Pre-weaning eating activity and morphological parameters in the small and large intestine of piglets

The effect of pre-weaning eating activity on the intestinal morphology in piglets was investigated on the day of weaning and 5 days post-weaning. The eating activity of each piglet was recorded by means of direct observations. On day 5 post-weaning the villous heights were reduced and the crypt depths were increased irrespective of the pre-weaning eating activity. In the caecum and colon the crypt depth was increased post-weaning and no effect of pre-weaning eating activity was observed. The muscle thickness in the small intestine did not change during the immediate post-weaning period whereas the muscle thickness in the large intestine was doubled in the same period. In conclusion, pre-weaning eating activity did not affect the structural alterations of the small and large intestine. However, the actual number of piglets consuming creep feed prior to weaning was low and the eating activity was highly variable. Therefore, more or later weaned piglets may be needed to show effects of pre-weaning eating activity.     

Interaction between powdery mildew and barley with mlo5 mildew resistance

Powdery mildew infection of barley with the mlo5 barley powdery mildew resistance gene was examined, using near-isogenic barley lines, with and without mlo5 resistance, and two near-isogenic powdery mildew isolates, HL3/5 and GE3 with high (virulent) or low (avirulent) penetration efficiency on the resistant barley line. In all isolate–host combinations (except GE3 on the resistant barley line), frequency of haustorium formation increased significantly from zero at 11 h after inoculation to a maximum by 13 h, and there was no subsequent increase up to 24 h. In the susceptible barley line, 27% of appressoria from both isolates formed haustoria. Although this was significantly higher than the frequency of haustorium formation (18%) of HL3/5 on the resistant barley line, HL3/5 was much more successful than GE3 (frequency of haustorium formation less than 1%). The fact that HL3/5 did not possess a generally higher ability to penetrate successfully to form haustoria on the susceptible barley line, indicates that HL3/5 did not overcome the mlo5 resistance by being generally more vigorous. In the resistant barley line, papillae were larger than in the susceptible line; however, both isolates were associated with papillae of the same diameter at the time of penetration. We suggest that the mlo5 resistant barley line confers two different forms of resistance: isolate-specific and isolate-nonspecific.     

Response of Sorghum to Abiotic Stresses: A Review

Sorghum [(Sorghum bicolor L.) Moench] is a highly productive crop plant, which can be used for alternative energy resource, human food, livestock feed or industrial purposes. The biomass of sorghum can be utilized as solid fuel via thermochemical routes or as a carbohydrate substrate via fermentation processes. The plant has a great adaptation potential to drought, high salinity and high temperature, which are important characteristics of genotypes growing in extreme environments. However, the climate change in the 21st century may bring about new challenges in the cultivated areas. In this review, we summarize the most recent literature about the responses of sorghum to the most important abiotic stresses: nutrient deficiency, aluminium stress, drought, high salinity, waterlogging or temperature stress the plants have to cope with during cultivation. The advanced molecular and system biological tools provide new opportunities for breeders to select stress‐tolerant and high‐yielding cultivars.     

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.     

Serotypes of Pasteurella haemolytica and Pasteurella trehalosi isolated from farm animals in Hungary.

The biochemical and serological characteristics of 486 P. haemolytica and 31 P. trehalosi strains (517 in total) isolated from different lesions of cattle, sheep, goats, pigs and poultry were examined. A total of 476 P. haemolytica strains (97.9%) showed the characteristics typical of the former biotype A of P. haemolytica, while 10 isolates (2.1%), all from poultry, could not be biotyped. A total of 481 strains (93.0%) could be assigned to one of the 17 serotypes of P. haemolytica-P. trehalosi and 36 strains (7.0%) could not. The majority (83.6%) of the cattle isolates were serotypes A1 and A2. Among strains isolated from sheep all serotypes of P. haemolytica could be identified with the exception of A14, but serotypes A1, A2, A6, A8 and A5 were the most frequent. The overwhelming majority (94%) of the caprine isolates were A2, other serotypes occurred only sporadically. The pig isolates, which could be isolated only very rarely, represented different serotypes, while none of the 10 strains isolated from poultry could be biotyped or serotyped.     

The effect of selected preparations for the protection of draft horses against dipterous blood-sucking insects

Dipterous blood-sucking insects (horseflies, black flies, gnats, midges) have negative impacts on the performance of draught horses in forest enterprises. For the protection of these animals, the following preparations were applied at the interval of 24 hours: diethyltoluamide, Oxamat (N,N-diethyloxamine acid, USSR) and Stomoxin (synthetic pyrethroid, product of the firm Wellcome, England). In the course of 66 working days, the performance of test animals treated with 10% water emulsion of diethyltoluamide increased by 49.25 cu. m. of skidded wood, i.e. by 0.74 cu. m. wood per horse/day (21.65%), as compared with the control group. The daily savings of prime costs per test horse/day made 16.99 Kcs (Czechoslovak crowns). In comparison with the control group, the performance of horses treated with 5% water emulsion of Oxamat increased by 85.50 cu. m. wood, i.e. by 1.29 cu. m. wood per horse/day (38.00%). Stomoxin at the concentration of 0.05% acted as a good insecticide but had no marked repellent effect. The results of this study document that the production of effective repellents should be introduced in the Czechoslovak Socialist Republic.     

Survey of Actinobacillus (Haemophilus) pleuropneumoniae infection in swine by different methods

Lung and serum samples from pigs that died or were emergency-slaughtered in a pooled, conventional fattening herd were examined to survey Actinobacillus pleuro-pneumoniae infection and to compare the sensitivity of different testing methods. A total of 110 lungs were used for cultural isolation of the agent and direct immunofluorescence (IF) of impression smears. Boiled lung suspensions were tested by coagglutination (Co-A) and agar gel precipitation (AGP). Eighty-seven sera were tested along with lung samples from the same pigs. The lungs yielded a varied bacterial flora most often containing Pasteurella multocida and less frequently Actinomyces (Corynebacterium) pyogenes, E. coli and Salmonella. A. pleuropneumoniae was isolated from 30 lungs: from 22 lungs it grew out in pure culture, from 7 as mixed culture with P. multocida and from 1 as mixed culture with A. pyogenes. The number of positive samples obtained by the different methods was as follows: coagglutination test (with boiled lung suspensions): 63 (57.3%); immunofluorescence: 43 (39.2%); AGP test (with serum): 31 (35.6%); AFP test (with boiled lung suspension): 25 (22.7%). A total of 23 samples (20.7%) were negative by all serological tests and by cultural isolation. Most samples gave positive results by two or more tests while 26 samples only by one test (most often, on 13 occasions, by the Co-A test). The Co-A test detected antigenic components of serotypes that have not been isolated in Hungary so far. This indicates that it is not enough to test one strain from a given lung sample: several colonies must be cultured and serotyped.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characteristics of paramyxoviruses isolated from pigeons in Czechoslovakia

Nine strains of paramyxovirus isolated from racing pigeons in southern Bohemia, Moravia and western Slovakia in 1983 were identified by the haemagglutination-inhibition test with antisera to seven types of paramyxovirus and three types of influenza A virus as PMV-1, Newcastle disease virus, in all cases. The haemagglutination activity and pathogenicity of the isolates for chicken embryos, chicken fibroblast cultures, and chickens of different age were determined. The mean death time of chicken embryos (MDT/MLD) was 52.8 to 95.4 h, the average being 75.7 h. The intracerebral pathogenicity index (ICPI8) was on an average 1.42 +/- 0.10 (P = 0.95). Experimental infection of chickens at the age of one, two, three and eight weeks did not cause any clinical disease but increased the level of haemagglutination-inhibiting (HI) serum antibodies up to 1 : 256 within three weeks. The course of heat inactivation of pigeon viruses at the temperature of 56 degrees C was practically identical with the inactivation of the velogenic viscerotropic strain California/1082/71. On the basis of the results, the pigeon isolates may be considered the Newcastle disease virus of velogenic viscerotropic type whose pathogenicity for chickens has been reduced to the level of mesogenic strains by long-time passaging in pigeons.