The objective of this study were 2 fold: to determine whether the weaning (abrupt transition from liquid to solid diet) at the age of 90 days causes stress in buffalo calves, and if so, to alleviate the negative effect of stress by chromium picolinate supplementation (400 μg daily). All buffalo calves were separated from their mothers immediately after birth. Chromium supplementation started 3 days before the weaning and was terminated 5 days later. Plasma cholesterol and indol levels declined significantly after weaning in both groups. Both the weaning and supplemental chromium had no effect on plasma urea level. Our results indicate that when the negative emotional arousal, caused by the interruption of the physical contact mother – calf, is avoided, as it is in our case, then the abrupt transition from liquid to solid feed at 90 d of age has no stress-inducing effect. Supplemental chromium reduced plasma cortisol levels both before and following the weaning, but had no significant effect on the determined metabolites since its effect is more pronounced during extreme stress load

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Abstract. Data from different multi-environmental trails (MET) were analysed, including different number of varieties, number of locations and different research periods. The first experiment (24 PhD) included 24 wheat varieties that were studied in five locations of the country over a period of four years (2009-2012). The second field experiment (40 ABC) consists of 40 new advanced wheat lines and cultivars, which were studied in three locations over a three-year period (2017-2019). The grain yield datasets from the two experiments were used to make a direct comparison of various statistical parameters to assess the genotype stability against the background of significant growing conditions. The study involves the use of several statistical packages that are specialized for this purpose. Based on the ranking assessment of the values of each statistical parameter, a critical analysis was made of its relationship with the yield, for each dataset separately. For this purpose, the possibilities of correlation, principal component and cluster analyses were used. Parameters for which information differs between datasets or between statistical packages are removed from the analysis list. The final set of 31 parameters was analysed according to the set goal, after a statistically justified possibility to merge the two datasets. Most of the rank parameters do not show correlation with grain yield. The units are the parameters, the correlation of which is either positive (Pi, Ysi, TOP, λ) or, respectively, negative (DJi, NP(1), CVi]). The analysis of the data through different statistical approaches shows that the parameters correspond to the dynamic concept of stability assessment. Only one of the parameters (θi) is related to static stability assessment. In the presence of many more effective than it, it should not be applied because it is an exception from the analysed group. The groups of parameters of the regression coefficient (bi), the deviation from the regression line (s2di), ecovalence (W2i) and the stability variance (σ²i), give objective information about the behaviour of the variety in environmental conditions and it is not influenced by software. Some of the non-parametric [S(i) NP(i)] assessment methods provide diametrically opposed information for stability because of differences arising from either the dataset or the software used. Suitable for stability assessment are non-parametric approaches - [S(1) and S(2)], which is fully confirmed by the three software packages. Each of the used software packages contains a set of parameters, the application of which as a set gives correct information about all aspects of the wheat stability

Abstract. Wheat is a crop with a very long growing season, during which it is subjected to prolonged exposure to many environmental factors. For this reason, the interaction of genotype with conditions is very common for any character of wheat. This study aims to determine whether the grain yield is affected by the change of the ear emergence date (EED) in various environments. In a four-year period, 30 current for national real grain production winter wheat varieties were studied. The EED and grain yield (GY) were studied as quantitative traits within five locations of the country having various soil and climatic conditions. Using several statistical programs, genotype x environment interaction of two traits was analyzed. The emphasis on data analysis was whether changes of traits due to the conditions were related and that the optimization of the ear emergence date could serve as a breeding tool for increasing grain yield. The date of ear emergence and grain yield are traits that are reliably influenced by growing conditions. The change in the date of emergence is mainly of the linear type, while the grain yield shows linear and nonlinear type changes in the same environmental conditions. It was found that the key roles in the change of characteristics are the conditions of the year, with the relatively weakest impact of the genotype on them. There is a positive relationship between the two traits, although their change depends on environmental factors. Although they change to different degrees and in relation to each other, there is a positive correlation between them. The more favorable the environmental conditions, the weaker the relationship between these two traits and vice versa. Under changing climatic conditions, the change in the relationship between the two traits is a signal of the need to create different varieties by date of ear emergence in order to obtain higher yields in the future.

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Abstract. Information on the relationships between quantitative traits affecting yields is extremely important for winter wheat. For it, the annual genotype*environment interaction is palpable and often masks the influence of individual traits on grain yield. The aim of the study is to determine the traits through the selection of which the grain yield could be significantly increased in the future. The data from three field multifactorial experiments were used (FERT, PGR, ABC), in which a significant influence of various factors (year, point, density, fertilization) on the size and variation of all studied traits was established. In the database thus formed the observed strong variance in the values of the traits is a great prerequisite for the established correlations to be accepted with a high degree of reliability. The mutual influence in the formation of each of the traits is a good basis for their grouping, according to the type of their effect on yield. 1) The characteristics, number of grains per m2 (NGm), grain weight per spike (WGS) and number of productive tillers per m2 (NPT) have a significantly positive effect on grain yield, 2) the weight per 1000 grains (TGW) and number of grains in spike (NGS) are traits that have a direct effect, but it is unstable in manifestation and 3) the traits, as height of stem (HOS), total plant biomass (TBM), and harvest index (HI) do not show a direct effect on grain yields. A significant increase in yield in the breeding of winter wheat can be achieved by increasing the number of grains per unit area (NGm). This is possible while maintaining the achieved level of number of grains in spike (NGS) with a parallel increase of tillering productive ability (NPT). The increase of this trait by selection should be taken into account when reducing the grain size (TGW). This will increase the chance of increasing the number of grains in the spike (NGS), will reduce the weight of the grain per spike (WGS), which in turn will be a prerequisite for optimizing the stability of lodging

The object of the present study was to investigate small and large lymphocytestrafficking in sheep with low and high hematocrit values following shearing,exposure to moderate altitude and transport to low altitude. Twenty out of 101 Ilede France ewes (1-7 years old) were used in the present experiment. All ewes ofthe flock were artificially inseminated in May 2015 following estrussynchronization. The animals were allocated into two groups following threefoldmeasurements of hematocrit in all ewes as follows: I- low hematocrit group (n=10)and II - high hematocrit group (n=10). The ewes were transported to the PetrohanPass (1440 m above sea level) in June 2015 immediately after shearing, conductedat the experimental farm of the Institute of Animal Science, Kostinbrod (500 mabove sea level). Blood samples were collected before shearing, immediately aftershearing, 3 h after shearing, at 14 d following exposure to moderate altitude,immediately after transport to low altitude and following 7d of stay at low altitude.All leukocyte subpopulations were counted microscopically. In the current studywe presented the percentage of lymphocytes only, including small and large(reactive) lymphocytes. High and low hematocrit ewes had different percentage ofsmall lymphocytes when exposed to various acute and chronic stress stimuli. Therewere significant differences in the percentage of large (reactive) lymphocytesbetween low and high hematocrit ewes following blood collection and immediatelyafter shearing. The observed difference in small lymphocyte dynamics among thegroups in response to different stress stimuli was attributed to hematocrit relateddifferences in the time course and magnitude of lymphocyte distribution at earlyand late phases of stress. The results were interpreted to mean that the differencesin lymphocyte trafficking between the two groups of sheep in response to stresswere related to possible difference in the share of aerobic and glycolytic pathwaysfor energy supply.

The kinetics of wheat flour water uptake at 15, 25, 35 and 45 degrees C and different relative humidities from 43.2 to 85.9 was investigated. The water uptake curves obtained were well described by the first-order kinetics equation. A suitable general empirical model was found that includes the effect of temperature and relative humidity.