Introduction: Gut microbial composition has been associated with immune-mediated diseases. Breastfeeding yields a microbiota rich in bifidobacteria and promotes colonization by lactobacilli. Bifidobacteria and lactobacilli are considered health-promoting and are used as probiotics, i.e. live microbial food supplements which when ingested in adequate amounts confer a beneficial effect on the host. During weaning the developing gut immune system is exposed to an increasing variety of antigens from both foods and gut microbiota. Aims: We aimed to determine if daily feeding of 1x108 colony-forming units (CFU) of the probiotic Lactobacillus paracasei ssp. paracasei strain F19 (LF19) to healthy term infants from 4 to 13 months of age could maintain some of the beneficial effects conferred by breastfeeding on gut microbial composition, with possible effects on gut microbial function, T cell function, Th1/Th2 immune balance and eczema incidence. Study design: Infants were randomized to daily intake of cereals with (n=89) or without LF19 (n=90) from 4-13 months of age. Clinical outcome measures were monitored by diaries and a questionnaire. Stool and blood samples were obtained at 4, 6½, 9, 13 and 5½, 6½, 12 and 13 months of age, respectively. Stool samples were analyzed for lactobacilli counts by conventional culture methods and the presence of LF19 was verified by randomly amplified polymerase chain reaction (RAPD-PCR). Fecal short-chain fatty acid (SCFA) pattern, a proxy for gut microbial function, was determined by gas-liquid chromatography. After polyclonal or specific activation of T cells, the cytokine mRNA expression levels [interleukin 2 (IL2), IFN-, IL4 and IL10] were determined on isolated mRNA by quantitative real time reverse transcriptase-PCR. Serum concentrations of total and specific IgE antibodies, Haemophilus influenzae type b, diphtheria and tetanus toxoid specific IgG antibodies were analyzed by enzyme immunoassay. Results: Feeding LF19 maintained high fecal lactobacilli counts during weaning. Persistent colonization with LF19 induced differences in the fecal SCFA pattern. The cumulative incidence of eczema was lower in the probiotic group, in conjunction with a higher IFN-γ/IL4 mRNA ratio in polyclonally activated T cells. Even though there was an effect by LF19 on Th1/Th2 immune balance, there was no effect on IgE sensitization. Infants in both groups increased their capacity to express both Th1 and Th2 cytokines during the second half of infancy but the expression was still lower than that of adults. Infants in the probiotic group had lower IL2 levels after polyclonal T cell activation at 13 months of age compared with infants in the placebo group. Infants fed LF19 did not have fewer infections, but had fewer days with antibiotic prescription compared with infants fed placebo. In addition, compared to placebo, persistent colonization by LF19 enhanced specific vaccine responses to protein antigens during the course of vaccination. Conclusions: We conclude that feeding LF19 was safe, based on no observed adverse effects in our study. Infants in both groups demonstrated maturation of adaptive immune responses during weaning. Adding probiotics in complementary foods during weaning reduced the risk of eczema by 50%, with a concomitant shift towards an enhanced Th1/Th2 ratio. The reduction of eczema might be explained by probiotic effects on both T cell-mediated immune responses and reinforced gut microbial function.

This thesis is concerned with how prehistoric infants were fed in different physical and cultural environments, and in particular what impact the economic, social, and epidemiological changes associated with the development of agriculture had on infant feeding practices. In order to examine these effects, stable isotope ratio analysis has been used to assess the duration of breastfeeding and weaning in a variety of prehistoric contexts. The first study is of Pitted Ware Culture hunter-gatherers at the site of Ajvide on Gotland, Sweden. Breastfeeding usually continued for at least two years, but there was some variation in supplementary foods, which is attributed to seasonal variations in resource availability. The second study analysed a number of Neolithic and early Bronze Age sites from south-east Poland. Breastfeeding duration varied both within and between sites and ranged from six months to five years. The third study found that the infant feeding practices of two Iron Age populations on Öland, Sweden, were very varied, and infants may have been fed differently depending on their social status. The fourth study is of the childhood diet in the Únětice Culture of south-west Poland. Individual diets changed little during the lifetime, suggesting that eventual adult identity was determined early in life. A small number of infants in the study were found to have breastfed for differing lengths of time. The final paper considers the health consequences of introducing animal milks into the infant diet in a prehistoric context, and finds that their availability is unlikely to have made it possible to safely wean infants earlier. Comparison of the results from the four stable isotope studies to those of other published studies reveals that the modal age at the end of weaning was slightly lower in agricultural communities than hunter-gatherer communities, but the range of ages was similar. Weaning prior to the age of eighteen months was rare before the post-medieval period. It is argued that the gradual reduction in breastfeeding duration since the Neolithic, and the replacement of breastmilk with animal milk products, means that on the whole the development of agriculture probably served to increase infant morbidity and mortality. / <p>At the time of doctoral defense the following papers were unpublished and had a status as follows: Paper 1: Manuscript; Paper 4: Accepted; Paper 5: Forthcoming 2014</p> / Lactase Persistence and the early Cultural History of Europe (LeCHE)

Στην υπό μελέτη διατριβή διερευνήθηκε μια σειρά υποθέσεων που οδήγησαν: 1) Στη ανεύρεση μαθηματικών μοντέλων που δύνανται να υπολογίζουν το μήκος σημαντικών ανατομικών μεγεθών στη κατιούσα αορτή και κατ επέκταση να προσφέρουν βοήθεια στη επιλογή του ιδανικού μεγέθους ασκού ανά μεμονωμένο ασθενή. Δείξαμε ότι αυτά τα μοντέλα έχουν αυξημένο βαθμό προβλεπτικής αξίας. Περαιτέρω τα συγκρίναμε με τον κλασικό τρόπο επιλογής του ιδανικού μεγέθους και ευρέθησαν ανώτερα. 2)Στη δημιουργία και εξέταση των συνθηκών όπου συμβαίνει η τραυματική διαταραχή του έσω χιτώνα της κατιούσης αορτής κατά την διάρκεια της λειτουργίας του ενδοαορτικου ασκού. Η κίνηση του ασκού εντός του αορτικού αυλού είναι πολύπλοκη. Είναι σημαντική η παρατηρούμενη επαναλαμβανόμενη «επίδραση κρούσης δικην μαστιγίου» (whipping effect) του καθετήρα του ασκού στο οπίσθιο- πλάγιο αορτικό τοίχωμα. Αυτή η κίνηση φάνηκε να ενισχύεται κατά την παρατεταμένη φάση της σύμπτυξης του ασκού όταν ο ρυθμός λειτουργίας του IABP είναι 1:3. Κάτω από τέτοιες συνθήκες σημειώθηκε επιδείνωση του «score αορτικού τραύματος» που συνηγορεί υπέρ της αποφυγής του απογαλακτισμού με σταδιακή ελάττωση του ρυθμού λειτουργίας του ασκού (mode). Η επαναλαμβανόμενη κυκλική κίνηση του ενδοαορτικου ασκού επιβεβαιώθηκε κατά την διάρκεια της λειτουργίας του σε πτωματικές αθηρωματικες αορτές. Καταγραφή διαταραχών και αποκόλλησης ( fissuring) πλακών αποδόθηκε στο κύμα πίεσης που δημιουργήθηκε από την κίνηση του ασκού και λιγότερο σε άμεσο τραυματισμό. 3) Στη κλινική εξέταση των επιπλοκών καρδιοχειρουργικών ασθενών που χρειάσθηκαν θεραπεία με ενδοαορτικο ασκό, όπου βρέθηκαν συγκεκριμένα γκρουπ αυξημένου ρίσκου. Ασθενείς όπου η χρήση του ασκού χρησιμοποιηθηκε μετεγχειρητικά καθώς και ασθενείς όπου χρειάστηκαν θεραπεία με IABP μετά από αντικατάσταση βαλβίδας (ιδιαίτερα μιτροειδούς βαλβίδας) παρουσίασαν υψηλή μετεγχειρητική θνητότητα. Οι ακόλουθες μεταβλητές εμφανίσθηκαν ως παράγοντες κινδύνου αυξημένης θνησιμότητας: Θηλυκό γένος, κάπνισμα, αυξημένη προ-εγχειρητική κρεατινινη, ισχαιμικός χρόνος>80min και εισαγωγή του ασκού την μετεγχειρητική περίοδο. Με χρήση παλίνδρομης ανάλυσης, βρέθηκε ότι ιστορικό περιφερικής αγγειοπαθειας, και κλάσμα εξώθησης κάτω από 30% αποτελούν παράγοντας κινδύνου για την ανάπτυξη αγγειακών επιπλοκών. Επιπρόσθετα με την χρήση προδρομικής τυχαιοποιημένης μελέτης φάνηκε ότι απογαλακτισμός μέσω μείωσης του όγκου πλήρωσης του ασκού απετέλεσε προφυλακτικό παράγοντα για την ανάπτυξη αγγειακών επιπλοκών. Συμπερασματικά από αυτή την εργασία απορρέουν προτάσεις που πιθανώς θα επηρεάσουν την κλινική πράξη. Συγκεκριμένα προτίθεται ένας τρόπος επιλογής του ιδανικού μεγέθους ασκού που δύναται να οδηγήσει σε αποφυγή χρησιμοποίησης μεγάλων ασκών σε μικρόσωμες γυναίκες με αθηρωματικες αορτές με αποτέλεσμα περαιτέρω ελάττωση των αγγειακών επιπλοκών. Επιπρόσθετα έχοντας μελετήσει τον τρόπο κίνησης του ασκού κάτω από διαφορετικά αιμοδυναμικα σενάρια οδηγούμεθα στο συμπέρασμα ότι ο «απογαλακτισμός» πρέπει να γίνεται με ελάττωση του όγκου του ασκού (augmentation). Δείξαμε ότι αυτός ο τρόπος «απογαλακτισμού» έχει τη τάση να οδηγεί σε λιγότερες εμβολικες επιπλοκές. Τέλος έγινε ταυτοποίηση συγκεκριμένων γκρουπ ασθενών όπου αλλαγή πρακτικής όσο αναφορά την πιο πρώιμη χρησιμοποίηση του ασκού η την αλλαγή στον τρόπο απογαλακτισμού από αυτό μπορεί δυνητικά να οδηγήσει σε μείωση της θνητότητας και νοσηρότητας. / IAB size selection is based on patients height with the known risks of under or over sizing, although size selection should rely on individual hemodynamics & measurements of the length & diameter of the aorta from the left subclavian artery to the celiac axis. The first part of this project is a pilot study whereby an attempt was made, in order to predict thoracic aortic dimensions from easily obtainable external anatomical landmarks. That would potentially lead to an optimal selection of balloon sizes for an individual patient and thus reducing adverse effects of its use. The second part of the project is an experimental Angioscopic and Pathological study that set off to investigate in a mock pig circulation model, whether weaning by mode or by augmentation produces more aortic intimal trauma. The third part of this work, studied the interaction between the intraaortic balloon catheter and the human atherosclerotic aorta. With the use of an artificial circulation we obtained direct visualisation of the dynamic action of the balloon catheter within the cadaveric human aorta. Sequelae of traumatic atherosclerotic plaque rapture due to the balloon action was observed. The last study was a clinical outcome analysis with an interest in complications in a cohort of patients requiring treatment with IABP in a single Cardiothoracic Unit over a five year period. During the initial part of the project, measurements were carried out from a series of 40 cadavers during autopsy. Internal Aortic dimensions and also external somatometric distances of the thoracic cage were obtained. Using multiple regression analysis a model was devised in order to predict aortic lengths. Being able to calculate internal aortic lengths, one could be lead to a better intraaortic balloon sizing. During the second part of the study an artificial pulsatile pump was used and an intact porcine aorta was incorporated into the circuit with the inflow at the aortic valve and the outflow at the right common iliac artery. Direct angioscopic images of the interior of the aorta were obtained. Keeping steady hemodynamic conditions, an “aortic impact score” was calculated taking into account angioscopic observational variables and biopsies of the aorta at 30min, 6hours and 12 hours following counterpulsation at 1:1, 1:2 ,1:3 Versus 1:1 and 75%, 50% and 25% augmentation. The previous model was extrapolated in to the third study whereby an artificial circulation was constructed using of PVC tubing, a filter and a roller pump. A series of 5 intact cadaveric human aortas were then individually studied by placing each in series within the circuit. A balloon catheter was advanced via the left common iliac artery into the descending aorta under direct angioscopic vision. Balloon pumping was then commenced. The circuit was perfused with Normal saline at a flow rate of 3L/minute. Pump actions of 1:1 and 1:2 were simulated. A microporous filter was incorporated into the system in order to collect embolic material during balloon action. Each aorta at the end of the experiment was subjected to histological examination. During the last study data were prospectively collected within a 5 year period from a single Cardiothoracic Unit. 2697 adult patients underwent cardiac surgery, out of which 136patients (5%) required IABP. Those patients were studied in terms of balloon associated complications. We create a model of optimal balloon sizing with a high prediction value. The performance of the model was tested against the current quidelines in a cross validation way and was found to be superior. Together with height, somatometric measurements of thoracic cage could lead to more optimal IAB size selection. During the angioscopic observational studies with porcine and also cadaveric aortas the movement of the balloon catheter in relation to the aorta was observed. The balloon catheter moves relative to the wall of the aorta during inflation and deflation. Contact between the balloon and the aorta only occurs during deflation. Side branches of the aorta are not occluded by the catheter. Plaque disruption and embolus formation appear to result from pressure wave action rather than direct contact with the balloon. By calculating the aortic impact score it appears that weaning by mode produces more aortic intimal trauma. 1:3 mode produces marked intimal disruption that worsens with time. Lastly during the clinical study of patients requiring treatment with an IABP we detected significant early mortality and morbidity associated with IABP, however intermediate follow up reveals favourable outcome.

No description available.

This study investigated proteomic changes in bronchoalveolar lavage fluid (BALF) of beef calves to identify alterations related to development of naturally occurring bovine respiratory disease. BALF was collected from 162 healthy beef calves soon after weaning and transportation. Two-dimensional gel electrophoresis and mass spectrometric analysis revealed calves that later developed pneumonia had significantly lower levels of anti-inflammatory proteins including annexin A1, RAGE-binding protein, apolipoprotein-A, heat shock protein beta-1 and thioredoxin, but higher levels of antioxidant and pro-inflammatory proteins such as immunoglobulin light chain variable region, cyclophilin A, serum albumin precursor and glutathione S-transferase P. Difference in gel electrophoresis-based analysis further showed lower levels of annexin A1, annexin A2, peroxiredoxin I, calycyphosin, superoxide dismutase, macrophage capping protein and dihydrodiol dehydrogenase 3 in the calves that later developed pneumonia. Differences in annexin levels were partially confirmed by Western blot analysis. In healthy calves, immunohistochemistry revealed cytoplasmic expression of annexin A1 in surface epithelium of large airways, tracheobronchial submucosal glands, and goblet cells, and to a lesser degree in small airways but not in alveolar epithelium. Flow cytometry and immunocytochemistry labeled annexin A1 in blood and bronchoalveolar lavage neutrophils, monocytes, macrophages and lymphocytes. Annexin A2 expression was detected in surface epithelium of small airways, some mucosal lymphocytes, and endothelium, with weak expression in large airways, tracheobronchial submucosal glands and alveolar epithelium. For both proteins, the level of expression was similar in tissues collected 5 days after intrabronchial challenge with M. haemolytica compared to that from sham-inoculated calves. A sandwich ELISA for annexin A1 was developed. For use with BALF, the working range was 0.3-317 ng/ml and the sensitivity was 0.8 ng/ml. The coefficient of variation of intra-assay and the between assays was less than 20%. Together, these findings reveal annexins A1 and A2 as promising biomarkers of susceptibility to BRD in healthy at-risk calves. Further, the anti-inflammatory and pro-resolving functions of these proteins suggest roles in the pathogenesis of bacterial pneumonia of feedlot cattle. / Natural Sciences and Engineering Council (NSERC), Ontario Cattlemen’s Association, Ontario Ministry of Agriculture and Food and Ontario Veterinary College Fellowship Program

Les E. coli entérotoxinogènes (ETEC) sont souvent la cause de diarrhée post-sevrage chez le porc. Deux types d’entérotoxines sont retrouvées chez les ETEC, soit les thermolabiles, comme la toxine LT, et les thermostables, comme EAST-1, STa et STb. Cette dernière est composée de 48 acides aminés et est impliquée dans la pathologie causée par les ETEC. Pour la première fois un variant de la toxine STb fut découvert dans une étude. Nous avons alors émis l’hypothèse qu’il y a présence de variants dans la population de souches ETEC du Québec. Dans les 100 souches STb+ analysées, 23 possédaient le gène de la toxine avec une variation dans la séquence génétique : l’asparagine était présente en position 12 remplaçant ainsi l’histidine. Une corrélation entre la présence du variant et la présence de facteurs de virulence retrouvés dans ces 100 souches ETEC étudiées a été effectuée. Ce variant semble fortement associé à la toxine STa puisque toutes les souches variantes ont hybridé avec le gène codant pour cette dernière. Étant donné sa présence répandue dans la population de souches ETEC du Québec, nous avons de plus émis l’hypothèse que ce variant a des caractéristiques biologiques altérées par rapport à la toxine sauvage. L’analyse par dichroïsme circulaire a montré que le variant et la toxine sauvage ont une structure secondaire ainsi qu’une stabilité similaires. Par la suite, l’attachement au récepteur de la toxine, le sulfatide, a été étudié par résonnance plasmonique de surface (biacore). Le variant a une affinité au sulfatide légèrement réduite comparativement à la toxine sauvage. Puisque l’internalisation de la toxine fut observée dans une étude précédente et qu’elle semble liée à la toxicité, nous avons comparé l’internalisation du variant et de la toxine sauvage à l’intérieur des cellules IPEC-J2. L’internalisation du variant dans les cellules est légèrement supérieure à l’internalisation de la toxine sauvage. Ces résultats suggèrent que le variant est biochimiquement et structurellement comparable à la toxine sauvage. / Enterotoxigenic Escherichia coli (ETEC) are a major cause of post-weaning diarrhea. STb is one of two heat-stable toxins produced by ETEC and is mostly associated with pathogenic porcine isolates. For the first time, a variant of the toxin was observed in a study in 2003. Our hypothesis is that STb variants are present in ETEC strains from Quebec. To screen for alterations at the gene level, a collection of 100 STb+ ETEC strains isolated from diseased pigs was randomly selected and analyzed. A total of 23 strains had a change from His12 to Asn. An association between the presence of the variant and virulence factors present in those strains was done. These strains were also positive for STa. Since this variant seems to be widely distributed in Quebec, we hypothesize that the variant has different biological properties compared to the wild-type STb. First, the secondary structure of the variant and wild-type toxin and their thermal stability was determined by circular dichroism. Both show similar structures and thermal stability. In addition, the binding affinity with the toxin receptor, the sulfatide, was determined by surface plasmon resonance. The affinity of the wild-type for the sulfatide is slightly superior to the variant. Finally, the internalization inside IPEC-J2 cells of the variant was compared to the wild-type. The variant is able to internalize more cells than the wild-type. Altogether, these results suggest that both the variant and the wild-type toxin are biochemically and structurally similar.

An animal’s foraging ecology can vary over a range of temporal scales, mirroring seasonal and longer term changes in prey availability, as well as ontogenetic shifts in diet and distribution. Obtaining individual-based, longitudinal diet information through direct observation, however, is logistically challenging for marine mammals that pursue and consume prey underwater, and are often widely distributed. Isotopic profiling along continuously growing tissues like teeth and baleen, which archive dietary inputs at the time of growth in their stable isotope composition, allows for chronological dietary reconstructions over multi-year timespans. This thesis reports longitudinal diet studies of three Arctic whale species, killer whales (Orcinus orca), bowhead whales (Balaena mysticetus) and beluga whales (Delphinapterus leucas), derived from serial isotopic measurements along teeth and baleen. Study objectives varied by species, but general goals were to characterize seasonal, ontogenetic, and/or individual diet variation. Results revealed similar trophic-level diet, but regional spatial separation, among eastern Canadian Arctic/Northwest Atlantic killer whales. However, isotope and tooth wear differences between two individuals and the rest of the sampled whales suggested potential specialisation on sharks, while the other whales likely had diets comprising marine mammals. Cyclic isotopic variation along Eastern Canada-West Greenland bowhead whale baleen was consistent with year-round foraging, although at a reduced rate during winter. Resting zooplankton could be an important food resource outside of periods of peak productivity, and accessibility likely drives winter habitat selection. Isotopic cycling did not differ between female and male bowheads, or among age classes, indicating similar seasonal foraging patterns despite reported spatial segregation throughout their summer range. Individual beluga whales from three eastern Canadian Arctic populations varied in timing of ontogenetic diet shifts (i.e. weaning age), as well as overall trophic position, which could reflect size-specific energetic requirements and foraging capabilities. Population-specific beluga whale diet trends over a period of several decades likely reflected climate-related expansions of southern forage fish. Collectively, findings of seasonal, ontogenetic, and/or individual diet variation contribute a greater understanding of intrapopulation variation in foraging ecology of these species, and of large-scale structuring of Arctic marine ecosystems.

Intraaortic balloon counterpulsation (IABP) is the most widely used mechanical support in the assistance of a failing heart.1 Despite extensive research in this field no experimental or clinical studies have been undertaken to evaluate the most effective manner to wean IABP.2 The research reported in this thesis examines early recognition of cardiac decompensation and the management of IABP weaning. Conducted in three phases, the aim of this research programme was to determine the best manner by which to wean IABP. Phase 1 utilised a comparative descriptive design to examine IABP practice at a single cardiothoracic tertiary referral hospital. The majority of data collection was prospective, however, the required sample size saw inclusion of some retrospective data. This single centre data were than compared with an international registry to contrast IABP management and outcome. Phase 2 utilised a questionnaire survey to audit all Australasian intensive care units. Survey results were combined and statistically analysed to describe Australasian IABP management, weaning and outcome. Phase 3 utilised a quasi-experimental, one-group, posttest-only design to clinically validate a tool designed to monitor a patient's cardiac function - the 'cardiac decompensation tool'. Phase 1 saw data collected for 669 IABP insertions over an 11 year period at a single Australian hospital. This cohort was compared against the 38,606 patient dataset of The Benchmark Counterpulsation Outcomes Registry. Australian IABP practice saw later application of the device in a higher acuity patient. Australian practice demonstrated a prejudice toward intraoperative use (34.2% versus 16.6%; p=< 0.0001) and an aversion to catheter laboratory support (10.6% versus 19%; p=< 0.0001). Australian mortality while slightly higher, remained comparable (22% versus 20.8%; p=ns). Phase 2 response rate was 60%. The most common Australasian method of IABP support withdrawal was ratio reduction only (61%). Units with a documented weaning policy were less likely to require balloon reinsertion or pharmacologic escalation following IABP removal (p=0.06). Indicators most likely to demonstrate a patient's readiness for IABP weaning were blood pressure (92%), heart rate (76%) and wedge pressure (59%). Phase 3 revealed cardiac decompensation tool scores to increase immediately prior to a treatment escalation (p=0.022) and decrease immediately following this escalation in therapy (p=0.0096). There was also some indication of decreasing scores prior to treatment minimisation (p=0.005). Tool scores demonstrated a corresponding treatment fluctuation up to three hours prior to the treatment intervention. With Phase 1 and 2 revealing many aspects of IABP practice to vary, the need for some direction regarding weaning is evident. Timely recognition of cardiac decompensation during IABP weaning allows an opportunity for the earlier escalation of treatment and consequent provision of increased cardiac support. Application of the Phase 3 cardiac decompensation tool can only assist in ensuring the best manner by which to support IABP weaning.

The aim of the M.Sc. thesis was to verify possibility of weaning weatherfish larvae (Misgurnus fossilis) from the live food to the dry starter mixture using the method of co-feeding. The experiment included 3 control groups (starved control no feeding; negative control fed exclusively with dry starter mixture; positive control fed exclusively with live food) and 10 experimental groups with 5 different dates of termination of co-feeding period (at the age 13, 18, 23, 28 and 33 days post-hatching dPH) and different duration of co-feeding period (1 and 7 days). The experiment lasted from the 6 dPH, when mixed feeding was iniciated, until the age 48 dPH at the temperature of 17,8 +- 0,7 °C. The effects of termination and duration of co-feeding period upon continuous survival, morphometric and gravimetric characteristics, ratio of macrobiogenic elements and gross caloric value in somatic tissues of larvae/juveniles were evaluated. Continuous survival, morphometric and gravimetric characteristics and total content of carbon and nitrogen in somatic tissues of larvae/juveniles were increasing with extending dates of termination of co-feeding period. The rearing of weatherfish larvae was accompanied by the marked decline of survival in the period 13 20 dPH, regardless of selected diet regimes in individual groups. Within all fed groups, the worst results of continuous survival and growth were recorded in the negative control as well as groups with date of co-feeding period termination at age 13 dPH. All individuals in these groups died at age 41 dPH. At the end of the experiment, the highest values of continuous survival were achieved in the positive control as well as groups with dates of co-feeding period termination at age 23, 28 and 33 dPH, respectively. There was no significant statistical difference among these groups. Very good results in terms of morphometric and gravimetric characteristics were achieved in the groups with dates of co-feeding period termination at age 28 and 33 dPH, respectively. However, only in group with date of co-feeding period termination at age 33 dPH were achieved comparable values of morphometric characteristics with the positive control. The exception formed only values of the body height as well as dry and wet weights which were significantly higher in the positive control compared to other fed groups. The duration of the co-feeding period (either 1 or 7 days) did not affect any of the monitored characteristics. The results of the present thesis also show that the weatherfish fry best prospers on live food and, on the contrary, fry can not be reared using dry starter mixture as a sole food source. To sum up, among all tested groups that use co-feeding, only weaning of larvae with the date of co-feeding termination at age 33 dPH could be advised. In such condition the continuous survival rate as well as lenght growth reach comparable values with group exclusively fed by live food.

The goal of the thesis was to analyze reproductive performance of sows in a selected breeding facility during a three-year period. 602 litters of the breed Czech Large White pig (CLW), 7 632 litters of the Czech Large White the Czech Landrace pig (CL) and 397 litters of the Czech Landrace Czech Large White were included in my observation. The average number of born piglets 15.43 was reached in the basic set of sows, out of which there were 14.25 live-born piglets. The highest number of all born piglets was found in CL CLW (16.25 pcs), followed by CLW (16.03 pcs) and CLW CL (15.34 pcs). The highest number of live-born piglets was found in CLW (14.51 pcs), then with a slight gap followed CL CLW (14.36 pcs) and the lowest number was found in CLW CL (14.22 pcs). The average age at first conception of sows was 235.7 days. Sows, younger than 229 days at first conception gave birth to 0.39 piglets more than sows of the age 230-250 days at first conception (13.42 or 13.03 piglets). The average gestation length was 115.7 days. More piglets were born to sows with gestation length shorter than 115 days, than to sows with gestation length 115 days and more (14.55 or 14.18). The difference of 0.37 piglets was statistically confirmed as highly relevant. The average length of weaning-to-conception interval was 5 days (4.97). More piglets (by 0.44) were born to sows that were serviced within 4 days after weaning, than to sows serviced within 5 and more days (15.03 or 14.58). The difference was confirmed as statistically highly relevant. The average length of farrowing interval was found 152.9 days. Sows were categorized into three groups based on this interval, 132145 days, 146-160 days and 161200 days. Most piglets were born to sows with farrowing interval 146160 days (14.58) and least to sows with farrowing interval 161200 days (14.51).