During the past two decades endogenous gut N losses (ENL) at the distal ileum in the growing pig have received considerable attention in swine nutrition research. Estimates of ENL are important for...

Significance of endogenous gut nitrogen losses in the nutrition of growing pigs: A review

1. Six pigs, initially of 35 kg mean live weight, were each fitted with a re-entrant cannula. This was formed on either side of a short pouch of duodenum into which the pancreatic duct opened and which contained a simple cannula linked to the centre of the re-entrant cannula.2. Each pig received two diets: diet A was based on wheat starch, sucrose and casein, while diet B was based on barley and soya-bean meal. The diets were given in equal amounts at 12 h intervals.3. Digesta and pancreatic juice were collected continuously during three 12 h periods for each pig on each diet.4. Mean duodenal output: dietary intake values for diets A and B respectively were: digesta 1·80, 2·86; dry matter 1·05, 1·03; nitrogen 1·05, 1·06; trichloroacetic acid (TCA)-soluble N 7·69, 9·10; glucose 0·97, 0·89. For diet A the proportion of TCA-soluble N in total N rose from 13 to 50% during 12 h, while it was approximately 50% throughout 12 h for diet B.5. Mean total pepsin (EC 3.4.23.1) activities (units/24 h) were 760449 (diet A) and 1466571 (diet B).6. Salivary and gastric secretions were calculated to be approximately 4 and 8 kg/24 h for diets A and B respectively.7. Mean flows in pancreatic juice (g/24 h) for diets A and B respectively were: juice 1204, 2182; protein 10·94, 12·10; N 1·98, 2·14; ash 9·46, 17·31; sodium 3·88, 6·91; potassium 0·23, 0·54: calcium 0·031, 0·046; phosphorus 0·024, 0·026.8. Mean total enzyme activities (units × 10−3/24 h) for diets A and B respectively were: trypsin (EC 3.4.21.4) 138, 114; chymotrypsin (EC 3.4.21.1) 84, 84; carboxypeptidase A (EC 3.4.2.1) 5, 4; carboxypeptidase B (EC 3.4.2.2) 15, 17; amylase (EC 3.2.1.1) 1061, 981.9. It was calculated that the minimum amount of endogenous N from saliva and gastric secretion was 0·3–0·6 g in 24 h. This assumes no absorption of N occurred anterior to the duodenal cannula.

Studies on gastric digestion of protein and carbohydrate, gastric secretion and exocrine pancreatic secretion in the growing pig.

Six ileal-cannulated pigs that averaged 100 kg BW and 16 adult cecectomized cockerels that averaged 2.35 kg BW were used to determine apparent and true digestibilities of amino acids (AA) in a complete crystalline AA mixture and in casein. A protein-free (PF) diet was included as a treatment to estimate endogenous AA losses. Fasted cockerels were compared to cockerels fed PF diets for calculation of true digestibility of AA in cockerels. For the AA diet, true digestibility of indispensable AA in the pig ranged from a low of 97.2% for leucine to a high of 100.5% for arginine (Arg). True digestibility of indispensable AA in casein ranged from a low of 93.5% for isoleucine (Ile) to a high of 99.9% for Arg. Correcting for endogenous losses increased digestibilities of lysine (Lys) and threonine (Thr) in pigs fed the AA diet by 2.4 and 7.1%, respectively, and increased Lys and Thr digestibility in pigs fed the casein diet by 1.8 and 6.1%, respectively. Feeding a PF diet to chickens to correct for endogenous losses resulted in higher true digestibility values for all AA with the exception of tryptophan, methionine, and Arg than those obtained using fasted animals. True digestibilities of Thr were 88.3 and 86.6% for AA and casein diets, respectively, using fasted controls but were 97.5 and 94.5% when the PF control was used. Proline digestibility was increased (P < .05) substantially in both pigs and cockerels when the PF control was used to correct for endogenous AA losses. Regardless of species, Ile in casein had a lower true digestibility value than any other indispensable AA. The results of this study indicated that true digestibilities of AA in a mixture of crystalline AA and in casein are essentially 100% in both pigs and cockerels.

Apparent and true amino acid digestibility of a crystalline amino acid mixture and of casein: comparison of values obtained with ileal-cannulated pigs and cecectomized cockerels.

An experiment was conducted to estimate by simple linear regression the levels of endogenous amino acids in digesta collected from the distal ileum in pigs. Six barrows, average initial BW 35 kg, were fitted with a simple T-cannula at the distal ileum and fed six diets according to a 6 x 6 Latin square design. Six cornstarch-based diets containing six levels of CP from soybean meal (4, 8, 12, 16, 20, and 24% CP, respectively) were formulated. Chromic oxide (.4%) was included as the digestibility marker. Each experimental period consisted of 8 d. Ileal digesta were collected, at 2-h intervals, for a total of 24 h during d 7 and 8. There were linear relationships (P < .001) between dietary contents of apparent ileal digestible and total amino acids, irrespective of the ranges in graded dietary levels of amino acids. Determined with the regression technique, the endogenous levels of the indispensable amino acids (grams/kilogram of DMI) were as follows: arginine, .64; histidine, .23; isoleucine, .46; leucine, .69; lysine, .47; methionine, .13; phenylalanine, .31; threonine, .69; and valine, .54. Differences in the ranges of graded dietary levels of amino acids resulted in large differences in the estimated amounts of endogenous amino acids in ileal digesta. Furthermore, it seems that the levels of endogenous amino acids, as grams/kilogram of DMI, were constant at different dietary levels of amino acids, whereas the contributions of endogenous amino acids, as percentages of their dietary contents, decreased curvilinearly with increasing dietary contents. Therefore, apparent ileal digestibilities of amino acids were quadratically related to their dietary contents until plateau digestibilities were reached, whereas the true ileal digestibilities of amino acids were independent of their respective dietary contents. Furthermore, true ileal amino acid digestibilities should be determined from their corresponding plateau apparent ileal digestibilities. In conclusion, the levels of endogenous amino acids in ileal digesta can be determined reliably from the linear relationships between dietary contents of apparent ileal digestible and total amino acids. An important methodological consideration in the determination of endogenous amino acids by regression analysis is to design an appropriate range of graded dietary levels of amino acids.

Estimation by regression analysis of endogenous amino acid levels in digesta collected from the distal ileum of pigs

Summary

Large quantities of specific egg antibodies can be produced with little effort by immunization of laying hens. Several antibody containing egg preparations were subjected to a tenacity test against digestive activity taking piglets with artificial jejunum fistulas as a model. Even with high doses of orally administered yolk lyophilisate no antibody activity could be found in the distal jejunum. The additional feeding of egg white, however, showed a significant protective effect on the yolks antibodies during the digestive act. No difference between egg white of immunized hens and egg white of unimmunized hens could be detected. Buffering the acidic gastric environment with sodium bicarbonate increased the antibody activity in the intestine by an average of 40 %. Eggs administered in hot (70 °C) beef stock had higher antibody titers than eggs that were boiled for 4 minutes. Tenacity in antibodies fed in pellets was significantly lower than in powdered feed.



Zusammenfassung

Huhnerei-Antikorper fur Prophylaxe und Therapie infektioser Darmerkrankungen III. In vivo-Tenazitatstest bei Ferkeln mit kunstlicher Jejunalfistel



Durch Immunisierung von Legehennen lassen sich kostengunstig grose Mengen von spezifischen Eiantikorpern produzieren. Am Modell des Ferkels mit Dunndarmfistel wurden verschiedene antikorperhaltige Eizubereitungen auf ihre Tenazitat gegenuber Verdauungsvorgangen hin uberpruft. Selbst bei hohen Dosen von oral verabreichtem Dotterlyophilisat konnte im distalen Jejunum keine Antikorperaktivitat festgestellt werden. Zufutterung von Eiklar dagegen zeigte eine erhebliche Schutz-wirkung auf die Dotterantikorper wahrend des Verdauungsvorganges, unabhangig davon, ob das Eiklar von immunisierten oder nicht immunisierten Huhnern stammte. Eine Pufferung des sauren Magenmilieus durch Natriumbicarbonat bewirkte eine durchschnittliche 40%ige Erhohung der Antikorperaktivitat im Darminhalt. Eier in 70 °C heiser Bouillon verabreicht wiesen hohere Antikorpertiter auf als 4 Minuten gekochte Eier. Bei Antikorpern, die in Pellets verarbeitet waren, war die Tenazitat gegenuber Antikorpern in losem Futter deutlich vermindert.

Chicken egg antibodies for prophylaxis and therapy of infectious intestinal diseases. II. In vitro studies on gastric and enteric digestion of egg yolk antibodies specific against pathogenic Escherichia coli strains.

1. Pancreatic juice was collected from six pigs of 48 kg initial weight fitted with a collection catheter in the pancreatic duct and a return catheter in the duodenum. 2. Measurements of flow and composition of the juice were made during 24 h periods after adaptation to isonitrogenous diets based on barley, wheatings and fish meal (diet BWF) or starch, sucrose, casein, maize oil and cellulose (diet SSC), given in a change-over design. Measurements were also made during the periods of adaptation to a change from one diet to the other. 3. Mean flow-rates for pigs adapted to diets showed a highly significant four-fold difference between diets; values were 4962 ml/d for diet BWF and 1273 ml/d for diet SSC. The hourly volumes of juice were very variable and showed no clear response to feeding and no consistent diurnal pattern for either diet. 4. There were no significant differences between diets in the specific activities of the proteases. Average values were (units/mg protein) trypsin (EC 3.4.21.4) 29.6, chymotrypsin (EC 3.4.21.1) 7.7, carboxypeptidase A diet BWF than with diet SSC. The specific activities and total outputs of alpha-amylase (EC 3.2.1.1) and lipase (EC 3.1.1.3) were significantly higher for diet BWF than for diet SSC; specific activities for the two diets respectively were: (units/mg protein) alpha-amylase 95-6 and 42.3, lipase 59.0 and 14.5. 5. The higher daily volume of juice with diet BWF was associated with significantly (but only slightly) higher levels of both sodium and potassium, compared with diet SSC. 6. The results are discussed in relation to previous studies on digestion at this Institute, in which pigs with intestinal cannulas were given the same diets.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/C3F3AB44969FC278A143650986654619/S0007114582000191a.pdf/div-class-title-the-influence-of-diet-on-the-exocrine-pancreatic-secretion-of-growing-pigs-div.pdf

I. E. Sambrook

Papers

The influence of diet on the exocrine pancreatic secretion of growing pigs.