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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Serial venesection : clinical, haemorheological and haematological sequelae

Challoner, Teresa January 1988 (has links)
Haematocrit in the high normal, as well as the pathological, range may be a risk factor for the development of stroke. As stroke is one of the most important causes of physical handicap attempts to reduce its incidence further are justified. Repeated small volume venesection without volume replacement is a simple method of haematocrit reduction which could be used in a controlled trial if shown to be safe and practicable. Forty three male patients (33 evaluable) with haematocrit above 0.46 without primary proliferative or secondary polycythaemia, were entered into an open study to assess the clinical, haemorheological and haematological sequelae of serial venesection. Haematocrit was reduced from a median of 0.49 to 0.385 which necessitated removal of 2.75 1 of blood (range 1.5 - 4.25 1). This resulted in a marked reduction in blood viscosity which correlated significantly with the change in haematocrit. Although haematocrit has been postulated to affect blood pressure through an effect on blood viscosity and hence peripheral resistance, no clinically significant reduction in blood pressure was observed. Despite producing a slight reactive thrombocytosis, serial venesection was not shown to increase thrombogenic activity. Bleeding time was prolonged significantly and there was a trend for a reduction in platelet adhesion. The reduction in platelet adhesion correlated significantly with the reduction in haematocrit. Maintenance of haematocrit below 0.45 necessitated further venesection on average once every 2 months during follow-up for one year. Two patients with a previous history suffered further strokes which were considered unlikely to be related to venesection. One patient had worsening of angina and 2 patients experienced intermittent palpitations when haematocrit was reduced to 0.40; these events were considered possibly due to an increase in cardiac output as a consequence of lowered haematocrit. Except in patients with cardiac disease, repeated small volume venesection without volume replacement is a safe and practicable method of reducing haematocrit.
2

Electrical and rheological properties of blood and haemorheometry

Deng, Linhong January 2000 (has links)
No description available.
3

Bioimpedance mapping of the cervix

Smith, Jye Geoffrey January 2008 (has links)
Bioimpedance spectroscopy has shown potential as a method for characterising biological tissue with the use of a tetrapolar electrode configuration. Brown et al. (2000) demonstrated that the configuration is capable of distinguishing between normal squamous epithelium and Cervical Intra-epithelial Neoplasia (CIN). However little has been done to identify the volumes of tissue that contribute to the measured impedance. Brown et al. employed a probe with a single tetrapolar electrode set thus analysing single points of tissue. The probe was required to be moved in order to "sample" other areas of tissue. This method provides no spatial information of the lesion boundaries. The overall objective of this research was to design and construct an impedance mapping system (IMS) for objective virtual biopsy of lesions by bioimpedance spectroscopy (BIS). Initially freshly excised cervical tissue was to be tested however as the study progressed this proved problematic and bovine blood was chosen as a suitable substitute. Specific aims were to; - .Investigate the spatial sensitivity distribution of the tetrapolar electrode configuration via finite element analysis (FEA). - Design a novel front end multiplexing system and multi-electrode array for mapping the impedance of the tissue of interest. - .Experimentally confirm the efficacy of the approach to identify regions of different impedances and their boundaries using bioimpedance mapping. The present study used finite element analysis (FEA) to investigate the spatial variation in sensitivity of the tetrapolar electrode configuration and identify which volumes of tissue were included in the measured impedance. An impedance mapping device was also designed and constructed utilising the tetrapolar electrode configuration in an expanded array of 25 electrodes. This array allowed the surface of an area of tissue to be mapped and lesion boundaries identified in an objective manner. FEA was also used to model lesions in healthy tissue and the sensitivity fields associated with the tetrapolar configuration. The FEA indicated that anomalous results would be obtained when a lesion was located between a drive and measurement electrode pair. In this case the lesion resulted in an increase in impedance with respect to the impedance of healthy tissue, whereas a lesion should result in a decrease in measured impedance relative to that of healthy tissue. The anomaly was found to produce false negative results for small lesions up to 0.4 mm and even a lesion with radius of approximately 0.75 mm could be undetected as the measured impedance spectrum for such a lesion is similar to that of healthy tissue. Modelling also provided insight into the sensitivity fields for an electrode array and its efficacy in accurately measuring the surface impedance of tissue and lesions of interest. The impedance mapping system (IMS) developed used an array of 25 (5x5) electrodes. The array allows 64 individual tetrapolar measurements to be obtained at 16 locations, providing an impedance map of 49 mm2 on the surface of a tissue sample. Multiple measurements at each location reduce the chance of anomalous results since these can be identified and excluded. Software was developed to display the measured impedance maps and regions of different impedance were easily identified Testing of the IMS using bovine blood showed separation of the measured impedance for a range of haematocrit between 0 - 80%. Introduced volumes of red blood cells (RBC) or clots (to mimic lesions) to the plasma (haematocrit 0%) were also clearly identified using the IMS. It was seen that measurements made at the boundary of 2 different haematocrits (ie 2 volumes of different impedance) resulted in an anomalous result as indicated by the FEA modelling. However it was demonstrated that these anomalies can be used to objectively identify the introduced RBC (lesion) boundaries. A more efficient electrode stepping sequence was also developed taking advantage of the reciprocal nature of the tetrapolar electrode configuration. This development allows for the electrode array to be doubled in size using the same components, and to sample twice the surface area in the same time taken using the initially developed system. In summary, an impedance mapping system has been modelled, designed and developed for tissue characterisation by bioimpedance measurements. The technique has been shown experimentally to be able to detect regions of differ- ent impedance and is in agreement with the finite element analysis performed. Further development of the IMS will allow progressive monitoring of suspect lesions in-vivo and better identification of their spatial distribution for biopsy.
4

Hydrostatic and thermal influences on intravascular volume determination during immersion: quantification of the f-cell ratio

Gordon, Christopher, res.cand@acu.edu.au January 2001 (has links)
Previous data have shown that the most prevalent, indirect plasma volume (PV) measurement technique, which utilises changes in haematocrit (Hct) and haemoglobin concentration ([Hb]), underestimates actual PV changes during immersion, when compared to a direct tracer-dilution method. An increase in the F-cell ratio (whole-body haematocrit (Hctw) to large-vessel haematocrit (Hctv) ratio) has been purported as a possible explanation, probably due to hydrostatic and thermally-mediated changes during water immersion. Previous investigators have not quantified the F-cell ratio during immersion. Therefore, this study sought to determine the effect of the F-cell ratio on the indirect method during both, thermoneutral and cold-water immersions. Seven healthy males were tested three times, seated upright in air (control: 21.2°C SD ±1.1), and during thermoneutral (34.5oC SD ±0.2) and cold-water immersion (18.6oC SD ±0.2), immersed to the third intercostal space for 60 min. Measurements during the immersion tests included PV (Evans blue dye column elution, Evans blue dye computer programme, and Hct [Hb]), red cell volume (RCV; sodium radiochromate), cardiac frequency (fc) and rectal temperature (Tre). Plasma volume during the control trial remained stable, and equivalent across the three tests. There was a hydrostatically-induced increase in PV during thermoneutral immersion, when determined by the Evans blue dye method (16.2%). However, the Hct/[Hb] calculation did not adequately reflect this change, and underestimated the relative PV change by 43%. In contrast, PV decreased during cold immersion when determined using the Evans blue dye method by 17.9% and the Hct/[Hb] calculation by 8.0%, respectively, representing a 52% underestimation by the latter method. There was a non-significant decline in RCV during both immersions. Furthermore, an increase (8.6%) and decrease (-14.4%) in blood volume (BV) was observed during thermoneutral and cold-water immersions, respectively. The decline in RCV during thermoneutral immersion attenuated the BV expansion. Despite the disparity between the PV methods, there was no increase in the F-cell ratio during either immersion. In contrast, there was a significant decline in the F-cell ratio during the control: air and thermoneutral immersion, which may indicate that other, undefined variables may impact on the stability of the red cell compartment. The current study is the first to show that the Hct/[Hb] method clearly underestimates PV changes during both thermoneutral and cold-water immersion. Furthermore, RCV was shown, for the first time, to decline during both immersions. However, the changes in the F-cell ratio during this study, did not account for the underestimation of PV change using the Hct/[Hb] method.
5

O monitoramento nutricional da ovelha, no período de um ano e o efeito da esquila no meio da gestação no peso ao nascer e perfil hematológico do cordeiro recém-nascido.

Dreyer, Cristina Terres January 2012 (has links)
No Brasil, a produção de ovinos é um fator de grande importância econômico-social, principalmente no estado do Rio Grande do Sul (RS). Um dos principais problemas enfrentados neste mercado são as perdas reprodutivas, representadas por baixa taxa de prenhes, baixa prolificidade e alta mortalidade perinatal de cordeiros. A deficiência de informações sobre as causas dessas perdas motivaram a realização dos experimentos aqui apresentados. No primeiro artigo dados sobre o peso (kg), condição corporal (CC) e nível sérico de beta-hidoxibutirato (BHB) foram estimados em um grupo (n=16) de ovelhas Corriedale prenhes, mantidas a campo no RS, pelo período de um ano. O grupo experimental foi tomado aleatoriamente de um rebanho de 60 ovelhas encarneiradas por monta natural no outono. Das 60 ovelhas do rebanho expostas a carneiros 53 (88,3%) foram detectadas prenhes ao exame de ultrassonografia e somente oito com partos gemelares (13,3%). O peso médio não mostrou variação estatística significativa durante o período de observação. O peso no pré-encarneiramento de 51,04kg (±1,2) mostrou um pequeno aumento até o início do encarneiramento. Esse peso sofreu um pequeno declínio entre o início e o meio da gestação. Entre o meio e o final da gestação houve um pequeno aumento de peso experimentando a partir dai um declínio, chegando ao seu menor valor de 47,93kg (±0,31), no início da lactação. A CC média das ovelhas aumentou entre o pré-encarneiramento e a início da gestação (p<0,05), sendo que a CC média de 2,9, observada no início da gestação foi a mais elevada durante o período de observação. Observou-se, por outro lado, um declínio no valor médio da CC do rebanho no meio, final da gestação e início da lactação, observando-se o valor mais baixo da CC, 2,03 (±0,11) (p<0,05), no início da lactação. Os valores séricos médios de BHB mantiveram-se estáveis durante o pré-encarneiramento e o início da gestação. A partir do meio da gestação observou-se um aumento no valor médio desse metabólito, tendo sido observado diferença significativa (p<0,05) entre o meio e o final da gestação. O valor mais elevado de 0,595 mmol/L (±0,10) foi detectado no início da lactação, sendo esse valor significativamente diferente (p<0,05) do observado no final da gestação, sugerindo um desbalanço energético. Conclui-se que o ganho de peso ou CC, observada no pré-encarneiramento foram aparentemente insuficientes para elevar a taxa de prenhez e a prolificidade do rebanho. No segundo artigo foi observado o efeito da esquila, no meio da gestação, sobre o peso ao nascer e perfil hematológico de cordeiro, peso da placenta, condição corporal das ovelhas no momento do parto, por dois anos reprodutivos consecutivos. O grupo experimental foi constituído de 41 ovelhas no primeiro ano (2010) e de 51 ovelhas no segundo ano (2011). As ovelhas, da raça Corriedale, foram mantidas em pastagem natural e cultivada durante a gestação. O encarneiramento (45 dias) foi feito por monta natura com 6-7% de carneiros reprodutivamente aptos, no outono (março/abril). Aos 50 dias da retirada dos carneiros foi realizado diagnóstico ultrassonográfico de gestação. A metade da cada grupo de ovelhas gestando, em cada ano, foi então submetida a esquila completa (grupo E). As ovelhas restantes forma mantidas com lã, constituindo o grupo NE. No ano de 2010, a esquila foi realizada aos 72 dias e em 2011 aos 74 dias de gestação, em média. Cada ovelha teve o parto acompanhado desde os primeiros sinais do trabalho até a expulsão completa do feto. Em 2010 realizou apenas a pesagem dos cordeiros, já em 2011 além da pesagem do cordeiro foi realizada a pesagem da placenta e coleta sanguínea do cordeiro recém-nascido para análise bioquímica e hematológica. O peso ao nascer dos cordeiros do grupo de ovelhas E e NE foram de 5,56kg (±1,2) e 4,84kg (±0,9) no ano de 2010 e de 5,57kg (±1,07) e 4,32kg (±1,1) para o ano de 2011 (p<0,05), nos dois anos. O peso médio da placenta do grupo de ovelhas E e NE foi de 497,5g (±98,2) e 380g (±133,5), respectivamente (p<0,05). Foi também observado, que o valor médio do hematócrito do grupo de cordeiros provenientes de ovelhas do grupo E foi menor (43%) que o valor médio dos cordeiros nascidos de ovelhas do grupo NE (46%) (p<0,05). Não foram observadas diferenças entre os níveis médios de lactado de cordeiros nascidos dois grupos. Finalmente, os dados aqui obtidos mostraram não haver diferença (p>0,05) entre o escore de CC das ovelhas, no momento do parto, com o peso ao nascer dos cordeiros nos dois grupos, durante os dois anos de experimento. / In Brazil, the sheep industry is an important social and economic sector; mainly in the state of Rio Grande do Sul (RS). One of the most pressing problem faced by the industry are the reproductive losses, caused by a low pregnancy rate, low prolificity and high perinatal mortality. The lack of information about the causes of these reproductive waists led to the conduction of two experiments here presented. In the first paper, data on body live weight (kg) (BLW), body condition score (BC) and serum level of beta-hydroxybutirate (BHB) were estimated in a group (n=16) of pregnant Corriedale ewes, grazed on natural pasture of Rio Grande do Sul (RS) state, during one year observation period. The experimental group was taking randomly from a flock of 60 ewes exposed to rams during the autumn. Of the 60 original flock ewes only 53 (88,3%) were detected pregnant at scanning and only 13% show multiple pregnancy. The BLW did not show statistics difference during the observation periods. However the BLW of 51,04kg (±1,2) showed a little increase on the pre-tupping time period. Then a small lost of BLW was observed between the beginning and middle of gestation period. From then to the final of gestation period a small increase of BLW was detected. The minor BLW of 47,93kg (±0,31) was detected at the beginning of the lactation period. The BC mean increased during the pre-tupping time and beginning of pregnancy (p<0,05), being the BC of 2.9, observed on the beginning of gestation period, the most elevated value detected. On the other hand, a decrease of the BC mean was observed starting on the middle of gestation until the beginning of lactation periods, when the lower value (2.03 ±0,11) (p<0,05) was detected. The serum values of BHB were stable on the pre-tupping and beginning of gestation periods. An increase statistically significant (p<0,05) of the metabolic was then detected between the middle and final of gestation periods. The highest value observed of 0,595 mmol/L (±0,10mmol/L) occurred at the beginning of lactation (p<0,05) when compared with the final of gestation suggesting an energetic disbalance. Finally, the information obtained in this paper suggested that the gain in BLW and BC observed in the pre-tupping time period was not enough to increase the pregnancy and prolificacy rates of the flock. In the second paper, the medium gestation shearing effect on the birth weight and haematocrit value of lambs, placental weight and body score condition (SC) of ewes at parturition, during two reproductive years was observed. The experimental group was constituted of 41 ewes on the first year (2010) and 51 ewes on the second year (2011) . The Corriedale ewes were grazed on natural and cultivated pasture during the gestation period. The ewes were exposed (45days) to 6-7% fertile rams in the autumn (March and April). The scanning was performed in all ewes fifty days after the ram’s removal. Each year one half of the pregnant ewes were sheared (S group) and the remain left unsheared (US). The sharing was performed at days 72 and 74 of gestation period on years 2010 and 2011, respectively. At the lambing time the ewes were observed during the entering labour time. In the 2010 lambing time only the lamb birth weight was taken. On the other hand, in 2011 beyond the birth weight of lambs, placental weight and lamb blood samples were collected for haematological analyses. The mean birth weight of the lambs from groups S and US observed were 5,56kg (±1,2) and 4,84kg (±0,9) in 2010 and 5,57kg (±1,07) and 4,32kg (±1,1) in 2011 (p<0,05). The placental mean weight from ewes of groups S and US were 497,5g (±98,2) and 380g (±133,5), respectively (p<0,05).The haematocrit mean value of lambs from S ewes was lower (43%) than the lambs from the US ewes (46%) (p<0,05). The lactate blood level from lambs born from S an US ewes did not show any significance difference. Finally, the data did not show any correlation (p>0,05) between the SC of ewes at lambing time and lamb birth weight in both groups on the two consecutive observation years.
6

O monitoramento nutricional da ovelha, no período de um ano e o efeito da esquila no meio da gestação no peso ao nascer e perfil hematológico do cordeiro recém-nascido.

Dreyer, Cristina Terres January 2012 (has links)
No Brasil, a produção de ovinos é um fator de grande importância econômico-social, principalmente no estado do Rio Grande do Sul (RS). Um dos principais problemas enfrentados neste mercado são as perdas reprodutivas, representadas por baixa taxa de prenhes, baixa prolificidade e alta mortalidade perinatal de cordeiros. A deficiência de informações sobre as causas dessas perdas motivaram a realização dos experimentos aqui apresentados. No primeiro artigo dados sobre o peso (kg), condição corporal (CC) e nível sérico de beta-hidoxibutirato (BHB) foram estimados em um grupo (n=16) de ovelhas Corriedale prenhes, mantidas a campo no RS, pelo período de um ano. O grupo experimental foi tomado aleatoriamente de um rebanho de 60 ovelhas encarneiradas por monta natural no outono. Das 60 ovelhas do rebanho expostas a carneiros 53 (88,3%) foram detectadas prenhes ao exame de ultrassonografia e somente oito com partos gemelares (13,3%). O peso médio não mostrou variação estatística significativa durante o período de observação. O peso no pré-encarneiramento de 51,04kg (±1,2) mostrou um pequeno aumento até o início do encarneiramento. Esse peso sofreu um pequeno declínio entre o início e o meio da gestação. Entre o meio e o final da gestação houve um pequeno aumento de peso experimentando a partir dai um declínio, chegando ao seu menor valor de 47,93kg (±0,31), no início da lactação. A CC média das ovelhas aumentou entre o pré-encarneiramento e a início da gestação (p<0,05), sendo que a CC média de 2,9, observada no início da gestação foi a mais elevada durante o período de observação. Observou-se, por outro lado, um declínio no valor médio da CC do rebanho no meio, final da gestação e início da lactação, observando-se o valor mais baixo da CC, 2,03 (±0,11) (p<0,05), no início da lactação. Os valores séricos médios de BHB mantiveram-se estáveis durante o pré-encarneiramento e o início da gestação. A partir do meio da gestação observou-se um aumento no valor médio desse metabólito, tendo sido observado diferença significativa (p<0,05) entre o meio e o final da gestação. O valor mais elevado de 0,595 mmol/L (±0,10) foi detectado no início da lactação, sendo esse valor significativamente diferente (p<0,05) do observado no final da gestação, sugerindo um desbalanço energético. Conclui-se que o ganho de peso ou CC, observada no pré-encarneiramento foram aparentemente insuficientes para elevar a taxa de prenhez e a prolificidade do rebanho. No segundo artigo foi observado o efeito da esquila, no meio da gestação, sobre o peso ao nascer e perfil hematológico de cordeiro, peso da placenta, condição corporal das ovelhas no momento do parto, por dois anos reprodutivos consecutivos. O grupo experimental foi constituído de 41 ovelhas no primeiro ano (2010) e de 51 ovelhas no segundo ano (2011). As ovelhas, da raça Corriedale, foram mantidas em pastagem natural e cultivada durante a gestação. O encarneiramento (45 dias) foi feito por monta natura com 6-7% de carneiros reprodutivamente aptos, no outono (março/abril). Aos 50 dias da retirada dos carneiros foi realizado diagnóstico ultrassonográfico de gestação. A metade da cada grupo de ovelhas gestando, em cada ano, foi então submetida a esquila completa (grupo E). As ovelhas restantes forma mantidas com lã, constituindo o grupo NE. No ano de 2010, a esquila foi realizada aos 72 dias e em 2011 aos 74 dias de gestação, em média. Cada ovelha teve o parto acompanhado desde os primeiros sinais do trabalho até a expulsão completa do feto. Em 2010 realizou apenas a pesagem dos cordeiros, já em 2011 além da pesagem do cordeiro foi realizada a pesagem da placenta e coleta sanguínea do cordeiro recém-nascido para análise bioquímica e hematológica. O peso ao nascer dos cordeiros do grupo de ovelhas E e NE foram de 5,56kg (±1,2) e 4,84kg (±0,9) no ano de 2010 e de 5,57kg (±1,07) e 4,32kg (±1,1) para o ano de 2011 (p<0,05), nos dois anos. O peso médio da placenta do grupo de ovelhas E e NE foi de 497,5g (±98,2) e 380g (±133,5), respectivamente (p<0,05). Foi também observado, que o valor médio do hematócrito do grupo de cordeiros provenientes de ovelhas do grupo E foi menor (43%) que o valor médio dos cordeiros nascidos de ovelhas do grupo NE (46%) (p<0,05). Não foram observadas diferenças entre os níveis médios de lactado de cordeiros nascidos dois grupos. Finalmente, os dados aqui obtidos mostraram não haver diferença (p>0,05) entre o escore de CC das ovelhas, no momento do parto, com o peso ao nascer dos cordeiros nos dois grupos, durante os dois anos de experimento. / In Brazil, the sheep industry is an important social and economic sector; mainly in the state of Rio Grande do Sul (RS). One of the most pressing problem faced by the industry are the reproductive losses, caused by a low pregnancy rate, low prolificity and high perinatal mortality. The lack of information about the causes of these reproductive waists led to the conduction of two experiments here presented. In the first paper, data on body live weight (kg) (BLW), body condition score (BC) and serum level of beta-hydroxybutirate (BHB) were estimated in a group (n=16) of pregnant Corriedale ewes, grazed on natural pasture of Rio Grande do Sul (RS) state, during one year observation period. The experimental group was taking randomly from a flock of 60 ewes exposed to rams during the autumn. Of the 60 original flock ewes only 53 (88,3%) were detected pregnant at scanning and only 13% show multiple pregnancy. The BLW did not show statistics difference during the observation periods. However the BLW of 51,04kg (±1,2) showed a little increase on the pre-tupping time period. Then a small lost of BLW was observed between the beginning and middle of gestation period. From then to the final of gestation period a small increase of BLW was detected. The minor BLW of 47,93kg (±0,31) was detected at the beginning of the lactation period. The BC mean increased during the pre-tupping time and beginning of pregnancy (p<0,05), being the BC of 2.9, observed on the beginning of gestation period, the most elevated value detected. On the other hand, a decrease of the BC mean was observed starting on the middle of gestation until the beginning of lactation periods, when the lower value (2.03 ±0,11) (p<0,05) was detected. The serum values of BHB were stable on the pre-tupping and beginning of gestation periods. An increase statistically significant (p<0,05) of the metabolic was then detected between the middle and final of gestation periods. The highest value observed of 0,595 mmol/L (±0,10mmol/L) occurred at the beginning of lactation (p<0,05) when compared with the final of gestation suggesting an energetic disbalance. Finally, the information obtained in this paper suggested that the gain in BLW and BC observed in the pre-tupping time period was not enough to increase the pregnancy and prolificacy rates of the flock. In the second paper, the medium gestation shearing effect on the birth weight and haematocrit value of lambs, placental weight and body score condition (SC) of ewes at parturition, during two reproductive years was observed. The experimental group was constituted of 41 ewes on the first year (2010) and 51 ewes on the second year (2011) . The Corriedale ewes were grazed on natural and cultivated pasture during the gestation period. The ewes were exposed (45days) to 6-7% fertile rams in the autumn (March and April). The scanning was performed in all ewes fifty days after the ram’s removal. Each year one half of the pregnant ewes were sheared (S group) and the remain left unsheared (US). The sharing was performed at days 72 and 74 of gestation period on years 2010 and 2011, respectively. At the lambing time the ewes were observed during the entering labour time. In the 2010 lambing time only the lamb birth weight was taken. On the other hand, in 2011 beyond the birth weight of lambs, placental weight and lamb blood samples were collected for haematological analyses. The mean birth weight of the lambs from groups S and US observed were 5,56kg (±1,2) and 4,84kg (±0,9) in 2010 and 5,57kg (±1,07) and 4,32kg (±1,1) in 2011 (p<0,05). The placental mean weight from ewes of groups S and US were 497,5g (±98,2) and 380g (±133,5), respectively (p<0,05).The haematocrit mean value of lambs from S ewes was lower (43%) than the lambs from the US ewes (46%) (p<0,05). The lactate blood level from lambs born from S an US ewes did not show any significance difference. Finally, the data did not show any correlation (p>0,05) between the SC of ewes at lambing time and lamb birth weight in both groups on the two consecutive observation years.
7

O monitoramento nutricional da ovelha, no período de um ano e o efeito da esquila no meio da gestação no peso ao nascer e perfil hematológico do cordeiro recém-nascido.

Dreyer, Cristina Terres January 2012 (has links)
No Brasil, a produção de ovinos é um fator de grande importância econômico-social, principalmente no estado do Rio Grande do Sul (RS). Um dos principais problemas enfrentados neste mercado são as perdas reprodutivas, representadas por baixa taxa de prenhes, baixa prolificidade e alta mortalidade perinatal de cordeiros. A deficiência de informações sobre as causas dessas perdas motivaram a realização dos experimentos aqui apresentados. No primeiro artigo dados sobre o peso (kg), condição corporal (CC) e nível sérico de beta-hidoxibutirato (BHB) foram estimados em um grupo (n=16) de ovelhas Corriedale prenhes, mantidas a campo no RS, pelo período de um ano. O grupo experimental foi tomado aleatoriamente de um rebanho de 60 ovelhas encarneiradas por monta natural no outono. Das 60 ovelhas do rebanho expostas a carneiros 53 (88,3%) foram detectadas prenhes ao exame de ultrassonografia e somente oito com partos gemelares (13,3%). O peso médio não mostrou variação estatística significativa durante o período de observação. O peso no pré-encarneiramento de 51,04kg (±1,2) mostrou um pequeno aumento até o início do encarneiramento. Esse peso sofreu um pequeno declínio entre o início e o meio da gestação. Entre o meio e o final da gestação houve um pequeno aumento de peso experimentando a partir dai um declínio, chegando ao seu menor valor de 47,93kg (±0,31), no início da lactação. A CC média das ovelhas aumentou entre o pré-encarneiramento e a início da gestação (p<0,05), sendo que a CC média de 2,9, observada no início da gestação foi a mais elevada durante o período de observação. Observou-se, por outro lado, um declínio no valor médio da CC do rebanho no meio, final da gestação e início da lactação, observando-se o valor mais baixo da CC, 2,03 (±0,11) (p<0,05), no início da lactação. Os valores séricos médios de BHB mantiveram-se estáveis durante o pré-encarneiramento e o início da gestação. A partir do meio da gestação observou-se um aumento no valor médio desse metabólito, tendo sido observado diferença significativa (p<0,05) entre o meio e o final da gestação. O valor mais elevado de 0,595 mmol/L (±0,10) foi detectado no início da lactação, sendo esse valor significativamente diferente (p<0,05) do observado no final da gestação, sugerindo um desbalanço energético. Conclui-se que o ganho de peso ou CC, observada no pré-encarneiramento foram aparentemente insuficientes para elevar a taxa de prenhez e a prolificidade do rebanho. No segundo artigo foi observado o efeito da esquila, no meio da gestação, sobre o peso ao nascer e perfil hematológico de cordeiro, peso da placenta, condição corporal das ovelhas no momento do parto, por dois anos reprodutivos consecutivos. O grupo experimental foi constituído de 41 ovelhas no primeiro ano (2010) e de 51 ovelhas no segundo ano (2011). As ovelhas, da raça Corriedale, foram mantidas em pastagem natural e cultivada durante a gestação. O encarneiramento (45 dias) foi feito por monta natura com 6-7% de carneiros reprodutivamente aptos, no outono (março/abril). Aos 50 dias da retirada dos carneiros foi realizado diagnóstico ultrassonográfico de gestação. A metade da cada grupo de ovelhas gestando, em cada ano, foi então submetida a esquila completa (grupo E). As ovelhas restantes forma mantidas com lã, constituindo o grupo NE. No ano de 2010, a esquila foi realizada aos 72 dias e em 2011 aos 74 dias de gestação, em média. Cada ovelha teve o parto acompanhado desde os primeiros sinais do trabalho até a expulsão completa do feto. Em 2010 realizou apenas a pesagem dos cordeiros, já em 2011 além da pesagem do cordeiro foi realizada a pesagem da placenta e coleta sanguínea do cordeiro recém-nascido para análise bioquímica e hematológica. O peso ao nascer dos cordeiros do grupo de ovelhas E e NE foram de 5,56kg (±1,2) e 4,84kg (±0,9) no ano de 2010 e de 5,57kg (±1,07) e 4,32kg (±1,1) para o ano de 2011 (p<0,05), nos dois anos. O peso médio da placenta do grupo de ovelhas E e NE foi de 497,5g (±98,2) e 380g (±133,5), respectivamente (p<0,05). Foi também observado, que o valor médio do hematócrito do grupo de cordeiros provenientes de ovelhas do grupo E foi menor (43%) que o valor médio dos cordeiros nascidos de ovelhas do grupo NE (46%) (p<0,05). Não foram observadas diferenças entre os níveis médios de lactado de cordeiros nascidos dois grupos. Finalmente, os dados aqui obtidos mostraram não haver diferença (p>0,05) entre o escore de CC das ovelhas, no momento do parto, com o peso ao nascer dos cordeiros nos dois grupos, durante os dois anos de experimento. / In Brazil, the sheep industry is an important social and economic sector; mainly in the state of Rio Grande do Sul (RS). One of the most pressing problem faced by the industry are the reproductive losses, caused by a low pregnancy rate, low prolificity and high perinatal mortality. The lack of information about the causes of these reproductive waists led to the conduction of two experiments here presented. In the first paper, data on body live weight (kg) (BLW), body condition score (BC) and serum level of beta-hydroxybutirate (BHB) were estimated in a group (n=16) of pregnant Corriedale ewes, grazed on natural pasture of Rio Grande do Sul (RS) state, during one year observation period. The experimental group was taking randomly from a flock of 60 ewes exposed to rams during the autumn. Of the 60 original flock ewes only 53 (88,3%) were detected pregnant at scanning and only 13% show multiple pregnancy. The BLW did not show statistics difference during the observation periods. However the BLW of 51,04kg (±1,2) showed a little increase on the pre-tupping time period. Then a small lost of BLW was observed between the beginning and middle of gestation period. From then to the final of gestation period a small increase of BLW was detected. The minor BLW of 47,93kg (±0,31) was detected at the beginning of the lactation period. The BC mean increased during the pre-tupping time and beginning of pregnancy (p<0,05), being the BC of 2.9, observed on the beginning of gestation period, the most elevated value detected. On the other hand, a decrease of the BC mean was observed starting on the middle of gestation until the beginning of lactation periods, when the lower value (2.03 ±0,11) (p<0,05) was detected. The serum values of BHB were stable on the pre-tupping and beginning of gestation periods. An increase statistically significant (p<0,05) of the metabolic was then detected between the middle and final of gestation periods. The highest value observed of 0,595 mmol/L (±0,10mmol/L) occurred at the beginning of lactation (p<0,05) when compared with the final of gestation suggesting an energetic disbalance. Finally, the information obtained in this paper suggested that the gain in BLW and BC observed in the pre-tupping time period was not enough to increase the pregnancy and prolificacy rates of the flock. In the second paper, the medium gestation shearing effect on the birth weight and haematocrit value of lambs, placental weight and body score condition (SC) of ewes at parturition, during two reproductive years was observed. The experimental group was constituted of 41 ewes on the first year (2010) and 51 ewes on the second year (2011) . The Corriedale ewes were grazed on natural and cultivated pasture during the gestation period. The ewes were exposed (45days) to 6-7% fertile rams in the autumn (March and April). The scanning was performed in all ewes fifty days after the ram’s removal. Each year one half of the pregnant ewes were sheared (S group) and the remain left unsheared (US). The sharing was performed at days 72 and 74 of gestation period on years 2010 and 2011, respectively. At the lambing time the ewes were observed during the entering labour time. In the 2010 lambing time only the lamb birth weight was taken. On the other hand, in 2011 beyond the birth weight of lambs, placental weight and lamb blood samples were collected for haematological analyses. The mean birth weight of the lambs from groups S and US observed were 5,56kg (±1,2) and 4,84kg (±0,9) in 2010 and 5,57kg (±1,07) and 4,32kg (±1,1) in 2011 (p<0,05). The placental mean weight from ewes of groups S and US were 497,5g (±98,2) and 380g (±133,5), respectively (p<0,05).The haematocrit mean value of lambs from S ewes was lower (43%) than the lambs from the US ewes (46%) (p<0,05). The lactate blood level from lambs born from S an US ewes did not show any significance difference. Finally, the data did not show any correlation (p>0,05) between the SC of ewes at lambing time and lamb birth weight in both groups on the two consecutive observation years.
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A comparison between the effects of black tea and rooibos on the iron status of primary school children / Petronella Breet

Breet, Petronella January 2003 (has links)
Background: Clinical studies have shown that tea consumption leads to decreased iron absorption. This finding is however, not supported by epidemiological studies, where no relationship between an increased tea consumption and a lower iron status in a population at risk of iron depletion has been found. Objectives: The main aim of this study was to compare the effects of black tea and Rooibos consumption on the iron status of primary school children in a rural setting in Potchefstroom, South Africa. Methods: One hundred and seventy five children, aged six to fifteen years, participated in this single blind, randomised, parallel intervention trial. Subjects were randomly allocated to receive two 200ml servings of either black tea or Rooibos with milk and sugar. These beverages were consumed during breaks and at the same time as the food h m the school-feeding scheme. The trial proceeded for sixteen weeks. The children received antihelminthic treatment (500mg mebendazole) at baseline. Haemoglobii haematocrit, serum iron, ferritin and transferfin were measured and total iron binding capacity and transferrin saturation were calculated. Trained fieldworkers measured dietary intakes by means of 24-hour dietary recalls and anthropometrists took anthropometric measurements. All the above mentioned data were gathered at the beginning and at the end of the intervention period. Results: Measurements indicated a study population that is malnourished in terms of anthropometrical indices and nutrient intakes. Biochemical markers of iron status also indicated that the population could be at risk of iron depletion. Changes in red blood cell count, haemoglobin, haematocrit, mean corpuscular haemoglobin (MCH), mean corpuscular volume (MCV), serum iron, transferrin, transferrin saturation, ferritin and total iron binding capacity (TIBC) did not differ significantly between the two groups. Mean red blood cell count, haematocrit, MCV, transferrin and TIBC increased significantly h m baseline to end in both groups (all p<0.0001) and MCH decreased significantly (p<.0001). Mean haemoglobin increased significantly with black tea consumption (p=0.002), although not with the consumption of Rooibos (p=0.073). Conclusion: Black tea or Rooibos consumption has similar effects on the iron status of primary school children. Iron status was not compromised by black tea in comparison with Rooibos. This questions the proposed limitation of black tea consumption as a public health strategy in order to combat iron deficiency in a population with marginal iron status. / Thesis (M.Sc. (Nutrition))--North-West University, Potchefstroom Campus, 2004.
9

A comparison between the effects of black tea and rooibos on the iron status of primary school children / Petronella Breet

Breet, Petronella January 2003 (has links)
Background: Clinical studies have shown that tea consumption leads to decreased iron absorption. This finding is however, not supported by epidemiological studies, where no relationship between an increased tea consumption and a lower iron status in a population at risk of iron depletion has been found. Objectives: The main aim of this study was to compare the effects of black tea and Rooibos consumption on the iron status of primary school children in a rural setting in Potchefstroom, South Africa. Methods: One hundred and seventy five children, aged six to fifteen years, participated in this single blind, randomised, parallel intervention trial. Subjects were randomly allocated to receive two 200ml servings of either black tea or Rooibos with milk and sugar. These beverages were consumed during breaks and at the same time as the food h m the school-feeding scheme. The trial proceeded for sixteen weeks. The children received antihelminthic treatment (500mg mebendazole) at baseline. Haemoglobii haematocrit, serum iron, ferritin and transferfin were measured and total iron binding capacity and transferrin saturation were calculated. Trained fieldworkers measured dietary intakes by means of 24-hour dietary recalls and anthropometrists took anthropometric measurements. All the above mentioned data were gathered at the beginning and at the end of the intervention period. Results: Measurements indicated a study population that is malnourished in terms of anthropometrical indices and nutrient intakes. Biochemical markers of iron status also indicated that the population could be at risk of iron depletion. Changes in red blood cell count, haemoglobin, haematocrit, mean corpuscular haemoglobin (MCH), mean corpuscular volume (MCV), serum iron, transferrin, transferrin saturation, ferritin and total iron binding capacity (TIBC) did not differ significantly between the two groups. Mean red blood cell count, haematocrit, MCV, transferrin and TIBC increased significantly h m baseline to end in both groups (all p<0.0001) and MCH decreased significantly (p<.0001). Mean haemoglobin increased significantly with black tea consumption (p=0.002), although not with the consumption of Rooibos (p=0.073). Conclusion: Black tea or Rooibos consumption has similar effects on the iron status of primary school children. Iron status was not compromised by black tea in comparison with Rooibos. This questions the proposed limitation of black tea consumption as a public health strategy in order to combat iron deficiency in a population with marginal iron status. / Thesis (M.Sc. (Nutrition))--North-West University, Potchefstroom Campus, 2004.
10

A comparison between the effects of black tea and rooibos on the iron status of primary school children / P. Breet

Breet, Petronella January 2003 (has links)
Thesis (M.Sc. (Nutrition))--North-West University, Potchefstroom Campus, 2004.

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