Seventy piglets with no access to creep feed were weaned at 28 d of age and fed on one of four diets based on either skimmed-milk powder (SMP), soya-bean-protein concentrate (SPC), soya-bean meal (SBM) or fish meal (FM). At 0, 3, 6 and 10 d after weaning, piglets were killed and the pancreas and digesta from stomach and small intestine were collected, freeze-dried and analysed for dry matter (DM), N, and trypsin (EC 3.4.21.4) and chymotrypsin (EC 3.4.21.1) activities. Small-intestinal tissue samples were taken to examine gut wall morphology. Results indicated that dietary protein source affected postweaning feed intake, pancreatic weight, gastric pH and gastric protein breakdown, and pancreatic and jejunal trypsin and chymotrypsin activities. Post-weaning feed intake appeared to be an important factor in digestive development of newly-weaned piglets. Pancreas: Dietary protein: PigletIn pigs, digestive disorders are frequently encountered in the early post-weaning period. The protein digestive capacity of newborn piglets is adapted to the digestion of milk proteins. Proteins of plant origin are digested to a lesser extent than milk proteins resulting in poor performance when fed to newly-weaned piglets (Wilson & Leibholz, 1981 a, c). It has been hypothesized (Jones, 1986) that this may be due to insufficient development of the pancreatic enzyme system, since many authors report a decline in enzyme activities following weaning (Lindemann et QI. 1986; Owsley et QI. 1986). However, the often impaired feed intake of newly-weaned piglets may also play a role in this respect.The present experiment was designed to study the development of pancreatic enzymes of newly-weaned piglets in relation to dietary protein source and post-weaning feed intake. M A T E R I A L S A N D M E T H O D SSeventy piglets with no access to creep feed during the suckling period were weaned at 28 d of age. Ten piglets were anaesthetized immediately after weaning (day 0), weighed and exsanguinated from the jugular veins and artery. During exsanguination the gastrointestinal tract was divided into four segments: stomach, duodenum (first 2 m from pylorus), ileum (last 2 m of the small intestine) and jejunum (remaining part of the small intestine). Digesta were collected quantitatively from the stomach and small intestine segments. Usually, death of the piglets occurred after the tissue and digesta samples had been collected. In

Seventy pigs were weaned at 25 d of age and fed diets based on either skim-milk powder (SMP) or soybean protein concentrate (SOY). At 0, 3, 6, and 10 d after weaning, pigs were anesthetized, their pancreases were removed, and digesta were collected from different sections of the digestive tract. The ratio between trichloroacetic acid (TCA)-precipitable protein and total (crude) protein (pp:cp) in gastric digesta was higher with SOY feed than with SMP feed. In the jejunum, no difference was found; hence, the degree of protein breakdown in jejunal chyme did not differ between protein sources. Trypsin activities in jejunal chyme and in pancreatic tissue increased (P < .01) after weaning. Chymotrypsin activity in pancreatic tissue tended to decrease after weaning and did not reach "weaning levels" for at least 10 d. Pancreatic trypsin developed more rapidly than chymotrypsin after weaning. Chymotrypsin activities in jejunal digesta were higher (P < .05) for the pigs fed SMP than for those fed SOY. Protease activities in the jejunum at d 6 after weaning were clearly affected (P < .05) by feed intake after weaning. The ratio between trypsin and chymotrypsin activity in jejunal chyme was higher (P < .05) for SOY-fed pigs than for SMP-fed pigs. It was concluded that the stomach plays an important role in the digestion of milk protein and that the development of pancreatic proteases after weaning (synthesis, secretion, breakdown) depends on feed intake and on dietary protein source.

Zusammenfassung Der Pankreas spielt eine zentrale Rolle bei den Verdauungsprozessen. Der Pankreassaft kontrolliert den pH‐Wert im Duodenum (Pufferkapazität) und enthält Verdauungsenzyme, deren Aktivitäten sich an die Nahrungszusammensetzung anpassen. Die altersabhängigen Unterschiede des Pankreassaftes sind vor allem im Hinblick auf die Entwicklung von Rationen für frühabgesetzte Ferkel von Bedeutung. In der vorliegenden Arbeit werden Angaben über die Enzymaktivitäten im Pankreassaft in Abhängigkeit von Alter und Ration gemacht und Adaptationsmöglichkeiten diskutiert.

Fourteen piglets, initially weighing 8 kg, were each fitted with a Post Valve T-Caecum (PVTC) cannula and two catheters, one in a jugular vein and one in a carotid artery. Piglets received one of four experimental diets containing either skimmilk powder (SMP), soyabean meal (SBM), soya protein isolate (SI) or fish meal (FM) as the sole protein source; the crude protein content in the diets was from about 17 to 18.4% of DM. The diets were given in equal amounts at 12 h intervals. ,5 N-L-leucine was intravenously infused continuously at a rate of about 40 mg l5 N-L-leucine per kg body weight per day. Apparent and true faecal nitrogen (N) digestibilities were 94.0 and 97.3, 84.0 and 93.5, 90.8, and 98.1 and 89.1 and 96.4% for the SMP, the SBM, the SI and the FM diets, respectively. Daily endogenous faecal N losses were 315, 963, 715 and 697 mg and daily endogenous ileal N losses were 786, 1422, 1970 and 1558 mg for diets SMP, SBM, SI and FM, respectively. Apparent ileal nitrogen (N) digestibilities were 84.4, 76.5, 78.4 and 73.0%, true ileal N digestibilities were 92.7, 90.6, 98.4 and 89.3% for diets SMP, SBM, SI and FM, respectively. It was concluded that true N digestibilities were high for all four protein sources, both at the ileal and at the faecal level. Differences in apparent N digestibility were mainly caused by differences in endogenous N secretion.

Zusammenfassung Die Lagerung von Pankreassaft vom Schwein: Einflüsse auf Enzymaktivitäten Insgesamt wurden 80 Pankreasproben von Schweinen bei unterschiedlichen Temperaturen (4°C, –20°C, –80°C) für eine unterschiedliche Zeitspanne (0 bis 21 d) gelagert. Untersucht wurden die Enzymaktivitäten von Trypsin, Chymotrypsin und Lipase. Aus den Ergebnissen geht hervor, daß die Enzymaktivitäten von der Lagerungstemperatur abhängig sind. Die Aktivitäten von Trypsin, Chymotrypsin und Lipase zeigen nach einer Woche bei der Lagerung bei 4°C unterschiedliche Ergebnisse im Vergleich zu frisch gewonnenen Proben. Bei den gefrorenen Proben blieben die Enzymaktivitäten im Vergleich zu frischen Proben über 21 d konstant.