NBT-PABA test to assess efficiency and kinetics of substituted proteolytic enzyme action in pancreatic duct ligated minipigs.

The NBT-PABA test is an established method for diagnosis of pancreatic exocrine insufficiency. In the present study the NBT-PABA test was used to test and compare the efficacy of two multienzyme preparations (product A and B) differing in galenic preparation in minipigs in which pancreatic exocrine insufficiency (PEI) was induced by pancreatic duct ligation. Without enzyme substitution no distinct increase in PABA was found in blood after oral administration of NBT-PABA. Administration of both enzyme preparations led to a clear dose dependent rise in PABA-concentrations in blood. Interestingly, the two preparations showed different time curves of serum PABA concentration, indicating differences in the kinetic of proteolytic enzyme action. It is concluded that the NBT-PABA test can be a very useful test for indirectly evaluating proteolytic enzyme efficacy in vivo, and also gives information about the kinetics of enzyme action, not only the end-result of enzyme action (like digestibility trials which were used traditionally). A single test is performed in a few hours and there is no need for fistulated animals.

The influence of an increased cobalt supply to dairy cows on the vitamin B status of their calves.

In the experiment the influence of an elevated oral cobalt supply (Co content in the ration 0.27 mg Co/kg DM; supplement of 0.14 mg Co/kg DM as CoSO(4)) to pregnant dairy cows on the vitamin B(12) concentration in milk, colostrum and vitamin B(12) status of their calves was tested in comparison with unsupplemented controls (0.13 mg Co/kg DM). While there was no significant difference in vitamin B(12) concentration in the at 70th day of lactation (start of the experiment; 3.77 +/- 1.41 vs. 3.66 +/- 1.03 ng/ml) and 290th day of lactation (almost drying off; 4.75 +/- 3.05 vs. 4.44 +/- 0.96 ng/ml), cobalamin concentration in the milk colostrum showed a tendency towards a higher cobalt content in the ration of the supplemented cows in comparison with the controls (21.0 +/- 8.4 vs. 16.7 +/- 11.9 ng/ml). Differences in the vitamin B(12) concentration in the serum of the newborn calves before and after ingestion of colostrum were not detected. From these results it can be concluded that cobalt content of 0.13 mg Co/kg DM in the ration based on wilted grass silage seems to be sufficient for pregnant dairy cows.

Effects of Fusarium toxin-contaminated wheat grain on nutrient turnover, microbial protein synthesis and metabolism of deoxynivalenol and zearalenone in the rumen of dairy cows.

The aim of the present study was to examine the effects of feeding Fusarium toxin-contaminated wheat to dairy cows on nutrient utilization in the rumen and on duodenal flow of deoxynivalenol (DON), zearalenone (ZON) and their metabolites. Six dairy cows fitted with a large rumen cannula and a simple T-shaped cannula at the proximal duodenum was used in two experiments. The experiments included a control period in which the uncontaminated control wheat was fed and a period in which the control wheat was replaced by the Fusarium toxin-contaminated wheat (8.05 and 7.15 mg DON/kg and 0.26 and 0.1 mg ZON/kg in Expts 1 and 2 respectively). The wheat portion of the daily ration amounted to 50% on a dry matter (DM) basis and rations were completed with hay or grass silage. Five of the six cows were non-lactating and the total daily DM-intake ranged between 4 and 12 kg. The pH-values and the concentration of volatile fatty acids in ruminal fluid were not significantly influenced by feeding the contaminated wheat. In contrast, the postprandial ammonia concentration was consistently higher when the mycotoxin-contaminated wheat was fed. Moreover, the flow of microbial protein and utilizable protein at the duodenum were reduced at the same time. The concentrations of DON and ZON and of their metabolites in freeze-dried duodenal digesta were either not detectable or negligible during the control periods whereas distinct concentrations were measured during the periods where the contaminated wheat was fed. DON was nearly completely metabolized to de-epoxy-DON and the flow at the duodenum ranged between 4% and 28% of DON-intake. The ZON metabolites alpha-zearalenol (ZOL) and beta-ZOL were recovered at the duodenum beside the parent toxin ZON. Their recovery as a percentage of ZON-intake ranged between 43% and 132%. In conclusion, feeding of Fusarium toxin-contaminated wheat altered the ruminal protein utilization. The question of whether this effect was a result of the mycotoxin being present in the rumen or of Fusarium growth-related structural (cell wall) changes of the wheat grain needs to be clarified. The low recovery of DON at the duodenum would indicate either a nearly complete degradation of the molecule in the rumen or an absorption by the mucosa of the rumen, whereas the higher ZON recovery would suggest a lower degradation of the parent toxin in the rumen and/or recovery of some bile-originating entero-hepatic cycling ZON/metabolites.

Investigations on prophylactic effects of coarse feed structure and/or potassium diformate on the microflora in the digestive tract of weaned piglets experimentally infected with Salmonella Derby.

The purpose of this study was to examine potential prophylactic effects of a coarse feed structure and/or potassium diformate (KDF as feed additive) addition to diets on the microflora of the digestive tract in reared piglets experimentally infected with Salmonella Derby. The results show that coarse grinding as well as KDF addition are able to influence positively the intestinal flora and are capable to reduce Salmonella excretion of infected piglets. Coarse grinding of main ingredients (e.g. cereals) led to an increased number of lactobacilli as well as to higher counts of Gram-positive coccoid bacteria in the colon chyme, while KDF resulted in a tendency towards lower counts of Escherichia coli within the digestive tract. Moreover, a combination of both treatments influenced the composition of the gastrointestinal flora quite positively. Furthermore, the combination of these dietetic measures resulted in a reduced Salmonella excretion rate, shorter Salmonella shedding period and a reduced translocation of Salmonella within the infected piglets. The positive effects of combining both treatments led to a significantly reduced spreading of Salmonella within the group of pigs, which might be used to diminish Salmonella prevalence in pig production.

Digestibility rates of major and trace elements in pancreatic duct-ligated pigs.

Ligation of pancreatic duct in pigs leads to a severe maldigestion of calcium and magnesium. Substitution of missing enzymes results in a 'normalization' of the digestibility rates of these elements. In comparison to controls the pre-caecal phosphorus digestibility decreased, but the total digestibility rates increased, after ligation of the pancreatic duct. Furthermore, the total amount of absorbed phosphorus was significantly higher in pancreatic duct ligated pigs. Further studies have to be carried out to investigate, whether phosphorus in exocrine pancreatic insufficiency is excreted with urine, as in this study the observed Ca:P-ratio in blood was in a physiological range. Without a forced renal excretion of phosphorus, consequences and risks (e.g. secondary hyperparathyroidism) of the regulation have to be considered. Regarding the elements sodium, potassium and chloride, an increased faecal excretion could be observed in pancreatic duct ligated pigs. As a substitution with enzyme products led to digestibility rates similar to those in controls, no losses of electrolytes have to be feared. Even though pancreatic juice seems to have influences on the digestibility of investigated trace elements (copper, zinc, iron and manganese), it did not lead to severe imbalances in the corresponding mineral metabolism.

Experiments to optimize enzyme substitution therapy in pancreatic duct-ligated pigs.

Ligation of the pancreatic duct in pigs leads to severe maldigestion and malabsorption of crude nutrients. Supplementation with 24 capsules of Creon (Solvay Pharmaceuticals GmbH, Hannover, Germany) per meal led to an increased digestibility of crude nutrients. With regard to optimization of the treatment of EPI no essential improvements can be achieved by adding omeprazol or lecithin to the diet. In pancreatic duct-ligated pigs the isolated addition of omeprazol led to an increase of the pre-caecal digestibility of crude fat and organic matter. With additional enzyme substitution, the application of omeprazol did not result in an improved fat digestibility. Isolated addition of lecithin to the diet resulted in a reduced total digestibility of crude fat. Offering the diet twice a day and using a higher frequency of enzyme applications (four or six instead of only two applications) had no effects on the digestibilty of crude fat or organic matter. According to the observations in pancreatic duct-ligated pigs, the addition of missing enzymes to the diet led to the best treatment results in EPI. Administration of omeprazol or a higher feeding frequency as well as the application of enzymes in small proportion of the whole meal or dosages given consecutively over the day showed no advantages. Furthermore, the present study suggests that the addition of lecithin cannot be recommended in EPI, when given diets with butter as the predominant fat source as in human dietetics.

Beet-vinasse (condensed molasses solubles) as an ingredient in diets for cattle and pigs - nutritive value and limitations.

Sugar beet vinasse, originating as the condensed molasses residue from yeast production, was fed to bulls and pigs to determine the feed value. It contained, per kg dry matter (DM content 66.8%), 293 g crude protein, 305 g N-free extract (therefrom 34.4 g total sugar), and 395 g crude ash. The experiment was carried out with three fattening bulls (German Holstein) and four adult pigs (Gottingen Minipig). In bulls, two balance trials lasting 20 days each (10 days adaptation; 10 days collection) were conducted in which subsequently a basal ration without and with vinasse (14% in DM) was fed. In pigs, the experiment consisted of three 12-day balance trials with the final 5 days as collection period. In the first trial, pigs received a basal diet without vinasse and in the following, a mixed diet with 16 and 43% vinasse (in DM) respectively. Digestibilities of components in vinasse in bulls were: organic matter 73.5%, crude protein 72.6%, and N-free extract 52.3%. In bulls, no influence on faeces quality could be detected while feeding 14% vinasse in DM. While feeding 16% vinasse in DM to pigs, the digestibility of organic matter amounted to 72.3% (crude protein 71.8%; NfE 74.6%). Feeding higher amounts of vinasse (43% in DM) in the diet of pigs, digestibilities were reduced (organic matter: 61.6%), which might be a result of a reduced retention time of the chyme as a result of an osmotically driven diarrhoea because of unexpectedly high sulphate (136 g/kg DM) content in the vinasse. It is concluded that because of organic matter digestibility >70% for cattle and pigs, the use of vinasse in these species in small proportions is reasonable.