry matter (DM) intake. The overall mean value using all observations was 11.8 g/kg DM intake. The mean AA composition of basal endogenous protein (g/16 g N) was estimated as 3.2 for isoleucine, 4.2 for leucine, 3.4 for lysine, 1.0 for methionine, 1.8 for cystine, 2.9 for phenylalanine, 2.6 for tyrosine, 5.1 for threonine, 1.2 for tryptophan, 4.5 for valine, 3.4 for arginine and 1.6 for histidine. The flow of basal endogenous ileal CP and AAs can be considered as an inevitable loss for the pig. Data on the flow of basal endogenous protein and AAs can be used to calculate true or standardized ileal digestibility values or corrected apparent ileal digestibility values of feed ingredients for pigs. The use of more accurate and additive ileal digestibility values of AAs in feed ingredients improves diet formulation for pigs, in which AA supply via the diet is matched with AA requirements.

The influence of α-galactosidase supplementation on the ileal digestibility of lupin seed carbohydrates and dietary protein in young pigs

Eighteen cannulated piglets were used in two experiments (six in Experiment 1 and 12 in Experiment 2) to determine the effect of supplementation of the diet with microbial α-galactosidase on the ileal digestibility of the raffinose family oligosaccharides and other nutrients of lupin-based diets. Three semi-purified diets with the seed meal of yellow lupin (Lupinus luteus L.) cvs Juno and Amulet or narrow-leafed lupin (Lupinus angustifolius) cv Saturn were offered to pigs with or without the enzyme supplementation (5 g kg-1). About 80% of the α-galactosides were digested up to the end of the small intestine of pigs (Experiment 1) fed on the diet with cv Juno without the enzyme supplementation. When α-galactosidase was added to the diet, digestibility of α-galactosides significantly increased to 97%. Results of Experiment 2 showed that the ileal digestibility of sucrose (92.9%), stachyose (71.9%) and verbascose (83.4%) of narrow-leafed lupin cv Saturn was higher than the corresponding values for yellow lupin cv Amulet (86.3, 60.1 and 77.8%). The ileal digestibility of raffinose was 52.2% for cv Saturn and 40.7% for cv Amulet. The ileal digestibility of total non-starch polysaccharides (NSP) was 11% for cv Amulet and 14% for cv Saturn. α-Galactosidase supplementation significantly improved the digestibility of the raffinose series oligosaccharides and positively affected the ileal digestibility of most amino acids (P < 0.05).

Dietary effects of faba-bean (Vicia faba L.) tannins on the morphology and function of the small-intestinal mucosa of weaned pigs

The objective of the present study was to evaluate effects of condensed tannins in faba beans (Vicia faba L.) on morphological and functional variables of the small-intestinal mucosa of piglets. In an experiment with young piglets (8-17 kg body weight), fed on either a control diet or a diet containing 200 g/kg of low- or high-tannin faba bean hulls (with < 0.10 and 3.3% catechin equivalents of condensed tannins respectively), morphological and functional characteristics of the jejunal mucosa were determined. Results of the study showed that the morphological variables of the mucosa of the three groups of piglets were similar. Also, no changes due to dietary tannins were observed in sucrase (EC3.2.1.48)-isomaltase (EC 3.2.1.10) activity in homogenates of mucosa plus submucosa. However, aminopeptidase (EC 3.4.11.2) activity in these homogenates in the proximal part of the small intestine of the animals of the group fed on the high-tannin diet was significantly lower than that in the animals fed on the control diet or the diet with low-tannin hulls (P < 0.05).

Apparent protein digestibility and recovery of endogenous nitrogen at the terminal ileum of pigs fed diets containing various soyabean products, peas or rapeseed hulls

Effects of the use of three different soyabean products (soya concentrate and two different soyabean meals), peas or rapeseed hulls in the diet on the apparent ileal digestibility of CP (N x 6.25) and recovery of ileal endogenous nitrogen (N) in weanling pigs were investigated. Ileal endogenous N was measured using the 15N-isotope dilution method. Thirteen castrated male pigs (BW of 12-23 kg) were fed maize starch-based diets containing either soya concentrate (SC), purified rapeseed hulls (pRH) and SC (SRH diet), soyabean meal (SBM), a mixture of toasted and untoasted soyabean meal (mSBM) or peas. The apparent ileal digestibility (AID) of dry matter (DM) for the SC, SRH, SBM, mSBM and pea diets was 82.1, 74.3, 83.3, 80.0 and 74,9% (P < 0.05), respectively. The AID of CP for these diets was 82.4, 67.6, 81.6, 68.0 and 76.9% (P < 0.05), respectively. Similar differences in the AD for amino acids (AA) in the diets were found. The AID for CP and for the sum of AA in the pRH, as calculated by the difference between the SC and SRH diet, were 26 and 41%, respectively. For the SC, SRH, SBM, mSBM and pea diet, ileal recovery (g/kg of DM intake) for endogenous N were 2.79, 3.46, 2.73, 4.89 and 3.29 (P < 0.05), respectively, and for dietary N 1.16, 4.11, 1.64, 4.15 and 2.53 (P < 0.05), respectively. For the SC, SBM and mSBM diets, differences in AID of CP and AA were associated with differences in both the ileal recovery of endogenous N and the recovery of undigested dietary N. Differences in trypsin inhibitor activity (TIA) of the soya products were likely associated with these observations. It was also concluded that fibre (Neutral Detergent Fibre; NDF) in pea could be at least in part responsible for the relatively low AD of CP and AA and the high recovery of ileal endogenous N in the pea diet. The low AD of CP and AA of pRH was likely related to the association of protein to the fibre matrix in the fibre-rich rapeseed hulls.

Nitrogen balance of pigs as affected by feedstuffs causing different endogenous nitrogen flow at the terminal ileum

Abstract The effect of ileal endogenous nitrogen (N) flow on N balance in pigs was investigated. In two experiments pigs (BW 12 to 24 kg) were fed a maize starch-based diet containing either wheat gluten (WG), peas, or rapeseed meal (RSM). In Experiment 1, apparent ileal N digestibility was measured with 12 ileal cannulated pigs. Amount of ileal endogenous N was measured in six of these pigs with the 15N-isotope dilution technique. Apparent and true ileal N digestibilities were 91.4 and 98.6 for the WG diet, 80.5 and 95.6 for the pea diet, 67.2 and 80.1% for the RSM diet, respectively. Significant differences (P

Mathematical analysis of apparent ileal digestibility values of amino acids in feedstuffs for pigs.

Abstract The aim of the present study was to investigate within and among feedstuffs the variation of apparent ileal digestibility of amino acids. The interest was in developing models which estimate the apparent amino acid digestibility of feedstuffs. These equations can be useful for practical feed formulation, possibly in combination with in vitro techniques. For mathematical analysis, literature data on apparent ileal digestibility of protein and individual amino acids in feedstuffs were collected in a database (290 batches of 40 different feedstuffs). From this database the apparent ileal digestibility for each amino acid was described in an equation which contained two variables; the apparent ileal digestibility value of protein of the different feedstuffs and the reciprocal of the relative contribution of amino acids to the protein in the feedstuff. The former variable reflects the apparent amino acid digestibility values. The latter variable relates to the deviation in amino acid composition of endogenous protein and feed protein. In the analysis each individual observation was included. Individual feedstuffs or different experimental techniques were not studied separately. The explained part of the variance (R 2 ) of most of the amino acids ranged from 0.6 to 0.8. The models, which describe the variation in apparent digestibility among amino acids, were also used to estimate the amino acid profile of endogenous protein.