Made available in DSpace on 2016-01-26T18:55:35Z (GMT). No. of bitstreams: 1 deyvid.pdf: 251965 bytes, checksum: 4ba035cb4ab8b1227779ef5ba9b57cb3 (MD5) Previous issue date: 2012-09-26 / The white tea in a healthy drink, but this tea can interfere in some growth factors involved in the reproduction and in the metabolism. So, the aim of this work was to verify the effect of the white tea consumption in the metabolism, number of corpora lutea and in the weight of superovulated rats. There were utilized two groups of rats: control (n=30) that received water and the group that received only white tea to drink (n=30). The experiment lasts three months and the liquid and ration consumption were verified. In the end of each month, 10 rats of each group were superovulated with 150 UI/Kg of eCG, and 150UI/Kg of hCG 48 hours later. After 48 hours of the superovulation, the rats were weighted, sacrificed and the ovaries were weighted and the corpora lutea counted, besides the blood of animals were collected for hemogram and serum biochemistry. Não houve diferença no número de corpos lúteos e peso dos ovários entre os grupos. The statistical analysis was ANOVA test followed of Tukey analysis, differences were considered when P<0.05. The group treated with white tea showed higher ingestion of ration (39.63 &#61617; 3.91 g) than control group (37.19 &#61617; 4.00 g; P<0.05). However there wasn t any difference in the animals weight. Moreover, the treated group presented lower cholesterol concentration (32.02 &#61617; 9.62 mg/dL) than control group (76.70 &#61617; 10.41 mg/dL; P<0.05). No one statistical difference was observed in the number of corpora lutea, neither in the ovaries weight between the groups. The conclusion that white tea inhibis the excessive weight gain and decreases the cholesterol concentration; furthermore the white tea does not interfere with number of corpora lutea neither in the ovaries weight of superovulated rats. / O chá branco é uma bebida saudável, porém este chá pode interferir em vários fatores de crescimento envolvidos na reprodução e no metabolismo. Portanto, este trabalho teve como objetivo verificar o efeito do consumo prolongado de chá branco no metabolismo, no número de corpos lúteos e no peso dos ovários de ratas superovuladas. Foram utilizados dois grupos de ratas: controle (n=30) que recebeu água e o grupo que recebeu apenas chá branco para beber (n=30). O experimento durou 3 meses, o consumo de líquido e de ração foi verificado. Ao final de cada mês, 10 ratas de cada grupo eram superovuladas, com 150 UI/Kg de eCG e mais 150UI/Kg de hCG depois de 48 horas. Após 48 horas da superovulação, as ratas foram pesadas, sacrificadas, os ovários foram pesados e os corpos lúteos contados. O sangue dos animais foi colhido para hemograma e bioquímica sérica. A análise estatística foi de ANOVA seguida do teste de Tukey, foram consideradas diferenças estatísticas quando P<0,05. O grupo tratado com chá branco apresentou maior ingestão de ração (39,63 &#61617; 3,91 g) em relação ao controle (37,19 &#61617; 4,00 g; P<0,05), porém não houve diferença no peso dos animais, o grupo tratado apresentou menor concentração de colesterol (32,02 &#61617; 9,62 mg/dL) que o grupo controle (76,70 &#61617; 10,41 mg/dL; P<0,05). Não houve diferença no número de corpos lúteos e peso dos ovários entre os grupos. Conclui-se que o consumo de chá branco evita o ganho excessivo de peso dos animais, diminui a concentração sérica de colesterol e não interfere no número de corpos lúteos e no peso dos ovários de ratas superovuladas.

Made available in DSpace on 2016-07-18T17:53:10Z (GMT). No. of bitstreams: 1 deyvid.pdf: 251965 bytes, checksum: 4ba035cb4ab8b1227779ef5ba9b57cb3 (MD5) Previous issue date: 2012-09-26 / The white tea in a healthy drink, but this tea can interfere in some growth factors involved in the reproduction and in the metabolism. So, the aim of this work was to verify the effect of the white tea consumption in the metabolism, number of corpora lutea and in the weight of superovulated rats. There were utilized two groups of rats: control (n=30) that received water and the group that received only white tea to drink (n=30). The experiment lasts three months and the liquid and ration consumption were verified. In the end of each month, 10 rats of each group were superovulated with 150 UI/Kg of eCG, and 150UI/Kg of hCG 48 hours later. After 48 hours of the superovulation, the rats were weighted, sacrificed and the ovaries were weighted and the corpora lutea counted, besides the blood of animals were collected for hemogram and serum biochemistry. Não houve diferença no número de corpos lúteos e peso dos ovários entre os grupos. The statistical analysis was ANOVA test followed of Tukey analysis, differences were considered when P<0.05. The group treated with white tea showed higher ingestion of ration (39.63 &#61617; 3.91 g) than control group (37.19 &#61617; 4.00 g; P<0.05). However there wasn t any difference in the animals weight. Moreover, the treated group presented lower cholesterol concentration (32.02 &#61617; 9.62 mg/dL) than control group (76.70 &#61617; 10.41 mg/dL; P<0.05). No one statistical difference was observed in the number of corpora lutea, neither in the ovaries weight between the groups. The conclusion that white tea inhibis the excessive weight gain and decreases the cholesterol concentration; furthermore the white tea does not interfere with number of corpora lutea neither in the ovaries weight of superovulated rats. / O chá branco é uma bebida saudável, porém este chá pode interferir em vários fatores de crescimento envolvidos na reprodução e no metabolismo. Portanto, este trabalho teve como objetivo verificar o efeito do consumo prolongado de chá branco no metabolismo, no número de corpos lúteos e no peso dos ovários de ratas superovuladas. Foram utilizados dois grupos de ratas: controle (n=30) que recebeu água e o grupo que recebeu apenas chá branco para beber (n=30). O experimento durou 3 meses, o consumo de líquido e de ração foi verificado. Ao final de cada mês, 10 ratas de cada grupo eram superovuladas, com 150 UI/Kg de eCG e mais 150UI/Kg de hCG depois de 48 horas. Após 48 horas da superovulação, as ratas foram pesadas, sacrificadas, os ovários foram pesados e os corpos lúteos contados. O sangue dos animais foi colhido para hemograma e bioquímica sérica. A análise estatística foi de ANOVA seguida do teste de Tukey, foram consideradas diferenças estatísticas quando P<0,05. O grupo tratado com chá branco apresentou maior ingestão de ração (39,63 &#61617; 3,91 g) em relação ao controle (37,19 &#61617; 4,00 g; P<0,05), porém não houve diferença no peso dos animais, o grupo tratado apresentou menor concentração de colesterol (32,02 &#61617; 9,62 mg/dL) que o grupo controle (76,70 &#61617; 10,41 mg/dL; P<0,05). Não houve diferença no número de corpos lúteos e peso dos ovários entre os grupos. Conclui-se que o consumo de chá branco evita o ganho excessivo de peso dos animais, diminui a concentração sérica de colesterol e não interfere no número de corpos lúteos e no peso dos ovários de ratas superovuladas.

In der vorliegenden Arbeit wurde die Bedeutung des Einflusses von Laktationsnummer, Laktationsstadium, Körperkondition und Absetzverfahren auf Merkmale der Milchleistung und Eutergesundheit einer Herde Ostfriesischer Milchschafe untersucht. Die Tiere wurden nach dem Ablammen zufällig einer Früh- bzw. Spätabsetzergruppe zugeordnet (Absetzen der Lämmer 3 bzw. 42 Tage post partum). An insgesamt 40 Terminen wurden über eine vollständige Laktation Vorgemelks-, Hälftenanfangsgemelks- und Einzeltiergemelksproben gewonnen. Das Spektrum der untersuchten Merkmale umfasste die Milchmenge, die Milchinhaltsstoffe (Fett, Eiweiß, Laktose), die klinische Untersuchung des Euters, die somatische Zellzahl, die elektrische Leitfähigkeit und bakteriologische Untersuchungen. Zusätzlich wurden das Körpergewicht und die Körperkondition der Mutterschafe erfasst. Das durchschnittliche Leistungsniveau der Herde betrug 301±101,3 kg Milch, bei mittleren Milchfett-, Milcheiweiß-, und Laktosegehalten von 5,00, 5,14 bzw. 5,00 % (150-Tageleistung). Die Laktationsnummer hatte keinen signifikanten Effekt auf die Milchleistung. Schafe der Spätabsetzer-Gruppe produzierten im Anschluss an die Säugephase eine um 300 g signifikant höhere Testtagsmilchmenge als Tiere der Frühabsetzer-Gruppe. Das Absetzverfahren hatte keinen nachweisbaren Effekt auf die Milchinhaltsstoffe. Die Herde wies eine gute Eutergesundheit auf. Der Anteil bakteriologisch positiver Schafmilchproben betrug 28,5 %. Als dominante Erreger wurden in 96,6 % der bakteriologisch positiven Schafmilchproben Koagulasenegative Staphylokokken nachgewiesen. Der Anteil bakteriologisch positiver Euterhälftenbefunde stieg signifikant mit dem Fortschreiten der Laktation und zunehmender Laktationsnummer. Eine Euterinfektion mit Koagulasenegativen Staphylokokken sowie das Verfahren des Spätabsetzens beeinflussten alle drei untersuchten Eutergesundheitsparameter (logarithmierte Zellzahl, elektrische Leitfähigkeit und Laktosegehalt) negativ (p < 0,001).

No description available.

The objectives of the study were (1) to quantify adherence rate among the study participants in the ART unit and (2) to identify factors that contribute to non-adherence. This cross sectional study was carried out at Nekemete referral clinic. Data was collected using a self-developed structured questionnaire where a total of 338 participants grouped into adherent and non-adherent based on a score derived from an adherence assessment were interviewed. Data was analysed using the Statistical Package for Social Sciences (SPSS) version 17.0. By using multivariate analysis of variables identified as correlates of adherence, non-adherence was common among those; with age between 18-30 yrs, with no education, who were not married, who had no pipe water supply, those with no electricity in the house, who perceived had no access to assistance from providers, who perceived the health care providers (HCPs) did not keep information confidentially, who had a language barrier with providers, and who were treated with a psychiatric illness. The study concludes that adherence is multi-factorial and varies significantly by individual and care setting. Psychosocial factors were found to impact adherence and should be analysed in more detail by further studies. Three psychosocial factors were independently associated with poor adherence: the study found that patients perceiving poor access; those perceiving problems in information confidentiality (and possibly experiencing stigmatisation); and having psychiatric morbidity (and possibly with less social support) are more likely to be non-adherent. Furthermore, individuals without electricity and those without piped water supply, implying low income, are at risk for non-adherence / Health Studies / M.A. (Public Health)

<p>УВОД: Diabetes mellitus (DM) је водећа глобална епидемија 21. века, сложена болест коју карактерише поремећај метаболизма и хронична хипергликемија, која доводи до развоја микроваскуларних и макроваскуларних компликација. Повишене вредности гликемије у ДМT2 доводе до поремећаја ћелија крви и њихових параметара. Истраживања су показала да хема-толошки параметри имају допринос у настанку оштећења васкуларног ендотела и учествују у развоју дегенеративних промена и путем других механизама код пацијената са дијабетесом. Циљ истраживања је да се утврде могуће промене параметара комплетне крвне слике (ККС) у зависности од гликорегулације, дужине трајања болести и њихова повезаност са микро и макро ангиопатским комликацијама код пацијената са шећерном болести тип 2 (ДМT2). МЕТОДЕ: Студија је била проспективна у трајању од једне године, од 2016. до 2017. године. Истраживањем је обухваћено укупно 137 испитаника, од којих 90 болује од ДМТ2, а 47 је здравих, оба пола, старијих од 40 година, спроведена у Дому здравља &ldquo;Др Милорад Мика Павловић&rdquo;, Инђија, Србија. Да би се утврдила могућа корелација између параметара ККС, гликорегулације у ДМT2 и дегенеративних компликација, испитаници су подељени на више начина: на групу оболелих од ДМT2 и групу здравих; групе оболелих са вредностима HbA1c&le;7% и оне са вредностима HbA1c &gt;7%, као и на групе са и без дегенеративних компликација. Коришћењем стандардних биохемијских поступака анализирани су параметри ККС, параметри гликорегулације, липидни статус, а вршена су и антропометријска мерења. Подаци од пацијената прикупљени су путем упитника и електронског картона пацијента. РЕЗУЛТАТИ: Утврђена је статистички значајна разлика између група са и без шећерне болести за WBC, еозинофилне гранулоците, хемоглобин, MCH, MCHC, SE у 2016. год, неутрофилне гранулоците, моноците, RDW, PDW, SE у 2017. год. У групи чија је дужина трајања ДМT2 већа од 6 година утврђене су повишене вредности MCHC и PDW. У односу на гликорегулацију уочене су значајне разлике у PMDW, великим тромбоцитима и RDW у групи са HbA1c&gt;7%. У односу на дегенеративне микроваскуларне компликације постоје значајне разлике у броју лимфоцита и неутрофилних гранулоцита, а за макроваскуларне компликације у вредностима PDW-а. ЗАКЉУЧАК: На основу добијених резултата нашег истраживања може се закључити да постоји повезаност између појединих хематолошких параметара и гликорегулације, обољевања од шећерне болести као и повезаност са компликацијама код пацијената са ДМТ2.</p> / <p>UVOD: Diabetes mellitus (DM) je vodeća globalna epidemija 21. veka, složena bolest koju karakteriše poremećaj metabolizma i hronična hiperglikemija, koja dovodi do razvoja mikrovaskularnih i makrovaskularnih komplikacija. Povišene vrednosti glikemije u DMT2 dovode do poremećaja ćelija krvi i njihovih parametara. Istraživanja su pokazala da hema-tološki parametri imaju doprinos u nastanku oštećenja vaskularnog endotela i učestvuju u razvoju degenerativnih promena i putem drugih mehanizama kod pacijenata sa dijabetesom. Cilj istraživanja je da se utvrde moguće promene parametara kompletne krvne slike (KKS) u zavisnosti od glikoregulacije, dužine trajanja bolesti i njihova povezanost sa mikro i makro angiopatskim komlikacijama kod pacijenata sa šećernom bolesti tip 2 (DMT2). METODE: Studija je bila prospektivna u trajanju od jedne godine, od 2016. do 2017. godine. Istraživanjem je obuhvaćeno ukupno 137 ispitanika, od kojih 90 boluje od DMT2, a 47 je zdravih, oba pola, starijih od 40 godina, sprovedena u Domu zdravlja &ldquo;Dr Milorad Mika Pavlović&rdquo;, Inđija, Srbija. Da bi se utvrdila moguća korelacija između parametara KKS, glikoregulacije u DMT2 i degenerativnih komplikacija, ispitanici su podeljeni na više načina: na grupu obolelih od DMT2 i grupu zdravih; grupe obolelih sa vrednostima HbA1c&le;7% i one sa vrednostima HbA1c &gt;7%, kao i na grupe sa i bez degenerativnih komplikacija. Korišćenjem standardnih biohemijskih postupaka analizirani su parametri KKS, parametri glikoregulacije, lipidni status, a vršena su i antropometrijska merenja. Podaci od pacijenata prikupljeni su putem upitnika i elektronskog kartona pacijenta. REZULTATI: Utvrđena je statistički značajna razlika između grupa sa i bez šećerne bolesti za WBC, eozinofilne granulocite, hemoglobin, MCH, MCHC, SE u 2016. god, neutrofilne granulocite, monocite, RDW, PDW, SE u 2017. god. U grupi čija je dužina trajanja DMT2 veća od 6 godina utvrđene su povišene vrednosti MCHC i PDW. U odnosu na glikoregulaciju uočene su značajne razlike u PMDW, velikim trombocitima i RDW u grupi sa HbA1c&gt;7%. U odnosu na degenerativne mikrovaskularne komplikacije postoje značajne razlike u broju limfocita i neutrofilnih granulocita, a za makrovaskularne komplikacije u vrednostima PDW-a. ZAKLJUČAK: Na osnovu dobijenih rezultata našeg istraživanja može se zaključiti da postoji povezanost između pojedinih hematoloških parametara i glikoregulacije, oboljevanja od šećerne bolesti kao i povezanost sa komplikacijama kod pacijenata sa DMT2.</p> / <p>BACKGROUND: Diabetes mellitus (DM) is the leading global epidemic of the 21st century,a complex disease characterized by metabolism disorders and chronic hyperglycaemia, that leads to the development of microvascular and macrovascular complications. Elevated blood glucose level in T2DM lead to disturbance of blood cells and its parameters. Previous studies have reported that haematological parameters have contributed to the development of vascular endothelial damage and are involved in the development of degenerative changes through other mechanisms in patients with diabetes. The aim of the research is to determine possible changes in the complete blood count (CBC) parameters depending on glycemic control, the duration of the disease and their association with micro and macroangiopathic complications in patients with Type 2 diabetes mellitus (T2DM). METHODS: The study was prospective from 2016. to 2017. year. The study included a total of 137 subjects, 90 with T2DM and 47 healthy, of both gender over the age of 40 years, from the Health Care Center &quot;Dr Milorad Mika Pavlović&quot; Indjija, Serbia. The subjects were divided into several ways, in order to notice the possible correlation between the CBC parameters and glucose control in T2DM, with and without T2DM, two groups with HbA1c&le;7% and with HbA1c&gt;7%, and with and without complications. We analysed CBC parameters, parameters of glycoregulation, lipid status using standard biochemical methods, performed anthropometric measurements and collected patients data by questionnaire and electronic patient card. RESULTS: There were statistical difference between group with T2DM and healthy subjects for WBC, eos, Hgb, MCH, MCHC, ESR in 2016. and neutro, mono, RDW, PDW, ESR in 2017. In the group of T2DM patients with duration of disease longer than 6 years we found elevated value of MCHC, PDW. In relationship to glycoregulation, significant differences in PMDW, large platelets and RDW were found in the group HbA1c&gt;7%. According to degenerative complications significant differences were revealed in lympho, neutro in the group with microvascular complication, and PDW in the group with macrovascular complications. CONCLUSION: Based on the resuluts of our research, it can be concluded that there is an association between particular haematological parameters and glycoregulation, diabetes mellitus, as well as relationship with degenerative complications in patients with T2DM.</p>

Bovine mastitis adversely affects the dairy industry around the world. This disease is caused by a diverse range of bacteria, broadly categorised as minor and major pathogens. In-line tools that help identify these bacterial groupings in the early stages of the disease are advantageous as timely decisions could be made before the cow develops any clinical symptoms. The first objective of this research was to identify the most informative milk parameters for the detection of minor and major bacterial pathogens. The second objective of this research was to evaluate the potential of supervised and unsupervised neural network learning paradigms for the detection of minor infected and major infected quarters in the early stages of the disease. The third objective was to evaluate the effects of different proportions of infected to non-infected cases in the training data set on the correct classification rate of the supervised neural network models as there are proportionately more non-infected cases in a herd than infected cases. A database developed at Lincoln University was used to achieve the research objectives. Starting at calving, quarter milk samples were collected weekly from 112 cows for a period of fourteen weeks, resulting in 4852 samples with complete records for somatic cell count (SCC), electrical resistance, protein percentage, fat percentage, and bacteriological status. To account for the effects of the stage of lactation on milk parameters with respect to days in milking, data was divided into three days in milk ranges. In addition, cow variation was accounted for by the sire family from which the cow originated and the lactation number of each cow. Data was pre-processed before the application of advanced analytical techniques. Somatic cell score (SCS) and electrical resistance index were derived from somatic cell count and electrical resistance, respectively. After pre-processing, the data was divided into training and validation sets for the unsupervised neural network modelling experiment and, for the supervised neural network modelling experiments, the data was divided into training, calibration and validation sets. Prior to any modelling experiments, the data was analysed using statistical and multivariate visualisation techniques. Correlations (p<0.05) were found between the infection status of a quarter and its somatic cell score (SCS, 0.86), electrical resistance index (ERI, -0.59) and protein percentage (PP, 0.33). The multivariate parallel visualisation analysis validated the correlation analysis. Due to significant multicolinearity [Correlations: SCS and ERI (-0.65: p<0.05); SCS and PP (0.32: p<0.05); ERI and PP (-0.35: p<0.05)], the original variables were decorrelated using principle component analysis. SCS and ERI were found to be the most informative variables for discriminating between non-infected, minor infected and major infected cases. Unsupervised neural network (USNN) model was trained using the training data set which was extracted from the database, containing approximately equal number of randomly selected records for each bacteriological status [not infected (NI), infected with a major pathogen (MJI) and infected with a minor pathogen (MNI)]. The USNN model was validated with the remaining data using the four principle components, days in milk (DIM), lactation number (LN), sire number, and bacteriological status (BS). The specificity of the USNN model in correctly identifying non infected cases was 97%. Sensitivities for correctly detecting minor and major infections were 89% and 80%, respectively. The supervised neural network (SNN) models were trained, calibrated and validated with several sets of training, calibration and validation data, which were randomly extracted from the database in such a way that each set has a different proportion of infected to non-infected cases ranging from 1:1 to 1:10. The overall accuracy of these models based on validation data sets gradually increased with increase in the number of non-infected cases in the data sets (80% for the 1:1, 84% for 1:2, 86% for 1:4 and 93% for 1:10). Specificities of the best models for correctly recognising non-infected cases for the four data sets were 82% for 1:1, 91% for 1:2, 94% for 1:4 and 98% for 1:10. Sensitivities for correctly recognising minor infected cases for the four data sets were 86% for 1:1, 76% for 1:2, 71% for 1:4 and 44% for 1:10. Sensitivities for correctly recognising major infected cases for the four data sets were 20% for 1:1, 20% for 1:2, 30% for 1:4 and 40% for 1:10. Overall, sensitivity for the minor infected cases decreased while that of major infected cases increased with increase in the number non-infected cases in the training data set. Due to the very low prevalence of MJI category in this particular herd, results for this category may be inconclusive. This research suggests that somatic cell score and electrical resistance index of milk were the most effective variables for detecting the infection status of a quarter followed by milk protein and fat percentage. The neural network models were able to differentiate milk containing minor and major bacterial pathogens based on milk parameters associated with mastitis. It is concluded that the neural network models can be developed and incorporated into milking machines to provide an efficient and effective method for the diagnosis of mastitis.

The objectives of the study were (1) to quantify adherence rate among the study participants in the ART unit and (2) to identify factors that contribute to non-adherence. This cross sectional study was carried out at Nekemete referral clinic. Data was collected using a self-developed structured questionnaire where a total of 338 participants grouped into adherent and non-adherent based on a score derived from an adherence assessment were interviewed. Data was analysed using the Statistical Package for Social Sciences (SPSS) version 17.0. By using multivariate analysis of variables identified as correlates of adherence, non-adherence was common among those; with age between 18-30 yrs, with no education, who were not married, who had no pipe water supply, those with no electricity in the house, who perceived had no access to assistance from providers, who perceived the health care providers (HCPs) did not keep information confidentially, who had a language barrier with providers, and who were treated with a psychiatric illness. The study concludes that adherence is multi-factorial and varies significantly by individual and care setting. Psychosocial factors were found to impact adherence and should be analysed in more detail by further studies. Three psychosocial factors were independently associated with poor adherence: the study found that patients perceiving poor access; those perceiving problems in information confidentiality (and possibly experiencing stigmatisation); and having psychiatric morbidity (and possibly with less social support) are more likely to be non-adherent. Furthermore, individuals without electricity and those without piped water supply, implying low income, are at risk for non-adherence / Health Studies / M.A. (Public Health)

Department of Public Health / MPH

La litière de fumier recyclé (LFR) est utilisée dans les fermes laitières québécoises depuis quelques années, et ce, malgré le manque de connaissances scientifiques quant aux risques reliés à l’utilisation de ce produit pour la santé des animaux. Le premier objectif de cette thèse était de décrire les méthodes de production de LFR dans un contexte québécois et les pratiques de régie associées. Le deuxième objectif du projet consistait à déterminer le potentiel de recroissance de certaines espèces bactériennes dans la LFR lorsqu’elle est contaminée. Par la suite, le niveau de propreté et la prévalence de lésions aux jarrets chez les vaches laitières exposées ou non à ce produit ont été estimés. Finalement, l’association entre l’utilisation de LFR et l’incidence de mammite sous-clinique et clinique a été évaluée. Des études observationnelles cohorte ou transversale (selon l’objectif de recherche) ont été réalisées en 2018-2019 sur 27 fermes utilisant de la LFR et 61 fermes utilisant de la litière de paille, à titre comparatif. Les visites de fermes ont permis de constater que les méthodes utilisées pour produire de la LFR n’étaient pas standardisées et qu’elles ne permettaient pas un réel compostage de la fraction solide du fumier. Les essais de recroissance ont permis de démontrer que les différentes LFR (traitée en tas, contenant fermé ou cuve rotative) ne réagissaient pas de la même façon à une inoculation par des coliformes. La LFR de cuve rotative contenait une plus faible concentration initiale de Klebsiella spp. et a montré une croissance bactérienne significative dans les premières 24 h post-inoculation. Les LFR conditionnées dans des tas ou contenants avaient quant à elles une concentration initiale importante de Klebsiella spp. et n’ont pas démontré de croissance bactérienne significative suivant leur inoculation, ce qui suggère un effet de saturation de croissance bactérienne. Au cours de l’étude transversale, 30 vaches par troupeau, en moyenne, ont été notées à l’aide d’un score de propreté sur trois zones du corps ainsi que d’un score sur l’état des jarrets, afin d’estimer leur propreté et la présence de lésions aux jarrets. Le score de propreté attribué à chaque zone du corps des vaches allait de 1 à 4, 1 étant très propre et 4 très sale. Nous avons observé que les vaches logées sur LFR avaient, en général, une meilleure propreté du pis et du bas des pattes que celles logées sur paille. La LFR avait un effet protecteur pour le risque d’avoir un score de propreté du pis ≥ 3 (rapport de cotes (RC) : 0,43) ou d’avoir un score de 4 (RC : 0,29). Les vaches logées sur LFR avaient aussi le bas des membres plus propres que celles logées sur paille avec de plus faibles cotes d’avoir un score ≥ 2 (RC : 0,45), un score ≥ 3 (RC : 0,16) ou un score de 4 (RC : 0,07). Cependant, nous n’avons pas trouvé de différence entre les deux groupes d’animaux au niveau de la propreté du flanc et du haut des pattes. Lors de leur évaluation pour la propreté, les vaches ont aussi été notées à l’aide d’un score de lésions aux jarrets allant de 0 à 3. Un score de 0 représentait un jarret parfaitement sain alors qu’un score de 3 était attribué à un jarret présentant une enflure de plus de 2,5 cm. Les deux jarrets étaient évalués et le jarret ayant reçu le score le plus élevé était inclus dans les analyses. Nous n’avons pas identifié de différence quant aux scores de jarret entre les deux groupes d’animaux. Afin d’évaluer la santé de la glande mammaire, une étude cohorte d’une durée d’un an a été mise en place à partir de la visite de la ferme. Les dynamiques de comptages de cellules somatiques ont été suivies sur 11 031 vaches durant cette période afin d’analyser l’incidence de mammite sous-clinique. Nous n’avons pas été en mesure de détecter une différence d’incidence entre les deux groupes d’animaux. Au cours de l’étude cohorte, les producteurs laitiers ont identifié et fait parvenir au laboratoire 1 144 échantillons de lait provenant de vaches atteintes de mammites cliniques. L’incidence totale de mammite clinique n’était pas plus élevée dans les fermes LFR qu’au sein des fermes paille. Cependant, lorsque nous avons analysé l’incidence de mammite clinique par agent pathogène spécifique, nous avons pu constater que les vaches logées sur LFR étaient 7,0 fois plus à risque d’expérimenter une mammite clinique causée par Klebsiella pneumoniae que celles du groupe comparatif. / Recycled manure solids (RMS) bedding has been used on Quebec dairy farms for a number of years, despite the lack of scientific knowledge about the health risks associated with the use of this product for animals. The first objective of this thesis was to describe the RMS production methods in a Quebec context and the associated management practices. The second objective of the project was to determine the potential for regrowth of certain bacterial species in the RMS when it is contaminated. Subsequently, the level of cleanliness and prevalence of hock lesions in dairy cows exposed or not to this product were estimated. Finally, the association between RMS use and the incidence of subclinical and clinical mastitis was evaluated. Observational cohort or cross-sectional studies (depending on the research objective) were conducted in 2018-2019 on 27 farms using RMS and 61 farms using straw bedding for comparison. The farm visits highlighted that the methods used to produce RMS were not standardized and did not allow for true composting of the manure solid fraction. The regrowth trials showed that different RMS (treated in heap, closed container or rotating drum) did not react in the same way to coliform inoculation. The rotating drum RMS contained a lower initial concentration of Klebsiella spp. and experienced significant bacterial growth in the first 24 hours post-inoculation. The heap or closed container RMS had a high initial concentration of Klebsiella spp. and did not show significant bacterial growth following inoculation, suggesting a saturation effect on bacterial growth. In the cross-sectional study, an average of 30 cows were measured using a cleanliness score on three body areas as well as a hock lesion score to estimate their cleanliness and the presence of hock lesions. The cleanliness score assigned to each area of the cows' body ranged from 1 to 4, with 1 being very clean and 4 being very dirty. We found that cows housed on RMS generally had better udder and lower leg cleanliness than those housed on straw. Recycled manure solids bedding had a protective effect for the risk of having an udder cleanliness score ≥ 3 (odds ratio (OR): 0,43) or having a score of 4 (OR: 0,29). Cows housed on RMS also had cleaner lower legs than those housed on straw with lower odds of having a score ≥ 2 (OR: 0,45), a score ≥ 3 (OR: 0,16) or a score of 4 (OR: 0,07). However, we found no difference between the two groups of animals in flank and upper leg cleanliness. When they were evaluated for cleanliness, cows were also measured using a hock lesion score ranging from 0 to 3. A score of 0 represented a perfectly healthy hock, while a score of 3 was assigned to a hock with swelling greater than 2.5 cm. Both hocks were scored and the hock with the higher score was included in the analyses. We did not identify any difference regarding hock lesions between the two groups of animals. To assess mammary gland health, a one-year cohort study was set up from the farm visit. Somatic cell count dynamics were followed on 11 031 cows during this period to analyze the incidence of subclinical mastitis. We were not able to detect a difference in incidence between the two groups of animals. During the cohort study, dairy farmers identified and sent to the laboratory 1 144 milk samples from cows with clinical mastitis. The total incidence of clinical mastitis was not higher on RMS farms than on straw farms. However, when we analyzed the incidence of clinical mastitis by specific pathogen, we found that cows housed on RMS were 7.0 times more likely to experience clinical mastitis caused by Klebsiella pneumoniae than those in the comparison group.