Abstract This study aimed to investigate the effects of dietary supplementation with modified-hen-egg-yolk on plasma lipids and lipoprotein profiles in rats. During the four-week-experiment, 64 Wistar rats were divided into four groups of 16 (eight of both sexes), and fed commercial rat food (group C); food containing 70% commercial rat mixture and 30% freshly cooked egg yolk originating from laying hen eggs fed with 3% fish oil (group F); 3% palm olein (group P), or 3% lard (group L). The cooked egg yolk in the rat diet affected the concentrations of plasma total and LDL-cholesterol in males of the P and L groups. Cholesterol and total fat in the diet did not have a hypercholesterolemic effect on their own, but when in combination with fatty acid composition, they could contribute to an increase in plasma total and LDL cholesterol concentrations in rats. HDL-cholesterol was the most resilient plasma lipoprotein of rats to dietary treatments in our experiment. Compared to the control group, the addition of hen egg yolk to the rat diet regardless of its quality, adversely affected the values of HDL-C/TC and HDL-C/LDL-C in both males and females.

The study was aimed at determining plasma concentrations of albumin and total protein (TP) in 480 dairy Holstein-Friesian breed cows on different localities in Bosnia and Herzegovina and in different seasons (diet conditions). The samples were taken from the cows in lactation, postpartum period within 15 days from calving, and the dry period. Seasonal variations affected both investigated parameters. Differences among localities were determined during summer for TP concentrations and during winter for albumin concentrations. Differences were considered statistically significant at p<0,05. Results show significant influence of the diet conditions on plasma concentrations of examined parameters so the conclusion is their constant monitoring during the production period is required. Key words: dairy cows, albumin, total protein

The paper presents the morphometric characteristics of red blood cells of endemic fish species of Bosnia and Herzegovina, Telestes metohiensis (Steindachner, 1901) inhabiting the Vrijeka river in the Dabar field. A total of 30 fish were sampled during August, 2010. Morphological measurements included the following parameters: axes of the red blood cells and nuclei, the surface of the red blood cells and nuclei and the thickness of the red blood cells. Morphometric characteristics of the erythrocyte maturation stages (acidophilic and polychromatic erythroblasts) were also studied as well as their proportion in the peripheral blood. 100 mature forms were measured for each individual. The propotion of the immature forms was expressed per 1000 erythrocytes. Results showed that dimensions of the erythrocytes differed in systematic categories as well as fish types. Dimensions of mature erythrocytes and their maturation stages of the same species differed in shape and size of the nuclei. Proportion of the erythrocyte maturation stages was very low in comparison with the mature erythrocytes, indicating the optimal environmental conditions for the studied species. Key words: morphometric characteristics, erythrocytes, Telestes metohiensis, proportion of immature stages

The aim of this study was to research the impact of a diet supplemented with egg yolks of modified content, having in mind the type of fat added to the laying hens diet, on the brain lipids and their fatty acid composition in rats. During four weeks of the experiment, 64 Wistar rats, divided into four groups of 16 animals each (eight animals of both sexes), were fed the commercial rat feed (group C), or the feed that contained 70% of the commercial rat feed and 30% of freshly boiled yolks from the eggs originating from laying hens fed with 3% fish oil (group F), 3% palm olein (group P) or 3% lard (group L). Concentration and content of total lipids and total cholesterol, as well as the fatty-acid composition of the total brain lipids were determined in the lipid extracts of the rats brains. Under unfavourable conditions, which in our case could be high dietary intake of the total fat due to egg yolk addition, the amount of total fat in the brain tissue or the mass of the organ itself can be changed. Applied dietary treatments could also influence the level of de novo synthesis of total cholesterol in the rat brain. High dietary fat intake, as well as the fat quality regarding its fatty acid composition, appear to be able to significantly influence the fatty acid profile of the total brain lipids in adult rats, whereas the level and quality of the changes also depend on sex.

The aim of this study was to examine the effects of diets supplemented with egg yolks of modified composition on the fatty-acid composition and lipid content in rat’s liver. During four weeks of the experiment 64 Wistar rats were divided into four groups of 16 individuals each (eight individuals of both sexes) and fed a commercial feed mixture for rats (group C) or diet containing 70% commercial mixture for rats and 30% freshly cooked egg yolks from laying hens fed diets with 3% fish oil (group F), 3% palm olein (group P) or 3% lard (group L). Dietary supplementation with egg yolks significantly increased the hepatic cholesterol pool in rats, regardless of the type of fat in the diet of laying hens from which the eggs originated. The content of α-linolenic acid in the liver of male rats in group P was 4-6 times higher compared to males in the other groups. Liver lipids and their fatty-acid composition differ by both, sex and dietary modified egg yolk composition in rats.

The research was conducted on 240 clinically healthy Holstein-Friesian cows in various stages of the reproductive cycle (lactation, dry period, and up to 15 days from calving). Sampling was taken during the summer and winter periods. Concentrations of calcium, phosphorus and magnesium in blood plasma were determined by using the appropriate method with the “Beckmann DU-64 UV/VIS” spectrophotometer. Significant differences were determined in the values of concentrations of the examined minerals during various stages of the reproductive cycle but in dependence on the season of sample taking.

The study was aimed at determining levels of alanin aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in the plasma of 229 dairy Holstein-Friesian breed cows in different stages of the re¬production cycle and regarding the seasonal changes (diet conditions). Cows were divided into the groups: lactation (Group A), postpartal period within 15 days from calving (Group B) and dry period (Group C). Seasonal variations affected AST activity within Groups A and B, while Group C showed no seasonal influence. Differences between Groups A and B were determined during winter, as well as among Groups A and C during the same season. The highest activity of ALT was measured in cows from Group A during the winter season. ALP activity showed no statistical difference among groups, though statistical significance was noted within seasonal changes. The activity of LDH showed no statistical significance within Group C with regard to the seasonal changes. Statistically significant difference was found between cows of Group A and C during the winter season. Differences were considered statistically significant when p<0,05. Research results showed a significant influence of milk production and dry period on the activities of measured enzymes in the blood plasma so we can conclude that there is a need for constant monitoring of the described parameters during the production period. Key words: dairy cows, ALT, AST, ALT, LDH

Pramenka je ovca kombiniranih svojstava, skromna u ishrani, vrlo otporna i dobro prilago ena našim uvjetima, ali slabih produktivnih osobina jer se uzgaja u brdsko-planinskim uvjetima, nepovoljnim za intenzivniju proizvodnju sto ne hrane, zbog ega je ishrana veoma esto kvantitativno i kvalitativno nedostatna. Na pravilnost ishrane ukazuje razina njihove proizvodnje, ali i njihov metaboli ki status koji se prosu uje odre ivanjem biokemijskih parametara krvi. Biokemijski parametri krvi mogu ukazati na energetsku, proteinsku i mineralnu opskrbu organizma, a istovremeno i na zdravstveni status životinje. Stoga smo proveli ispitivanje širokog spektra biokemijskih parametara u krvi ovaca s dva lokaliteta, op ine Livno i Travnik, u ljetnom razdoblju kada su životinje bile na ispaši karakteristi nog botani kog sastava navedenih podru ja, a sve s ciljem usporedbe sa standardnim vrijednostima parametara za ovce, ali i me usobnih podataka s dva razli ita podru ja. Krv je uzorkovana iz v. jugularis i u serumu su odre ivani sljede i biokemijski parametri: glukoza, Mg, P, Ca, ukupni proteini, LDH, GGT, AST, ALT, ALKP, kolesterol, trigliceridi, urea i albumini. Važnost istraživanja je u injenici da se prou avanjem metabili kog statusa unapre uju saznanja o interakciji lokalnog uzgoja i metabolizma ovce u funkciji održivosti autohtonih pasmina.

The influence of dietary palm olein, in comparison to fish oil and lard, on lipid levels in egg yolk and blood plasma, the fatty acid composition of egg yolk, and various production parameters were studied. Brown Lohman laying hens (n=45) were randomly assigned into three groups of 15 birds, and treated with experimental diets with either 3% palm olein (PO), fish oil (FO) or lard (L) for 6 weeks. At the end of the experiment, feed consumption was significantly lower for hens fed the PO diet, except week 6 of the experiment. The concentration of plasma triglycerides was increased by all experimental diets, whereas there were no significant increases of plasma total lipid and total cholesterol concentrations only in the PO group. For yolk lipids a decrease in triglycerides in the FO and L groups was observed, while total cholesterol and total lipid were significantly decreased in the PO group. Feeding with the PO diet resulted in the lowest concentrations of palmitic, stearic and linoleic acid, as well as in the highest concentration of monounsaturated oleic acid in the yolk total lipid. It was concluded that the composition of yolk lipids did not closely match the concentrations of lipids observed in experimental diets or plasma. Based on the current work it seems that the PO diet modulates egg yolk lipid content best.

The aim of this study was to investigate the possibility to modification the total lipid and cholesterol level, as well as fatty acid composition of egg yolks, by supplementing diets of laying hens with different fats. The trial was conducted in two six week experiments. Experiment I was conducted on 180 Isa Brown hens assigned to two age categories: 36 months - old (O), and 27 weeks of age - young (Y) hens. Both ago categories were divided into three groups: control groups fed a diet I with no supplemented fat (OC and YC) experimental groups fed a diet II supplemented with 3.2% of palm oil (OP and YP) and experimental groups fed a diet III supplemented with 2.5% of lard (OL and YL). In Experiment II 45 Lohman Brown hens of 56 weeks of age were randomly assigned into three groups of 15 birds each and were fed with three experimental diets supplemented with either 3% fish oil (group FO), 3% palm olein (group PO) or with 3% lard (group L). The results of our trial support the thesis of constant cholesterol content in egg yolk, that was accepted by the majority of researchers, although it was possible to affect the levels only in some conditions, as for example by the age of hens in Experiment I or by feeding Lohman Brown hens with 3% of supplemented lard in Experiment II. However, the experiment proved the possibility of altering egg yolk fatty acid composition, this being a trend in actual investigations of egg yolk cholesterogenic modification.