<Emphasis Type="Italic">Fusarium</Emphasis> head blight incidence and detection of <Emphasis Type="Italic">Fusarium</Emphasis> toxins in wheat in relation to agronomic factors

We investigated incidences of Fusarium head blight (FHB) and concentrations of six mycotoxins (deoxynivalenol, nivalenol, 3-acetyldeoxynivalenol, T-2 toxin, HT-2 toxin and zearalenone) in wheat from 2010 to 2013. Field trials were conducted at the Experimental Station of Cultivar Testing in Chrz?stowo, Poland (53^o11’N, 17^o35’E). We examined the effects of four agronomic factors, including pre-crop type (corn, sugar beets and wheat), date of sowing (late autumn: November 8–December 9 or spring: March 29–April 19), fungicidal application (untreated or treated with two applications) and cultivar (Monsun, Cytra), on FHB index (FHBi) and mycotoxin levels in order to minimize the risk of wheat grain contamination by mycotoxins via integrated pest management methods. The dominant Fusarium species observed on wheat heads were F. culmorum, F. avenaceum (Gibberella avenacea) and F. graminearum (Gibberella zeae), at 21.1%, 17.2% and 7.1%, respectively. A monthly rainfall sum of 113.9 mm and a relatively low air temperature (monthly average 15.5 °C) resulted in the highest FHBi in untreated wheat (25.1%). Agronomic factors crucial for the FHB incidence were the pre-crop, fungicidal treatments and cultivar selection. In wheat planted after wheat or corn, the FHBi was higher compared with a pre-crop of sugar beet. A double application of fungicides at BBCH 30–32 with prothioconazole and spiroxamine and at a BBCH 65 with fluoxastrobin and prothioconazole effectively reduced the FHBi and mycotoxin concentrations, respectively, in grain. The cultivar ‘Cytra’ had a greater FHBi (10.4%) than ‘Monsun’ (4.6%), and grain infestations by Fusarium species were also greater in ‘Cytra’, at 16.5%, than in ‘Monsun’, at 11.2%. Untreated cv. Cytra grown after corn in spring produced grains with the highest amounts of the mycotoxins, deoxynivalenol, 3-acetyldeoxynivalenol, zearalenone and HT-2 (605, 103, 17.5 and 5.53 μg/kg, respectively). Total mycotoxin levels in wheat were correlated with five determinants: duration of the period between the end of flowering and the beginning of kernel abscission, FHBi, F. culmorum isolation, G. zeae isolation and Fusarium ratio (FR) as a % of total mould isolations. Although, the mean concentration of mycotoxins in grain did not exceed the maximum permissible values for unprocessed wheat our study suggests necessity to monitor and mitigate FHB risk for susceptible cultivars, when wheat spring sowing follows corn or wheat.     

Immunoexpression of Aromatase in Immature and Adult Males of the European Bison (Bison bonasus,Linnaeus 1758)

Based on recent literature dealing with the role of oestrogens in the male gonad, attempts were undertaken to reveal the site of aromatization within the testis of the European bison (Bison bonasus). Testes were collected from culled animals living in free‐ranging populations in Bialowieza Forest, Poland (nine males aged 8 months to 10 years). Moreover, to check for any alterations in the expression of testicular aromatase between American bison (Bison bison) and European bison, testes from one adult 10‐year‐old individual were also chosen for this study. For immunohistochemistry, 4% formaldehyde fixative was used. Both qualitative and quantitative evaluations of immunohistochemical staining were performed. Leydig cells, Sertoli cells and germ cells exhibited a positive immunoreaction for aromatase in testes of immature and sexually mature bison. A marked increase in aromatase expression was observed in three adult European individuals with impaired spermatogenesis. Consistent with recent data and those of our own, it might be suggested that the strong expression of aromatase negatively affects spermatogenic function in bison testes and may serve as a possible explanation of specific sperm defects observed in European bison bulls. On the contrary, one cannot exclude that differences in the aromatase immunoexpression levels are attributed to the homozygosity, the cause of frequent disease in European bison.     

Pharmacokinetics and tissue residue profiles of erythromycin in broiler chickens after different routes of administration

This study investigated the disposition kinetics and plasma availability of erythromycin in broiler chickens after single intravenous (i.v.), intramuscular (i.m.), subcutaneous (s.c.) and oral administrations (p.o.) of 30 mg kg(-1) b. wt. Tissue residue profiles were also studied after multiple intramuscular, subcutaneous, and oral administration of 30 mg kg(-1) b. wt., twice daily for three consecutive days. Plasma and tissue concentrations of erythromycin were determined using microbiological assay methods with Micrococcus luteus as the test organism. Following intravenous injection, plasma concentration-vs-time curves were best described by a two compartment open model. The decline in plasma drug concentration was bi-exponential with half-lives of (t(1/2alpha)) 0.19 h and (t(1/2beta)) 5.3 h for distribution and elimination phases, respectively. After intramuscular, subcutaneous and oral administration erythromycin at the same dose was detected in plasma at 10 min and reached its minimum level 8 h post-administration. The peak plasma concentration (Cmax) were 5.0, 5.3, and 6.9 microg x ml(-1) and were attained at 1.7, 1.4, and 1.3 h (Tmax), respectively. The elimination half-lives (T(1/2el)) were 3.9, 2.6, and 4.1 h and the mean residence times (MRT) were 3.5, 3.2, and 3.6 h, respectively. The systemic bioavailabilities were 92.5, 68.8, and 109.3%, respectively. In vitro protein binding percent of erythromycin in broiler plasma was ranged from 21 to 31%. The limit of quantification (LOQ) for the assay was 0.03 microg x ml(-1) in plasma and tissues. The tissue level concentrations were highest in the liver, and decreased in the following order: plasma > kidney > lung > muscle and heart. No erythromycin residues were detected in tissues and plasma after 24 h except in liver and kidney where it persisted during 48 h following intramuscular and oral administrations.     

Thermoregulation and Water Balance as Affected by Water and Food Restrictions in Sudanese Desert Goats Fed Good-quality and Poor-quality Diets

Nine desert goats were used in a 3 x 3 Latin square design in which they were subjected to (a) ad libitum water and food (control), (b) ad libitum food and water restricted to about 40% of the control, and (c) ad libitum water and restricted food (same amount as given to group b). Parameters measured were dry matter intake (DMI), water intake, rectal temperature (Tr), respiration rate (RR), water balance and body weight (BW) changes. The acute effects of the above treatments on these parameters were monitored during the dry summer using two types of feed. The ratio of DMI to water intake decreased (p < 0.01) due to water restriction but increased (p < 0.01) with Lucerne hay compared to grass hay. With both feeds, BW decreased (p < 0.01) with water restriction, with a further decrease (p < 0.01) observed with food restriction. The control group showed a higher (p < 0.01) gain with Lucerne hay than grass hay. Tr and RR increased (p < 0.01) from morning to afternoon; Tr decreased due to food restriction during both morning and afternoon with Lucerne hay (p < 0.05) and grass hay (p < 0.05), whereas RR decreased (p < 0.01) with both types of feeds. For all groups of animals, Tr was higher (p < 0.05) with Lucerne hay than with grass hay, this effect being more pronounced (p < 0.01) with the control group. With both feeds, water restriction decreased (p < 0.01) water turnover rate and evaporative losses, with decreased (p < 0.05) faecal losses observed in the water-restricted groups on Lucerne hay but higher (p < 0.05) losses of urine. The tolerance of desert goats to thermal stress and their coping with shortage of water and food depended on their capacity to lose heat through panting and cutenaous evaporation as well as their ability to concentrate urine.     

An improved radioimmunoassay for measurement of pepsinogen in porcine blood samples

The study was conducted to develop a sensitive and specific radioimmunoassay (RIA) for the measurement of pepsinogen in porcine serum, and to use this test for the determination of pepsinogen concentrations in serum samples from fetuses and pigs of different ages. Compared to a previously described RIA, major improvements were made concerning the use of specific polyclonal antibodies and the use of an appropriate buffer. The assay was able to detect pepsinogen concentrations of >/=0.2 ng/mL. The recovery of pepsinogen was close to 95%. The intra-assay coefficients of variations ranged between 3.9 and 7.5% whereas the interassay ranged between 8.8 and 11.9%. These percentages correspond to a satisfactory accuracy and reproducibility of the assay. No cross-reactions were observed with the main commercially available products of the aspartic proteases family except porcine pepsin cross-reacted over 62.5 microg/mL. Pepsinogen concentrations increased steadily with increasing age of the fetuses and the pigs (P<0.05). Pepsinogen concentrations (+/-SE) in fetuses of 90-100 (n=24) and 100-110 days of pregnancy (n=36) were 0.5+/-0.1 and 5.3+/-1.3 ng/mL, respectively. In pigs of 21, 98, and 213 days of age, the pepsinogen concentrations were 290.6+/-10.8, 343.1+/-17.9 and 383.5+/-15.3 ng/mL, respectively. The results demonstrate that RIA is accurate and can be used easily to assess pepsinogen concentrations in pig sera. The test may constitute a valuable tool in epidemiological surveys and in studies related to gastric diseases in pigs.