J. Šály’s research while affiliated with University of Veterinary Medicine in Košice and other places

The authors evaluated the effect of diets with different Zn levels on mechanical properties of bones in 60 Ross 308 hybrid broilers, from 2 to 35 days of age, which were randomly divided in 2 groups, with 30 chickens each. The first group (Zn50) was fed a commercial basal diet with no Zn additives (zinc content - 50 mg/kg feed). The second group (Zn100) was fed the basal diet + 50 mg of Zn/kg feed. In this group the dietary Zn level was increased by adding 62.23 mg of zinc oxide (ZnO)/kg feed to starter and grower feeds. In group Zn100 compared to Zn50 the values of blood zinc level were significantly higher on days 7 and 35 (p < 0.01 and p < 0.05). Significant differences in bone zinc content were not detected. On days 7, 21, and 35 the selected mechanical properties of the tibiotarsus were evaluated. The results obtained in the experiment showed differences in biomechanical competence of broiler bones from group Zn50 compared to Zn100. In broilers from group Zn100, there were significantly higher values in the limit of elasticity (Re), bending strength (Rm) and fracture stress (RI) (p < 0.05 to p << 0.01) of chicken bones on day 35. The mean levels (117.80 +/- 19.66, 126.70 +/- 32.56, 114.10 +/- 19.92, respectively) were determined in broiler bones from group Zn100 compared to Zn50 (95.27 +/- 18.71, 100.2 +/- 20.56, 80.93 +/- 35.22, respectively). In group Zn100 were observed significantly increased values of the bone cross-section area (Ar) on day 35 and moment of inertia (I) on days 21 and 35 (p < 0.05). The clinical examination of the locomotory system showed bone deformities of the intertarsal joint in 10% of broilers from group Zn50. Present results suggest that the determination of the weight bearing of the tibial bone evaluated by assessing of mechanical properties of bones is an indicator of the locomotory system disorders and the Zn content in feed has a direct and statistically significant effect on bone strength in broiler chickens.

Probiotic bacteria are used to balance a disturbed intestinal microflora and dysfunctions of the gastrointestinal tract (GIT). They could be an effective alternative to the use of synthetic substances in nutrition and medicine. We investigated the effect of probiotics and potentiated probiotics on the productivity of laying hens. An experiment was carried out on 30 hens of the Hyssex layer hybrid starting from week 30 of laying. The hens were divided into three groups, 10 hens in each (K - control group, L - hens supplemented with probiotics and L + E - hens fed probiotics potentiated with essential oils). No statistically significant differences among the groups were observed in the quality of eggs. Biochemical determination of yolk cholesterol showed an insignificant difference after 25 days of feeding the probiotics. By day 50 of the experiment, yolk cholesterol decreased significantly (P < 0.05) in group L + E and insignificantly in group L of layers. Biochemical examination of blood serum detected an insignificant decrease in the activity of ALT, serum cholesterol and total lipids. Our results allowed us to conclude that probiotics and potentiated probiotics favourably affected the investigated hens and their products.

Skalická M., B. Koréneková, P. Naď, J. Šály: Influence of Chromium and Cadmium addition on Quality of Japanese Quail Eggs. acta Vet. Brno 2008, 77: 503-508. The experiment was conducted to evaluate the effect of chromium (cr) and cadmium (cd) on the quality of Japanese quail eggs. The birds (n = 60) were divided into 3 groups of 20 animals each. Group 1 was the control group. Group 2 was administered 0.12 mg cr/day (cr group) per quail in drinking water, whereas Group 3 was given a combination of 0.12 mg cd and 0.12 mg cr/ day (Cd-Cr group). The distribution of Cd in eggs, the egg mass, and the strength and thickness of shells was determined after after Day 35 and 58 of administration. addition of cr had a positive effect on the weight of eggs. a significant decrease of eggshell strength (p < 0.05) and thickness was found after Day 35 and 58 of the experiment in the Cd-Cr group (3) in comparison to the Cr-only group (2) and the control group (1). The content of Cd was significantly lower (p < 0.05) in eggshells and in the egg yolk from the Cr-only group (2) in comparison to the Cd-Cr group (3) and the control group (1). The data show that addition of cr can improve quality indicators of quail eggs and eliminate the negative effect of cd. Trace elements, Coturnix coturnix japonica, egg weight, strength, eggshell, thickness The study of the role of trace elements in animal nutrition may be useful for meeting the true requirements for optimal performance. environmental stress causes adverse effects on the performance and antioxidant status of poultry.

Probiotic bacteria are used to balance a disturbed intestinal microflora and related dysfunctions of the gastrointestinal tract (GIT). They could be an effective alternative to the use of synthetic substances in nutrition and medicine. This study has investigated the effect of probiotics, prebiotics and potentiated probiotics on the health and production of broiler chickens, ROSS 308 hybrid, 1-42-days-old. The chickens were divided into six groups, 30 chickens in each. Group K served as a control, chickens from group L were supplied probiotics, those from groups O and E received prebiotics, and the diet of chickens from groups L+O and L+E was supplemented with potentiated probiotics. Weight gain, health of the chickens and selected biochemical and hematological blood parameters were observed. This experiment has found that the application of probiotics and prebiotics significantly improved the weight gain of broiler chickens and also affected some biochemical parameters. The study has recorded a significant decrease in concentration of serum cholesterol, as well as the activity of alanine aminotransferase. The individual groups of chickens differed in the content of total lipids, proteins, calcium, phosphorus and the activity of alkaline phosphatase. Results of our experiment indicate that supplementation of the broiler chicken diets with potentiated probiotics has a positive effect on weight gain and the health of chickens.

Chamomile essential oil (Matricaria recutita L.) was applied to 16 laying hens - hybrid Hisex Braun. In this model experiment, hens of 15 weeks in age were divided into 2 groups including 8 hens in each - a control group (CG) and an experimental group (EG). They were housed in battery cages system having water intake ad libitum. Hens in EG were fed feed mixture HYD 6 and HYD 10 enriched with chamomile essential oil (0.1%) daily for a period of 8 weeks. Weight of eggs was checked daily during the whole experiment. Significant difference (p<0.001) in weight of eggs comparing CG and EG was found from week 4 to 8 of the experiment. Although only a small number of animals was involved in this model experiment, application of chamomile essential oil indicated probability of a positive influence (increase) on the weight of eggs of laying hens. Experiments using higher amounts of hens will be processed to confirm this positive achievement.

We report the effects of cadmium (Cd) and zinc (Zn) on the quality of Japanese quail's eggs. For this study, 60 birds were divided into 3 groups of 20 subjects each. The animals in group 1 received 4 mg Zn/d, whereas those in group 2 were given a combination of 4 mg Zn/d and 0.12 mg Cd/d. The quails in group 3 were not given any supplements, acting as controls. The distribution of Cd and Zn in the eggs, the eggs' mass, and the strength and thickness of the shells were determined after 35 and 58 d of supplementation. Zinc showed a positive effect on the mass of eggs and accumulated mainly in the egg white. The content of Cd was significantly lower in the egg yolk of birds in group 1 (p<0.001), whereas those in group 2 had decreased eggshell thickness and strength in comparison to groups 1 and 3 (p<0.001). These results suggest that the adverse effects of Cd on the quality parameters of eggs from commercially important bird species can be, at least in part, counteracted by Zn supplementation.

The study presents a median lethal dose (LD50) of sodium salinomycin in Slovak anticoccidial preparation Synvertas and in German anticoccidial preparation Sacox 120 for 4-week-old chickens. On the basis of acute toxicity of sodium salinomycin, defined in the preliminary experiment, the LD50 was determined in a group of 40 Ross I meat hybrid chickens of both sexes, weighing 1320-1820 g. Clinical symptoms of poisoning and patho-morphological changes in dead chickens were observed as well. LD 50 of sodium salinomycin in the respective preparations was calculated using double-dose interpolation method according to Roth (1962) on the basis of 24 h mortality. The LD50 for sodium salinomycin in Synvertas was 107.5 mg.kg-1 b. w. (1075 mg of preparation) and that in Sacox 100.0 mg.kg-1 b.w. (833.3 mg of preparation). From the clinical signs of intoxication after lethal doses of 100 and 120 mg of sodium salinomycin per kg-1 b.w. (1000 and 1200 mg of Synvertas preparation and 833.3 mg and 1000 mg of Sacox preparation), the following predominated: locomotor ataxia, semiprone or sternal lying position with neck stretched forward and legs stretched backwards, dyspnoea, cyanosis, serious central nervous system inhibition, loss of vocal and tactile responses. Death occurred within 17 h and was accompanied by mild myoclonus symptoms with backward stretched limbs. Hyperaemia of the liver, pancreas, spleen and kidneys, anaemia of GIT mucosa, diffuse acute bronchopneumonia (lung oedema in one chicken), slight anaemia of thoracic musculature and slight banding of thigh and thoracic musculature were observed in the majority of dead chickens. The toxic effect of sodium salinomycin started to manifest itselt after a sublethal dose of 20 mg.kg-1 b.w. (200 mg of Synvertas preparation and 166.6 mg.kg -1 b.w. Sacox preparation). Poisoning symptoms were very weak and disappeared after 15 h.

The effect of lead on productivity and health condition of Dominant hybrid layers in the 9th month of laying was observed for 45 d. Layers of the control group were fed complete mixed feed for layers. The 1 st experimental group received feed supplemented with lead at a level of 1000 mg.kg -1 mixed feed. The 2nd experimental group, in addition to this dose of lead received vitaminous and mineral mixture consisting of calcium carbonate, sodium hydrocarbonate, Foeniculi fructus, zinc sulphate, mangane-se sulphate, and vitamin C at 3% concentration. Lead addition caused a decrease in the egg weight, strength and thickness of egg shell, content of calcium, iron and vitamin E in blood as well as a decrease in solidity of the tibiae of the hens. The activity of alkaline phosphatase and alanine aminotransferase, content of phosphorus and copper and leukocyte count in blood were enhanced by lead addition. This adverse effect of lead on metabolism of calcium and egg shell quality was confined by supplementation with the mentioned above vitaminous and mineral mixture. Lead addition reduced also the number of erythrocytes and content of haemoglobin. In one-day-old chicks there were significant changes in alanine aminotransferase activity. Lead at a dose of 1000 mg.kg -1 feed caused neither clinical nor pathological changes in layers.

 The effect of cadmium and vitamin D3 on the solidity of eggshells was observed. Laying hens were divided into 7 groups with 10 animals per group. In the experimental groups 1, 2, and 3, we administered daily 0.3; 10.0, and 15.0 mg CdCl2 kg–1 body weight, respectively; in experimental groups 4, 5, and 6 were administered the same CdCl2 concentrations as above supplemented with a preventive dose of vitamin D3 Group 7 was the control group. In groups 1, 2, and 3, the mean values of solidity were 29.50; 27.58, and 27.34 N/cm2. In the control group, the mean value was 34.05 N/cm2. In the experimental groups 4, 5, and 6, supplemented with vitamin D3 and cadmium, the values were significantly higher: 34.26, 30.59, and 29.48 N/cm2, respectively It is obvious that the interaction of vitamin D3 with Cd reduced an adverse effect of cadmium.

The work presents an initial information about degree of toxicological risk for chickens treated with sodium salinomycin in the Slovak anticoccidial (Synvertas plv. ad us. vet., Biotika, Slovenská L'upcǎ, Slovak Republic), under conditions of acute intoxication. Median lethal dose (LD50) of sodium salinomycin in Synvertas plv. ad us. vet. preparation (Biotika) has been determined in 2 and 4-week-old chickens, both sexes, meat type Ross breed. Clinical symptoms of poisoning and patho-morphological changes in dead chickens have been observed as well. Development of clinical symptomatology of poisoning and decrease in intoxication symptoms in 4-weeks-old chickens has been observed even after a single administration of sodium salinomycin in sublethal doses : 20, 30, 40, 50, and 70 mg.kg -1 of body weight (b. w.). LD50 of sodium salinomycin in the objective preparation was calculated on double dose by the interpolation method according to Roth et al. (21) on mortality within 24 h. LD50 value of sodium salinomycin in Synvertas preparation was determined at 102 mg.kg -1 of b. w. (1020 mg of preparation) in 2-week-old chickens and at 106 mg.kg -1of b. w. (1060 mg of preparation) in 4-week-old ones. From clinical signs of intoxication after lethal doses of 100 and 120 mg of sodium salinomycin per kg -1 of b.w. (1000 and 1200 mg of preparation), the following signs were in the foreground: ataxia, lying on the side or in sternal position with forward stretched neck and legs stretched backward, dyspnoea, cyanosis, sharp CNS inhibition, loss of acoustic and touch reactions. Death occured within 12 h and was accompanied by mild myoclonus symptoms (3-4) with backward stretched limbs. Hyperaemia of the liver, pancreas, spleen and kidneys, anaemia of GIT mucosa, diffuse acute bronchopneumonia, in one chicken lung oedema, slight anaemia of thoracic musculature, slight banding of thigh and thoracic musculature were recorded in most dead chickens. The toxic effect of sodium salinomycin started to manifest itself in 4-week-old chickens after sublethal dose of 20 mg.kg-1 of b. w. (200 mg of preparation). Poisoning symptoms were very weak and disappeared after 15 h.