It is well known that target removal or distal axotomy in adult animals results in no detectable loss of motoneurons in the spinal cord. By performing axotomy in the seventh cervical (C7) spinal nerve at different distances from the spinal cord (0, 2, 4, 8 mm respectively), this study examines the effects of the remaining axons on motoneuron survival as well as NOS expression. Results of the present study show that axotomy in adult peripheral nerve can induce significant spinal motoneuron death if axotomy is performed close enough to the spinal cord. The closer the axotomy to the spinal cord, the higher the rate of motoneuron loss was observed. The most significant motoneuron loss was found in animals with axotomy at 0 mm to the cord, which was coincident with the highest percent of NOS-positive motoneurons. The rate of survival of motoneurons increases and the percent of NOS-positive motoneurons decreases when the distance of the axotomy to the cord increases from 0 to 4 mm. No significant motoneuron loss nor NOS-positive motoneurons were observed when axotomy was performed at 4 mm and distally. These results indicate that the survival of spinal motoneurons in adult rat following axotomy is largely dependent on the length of the remaining axons. The longer the remaining axon, the better for motoneuron survival. The minimal length of axon for motoneuron survival in adult rat seems to be at least 4 mm.

Merinolandschaf sheep breed was used to estimate relationship between the next traits: Body weight of adult ewes (BW), Height to withers (HW), Body length (BL), Girth of Chest (GC), Rump Width (RW), Body weight of lambs at birth (BWB), Body weight of lambs at weaning (BWW). The collected data were from 750 sheep and their lambs during the period of three year. Estimates of means and standard errors for linear body measures and body weight of adult ewes and lambs, were obtained using the software program SPSS (2006). To estimate genetic and phenotypic correlations of observed traits, the ASREML program was used. Research has shown that genetic correlations between BW and all body measures of dams, ranging from 0.728 (BW-GC) to 0.976 (BW-HW). Genetic correlation between body measures of dams have also been positive and ranged in the interval from 0.873 (HW-GC) to 0.999 (BL-GC). Values for phenotypic correlations were lower compared with the genetic and the range varied from 0.183 (RW-BWB) to 0.421 (GC-BWW). The weaker phenotype correlations can be interpreted as play of more complex genetic and residual factors.

Bacterial abundance in the water used for drinking by humans and animals is a parameter that is closely linked to their health. Therefore, application of a method of detection of bacterial count which will indicate the real status of this parameter, as authentically as possible, is necessary. The bacterial load of water in certain stages of water supply using direct and cultivation methods was investigated. In the cultivation method, the water samples were inoculated on PCA and on R2A medium, and incubated for 7 days at 37 °C and at room temperature. Direct method included filtration of samples stained with acridine orange and counting of bacteria on the filters under the epifluorescence microscope. Cultivation and direct methods showed the lowest bacterial count in the tank of Bagdala II, 0 cfu/ml and 611 bacteria/ml, respectively, and maximum abundance in raw water, 157 cfu/ml and 1,378,698 bacteria/ml, respectively. Statistical analysis showed that significantly higher count of bacteria was recorded on R2A medium compared to PCA, and at room temperature than at 37 °C. By index TBC/AMB, the native raw water was classified as more polluted water when applying the results obtained at room temperature compared to the results obtained at 37 °C. The most realistic bacteriological status of all water types was obtained using the direct method of quantification of bacteria. However, for routine monitoring of water in water supply system, as well as for the examination of bacterial regrowth in the distribution network, it is the best to apply the cultivation method which involves inoculation of samples on R2A medium and incubation at room temperature.

Estrus synchronization methods was use to control the reproductive traits of sheep, as well as bringing more females at the same stage of estrus and ovulation. According to the points mentioned above, the aim of the present study was to investigate and compare mating method and influence of fixed factors on birth and weaning weight of lambs. Statistical analysis showed that exist difference in the body weights between genotypes of lambs. In the first group, the difference in weight of lambs at birth, regardless of mating method was not significant (P> 0.05), while in the second group, the difference was slightly significant (P <0.05). As for the birth type, sex and within the same genotype, there was a statistical significance (P <0.05) between singles obtained naturally, between the triplets obtained naturally and between triplets received hormonal method. All the differences between body weight at 30 days (mating method, sex and birth type under the same genotype) were statistically significant (P <0.05).The determined differences in the body weights at 60 days (sex, mating method and type of birth under the same genotype) were statistically significant (P <0.05). The results showed that the differences (mating method, sex and type of birth under the same genotype) were statistically significant (P <0.05), except in between body weight at 90 days in twins among two genotypes obtained by natural method, which were not statistically significant (P> 0.05). [Projekat Ministarstva nauke Republike Srbije, br. TR31001 i br. TR31053]