Ratoon stunting disease (RSD), caused by the bacterium Leifsonia xyli subsp xyli, is well established in most sugarcane growing regions of the world and is considered to cause more yield losses worldwide than any other sugarcane disease (Hughes, 1974). In South Africa, field trials have demonstrated that yield reductions under rainfed conditions can exceed 40% in highly susceptible varieties (Bailey and Bechet, 1986). When cane is grown under irrigation, yield losses are less noticeable but still significant in many varieties (Bailey and Bechet, 1995). It is estimated that RSD currently results in a one percent reduction in industrial production in South Africa and between 10 and 20% in other African countries where South African varieties are grown (Bailey and McFarlane, 1999; Rutherford et al., 2003). For many years, the reaction of different sugarcane varieties to RSD has been based on large, replicated yield loss trials grown over a number of years under rainfed and irrigated conditions. Although these trials provide valuable information, they are time-consuming and require large areas of uniform land. They are therefore not suitable for incorporation into a routine disease screening programme in which large numbers of genotypes are assessed for their reactions to the important diseases occurring in the industry. As a result, the susceptibility of new commercial varieties to RSD is only known several years after release to the growers. The main objective of this study was to establish a suitable method to reliably evaluate sugarcane genotypes for RSD resistance as part of the plant breeding and selection programme. Emphasis was placed on the use of the tissue blot immunoassay (TBlA) developed by Harrison and Davis (1988) and modified by Davis et al (1994), in relation to the more traditional methods of variety assessment, such as the rate of spread of RSD in the field at harvest and yield loss trials. Although the immunoassay protocol was not altered, slight modifications to the blotting procedure resulted in clearer blots that were easier to interpret. Internode position and the age of the cane were shown to have a marked effect on the extent of colonisation and ultimately the RSD resistance rating. A trial investigating the effect of the extent of colonisation on the rate of spread of RSD at harvest was conducted and showed that the relationship between spread and colonisation was highly significant. This indicated that RSD spread more rapidly through varieties such as N14 and N22 that supported high populations of L. xyli subsp xyli. The control plots in the same trial provided useful information on the extent of colonisation in the twelve varieties planted. In another trial, the effect of RSD on the yield components of six commercially grown varieties was investigated and TBIA was also conducted to compare the two methods of variety assessment. The relationship between yield loss and the extent of colonisation was significant in both the plant and first ratoon crops. TBIA produced consistent results and the ranking of the six varieties was virtually identical, despite the different growing conditions during the two crop cycles. In an attempt to screen large numbers of genotypes under controlled glasshouse conditions, .TBIA was also tested on RSD-infected sugarcane transplants (seedlings). The results of this trial were variable and could not be reliably used as a screening tool. Based on the findings of this study, TBIA has now been adopted as a quicker and cheaper alternative to immunofluorescence microscopy for diagnosing RSD in sugarcane transplants. More importantly, TBIA has been accepted as a method of screening genotypes routinely for resistance to RSD and the first screening trial was planted in November 2002. It will now be possible to inform sugarcane growers of the RSD status of the new varieties as they are released, enabling them to make more informed decisions on how to manage each variety. This information will also be valuable when selecting parents in the crossing programme, with a long term view of improving the general resistance of commercially grown varieties to RSD. This should ultimately result in a substantial reduction in RSD levels in the industry. / Thesis (M.Sc.)-University of Natal, Durban, 2003.

Physical activity (PA) and physical fitness (PF) are regarded as important elements of a healthy lifestyle (Sallis & Patrick, 1994:304; Saxena et al., 2002; Beets & Pitetti, 2004:1796). Literature revealed that adolescents are more inclined to be physically inactive and spent time on sedentary activities, such as watching television (Wang & Biddle, 2001:1; Marshall et al., 2002:413; Neumark-Sztainer et al., 2003:803; Hancox et al., 2004; Malina et al., 2004:479). Adolescents from low socio-economic communities also experience various other barriers, such as performing income-generating activities and family duties (Prista et al., 1997:455; Kriska, 2000:50), time constraints (Saxena et al., 2002), too much homework (Deflandre et al., 2004:31) and distances from sports facilities (Nahas et al., 2003), which prevent them from being physically active. Stunting, defined as height growth retardation, is also a condition that is associated with poor socio-economic status (SES) and various studies showed an occurrence of up to 19% in children (Kruger et al., 2004:566; Cameron et al., 2005:414). Although different intervention studies were conducted to improve stunting, none were based on physical activity intervention (Lunn, 2002:109; Walsh et al., 2002:6). The first aim of the study was to determine the physical fitness status and physical activity levels of 15-year-old adolescents from a previously disadvantaged community. Secondly, to determine what factors would be regarded as either barriers or motivators for 15-year-old adolescents from this previously disadvantaged community for improving their physical activity and participation in sport and for determining their perception of their own physical activity level. The next aim was to analyse the physical activity choices and aerobic endurance of these 15-year-old adolescents and the effect of a physical activity intervention programme (PAIP) on their physical activity choices and levels and aerobic endurance. The last aim of the study was to examine the effect of a PAIP on the physical fitness of stunted 15-year-old adolescents. Two high schools (an intervention school [school 1] and a control school [school 2]) in a previously disadvantaged community near Potchefstroom, South Africa, participated in this study. The learners in the control school had a slightly better socio-economic status, determined by income per capita. All Grade 8 learners in School 1 and 2 were requested to participate in the research. Two hundred and fifty-two (N=252) Grade 8 learners (116 boys and 136 girls) in School 1 and N=66 Grade 8 learners (21 boys and 45 girls) in School 2 parents/guardians granted informed consent to participate in the study. The PAIP was conducted for an hour twice a week for 19 weeks directly after school hours for learners from School 1. No physical education classes or organised sport were part of the school curriculum during the intervention. A pre-test/post-test study design was used. Standard anthropometrical procedures were used to determine body mass, stature and four skin folds. The Fitnessgram (Meredith & Welk, 1999:9) and additional fitness tests were used to determine the physical fitness levels of the participants. The Previous Day Physical Activity Recall (PDPAR) (Trost et al., 1999:342) was used to determine the physical activity levels and television watching hours during one day of the week and weekend respectively. Biological maturity status was determined by means of the 5-stage Tanner scale (Faulkner, 1996:237). The questionnaire of Rowland (1990) which deals with barriers to physical activity and participation in sport was also used. A few of the questions were adjusted and additional questions from Meredith and Welk (1999:50) were added. Demographic information on the SES (income per capita, housing, water and electricity) of the participants, as well as information on how far learners walked to school and how long it took, was also determined. The data was analysed by means of descriptive statistics, correlational analysis, frequency and rank ordering, t-testing followed by Tuckey post hoc analysis, One-and Two-way Analysis of Covariance (ANCOVA) and Tuckey-Kramer multiple comparisons. The Statistica for Windows and SAS computer programmes were used to analyse the data according to the above-mentioned aims of the study. A p-value smaller or equal to 0.05 was accepted as significant. The results of the study indicated higher mean physical fitness values in the intervention group compared to the control group. Both boys and girls in the intervention group and boys in the control group were moderately active, while only the girls in the control group showed low levels of physical activity. Longer commuting distances were found in the intervention group, while more hours of television watching were found in the control group. The aerobic fitness, flexibility and body composition of group 1 and 2 fell within the healthy fitness zone (HFZ), while their strength fell outside the healthy fitness zone, and showed negative relationships with aerobic fitness and flexibility. Television viewing time and commuting distances to school appeared to have a moderate influence on the moderate to low physical activity levels of the total group, and physical activity showed a relationship with higher fitness values. Regarding the second aim, too much homework, lack of money and family responsibilities were indicated as barriers to being physically active, while encouragement of parents and friends to participate with, were found to be motivational factors. After participation in the physical activity programme it was found that the learners' perceptions had changed and they had better knowledge of the intensity of physical activity. The results analysed for the third aim of the study indicated disappointing results regarding the effect of the intervention programme and no significant improvement was found, because of poor attendance to the programme. The learners had to be categorised in different attendance groups of the intervention programme. The group with the highest attendance (>70%) of the programme seemed to sustain their aerobic fitness the best. From the activities that were included in the physical activity programme, it was established that netball and soccer had a small effect on the physical activity choices of the group after participating in the programme. The results of the fourth aim revealed that stunted girls, who participated regularly in the programme, showed better improvement in aerobic fitness and hand grip strength after participating in the activity programme compared to non-stunted girls, while the lean body mass and flexibility on the right side of the body had improved in stunted boys. The stunted boys and girls also showed improvement in different physical fitness variables compared to non-stunted boys and girls. It can be concluded from the results of this study that participating in an after school physical activity programme is not the answer to improving the physical activity of children living in low SES environments. Such programmes are, however, needed but should be implemented during school hours. The physical activity programme, however, had a positive effect on both the physical fitness (excluding strength) and aerobic fitness as well as on their perception of physical activity and physical fitness of the adolescents, and showed some effect on the fitness of stunted adolescents. Intervention strategies should however be developed to overcome the barriers that prevented children from low SES communities from being physically active. It is also important to empower these adolescents with knowledge and skills to enable them to maintain and increase their physical activity levels. Key words: Physical fitness, physical activity, adolescence, socio-economic status, boys and girls, barriers, motivators, stunting / Thesis (Ph.D. (Human Movement Science))--North-West University, Potchefstroom Campus, 2008.

Thesis (M.Sc. (Dietetics))--North-West University, Potchefstroom Campus, 2010.

Physical activity (PA) and physical fitness (PF) are regarded as important elements of a healthy lifestyle (Sallis & Patrick, 1994:304; Saxena et al., 2002; Beets & Pitetti, 2004:1796). Literature revealed that adolescents are more inclined to be physically inactive and spent time on sedentary activities, such as watching television (Wang & Biddle, 2001:1; Marshall et al., 2002:413; Neumark-Sztainer et al., 2003:803; Hancox et al., 2004; Malina et al., 2004:479). Adolescents from low socio-economic communities also experience various other barriers, such as performing income-generating activities and family duties (Prista et al., 1997:455; Kriska, 2000:50), time constraints (Saxena et al., 2002), too much homework (Deflandre et al., 2004:31) and distances from sports facilities (Nahas et al., 2003), which prevent them from being physically active. Stunting, defined as height growth retardation, is also a condition that is associated with poor socio-economic status (SES) and various studies showed an occurrence of up to 19% in children (Kruger et al., 2004:566; Cameron et al., 2005:414). Although different intervention studies were conducted to improve stunting, none were based on physical activity intervention (Lunn, 2002:109; Walsh et al., 2002:6). The first aim of the study was to determine the physical fitness status and physical activity levels of 15-year-old adolescents from a previously disadvantaged community. Secondly, to determine what factors would be regarded as either barriers or motivators for 15-year-old adolescents from this previously disadvantaged community for improving their physical activity and participation in sport and for determining their perception of their own physical activity level. The next aim was to analyse the physical activity choices and aerobic endurance of these 15-year-old adolescents and the effect of a physical activity intervention programme (PAIP) on their physical activity choices and levels and aerobic endurance. The last aim of the study was to examine the effect of a PAIP on the physical fitness of stunted 15-year-old adolescents. Two high schools (an intervention school [school 1] and a control school [school 2]) in a previously disadvantaged community near Potchefstroom, South Africa, participated in this study. The learners in the control school had a slightly better socio-economic status, determined by income per capita. All Grade 8 learners in School 1 and 2 were requested to participate in the research. Two hundred and fifty-two (N=252) Grade 8 learners (116 boys and 136 girls) in School 1 and N=66 Grade 8 learners (21 boys and 45 girls) in School 2 parents/guardians granted informed consent to participate in the study. The PAIP was conducted for an hour twice a week for 19 weeks directly after school hours for learners from School 1. No physical education classes or organised sport were part of the school curriculum during the intervention. A pre-test/post-test study design was used. Standard anthropometrical procedures were used to determine body mass, stature and four skin folds. The Fitnessgram (Meredith & Welk, 1999:9) and additional fitness tests were used to determine the physical fitness levels of the participants. The Previous Day Physical Activity Recall (PDPAR) (Trost et al., 1999:342) was used to determine the physical activity levels and television watching hours during one day of the week and weekend respectively. Biological maturity status was determined by means of the 5-stage Tanner scale (Faulkner, 1996:237). The questionnaire of Rowland (1990) which deals with barriers to physical activity and participation in sport was also used. A few of the questions were adjusted and additional questions from Meredith and Welk (1999:50) were added. Demographic information on the SES (income per capita, housing, water and electricity) of the participants, as well as information on how far learners walked to school and how long it took, was also determined. The data was analysed by means of descriptive statistics, correlational analysis, frequency and rank ordering, t-testing followed by Tuckey post hoc analysis, One-and Two-way Analysis of Covariance (ANCOVA) and Tuckey-Kramer multiple comparisons. The Statistica for Windows and SAS computer programmes were used to analyse the data according to the above-mentioned aims of the study. A p-value smaller or equal to 0.05 was accepted as significant. The results of the study indicated higher mean physical fitness values in the intervention group compared to the control group. Both boys and girls in the intervention group and boys in the control group were moderately active, while only the girls in the control group showed low levels of physical activity. Longer commuting distances were found in the intervention group, while more hours of television watching were found in the control group. The aerobic fitness, flexibility and body composition of group 1 and 2 fell within the healthy fitness zone (HFZ), while their strength fell outside the healthy fitness zone, and showed negative relationships with aerobic fitness and flexibility. Television viewing time and commuting distances to school appeared to have a moderate influence on the moderate to low physical activity levels of the total group, and physical activity showed a relationship with higher fitness values. Regarding the second aim, too much homework, lack of money and family responsibilities were indicated as barriers to being physically active, while encouragement of parents and friends to participate with, were found to be motivational factors. After participation in the physical activity programme it was found that the learners' perceptions had changed and they had better knowledge of the intensity of physical activity. The results analysed for the third aim of the study indicated disappointing results regarding the effect of the intervention programme and no significant improvement was found, because of poor attendance to the programme. The learners had to be categorised in different attendance groups of the intervention programme. The group with the highest attendance (>70%) of the programme seemed to sustain their aerobic fitness the best. From the activities that were included in the physical activity programme, it was established that netball and soccer had a small effect on the physical activity choices of the group after participating in the programme. The results of the fourth aim revealed that stunted girls, who participated regularly in the programme, showed better improvement in aerobic fitness and hand grip strength after participating in the activity programme compared to non-stunted girls, while the lean body mass and flexibility on the right side of the body had improved in stunted boys. The stunted boys and girls also showed improvement in different physical fitness variables compared to non-stunted boys and girls. It can be concluded from the results of this study that participating in an after school physical activity programme is not the answer to improving the physical activity of children living in low SES environments. Such programmes are, however, needed but should be implemented during school hours. The physical activity programme, however, had a positive effect on both the physical fitness (excluding strength) and aerobic fitness as well as on their perception of physical activity and physical fitness of the adolescents, and showed some effect on the fitness of stunted adolescents. Intervention strategies should however be developed to overcome the barriers that prevented children from low SES communities from being physically active. It is also important to empower these adolescents with knowledge and skills to enable them to maintain and increase their physical activity levels. Key words: Physical fitness, physical activity, adolescence, socio-economic status, boys and girls, barriers, motivators, stunting / Thesis (Ph.D. (Human Movement Science))--North-West University, Potchefstroom Campus, 2008.

Thesis (M.Sc. (Dietetics))--North-West University, Potchefstroom Campus, 2010.

No description available.

A síndrome da má absorção (SMA), caracterizada pelo mau desenvolvimento e desuniformidade do lote de aves, causa importantes prejuízos econômicos à avicultura comercial. No entanto, por se tratar de uma doença multifatorial e possivelmente polimicrobiana, o envolvimento do parvovírus de galinha (ChPV) na ocorrência da SMA ainda é pouco conhecido. Com o propósito de elucidar a possível associação entre a presença do ChPV e a ocorrência da SMA, foram desenvolvidas e aplicadas ferramentas moleculares para a detecção e quantificação do ChPV em amostras de frangos comerciais no Estado do Rio Grande do Sul. Uma PCR quantitativa foi desenvolvida para detectar e quantificar cópias do genoma (CG) do ChPV em amostras de suabes de cloaca de 59 frangos saudáveis e 68 frangos com sinais clínicos sugestivos de SMA. Os resultados revelaram que todas as amostras dos dois grupos investigados, continham o genoma do ChPV. No entanto, a carga viral em frangos com SMA foi significativamente (p≤0,0001) maior (1x105 CG/100 ng DNA) do que em frangos saudáveis (1,3x103 CG/100 ng DNA). Adicionalmente às amostras de cloaca, o ChPV também foi investigado em amostras de tecidos (fígado, timo, baço, bursa de Fabricius - BF e intestino) e soros provenientes de nove frangos saudáveis e 50 frangos com sinais indicativos da SMA. O ChPV foi encontrado tanto em aves saudáveis como nas aves com SMA, no entanto, observou-se uma diferença na distribuição deste agente nos tecidos analisados. O genoma do vírus foi mais frequentemente detectado na BF, baço e intestino das aves com SMA, sendo que o intestino foi o tecido que apresentou maior carga viral. Os resultados encontrados nestes estudos demonstraram que o genoma viral estava altamente disseminado nas aves investigadas. Além disso, observou-se uma maior carga viral em frangos de corte com SMA quando comparado com aves sadias. Com base nos resultados encontrados, sugere-se que a maior carga viral de ChPV existente em aves com SMA, em relação a aves saudáveis, seja um dos fatores que favoreça a ocorrência da síndrome. / The malabsorption syndrome (MAS), characterized by the poor development and lack of uniformity of chicken flocks, causes significant economic losses to commercial poultry. However, because it is a multifactorial and possibly polymicrobial disease, the involvement of Chicken parvovirus (ChPV) in the MAS occurrence is still not clear. In order to elucidate the possible association between the presence of ChPV and the occurrence of MAS, molecular tools were developed and applied for the detection and quantification of ChPV DNA in commercial poultry samples in the state of Rio Grande do Sul. A quantitative PCR was developed to detect and quantify the ChPV genome copies (GC) in cloacal swab samples of 59 healthy broilers and 68 broilers with clinical signs suggestive of MAS. The results showed that all investigated samples of the two groups contained the genome ChPV. However, viral loads in MAS-affected animals were significantly (p≤0.0001) higher (1x105 GC/100 ng DNA) than in healthy broilers (1.3x103 GC/100 ng DNA). In addition to the cloacal samples, the presence of ChPV DNA was also investigated in tissue samples (liver, thymus, spleen, bursa of Fabricius - BF and intestine) and sera from nine healthy broilers and 50 broilers with signals indicative of MAS. The ChPV was found in healthy avian as well MAS-affected, however, there was a difference in the distribution of this agent in those tissues. The virus genome was more frequently detected in the BF, spleen and intestines of the MAS-affected broilers, and the intestines contained the highest viral loads, in comparison with other tissues. Our results demonstrated that the viral genome can be found in both healthy and MAS-affected broilers. In addition, higher viral loads were detected in broilers with signs suggestive of MAS compared to healthy birds. Based on these results, it is suggested that the greatest viral load of ChPV existing in MAS-affected broilers when compared to healthy birds, is one of the factors that favor the occurrence of the syndrome.

Doctor of Philosophy / Human Nutrition / Richard R. Rosenkranz / Child stunting refers to a condition where the child is relatively shorter in height, in comparison to their age group. Child stunting is a public health nutrition problem that hinders the development of future generations, not only physiologically but also potentially deprives their cognitive function and productivity. The demographic transition, conjoined with the epidemiological and nutrition transitions, has resulted in the coexistence of an over- and under-nutrition problem known as double burden of malnutrition, and child stunting has been a persistent part of the problem. In 2014, the World Health Organization (WHO) reported that one-fourth of the children in the developing countries have been suffering from child stunting. The objective of this research was to apply the behavioral epidemiology approach to tackle child stunting in households with double burden of malnutrition. It was hypothesized that unlike any other households with problem of child stunting, households with double burden of malnutrition possess some degree of capacity that, with proper support and direction, might enable them to help themselves reduce or prevent this nutrition-related debacle. Results from a secondary data analysis revealed that child stunting was associated with lower dietary diversity as an indication of poor food choice in the household, related to children’s nutrient requirements. Another cross-sectional study in this dissertation was conducted in an urban setting in Indonesia, and found that households with child stunting alone was associated with extreme food insecurity, while households with double burden of malnutrition ─ in the form of stunted child and overweight/obese mother (SCOWT) ─ was associated with even a mild degree of food insecurity. These results support our hypothesis that households with double burden of malnutrition lack the capacity to direct their resources properly to prevent child stunting. Most notably, we expected that the role of the mothers to manage healthy food choices through indirect measure of dietary diversity, availability and distribution within the household was lacking. In order to equip mothers with necessary components to be able to overcome these problems, we conducted a behaviorally based intervention that targeted mothers in the households experiencing the problem of double burden of malnutrition. The intervention provided the potential to achieve participant self-administered goal setting to improve diet, as well as child feeding behavior, by means of improved self-efficacy, nutrition literacy and dietary diversity. Maternal self-efficacy may be potentially enhanced by vicarious experience and active mastery experience gained during 6 sessions of behavioral intervention and verbal motivation by community health workers during 6 additional home visits. These studies, collectively comprising the present dissertation, present a message for policy makers in developing countries: nutrition literacy and behaviors for choosing healthy foods are lacking in mothers that affect both maternal and child food intake, but efforts such as improving vicarious and mastery experience on child feeding practices and healthy food choices can boost mother’s self-efficacy to engage in appropriate behaviors and improve their child’s nutrition.

Made available in DSpace on 2016-08-17T18:39:37Z (GMT). No. of bitstreams: 1 3653.pdf: 2793009 bytes, checksum: 247e499e66ebb17e3eb07a818050fc9a (MD5) Previous issue date: 2010-09-30 / The sugar cane is a semiperennial plant currently considered one of the most important crops in the world due to its ability to produce renewable energy (ethanol) and sugar. The soil quality, water availability and temperature are the main effects that made Brazil the largest producer. However some factors influence the sugarcane productivity, mainly diseases. Among them we can cite the ratoon stunting disease caused by the bacteria Leifsonia xyli subsp. xyli worldwide known to cause up-to-30% losses in the productivity. The spread of infected seedlings and the absence of external symptoms make it difficult to diagnose and require the use of laboratory techniques. Thermotherapy, cutting-material cleaning with detergent solutions and the use of resistant varieties are the key measures to contain the disease. Due to its easy spread and high rates of reduction in the productivity the objective of this study was to evaluate how the effect of four different concentrations of Lxx for four cuts, would affect the interaction varieties x cuts x bacterial concentration. Therefore it evaluates possible losses on the technological variants and the reliability of Dot blot test for the PCR from DNA extraction according to the protocol of CTAB. The analyzed data showed no significant reduction in varieties productivity in none of the four different bacterial concentrations including the control plants, as well as in technological variables on study. According to data the Dot blot technique was more sensitive than the PCR conditions utilized in this study. / A cana-de-açúcar é uma planta semi perene considerada atualmente uma das mais importantes culturas agrícolas no mundo devido a sua capacidade de produzir energia renovável (álcool) e açúcar. A qualidade do solo, a disponibilidade de água e principalmente a temperatura são os principais efeitos que tornaram o Brasil o maior produtor mundial. Entretanto alguns fatores interferem na produtividade dos canaviais principalmente as doenças. Dentre elas podemos citar o raquitismo-das-soqueiras causado pela bactéria Leifsonia xyli subsp. xyli mundialmente conhecido por causar perdas que podem chegar a 30% na produtividade. A disseminação de mudas contaminadas e a ausência de sintomas externos tornam difícil sua diagnose sendo necessário o uso de técnicas laboratoriais. Termoterapia, limpeza de material de corte com soluções detergentes e uso de variedades resistentes são as principais medidas para conter a doença. Devido a sua fácil disseminação e as altas taxas de redução na produtividade o objetivo deste trabalho foi avaliar como o efeito de quatro diferentes concentrações de Lxx, durante quatro cortes, afetaria as interações variedades x cortes x concentração bacteriana. Além de avaliar possíveis perdas nas variáveis tecnológicas e a confiabilidade do teste de Dot blot em relação ao PCR a partir da extração de DNA de acordo com o protocolo de CTAB. Os dados analisados mostraram que não houve redução significativa na produtividade das variedades em nenhuma das quatro diferentes concentrações bacterianas inclusive nas plantas testemunhas, assim como nas variáveis tecnológicas em estudo. De acordo com os dados a técnica de Dot blot mostrou-se mais sensível que a do PCR nas condições empregadas neste trabalho.

A síndrome da má absorção (SMA), caracterizada pelo mau desenvolvimento e desuniformidade do lote de aves, causa importantes prejuízos econômicos à avicultura comercial. No entanto, por se tratar de uma doença multifatorial e possivelmente polimicrobiana, o envolvimento do parvovírus de galinha (ChPV) na ocorrência da SMA ainda é pouco conhecido. Com o propósito de elucidar a possível associação entre a presença do ChPV e a ocorrência da SMA, foram desenvolvidas e aplicadas ferramentas moleculares para a detecção e quantificação do ChPV em amostras de frangos comerciais no Estado do Rio Grande do Sul. Uma PCR quantitativa foi desenvolvida para detectar e quantificar cópias do genoma (CG) do ChPV em amostras de suabes de cloaca de 59 frangos saudáveis e 68 frangos com sinais clínicos sugestivos de SMA. Os resultados revelaram que todas as amostras dos dois grupos investigados, continham o genoma do ChPV. No entanto, a carga viral em frangos com SMA foi significativamente (p≤0,0001) maior (1x105 CG/100 ng DNA) do que em frangos saudáveis (1,3x103 CG/100 ng DNA). Adicionalmente às amostras de cloaca, o ChPV também foi investigado em amostras de tecidos (fígado, timo, baço, bursa de Fabricius - BF e intestino) e soros provenientes de nove frangos saudáveis e 50 frangos com sinais indicativos da SMA. O ChPV foi encontrado tanto em aves saudáveis como nas aves com SMA, no entanto, observou-se uma diferença na distribuição deste agente nos tecidos analisados. O genoma do vírus foi mais frequentemente detectado na BF, baço e intestino das aves com SMA, sendo que o intestino foi o tecido que apresentou maior carga viral. Os resultados encontrados nestes estudos demonstraram que o genoma viral estava altamente disseminado nas aves investigadas. Além disso, observou-se uma maior carga viral em frangos de corte com SMA quando comparado com aves sadias. Com base nos resultados encontrados, sugere-se que a maior carga viral de ChPV existente em aves com SMA, em relação a aves saudáveis, seja um dos fatores que favoreça a ocorrência da síndrome. / The malabsorption syndrome (MAS), characterized by the poor development and lack of uniformity of chicken flocks, causes significant economic losses to commercial poultry. However, because it is a multifactorial and possibly polymicrobial disease, the involvement of Chicken parvovirus (ChPV) in the MAS occurrence is still not clear. In order to elucidate the possible association between the presence of ChPV and the occurrence of MAS, molecular tools were developed and applied for the detection and quantification of ChPV DNA in commercial poultry samples in the state of Rio Grande do Sul. A quantitative PCR was developed to detect and quantify the ChPV genome copies (GC) in cloacal swab samples of 59 healthy broilers and 68 broilers with clinical signs suggestive of MAS. The results showed that all investigated samples of the two groups contained the genome ChPV. However, viral loads in MAS-affected animals were significantly (p≤0.0001) higher (1x105 GC/100 ng DNA) than in healthy broilers (1.3x103 GC/100 ng DNA). In addition to the cloacal samples, the presence of ChPV DNA was also investigated in tissue samples (liver, thymus, spleen, bursa of Fabricius - BF and intestine) and sera from nine healthy broilers and 50 broilers with signals indicative of MAS. The ChPV was found in healthy avian as well MAS-affected, however, there was a difference in the distribution of this agent in those tissues. The virus genome was more frequently detected in the BF, spleen and intestines of the MAS-affected broilers, and the intestines contained the highest viral loads, in comparison with other tissues. Our results demonstrated that the viral genome can be found in both healthy and MAS-affected broilers. In addition, higher viral loads were detected in broilers with signs suggestive of MAS compared to healthy birds. Based on these results, it is suggested that the greatest viral load of ChPV existing in MAS-affected broilers when compared to healthy birds, is one of the factors that favor the occurrence of the syndrome.