Abstract. The studies were carried on 30 random 8-week old Swiss male mice. The mice of I group received peritoneally 100 μg/g b.w. of reduced glutathione (GSH) in 250 μl 0.9% NaCl , II group 200 μg/ g of GSH in 250 μl 0.9% NaCl and mice of III control group received 250 μl of 0.9 % NaCl. In the lysosomal fraction of the liver, kidney and the skeletal muscle the activity of nine lysosomal enzymes were estimated. GSH injections caused in the liver a statistically confirmed increase of activity of estimated hydrolases, only the activity LL decreased significantly and NAGL did not change. After injection of both GSH doses increased significantly the activity LAP, Cat. D and L, AP, BGAL, BGLU and NAGL in the kidney. After injection 200 μg/g of GSH increased significantly activity AAP but an activity EL and LL decreased. In the skeletal muscle was observed a statistically confirmed increase of AP, LL, BGAL and NAGL activity, only the BGLU and Cat. D and L (after 100 μg/g dose) activity decreased.

Summary The studies were carried out on 48 8‐week‐old Swiss male mice. The animals were divided into those selected for body weight gain (experimental) and an unselected (control) group. Twelve selected and unselected mice received a high protein diet (40%) during 14 days while the remaining 12 selected and 12 controls received a low protein feed (10%). In the lysosomal fraction of the liver and kidney, the activities of alanyl aminopeptidase, leucyl‐aminopeptidase, cathepsin D, L, acid phosphatase, lysosomal esterase, lysosomal lipase, beta‐galactosidase, beta‐glucosidase, beta‐glucuronidase, N‐acetyl‐beta‐glucosaminidase were measured. The results obtained suggest that the different dietary protein levels (10 and 40%) and selection changed the activity of lysosomal enzymes studied in the liver and kidney of experimental mice.

Abstract. The study included 177 Polish Friesian cattle with an over 75% Holstein proportion – 117 heifers and 60 young bulls 250 days old. The animals were progeny of 27 AI Holstein sires. All individuals were housed in a tie stall and fed ad libitum silage, hay and concentrate until the 7th month of age. From the 7th to the 8th month of age the animals of both sexes received an ad libitum full concentrate diet. Almost in the all cases the activities of lysosomal enzymes were higher in heifers (except NAG, BGAL, AP). The 48 h starvation did not influence AAP, LAP, AP, LL, BGLU activity in bulls and BGRD, BGAL, BGLU and NAG in heifers.

SummaryWhite New Zealand male rabbits (n = 12) were fed by high-cholesterol diet for 7 weeks. The activity of some lysosomal enzymes in blood plasma and in the liver was determined. The cholesterol-enriched diet resulted a significant of AP, LL, BGAL and BGLU activity up increase in the blood plasma to 131%, 186%, 308% and 184% as compared with those in control group of animals (n = 10). In the liver a significant increase of EL activity to 189%, NAG to 172% and BGAL to 196% was observed. The activity of LAP and LL decreased significantly to 76% and 60% of the control level, respectively.Key Words: lysosomal enzymes, cholesterol, rabbits Zusammenfassung Titel der Arbeit: Einfluss der mit Cholesterin ergänzten Futterration auf die Aktivität von einigen lysosomalen Enzymen in der Kaninchenleber Die männlichen Kaninchen der Rasse Weisse Neuseeländer wurden 7 Wochen lang mit einer Cholesterinfutterration gefüttert. Die Aktivität von folgenden lysosomalen Enzymen im Blutplasma und in der Leber wurde bestimmt: säure Phosphatase (AP), Alanin-Aminopeptidase (AAP), Leuzin-Aminopeptidase (LAP),, lysosomale Lipase (LL) und lysosomale Esterase (EL). Die Fütterung mit Cholesterin bewirkte eine signifikante Erhöhung der Aktivität von AP, LL, BGAL und BGLU im Blutspiegel und eine Abnahme der Aktivität von EL und NAG im Vergleich mit der Kontrolltiergruppe. In der Leber der Kaninchen, die mit Cholesterin-Futter gefüttert wurden, konnte eine Abnahme der Aktivitat von LAP und LL beobachtet werden.

Abstract. The aim of this study was to estimate an influence of supplementation of exogenous N-acetylcysteine (NAC) on the somatic cell count (SCC, quantified as cells per ml) and chemical composition of goat milk. The study was carried out on 15 goats, in the last part of lactation (220-250 days). The animals were divided into 3 groups according to SCC in their milk: 1st – up to 2×106, 2nd – from 2 to 4×106 and 3rd – above 4×106. The animals were clinically healthy. They were given NAC in the amount of 12 mg/ kg of live body weight per os for 7 days, once a day, during evening milking. Milk yield, as well as fat, protein and lactose contents and SCC were studied three times: 1st – just before starting the experiment, 2nd – after 7 days of NAC application and 3rd – a week after the end of NAC application. The analysis of variance with General Linear Model (GLM) procedure of SAS® package was used. There was observed the significant decrease of SCC after one-week supplementation of NAC and stagnation of SCC after next week in all three groups. The changes of chemical composition of milk were not significant. The significant decrease of SCC may indicate improvement of health of mammary gland. The oxidation processes might be decreased and probably the increase of immune defence of organism took place. One can suggest that the supplementation of NAC may lead to improvement of goat udder health.