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The effect of genotype and the location of sampling on the mineral content of wool
157-160Views:712Mineral supplementation is very important in high producing farm animals. The estimation of exact mineral intake is very difficult in forage eating animals, like sheep. Accessing of long term mineral status seems to be possible using wool mineral analysis. However several factors can affect the results. Therefore, the aim of this study was to test the effect of breed and sampling location on the mineral content of sheep wool. 20 Dorper and 20 Tsigai sheep were chosen from the same farm. Samples were obtained from 3 locations (withers, side and quarter) and tested for 8 elements: Ca, Mg, Na, Co, Cu, P, S, Se , Zn. The samples were cleaned with ethyl alcohol from organic contamination, then after adding nitric acid were mineral analized using ultrasonic cleaning unit. The samples were analysed with ICP-OES (Perkin-Elmer, Optima 3300 DV). Statistical analyses were carried out by GLM procedure of SAS statistical analyses software. Differences between means were checked with Tukey-test. Significant breed differences were detected in the case of Mg, Na, S, Se in spite of the same feeding regime. The wool mineral content were within the reference range. The sampling location had no effect on the mineral content of wool.
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Az évszak és az azonos évszakban történt ismételt mintavételek hatása holstein tenyészbikák ejakulátumának minőségi- és mennyiségi jellemzőire
33-37Views:247This study was carried out at the Hungarian National Artificial Insemination Centre in order to evaluate the seasonal effects on the quantitative and qualitative parameters of sperm production using sperm analyser equipment. The volume of ejaculate (VE), percentage of living sperm (PLS), spermatozoa concentration (SC), motility score (MC), percentage of motile spermatozoa (PMS), speed of movement of sperm cells (SMS) and the percentage of sperm cells moving straightforward (PSMS) were collected and observed in three seasons (summer, autumn, winter) in Holstein-Friesian breeding bulls (n = 15). The sperm collection was done for three successive weeks in every season on the same day (summer: n = 41, autumn: n=39, winter: n = 42, altogether: n = 122). The same sperm samples were measured by sperm analyser equipment (HTM version 7.0, Danvers) for PMS, SMS and PSMS. The seasonal and the number of sperm collection effects were confirmed on semen characteristics by multiple analysis of variance (two ways MANOVA, Type III) using the program package of STATISTICA 4.5. The average values of VE were similar in the three seasons (summer: from 4.42 to 6.28 cm3, autumn: from 4.08 to 6.86 cm3, winter: from 5.43 to 5.71 cm3). The average values of the MC were similar in each of the three seasons (summer: from 3.66-4.00 M; autumn: from 3.66-3.77 M; winter: from 3.86-4.07 M). The summary of all effects for season (P<0.001), repeated sperm collections in the same season (P<0.05) and interaction of two traits (P<0.01) were established on the measured characteristics. The special effects (P<0.05) of a given season were calculated, excepting the VE and MC, on all of the measured characteristics. The special effect (P<0.01) of the repeated sperm collections in the same season was verified in only one case (SMS). It is not surprised at the interaction was established on the VE (P<0.001), PMS (P<0.05), and SMS (P<10.0). The results of present study suggest that seasonal effect on sperm quality of breeding bulls cannot be eliminated even at standard feeding and keeping conditions. Considering our results, we can recommend that the average values of three successive weeks in every season be used, to take advantage of seasonal effect on the quantitative and qualitative parameters of sperm production.
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Investigation of the effects of biggame-preserves on forests with different species composition
21-24Views:408Hungary is well known for its high level game management. In order to develop a concentrated and more profitable gamemanagement new game preserves were established in the last few years. According to the law, in the game-preserves the game bearing capacity is not the most important parameter, because in these areas the feeding is continuous. In practice it means that in gamepreserves we find a much higher density of games than in nature. This causes a relative big loading of the area (of the herbaceous and arboreal), where the game-preserves are located.
Our aim is to study the ecological and management issues of forest- and game resources. The scene of these work is a gamepreserves related to the Nyírerdő Corporation (Nyíregyháza). We made forest structure survey to determine the main stand-forming tree species in the area of the game preserves as well as to estimate the number of the measuring points. -
Occurence and spreading of box tree moth (Cydalima perspectalis Walker 1859) on the North-East region of Great Hungarian Plain
45-50Views:412Box tree moth shows (Cydalima perspectalis) rapid spread in Europe. In Hungary it appeared first near to the western border of the country in 2011. In the eastern part of Hungary the first specimen was caught in 2015 with blacklight trap. Here we summarize its distribution in northern part of the Alföld (Great Hungarian Plain) on the basis of blacklight, pheromone and feeding attractant traps. We publish five new distribution data from northern part (4 from Hungary, 1 from Transcarpathia) and two from southern part of the Alföld. Beyond that the flight of three generations was observed both in the year 2015 and 2016.
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Examinations connected with productive life in Hungarian Holstein Friesian populations
32-39Views:366In Hungary, an intensive dairy population has developed in the last few decades as the result of upgrading to Holstein-Friesian. Intensive milk production, adjusted with housing and feeding, unfavorably affected secondary traits. The number of days between two calvings has increased remarkably and productive lifetime has decreased drastically. In the interest of profitable milk production, it is important that cows should be able to stay in the herd as long as possible, in order to have great lifetime productivity.
The aim of this paper was to compare the production and pedigree of cows with eight or more lactations to cows which were culled after their first lactation.
It can be stated that cows with longer herd lives produced more milk in their first lactation than those which were culled after their first lactation. When analyzing the pedigree effect of sires, this could not be proven, although some bulls, mainly of Hungarian origin, appeared at a higher frequency. In the analysis of the effect of dams, it was found that many of the offspring of the cows with longer herd lives had similarly great lifetime productivity. Correlation between herdlife and milk production quantity traits was found to be mild or stronger (r>0,60), while according to our analysis, there is no correlation between herdlife and milk production quality traits. -
The effect of diet composition, a probiotic and a symbiotic treatment on the ileal microbiota composition of one-week-old broiler chickens
213-220Views:332A healthy microbiota present in the small intestine contributes significantly to small intestinal function, including digestion, nutrient absorption and health. The current study investigated the effects of a prebiotic, a probiotic and a symbiotic supplementation on ileal microbiota composition of broilers at 7 days of age. In a total of 574 male Ross 308 day-old chickens were divided into four groups using six replicate pens and 24 chickens per pen. A maise-soybean based control diet (C), a control diet supplemented with probiotics (Broilact; Br), a control diet supplemented with symbiotic (inulin, yeast, Bacillus subtilis; Sy) and a wheat based diet supplemented with wheat bran (W) were formulated. On day 7 of life, two chickens per pen were slaughtered and ileal chymus samples were collected. For microbiota analysis 16S rRNA (V3-V4 region) gene targeted Illumina MiSeq sequencing was used. Feeding all diets supplemented increased the diversity to varying degrees compared to the control (C) diet (p=0.006). As a conclusion, all supplementation substantially influenced ileal microbiota of broiler chickens at an early age. All these results could offer some information for the future study on the relationship between early intestinal microbiota and the compounds of the feed.
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A growth model to predict body weight and body composition of broilers
17-24Views:504Models predicting the nutrient partitioning and animal performance have been developed for decades. Nowadays, growth models are used in practical animal nutrition, and they have particular importance in precision livestock farming. The aim of the present study was to introduce a broiler model and to provide examples on model application. The model predicts protein and fat deposition as well as the body weight of an individual broiler chicken from digestible nutrient intake over time. Feed intake (FI) and the digestible nutrient content of the feed are inputs as well as some animal factors like: initial BW, feed intake at 1 and 2 kg of BW, precocity and mean protein deposition. The protein and energy metabolism is represented as in the classical nutrient partitioning models. The protein deposition (PD) is driven by digestible amino acid supply and is under “genetic control”, the so-called potential PD limits the actual PD if protein is oversupplied.
The authors discuss how the model can be used to simulate the animal response upon different scenarios. Examples are given to show that the diet might be limiting if some animal trait is changed. Applicability of the model has shown through running the model by using different feed strategies (three- vs five-phase-feeding) and variations with animal factors. In conclusion, growth models are useful tools to support decision making for defining the most suitable feeds used in a broiler farm. The model presented in this paper shows a high sensibility and flexibility to test different scenarios. By challenging the model with different inputs, the animal response in terms of changes in body weight and feed conversion can be understood more by studying the shift in deposition of chemical constituents. The examples provided in the present paper shows the benefit of using mathematical models and their applicability in precision nutrition. It can be concluded that the growth model helps to apply “from desired feed to desired food” concept.
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Ideas on the European stone fruit yellows – as an entomologist can see them
30-34Views:362The European stone fruit yellows (ESFY) is an important endemic disease in Europe which causes in both, the Mediterranean countries and Central Europe serious damage. Its pathogen is the ‘Candidatus Phytoplasma prunorum’. The treatment and healing of the diseased trees and plantations with chemicals do not promise success. Thus, prevention may be the only solution. The transmission and spread of the pathogen happen by infected propagation material (grafting) or a vector (the psyllid, Cacopsylla pruni). Mechanism of the pathogen’s transmission and population dynamics of the vector have been extensively investigated in several European countries, which may allow by the control of C. pruni even to hold back the disease. Diseased stone fruit trees and wild Prunus spp. as main host species play an important role in maintaining and spreading the pathogen. C. pruni collects the pathogen by feeding on these plants and it carries persistently ‘Ca. P prunorum’. Researchers in Hungary have been characterized the disease only in terms of plant pathology, but neither the significance of the vector nor the role of wild Prunus spp. have been studied. This summary intends to give clues to these researches, that not only axe and saw should be the instruments of national control, but knowing the role and population dynamics of the vector the stone fruit production should be more successful.
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Dynamics of alfalfa production in Hungary: Changes in harvested area, yield, and total production over 30 years (1990 – 2024)
163-169Views:475Alfalfa is a crucial forage crop in Hungary, contributing to sustaining livestock feed and soil fertility management. To assess the dynamics of alfalfa crop production in the country, this study examines the variations and patterns in harvested area, total production, arable land area, and average yield of alfalfa over the previous three decades (1990 to 2024). Our findings reveal fluctuating patterns, with periods of increase and decrease in all parameters under study. While certain years exhibit growth due to favourable climatic conditions and improved agricultural practices, others show declines, potentially influenced by economic factors, changes in crop demand due to a decline in livestock production, and unfavourable climatic conditions, particularly drought. The analysis highlights the complication of alfalfa production trends, underscoring the need for expanding land area and adaptive strategies in Hungarian forage crop management to enhance alfalfa crop production to sustain livestock’s feeding system.
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Statistical comparison of coverage data of disturbed habitats in the Hajdúság
171-178Views:180Between 2002 and 2006 we made the coenological survey of five disturbed habitats marked as grasslands. With our coenological examinations and the statistical analyses we wanted to make the detailed botanical survey of the given five habitats in order to verify that the maintenance of habitats amongst agricultural lands – and considered as less valuable – is of high importance and necessary from an environmental point of view, since these habitats are often living and feeding areas of many rare and/or protected plant- and animal species.
As a result of the statistical analyses we have pointed out that number of species in case of all the five habitats extreme fluctuation characterizes the statistical universe. As regards the
average of the coverage it is the highest in case of the third habitat (degraded Puccinellia grassland), and the coefficient of variation shows homogenity as well. In examining the Shannon-value the average is the highest in case of the second habitat (Alopecurus meadow), and the statistical dispersion is the smallest. The coefficient of variation shows medium variability. The median of evenness is the lower in case of the third habitat (degraded
Puccinellia meadow) and the statistical is the highest here as well.
We have done the Hierarchical and the K-Means Cluster Analyses for the 21 plant associations of the five habitats. Both cluster analyses put the same associations into the same cluster, so
one can state that the associations in each cluster are different from the associations of the other ones according to the coverage data of the plant families. -
Evaluation of the blood product characteristics of meat meal and hemoglobin with non-invasive methods in the VISNIR wavelength
49-56Views:630The separate collection of poultry slaughterhouse trimmings and blood is partially solved in Hungary. Only properly prepared animal by-products, protein meals can be utilized as animal feed additive. However, different protein meals are appropriate for feeding different animal species. That is the reason why it is important to avoid accidental cross contamination of the products. Meat and blood meal produced on the same technological line, therefore mixing of the products can happen in various proportions during the shift of production.
Thus the aim of this study is to develop a spectral method which will allow to estimate the ratio of meat and blood protein meal in the final product. During the test the products were mixed in different proportions and were examined by the spectral method. Measurements were conducted with AvaSpec 2048 spectrometer in visible (VIS) and in near infrared (NIR) wavelength range (400–1000 nm) to define the spectral differentiation of the different meal products. Significant difference can be detected in spectral reflectance between the meat and blood product in the VIS-NIR range. The blood product has a characteristic spectral property: in the range of 600 and 735 nm reflectance values are increasing following a sigmoid curve. This property is not observed in the case of meat meal: close to linear rising is detected. Effective protein rate and purity detection could be made by Blood Product Sensitive Mixing Index (BPSMI – R930/R600), and by the calculation of inflection point in 600–735 nm.
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Industrial Utilization of Grasses
131-134Views:159The Agricultural Research and Development Institute P.U.C., Szarvas – realizing the importance of using the biomass in a number of ways – was one of the first in Europe, who began the breeding of grasses suitable for industrial utilization. The possible areas of using the energygrass – which could be called industrial grass – are the following:
– Energetical use
– Paper industry use
– Utilization as an industrial fibrematerial
– Use for feeding
The aim of the breeding programme: developing the kinds of grass, which yields big drymaterial mass and suitable for industrial utilization. These kind of grass, taking soil-utilization, economicality and environmental protection, offer and ensure new marketing perspectives and employment facilities for the disadvantageous areas. -
Surface polishing method application to reduce micotoxin content of mill wheat
339-342Views:266The fungi causing the infection and most of the harmful toxins they produce are concentrated in the bran of the grain, thus the intensive surface cleaning, the so-called debranning operation could allow the reduction of contamination in the milling technology. The essence of the PeriTec technology – originally developed by SATAKE, a Japanese company, to clean rice – is that it gradually removes the bran layers of the grain by mechanical means before further processing. We modeled the PeriTec technology with a laboratory size, batch-operating, horizontal debranning machine by SATAKE. The flour, milled grain after grinding 40 sec, the initial toxin content was only a small proportion (~15–20%) measured. The results showed that below the limit of DON toxin contaminated wheat (DON: 1.15 mg kg-1) during the grinding surface of the detached bran toxin contamination shows a very high (6.16 mg kg-1). The 40 seconds debranning before grinding shows lower DON toxin content than without debranning. So it is importance before the grinding. The toxin contamination of the bran fractions is significantly reduced, which is importance to the feeding point. As a result of debranning, the toxin content of the grinding fractions decreased, which justifies that that PeriTec method is suitable for the reduction of toxin contamination.
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Examination of feral pigeon populations at animal breeding farms
52-56Views:347In the course of our examination, we assessed biometric data that determine gender, we evaluated sexual activity, measured the nourishment and necropsies of two feral pigeon populations feeding and nesting at animal breeding farms. The changes in the body weight of the different genders were significant on both farms (p<0.05).
The body weight and the crop volume of the birds were not significantly different at the examined farms.
On both farms, the elemental food source of the birds was the fodder and corn kernels given to cattle, and was supplemented by that of the pigeons living at the Debrecen farm with food from surrounding farms and with other seeds (pea, millet, rye).
By the examination of the genitals, the birds collected from the Nyírbátor farm showed sexual activity from the beginning of spring, and in the summertime decreasing activity is characteristic, while the pigeons from the Debrecen farm are only active from the summer months. In the course of the examinations in the Veterinary Institute of Debrecen, the birds proved to be free of parasites and the results of the Newcastle disease analysis were negative as well. The bacteriologic analyses showed a different proportion of E.coli, Pasteurella multicoda, haemolysing Staphylococcus bacteria at the two cattle farms. During the examinations for the statement of Salmonellas, this causative agent was stated only in case of birds that spend nights and nested in the town, which allude to human origin. We demonstrated Eimeria oocysts during the parasitological examination of the fecal samples in 5 cases at the Debrecen, and in 1 case at the Nyírbátor farm. -
Risk effects of the spread route of mycotoxins
90-95Views:501In Hungary the mycotoxin is a great problem, because there are many natural toxins in wheat and maize. These cereals can be found on
considerable proportion of the country’s sowing area, and they are deterministic food for the population. The direct human and animal
utilization of the contaminated cereals mean a serious risk in the food chain. In Hungary’s climate the soil is contaminated with pathogen
moulds, particularly Fusarium species, which increase by respective temperature and moisture content in cereals. The Fusarium can
decrease the quality of the wheat in different ways: decrease the germination capability and cause visible discoloration and appearance of
mould, reduces the dry material and nutrient content of the grain. From the toxins produced by the Fusarium genus, the trichotecene (T-2,
HT-2, deoxinivalenol, nivalenol, diacetoxyscxirpenol, Fusarenon-X) and the estrogenic zearalenon (F-2) are the most common in Hungary.
The fumonisins (FB1, FB2, FB3) first identified in 1988, relatively newly discovered, are also important. Major proportion of mycotoxins in a
healthy organization is metabolized by the enzyme system of liver and intestinal bacteria. The toxicity is reduced or even leaves off.
However, more toxic and biologically active compounds can be formed. For the reduction of mycotoxin-contamination several possibilities
are available in the case of storage, processing and feeding. -
The variation of breast milk composition during the lactation stage for mothers from the Csík region
93-98Views:295The aim of our research was the examination of breast-milk composition from mothers living in the Csík region and to follow their milk composition variations during lactation. In this article we present the results obtained from three mothers, paying particular attention to essential components. The breast milk samples were collected from healthy mothers with similar habits and age. The milk samples were collected with a hand pump at the
same time after the feeding. The sampling period was from day 5 to the 14th weeks of lactation. The nutrition of mothers was recorded on a questionnaire, completed by the mothers themselves. Comparing our experimental results with data in the literature it was concluded that the milk protein content was very similar to the milk of mothers from other European countries, and is decreased during lactation.
The total saturated fatty acid content was lower, but the palmitic acid content was slightly higher. Regarding the essential fatty acid composition the linoleic- and the arachidonic acid contents were appropriate from a nutritional point of view. The linolenic acid was present in lower amounts, but the docosahexanoic acid was almost undetectable.
The iron and manganese contents were in good agreemen with published results, but the zinc content of the breast milk was lower and its copper content was higher. These differences in milk composition can be explained by the different nutritional habits of our subjects. -
Evaluation of Origin and Conformation of Excellent Cows with Long Productive Lives
13-17Views:332In the last few decades a new intensive milking stock has developed as a result of breed-converter crossing in Hungary. Beside this reproduction biology of the population was affected adversely by the keeping-, and feeding technology. Serviceable lifetime has shortened and service period has lenghtened. Whereas profitable milk production needs cows with longer productive life, larger life-time production. In our work we analysed the productivity-, and reputation parameters of the 200 highest lifetime-productivity cows of Hungary. We found that inheritance has not got important role in the serviceable lifetime. Adaptability and good constitution of Holstein-friesian is proved by the fact that cows with large life-time production are reared in large plants, some of them in large stocks, industrial environment. We found during the analysis of reputation parameters that these prominent cows mostly have deeper body, higher dairy form, higher rear udder, smaller foot angle. We found some weak connection between the milk production and the reputation. Loose correlations between useful material content and some linear traits were found.
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Effect of floor type and bedding system on sows lifespan
155-160Views:306The paper studies two nucleus pig farms in the Great Plain region of Hungary which have same management, same feeding system but different breeding technology (Farm A had solid floor with straw and Farm B had slatted floor without straw). The genetics of sows were crossbred Dutch Large White and Dutch Landrace. The comparative examination was based on the causes of culling according to the different floor type. To the analysis of culling reasons was applied the methods of survival analysis.
In the analysis there were used the Kaplan-Meier method and the Cox Proportional Hazard model to the estimate the difference between the farms. The results of survival analysis showed significant difference (p<0.05) between the lifespan of sows that caused the difference between the survival probabilities of sows culled due to lameness. Furthermore there was showed that the sows kept on solid floor with straw have stayed in production longer than on slatted floor without straw. The hazard ratio was 1.434 that means that the culling due to lameness is 1.434 times higher by the slatted floor without straw facing by solid floor with straw.
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The Number and Species of Migrating Wild Geese in Hortobágy
22-25Views:370This paper presents the total number and annual distribution of wild geese population on Puszta Hortobágy. Two migrating goose species, White-fronted Goose (Anser albifrons) and Bean Goose (Anser fabalis) contribute most to the total number of geese population. Feeding place selection of goose depend on the season. In autumn and winter, croplands largely provided food for geese. Due to selections among fields and parts of the field, sometimes relatively high grazing pressure for the whole area may be severely multiplied in some cases resulting potentially 100% shoot defoliation on the frequented sites of a wheat field.
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Using the principles of precision animal husbandry in fishbreeding
283-287Views:562Aquaculture species such as fish, crayfish, molluscs and plats are a wide range of products, with continuously growing demand worldwide. The reasons for this is that they are cheap and easy-toraise protein sources, thus having significance in food supply especially in developing countries in tropic regions, moreover, the premium category foodstuffs in developed high income countries are also belonging to this category. World annual total production of 164 million tons (2009) are made up of two sources: 1) marine and inland fisheries landings that are stagnating for several years and 2) aquaculture which is growing dynamically with annual 6% rate between 2000–2009. The latter is accounting for nearly 45% of the total supply due to the depleting marine stocks caused by overfishing. Aquaculture is growing continuously also because the production is safe and can
be planned well.
Intensive fish production systems are the representatives of precision animal production, several types exist and widespread worldwide. The modern computerized temperate water recirculation plants with several thousand m3 capacity are widespread also in Europe because they make it possible to produce even the most valuable species whole year round. A key issue in the technical/feeding outlay is to meet the demands of the cultured species the best and the operation of the system is to be safe and cost-effective. One condition for this is intensification: enable to produce more product per unit resource input or effort. The facilities need significant amount of energy, thus renewable energy sources are to be favoured for which Hungary has comparative advantages. -
Slight damage of the great green bush-cricket (Tettigonia viridissima) (Orthoptera: Tettigoniidae) in some Hungarian maize fields
65-70Views:440Characteristic cricket damage was observed in two maize fields in northern Hungary, at Máriabesnyő, a district of Gödöllő. The damage level of the two fields did not differ significantly and continual monitoring of field1 showed also a stable infestation level. T. viridissima nymphs and a female were found and observed as feeding on maize plants. The crickets must have disappeared after 18.07. because no more fresh damage was observed after this date. The chewing’s number about on one and two % of the examined plants amounted one and six a plant and their size was between one and eight cm2. This infestation was quite little and might have caused apparently no yield loss. Compared this damage of T. viridissima with former Hungarian experience, this was the usual negligible damage despite the explicit draught in July and August 2015. As regards the global warming, orthopteran damage may be more obvious in the future.
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Development of the reproductive tract of immature gilts
165-166Views:173Mechanisms of regulation of litter size in pigs are complex and depend on many factors, including genetic regulation and also physiological and anatomical development of the reproductive tract in gilts. Improvement of growth rate in present breed pigs raises the question as to whether, with the development of the reproductive tract, sexual maturity would also be attained.
The aim of the study was to assess the morphometric traits of reproductive tracts taken from gilts slaughtered at 100 kg body weight, i. e., just when they may become actively sexual mature.
This study was concluded on 80 prepubertal gilts of the Polish Landrace (PL) breed tested at the Pig Program Testing Station. The animals were kept in individual pens with control feeding and standard management. They were slaughtered after attaining 100 kg body weight. Immediately after slaughter, the reproductive tract was removed and carefully assessed. The morphometric estimation of the reproductive tract involved the
measurement of uterus weight with ligament, vagina-cervix length, uterine horns and oviducts length, ovaries weight, height and width. Uterus volume capacity was also determined, based on volumetric method of Kwaśnicki’s (1951) with own modification.
All pigs were divided into three groups in respect to age at slaughter: A – below 160 days (n=38), B – from 160 to 180 days (n=28) and C – above 180 days of age (n=14). The results were elaborated statistically computing the arithmetic means (x) for every traits and standard deviations (s). One-way analysis of variance ANOVA was performed. The significance of differences between age groups was estimated using Duncan’s test.
Calculations were performed with STATISTICA 8PL Software.
Obtained results are presented in the tables below. The most pronounced differences in the development of the reproductive tract are dependent on the age of gilts concerning only the uterus weight (P≤0.01) and uterus vagina-cervix length (P≤0.05). Gilts at age 160-180 days attained the full stage of reproductive tract development. Differences between the compared age groups of gilts dealing with the other morphometric traits
and ovary characteristics were statistically not significant. -
Ragweed components in honey
65-68Views:460The aim of this research was to prove that the syrup containing ragweed used for feeding the bees was transferred to the honey. To reach this goal we developed a method to analyse the volatile components of the samples. We applied two sample preparation methods. The first one was SPME (Solid Phase Micro Extraction) preparation from the headspace of all of the samples. In the second case only the raw leaves of the ragweed were extracted with n-hexane and dichloromethane to complete the SPME results. The measurements were performed on GC-MS equipment. Chromatograms and data evolution showed that the components of the ragweed were also present in honey so they were transferred by bees.
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Study of the Interaction Between Common Carp (Cyprinus carpio) and Silver Crucian Carp (Carassius auratus gibelio Bloch)
9-12Views:479Some of the main questions in the fish farming are the good manuring and the success of the feeding. For the best result is very important that only those fishes take place in the fishponds what we want. It seems to be easy but difficult to do. One of the main challenges of the successful fish production in fishponds, is to rid ponds of the silver crucian carp. In the course of the experiment, carp fry were stocked in 5 nursing ponds at the same stocking rate, with different (0-, 50-, 100-, 150-, 200%) stocking rates of silver crucian carp fry, respectively. During the rearing season, weekly test fishings were made to control the growth of the fishes. At the end of the experiment, the yield/hectar and the growth rates were calculated. The experiment proved that the presence of the silver crucian carp in the fishponds causes lower growth rates and productivity in common carp. In the control pond (without silver crucian carp), the average weight of the common carp was 25 g and the yield/hectar was over 900 kg, while in the pond with the most silver crucian carp, the average weight of the common carp was 9 g and the yield/hectar was only 158 kg.
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Cannibalism and its importance in Aquaculture: A review
43-54Views:1059Intracohort cannibalism may lead to significant losses during the early life stages of farmed fish. The mechanisms driving cannibalism dynamics are common across many fish species and are closely linked to the factors that influence growth variation within a population. This genetically encoded behaviour allows the individual to eliminate competitors in the competition for resources and increases the chances of survival and reproduction. Many fish species display aggression towards individuals of the same species, which can often lead to cannibalistic behavior. This foraging strategy is also present in intensive aquaculture systems, and its economical, ecological and phylogenetic implications have been debated by many researchers. Many fish species can be produced economically in recirculation aquaculture (RAS) systems, but the efficiency of larval and juvenile rearing remains a bottleneck for most species. The success of initial rearing depends on many factors. In addition to genetic factors, the level of cannibalism is mainly influenced by the applied production and feeding technology. Literature suggests that mortality during larval rearing can be as high as 50%, largely due to aggression. In the case of predatory fish species, the presence or absence of certain husbandry conditions can lead to even higher levels of cannibalism, which significantly reduces production yields by causing mortality and secondary injuries, thus further decreasing the survival rate. This review therefore aims to identify and quantify the effects of biotic and abiotic factors that influence cannibalism.