Because of skeletal muscle is the main contributor to body weight in most fish, it is probable that the species of the fish is limited by the growth of this tissue. Several aspects of both somatic size and skeletal muscle growth was investigated in this research work included a total of 20 brown trout (Salmo truta m. fario Lineus), 20 brook trout (Salvelinus alpinus) and 20 rainbow trout (Oncorynchus mykkis Walbaum), the average weight of 200 grams. Gathered data showed that rainbow trout has a faster increasing white muscles then other two fish species at same body weight. Main peak of diameter white muscles was 31-40 µm (30.55%) and 41-50 µm (22.15%) for rainbow trout. In mean time in the other two fish groups (brown trout and brook trout) was 21-30 µm (40.1% or 39.27%) and 31-40 µm (39.27% or 33.85%) of measured cross sectional areas. Distribution measured cross sectional areas of red muscles laniary goes down from the 71 µm.

In this study we investigated the influence of low dosage X - ray irradiation on the incidence of chromosomal damage and changes in mitotic index (MI) in cultured peripheral lymphocytes of the Bosnian and Herzegovinian mountain horse following in vitro irradiation. X-ray irradiation induced a dose-dependent decrease in MI but only the dose of 0.5 Gy induced a significant decrease (p<0.05) in comparison with the control and other dose groups. The analysis of chromosomal damage revealed a clear dose-dependent increase in the incidence of chromosomal damage per metaphase. Significant differences (p<0.05) were detected by analysis of variance and the LSD test confirmed significant differences between cells that received 0.2 Gy and 0.5 Gy when compared to the control cells and cells that received 0.1 Gy. However, Scheeffes' test assigned significance only to the differences established between the cells that received 0.5 Gy and the other groups of lymphocytes. .

Health control of the mammary gland was conducted comparing results of CMT (California Mastitis Test) and bacteriological findings of milk samples during one year. A total of 3863 secretion samples of mammary glands were collected. There were 85.3% matches for CMT and bacteriological findings. The most frequently isolated causative agents were: staphylococci (52.4%), streptococcus bacteria (23.5%), mixed infections (13.1%), and enterobacteria (10.3%). Secretions disorder and inflammations of mammary gland are most common for the warm period of the year, and very rare for the winter period. With permanent use of these two methods it is possible to obtain satisfactory results in order to get better milk production and health condition of the mammary gland. .