Fulltext search in archive

The study was conducted to evaluate the potential cryoprotective effect of butylated hydroxytoluene (BHT) through post-thaw evaluation of canine semen and its optimal inclusion level. Ejaculated canine semen was extended in TRIS-glucose egg yolk extender containing various concentrations of BHT (0.5, 1.0, 1.5, 2.0, and 2.5mM). Semen was frozen at -196°C using 200 × 10⁶ spermatozoa per 0.5 ml straws and post-thaw evaluation was carried out in terms of sperm motility, viability, plasma membrane integrity, and acrosomal integrity through phase-contrast microscope, supravital staining, hypo-osmotic swelling test, and normal acrosomal ridge, respectively. BHT was found to improve (P > 0.005) all post-thawed semen quality parameters at an inclusion level of 1.0mM in the extended semen. However, higher concentrations than this were found to have detrimental effects.

Pigs fitted with ileal T-cannula in the terminal ileum were used to study the effect of synthetic amino acids (AA) added to a nitrogen-free diet on endogenous losses. We compared the obtained data with data from other research centres in the world that are focusing on these problems. In the present experiment, we used three synthetic diets - a nitrogen-free (NF) diet, a diet with added essential AA (E), a diet with the same amounts of essential AA and a mixture of non-essential AA (E+N) added. The diets, apart from the amount of AA, had the same composition. Chromium oxide was used as an indigestible marker. The supplementation of the NF diet with sulphur AA, threonine and tryptophan resulted in a reduction of the endogenous flow of all AA except for cysteine. However, the difference between the NF and E diet was significant only in the case of proline. The effect of the non-essential AA addition to diet E was negligible, even though the endogenous flow of most AA tended to decrease. In comparison with NF diet, the endogenous flow of total N in diets E and E+N was reduced by about 30%. This reduction was mainly due to the decreased endogenous flow of proline, which accounted for 59% in diet E and 55% in diet E+N. Proline was the most abundant AA in all diets, followed by glycine and glutamic acid. The sum of proline and glycine in diets NF, E and E+N amounted to 59, 44, and 46% of total AA flow, respectively. In contrast, the proportion of the sum of essential AA of total AA flow in diets NF, E and E+N was 21, 28 and 27%, respectively. Our data on the endogenous AA and N flow are in the range of previously published values.

The objective of this study was to determine how the concentration of milk urea (MU) and FPCM production affect reproduction in selected Holstein dairy herds in the Czech Republic. A retrospective, observational study comprising analyses of individual cow records from monthly dairy herd improvement (DHI) milk tests including milk urea (MU) concentration was conducted in six commercial Holstein dairy herds in cows that were bred from July 2000 to August 2003. A total of 1 333 cows with available breeding date, pregnancy status, and calving to first service interval from 31 to 150 days were selected. The data were evaluated using the mixed linear model and logistic analyses. The effect of MU concentration on the probability of conception at first service was not significant (P = 0.11). The results indicated a nonlinear relationship between MU concentration and the probability of conception. A significant effect of the length of calving to first service interval (P < 0.05) and FPCM (P < 0.05) was determined. The cows with the calving to first service interval longer than 2 months had higher probability of conception (10% higher). In the group with the highest FPCM a markedly lower level of successful pregnancy was determined (38.99%), which significantly differed from the group with average FPCM production (48.53%). The probability of conception at first service in the group with the lowest FPCM is at an average level (43.55%).

The objective of this experiment was to test a hypothesis that L-carnitine supplemented diet would improve semen characteristics in 6 adult crossbred AI boars (Hampshire × Pietrain). The control and the tested diet were identical except the tested period (8 weeks) when the diet was supplemented with 2 g of L-carnitine per boar per day. The semen was collected regularly weekly by a gloved-hand technique. Semen volume, sperm motility and concentration, proportion of alive sperm cells and aspartate aminotransferase (AspAT) activity of semen were determined immediately after the semen collection once every two weeks. Sperm survival rate, morphologically abnormal spermatozoa, seminal plasma mineral components and free amino acid concentration, L-carnitine concentration in semen plasma and in sperm cells were determined after the sample storage (-20°C) at a later time. The differences ascertained between the average values of semen characteristics in the control vs. tested period did not prove a true and unambiguous positive effect on boar semen parameters by dietary supplementation of L-carnitine as our data show in our study: volume (239.11 vs. 250.50 ml; P 0.518), sperm concentration (301.67 vs. 350.83 × 10³/mm³; P 0.309), sperm progressive motility (66.94 vs. 70.00%; P 0.409), morphologically abnormal spermatozoa (29.00 vs. 27.46%; P 0.802), daily sperm cells output (9.86 vs. 11.71 × 10⁹; P 0.206), proportion of alive sperm cells (72.56 vs. 74.13%; P 0.484), survival spermatozoa ability maintenance (43.29 vs. 38.68%; P < 0.01), mineral components in the seminal plasma (Na-, K-, Ca-, Mg-, Zn-; P from 0.138 to 0.968), AspAT activity (in semen plasma - 132.50 vs. 128.31 mU/10⁹ spermatozoa; P 0.830, in sperm cells - 147.37 vs. 119.01 mU/10⁹ spermatozoa; P 0.146), semen plasma amino acid concentration - a significant positive effect of L-carnitine in lysine only (0.79 vs.1.17 μmol/100 ml; P < 0.01), L-carnitine concentration (in semen plasma 255.40 vs. 259.97 mg/l; P 0.884, in sperm cells - 1 110.68 vs. 883.58 mg/l; P < 0.01). In conclusion, the studied indicators of semen quality were not significantly enhanced by dietary supplementation of L-carnitine in adult AI boars.

The purpose of this study was to analyse the microbial diversity in the caecum of geese using a 16S ribosomal RNA gene (rRNA) clone library approach. A total of 160 clones and 124 clones were sequenced and phylogenetically analysed from the contents and mucosa of the caecum of Yang Zhou geese, respectively. The result indicated that there was a rich variety of bacteria in the caecum contents. Forty-six operational taxonomic units (OTUs) based on a 98% similarity criterion were classified in the contents of goose caecum, as compared to 29 OTUs based on a 97% similarity criterion in the mucosa of goose caecum. The sequences were assigned to 7 and 5 groups in the contents and mucosa of goose caecum, respectively. Contents of goose caecum were dominantly occupied by Clostridia-related species (58.7%) with other abundant sequences being related to Bacteroidetes (26.9%) and Erysipelotrichi (11.2%). Gammaproteobacteria (59.6%) and Clostridia (20.1%) were predominant in the mucosa of goose caecum.

Growth and survival rates (specific growth rate - SGR; survival rate - S) of Barbus barbus L. were recorded in captivity during three years from the larval period (final body weight - W = 0.2 ± 0.03 g; SGR = 13.6 ± 1.1%/day and cumulative survival - S = 76.0 ± 2.5%) to the first reproductive season (W = 62.55 ± 13.5 g; SGR = 0.89 ± 0.05%/day; S = 59.3 ± 1.5%). Final body size and SGR were compared between both sexes. Females reached the significantly higher growth rate (SGR = 0.84 ± 0.01%/day) compared to males (SGR = 0.77 ± 0.01%/day). Early puberty was observed in 17 and 32 months old males and females, respectively. Multi-stripping activity was found out in both sexes during the first reproductive season. In total, 20%, 25.8%, 30.3%, 14.6% and 9% of females were stripped once, twice and three, four and five times, respectively. But all males produced sperm during the entire reproductive season. The highest and the lowest egg production was recorded in the middle (April) and at the beginning (March) of the reproductive season (2155 ± 925 vs. 1279 ± 298 eggs per stripping). The highest and the lowest sperm production was observed at the beginning (March) and at the end (May) of the reproductive season (7.9 ± 0.08 × 10⁹ vs. 1.9 ± 0.06 × 10⁹ per stripping).

The objective of this study was to develop a superovulatory program based on synchronization of follicular waves with GnRH which could be applied regardless of the stage of the oestrous cycle. 36 heifers were subjected to this experiment and GnRH (Cystorelin, 200 µg) was applied between Days 0 and 7 (n = 15), 8 and 12 (n = 8) or 13 and 20 (n = 13) of the oestrous cycle. Four days after GnRH treatment, all follicles ≥ 6 mm of heifers (n) were either punctured (n = 21) or left intact (n = 15). All heifers were superstimulated from Day 6 to Day 10 after GnRH treatment with 320 mg Folltropin-V. In parallel, 21 heifers were superstimulated in a conventional manner (Days 8 to 12) and were used as controls. The homogeneity of follicular inventories among Stage-groups occurred within 4 days of GnRH treatment for follicles ≥ 7 mm but only 2 days after follicular puncture for follicles 4 to 6 mm. In response to the follicular puncture, the mean number of follicles 4 to 6 mm increased in heifers of the punctured group (P < 0.01). Following the superstimulation, the follicular (P < 0.01) and ovulatory (P < 0.01) responses were higher in the punctured group than in the nonpunctured group. The in vivo production of transferable embryos in the punctured group was similar to that of the nonpunctured group but it was lower (P < 0.01) than in heifers of the control group. In conclusion, results from the present study indicate that regardless of the stage of the oestrous cycle, the homogeneity of follicular inventories following the follicular synchronization is obtained using GnRH treatment and follicular puncture. The in vivo production of embryos was severely compromised in the present study with heifers. Causes of such reduction in the in vivo production of embryos are still unknown.

The aim of the experiment was to determine the impact of sorting on the growth, survival, and cannibalism of pikeperch larvae during intensive culture in recirculation systems. Larvae aged 48 days post-hatch (DPH) were reared in three groups - small specimens (group S - average body weight 40 mg), large specimens (group L - average body weight 76 mg), and unsorted ones (group U - average body weight 55 mg). After three weeks of rearing, there were no statistically significant differences in specific growth rates among the groups. However, increases in biomass were higher in the sorted groups. Survival exceeded 50% in the sorted groups and 39% in group U. Higher cannibalism was noted in group U than in the sorted groups. Significant differences among the sorted groups were observed in cannibalism, which was higher in group L, and in natural and manipulation losses, which were higher in group S (P < 0.05). During the first two weeks of rearing, the lowest cannibalism rates were observed in group S, the difference between groups S and U was statistically significant (P < 0.05). The results of the experiment indicate that the sorting of pikeperch larvae has a positive impact on the survival rate, however, it has no impact on growth during their rearing in the RAS.

Summerling (six-month old) noble crayfish fed two forms of freshly decapsulated (FD) Artemia cysts more than tripled their weight during a 75-day experiment under controlled conditions. Final survival rates were at the level of 90%. Feeding commercially available industrially decapsulated cysts resulted in both poor growth and reduced survival (22.2%). Therefore FD Artemia cysts may be an effective diet for crayfish culture, but dehydrated industrially decapsulated (DID) cysts should be used with caution to avoid products of low quality. That should be considered especially in slow feeders such as crayfish because of leaching of nutrients from DID cysts. Costs of the processing of freshly decapsulated cysts are discussed.

A study was conducted (I) to determine rumen degradability (in sacco) of dry matter (DM) and neutral detergent fibre (NDF) of the most important grass species grown in the Czech Republic, (II) to compare grass species (n = 5) according to calculated degradation parameters, and (III) to establish prediction equations for degradation parameters from chemical composition. Forty samples of the most important grass species (Dactylis glomerata, Phleum pratense, Lolium perenne, Festuca arundinacea, Felina hybrid) were harvested in 2004 and 2005 and analyzed for chemical composition, and DM and NDF in sacco degradability. Results from the in sacco method were used to calculate DM and NDF degradation parameters. Linear and stepwise multiple regression analyses were used to develop prediction equations for DM and NDF degradation parameters from nutrient concentrations. The highest DM and NDF degradation parameters were found for Lolium perenne. DM and NDF rumen degradation parameters were successfully predicted from chemical composition, with a single predictor adequate for most parameters. For all parameters R²-values increased with addition of more predictors into regression equations. Effective degradability (ED) of DM calculated at a rumen outflow rate (k) of 0.05 h^-1 was the best predicted by NDF (R² = 0.878), and ED of NDF at k = 0.02 h^-1 by crude protein (CP) (R² = 0.653).

The effect of three housing systems (conventional cages, enriched cages and litter) on egg quality parameters was evaluated in two experiments with four brown laying strains ISA Brown, Hisex Brown, Bovans Brown and Moravia BSL. During 40 weeks of lay the total number of 7200 eggs was produced and analysed for egg weight, egg component weight and eggshell quality indicators. In 60 eggs, pore density in the small-end, large-end and equatorial areas was determined. Significant interactions between genotype and housing were found out in egg weight (P ≤ 0.001), yolk and albumen weight (P ≤ 0.001) and yolk colour (P ≤ 0.001). Haugh units were the highest in eggs laid in cages and the lowest in the ISA Brown strain. Eggshell quality indicators were affected more by genotype than by housing. The interaction between genotype and housing was not significant for eggshell thickness but it was significant for eggshell weight and strength. Although eggshell thickness was lower in eggs produced in cages, eggshell strength was higher. A significant negative correlation was found out between pore density and housing system. Results of the study suggest that the ability of a strain to produce eggs of high quality in a particular housing system should be considered, even within brown strains.

The goal of this study was to compare the growing degree-days (GDD) and predictive equations for alfalfa quality (PEAQ) for the prediction of lucerne quality and to test their accuracy and suitability in the first cut period in Central Bohemia. Several additional stand parameters were verified in order to increase the accuracy of the quality estimate under these environmental conditions. In 2004-2007, the measurement and sampling were repeatedly realized from the late vegetative to the early bloom stage in six replications. For the GDD model across the years, the obtained R² for NDF, ADF and CP were 0.40, 0.57 and 0.65, respectively. It seems that the forage quality response to accumulated GDD was related to the stand development and it could be the reason for low R² across all the years. For the PEAQ model, R² were 0.62, 0.92, and 0.85, respectively. Similarly like in the GDD model, the effect of stand development across the years on changes in the slopes of equations was observed. The accuracy of the model combination was not higher in comparison with the PEAQ model. The count of stems per plant, density of stems per m², dry matter yield and average stem weight improved the NDF content prediction within a four-year period. In these models, variables which represent the stand development should be taken into account.

The aim of this study was to determine the impact of the length of calf sucking milk from its own mother on calf growth at the age of 3 months and milk yield of mothers. We tested a hypothesis that the nursing of calves by their own mothers increases the body weight of calves and decreases the milk production. 50 Holstein primiparous cows and their calves were divided into three groups according to the sucking length of calves: 7 days (A), 14 days (B) and 21 days (C). All calves suckled mother's colostrum and milk while mothers were milked twice per day. After weaning from mother calves were kept in individual hutches until 56 days of life, and then in group housing pens. In the period from birth to weaning the calves of group A reached the lowest and the calves of group C the highest daily gains (0.35 kg, 0.46 kg, 0.54 kg; P < 0.01). The lowest gain was recorded in animals of group A (0.55 kg) and the highest gain was reached by calves of group C (0.74 kg) for the period from birth to three months of age. For the first 305 days of lactation cows of group A produced insignificantly more milk than group C (7356.5 kg, 6779.2 kg, 6663.9 kg). A significant difference in milk production was recorded only during the first seven months of lactation (5494.5 kg, 5041.9 kg, and 4872.3 kg; P < 0.05). The long stay of calves with their mothers influences the growth of calves positively, but the milk production of mothers may decrease. Therefore, the stay of calves with the dam within 21 days after birth is not recommended for high-yielding dairy cows.

The circadian rhythm of body core and surface temperature in 10 Comisana sheep kept under a natural photoperiod (06:30/19:00) was evaluated. Every 3 h for 24 consecutive hours rectal temperature (RT) and foot temperature were recorded. Particularly, foot temperature was recorded by infrared thermography, an ideal technique for evaluating the temperature not only at one point but also at the eight points as follows: in the right front of the interdigital area (FA1), in the left front of the interdigital area (FA2), in the right rear of the interdigital area (RA1), in the left rear of the interdigital area (RA2), in the right front of the interdigital line (FL1), in the left front of the interdigital line (FL2), in the right rear of the interdigital line (RL1) and in the left rear of the interdigital line (RL2). Two-way repeated measures ANOVA using SPSS, followed by Scheffé's test, showed a significant effect of the time of day and side of temperature collection (P < 0.05) on temperature values. The single cosinor procedure showed a daily rhythmicity of RT and foot temperature in all tested sides. The circadian oscillations of RT reflected the familiar circadian patterns of endogenous sources and the results of foot temperatures supported the idea that the daily rhythm was, at least in part, influenced by variation in the blood flow to the extremities. The infrared thermography providing more information on the development of disturbances in the peripheral circulation may be used with an advantage in occupational health examinations and in special clinical work.

The present study was carried out on 68 barrows equally distributed into two different feeding groups (intensive and restricted). MR tomography was used to obtain data needed for the calculation of optimal slaughter weight. Growth analyses and predictions were performed using an asymmetric S-function. The differences between the predicted and real time needed to achieve 100 kg live weight calculated for the two feeding groups of pigs were not statistically significant. The prediction was fairly accurate in 88% of the cases for the intensive group and 79% of the cases for the restrictively fed pigs. The point of muscle growth saturation (t_C = 51.31 dm³) calculated for pigs from the intensive group occurred at 164 days of age. Restrictively fed pigs reached this point after 167 days. It was calculated that at 164 days of age intensively fed pigs reached about 126 kg; the pigs from the restricted group reached about 112 kg at 167 days. These weights can be regarded as optimal slaughter weights for pigs from the present study in the sense of maximum utilisation of muscle growth. Since both groups of pigs reach the same muscle volume of 51 dm³ at the estimated times, the difference in live weights can be attributed to the volume of fat. This makes the intensive system of feeding undesirable in economical pig production. It is concluded that the obtained parameters of the asymmetric S-function can be used for the growth analysis of other pigs, assuming that they are of the same genetic background and reared in the same conditions. It is suggested that the carcass values of pigs slaughtered at optimum live weights proposed here should be compared with the values of pigs slaughtered at other live weights in order to decide between maximum utilisation of muscle growth or achieving the most desirable lean percentage in carcass.

The purpose of this study was to analyse the influence of different external air temperature on changes in the air temperature of housing environment in the farrowing house for sows and consequent changes in selected parameters of performance in purebred Landrace sows and gilts. Raw data were analysed for 236 litters. The litters were born from October 2004 to March 2006. Air temperature in the farrowing house was monitored in the sow's living zone and was closely related to changes in external air temperature (P < 0.01). At the optimal internal temperatures for lactating sows (16-22°C) during mild winter the lowest incidence of stillbirths (9.92%) was detected, whereas at high internal temperatures (above 28°C) the incidence of stillbirths was 11.32% (P < 0.01). The lowest average daily weight gain was recorded during mild winter (P < 0.05).

The aim of the present paper was to study the effect of shearing on some haematochemical parameters in ewes. Forty Valle del Belice ewes, clinically healthy and well-fed, were divided into two groups of twenty subjects each. Twenty ewes were let unshorn as a control group (Group A) and twenty ewes were shorn (Group B). After the blood collection by means of jugular venipuncture, some haematochemical parameters were assessed for each subject in the following experimental conditions: before shearing, 1^st, 15^th, 30^th, 45^th, 60 and 75^th day after shearing. We studied the course of the following haematochemical parameters: glucose, β-hydroxybutyrate, NEFA, triglycerides, total cholesterol, total protein, urea and creatinine. Two-way repeated measures analysis of variance (ANOVA), followed by Bonferroni's test, was used to determine significant differences between the two groups in the studied parameters. The statistical analysis showed statistical differences (P < 0.05 was considered statistically significant) in β-hydroxybutyrate, NEFA, total protein and urea. Data analysis of variance showed a significant effect of time, with P < 0.0001, on all studied parameters. These results suggest that shearing induces adaptive metabolic responses in the ewes and exposure to elevated ambient temperature induces modifications of some haematochemical parameters.

The aim of this study was to determine the influence of MHS-genotype and feeding regime on the growth and development of muscle and fatty tissue in the whole body as well as in hams of hybrid pigs. The experiment was carried out on 72 barrows that were divided into 4 groups regarding the MHS-genotype (NN and Nn) and feeding regime (standard and intensive). Data necessary to determine the volume of examined tissues were obtained by means of magnetic resonance tomography. During the fattening period there were no statistically significant differences between pig groups with respect to total lean content of the body although the feeding regime effect in the finishing fattening phase was on the margin of statistical significance (P = 0.057). Differences between investigated groups with respect to the lean content in hams were not significant either. Results of this research lead to a conclusion that different feeding regimes and MHS genetic status of pigs do not have a significant influence on the growth of muscle and fatty tissue in hams.

The concentration (c) of free fatty acids (FFAs) in milk is an indicator of dairy cow nutrition, milk straining, its bacterial contamination and storage quality. High FFA concentrations (cs) caused by lipolysis can damage the quality properties of milk products. Therefore the FFA content is introduced thanks to an increase in the efficiency of modern analytical methods as a milk quality indicator and as an indicator for its price as well. The goal of this paper was to analyse the FFA relations to the other milk quality indicators. The data set (n = 11 586) was evaluated by regression methods. In November and December the respective FFA means were 0.614 ± 0.458 and 0.835 ± 0.491 mmol/100 g with a relatively high variability of 74.6 and 58.8%. The frequency of unsatisfactory FFA values (> 1.3) was 7.51 and 13.93%. Casein content (r = -0.17; P < 0.01) and crude protein content (r = -0.12; P < 0.01) were related more closely with FFA c. The FFAs can increase by 0.066 mmol/100 g with casein decrease by 0.10%. The FFAs in milk fat can slightly increase by the supply of energy to dairy cows (protein and casein decrease) and rise with the deteriorating health state of mammary gland (lactose, r = -0.14; P < 0.01) as well. The somatic cell count correlated with FFAs more weakly (r = 0.07; P < 0.05), similarly like the total mesophilic bacteria count (r = 0.11; P < 0.01), relatively more closely the psychrotrophic bacteria count (r = 0.27; P < 0.05). The deterioration of almost all hygienic indicators signified an FFA c increase. The urea content correlated with FFAs weakly (r = -0.08; P < 0.05) and the fat content imperceptibly as a component of similar substance like FFAs. The mechanical milk stress led to FFA liberation from fat esters proportionally to the intervention intensity (P < 0.001). Even a relatively small mechanical stress caused by mixing comparable to the current milking technology, milk transport and storage increased the FFA c of milk fat from 1.11 ± 0.19 to 1.80 ± 0.40 mmol/100 g (P < 0.05). The highest experimental stress up to 6.88 ± 0.55 mmol/100 g (P < 0.001).

The objective of this study was to confirm the relationship among body condition score at the time around parturition, milk yield in subsequent lactation, reproductive efficiency and BCS development in Czech Fleckvieh dairy cows. The BCS and milk yield were measured once a month and the cows were divided into groups according to their BCS before and after calving. Next, data from the database of cattle reproduction of the Czech Fleckvieh herd book were used. The dataset was analyzed by multifactorial analysis of variance using procedures COOR and GLM of the statistical program SAS. Cows with lower BCS in the 1^st month after calving showed an increase in both milk yield and fat and protein corrected milk (FPCM) yield. No significant relationship was found between the BCS level before calving and subsequent milk yield. The body condition level in the last month before parturition influenced its subsequent decrease in the first phase of lactation. The group of cows with the highest BCS level before calving retained a high BCS level in the first five months of lactation. Adequately, the group of cows with the lowest BCS in the first month of lactation had the lowest BCS in the next four months. BCS before calving was not related to reproduction indicators, but the significant effect of BCS in the 1^st month after calving on the length of calving to the first service interval was confirmed. The group of cows with BCS > 3.5 in the 1^st month after calving had the most favourable reproduction indicators, also when the milk yield level was taken into account.

The objective of this study was to analyze the effects of non-genetic factors affecting calving difficulty in the Holstein population of the Czech Republic for subsequent compilation of the model for genetic evaluation as well as for herd management practice. Calving difficulty recorded in 1997-2006 was assessed in three categories: 1 = normal, 2 = hard pull, 3 = complicated. The original observations were transformed to an underlying normal scale. A data set containing 409 255 records was analysed by a linear model with fixed effects of season, parity of dam, sex of calf and Holstein gene proportion. All these effects were significant, and their appropriate categorization was considered. Analyses of additional factors such as gestation length, age at first calving and preceding calving interval were performed. The results revealed that gestation length was in a non-linear relationship with calving difficulty. A higher risk of difficult calving was associated with short or long gestation and with a prolonged preceding calving interval in multiparous cows. Calving difficulty should be adjusted for these factors. A decreased risk of difficult calving could be achieved by an altering of calving interval and age at first calving as a management tool.

The aim of this study was to evaluate the effects of recombinant human inhibin A, recombinant human activin A and desteroidized ovarian extract on LH secretion in vitro and in vivo in female common carp during different stages of reproductive cycle. Inhibin stimulated spontaneous as well as GnRH-stimulated LH release in vivo in fish during gonadal recrudescence. This hormone did not have an influence on spontaneous LH secretion in the periovulatory period, but had a slightly inhibitory effect on GnRH-stimulated LH release in this stage of gonad maturity. Activin decreased spontaneous LH secretion during gonadal recrudescence and increased LH secretion before ovulation, having no effects on GnRH-stimulated LH release during both stages of gonad maturity. The desteroidized ovarian extract failed to modify spontaneous LH secretion, but decreased GnRH-stimulated LH release during recrudescence and especially before ovulation. It is to conclude that these data suggest the differential role of inhibin/activin as substances in the regulation of LH secretion in common carp females.

Twenty-four Czech dairy farms were visited to record lameness prevalence and to identify factors associated with high lameness prevalence at the farm level and/or increased lameness risk at the level of individual cows. All cows were checked for lameness and forty cows per farm were examined for overgrown claws, body dirtiness and skin lesions. The farm environment was scored between 1 (excellent) to 5 (very poor) in three different aspects: floor slipperiness, cow care quality, and housing quality. Data on hoof trimming schedules were obtained from farm managers. Lameness prevalence on farms was in a wide range from 6% to 42% (median 22%). At the farm level, floor slipperiness and poor animal care were associated with high lameness prevalence (Spearman correlations, P < 0.05), and the proportion of cows with overgrown claws tended to be associated with it (P < 0.10). The reported time schedules of hoof trimming (continuous trimming applied or not; and time elapsed since the whole herd was trimmed) were unrelated to either the prevalence of overgrown claws or the prevalence of lameness. Within farms, cows with overgrown claws and dirty cows were at an increased risk of being lame (multiple logistic regression, P < 0.05) and cows with skin lesions tended to be more lame (P < 0.10). The risk of lameness had an inverted U-shape dependence on age (P < 0.05), with cows at 7-8 years of age being the most endangered by lameness. We conclude that there is a large potential for lameness reduction on some Czech dairy farms through improving the cow care and reducing floor slipperiness, and that within farms, cows with overgrown claws and also dirty cows and cows with skin lesions should be given special attention since they are more likely to get lame.

The quantification of emissions of greenhouse gases from human activities is of prime importance for determining the importance of their effect on the environment. The aim of this study was to test a hypothesis that the interior concentration and emission of carbon dioxide in chicken housing is impacted by the age of animals and season of fattening period. Carbon dioxide (CO₂) concentrations and emissions were assessed over six fattening periods in total. The major part of CO₂ seemed to have its origin in bird respiration with assumed production of approx. 147 kg of CO2/h. CO₂ emission was most affected by chickens towards the end of the grow-out period (P < 0.001) taking dominance over the process of natural gas burning by heaters. The mean CO₂ emission from the chicken house ranged between 120 and 247 kg/h in the first quarter of periods and between 325 and 459 kg/h in the last ones. The heaters could be theoretically a possible source of approx. 39 kg each hour if they worked continuously. CO₂ emissions were considerably more affected by ventilation rate (P < 0.001) than by CO₂ concentration in the indoor air.

Cholecystokinin (CCK) affects the intestinal motility but in ruminants the question has not been entirely explored. The aim of this study was to examine the precise effects of CCK-octapeptide (CCK-OP)and its amphibian analogue, cerulein, on duodenal motor activity in unfasted rams in the course of chronic experiments. Five rams underwent the implantation of a strain gauge force transducer to the duodenal wall, and - additionally - the bipolar platinum electrodes to the duodenal bulb, distal duodenum, near the strain gauge force transducer, and proximal jejunum. During continuous motor recordings, 0.15M NaCl or CCK peptides were administrated intravenously. Injections of CCK-OP at doses of 20 (over 30 s), 200 (over 30 or 60 s), and 2 000 (over 30, 60, or 120 s) ng/kg of body weight and injections of cerulein at doses of 1, 10, or 100 ng/kg (given over the same periods) were each administered in the course of duodenal phase 1, 2a, or 2b of the migrating motor complex (MMC), i.e. 5 min after the onset of each phase. Injections of the smallest doses of CCK peptides exerted a slight and mostly insignificant effect on the duodenal areas under contraction (AUC). In the duodenum, the moderate doses of the hormones evoked short stimulatory effects followed by longer inhibitory biphasic effects on AUC. These effects were inversely related to the duration of the hormone injection. It is concluded that CCK evokes stimulatory and inhibitory (biphasic) physiological effects on duodenal motility in sheep.

The effect of season and parity order on doe fertility and rabbit growth was evaluated. Two hundred and fifty Hyplus® does were divided into five groups according to kindling, each in a given season of the year (September, December, February, April and June). Another five groups were separated by parity order (from the first to the fifth kindling). After weaning, each group of rabbits was fed until 77 days of age. The season of the year significantly affected service number of pregnancy, litter size, litter weight at birth, litter weight at 21 days, litter size at weaning as well as live weight at 77 days. Parity order affected service number of pregnancy and litter weight at 21 days in a more limited way. Significant interactions of season and parity order were determined in service number of pregnancy, with the highest values occurring in December (2.2, P ≤ 0.010) and February (1.9, P ≤ 0.010) at the second kindling. Litter size was the largest in December and at the fifth kindling. Significant interactions (P ≤ 0.015) were also found in litter weight at 21 days, whereby litter weight had increased by the third kindling. However, the highest litter weight was reported after the fourth kindling in December.

Eleven microsatellite loci (TGLA227, BM2113, TGLA53, ETH10, SPS115, TGLA126, TGLA122, INRA023, ETH3, ETH225, BM1824) were evaluated for their use in paternity testing in the Yugoslav Pied cattle (YU Simmental cattle) population in Serbia. A total of 40 animals were tested. At the 11 tested loci, a total of 91 alleles were detected. The mean number of alleles per locus was 8.273. Polymorphism information content (PIC) values ranged from 0.58 to 0.88 with the mean value of 0.72. The most informative loci were: TGLA53 (14 alleles, PIC = 0.88), TGLA227 (11 alleles, PIC = 0.82), INRA023 (11 alleles, PIC = 0.86), BM2113 (9 alleles, PIC = 0.80). Combined power of discrimination (CPD) for the 11 microsatellite loci was 0.999. The results of the present study confirm that the analysed set of 11 microsatellite markers recommended by ISAG is suitable for paternity testing in Yugoslav Pied cattle in Serbia.

This paper compares two different housing systems for laying hens producing table eggs, namely a conventional cage system and an aviary, during three summer months, starting from the 20^th week of the production cycle. Research was focused on airborne bacteria, fungi and dust levels and on the bacterial eggshell contamination. Levels of airborne bacteria determined in the aviary system were many times higher and ranged from 6.2 × 10⁴ CFU/m³ to 8.9 × 104 CFU/m3, and the levels of airborne fungi ranged from 1.6 × 10⁴ to 1.9 × 104 CFU/m³, while the levels of airborne bacteria and fungi determined in the conventional cage system ranged from 1.6 × 10⁴ to 2.5 × 10⁴ CFU/m3 and from 0.8 × 10⁴ to 1.3 × 10⁴ CFU/m³, respectively. Microbial air contamination was associated with eggshell contamination, with the levels in the aviary ranging from 5.4 × 10³ to 9.6 × 103 CFU/eggshell and those in the conventional cage system ranging from 2.3 × 10³ to 3.6 × 10³ CFU/eggshell. Airborne dust levels in the aviary and conventional cage system ranged from 3.2 to 4.6 mg/m³ and from 0.7 to 1.2 mg/m³, respectively. From the aspect of animal welfare and behavioural requirements, alternative systems, i.e. aviaries, appear more acceptable; however, they are not satisfactory from hygienic aspects because of a higher content of airborne pollutants which can represent a greater risk of horizontal contamination of the egg content.

Estimates of the effects influencing the economics of pig production are of primary importance for breeders. For this purpose, costs, revenues and profitability were determined on the basis of individual parameters of the efficiency of tested pigs and of average commodity prices. The calculation was the result of the efficiency of actual animals and of the average and simulated prices of inputs received by producers in large-scale production operations. 136 animals, 64 of crossbred combinations (LWs × D) × (LW_D × L) and 72 of PN × (LW_D × L) were used. The total cost of 1 pig represented the costs per weaned piglet, feed and other costs; the revenues represented the actual price of a pig at slaughter. Multivariable hierarchical models were constructed to assess the relationships between the following factors: crossbred combination, nutrition and sex, ADG, number of piglets bred, CFM price and carcass price with the outcome variables: costs, revenues and profitability. The results demonstrated that the total cost of fattening pig is considerably influenced by the price of a piglet and feed, not by the price of the carcass and the growth intensity. There was no proof of a relationship between the price of a pig and reproduction and/or the price of feed. Profitability is significantly influenced by the reproduction rate, price of feed, growth intensity and revenues. The results also showed that the intensity of nutrition and the sex considerably influence the total cost of 1 fattened pig, which represents an increase in the total cost by 3.80 € in the application of ad libitum feeding techniques, and 5.39 €/pc in the fattening of barrows. The choice of a suitable combination represents a decrease in the total cost by 1.49% and an increase in revenues by 2.93%. Profitability is significantly associated with the intensity of nutrition, sex and breed. With unrestricted feeding it is reduced by 4.1%, for barrows by 6.6%, and in the use of four-breed combinations of crossbreds it increases by 4.13%.

The objective of this study was to assess the sperm membrane integrity in extended boar semen during storage time using specific spectrum laboratory methods. Boar semen was diluted with the long-term liquid commercial extenders Androhep (A), Androstar (AS), Androstar plus (AS⁺), LD and M III and was stored up to 96 h. The sperm membrane integrity was evaluated by motility, viable spermatozoa, short hypoosmotic swelling test (sHOST) and by the activity of the enzyme aspartate aminotransferase (AST). Negative changes in the quality of sperm membrane in relation to storage time were observed after 48 h for sHOST, after 72 h for viable spermatozoa and after 72 h for motility. The percentage of viable spermatozoa was decreased by 0.27% each hour. A statistically significant difference between extenders A and LD was observed in sHOST after 72 h and 96 h storage (P < 0.05). The AST activity did not show any statistically significant differences in extenders and in storage time. In overall assessment Androhep was the best of the tested extenders, followed by AS, AS⁺, M III and LD in terms of motility, viable spermatozoa and sHOST. The correlations among laboratory methods were highly significant (P < 0.001). In conclusion, the results documented that the sperm membrane integrity was statistically significantly affected by extenders and storage time (P < 0.001). Boar semen quality was the best in extender A. sHOST is a very sensitive and relatively simple method for the assessment of sperm membrane integrity in diluted semen.