Prececal digestibility of various sources of starch in minipigs with or without experimentally induced exocrine pancreatic insufficiency.

Low prececal digestibility of starch leads to a higher starch flux into the hindgut, causing a forced microbial fermentation, energy losses, and meteorism. For exocrine pancreatic insufficiency (EPI), lack of pancreatic amylase can be compensated mostly by hindgut fermentation of starch. Even in pigs with complete loss of pancreatic secretion, starch digestibility over the entire tract is reaching levels of controls. To optimize diets for human patients with EPI, the proportion of starch that is digested by the ileum is important. Minipigs were fitted with an ileocecal reentrant fistula (n = 8) to determine prececal digestibility of starch. In 5 minipigs the pancreatic duct was ligated (PL) to induce EPI; 3 minipigs served as controls (Con). Various starch sources were tested in a 1-d screening test; therefore, disappearance rate (DR) instead of digestibility was used. Test meals consisted of 169 g DM of a basal diet plus 67.5 g DM of the starch (without thermal treatment; purified; starch content of 89 to 94.5%) and Cr(2)O(3). The test meal contained (% of DM) starch, 67; crude fat, 1.69; CP, 15; crude fiber, 2.0; and Cr(2)O(3), 0.25. In PL, prececal DR of starch was lower than in Con (P < 0.05) for all starch sources. In Con, prececal DR of starch was almost complete (>90%) but was lower (P < 0.05) for potato (Solanum tuberosum) starch (75.4%). In PL, prececal DR of starch was higher (P < 0.05) for wheat (Triticum aestivum) starch (61.2%) than corn (Zea mays) starch (43.0%) and rice (Oryza sativa) starch (29.2%) and intermediate for potato and field pea (Pisum sativum) starch. For patients with EPI, wheat starch seems favorable due to the higher prececal digestibility whereas raw corn and rice starch should be avoided.

The growing pancreatic duct ligated pig as a model for exocrine pancreatic insufficiency in children: investigations to achieve sufficient vitamin A and vitamin E supply.

Human patients suffering from exocrine pancreatic insufficiency (EPI) are susceptible to deficiencies in fat-soluble vitamins. In children with cystic fibrosis, EPI is common and aspects of sufficient vitamin supply are of special interest. The aim of this study was to determine the best application form to maintain vitamin A and E levels in the physiological range in growing pigs with EPI (induced by pancreatic duct ligation) as a model for children. The pancreatic duct was ligated (PL) in twelve 8-wk-old pigs; 4 sham-operated pigs served as controls (Con). Pigs (n = 16) were individually housed and fed a diet containing 13,393 IU vitamin A and 122 mg vitamin E/kg DM. The PL pigs (n = 12) were divided into 3 groups (n = 4) 2 wk after surgery: PL-0, without extra vitamin supply; PL+ORAL, 90,000 IU vitamin A and 600 mg vitamin E/kg of DM plus emulsifier E 484 added to the diet; and PL+IM, intramuscular injection of vitamin A (5,250 IU) and vitamin E [aqueous; 3.15 mg/(kg BW · wk)] plus 700 mg vitamin E (oily)/(animal · wk). All PL pigs were supplemented with the pancrelipase Creon (19.8 g = 1,048,727 IU lipase/kg feed) beginning 2 wk after ligation of the pancreatic duct. Pigs were euthanized at 16 wk of age. Tocopherol levels (mg/kg DM) in liver were reduced (P ≤ 0.005) in PL-0 and PL+IM (6.91 and 8.61, respectively) whereas PL+ORAL did not differ from Con (27.4 and 25.8, respectively; P ≥ 0.77). Compared to control pigs (241 ± 14.1 mg vitamin A/kg DM of liver), the concentration of vitamin A (mg/kg DM) in liver was lower (P < 0.003) in PL-0 (136 ± 18.5) but higher (P < 0.003) in PL+ORAL (375 ± 50.0). In the group PL+IM a high individual variation was observed (288 ± 142 mg vitamin A/kg DM of liver). Extra dietary supply of high doses of vitamin A and E with an efficient emulsifier was adequate to maintain vitamin A and E in liver tissue within reference values. The present data underline the need for extra supplementation of vitamin A and E in juvenile patients with EPI and indicate that oral application is suitable.

Effect of diet grinding and pelleting fed either dry or liquid feed on dry matter and pH in the stomach of pigs and the development of gastric ulcers.

The physical form of diets has a marked impact on the development of gastric ulcers in pigs. Earlier studies showed effects of fine grinding and pelleting on the integrity of gastric mucosa as well as on local intragastric milieu. This study was conducted to evaluate the effects of dry or liquid feeding on intragastric milieu (DM and pH) in pigs. The 23 piglets were housed individually and fed with test diets and water ad lib for 6 wk. Both experimental diets [coarsely ground diet fed as mash (CM) vs. finely ground pelleted diet (FP)] were identical in ingredients (39.5% wheat, 34% barley, 20% soybean meal) and chemical composition and were either offered dry or in liquid (25% DM) form. At the end of the trial the animals were slaughtered; the stomach was removed and samples were taken from different localizations. Feeding diets dry or liquid had no effect on the pH (P > 0.05). The diet noticeably affected the gastric content. The FP diets resulted in a more liquid chyme (P < 0.05), and the intragastric pH did not differ between regions. Feeding CM caused marked effects of localization regarding pH (highest values: pars nonglandularis; lowest values: fundus). None of the pigs fed CM showed signs of gastric ulcers, but the score was markedly higher (P < 0.05) when pigs were fed FP. Therefore the predominant factor for development of gastric ulcers seems to be the structure (particle size) of the diet.

[Analysis of feedstuff for pigs, sent in from veterinary practices for quality control]. / Untersuchung von Futtermitteln für Schweine, eingesandt aus der tierärztlichen Praxis zur Qualitätskontrolle.

OBJECTIVE: Nutritional disorders and a reduced performance are common reasons to send in feedstuffs for quality control. The following review illustrates the main nutritional-related problems on pig farms and presents possible causal relationships between feed/feeding and health disorders. MATERIAL AND METHODS: The analysis results of feedstuff and drinking water samples that were sent to the institute for animal nutrition between 2000 and 2009 were evaluated retrospectively. RESULTS: Certain trends were revealed. Whereas previously fertility disorders gave rise to analysis of food samples, in recent years the grinding intensity of mixed feeds (potential relationship to gastric ulcers) has become of more interest. Mixed feed in meal form (n=143) showed a usual particle size structure, whereas pelleted and crumbled diets exhibited undesirable, higher proportions of fine particles. A contamination with pests was only found in a few feed samples (0.9% of analysed feedstuffs in 2007). With only a few exceptions the feedstuffs were of a satisfactory hygienic quality. With respect to the chemical composition of the mixed feeds, differences between analysed and labelled levels were detected in terms of crude fibre (63.0% of 138 analysed feed samples). More than 50% of the feedstuffs (n=64) showed aberrations in the botanical composition. Samples of drinking water were checked to an increasing extent (n=120 in 2009) probably due to the fact that drinking water is defined by law as a feedstuff and evaluation criteria exist. Elevated levels of iron and aerobe bacteria (in 50% and 30.8% of samples, respectively) were among the most common findings. CONCLUSION AND CLINICAL RELEVANCE: The spectrum of analyses has been expanded in recent years. In many cases a relationship could be found between clinical symptoms and alterations within the feed or the drinking water.

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.

Impacts of forest fragmentation on the mating system and genetic diversity of white spruce (Picea glauca) at the landscape level.

We studied the mating system of white spruce (Picea glauca) in a landscape fragmented by agriculture in northern Ontario, Canada. We sampled 23 stands that ranged in size from 1 to >500 trees isolated by 250-3000 m from the nearest other stand. Six polymorphic allozyme loci from four enzyme systems were used to genotype approximately 10 000 embryos from 104 families. We detected no allele frequency heterogeneity in the pollen pool among stands or families (Phi(FT)=-0.025). Overall, estimates of outcrossing were high (t(m)=94% and mean t(s)=91%) but significantly different from unity. Bi-parental inbreeding (t(m)-t(s)=3.2%) was low but significantly different from zero. Allozyme-based outcrossing estimates did not differ significantly among three stand-size classes (SSCs): small (<10 trees), medium (10-100 trees) and large (> or =100 trees). The number of effective pollen donors was high in all SSCs, but was significantly lower in small stands (N(ep)=62.5) than in medium-sized and large stands (both N(ep)=143). The primary selfing rate was significantly higher in medium stands than in large stands. We found no significant difference in genetic diversity measures in the filial (seed) population among SSCs. Overall, these results indicate that white spruce stands in this fragmented landscape are resistant to genetic diversity losses, primarily through high pollen-mediated gene-flow and early selection against inbred embryos. We discuss the importance of using seed data, in conjunction with genetic data, to evaluate the impacts of fragmentation on natural populations.

Old-growth red spruce forests as reservoirs of genetic diversity and reproductive fitness.

Old-growth forests are assumed to be potential reservoirs of genetic diversity for the dominant tree species, yet there is little empirical evidence for this assumption. Our aim was to characterize the relationship of stand traits, such as age, height and stem diameter, with the genetic and reproductive status of old-growth and older second-growth stands of red spruce (Picea rubens Sarg.) in eastern Canada. We found strong relationships between height growth (a fitness trait) and measures of genetic diversity based on allozyme analyses in red spruce. The negative relationship between height and the proportion of rare alleles suggests that high proportions of these rare alleles may be deleterious to growth performance. Latent genetic potential, however, showed a significant and positive relationship with height. Stand age was not correlated to height, but was correlated to seedling progeny height. In late-successional species such as red spruce, age and size (e.g., height and stem diameter) relationships may be strongly influenced by local stand disturbance dynamics that determine availability of light, growing space, moisture and nutrients. In larger and older stands, age appeared to provide a good surrogate measure or indicator for genetic diversity and progeny height growth. However, in smaller and more isolated populations, these age and fitness relationships may be strongly influenced by the effects of inbreeding and genetic drift. Therefore, older populations or old-growth forests may represent superior seed sources, but only if they are also of sufficient size and structure (e.g., stem density and spatial family structure) to avoid the effects of inbreeding and genetic drift. Thus, larger and older forests appear to have an important evolutionary role as reservoirs of both genetic diversity and reproductive fitness. Given the rapid environmental changes anticipated (as a result of climate change, increasing population isolation through fragmentation, or following the introduction of exotic pests and diseases) these older populations of trees may have a valuable function in maintaining the adaptive potential of tree species.

Isolation, characterization, inheritance and linkage of microsatellite DNA markers in white spruce (Picea glauca) and their usefulness in other spruce species.

Microsatellite DNA/simple-sequence-repeat (SSR) loci were identified, isolated and characterized in white spruce (Picea glauca) by screening both a non-enriched partial genomic library and a partial genomic library enriched for (AG/TC)n-containing clones. Inheritance and linkage of polymorphic SSR loci were determined in F1 progeny of four controlled crosses. We also assessed the compatibility and usefulness of the P. glauca microsatellite DNA markers in five other Picea species. Twenty-four microsatellites were identified by sequencing 32 clones selected from screens of 5,400 clones from the two libraries. The (AG/TC)n microsatellites were the most abundant in the non-enriched library. Eight microsatellite DNA loci were of the single-copy type, and six of these were polymorphic. A total of 87 alleles were detected at the six polymorphic SSR loci in 32 P. glauca individuals drawn from several populations. The number of alleles found at these six SSR loci ranged from 2 to 22, with an average of 14.5 alleles per locus, and the observed heterozygosity ranged from 0.48 to 0.91, with a mean of 0.66 per locus. Parents of the controlled crosses were polymorphic for five of the six polymorphic SSR loci. Microsatellite DNA variants at each of these five SSR loci followed a single-locus, codominant, Mendelian inheritance pattern. Joint two-locus segregation tests indicated complete linkage between PGL13 and PGL14, and no linkage between any of the remaining SSR loci. Each of the 32 P. glauca individuals examined had unique single or two-locus genotypes. With the exception of non-amplification of PGL12 in P. sitchensis, P. mariana, and P. abies and the monomorphic nature of PGL7 in P. mariana, primer pairs for all six polymorphic SSR loci successfully amplified specific fragments from genomic DNA and resolved polymorphic microsatellites of comparable sizes in P. engelmanni, P. sitchensis, P. mariana, P. rubens, and P. abies. The closely related species P. mariana and P. rubens, and P. glauca and P. sitchensiss could be distinguished by the PGL12 SSR marker. The microsatellite DNA markers developed and reported here could be used for assisting various genetics, breeding, biotechnology, tree forensics, genome mapping, conservation, restoration, and sustainable forest management programs in spruce species.