PoznanUniversity of Life science
PoznanUniversity of Life science
Nowicki S.,PoznanUniversity of Life science |
Przysiecki P.,State Higher Vocational School in Leszno |
Filistowicz A.,State Higher Vocational School in Leszno |
Potkanski A.,University of Life Sciences in Poznań |
And 2 more authors.
Folia Biologica (Poland) | Year: 2014
The study investigated the effect of vegetable and animal fat in the feed ration on the fatty acid profile of reserve fat in the arctic fox. Varying proportions of saturated and unsaturated fats in the feed ration comprised the experimental factor. In order to differentiate contents of saturated and unsaturated fatty acids in the experimental feed rations, various percentages of rapeseed oil and turkey fat were applied. The subcutaneous and circum-organal fat in this study differed considerably in terms of contents of individual fatty acids and between individual groups of acids. The circum-organal fat contained much higher amounts of unsaturated acids, but at the same time it was characterized by a lower amount of monounsaturated acids. Significant differences were also found in the contents of as many as 11 fatty acids. Recorded results indicate a potential modification of reserve fat in the arctic fox, a model representative of carnivorous animals (Carnivora). The possibility of the partial substitution of animal fat with vegetable oil (rape oil) in the nutritive diet of artic foxes was confirmed. © Institute of Systematics and Evolution of Animals, PAS, Kraków, 2014.
Kurek P.,Polish Academy of Sciences |
Steppa R.,PoznanUniversity of Life science |
Grzywaczewski G.,Lublin University of Life Sciences |
Tryjanowski P.,University of Life Sciences in Poznań
Plant, Soil and Environment | Year: 2016
This study aimed at investigating the species composition and richness of the flora of abandoned sheep pens in comparison to their immediate neighbourhood. Field research was conducted in the Wielkopolska province of western Poland on 25 circular plots (20 m2) located in the middle of abandoned pens within sheep farms, paired with 25 reference plots established in nearby grasslands. Physicochemical properties of the topsoil were modified considerably by sheep in the past, so some effects continue to this day. Abandoned sheep pens did not differ significantly in plant species richness from control plots, but Urtica dioica, Galium aparine and Rumex obtusifolius, were significantly associated with sheep pens. Similar values of Shannon index and the low Jaccard index of similarity between plot types indicate that although these habitats are not richer in plant species, they are refuges of some characteristic plant species, which are absent or infrequent in neighbouring habitats. Moreover, the changes in physicochemical properties of the soil (higher average ammonium NH4 +-N and nitrate NO3 –-N content) and vegetation structure are very deep, as they have persisted for 25 years. © 2015 Czech Academy of Agricultural Sciences. All rights reserved.
Piekarska-Boniecka H.,PoznanUniversity of Life science |
Siatkowski I.,PoznanUniversity of Life science |
Zyprych J.,PoznanUniversity of Life science
Acta Scientiarum Polonorum, Hortorum Cultus | Year: 2010
The aim of the paper is to construct a model which describes the life expectancy of privet sawfly females (Macrophya punctumalbum L.), including additional information on the number of eggs. The data on life expectancy of females and their fertility were obtained in the course of research on the bionomy of the privet sawfly. A variety of discrete distributions to modelling the lengths of life was provided, namely: the Poisson Distribution, the Negative Binomial Distribution and the Poisson-inverse Gaussian Distribution. The analysis the above distributions were applied along with the GAMLSS (Generalized Additive Models for Location, Scale and Shape) and the resulting models were compared with the use of the Global Deviance criterion, the Akaike information criterion and the Schwarz Bayesian criterion. For the best model the expected value and the standard deviation were defined. The profile deviance plot of this parameters, analysis of the residuals, kernel density and Q-Q plot are presented, too. All analyses were performed in R with the GAMLSS package.
Fraszczak B.,PoznanUniversity of Life science
Acta Scientiarum Polonorum, Hortorum Cultus | Year: 2012
Temperature and light are important factors determining growth and development of plants. The difference between day and night temperature (DIF - defined as day temperature minus night temperature) influences plant morphology in a wide range of species. In this study, the effect of photoperiod and DIF on stem elongation and growth of dill plants was investigated. The first experiment included a comparison of different temperatures between day and night (DIF-5 - 20/25°C, DIF0 - 20°C and 25°C, DIF+5 - 25/20°C) for a 16-h photoperiod. The second experiment comprised the photoperiod of 16 and 24 hours for two constant temperatures - 20 and 25°C. Significant differences between DIF+5 and DIF-5 were observed in the case of plant height. Elongation growth was enhanced by positive DIF and was inhibited by negative DIF, although the strongest stem elongation inhibition was recorded at the temperature of 25°C and a 16-h photoperiod. Leaf area was greatly affected by the temperature and DIF, but only slightly influenced by the photoperiod. Leaf area in DIF-5 was smaller than that in DIF+5 or 0 (20°C). The highest essential oil content in the herbage was recorded for a constant temperature of 25°C as well as 20°C and a 24-hour photoperiod.
Gaj R.,University of Life Sciences in Poznań |
Gorski D.,Institute of Plant Protection National Research Institute |
Przybyl J.,PoznanUniversity of Life science
Journal of Elementology | Year: 2013
This study was conducted in 2007-2010, on a farm near OErem (south of Poznañ, Poland). A field experiment was set up in a randomized block design with four replications for each combination tested. The effects of differentiated rates of phosphorous and potassium applied together with a fixed level of nitrogen and magnesium fertilization were investigated. During the experiment, the winter wheat grain yields were high and significantly different between both between fertilizer treatments and when compared with the control. Correlation analysis on relationships between grain yield and nutrient content in wheat leaves at the beginning of stem elongation stage (BBCH31) showed significant relationships for phosphorous, calcium, magnesium, zinc and manganese. Regression analysis proved that the content of zinc in leaves at the BBCH31 stage was the main factor which determined winter wheat grain yield. Furthermore, mineral fertilization significantly increased the content of protein and gluten when compared with the control objects, whereas no significant differences were observed among the fertilized objects. Statistically significant relationships were found between leaf content of N, P, Mg, Zn and Mn at BBCH31 and the accumulation of protein and gluten in wheat grain. Protein and gluten in grain depended on the content of magnesium in leaves at the beginning of stem elongation stage. Weather conditions as a factor significantly influenced grain size uniformity while mineral fertilization had no influence on this trait.