A new in vitro method for the estimation of digestibility using the intestinal fluid of the pig

Abstract

I . A new in vitro method using the intestinal fluid of the pig for predicting the digestibility of diets was proposed.2. A 0.5 g sample of pig diet was placed in a IOO ml Erlenmeyer flask, 20 mg pepsin (EC 3 . 4 . 4 . I ) in 10 rnlo.075 M-hydrochloric acid was added, and the mixture was incubated for 4 h at 37". Then, after neutralization with 0.2 M-sodium hydroxide, 10 ml of intestinal fluid was added and incubated for an additional 4 h at 37". This fluid was obtained from a pig fitted with a simple cannula in the upper jejunum.After the two-stage incubations, the contents of the flask was centrifuged for 10 min at 1250 g and the residue transferred to preweighed filter paper for dry matter (DM) and crude protein (nitrogen x 6 2 5 ; CP) determinations. The in vitro DM and CP digestibility was calculated on the basis of the original DM and CP content of the diet respectively.3. The intestinal fluid could be stored at -zoo for 60 d without losing its activity on DM and CP digestion.4. A high correlation was found between this in vitro method and the standard in vivo procedures, for seven diets commonly used for growing or adult pigs, when diets were ground to pass through a I mm screen for the in vitro experiment, but there was an obvious dissimilarity between the two methods, especially where Y and X are in vivo and in vitro digestibility respectively.5 . This method is rapid and reproducible and particularly suited for the evaluation of a large number of samples. Since this method assesses only stomach and small intestinal digestion, it therefore may require further modification when used for diets which include large amounts of crude fibre. Also, depending on the needs of the investigator, the addition of a correction factor for endogenous faecal nitrogen loss may be required.

Digestibilities of nitrogen and amino acids in soya-bean, sunflower, meat and rapeseed meals measured with pigs and poultry

“…These workers used a more dilute solution of pepsin (0-002% (weight/volume)) than that used in this trial (0-2% weight/volume), so their test was likely to have been of greater sensitivity (Johnston and Coon, 1979b). Other workers have extended the pepsin test to include an incubation in pancreatin (Furuya, Sakamoto and Takahashi, 1979;Clunies and Leeson, 1984) and found good correlation of the results with nitrogen digestibility measured in vivo. The relative success of these in vitro methods as cheap, yet sound indices of nitrogen digestibility highlights the necessity for further study of the relationships between the digestibilities of nitrogen and those of the key essential amino acids, with the eventual objective of being able to predict amino acid digestibility from nitrogen digestibility measured in vitro.…”

Critical Evaluation of in Vitro Methods for Estimating Digestibility in Simple-Stomach Animals

“…However, several multi-enzyme methods have been investigated in detail. Graham et al (1989) The results with the pepsin-jejunal fluid method were found to be closely correlated to faecal digestibility of protein and dry matter in pigs (Furuya et al 1979) and in poultry (Sakamoto et al 1980). Dierick et al (1985) compared results obtained with the pepsin-jejunal method with results from two other two-step in vitro methods, both including pepsin in the first step, but one using pancreatin and the other pronase in the second step.…”

“…A two-step incubation with pepsin digestion for 4 h followed by a further 4-h digestion with pig jejunal fluid was developed by Furuya et al (1979). The method was used for measuring in vitro digestibility of protein and dry matter.…”

In vitro fermentation of different ratios of alfalfa and starch or inulin incubated with an equine faecal inoculum

“…The SFD treatment was adapted from the method of Furuya et al (1979), whereby of 20 ml of pepsin HCl (0.075 mol l -1 HCl; 2 mg pepsin ml Substrate combinations were fermented in vitro with an equine faecal inoculum using the in vitro gas production (GP) technique of Theodorou et al (1994). Methods employed for the GP technique were as described by Theodorou et al (1994); each bottle contained 85ml…”