Overview of Croatian poultry industry over the period 2003-2004

Peradarska je proizvodnja u Hrvatskoj tijekom 2003. i 2004. godine, unatoč gospodarskim poteškoćama, zadržala razinu iz prethodnih godina. Primje-ćuje se, međutim, restrukturiranje peradarskih proizvođača u smislu okrupnjavanja proizvodnje. Izgrađeno je i dosta novih nastambi za perad koje su opremljene najsuvremenijom opremom, a i dosta je starih nastambi adaptirano i opremljeno novim sustavima. Pojedini proizvođači kasne u primjeni novih tehnoloških rješenja i spoznaja, i to pretežito mali pro-izvođači koji će se vjerojatno izgubiti u tržišnoj utakmici. Analizirane smjese za hranidbu peradi u većini su slučajeva po kemijskom sastavu i higijenskim zahtjevima bile na zadovoljavajućoj razini. Dio smjesa za tov pilića ipak je sadržavao manju količinu proteina i metaboličke energije, pa se u takvim slučajevima ne iskorištavaju u potpunosti potencijali modernih hibrida tovnih pilića i tako gubi profit. Zdravlje se peradi u Hrvatskoj tijekom protekle dvije godine općenito može ocijeniti zadovoljavajućim. Zarazna bolest burze (gumborska bolest), koja je uzrokovala značajne gospodarske gubitke tijekom proteklih desetak godina, sada je u opadanju, no izrazito se povećala učestalost zarazne kržljavosti. S obzirom da se zarazna kržljavost sprečava ponajprije pridržavanjem temeljnih tehnoloških postulata peradarske proizvodnje, smatramo da ovoj bolesti ne bi smjelo biti mjesta u našoj intenzivnoj peradarskoj proizvodnji. Bakterije iz roda Salmonella su u 2004. izdvojene u daleko većem broju negoli u prethodne dvije godine, međutim najveći broj izolata odnosi se na salmonele iz skupine «C1». S. Enteritidis, koji je bio najčešći serovar tijekom proteklih desetak godina, zapravo je u laganom opadanju, dok je serovar S. Typhimurium nešto češće izdvajan. Učestalo izdvajanje salmonela iz skupine «C1» upućuje na njihovu nazočnost u smjesama za hranidbu peradi, čemu treba posvetiti posebnu pozornost.Poultry production in Croatia during 2003 and 2004 remained at the same level as in previous years despite the economical difficulties. However, restructuring of the industry to larger poultry producing companies was noted. Many new poultry farms with modern equipment have been built, and many old farms have been renewed and equipped with new systems. Some of the poultry producers are not up to date with management and husbandry, and these are primarily small producers who will probably disappear due to market competition. Analysed feed for poultry are generally at a satisfactory level regarding chemical composition and hygienic standards. Some broiler feed samples had a lower quantity of protein and energy, therefore genetic potential of the modern broiler hybrids is not fully exploited and profit is lost. Poultry health during the last two years can be generally estimated as satisfactory. Infectious bursal disease (Gumboro disease), which caused significant economic losses in the recent years, has decreased, but incidence of infectious stunting syndrome significantly increases. Infectious stunting syndrome is controlled primarily by basic management principles, so we assume that this disease should not be a problem in our poultry industry. Bacteria from Salmonella genus were isolated in 2004 in a greater number compared to two previous years, but most of the isolates belonged to “C1” group. S. Enteritidis, which was the predominant serovar during the last decade, slightly decreased, whereas S. Typhimurium serovar is increasing. Frequent isolation of “C1” group salmonellas implicates their presence in feed, and particular attention should be paid to this problem

T-2 toksin - pojavnost i toksičnost u peradi

T-2 toxin is the most toxic type A trichothecene mycotoxin. It is the secondary metabolite of the Fusarium fungi, and is common in grain and animal feed. Toxic effects have been shown both in experimental animals and in livestock. It has been implicated in several outbreaks of human mycotoxicoses. Toxic effects in poultry include inhibition of protein, DNA, and RNA synthesis, cytotoxicity, immunomodulation, cell lesions in the digestive tract, organs and skin, neural disturbances and low performance in poultry production (decreased weight gain, egg production, and hatchability). Concentrations of T-2 toxin in feed are usually low, and its immunosuppressive effects and secondary infections often make diagnosis difficult. If at the onset of the disease, a change in diet leads to health and performance improvements in animals, this may point to mycotoxin poisoning. Regular control of grain and feed samples is a valuable preventive measure, and it is accurate only if representative samples are tested. This article reviews the incidence and toxic effects of T-2 toxin in poultry.T-2 toksin je najtoksičniji predstavnik trikotecenskih mikotoksina tipa A. On je sekundarni produkt metabolizma plijesni roda Fusarium i često je prisutan u žitaricama i hrani za životinje. Štetni učinci uočeni su u eksperimentalnih životinja i životinja u uzgoju. On se povezuje s pojavom bolesti ljudi od mikotoksikoza. Učinci toksina u peradi su višestruki: inhibicija sinteze proteina, DNA i RNA, citotoksični učinak, imunomodulatorni učinak, oštećenje stanica probavnog sustava, organa i kože, živčani poremećaji te pad proizvodnih karakteristika u uzgoju peradi (slabiji prirast, pad nesivosti i valivosti). Koncentracije T-2 toksina u hrani redovito su vrlo malene, a zbog imunosupresivnog djelovanja toksina te istodobne sekundarne infekcije bolest se često teško dijagnosticira. Pri pojavi bolesti promjenom hrane može doći do poboljšanja zdravstvenog stanja, što tako|er upućuje na moguće trovanje mikotoksinima. Redovita kontrola uzoraka žitarica i hrane za životinje jedna je od preventivnih mjera, a detekcija mikotoksina u žitaricama i hrani pouzdana je samo ako se ispituje reprezentativan uzorak. U radu su opisani učestalost i toksični učinci T-2 toksina u peradi

Constitutive versus heat and biotic stress induced BVOC emissions in Pseudotsuga menziesii

Induced volatiles have been a focus of recent research, as not much is known of their emission behavior or atmospheric contribution. BVOC emissions were measured from Pseudotsuga menziesii saplings under natural environmental conditions, using a dynamic branch enclosure system and GC-MS for their analysis. We determined temperature and light dependency of the individual compounds, studied seasonality of the emissions and discuss the effect of heat stress in comparison with two specific biotic stresses that occurred naturally on the trees. A standardized emission rate of 6.8 μg g (dw) -1 h -1 for monoterpenes under stressed conditions was almost a magnitude higher than that obtained for healthy trees (0.8 ± 0.2 μg g (dw) -1 h -1), with higher beta factors characterizing the stressed trees. The response of the emissions to light intensity was different for the individual compounds, suggesting a distinct minimum light intensity to reach saturation. Heat stress changed the relative contribution of specific volatiles, with larger extent of increase of sesquiterpenes, methyl salicylate and linalool emissions compared to monoterpenes. Biotic stress kept low the emissions of sesquiterpenes, (E)-4,8-dimethyl-1,3,7-nonatriene and methylbutenol isomers, and increased the level of methyl salicylate and monoterpenes. The ratio of β-pinene/α-pinene was also found to be significantly enhanced from 1.3 to 2.4 and 3.2 for non-stressed, heat stressed and combined biotic and heat stressed, respectively

Clear link between drought stress, photosynthesis and biogenic volatile organic compounds in Fagus sylvatica L.

Direct plant stress sensing is the key for a quantitative understanding of drought stress effects on biogenic volatile organic compound (BVOC) emissions. A given level of drought stress might have a fundamentally different effect on the BVOC emissions of different plants. For the first time, we continuously quantified the level of drought stress in a young potted beech (Fagus sylvatica L.) with a linear variable displacement transducer (LVDT) installed at stem level in combination with simultaneous measurements of BVOC emissions and photosynthesis rates at leaf level. This continuous set of measurements allowed us to examine how beech alters its pattern of photosynthesis and carbon allocation to BVOC emissions (mainly monoterpenes, MTs) and radial stem growth during the development of drought stress. We observed an increasing-decreasing trend in the MT emissions as well as in the fraction of assimilated carbon re-emitted back into the atmosphere (ranging between 0.14 and 0.01%). We were able to link these dynamics to pronounced changes in radial stem growth, which served as a direct plant stress indicator. Interestingly, we detected a sudden burst in emission of a non-identified, non-MT BVOC species when drought stress was acute (i.e. pronounced negative stem growth). This burst might have been caused by a certain stress-related green leaf volatile, which disappeared immediately upon re-watering and thus the alleviation of drought stress. These results highlight that direct plant stress sensing creates opportunities to understand the overall complexity of stress-related BVOC emissions