In vitro degradation of phytate and lower inositol phosphates in soaked diets and feedstuffs

A series of in vitro experiments simulating liquid feeding were performed to evaluate the effect of microbial phytase addition, heat-treatment and soaking time on degradation of phytate and lower inositol phosphates when soaking compound wheat/soybean meal diets or the single feedstuffs wheat or soybean meal. The effect of phytase addition on phytate degradation was greatest in soybean meal, almost intermediate for wheat/soybean meal diets and not detectable in wheat, which might be due to a better accessibility to phytate in soybean meal compared with wheat. Heat-treatment seemed to enhance the accessibility between phytase and phytate, whereby phytate degradation was stimulated. Additionally, it was shown that wheat phytase is able to stimulate degradation of phytate in soybean meal. Independent of treatment, the amount of IP₅–IP₂ was extremely small in relation to phytate in both wheat and soybean meal, indicating that when one phosphate group is removed from the phytate complex, degradation of IP₅–IP₂ is completed. Consequently, it is anticipated that liquid feeding might result in a higher digestibility of plant P compared with dry feeding of pigs.     

The degradation of quintozene,pentachlorobenzene, hexachlorobenzene and pentachloroaniline in soil

The disappearance of quintozene (I) and its technical impurities and metabolites pentachlorobenzene (III), hexachlorobenzene (IV) and pentachloroaniline (V) from soil, was studied in laboratory experiments under controlled conditions during a period of about 600 days. The very high persistence found, was confirmed by the analysis of 22 samples collected from fields used for potato growing and treated regularly during the foregoing 11 years with commercial formulations of quintozene. In the laboratory experiments, III, V and methylthiopentachlorobenzene (VI) were found to be degradation products from the quintozene.     

The influence of the pH of feed on the acid-base balance of mink.

The acid-base balance in small carnivores (mink, Mustela vison) was examined during 6 feeding periods, when the same animals were given different feeds during a prolonged time. The feeds consisted of normal farm feed to which different amounts of sulphuric acid-preserved feed and feed silaged with organic acids were added (Tables I--II). When the pH of the feed was decreased to below 5.5, the acid-base balance of the animals was changed and metabolic acidosis occurred (Tables III--V, Fig. 1). On neutralization of the acid-preserved feed a normal acid-base balance could be maintained. However, the growth of the animals was reduced after prolonged feeding with silage as they lost weight during the following periods (Table vii).     

Prevalence and distribution of gastro-intestinal helminths and haemoparasites in young scavenging chickens in upper eastern region of Ghana, West Africa

We conducted a cross-sectional study to determine the prevalence and species of gastro-intestinal helminths and haemoparasites in 100 chickens kept under extensive management systems in Ghana, West Africa. All the examined chickens (100%) were infected with gastro-intestinal helminths; a total of 18 species were detected. The species and their prevalences were: Acuaria hamulosa (25%), Allodapa suctoria (20%), Ascaridia galli (24%), Capillaria spp. (60%), Choanotaenia infundibulum (13%), Gongylonema ingluvicola (62%), Heterakis gallinarum (31%), H. isolonche (16%), Hymenolepis spp. (66%), Raillietina cesticillus (12%), R. echinobothrida (81%), R. tetragona (59%), Strongyloides avium (2%), Subulura strongylina (10%), Tetrameres fissispina (58%), Trichostronygylus tenuis (2%), and finally one unidentified acanthocephalan (1%) and one unidentified trematode (1%). Thirty-five per cent of the chickens were infected with the haemoparasites Aegyptinella pullorum and Plasmodium juxtanucleare (prevalences 9% and 27%, respectively). Association between chicken sex and prevalences was not significant. An over-dispersed distribution was seen for most of the helminth species.     

A hereditary disposition for bovine peripheral nerve sheath tumors in Danish Holstein cattle

Background

Peripheral nerve sheath tumors (PNSTs) are frequently found in Danish cattle at slaughter. Bovine PNSTs share several gross and histopathological characteristics with the PNSTs in humans with heritable neurofibromatosis syndromes. The aim of the present study was to investigate a possible hereditary disposition to PNSTs in dairy cattle by statistical analysis performed on data from 567 cattle with PNSTs. Furthermore, a preliminary genome-wide association study (GWAS) was performed on DNA isolated from 28 affected and 28 non-affected Holstein cows to identify loci in the bovine genome involved in the development of PNSTs.

Results

PNSTs were significantly more common in the Danish Holstein breed than in other breeds with 0.49% of Danish Holsteins slaughtered during an eight-year-period having PNSTs. PNSTs also occurred significantly more frequently in the offspring of some specific Holstein sires. Examination of three generation pedigrees showed that these sires were genetically related through a widely used US Holstein sire. The PNSTs included in GWAS were histologically classified as neurofibroma-schwannoma (43%), schwannoma (36%) and neurofibroma (21%) and derived from Holstein cows with multiple PNSTs. A single SNP on chromosome 27 reached genome-wide significance.

Conclusions

Gross and histological characteristics of bovine PNSTs are comparable to PNSTs in humans (schwannomatosis). Danish Holsteins are genetically disposed to develop PNSTs but the examined materials are insufficient to allow determination of the mode of inheritance.     

Oligonucleotide fingerprinting of resynthesized Brassica napus

Brassica napus plants, artificially synthesized through somatic hybridization of B. oleracea and B. campestris protoplasts, were analyzed by oligonucleotide fingerprinting. While the fingerprint patterns of the different hybrid plants looked very much alike, they did not simply represent a combination of the parental patterns. Instead, the absence of parental bands as well as the presence of new bands suggest that elimination and/or rearrangements occurred during or after the fusion of the two genomes. The fingerprints of individual F1 progeny plants of selfed hybrids did not detect major changes. Thus, once formed, the artificially resynthesized amphidiploid B. napus genome appears to be stable. Taken together, our experiments demonstrate the usefulness of oligonucleotide fingerprinting for the characterization of artificial hybrids in the genus Brassica.     

Genetic transformation of Brassica

Tissue culture regeneration of plants from Brassica species can be achieved from various explant types. Their performance, however, varies with the genotype and age of the explant and is sensitive to medium supplements and Agrobacterium cocultivation. Most Brassica transformations were carried out using Agrobacterium and it was established that nopaline and agropine strains of A. tumefaciens and A. rhizogenes, respectively, are the most efficient. Application of virulence gene induction is ambiguous. Binary vectors are mostly applied in spite of indications that cointegrate vectors are more efficient. Cotransformation is successful with two different bacteria or with one bacterium carrying both plasmids, however, it has proved problematic to integrate the two transgenes into separate loci. Transformations with wild type rol genes develop hairy roots, from which transgenic plants can be regenerated. Vectorless transformation is feasible with microprojectile bombardment of microspore derived embryos being the most promising. Antibiotic markers providing resistance to kanamycin, hygromycin, and spectinomycin are applicable as selectable markers, while chloramphenicol is not suitable. Among herbicides, phosphinotricin gives good results while chlorsulfuron is unsuitable for in vitro selection. Major therapeutic antibiotics being successfully applied are carbenicillin, cefotaxime, amoxycillin, and ticarcillin. Standard methods for evaluating transgenic plants also have been applied to Brassica species. Some breeding objectives obtained through genetic transformation are presented.     

The presence of inositol phosphates in gastric pig digesta is affected by time after feeding a nonfermented or fermented liquid wheat- and barley-based diet

The objective was to quantify the retention of digesta and evaluate the degradation of phytate or inositol hexakisphosphate (InsP(6)) and lower inositol phosphates (InsP?, InsP?, InsP?, and InsP?) in the stomach at different times after feeding pigs a fermented liquid diet with microbial phytase or a nonfermented diet with or without microbial phytase. Six barrows fitted with gastric cannulas were used. The experiment was a 3 × 3 Latin square with 3 pigs fed 3 diets during 3 wk in 2 replicates. Each experimental period lasted for 7 d, comprising 3 d of adaptation and 4 d of total collection of gastric digesta. For each pig, the digesta was collected once daily at 1, 2, 3, or 5 h after feeding the morning meal. A basal wheat- and barley-based diet was steam-pelleted at 90°C. The dietary treatments were a nonfermented basal diet (NF-BD), the NF-BD with microbial phytase (750 phytase units of phytase/kg, as-fed basis; NF-BD + phytase), and the NF-BD + phytase fermented for 17.5 h (F-BD + phytase). Gastric InsP?-P was not detected at all in pigs fed F-BD + phytase because of complete InsP? degradation during fermentation of the feed before feeding. Gastric InsP?-P decreased over time (P < 0.05) in pigs fed NF-BD and NF-BD + phytase. The decreases were 45, 54, 56, and 61 percentage points greater at 1, 2, 3, and 5 h, respectively, in pigs fed NF-BD + phytase compared with NF-BD. However, substantial amounts of InsP? still passed into the small intestine in pigs fed NF-BD + phytase, especially within the first hour (estimated to 17% of InsP?-P intake). The accumulation of lower inositol phosphates in gastric digesta was very small for all treatments and at all times because of a rapid and almost complete degradation. In conclusion, phytase addition to the nonfermented diet increased the degradation of gastric InsP?. However, considerable amounts of intact InsP? still passed into the small intestine because of a shortage of time for InsP? degradation in the stomach. Therefore, to increase the apparent digestibility of plant P in dry wheat- and barley-based diets, the development of phytases that can degrade InsP? effectively immediately after ingestion of the feed at an initial gastric pH from 6.5 to 5.0 is needed. Feeding F-BD + phytase compensated for the shortage of time because the InsP? degradation was completed during fermentation before feeding. The degradation of InsP? to InsP? is the bottleneck for plant P utilization in pigs because the degradation of the lower inositol phosphates is rapid and almost complete.     

Prevalence of gastrointestinal nematodes in growing pigs in Kabale District in Uganda

During the last 30 years, pig production in Uganda and neighbouring counties has increased markedly. Pigs are mainly kept as a source of income for small-scale farmers; however, the pig production is subject to several constraints, one of them being worm infections. A study was carried out in rural communities in Kabale District in the South Western part of Uganda in September and October 2007 in order to estimate the prevalence of gastrointestinal nematode parasites in pigs based on coprological examination. Fifty-six households were randomly selected and visited. Housing system and deworming history were recorded. Faeces was sampled from rectum of one to five pigs (age, 3–12 months) per household. A total of 106 pigs were examined coprologically of which 91% excreted nematode eggs. The following prevalences of nematode eggs were recorded: strongyles (89%), Ascaris suum (40%), Trichuris suis (17%) and spiruroid eggs (48%). On household level, rearing pigs on slatted floors in pens significantly reduced the faecal egg excretion of strongyle eggs with almost 80% (p = 0.010) and a significant interaction between floor type and anthelmintic treatment was found for spiruroids (p = 0.037). Fifteen T. suis egg positive pigs were selected for post-mortem examination of the gastrointestinal tract. The post-mortem examinations revealed that 93% pigs were infected with Oesophagostomum spp. (worm burden, min–max 10–2,180), 73% with A. suum (1–36), 67% with T. suis (6–58), and 20% with Hyostrongylus rubidus (worms not quantified). In general, nematode infections were widespread and polyparasitism common in pigs in Uganda. However, worm burdens were moderate which may be related to recent deworming or to the practice of rearing pigs on slatted floors in wooden elevated pens.     

Secondary renal tubular acidosis in a Hereford calf

A 3-month-old Hereford heifer calf was presented for lethargy. Blood gas analysis and plasma biochemical testing revealed severe metabolic acidosis, azotemia, hyponatremia, hyperchloremia, and normal anion gap. Results of a urinalysis were consistent with acute tubular necrosis with inadequate acidification of urine based on the degree of acidemia. Salmonella enterica serovar agona was cultured from both urine and feces. The calf was treated with intravenous polyionic fluids, bicarbonate, and antimicrobials. Acidosis and azotemia resolved, and 4 months following initial presentation the heifer was clinically normal.