Experimental material consisted of data concerning the course of calving in 1 094 Jersey cows kept in the years 1995-2001 at the Iwno Stud Farm. The percentage of difficult calvings, those assisted by a veterinary surgeon, and those using cesarean section was 9.68%. While analyzing the course of calving in terms of the division into primiparous and multiparous cows it was shown that difficult parturitions were twice as common in the group of primiparous cows than in the group of multiparous cows. A significantly higher percentage of animals in satisfactory condition was observed among primiparous cows and cows calving in winter and spring. No significant problems were observed with the departure of placenta, although it was found that this disorder was observed twice as often in multiparous cows and twice less often in cows calving in spring. Male calves were the cause of a slightly bigger number of difficult parturitions and all the cases of calving through cesarean section.

The performed experiments confirmed the increase in the number of somatic cells in milk of Jersey cows in consecutive lactations, although no significant differences were observed between individual lactation phases. The smallest number of cell elements was found in milk of cows, which calved for the first time between the 32nd and 34th months of life as well as in autumn and winter.

The aim of paper was to study some blood and urea metabolic profile factors in nutria and analyze them in order to defne the referential values. Tests were carried out at University of Agriculture, Cracow in 2002 using 9 young Standard nutrias (below 1 year) and 8 older ones. Blood and urea were taken during routine animal’s slaughter for skins. Analyses were performed in Medical Laboratory Center “Diagnostyka” in Cracow. Morphology of peripheral blood and Wintrob’s erythrocyte indices were determined in full blood. Differentiation of leukocytes, thrombocytes and thrombocyte parameters were also determined. Intracellular enzymes (ALT, AST, AP, γ-GT), glucose level, lipidogram, cholesterol and triglyceride contents were assayed in blood serum. Following physicochemical properties of urea were studied: transparency, color, density, pH, as well as presence of glucose, bilirubin, ketones, protein, urobilinogene and nitrites.

The study was carried on 6 rams of Wrzosówka sheep (3 years old), 15 rams of Wrzosówka sheep (5 mounths old) and 6 rams of crossbred Wrzosówka × Muflon, with 75% gens of Muflon. Samples of fibres hair were taken on autumn in 2002 yaear. The analyse thickness of the 200 fibres in every samples. In every group the significant differences were observed. The highest interest of down fraction was observed, in young rams (> 82%). The highest difference between groups of untipical fibres was observed. In rams of crossbred, interest of untipical fibres is more than 14%, instead, the least is in young rams group (1.2%).

The age at first calving of 5 634 cows maintained in individual herds of eastern Mazowsze in 1977-2000 were analyzed. The influence of genotype, calving year and production level on age at first calving and production level on age at first calving was investigated. The effect of age at first calving on primiparous FCM milk yield were analyzed too. The average age at first calving was 812 days. The high influence of holstein-friesian blood participation in cows genotype on decrease of age at I parturition were stated. The average age at first calving cows with high level of h.f. blood (> 50%) in genotype were 54 days shorter to the camper to the cows with lower h.f. blood participation. The influence of age at first calving on FCM milk yield (kg) were affected by cows production level. Among the cows producing in first lactation > 4 500 kg FCM milk the effect of age at I parturition wasn’t found.

The aim of the present studies was to determine the effects of synthetic amino acids added foxes were fed diets containing methionine, lysine and threonine in the amount of 2 g of each amino acid per 100 g of protein in the ration. Felting susceptibility was tested using the Aachen test. It was found that the experimental animals were characterized by lower felting susceptibility than the control animals.

The studies were conducted in 4 farms, managing the Hereford cattle. The results of rearing the calves, staying with their mothers on pastures and the body weight gains of the suckler cows during the grazing period, were determined. The daily body weight gains from birth till weaning in case of heifers varied from 0.720 to 0.879 kg and for bull calves from 0.736 to 0.962 kg. The body weight of heifers, as standardised to 210 days fluctuated from 184 to 219 kg and that of bull calves from 188 to 243 kg. During extensive utilisation of the pastures, the best results of rearing were obtained in the farms where free grazing was employed; the animals had there greater possibilities of chosing and intake of green forage, having a good feeding value. In these farms, the highest body weight gains of cows during their stay on pasture were found; they amounted to 0.286 and 0.255 kg, respectively. In the farms where the botanic composition of pasture forage was bad and the plot grazing and controlled (dosage) grazing was employed and the animals had the grasses in late vegetation stages at their disposal for a part of grazing season, body weight gains of the cows during pasture feeding season were equal to 0.158 and 0.179 kg, respectively.

The observations were carried out on a flock of 23 emus, kept in semi – intensive system, and fed according to the requirement during the reproduction season. The hatching rate was assessed for 72 eggs, gathered at the beginning (group 1), middle (group 2), and final (group 3) stage of egg laying. A constant incubation temperature (36.7°C)was maintained, the relative humidity in the incubator and hatcher being 30 and 40%, respectively. Every week the eggs were weighed to analyse their loss of weight. On termination of the incubation, indexes of hatching were calculated for the set eggs and the fertilised ones, and the number of dead embryos. Since the fertilization results of this study were good, free mating in the first reproduction season should be considered. Low indexes of hatching from eggs laid at the begin of the first production year indicate that these emu eggs should be used for consumption.

The study was conducted on 20 multiparous crossbreed Black and White x HF (50% share of Holstein Friesian blood) lactating dairy cows (2^rd-4^th lactation) with body weights of 650 ± 30 kg, during the first months of lactation and the milk yield 4 500-6 500 kg in previous lactation. The cows were assigned by an analogue method into 2 groups (10 cows in each), by making allowances for age, body weight, number of lactation, and the milk yield in previous lactation. The metabolic profiles and daily milk yield were examined on cows which were calved in winter feeding period (March) and in summer feeding period (July) in I and II month of lactation. The production rations were composed with maize and beet-top silage, lucerne with grasses hay, wheat ground, dried sugar beet pulp, molasses, wheat straw, lucerne with grasses g7reen and grasses pasture green. Mineral supplement were used occasionally. The mean level of glucose, calcium, phosphorus inorganic, magnesium and total protein in the blood serum were significantly less than the references data (2.66; 2.40; 1.64; 0,86 mM·L^-1 i 72.0 g·L^-1) and the lowest level were 2.03; 2.19; 1.22; 0.85 mM·L^-1 i 65.0 g·L^-1. The occurrences of ketone compound in milk in the I month of lactation in both groups were found. In II month of lactation the average daily milk yield of cows were significantly (p < 0.05) decreased by 2.0 kg (1.3 kg in winter and 2.7 kg in summer-time) and the predicted milk yield peak of lactation curve in the first month of lactation was disappeared. Supplement treatment feeds were considered and recommended for the prevention of production diseases. The metabolic profiles and daily milk yield control, may be very useful to protected of health and productivity of high yielding dairy caws in first months of lactation, when it is the integrity part of preventive medicine plane.

The aim of the paper was to define the impact of the value of daily gains of body weight standardized on 180th day, i.e. low or high on meat content of pigs (young boars and gilts) of following breeds: Polish Landrace, Belgian Landrace, Hampshire, Duroc, Pietrain and Synthetic Line 990 (which was treated as a breed) performance tested in the year 2000 in the region activity of Regional Animal Breeding Station (OSHZ) in Bydgoszcz. In young boars of Polish Landrace, Belgian Landrace, Hampshire and Pietrain were not stated significant impact of value of daily gains of body weight on body meat content. Similar trends were in case of gilts mentioned breeds, except Polish Landrace animals. The pigs of 990 Line (both young boars and gilts) and gilts of Polish Landrace and Duroc breed characterized by lower growth rate had higher meat content compared with animals with high daily gains of body weight. Only in case of young boars of Duroc breed were stated significant impact of high growth rate on higher body meat content.

The influence of red and white muscular fibres’ share in Semimembranosus muscles of cattle has been analysed. Slaughter mass ranged from 455.6 to 565.5 kg with bulls. And from 437.6 to 487.4 kg with heifers. In the experiment bigger diametre of white fibres has been observed although their share in the slaughter mass was lower than that of red fibres. Reported R indicator values reached lower level in case of muscles with lower red fibres’ share and higher white fibres’ share. The share of muscle fibres did not influence radically forming of the meat final pH₄₈, however a relation has been observed with pH₁ and pH₂₄. With pregnant animals bigger energetic transformation (R) has been reported. A reverse relation has been observed with meat acidification which was bigger with lighter animals. In Semimembranosus muscle with smaller share of red fibres and increased share of white fibres better WHC parameters have been recorded, especially with bulls. Increased dry mass content and intramuscular fat have also been observed, which resulted in increased marbling. Formation of red and white fibres’ share radically influenced meat colour. Meat of animals with increased amount of white fibres was lighter (10.76 and 11.26%).

Studies were conducted at Suffolk flock sheep located in the Podlasie area. The studies were carried reach over 1988 to 2002. The aim of this project was to compare the differences between the breed Suffolk imported com G. Britain and sheep brith, rearing and performance in Podlasie. Estimate the long the coefficients of relationship (0.015-0.078) which means that the purchased animals were not related. Fertility higher of ewes in the final year by about 29.3% from average country. The highest dailly gain was obtained lambs in period 2 to 56 days of age. The body weight in 100 days of age generally exceeded 30 kg irrespecive of sex. Average wool production in the population was the lowest in the country of analysis.

The choosen physiology and productive problems of lactation of sow were discussed. The mammogenesis, lactogenesis I, parturition, lactogenesis II, lactation and involution were characterized. The basic of molecular researches, hormonal metabolism, nutrition and apoptosis of epithelial cells of mammary gland were described.

The aim of the work was to analyse the factors which influenced fertility of chinchilla as well as to compare the fertility of chinchillas of standard, beige and black velvet types. The analysis of variance proved statistically significant influence of the breeder (breeding farm), year, animal age and colour type on the number of born and raised chinchillas. The highest arithmetic means were obtained by beige type: 2.15 of born and 1.83 raised in one litter. Standard type: 2.02 and 1.69, respectively. The lowest means characterised black velvet females. Results of reproduction are to be classified as satisfying. The number of born chinchillas in one litter varied depending on colour type. In standard type most frequently litters were composed of 2 (40.28%), 1 (31.17%) and 3 born (23.99). In black velvet type 51.52% of litters were characterised by 1 born and consequently 1 raised cub. In beige type litters were most frequently composed of 2 born (40.48); 3 and 4 cubs characterised 29.76 and 3.57 of litters, respectively. The estimated phenotypic correlations varied. Statistically significant negative correlations were between the number of born and females age (-0.180) and consecutive number of kittening (-0.167) as well as between the number of raised and females age (-0.209) and consecutive number of kittening (-0.153). It proves that the older females were characterised by lower number of born and raised cubs. Positive correlations were estimated between number of born and number of raised cubs (0.785). The results show that the females characterised by higher number of born cubs had also higher number of raised cubs. Coefficients of repeatability of traits of reproduction were low: 0.198 of born and 0.231 of raised. The estimated results were slightly higher than those presented in literature and suggest low but significant influence of genetic base on reproduction results in chinchilla females.

The aim of study was evaluation of reproductive utilization of chinchilla females on the oldest Polish chinchilla farm in Grywałd. Analysis covers 629 females of different color variety utilized reproductively from 1973 till 1993 and included such information as: 1) length of female reproductive utilization; 2) number and size of litter and; 3) juvenile death at delivery and weaning. Average length of female reproductive utilization was 2.26 years with mean 3.22 litters. The most females were utilized only 1 year (42%) and these females delivered only one litter (38%). Females lined twice (61.58%) or delivered only 1 litter during the served year (28.18%). The most frequent females delivered 2 (41%) or 1 youngness (39%); mean litter size during 21 years was 1.85 offspring included females in 58%. On the farm it was easy recognized existence of two periods of increased sexual activity. This seasonal character was observed also in offspring deaths.

The content of Lead, Cadmium and Nickel have been measured in muscles, livers and kidneys of New Zealand White (NZW) and New Zealand Red (NZR) rabbits raised in small-scale family farms in Silesia, heavy industry region of Poland. As a results of studies it was found, that kidneys are the most liable organ for bioaccumulation of each heavy metal, but especially of Cadmium. The accumulation of each heavy metal in muscles was low or very low. In all tissues Nickel accumulated in least of all. The results showed, that New Zealand White breed seems to be more resistant for bioaccumulation of heavy metals.