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The effects of an administration of the Zindep inj. preparation (Biotika) were evaluated in pregnant dairy cows as exerted on specific weight, total protein (TP) content, total immunoglobulin (IgC) and albumin (ALB) contents in colostrum. These parameters were also followed: calf's health, live weight, leucocyte (Lc) counts, T-lymphocyte (T-Ly) counts, contents of TPs, IgCs and ALBs in the blood serum of calves. Zinc concentrations were determined in colostrum, milk and calf blood serum. Our observations included 16 dairy cows in the seventh month of pregnancy in the second lactation and their calves in the winter feeding season. Eight experimental dairy cows were treated with the Zindep preparation in form of an injection to the neck muscles at a dose of 3 mg Zn/kg live weight in the mid-seventh month of pregnancy. Blood samples were taken from v. jugularis from all calves before their first drinking, on days 5, 15 and 30 of age. Colostrum, and/or milk samples were obtained by drawing of the colostrum or milk from the udder quarters within 60 minutes after parturition, on days 5 and 15 of lactation. Zn levels at birth were 16.48 +/- 2.67 mumol/l in experimental calves and 13.84 +/- 3.19 mumol/l in control calves. Zincaemia decreased slightly in both groups on days 5 and 15 of age, but it was insignificantly higher in calves coming from Zindep-treated dairy cows. Zn levels in the blood serum on the 30th day of age were 18.45 +/- 2.44 mumol/l in experimental animals and 15.73 +/- 3.11 mumol/l in control animals. Zn content in the colostrum of experimental cows was 2.40 +/- 0.42 mg/l and in the control it was 1088 +/- 0.52 mg/l (P < 0.05). On day 5 of lactation, Zn amounts in the milk of experimental dairy cows decreased to 0.95 +/- 0.12 mg/l and to 0.76 +/- 0.10 mg/l in the control (P < 0.01). Zn levels in the milk of experimental cows on day 15 of lactation were 0.95 +/- 0.13 mg/l and in the milk of control group they were 0.82 +/- 0.14 mg/l. Colostrum specific weight from zinc-treated cows was 1,067.86 +/- 0.75 g/cm3 and 1,056.8 +/- 13.53 g/cm3 in the control. TP and IgC concentrations were 137.81 +/- 38.11 g/l and 110.13 +/- 29.91 U ZST, respectively, in the colostrum of experimental group, and 105.98 +/- 32.02 g/l and 85.53 +/- 25.42 U ZST, resp., in control animals.(ABSTRACT TRUNCATED AT 400 WORDS)

The concentration of total volatile fatty acids (VFA) in the rumen fluid were increasing with the age of the animals (Fig. 1). A significant increase in the concentrations of total VFA (P less than 0.01) from 70.93 to 90.71 mmol/l was observed in the age period of 5-7 weeks and a highly significant increase (P less than 0.001) in the age period of 9-11 age. At the average age of seven weeks the lower boundary of the reference value range (80-120 mmol) of the total VFA concentrations in the rumen fluid as mentioned for adult animals was exceeded in the experimental calves. As to this parameter in individual calves, the level of the total VFA concentrations in the rumen fluid of adult animals was not reached in 50% of calves at the age of three weeks, in 80% of calves at the age of five weeks, in 20% of calves at the age of seven weeks and in 10% calves at the age of nine weeks. At the age of 11 weeks the concentrations of total VFA reached the level of adult animals in all experimental animals (Fig. 2). The molar proportion of acetate (Fig 3) decreased from 74.04 mol% at the age of three weeks to 67.54 mol% at the age of 11 weeks, and the propionate proportion increased from 16.73 to 19.53 mol% within the same interval.(ABSTRACT TRUNCATED AT 250 WORDS)

Ovarian functions are regulated by a wide variety of substances of hypothalamic, pituitary and intraovarian origin. In particular, prolactin (PRL) plays an important role in the control of ovaries. The aim of our in-vitro experiments was to prove a possibility of PRL production by bovine granulosa cells and to search into the endocrine regulators of this process. In the course of experiment 1 it was observed that the marked time-dependent accumulation of immunoreactive PRL took place during long-time cultivation of granulosa cells both in serum-free and in serum-dependent medium. After 12-24 hours of cultivation this level was reduced, but after 120 hours of cell culture the medium PRL-immunoreactivity gradually rose to exceed the starting level 2.1-2.4 times. FSH additions (10-10,000 ng/ml) led to a dramatical rise of PRL-immunoreactivity in a dose-dependent manner. A greater increase in FSH doses (1000 or 10,000 ng/ml) activated this process 14.0-18.0 times. In the other experiments the effects of LH, LH-RH and various nonapeptide hormones on the PRL-like substance production were investigated. LH stimulated PRL-like substance production at a great dose only (10 IU/ml). The lower doses did not have any significant influence on the process. Low doses of oxytocin (1 or 10 IU/ml) blocked, and higher doses (100-1000 IU/ml) stimulated the granulosa PRL-like production. Arginine-8-vasopressin (AVP) (1-1000 ng/ml), arginine-8-vasotocin (AVT) (10-1000 ng/ml), or LH-RH (10-10,000 ng/ml) failed to influence the immunoreative PRL accumulation in the culture medium.(ABSTRACT TRUNCATED AT 250 WORDS)

23 cows of the Holstein-Friesian breed during second lactation were used in the experiment. All animals were housed in one stable with tying. The blood was collected from each cow four times during first to third, fourth to sixth, seventh to ninth and above nine months of lactation. After 305 days of lactation, the milk cows were classified as with high (n = 14) and lower performance (n = 9), the limit value was 5000 kg of milk. The difference in milk production between groups was highly significant even during the period of the first 90 days (501 kg) and this difference increased for 305 days of lactation to 1538 kg (Tab. I); the dairy cows with high performance produced 6162 kg of milk per 305 days and that with the lower performance gave 4624 kg during the same period. Another significant differences occurred in the fat contents per kg and in the amount of milk converted on 4% fat content. During the first stage of lactation a slightly higher haemoglobine level was found in cows with high performance, the opposing results were obtained in another studies (Tab. II), the highest difference was recorded in the course of 7th to 9th month. The level of total protein was, except 7th to 9th month, always higher in cows of the first group. The difference was significant at the beginning of lactation. Insulin concentration (INS) exhibited identical tendency for the whole lactation--dairy cows with high milk production exhibited lower values, significant differences were recorded in the first observation at the beginning of lactation and in the period above 9 months. Similarly as in case of insulin, it is also in hormones of thyroid gland, the cows with high milk capacity had the lower values (Tab. III). The highest differences in triiodothyronine (T3) concentration were recorded in the second half of lactation, significance ranged from 7th to 9th month of lactation. In thyroxine content (T4), marked differences were recorded during the first and last observations, the difference was highly statistically significant during the seventh to ninth month of lactation. The levels of cyclic adenosine monophosphate (AMP) were higher for the whole experiment in animals with lower milk production. Tab. IV gives the correlation coefficient of different parameters between periods under study. Almost all parameters are in a close positive relation, the closest dependences were observed between second, third and fourth periods in hormones of thyreoidea. The most significances were recorded in adenosine monophosphate, thus confirming its stability of minimum variance between observations.(ABSTRACT TRUNCATED AT 400 WORDS)

Various surgical techniques and two types of fistulas were tested when they were installed (Firm and PVC rumen cannulas were applied in 35 and 12 animals). We consider that the simplest process of installing the fixed rumen fistula is the total resection of abdominal wall together with peritoneum and following fixation of rumen to the abdominal wall with knot stitches and with removal of rumen wall between the stitches in the shape of circle. This process can be mastered by two people without particular equipment in approx. 30. minutes. When installing the PVC fistulas we prefer their fixation in rumen with help of seromuscular circular stitches followed by leading out the fistula off the main cut.

The fertility of cows and health of calves are influenced by a number of factors, including the technological systems and quality of nutrition. The effect of nutrition was studied in two selected herds with different technological systems during 1986 to 1987. The feed rations were found to be non-standard, the nutrient ratios were not balanced, and the animals suffered from different stages of metabolic disorders. These disorders were worse in the H. large-capacity barn, equipped with modern technology, in comparison with the S. barn with traditional technology. The better reproduction data recorded in the S. barn, using the traditional technology, are ascribed to better organization of work, better feeding, and better care of the animals. The production of viable calves is the most vulnerable point in the reproduction process. Great reserves were found to exist in both the herds studied. The shortcomings suggest that knowledge of the factors and the causes of losses during the year seasons is a prerequisite for tracing the aetiology and taking effective measures, which in turn will influence the weaning. If fertility is to remain high, fertility disorders must be treated in time. As the analyses show, uterus diseases are diagnosed most frequently under farm conditions; their occurrence is associated with the hygiene of parturition and generally with hygiene in the barn. The set of recommendations to improve the reproduction process in the two herds influenced the economy of the farms.

Changes in the concentration of 17beta-oestradiol (E2) and luteinizing hormone (LH) and in the rectal and vaginal temperatures (RT and VT) were studied along with the changes in thyroxine concentration (T4) in three cows and three heifers in the luteal stage of the cycle; the animals had been intramuscularly treated with 2 ml Oestrophan (cloprostenol). The closeness of the correlation between T4 and the remaining parameters under study was determined by the calculation of the correlation coefficient and statistical significance. The concentrations of T4 before and during cloprostenol administration were high in comparison with the post-treatment levels. E2 concentrations at cloprostenol administration time were much higher than those recorded before administration. After treatment the concentrations of T4 and E2 sank. The first E2 peak, recorded in the 44th hour, was immediately followed by a marked drop of E2 as well as T4, the lowest values of both being recorded in the 52nd and 56th hour. The second peak of E2 in the 60th hour was followed by a slow but steady decrease. The rise of the concentration of T4 after the 56th hour was slow and reached the peak in the 74th hour; after a partial decrease no further marked changes in concentrations were recorded. LH concentrations rose at a slow rate to reach the peak in the 64th hour. After a rapid decline they reached the pre-peak value in the 70th hour. The lowest RT and VT levels were recorded in the 54th and 94th hour. It can be assumed on the basis of the behaviour of the hormones and the evaluation of their correlations that thyroidal hormones are involved in the stimulation of the synthesis of ovarial oestrogens which tend, after their synthesis, to eliminate from circulation the T4 as well as their own levels and thereby to influence (as feedback) the stimulation of T4 synthesis, their own synthesis, and LH.

Oestrus synchronization was studied in samples from six cows of the Black-Pied Lowland breed. Three cows four to five days from oestrus were used as the control; three animals with marked periodic corpora lutea were given an i. m. injection of 0.5 mg cloprostenol. The eighth day from the administration of the preparation, the ovaries of the cows were excised and, after histological processing in a simultaneous series in a 4mm interval, the preparations were subjected to qualitative and quantitative microscopic evaluation. The structure of non-atretic and atretic follicles was described in different stages of the atretic process. The lymphoid cells of atretic follicles were observed to penetrate into the granulosa membrane. A multiplication of non-atretic tertiary follicles was observed after the administration of cloprostenol. This multiplication was more pronounced on the right ovary where the preceding ovulation had taken place (P less than 0.01). The treated animals, compared with the controls, showed a significant multiplication of tertiary follicles at early atresia and at total collapse atresia (P less than 0.001), whereas the number of follicles with contractive atresia showed a significant decrease (P less than 0.001). The results suggest that cloprostenol can influence follicle population mostly through the stimulation of the growth and ripening of tertiary follicles; its modulation effect seems manifest itself in cooperating relation with gonadotrophic hormones, mainly with the follicular secondary hormone (FSH), in the theory of the complex effect of proteohormones .

Two groups of fattened bulls (125 bulls in each group) were investigated for the effect of monensin (125-175 mg per head/day) on live weight gains and for the effectiveness of monensin administration. After 160 days of fattening, the average daily weight gain was 713 g in the control group and 800 g in the monensin-treated group (an increase by 12.2%). After 11 months of fattening the daily weight gain was 702 g in the control group and 768 g in the monensin-treated group (an increase by 9.4%). Besides the control and experimental groups, monensin was administered to 1500 head of fattened cattle on the whole. Greater differences in the daily live weight gains (higher gains in the monensin-treated animals) were recorded mainly in the period when the feed ration contained high-quality bulk feeds. When the bulls were given feeds of lower quality (mainly late in winter), the differences in the average daily live weight gains decrease and the effect of monensin treatment is not so great. Throughout the fattening period, monensin had a favourable influence on the live weight gains and its use was economically advantageous.

We evaluated the ovaries of 34 cows cross-bred of the Slovak Pied and Lowland Black-pied breeds which were culled and intended for slaughter during the winter type of feed rations. For superovulation treatment we used PMSG in the preparation Serum Gonadotropin (Bioveta, Nat. Ent., Ivanovice na Hané) and cloprostenol in the preparation Oestrophan inj. Spofa. We weighed the excised ovaries, fixed them in formalin 10% and made a quantitative evaluation of the surface follicles and differentiated them into recruited and selected or dominant follicles. We determined the concentration of 17 beta-estradiol and testosterone with the aid of the 3H RIA set from the firm Sorin after extraction by diethylether with separation of free and bound hormone with active charcoal. 72 hours after the giving of cloprostenol 43% reacted positively to superovulation treatment and after seven days a 50% positive response was recorded. After a dose of 2000 i. u. of PMSG (n = 6) embryo was obtained, whereas after 3000 i. u. of PMSG (n = 8) we flushed out eight embryos, of which four zygotes were suitable for transfer. After a higher dosage of PMSG there was an increase in the average weight of the ovaries, in right-hand ovaries significantly with P less than 0.05. After super-ovulation treatment the concentration of 17 beta-estradiol (E2) in the follicular fluid from follicles seven days after insemination was found to be so low as to be below the limit of detection, with the exception of four samples (mean = 8.60 nmol.l-1). The greatest concentration of E2 was from animals (n = 5) 72 hours after the giving of cloprostenol--1099.61 nmol.l-1) of follicular fluid. The concentration of testosterone was lower in the follicles of untreated cows in the follicular phase (mean = 5.92 nmol.l-1) compared with the follicles of super-ovulated animals the seventh day after insemination (mean = 14.12 nmol.l-1). The number of recruited and especially selected surface antral follicles 72 hours (n = 7) after the giving of cloprostenol and seven days (n = 8) after insemination was significantly higher in the group of brood cows reacting positively to superovulation in comparison with the animals which did not respond. It appears that the simultaneous monitoring of hormonal and morphological changes in the follicular system will help in objectivising the evaluation of the functional activity of stimulated follicles.

Superovulation response was studied to i. m. administration of 2500 and 3000 i. u. of PMSG (special product Folligon, Intervet Co.) in 67 breeding cows of the Black-Pied Lowland. Slovak Pied and Slovak Pinzgau breeds within the 9th to 12th days of their sexual cycles. The time which had elapsed from these cows' last calving ranged from 50 to 150 days and the number of their prior calvings ranged from one to ten. The best superovulation effect was obtained after the administration of 2500 i. u. PMSG in the Pinzgau breed: these cows had, on the average, 13.20 +/- 2.36 corpora lutea without non-ovulated follicles. At the PMSG dose increased to 3000 i. u., the number of yellow bodies rose to 18.11 +/- 1.12 and that of non-ovulated follicles to 3.46 +/- 0.46. In the Slovak Pied breed the average number of yellow bodies obtained after administration of 2500 i. u. PMSG was 11.74 +/- 1.27 and that of non-ovulated follicles was 0.44 +/- 0.02. At the PMSG dose of 3000 i. u., the number of yellow bodies increased to 15.49 +/- 1.62 and that of non-ovulated follicles increased up to 5.12 +/- 0.81. In the Black-Pied Lowland breed the lowest response was obtained: the i. m. administration of 2500 i. u. PMSG resulted in the formation of 9.5 +/- 0.84 yellow bodies and 1.16 +/- 0.26 non-ovulated follicles, and at the dose of 3000 i. u. the respective numbers were 13.41 +/- 0.89 and 3.07 +/- 0.39. Comparing the superovulation effect in dependence on age, the response of the cows of the Black-Pied Lowland and Slovak Pinzgau breeds to PMSG administration increases until the age of nine years (from 9.79 and 13.6 yellow bodies, respectively, on the average for the first five years to 12.71 and 17.99, respectively, in the ninth year); in the Slovak Pinzgau breed it decreases from 15.83, recorded in the first five years, to 8.28 +/- 1.68 in the ninth year. The number of non-ovulated follicles grows with age in the Slovak Pinzgau breed from 3.46 +/- 0.46 in the first five years to 3.64 between five and nine years of age and up to 4.44 +/- 0.52 after the ninth year, in the Slovak Pied breed from 0.79 to 4.21 +/- 0.38, and in the Black-Pied Lowland breed from 2.69 to 3.20 +/- 0.22 between the fifth and ninth year.

Trials were conducted to study and describe the micromorphological parameters of endometrium in five cows of the Black-Pied breed after the expiration of the synchronizing effect of cloprostenol in the Oestrophan inj. Spofa preparation. Two animals four to five days after oestrus were used as control and three cows on the sixth day of sexual cycle with rectally palpated corpora lutea were treated intramuscularly with 0.5 mg cloprostenol in 2 ml of Oestrophan. On the eighth day from the administration of the product, samples of uterine horns were obtained by necropsy and were subjected to histological preparation. Paraffin slices, 7 micron thick, were stained with haematoxylin-eosine by the PAS reaction. Changes were observed in the ipsilateral and contralateral uterine horns in relation to active corpus luteum. A state resulting from previous oedematization, with ample thin connective tissue and fading cell infiltration after the administered preparation, was described in the subepithelial layer of endometrium. The occurrence of intraepithelial lymphoid cells was observed in the surface epithelium of endometrium. A significant increase in the thickness of endometrium (P less than 0.001) was observed to persist on the eighth day after the administration of cloprostenol. An increase in the thickness of surface epithelium, ipsilateral with the corresponding corpus luteum, was on the level of significance (P less than 0.05). The subsurface cells of endometrial glands shrunk significantly after the administration of the preparation, both ipsilaterally (P less than 0.001) and contralaterally (P less than 0.001) to the corpus luteum, like in the glands in the depth of the mucous membrane just above myometrium (P less than 0.01). The occurrence of intraepithelial lymphoid cells decreased significantly after the administration of cloprostenol.

Two groups of bullocks, each consisting of 125 animals, were subjected to a trial to study the effect of monensin (Rumensin premix) administered at doses from 125 to 175 mg per head/day on rumen fermentation and weight gains. For 135 days the animals were given a diet based on green juicy forage with a supplement of chopped straw and concentrate mixture; this mixture contained 20-30% of dried poultry droppings. In the experimental group with monensin, the concentration of total and protein nitrogen and the molar percentage of propionic acid significantly increased (23.7 and 28.5%, respectively, P less than 0.01) and the acetate: propionate ratio decreased four hours after feeding. Further, the energy yield of the production by volatile fatty acids (VFA) significantly increased in the rumen contents (76.89%, 78.64%, respectively, P less than 0.05). The levels of ammonia and non-protein nitrogen were not affected by the addition of monensin. The average daily live weight gains were 713 g in the control group and 800 g in the experimental group; this means that the gains of the experimental animals rose by 12.2%. Monensin had a positive influence on the proportions of the rumen-produced VFA in favour of propionic acid which, in turn, favourably influenced the energy balance of nutrient conversion and efficiency.

We determined the thyroxine (T4) concentration in 63 heifers on 0th (day of insemination), 6th and 21st day after first and in repeat-breeder cows after second and third insemination in relation with the breed, age and weight of animals. The examination was carried out with a feed ration balanced according to the Czechoslovak State Standard CSN 46 7070, with all-the-year-round housing, with keeping the uniform time of insemination (8.00--9.00 a. m.) as well as the time of blood sampling (10.00--12.00 a. m.). The animals were inseminated from August to November. The average T4 concentrations, with a successful insemination, fluctuated on 0th day after first, second and third insemination at levels of 56.15 +/- 13.6; 84.6 +/- 10.66 and 89.75 +/- 13.62 nmol X l-1 of serum. As the results show, the lowest T4 concentrations (P less than 0.001; P less than 0.001) on 0th day were recorded in animals becoming pregnant in first insemination. The comparison with non-pregnant animals did not show any statistically significant difference in T4 concentrations. On 0th day of the second insemination, the T4 concentrations in pregnant animals were higher (P less than 0.01) as compared with non-pregnant. On 6th and 21st day after successful first insemination the T4 content increased significantly (P less than 0.001). After second and third successful insemination we recorded in T4 concentrations a moderate decrease on 6th day (P less than 0.01 for third insemination), with insignificant increase on 21st day.(ABSTRACT TRUNCATED AT 250 WORDS)

A negative relationship of glutamic acid content and milk yield over the first 100 days of lactation was found in a set of 20 cows. In some free amino acids, large differences exist between the cows with the higher milk yield and those with the lower milk yield, the largest difference being recorded in the content of glutamic acid (in favour of the cows with the lower milk output). The group of cows with the higher milk output per day or per first 100 days of lactation showed no dependence on any of the free amino acids in milk. The group of cows with the lower milk yield showed a significant negative relation of glutamic acid content to milk yield over the first 100 days of lactation and a significant to highly significant positive relation between serine, threonine and alanine contents on the one hand and daily milk yield on the other.

In thirty-three dairy cows--first calves, the influence of hypokinesis on biochemical parameters was studied over three lactation periods. The cows of the experimental group (n = 15) were reared in steel cages enabling only minimum movement, whereas the control group (n = 18) was housed loosely. It was found out that the permanent movement restriction led to a statistically significant decrease in hemoglobin and hematocrit concentrations, as well as in aspartate aminotransferase activity. In comparison with the control group, a significant decrease was also observed in substances of the lipid group--cholesterol, triglycerides and total lipids. Similarly, thyroxin and total proteinemia were lower.

The effect of beta-carotene was studied, as exerted on the amount, ductility, pH value, arborization and sperm survival time in the medium of the cervical mucus of heifers included in the breeding stock. The measurements were taken during oestrus and mating. The animals were divided into four groups. The first group was given diet containing no carotene. In the other groups (II, III, IV) the animals were fed a supplement of synthetic beta-carotene, the doses being 100, 200 and 400 mg per head/day. The survival of spermatozoa in the medium of cervical mucus was found to be significantly longer in the fourth group (115.2%) as compared with the first group (61.8%). In the statistical comparison of these results the P level was less than 0.05. Statistically significant differences were observed in the amount, ductility and arborization between the pregnant heifers and oestrus return ones in the first group. These differences were reduced after the addition of beta-carotene to feed. Beta-carotene saturation in the feed ration was not found to exert any significant influence on the pH value of cervical mucus. As suggested by the evaluation of the results and their comparison with literary data, sperm survival time in cervical mucus was the only trait influenced significantly by beta-carotene: no significant effect was exerted on the other parameters under study. Beta-carotene seems to influence the role of polyfactorial factors in the control of steroidogenesis.