The investigation of correlation among selected biochemical parameters and vital signs in dairy herd to design the bio-cybernetic dairy cow model.

The paper presents investigations of the relationship between the biochemical parameters and vital signs in dairy cows. We analyzed the welfare and functioning of a dairy herd using biochemical parameters and vital signs. Life and biochemical parameters were examined. In the model indicators useful for monitoring the herd are: the age of the cows, the number of cows' lactating, daily amount of received milk, length of lactation period for cows in the herd, the length of inter-calving period for cows, the number of days to effective insemination, the amount of protein in the feed, the level of ß-oxidation in leucocytes, glucose transport through red blood cells and plasma insulin. Based on the results the mathematical model was designed allowing the presentation of a cybernetic model of cow's organism. There was constructed a multi-equation model which determined the relationships between the selected variables describing the state of dairy cows in the herd and variables that characterize their welfare with its statistical verification.

The influence of administration of biotin and zinc chelate (Zn-methionine) to cows in the first and second trimester of lactation on their health and productivity.

In cattle, the prevention of diseases might be possible using dietary methods, with nutritional optimization of feed rations. For years significant influence has been associated with the addition of biotin, methionine and zinc (each given individually, or as chelate - Zn-methionine). The aim of this study was to evaluate the influence of biotin or biotin + Zn-methionine additives on the health and performance of cows, in the first and second trimester of lactation. This study was carried out in 3 groups of cows, 30 animals in each group. In the first group cows were fed the usual fodder used on the farm. In the second group biotin at 10 mg/day/cow was added. In the third group both biotin at 10 mg/day/cow and Zn-methionine at 5 g/day/cow were added. The administration of biotin increased the milk yield and reduced the occurrence of retained placenta, as well as endometritis puerperalis. However, the high doses of biotin suppressed ovulation and oestrus symptoms in the investigated cows (low progesterone levels on days 15, 21 and 45 after calving). Zn-methionine in comparison to biotin had a lower effect on the milk yield in the cows. Moreover, its supplementation improved the milk content, as well as some of the blood parameters; it also decreased the number of somatic cells in milk. The concurrent administration of biotin and zinc-methionine seemed to be a good method for the prophylaxis of subacute mastitis and for the improvement of the high yielding dairy cows' productivity.

Effects of three cryopreservation methods and two semen extenders on the quality of dog semen after thawing.

The aim of this study was to evaluate the influence of two diluents, one with and the other without Orvus ES paste, and three methods of cryopreservation on the quality of dog semen after thawing. The investigation was carried out on 126 ejaculates collected from 37 dogs. In Expt 1, sperm-rich fractions of ejaculates were frozen in 0.25 ml minitubes and pellets. In Expt 2, each sperm-rich fraction of ejaculate was divided and extended in two diluents, one with and the other without Orvus ES paste. Samples of semen were frozen in pellets and 0.5 ml French straws. Motility, percentage of spermatozoa with normal acrosomes and longevity of spermatozoa were significantly higher (P < 0.05) in semen samples frozen in pellets than in samples frozen in 0.25 ml minitubes. Aspartate aminotransferase activity in extracellular fluid was significantly (P < 0.05) lower in semen frozen in pellets. There were no significant differences in quality after thawing between semen samples frozen in pellets and 0.5 ml French straws. Longevity, unlike acrosome status and aspartate aminotransferase activity, was greater in samples extended in Tris-buffered diluent with addition of Orvus ES paste, regardless of the method of cryopreservation.