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.

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. .