Metabolic and endocrine profiles and reproductive parameters in dairy cows under grazing conditions: effect of polymorphisms in somatotropic axis genes

<p>Abstract</p> <p>Background</p> <p>The present study hypothesized that GH-AluI and IGF-I-SnabI polymorphisms do change the metabolic/endocrine profiles in Holstein cows during the transition period, which in turn are associated with productive and reproductive parameters.</p> <p>Methods</p> <p>Holstein cows (Farm 1, primiparous cows, n = 110, and Farm 2, multiparous cows, n = 76) under grazing conditions were selected and GH and IGF-I genotypes were determined. Blood samples for metabolic/endocrine determinations were taken during the transition period and early lactation in both farms. Data was analyzed by farm using a repeated measures analyses including GH and IGF-I genotypes, days and interactions as fixed effects, sire and cow as random effects and calving date as covariate.</p> <p>Results and Discussion</p> <p>Frequencies of GH and IGF-I alleles were L:0.84, V:0.16 and A:0.60, B:0.40, respectively. The GH genotype was not associated with productive or reproductive variables, but interaction with days affected FCM yield in multiparous (farm 2) cows (LL yielded more than LV cows) in early lactation. The GH genotype affected NEFA and IGF-I concentrations in farm 1 (LV had higher NEFA and lower IGF-I than LL cows) suggesting a better energy status of LL cows.</p> <p>There was no effect of IGF-I genotype on productive variables, but a trend was found for FCM in farm 2 (AB cows yielded more than AA cows). IGF-I genotype affected calving first service interval in farm 1, and the interaction with days tended to affect FCM yield (AB cows had a shorter interval and yielded more FCM than BB cows). IGF-I genotype affected BHB, NEFA, and insulin concentrations in farm 1: primiparous BB cows had lower NEFA and BHB and higher insulin concentrations. In farm 2, there was no effect of IGF-I genotype, but there was an interaction with days on IGF-I concentration, suggesting a greater uncoupling somatropic axis in AB and BB than AA cows, being in accordance with greater FCM yield in AB cows.</p> <p>Conclusion</p> <p>The GH and IGF-I genotypes had no substantial effect on productive parameters, although IGF-I genotype affected calving-first service interval in primiparous cows. Besides, these genotypes may modify the endocrine/metabolic profiles of the transition dairy cow under grazing conditions.</p

The characteristics of the gasoline engine powered by E85

W artykule zaprezentowano metody sporządzania charakterystyk wtrysku paliwa podczas zasilania silnika benzyną i paliwami alternatywnymi. Przedstawiono kryteria zamienności paliw i wskazano na zależność dokładnego odwzorowania charakterystyk silnika na osiągi pojazdu.The paper presents a method of making the fuel injection characteristics of the combustion engine powered by gasoline and alternative fuels. Presents also criteria for interchangeability of fuels and pointed out the dependence of the exact mapping of the engine characteristics on vehicle performance

Technological and legal aspects of vehicles supplying by E85 fuel

Celem niniejszego artykułu jest zwrócenie uwagi na brak regulacji prawnych pozwalających bezpiecznie użytkować pojazdy, które zostały przystosowane do zasilania E85 poprzez montaż konwerterów. Omówiono wybrane ustawodawstwo dotyczące innych alternatywnych paliw dostępnych na polskim rynku i wykazano brak ich odpowiedników dla pojazdów poddanych konwersji na paliwo alkoholowe. Przedstawiono wymagania techniczne związane z wykorzystaniem E85 do zasilania nowoczesnych silników benzynowych. W celu uregulowania kwestii bezpieczeństwa i ekologii pojazdów przystosowywanych do zasilania E85 niezbędne będzie wprowadzenie odpowiednich regulacji prawnych, zarówno w Polsce jak i na poziomie Unii Europejskiej.The purpose of the article is to present the problem of non-existance legislation to allow safely use vehicles with installed the E85 converters. The selected regulations of different alternative fuels available in Poland was discussed. There isn't any similar legislation for vehicles converted to alcohol fuel. The technical requirements for using the E85 to power modern gasoline engines was analyzed. In order to regulate the safety and environmental performance of vehicles adapted to use the E85 will be necessary to introduce the relevant legislation, both in Poland and European Union

Studying a construction of pistons for the aircraft CI engine

This paper examines the selected constructions of piston for aircraft CI engines and discusses tendencies in a development of piston designs. The paper addresses the question of using new materials and coatings to improve quality of pistons and the study of heat transfer and methods to absorb heat from a piston by means of cooling ducts. The selected materials were examined in terms of their advantages and drawbacks. The paper discusses different shapes of piston heads and their impact on combustion as well as indicates other factors behind parameters of combustion and toxic emission like injector shape types, lubrication types and clearances in the combustion chamber

Modeling a fuel injector for a two-stroke diesel engine

This paper discusses the modeling of a fuel injector to be applied in a two-stroke diesel engine. A one-dimensional model of a diesel injector was modeled in the AVL Hydsim. The research assumption is that the combustion chamber will be supplied with one or two spray injectors with a defined number of nozzle holes. The diameter of the nozzle holes was calculated for the defined options to provide a correct fuel amount for idling and the maximum load. There was examined the fuel mass per injection and efficient flow area. The studies enabled us to optimize the injector nozzle, given the option of fuel injection into the combustion chamber to be followed

Reducing emissions from motor vehicles as a result of leak detection from combustion chamber

W artykule przedstawiono sposób identyfikacji zmiennej obecnej w transmisji diagnostycznej z gniazda OBD, która najlepiej charakteryzuje zużycie silnika wynikające z nieszczelności komory spalania. Udowodniono tym wpływ przebiegu pojazdu na wartość ciśnienia w kolektorze dolotowym podczas pracy na biegu jałowym. Wykazano ponadto istnienie zależności pomiędzy niesprawnością silnika a zwiększoną emisją regulowanych toksycznych składników spalin. Wprowadzenie w systemie diagnostyki pokładowej rozbudowanych algorytmów diagnozowania szczelności komory spalania może przyczynić się do wcześniejszej identyfikacji niesprawności silnika, a przez to do zmniejszenia emisji spalin.In the article was presented identification methodology of the parameter (presented in the OBD transmission) which characterizes in the best way leaks resulting from the combustion chamber. It has been proven that exist the impact of vehicle mileage on the pressure value in the intake manifold during idling operations. The results suggest a relationship between motor disability and increased emissions of regulated toxic components of exhaust gases. The introduction of sophisticated on-board diagnostic system testing algorithms of the combustion chamber may lead to earlier identification of engine failure and thereby reduce emissions