W. B. Souffrant

Ernährungsphysiologische Untersuchungen an Schweinen zur Beurteilung von modifizierten Proteinen

Modified proteins were tested in absorption investigations with eight pigs with ileocaecal re-entrant cannulae. The apparent digestibility up to the end of the small intestines showed considerable differences between the feed proteins (77-93%). The same differences could be observed with regard to the apparent absorption of amino acids. Concerning the true N-digestibility resp. the true absorption of the amino acids in the above mentioned section of the intestinal tract there were hardly any differences between the proteins given. The results show that there is a relation between the amount of endogenous N in the chyme at the end of the small intestines and the protein consumed. The amount of endogenous N in the chyme in the small intestines influence N-excretion in urine and thus the intermediary utilisation of feed protein. From the point of view of nutrition physiology it follows that the spun vicia-faba protein/casein (1 : 1) fibres (C) approximate best the value of casein (A). While the treatment of this mixed protein with dyaldehyde starch had a negligible effect on the ascertained parameters only, the treatment of the same protein with aluminium chloride diminished its value more. The isolated vicia-faba (B) was the poorest of the modified proteins tested.: Modified proteins were tested in absorption investigations with eight pigs with ileocaecal re-entrant cannulae. The apparent digestibility up to the end of the small intestines showed considerable differences between the feed proteins (77-93%). The same differences could be observed with regard to the apparent absorption of amino acids. Concerning the true N-digestibility resp. the true absorption of the amino acids in the above mentioned section of the intestinal tract there were hardly any differences between the proteins given. The results show that there is a relation between the amount of endogenous N in the chyme at the end of the small intestines and the protein consumed. The amount of endogenous N in the chyme in the small intestines influence N-excretion in urine and thus the intermediary utilisation of feed protein. From the point of view of nutrition physiology it follows that the spun vicia-faba protein/casein (1 : 1) fibres (C) approximate best the value of casein (A). While the treatment of this mixed protein with dyaldehyde starch had a negligible effect on the ascertained parameters only, the treatment of the same protein with aluminium chloride diminished its value more. The isolated vicia-faba (B) was the poorest of the modified proteins tested.

Untersuchungen zur Bestimmung der endogenen N-Sekretion im Dünndarm bei Schweinen

The method of isotope dilution for the determination of endogenous N-secretion was used with three pigs of a live weight of between 15 and 27 kg, which were provided with simple cannulae at the end of the small intestines. The test animals received a single dose of a semi-synthetic ration with 15N-labelled dried curds as sole source of protein. The passage rate to the ileum ascertained with the help of 51Cr2O3 was 70% in 24 hours. During the test period of 24 hours the endogeneous N-amount in the ileum chyme was 1.11 g resp. 56.6 mg/kg live weight. Of that, 60% were allowed to be absorbed in the chyme at the end of the small intestine.

[N-metabolism as modelled by metabolism of 15N-labelled wheat in rat experiment].

Male albino rats of a weight of 90 g received a test ration with 15N-labelled wheat as protein source over a period of 1 to 8 days. The 15N-excess in urine, feces, some organs, the remaining carcass and in the blood was determined in dependence on time. On the basis of two different pool models the N-metabolism values could be calculated. Protein synthesis and disintegration rates calculated by means of the N- and 15N-balances of the pool in the steady state of the pool labelling amounted to 252.9 mg N per day resp 203.0 mg N per day. The calculation based on the time-dependent curve of the daily 15N-excretion in urine resulted in corresponding synthesis and disintegration rates of 197.0 mg N per day and 134.6 mg N per day. Labelling curve and results are discussed.

Untersuchungen zur Dünndarmresorption von proteingebundenem N und synthetischem Methionin bei Schweinen

The absorption and absorbility of the protein-linked N was investigated with 3 pigs in the live weight range between 15 and 27 kg, which had been provided with simple cannulae at the end of the ileum and with portal vene catheters. After receiving a semi-synthetic ration with 15N-labelled curds as sole protein source, supplemented with 0,3% 35S-DL-methionine, the course of absorption could be observed both for 15N and 35S with the help of the chyme samples. Considering the endogenous 15N-quota in the chyme in the small intestines, it was possible to acquire data concerning the apparent and true absorption resp. absorbility of the feed-N. It could be ascertained that the supplemented synthetic amino acid is better absorbed than the protein-linked amino acids. So the absorption of 35S amounted to 91,2% of the intake whereas only 84,2% of the labelled N was observed.

Untersuchungen zur exokrinen Pankreassekretion beim Schwein nach Verfütterung von Sojaextraktionsschrot

Exogenous N-secretion of the pancreas was investigated with growing pigs with fistulae in the pancreas. For this purpose the two protein sources toasted and untoasted soybean oilmeal were used. After the feeding of untoasted soybean oilmeal a significant increase of the secretion volume and of protein outpour could be observed in contrast to toasted soybean oilmeal within 24 h. The heat-labile soybean trypsin inhibitor also caused an activity increase of the pancreatic enzymes.