Rumen fermentation response to a direct-fed xylanase enzyme preparation from Thermomyces lanuginosus in sheep.

A study was conducted to obtain data on the effects of a fungal fibrolytic enzyme preparation (Rumino-zyme, with 250 FXU/g xylanase activities) from Thermomyces lanuginosus on some rumen fermentation parameters in sheep. Ruminal fluid samples were taken just before the morning feeding and then 2 h and 4 h after feeding. Xylanase activity, pH, concentration of ammonia and volatile fatty acids were measured. The enzyme supplementation did not affect the pH but increased the xylanase activity and the total VFA concentration of the rumen fluid. The molar proportion of acetate increased, propionate was not affected and butyrate decreased after enzyme administration. The concentration of ammonia also decreased after supplementation with the enzyme product. It can be concluded that the xylanase enzyme preparation from T. lanuginosus induced favourable changes in the major rumen fermentation parameters in sheep.

Effects of a non-starch polysaccharidase enzyme preparation from Thermomyces lanuginosus on energy and protein metabolism and milk yield of dairy cattle.

Non-starch polysaccharides (NSPs) form an integral part of the cell walls in plants and represent considerable available energy when degraded into absorbable mono-, di-, tri- and oligosaccharides. The ruminal microflora hydrolyses a good part of NSPs, however, recently there have been attempts to enhance the rate of utilisation by using external polysaccharidase enzymes. In the present study the effects of an enzyme preparation (Rumino-Zyme) high in xylanase activity were studied on ruminal volatile fatty acid (VFA) concentration, parameters of energy and protein metabolism, milk yield, feed conversion ratio (FCR) and body condition score of high-yielding dairy cows. A lignolytic enzyme preparation produced by the thermophilic fungus Thermomyces lanuginosus was applied in the present experiment and fed to dairy cows at 34 g/day dosage in the period between calving and the 110th day of lactation. This preparation increased VFA concentration in the rumen from about 32 days after calving and onward. Increased VFA concentration was followed by an about 5 to 10% increase in milk production and an almost 0.1% increase in butterfat production. Increased VFA concentration produced more balanced energy metabolism in the experimental cows as indicated by the lower incidence rate of hyperketonaemia, and lower acetoacetic acid and non-esterified fatty acid (NEFA) concentration in the blood of the experimental cows. Aspartate aminotransferase (AST) activity was tendentiously higher in the control group and the proportion of cows that had AST activity higher than 100 U/l was also higher in the control group. Both control and experimental cows showed balanced protein and acid-base metabolism throughout the experiment. Enhanced VFA concentration contributed to an improvement in energy balance in the experimental cows with a resultant improvement of feed intake and feed utilisation. Due to the more balanced energy metabolism postparturient body condition loss of the treated cows was reduced.

Characterisation and effects of a xylanase enzyme preparation extracted from Thermomyces lanuginosus cultures.

This paper describes the production of an enzyme preparation from the fungus Thermomyces lanuginosus. Thermal resistance, pH stability and lignocellulolytic activity of the enzyme preparation high in xylanase were studied on a variety of grains and forages. The enzyme preparation preserved more than 70% of its original xylanase activity for 4 and 1 h at 60 and 70 degrees C, respectively. The xylanase activity remained over 80% when the preparation was incubated for 30 min at pH 4.5. In vitro digestibility studies indicated that the enzyme digested 7.5, 8.5 and 8.0% of the dry matter (DM) of barley meal, wheat bran and oat meal samples, respectively. When applying 60-min incubation, 7.5, 7.3 and 8.4% of DM of the oat straw, alfalfa hay and triticale straw was digested, respectively. When the time of digestion was increased to 360 min, the sunflower hull showed 15.8% DM digestibility.

Evaluation of mycotoxin-contaminated cereals for their use in animal feeds in Hungary.

In the period between December 5, 1991 and September 17, 1998, 760 maize, 367 wheat, 119 soybean, 222 barley, 85 bran, 32 triticale, 60 oat, 14 rye and 22 sunflower samples were investigated for the presence and concentration of seven fusariotoxins (T-2 toxin, zearalenone, deoxynivalenol, nivalenol, diacetoxyscirpenol, HT-2 toxin, fusarenone-X) and OTA. The comparison of analytical data with those of the relevant literature revealed that although the incidence rate and/or concentration of Fusarium mycotoxins and OTA in Hungarian-grown cereals is occasionally considerable, the position of the country is not worse that the average of countries. Our findings indicate that soybean tends to be good substrate for trichothecene-producing fungi and the rate of contamination is regarded as substantial. The commodities were assorted into one of three quality categories. The proportion of objectionable samples was only 3.0, 2.2, 2.3 and 1.7% in maize, wheat, barley and soybean samples, respectively. However, this low rate of objection might still be a source of great economic loss. The proportion of objectionable samples was much higher in the case of bran, oat and triticale (7.1, 6.7, and 6.3%, respectively). The results of the present investigation indicate a need for regular screening for mycotoxins of importance and individual appraisal of each commodity from the point of their use in animal feeds.

Effect of dietary T-2 fusariotoxin concentrations on the health and production of white Pekin duck broilers.

The effects of different dietary levels of T-2 toxin on production, biological, immunological, and pathological parameters of growing white Pekin ducks were studied to establish the "no effect" dietary concentration of, and "no effect" exposure time to, pure T-2 toxin. Day-old white Pekin ducks were randomly allotted to nine groups of 10 ducks each. One group served as a control, and no mycotoxin was added to its feed. The feeds of the experimental groups were supplemented with 0.2, 0.4, 0.6, 0.8, 1.0, 2.0, 3.0, and 4.0 mg purified T-2 toxin/kg, respectively, from Day 1 until Day 49 of the experiment. Dermatotoxic oral lesions developed in most experimental ducks within 2 d after the start of feeding T-2 toxin-contaminated feeds. The gradual disappearance of macroscopic signs indicated the development of tolerance in groups treated with the lower T-2 toxin content. No repair was found in the 3 and 4 mg/kg groups. Dietary concentrations of T-2 toxin below 0.4 mg/kg had no effect on the average weekly weight gain in the first 6 wk, but a severe decrease was found in the last week of the experiment. The 0.6 mg/kg dietary T-2 toxin had no effect on weight gain in the first 3 wk. At Week 4 and later, the weekly weight gain was significantly reduced, and the final live weight of this group was also significantly lower than that of the control. Dietary T-2 concentrations of 1 mg/kg and greater uniformly depressed growth rate. Only the 3 and 4 mg/kg groups refused feed during the first week. From Week 3 on, the feed intakes of the 0.6 to 4 mg/kg groups were usually less than that of the control group, indicating feed refusal. Serum and plasma chemical values and hematological parameters failed to show dose-dependent effects. The blastogenic response of lymphocytes to nonspecific and specific mitogens was distinctly impaired by the T-2 toxin at all levels in the feed. In the 3 and 4 mg/kg groups, the histological examination revealed lymphocyte depletion in the spleen and bursa of Fabricius.

Effect of various levels of T-2 toxin on the clinical status, performance and metabolism of growing pigs.

In two sets of experiments eight groups of seven-week-old pigs weighing about 9 kg were fed for three weeks a prestarter that contained 0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 10.0 or 15.0 mg/kg of highly purified T-2 toxin. The feed of the two control groups was free from T-2 toxin. Average daily intakes of toxin by the pigs were 0.38, 0.81, 1.24, 1.43, 0.93, 0.81, 0.99 and 2.5 mg, respectively. The weight gains, the feed intakes, the extent of feed refusal, the parameters of energy and protein metabolism and the serum concentrations of calcium, inorganic phosphorus and magnesium were affected to different extents by the different doses of T-2 toxin, but the data indicated that feed consumption was reduced and the activity of aspartate aminotransferase was increased by the smallest amount of T-2 toxin tested.

Effect of various levels of T-2 toxin in the immune system of growing pigs.

Four groups of seven-week-old pigs weighing about 9 kg were fed for three weeks a prestarter that contained 0.5, 1.0, 2.0 or 3.0 mg/kg of highly purified T-2 toxin. The average daily intakes of toxin by the pigs were 0.38, 0.81, 1.24 and 1.43 mg, respectively. The experimental and control pigs were immunised with 5 ml aluminum hydroxide gel-absorbed purified horse globulin on the first and fourth days of the treatment period. Blood samples were withdrawn on days 7, 14 and 21 and used for the determination of the titre of anti-horse globulin antibody, for an in vitro lymphocyte proliferation test, using purified horse globulin, phytohaemagglutinin and concanavalin-A and for determinations of the immune complex, the cytotoxic reaction and the phagocytic activity and phagocytic index of circulating granulocytes. The samples taken on day 21 were also used to determine the erythrocyte count, the mean cell volume of the erythrocytes, the haematocrit, the blood haemoglobin concentration, the leucocyte count and the proportion of T lymphocytes. At the end of the experiment samples were taken from the thymus, spleen and mesenteric lymph nodes for histological examination. The diets that contained 2 and 3 mg T-2 toxin/kg caused a significant decrease in the red blood cell count, the mean corpuscular volume and the haemoglobin concentration. A significant decrease in the leucocyte count and the proportion of T lymphocytes was observed in all the treatment groups. There were also dose-dependent, significant decreases in antibody formation and in the blastogenic transformation of lymphocytes, and mild to moderate reactive processes were observed histologically in the lymphoid organs.

Interaction between immunity to Bordetella bronchiseptica and infection of pig herds by Bordetella bronchiseptica and Pasteurella multocida.

The dynamics of toxigenic Bordetella bronchiseptica and Pasteurella multocida infection and the B. bronchiseptica specific antibody content of the blood and nasal secretion were studied in three Hungarian and three Dutch pig herds. In both countries, the studies involved young sows that had farrowed once or twice (YS), old sows that had farrowed more than four times (OS), and their piglets. The results indicate that Dutch sows are characterized by a lower prevalence of B. bronchiseptica and P. multocida infection than Hungarian sows. In Dutch sows and in their piglets, the rate of P. multocida infection was higher than that of B. bronchiseptica infection. The opposite was found for the Hungarian sows and their piglets. B. bronchiseptica infection commenced at 3 and 4 weeks of age in piglets of young and old Dutch sows, respectively, followed by the emergence of P. multocida infection at 5 (YS) and 6 weeks of age (OS). In Hungarian piglets, B. bronchiseptica infection was first demonstrable at 1 (YS) and 3 (OS) while P. multocida infection at 3 (YS) and 5 (OS) weeks of age. The serological tests demonstrated higher B. bronchiseptica specific antibody levels in the Dutch sows and piglets as compared to the Hungarian ones. According to the ELISA results, the levels of IgA and IgG in the serum and those of sIgA, IgA and IgG in the nasal secretion of Dutch sows were significantly (p < 0.001) higher in the Dutch than in the Hungarian piglets up to 3 and 4 weeks of age, respectively.

Interaction between Bordetella bronchiseptica and toxigenic Pasteurella multocida on the nasal mucosa of SPF piglets.

The interaction between Bordetella bronchiseptica and type D toxigenic Pasteurella multocida was studied in five groups of 4 specific-pathogen-free (SPF) piglets each. At 28 days of age, piglets of groups 3 and 4 were inoculated into both nostrils with 10(8) colony-forming-units (CFU) of a non-dermonecrotic toxin (DNT)-producing, phase I strain of B. bronchiseptica. Piglets of groups 1 and 3 were treated intranasally with a sonic extract of the non-toxic strain of B. bronchiseptica and those of groups 2 and 4 with B. bronchiseptica DNT into the left nostril. Sonic extract and DNT treatment was started at 33 days of age and lasted for 5 days. Piglets of group 5 served as controls. At the age of 37 days, piglets of all groups except group 5 were inoculated into both nostrils with 5 x 10(7) CFU of toxigenic P. multocida. At slaughter at 50 days of age, P. multocida was recovered from the left nasal cavity of 3 piglets of group 2 and all piglets of group 4. In piglets inoculated with B. bronchiseptica DNT the mucosal epithelial cells of the left nasal cavity showed loss of cilia, regressive lesions such as vacuolation, karyopycnosis and necrosis, hypertrophy of the epithelium, infiltration of the epithelium and submucosa by inflammatory cells, could also be seen. The results suggest that action of the B. bronchiseptica DNT on the nasal mucosa is a precondition of the growth of P. multocida in the nasal cavity.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical and pathological effects of the dermonecrotic toxin of Bordetella bronchiseptica and Pasteurella multocida in specific-pathogen-free piglets.

The role of dermonecrotic toxin (DNT) of Bordetella bronchiseptica and Pasteurella multocida, purified by repeated chromatography in Sephacryl S-200 gel, in the pathogenesis of atrophic rhinitis (AR) of swine was studied bacteriologically, clinically and pathologically. Two-week-old specific pathogen-free (SPF) piglets were parenterally treated with 30 micrograms of DNT 3 times at 2-day interval and 7-week-old piglets were treated with 15 micrograms of DNT twice a week for 5 weeks. In 2- to 3-week-old piglets, both B. bronchiseptica DNT and P. multocida DNT produced nasal turbinate lesions with similar severity, characterized by damage of the cilia, epithelial metaplasia, intensive proliferation of osteoblasts, regressive changes, and diffuse osteocytic osteolysis. In 7- to 12-week-old piglets, treatment with B. bronchiseptica DNT failed to produce progressive changes in the nasal turbinates. Histopathological examination revealed osteogenic processes and osteoid synthesis besides the proliferation of osteoblasts and mild osteocytic osteolysis. Moreover, severe gross pathological lesions developed in the stomach, liver, kidneys, and lymphoid organs. The piglets' appetite and body weight gain gradually decreased during the DNT treatment and in the last week when the toxic signs appeared. Treatment of 7- to 12-week-old piglets with P. multocida DNT resulted in progressive AR. Histopathologically, diffuse osteocytic osteolysis was observed in the nasal turbinates. Neither clinical signs nor pathological lesions of the visceral organs developed in these piglets. The authors emphasize that the DNT of B. bronchiseptica basically differs from that of P. multocida in biological properties, though there are certain similarities between the DNTs.

The influence of growth conditions of Pasteurella multocida on its ability to colonise the nasal mucosa of SPF piglets.

Colonisation of type D Pasteurella multocida was studied in five groups of seven SPF piglets each. Piglets of Group 1 were kept together with seven 5-week-old piglets obtained from a large herd infected with toxigenic P. multocida for 16 weeks (contact infection). These piglets were made free from toxigenic Bordetella bronchiseptica by local immunisation. Piglets of Group 2 were inoculated with 5 x 10(7) colony-forming units (cfu) of P. multocida washed from the nasal mucosa of piglets free from toxigenic B. bronchiseptica with fetal calf serum. Piglets of Group 3 were inoculated intranasally with 5 x 10(7) cfu of P. multocida washed from yeast-extract proteose-peptone cystine (YPC)-blood agar with fetal calf serum. Piglets of Group 4 were inoculated with 5 x 10(7) cfu of P. multocida grown in a YPC-based broth without blood. Piglets of Group 5 served as controls. The piglets of Group 1 did not contract P. multocida infection from infected contact piglets. After a single inoculation one of four, while after three inoculations two of three piglets of Group 2 became infected by P. multocida. After a single inoculation none of four, while after three inoculations one of three piglets of Group 3 were colonised by P. multocida. Both single and repeated inoculation failed in piglets of Group 4.

Effect of selenium, vitamin E and riboflavin supplementation of the feed on the humoral and cell-mediated immune responses of growing pigs.

The feed of weaned piglets of Hungarian Large White X Duroc and Dutch Landrace X Duroc genotype was supplemented with 0.5 mg selenium, 50, 100 or 150 mg vitamin E, and 2.5 or 5 mg riboflavin per kg. Feed supplementation enhanced the cytotoxic reaction and elevated the antibody titres produced against purified horse gamma globulin antigen. However, as compared to the control the differences were not significant. Feed supplementation exerted a beneficial, though varying, influence on the indices of cell-mediated immunity. The proportion of rosette-forming cells and blastogenic transformation induced by specific (horse globulin) and nonspecific (phytohaemagglutinin, PHA) mitogens underwent the most expressed and most significant increase in pigs fed 5 mg selenium, 100 mg vitamin E and 5 mg riboflavin per kg of feed. On the other hand, feed supplementation failed to enhance the responsiveness to intradermal PHA (type IV allergic reaction).