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Nutrition energy transfer from sows to piglets is unusually intensive in the suckling period. Due to this transfer, the sows increase their relative standard energy metabolism up to four times, that means to the boundary of the long-term sustainable maximum. They cannot cover these large energy outputs by feed intake, therefore they are catabolizing their own body tissues during suckling and lose about 15% of their live weight. Through milk, which is an energy-rich high-fat diet, up to 1.76 MJ/kg and day of energy (in the first week) are transferred to piglets, and/or up to 2.26 MJ/kg0.75 and day of energy (in the second week), which enables them to double their live weight at birth within the first 7 to 10 days. Milk transfer is of behavioral character in the system dam and litter. In a short time, it assumes a form of cyclic, collective synchronized suckling which is repeated more than twenty times a day and consists of several phases. But the piglets are able to feed not only on genuine milk but also from other sources from the second week of life. Then their weaning begins. They enter from the suckling period to a long, several-week period of weaning, in which some of their functional characteristics are changed fluently, others in a cascade manner. Proper, and to all participants adequate development of this transfer is depending on numerous circumstance which need not always be real. One of the reasons is that birth is such a large load for piglets that they cannot be competitive partners to their less loaded mates in the competition for sources of nutrition. Their participation in the unusually intensive, episodic, delicate transfer of nutrients conditioned by many factors is insufficient, full of failures. Hence they do not sufficiently utilize their growth potential, and do not often survive. Nevertheless, they are so functionally adaptable so that they can live without mothers, in isolation, being able to drink a liquid diet.

Cloprostenol, a prostaglandin F2-alpha analogue, used in the Czechoslovak preparation Oestrophan ing. Spofa was tested by a new nontraditional use. The effect of cloprostenol use on reproductive parameters of sows after piglet weaning was followed in a set of 456 experimental and 434 control sows. The effect of single intramuscular instillation of cloprostenol was tested in five partial observations: to multiparous sows at a dose of 175 micrograms on the day of weaning (experimental group no. 1), on day 1 after weaning (group no. 2), 500 micrograms on day 1 after weaning (group no.3), to primiparous sows at a dose of 500 microgram on day 1 after weaning (group no. 4). The treatment used in group no. 4 was also applied to 42 primiparous sows kept on a farm with regular occurrence of post-weaning anoestria of sows (experimental group no. 5). These parameters were evaluated: dynamics of oestrus onset within five, and/or ten, days after weaning, average length of the weaning--first insemination interval, conception rate after the first insemination in dependence on terminated deliveries and parameters of piglet litter. Cloprostenol application did not have a statistically significant effect on the evaluated reproductive parameters. The percentage of multiparous, and/or primiparous, sows in which the oestrus onset was not detected by the 10th day after weaning, did not show any large differences in the various experimental and control groups (17.09 vs. 16.55%, 23.53 vs. 32.56%, 13.66 vs. 18.13%, 29.54 vs. 30.30%; P > 0.05). On the farm with regular occurrence of post-weaning anoestria there were 73.81% of primiparous sows with oestrus onset after cloprostenol instillation and 71.43% primiparous sows without treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Sperm of 28 boars of the Landrace breed was evaluated with the help of the thermoresistance test (TRT). The principle of the TRT is that the sample of fresh sperm is left in a 38 degrees C bath for 120 min and after that time the activity of the sperm is evaluated. 308 ejaculates were evaluated in this way and 1342 sows were inseminated by these ejaculates after a short storage. The highest conception rate was stated after insemination with the sperm whose activity was above 50% at the end of the TRT. 366 of 400 sows became pregnant, i.e. 82.43%, whereas out of 370 sows inseminated with sperm whose activity was 0-30% at the end of the TRT only 269 conceived, i.e. 72.70%; difference was statistically highly significant. No statistically significant difference was recorded between the fertility (number of piglets per one litter) and the TRT results. A significant dependence was observed between the sperm survival after 72 hours and conception (P less than 0.05). The same significant relation was found between survival within 72 hours and TRT in fresh ejaculates. This justified the recommendation to introduce the TRT among the test used for evaluation of the quality of fresh boar ejaculate.

Trials were conducted with twelve piglets of the German Large White breed, intended for fattening. Their age was 56 +/- 2 days and their average weight was 21 +/- 3.7 kg. The piglets were studied for the effect of short fasting on the time and nature of sleep. After 18 hours of fasting (skipping the morning feeding), the piglets were fixed to obtain a combined record, including the electroencephalogram (EOG). This record was used for analyzing the time of waking and sleep, both the NREM stage and REM episodes. The same observations were performed in the piglets after feeding. The differences in the obtained data between the groups of animals were subjected to statistical evaluation. The fasting animals slept for about 15% of all the time under study and their sleep included short NREM periods interrupted by waking. No REM sleep was observed in the fasting piglets. After feeding the piglets slept significantly longer (p less than 0.01), more than half the period of study. Episodes of REM sleep occurred repeatedly in four animals. It is indicated by the results that fasting reduces the length of sleep and the nature of sleep.

The procedure of prevention of anoestria after the weaning of piglets was verified in 389 experimental and 332 control sows of the Prestice breed. The set of animals under study included 77 experimental and 122 control primiparae, 68 experimental and 71 control secundiparae, and 244 experimental and 139 control multiparae (i.e. sows with three or more parturitions). The experimental sows were treated with 1000 IU of serum gonadotropin ad usum vet.-Bioveta-(PMSG) the first day after the weaning of piglets and with 300 IU of chorion gonadotropin (HCG) in the Praedyn inj. Spofa preparation together with 1 ml of Dirigestran inj. Spofa (40 micrograms LHRH) 72 hours later. Control sows were not treated with hormones. The treated primiparae and secundiparae respectively, had a significantly higher percentage of oestrus onset within 10 days after weaning and lower occurrence of anoestria over 10 days after weaning by 31.25 per cent (P less than 0.001), and 21.36 per cent (P less than 0.02) respectively as compared with untreated controls. In the set of secundiparae, the studied hormonal treatment speeded oestrus onset by a significant (P less than 0.01) shortening of the interval from weaning to the first insemination by 0.79 day and by a more frequent onset of oestrus within only 5 days after weaning of piglets. The values of the other criteria of reproduction studies, i.e. percentage of pregnancies after the first insemination, total number of born piglets and number of liveborn piglets converted per one litter in treated primiparae and secundiparae did not differ significantly (P greater than 0.05) from the control.(ABSTRACT TRUNCATED AT 250 WORDS)

In a set of 154, and/or 260 ejaculates, collected from 72 boars, a relationship was studied between the activity of aspartate aminotransferase (AST) in seminal plasma and sperm concentration, and/or percent occurrence of morphologically abnormal spermatozoa. We failed to demonstrate any relation between the AST activity and sperm concentration (r = 0.023; P greater than 0.05). However, a statistically significant relation (P less than or equal to 0.05) was demonstrated between the AST activity and percent occurrence of morphologically abnormal spermatozoa (r = 0.343). Applying the above results and in agreement with literary data, determination of AST activity in the seminal plasma of boars can be considered as an important indicator of the cellular damage of sperms.

Biochemical indices were determined in 101 samples of endometrium taken from 16 praepubertal and 85 sexually mature gilts divided into four groups according to the stage of the cycle. On an average, glycogen content in praepubertal gilts was 3.354 mg/g-1 of fresh endometrium tissue, and in sexually mature sows 3.035 mg/g-1. A statistically and significantly higher value (4.066 mg:2.098 mg/g-1--P less than 0.01) was obtained in the luteal phase. Alkaline phosphatase showed a significantly higher level (P - less than 0.01) in sexually mature gilts than in praepubertal gilts (3291.2 mU.: :2457.7 mU). Reverse ratios were obtained (492.46 mU:687.8 mU.) in the content of acid phosphatase (P less than 0.01). In sexually mature sows the contents of AIP and AcP in endometrium were higher in the luteal phase (3624 mU. and 508.86 mU.:3085.7 mU. and 481.9 mU.). The differences between individual stages of the cycles were statistically insignificant (P less than 0.1). The content of lactate dehydrogenase (LDH) was slightly lower in praepubertal gilts than in mature sows (4.89 I.U.:526 I.U.). The highest content was found in late metestrus (7.682), and the lowest in sows in proestrus (4.494 I.U.). The difference was statistically highly significant (P less than 0.01). The role of these substances in endometrium and their regulation mechanisms are dealt with in discussion.

Fattened pigs were given standard diet containing 10% of crushed cake from white or red grapes. The replacement of part of the diet by this material was not found to exert any adverse influence on the health of the animals, evaluated according to slaughter characteristics. In most of the studied characteristics of the carcass and meat the difference between the control and experimental animals was not statistically significant and the meat of the animals had satisfactory nutritional and technological properties. The use of both kinds of grape cake resulted in the production of carcasses with a higher percentage of lean meat. The experimental animals also had a higher proportion of essential fatty acids in intramuscular fat.

Seventeen gonad pairs of boars and ten gonad pairs of bulls were examined to evaluate the migration of protoplasmic droplets and the phagocytosis of defective spermatozoa. The material for a microscopic investigation of secretions was collected from two sites in the testis and from seven sites in the epididymis. The greatest motion of protoplasmic droplets was recorded in the caput epididymidis, although the migration of droplets from the proximal section of the connective part of the flagellum towards the distal parts could also be observed as far as in the cauda epididymidis in both animals. A proximally located droplet still occurred in the cauda epididymidis in 4.5% of the spermatozoa of boars and in 1.9% of those of bulls. Absent mitochondrial spirals or swollen connective parts were observed in the imprints of testicular tissue in almost 50% of the spermatozoa whereas in the secretion of efferent ducts they were observed only in 0.3% of bull spermatozoa and about 3% of boar spermatozoa. No such defects were recorded in the epididymis head and tail in either of the two species. The marked reduction in the number of defective spermatozoa without mitochondrial spirals in the secretion of efferent ducts and after passage through the caput epididymidis testifies to the phagocytic ability of the epithelium of this part of efferent ducts.

Temperature conditions were measured with an electric dynamic catathermometer (EDC) and thermometers in pig farrowing houses 13 and 90 cm above the floor of the central and side corridors, boxes for sows and in piglet pens, heated with electric infra-radiators (input 525 W). The heat flow density of the EDC sensor, characterizing the cooling properties of the environment, was higher near the floor, at the ends of stables, on the sides exposed to wind, and after turning on the fan. The thermal conditions in the farrowing houses were therefore highly variable. In the piglet pens the heat flow density was usually kept at a very low level, owing to the thermal radiation of the electric infra-radiators, with possible bad implications for production. However, these facts cannot be documented just by the current measurements of air temperature.

In 1980 and 1981 tests were performed to verify the new methodical procedure of measuring heat flow by means of Alfameter and to evaluate the liberation of heat from the skin of piglets kept in two-storeyed cages in the finishing houses of the TEROZ TACHOV type. One of these houses was windowless, the other had windows. The temperature, humidity and flow rates of the air inside the houses were measured at the same time. The comparison of the two types of houses showed that under the given conditions the houses with windows implied a higher rate of cooling and a higher density of heat flow over the skin of the weanlings. In the windowed as well as windowless houses, the pigs in the upper row of cages showed a higher rate of heat liberation from the skin, as compared with the lower row. The piglets kept in the windowed house had lower gains and lower mortality rates.

The second fraction of boar ejaculate was thinned with six differently treated diluents of the Beltsville 3 type and with four diluents of the Ejadyl type containing Chelaton 3. All thinned sperm was kept at the temperature of +4 degrees C and +16 degrees C for 72 hours. At both test temperatures throughout the period of storage, diluents no. 4 and 9 (Beltsville type) and no. 8 (Ejadyl type) were found to be the best. No statistically significant difference was revealed between the mentioned diluents as to their effect. After 72 hours, progressive movement was observed, on an average, in more than 50% of spermatozoa in samples with the mentioned diluents.

Analyses were performed in 16 praepubertal and 85 sexually mature gilts of the Bohemian Large White breed. The content of dry matter in the endometrium of praepubertal gilts was 15.511%, on an average, and in sexually mature sows 11.968%, on an average, in the follicular phase, and 14.326% in the luteal phase. The differences are statistically highly significant (P less than 0.01). Considerable differences (mostly highly significant) were found also in the contents of calcium, phosphorus, magnesium, sodium, potassium, and chlorine in the dry matter of endometrium in praepubertal and sexually mature sows; however, these differences were less frequently dependent on individual stages of the sexual cycle. The highest content of calcium (1.112 mg g(-1)), phosphorus (8.357 mg g(-1)), and magnesium (0.720 mg g(-1)) in dry matter was found in gilts in the oestral phase, and the lowest in late or early metestrus (Ca = 0.625 mg g(-1), P = 0.6369 mg g(-1), Mg = 0.498 mg g(-1). Sodium showed the highest values in proestrus (23.359 mg g(-1)), and potassium in oestrus (13.012 mg g(-1)); their lowest values were recorded in late metestrus (Na = = 17.742 mg g(-1)) and in proestrus (K = 10.141 mg g(-1)). The content of these elements in endometrium dry matter was also much lower in praepubertal gilts than in sexually mature sows (with the exception of phosphorus); the difference was always highly significant.

Five trials involving 71 piglets and young porkers were conducted to test the toxic action of polychlorinated biphenyls (PCB) added to the complete feed mixtures as Delor 103, 105 or 106 (manufactured by Chemko Strázske) administered to the experimental groups. The intake of these biphenyls for 14 or 21 days at rates from 100 to 250 mg per kg of feed had no adverse effect on the health condition, production parameters and concentration of total protein, albumin, globulin, urea, glucose and cholesterol in blood serum. Delor 105 had the highest biological effectiveness: its intake increased the relative weight of liver, reduced the serum level of thyroid hormones and corticosteroids. When the weaned piglets consumed a starter feed with an addition of 1 mg of Delor 105 per kg (corresponding to a high natural PCB contamination) for 26 days, no adverse effect was recorded and, on the contrary, the growth of the animals was stimulated and their feed utilization was better. The results suggest that the young pigs are comparatively resistant to the toxic action of PCB.

Sperm motility, acrosome morphology, changes determined by the vital-lethal test and aspartate aminotransferase (AST) concentration in semen plasma were evaluated in the semen of four boars; the semen was stored for six years. No statistically significant changes in the percentage of motile spermatozoa were indicated when sperm motility was evaluated after four and six years of semen storage in liquid nitrogen. Neither did the fluctuation of the changes found on the basis of the vital-lethal test go beyond statistically insignificant values. After semen sample thawing in the BTS medium, the motility of spermatozoa was found to be somewhat higher than after thawing in the INRA-ITP medium, but after the termination of the thermoresistance test both media appeared to be equally effective. The AST level of the semen samples stored for four years was just slightly up on the initial values. After thawing in the BTS medium, AST level increased by 0.03 microcatal per litre of semen plasma, and in the INTRA-ITP medium by 0.06 microcatal per litre of semen plasma. The insemination of five sows with the semen stored for six years results in conception of two sows, i. e. 40%, and the average litter size was 7.5 piglets. It can be derived from the results that six years of boar semen storage in liquid nitrogen cause no further substantial changes in the structural and functional characteristics of spermatozoa.

In the years 1979 and 1980 the microclimate in two types of calving rooms AGRA was studied: rooms with and without windows. A comparison demonstrated that in the rooms with windows the air flow in the zone of abode of animals was higher, rather cooling the piglets, which was not desirable. The light and working conditions in this calving room were better. The temperature and moisture regime in the calving room with windows was influenced negatively because in spring and autumn the stable was cooled by cold outside air and in winter the air temperatures were reduced by heat removal through the windows. In the stable with windows the number of weaned piglets per sow was higher and the mortality rate was lower. The results of rearing are also influenced by the quality of piglet management.

Bilateral orchidectomy caused a marked decrease in the concentration of testosterone in the bood plasma of boars already in the early post-castration stage of three hours after the operation. In the period from 3 to 207 days after castration, the pre-operation levels of plasma testosterone decrease by 84.4%, on an average. Adreno-cortical compensation of the concentration of the hormone did not occur in the post-castration period. The conclusion is that the levels of testosterone in the blood of boars are mostly of testicular origin and can be considered as the main criterion of the incretion function of the testes. The discussion concerns the practical importance of the determination of testosterone levels in the blood of boars for clinical evaluation of the hormonal function of the testes and for diagnostics of incretion hypogonodism.

A yearlong evaluation of the semen volume, concentration and number of morphologically abnormal sperms of 1722 ejaculates from 53 boars of Large White, Duroc and Landrace breeds housed in one building was performed. Simultaneously, continuous registration of temperature and of the relative humidity of the sty climate was performed, and the cooling value and the air flow in the sty were determined. In the followed period also the conception rate of sows after the first insemination by semen of the studied set of boars was evaluated. In summer season, at the increased and high temperatures and the relative sty humidity and at the lower air flow, the lowest average volume of ejaculate, the highest average sperm concentration and the minimum average number of abnormal sperms were recorded. In winter season, from the microclimatic viewpoint characterized mainly by the optimum air temperature but by high relative humidity and by excessive air flow, the highest average ejaculate volume with a lower average sperm concentration and with a maximum occurrence of abnormal sperms was recorded. The parametric differences in ejaculate quality in summer and winter seasons were statistically significant, however, their variations did not exceed the spermiologic standard throughout the year. The found decrease in conception rate of sows after the first insemination by the semen of the followed set of breeding boars in warm months is obviously to be attributed to the sows or to the changes of other andrological criteria than those being subject of this study.

The meat and fat of slaughter pigs given diet with Ridzol P (60 mg per kg of feed) were studied. During the veterinary examination the additive was not found to have any adverse effect on the health of the animals. Judging from the studied meat and fat characteristics, there were no significant differences in the nutritive and technological value of the meat of the pigs given feed with Ridzol P, as compared with the controls. The additive was found to have a good influence on significantly higher weight of the cut lean parts. Hardly any difference was found in the proportions of the fatty acids of intramuscular fat, back fat and flare fat.

The effects of venepuncture or orchidectomy were studied, performed immediately after birth, on body weight, adrenocortical function, and some indicators of the metabolism in piglets, particularly at weaning at an age of four weeks and a fortnight afterwards. Neither venepuncture, causing the loss of ca. 7% of the total volume of blood, nor castration of the young boars exerted any adverse effect on the growth of piglets, which was rather stimulated during the sucking period in the first test. No significant differences between the experimental and control groups were found in adrenocortical activity and in the concentration of the total protein, urea, glucose, non-esterified fatty acids and cholesterol in blood plasma. The level of plasma 11-hydroxycorticosteroids showed a marked drop already a week after piglet weaning from the sow. The results are evaluated in view of potential subsequent implications of the neonatal stimulation of stress character. It was derived that neither the specific nor non-specific effects of the neonatal stress had adverse implications for piglets if the noxious dose was not beyond the adaptation and regulation abilities of the young organism.

In the course of the year, the temperature and relative humidity of the insemination hall of a large pig farm were studied in ten three-week periods. The results were compared with the conception rate of sows inseminated in these periods. The macroclimatic conditions were also studied, and the influence of macroclimate (including temperature and relative humidity) on the microclimate of insemination hall was evaluated. The studied microclimate parameters were found to influence the conception of sows in the first three weeks after insemination. Highly significant differences (significance level of alpha = 0.01) were recorded in the conception of sows after the first insemination, in the occurrence of optimum and increased temperatures, in the occurrence of optimum and increased relative humidity in the summer and winter months. A significant difference at the significance level of alpha = 0.05 was found when the occurrence of increased relative humidity was compared. A high temperature was recorded only in the summer months. In summer and in the first half of autumn (from the 9th of June to the 13th of October) when increased to high temperatures and increased to high relative humidity prevailed in the insemination hall (optimum temperature only in 2.0 to 23.3% of the period; optimum relative humidity in 11.1 to 50.0% of the period), the sow conception rate after the first insemination was low (45.5 to 49.7%). In autumn the microclimatic conditions in the insemination hall returned to the optimum. From the 4th of November to the 16th of February the optimum temperature (optimum in 71.6 to 89.7% of the period) and optimum relative humidity (optimum in 74.2 to 90.7% of the period) prevailed in the insemination hall, enabling an improvement in the conception of sows after the first insemination (71.4 to 80.1%). The temperature inside the insemination hall was influenced by changes in outside temperatures whereas the relative humidity inside the insemination hall was influenced mainly by internal factors.

The second fraction of the ejaculate of five boars of the Landrace breed was used for the experiments. Non-diluted semen was kept in hydrogen atmosphere for three hours at + 5 degrees C; then it was frozen in solid carbon dioxide into 0.1 ml, 2.0 ml, and 5.0 ml pellets and in liquid nitrogen vapours into the shape of disk or cylinder 5 ml in volume. The pellets were de-frozen on a teflon pan at 42 degrees C without addition of any other diluent. Ejaculate in which at least 25% of the spermatozoa were motile was considered to be usable. No statistically significant difference was found between the motility of spermatozoa frozen in the 0.1 ml and 2.0 ml pellets, but it can be said that on an average the motility of the spermatozoa was lower in larger pellets; this could be observed mainly in the pellets with the volume of 5.0 ml. Large differences were revealed in the freezability of the semen of different boars, irrespective of the size of the frozen pellet. Insemination of 38 gilts with semen from 2.0 ml pellets gave a 57,8 % concentration rate (22 gilts) and the average litter size was 8.25 piglets.

Ejaculate volume, sperm concentration, total number of abnormal spermatozoa, number of spermatozoa with protoplasmic droplet, and the content of chlorides, magnesium, calcium and testosterone in semen plasma were evaluated in 155 ejaculates obtained from 77 boars. Further, the evaluation included the fertilizing ability of the ejaculates, expressed by conception rate after the first insemination, average number of all piglets and live-born piglets in litter after inseminations with the studied semen. The following significant (P less than 0.01) relationships were found after the evaluation of the mutual correlations of the studied characteristics: ejaculate volume to sperm concentration (r = -0.496), chlorides to calcium (r = -0.240), chlorides to magnesium (r = -0.492), magnesium to calcium (r = +0.261), testosterone to conception rate after the first insemination (r = -0.222), boar age to ejaculate volume (r = +0.285), boar age to sperm concentration (r = -0.375), boar age to magnesium (r = -0.281), length of sexual rest to total percentage of abnormal spermatozoa (r = +0.323) and to the percentage of spermatozoa with protoplasmic droplet (r = +0.367). The importance of these findings is treated in discussion.

Laboratory trials were conducted to study the effect of various concentrations of cloprostenol on the motility and morphological changes of the acrosomes of boar spermatozoa. As found, a cloprostenol concentration of 250 ng per ml of semen to 2500 ng per ml of diluted semen has no adverse effect on the motility of spermatozoa and on the morphological changes of their acrosomes. The concentration of 5000 ng of cloprostenol (in the Oestrophan Spofa product) per 1 ml of diluted semen negatively influences the motility of spermatozoa. An insemination dose of 100 ml of diluted sperm treated with 500 ng of cloprostenol was used for the artificial insemination of 152 sows; 166 sows of the same farm inseminated with untreated semen were used as controls. No gilts were included in the trial. Out of the 152 test sows, 113 conceived after the first insemination, i.e. 74.35%, and the average litter size was 10.04 piglets. In the control group, 125 sows delivered their litters, i.e. 75.30% of the total number, the average litter size being 9.96 piglets. Comparing the reproduction parameters of the experimental and control groups it can be said that the treatment of an insemination dose with 500 ng of cloprostenol immediately before insemination had no influence on the pregnancy rate and on the size of litters.

By means of the Astrup equilibration method the values of the acid-base balance of the blood were determined in 104 cows, 99 horses, 100 pigs, 15 sheep, 20 goats, and in 101 dogs. The pH values of the blood, the partial pressure of CO2, the base excess, the base buffer, the standard bicarbonate, the actual bicarbonate, and the total CO2 were processed statistically and are presented in tables.