Dragan Zikic

Neuroprotective effects of hypothermia and erythropoietin after perinatal asphyxia in newborn rats.

Abstract Objective: Evaluation of neuroprotective effects of hypothermia, erythropoietin and their simultaneous use after perinatal asphyxia in newborn rats. Method: Histerectomy was performed to Wistar female rats on the last day of gestation. Perinatal asphyxia was induced by submersion of uterus containing pups in saline for 15 min. After resuscitation, pups were randomized into 4 groups, 15 animals in each: G1 – asphyxia; G2 – asphyxia + hypothermia (rectal temperature 33 °C for 1 h); G3 – asphyxia + erythropoietin (Darbepoetin-α 2.5 μg, intraperitoneally) and G4 – asphyxia + erythropoietin + hypothermia. Pups were sacrificed on 7th day of life and histopathological analysis of hippocampus was performed. Results: Measure of damage to dorsal, ventral and entire hippocampus was significantly lower in groups G2, G3 and G4 than in group G1 (p ∼ 0.00; respectively). Measure of damage to hippocampus in group G4 was significantly lower than in group G2 (p = 0.029). Conclusions: This study demonstrates that simultaneous use of hypothermia and erythropoietin has more expressed neuroprotective effects than sole use of hypothermia after perinatal asphyxia in newborn rats.

THE INFLUENCE OF LONG TERM SOUND STRESS ON HISTOLOGICAL STRUCTURE OF BROILER'S ADRENAL GLANDS

The aim of this paper is to examine the effect of different sound stress duration on adrenal gland of broiler chickens of different age. The experiments were conducted on 90 HYBRO broiler chickens, divided into nine groups (each group consisting of 10 birds) by different age and lenght of sound stress duration. The chickens were exposed to sound stress in sound attenuated building using a fire alarm bell (95 dB) for stress sessions lasted 120 min every day. The histological structure of adrenal gland was analyzed by light microscopy. The results indicate that adrenal gland is sensitive on this kind of stress and sound as stressor could introduce organism in stress reaction. Adrenal glands of broilers exposed to sound stress characterized by marked hyperemia, hypertrophy of interrenal cells, smaller affinity for staining of chromaffin cells compared with control groups. According to our results, degree of histological changes of adrenal gland under the influence of sound stress depends on the length of exposure and age of chickens.

Electromagnetic Field Effects on the Morphology of Rat Thyroid Gland

The thyroid gland, whose hormones are involved in a broad range of functions is one of the most sensitive organs to ionizing radiation, but the effects of non-ionizing radiation such as an electromagnetic field (EMF) on this gland has been suggested1,2 even if not supported with sufficient data.

Use extruded rapeseed meal in the feed of broiler chickens

The aim of the study was to investigate the effects of extruded rapeseed meal in the diet on broiler performance. Chickens of Ross 398 hybrid were used in the trial. The trial lasted 42 days. Rape seed meal was extruded prior to use and included in the diet at the level of 4% (group 2) and 8% (group 3), and control group of chickens (group 1) fed the standard mixture based on corn, soybean meal and soybean grits. Chickens of the control group scored the highest ranking and realized the final body mass of 2212 g, whereas the chickens of group 2 had the final body mass of 2191 g, and chickens of group 3 with final body mass of 2148 g were the worst. Falling behind of the trial groups in relation to the control group in regard to the body mass at the end of the trial was by 0,91% group 2 and by 2,89% for group 3. Feed conversion ratio was the best in group 2, followed by control group, and the worst was the group 3 (1,882; 1,866; 1,894, respectively). The lowest mortality rate was realized by chickens of the control group, followed by group 2 and group 3 (4,00%; 4,33%; 5,33%, respectively). The control group of chickens had the best production index value, followed by group 2 and the lowest value of the production index was established for chickens of group 3 (270,95; 265,18; 255,63, respectively). It can be observed that the depression in trial groups was within the limits of toleration, which indicates that extruded rapeseed meal can be included in the diets for fattening chickens in ratio up to 10%.

Morphodynamics of embryonic development of skeletal musculature of broiler and layer chickens.

Eggs of broiler (Ross 308) and layer (Hy-Line Brown) chicken hybrids were incubated and tissue samples from the leg muscle (m. biceps femoris) and breast muscle (m. pectoralis profundus) were taken on embryonic days 9, 12, 15, 18 and 20, as well as on the first day post hatching. Histological preparations were made from the samples and the diameter of muscle cells, the volume density of connective tissue of muscles, and the nucleocytoplasmic ratio of muscle cells were recorded. Comparison of the diameter of muscle cells of leg muscle and the breast muscle between broiler and layer chicken during the period of late incubation and day 1 post hatching showed the diameter of the examined muscle cells was greater in layers, while the nucleocytoplasmic ratio of muscle cells was higher in broilers. No differences were established between these two strains in the volume density of connective tissue in both muscles examined. Such results are explained by the prolonged proliferation of myoblasts and delayed differentiation of muscle cells in broilers, which leads to a greater development of the skeletal musculature during the postnatal period. These processes in the embryonic period of development are the cause of differences in the morphodynamics of embryonic development of the skeletal musculature between broilers and layers presented in this paper.

Electromagnetic Field Effects on the Morphometrical Characteristics of Rat Adrenal Glands

Effect of the magnetic field on the biological mechanisms is still poorly known. It was considered for a long time that the effect of magnetic field was identical to the effects produced by high and low temperatures, ultraviolet rays and noise (Nakagawa, 1984). Long-term exposure to LF-EMF induced morphological and morphometrical changes on thyroid gland (Matavulj et al, 1996) and adrenal glands (Uscebrka et al, 1996). Magnetic fields have been shown to influence the release and levels of a number of neurotransmitters (Kavaliers and Ossenkopp, 1987; Zecca et al, 1997) and opioid molecules (Prato and Kavaliers, 1997), with these actions being proposed to involve alterations in neuronal calcium levels and fluxes (and possibly other divalent ions) and in the stability of calcium binding to neuronal membranes (Blackman et al., 1985, Kavaliers and Ossenkopp, 1986).

Effect of different litter treatments on production performance of broiler chickens.

In modern poultry production, foot pad dermatitis (FPD) represents one of the main problems on broiler chicken legs with significant affect on animal welfare and performance. This problem is not solved by the using of straw as litter. Different treatments of straw are needed to eliminate the adverse effects of this material as litter. The most widely used method to improve the quality of litter is chopping straw and application of microbial products on that. These procedures can decrease the moisture in the litter and reduce the population of microorganisms whose activity produces ammonia, and hence improving environmental conditions in facilities. The experiment involved four treatments with four replications with a total of 300 broilers per treatment. The treatment I was unchopped straw, treatment II was chopped straw, treatment III unchopped straw with the addition of microbial products, and treatment IV was chopped straw with the addition of microbial preparation. Duration of trial was 42 days. During the experiment, the following production parameters were measured: body weight per week of the experiment, feed conversion ratio, mortality and FPD. Results of the trial point out that the best production results were in treatment IV with an average final body weight of 2.456g and feed conversion ratio of 1.71. [Projekat Ministarstva nauke Republike Srbije, br. TR 31033]

Skeletal muscle characteristics of broiler chickens under modified incubation factors

Four groups of broiler chicken hybrid (Ross 308) eggs were incubated under different temperature and light conditions to assess the effects of both variables on musculature development. During the incubation, the first group was the control and the eggs were incubated at a temperature of 37.8 °C without light, the second group was exposed to increased temperature, while the third group was exposed to monochromatic green light. The fourth group of eggs was incubated under simultaneously changed temperature (according to the regime of the second group) and light (according to the regime of the third group) conditions. Tissue samples from the breast muscle (M. pectoralis superficialis) were taken on embryonic days 9, 12, 15, 19 and 20, as well as on days 1, 3, 7, 14, 21 and 42 after hatching. Histological preparations were used to assess muscle cell diameter, connective tissue volume density, and the nucleocytoplasmic ratio of muscle cells. Our findings indicate that thermal and light manipulations during incubation increase diameter and decrease nucleocytoplasmic ratio in postnatal skeletal muscle cells. No differences were found among groups with regard to connective tissue volume density. These results can be explained by the influence of thermal and light manipulations during incubation on prolonged myoblast proliferation, as well as on the greater postnatal development of skeletal muscle cells.

İlave Koenzim Q10 ile Beslenerek Derin Pektoral Myopati Oluşturulan Etlik Piliçlerde Miyopatinin Devrelerinin Belirlenmesi

The aim of this study was to examine the structural characteristics and incidence of different stages of deep pectoral myopathy (DPM) that was induced in broilers fed a coenzyme Q10 (CoQ10) supplemented diet. A total of 288 1-day-old chicks (Cobb 500) were equally divided among 8 pens (pens 1 to 8). The diet was the same for all chicks until day 35 post-hatching. Subsequently, broilers in pens 5 to 8 were fed the 20 mg of CoQ10/kg finisher diet until the end of the experiment (day 42 post-hatching). To induce DPM, 5 male birds from each of the pens 1 to 8 were subjected to encouraged wing flapping (EWF) at the end of their 37th day. At the end of the trial, the incidence of DPM stages in broilers was determined and an analysis of the histological parameters of deep pectoral muscles was performed. Results showed that, in the groups subjected to EWF, broilers with the CoQ10 supplement had a lower average DPM stage and volume density of necrotic muscle cells, as well as a higher volume density of non-necrotic muscle cells. These results can be related to the antioxidant properties of CoQ10, which, in chickens subjected to EWF, reduced the effects of DPM on cell necrosis and muscle tissue damage.

Effect of Litter on Development and Severity of Foot-Pad Dermatitis and Behavior of Broiler Chickens

ABSTRACT This study was conducted to evaluate the impact of litter type and litter treatment with enzymatic-bacterial production incidence and severity of footpad dermatitis and consequently on behavior of broiler chickens. A total of 1,200 one day-old Ross 308 broilers were randomly allocated to 4 treatments with 4 replicates in 2 x 2 factorial design. The first factor was the physical form of the straw (chopped on approximately 2 cm or un-chopped) and the second factor was addition of enzymatic-bacterial product applied directly on the straw. Each replicate consisted of 75 as-hatched birds per pen. Occurrence and severity of the footpad dermatitis and histological evaluation of the scores was done at the end of the trial (42 days of age). During the trial, at 3 and 6 weeks of age, broiler behavior was observed by Scan Sampling Method. The results showed that chopped straw significantly lowered the incidence of footpad dermatitis. Chopped straw in combination with enzymatic-bacterial product showed the lowest footpad dermatitis score in broilers. Histological procedures confirmed the macroscopic evaluation of the footpad dermatitis severity. The chopped straw had a significant effect on some behavioral patterns of broiler chickens. Differences were observed for dust bathing and scratching. Correlation between footpad dermatitis and birds locomotor activity was not confirmed.