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Sheep milk is used on a global scale for the production of cheese and other derivatives, or fresh consumption. The production of milk and its derivatives, whether formal or informal, is part of a production chain, with a lower or higher level of organization depending on the regional development of the activity. The objective of this study was to describe and discuss the elements of the sheep milk production chain in Brazil using the SWOT methodology. This study was developed in 2017 based on direct research with agents linked to the sheep milk production sector of 15 properties distributed in seven states of Brazil. The agents pointed out and described the strengths and weaknesses, opportunities and threats of the segments of inputs, production, processing, and sale and distribution of products and, subsequently, these elements were organized in a SWOT matrix. In the production segment, the low adoption of adequate production techniques, data control, and knowledge of production costs are critical factors. In the processing segment, positive aspects were pointed out for the physicochemical characteristics of sheep milk, while aspects related to legislation were considered critical. The lack of culture and consumer knowledge about sheep milk products are critical points affecting the sale and distribution segment. The small scale of production, the low demand for milk and its derivatives, and the lack of specific inputs for the activity are also critical points in the production chain. However, the use of inputs from other livestock activities (mainly dairy cattle) is an important option to reduce production costs and optimize the use of resources in dairy sheep farming. Appropriate production and processing techniques for sheep milk and data and production cost control must be implemented. Despite the heterogeneity of the studied production systems, some have positive economic indicators, which demonstrate the productive and economic potential of the activity. In this scenario, intensive production aimed at products with higher added value and the growth of the consumer market are factors that stimulate the growth of dairy sheep farming and are considered opportunities, so that marketing campaigns to promote the consumption of dairy products must be carried out. The small volume of milk produced generates opportunities for the sector, due to the lack of competition and the large potential market to be explored, especially in large centers, with greater purchasing power.(AU)

O leite ovino é utilizado em escala global para a produção de queijos e outros derivados, ou para consumo in natura. A produção de leite e de seus derivados, seja formal ou informal, faz parte de uma cadeia produtiva, com menor ou maior grau de organização dependendo do desenvolvimento regional da atividade. O objetivo deste estudo foi descrever e discutir os elementos da cadeia produtiva de leite ovino no Brasil utilizando a metodologia SWOT. Este estudo foi desenvolvido em 2017 a partir de pesquisa direta com agentes ligados ao setor produtivo de leite ovino de 15 propriedades distribuídas em sete Estados do Brasil. Os agentes apontaram e descreveram os pontos fortes e fracos, as oportunidades e ameaças dos segmentos de insumos, produção, processamento, e venda e distribuição de produtos e, posteriormente, esses elementos foram organizados em uma matriz SWOT. No segmento produção, a baixa adoção de técnicas adequadas de produção, controle de dados e conhecimento dos custos de produção são fatores críticos. No segmento processamento, aspectos positivos foram apontados para as características físico-químicas do leite ovino, enquanto aspectos relacionados com a legislação foram considerados pontos críticos. A falta de cultura e conhecimento do consumidor sobre os produtos derivados do leite ovino são pontos críticos que afetam o segmento de venda e distribuição. A pequena escala de produção e a baixa demanda pelo leite e seus derivados, assim como a falta de insumos específicos para a atividade, também são pontos críticos da cadeia produtiva. Entretanto, o uso de insumos de outras atividades pecuárias (principalmente da bovinocultura leiteira) é uma opção importante para reduzir os custos de produção e otimizar o uso dos recursos na ovinocultura leiteira. Técnicas adequadas de produção e de processamento do leite ovino devem ser implementadas, assim como o controle de dados e de custos da produção. Apesar dos sistemas de produção estudados serem heterogêneos, alguns apresentam indicadores econômicos positivos, o que demonstra o potencial produtivo e econômico da atividade. Nesse cenário, a produção intensiva de produtos com maior valor agregado e o crescimento do mercado consumidor são fatores que estimulam o crescimento da ovinocultura leiteira, e são considerados oportunidades, de modo que campanhas de marketing para promover o consumo de derivados do leite devem ser realizadas. O pequeno volume de leite produzido gera oportunidades ao setor pela falta de concorrência e pelo grande mercado potencial a ser explorado, especialmente nos grandes centros, com maior poder aquisitivo.(AU)

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Gastrointestinal parasite control has been a major challenge to livestock due to the failure of anthelmintic treatments. Monepantel (MNT) was introduced in 2009 as an alternative treatment option showing a new mechanism of action against nematode parasites. To study the response of MNT in a suppressive regime, 45-Suffolk and White Dorper naturally infected sheep were divided into one of three groups, G1: control ­ with no treatment, G2: MNT at 2.5 mg kg−1 live weight (LW) PO every 30 days, and G3: MNT at 4.0 mg kgLW−1 PO every 30 days for 6 months. Every 15 days, the animals were individually weighed (body weight, BW) and checked for Famacha (FMC) and body condition score (BCS). The efficacy of MNT was evaluated weekly by fecal egg count (FEC) every month. FEC showed >97% efficacy at the start of the experiment, revealing a significant reduction for G2 (28%) and G3 (39%) in the following months. There was no treatment, BW or BCS effect between treatments; however, there was a period (P < 0.0001) and a treatment vs period interaction (P < 0.0001) for BW. The data revealed that MNT at a therapeutic and suppressive dose had a non-linear polynomial efficacy regression (R2) of 0.988 and 0.992, respectively. This original experiment demonstrates how short-interval and suppressive MNT treatments would rapidly select Haemonchus contortus, showing a fast susceptible-resistance phenotypic population replacement. Therefore, it is suggested that MNT might be carefully used in parasite control programmes alongside other management strategies (i.e. FMC, BCS) to reduce treatment frequency and the selection process for resistance.

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Temperament often depends on the animals' reaction to people, social and environmental conditions. However, little is known about the influence of changes in the pasture environment on cattle temperament. Thus, this study was designed to evaluate if an animals' temperament changes in response to being kept in a silvopastoral system. This study evaluated the effect of the tree components in a pasture environment on the temperament of any grazing cattle in integrated crop-livestock systems. A total of thirty-two Angus steers were allocated to either a livestock (L) or livestock-forest (LF) system and observed from December 2019 to February 2020. Each animal was evaluated for their reactivity score, flight speed, and number of vocalizations. The statistical model established that the animals were random effects and that the treatments and periods were fixed effects using the MIXED procedure, and the means were compared using LSMeans. The flight speed and number of vocalizations were similar in both production systems, while the reactivity score was lower for animals kept in the LF system when compared to those in the L system. This suggested that the LF system interferes positively with the animal's temperament in relation to the L production system. However, additional research is needed to understand the influence of the production system on animal temperament.

As divergências no temperamento dependem da reação dos animais às pessoas e à diferentes situações sociais e ambientais. Contudo, pouco se sabe acerca da influência de alterações no ambiente pastoril sobre o temperamento dos bovinos. Com isso, a hipótese de trabalho é de que o temperamento dos animais pode ser alterado se mantidos em sistemas pastoris arborizados. Para tanto, objetivou-se avaliar o efeito do componente arbóreo em ambiente pastoril sobre o temperamento de bovinos em pastejo em sistemas integrados de produção agropecuária. Foram avaliados 32 novilhos da raça Angus alocados em dois sistemas pecuária (PEC) e pecuária-floresta (PF) durante o período de dezembro de 2019 a fevereiro de 2020, no qual foi mensurado: o escore de reatividade dos animais; a velocidade de fuga e o número de vocalizações. O modelo estatístico utilizado considerou como efeito fixo de tratamentos e períodos e efeitos aleatórios dos animais, utilizando o procedimento MIXED, as médias foram comparadas pelo recurso lsmeans. A velocidade de saída e número de vocalizações foram similares entre os sistemas de produção. O escore de reatividade foi menor para os animais mantidos no sistema PF quando comparados aos do tratamento PEC. O sistema PF interfere positivamente no temperamento animal em relação ao sistema de produção PEC, observado pelo menor escore de reatividade nos animais mantidos neste sistema. Contudo, o estudo sobre a influência da integração de sistemas sobre o temperamento animal exige mais pesquisas para revelar o potencial deste modelo de produção sobre o comportamento animal.

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The aim of this study was to evaluate the influence of weaning and concentrate supplementation on the characteristics of carcass cuts and longissimus muscle of Suffolk lambs finished on a Tifton 85 (Cynodon spp.) pasture. Weaning and concentrate supplementation strategies were evaluated in four finishing systems: i) non-weaned and non-supplemented lambs; ii) non-weaned lambs supplemented with concentrate in creep feeding; iii) weaned and non-supplemented lambs; and iv) weaned lambs supplemented with concentrate. In the systems with weaning, lambs were weaned at 46 ± 6 days of age. In the systems with supplementation, the concentrate was offered daily at 2% of lambs' body weight. Weaning led to a decrease, whereas supplementation led to an increase in carcass cut weights. Supplemented lambs had lower yields of neck and uncovered ribs, and higher yields of breast + flank and loin. The characteristics of loin eye and fat thickness over the longissimus muscle presented lower values in weaned lambs and higher values in supplemented lambs. Keeping lambs with their dams and offering concentrate supplementation until slaughter are strategies recommended to obtain heavier cuts with increased muscularity and fat content.(AU)

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The aim of this study was to evaluate the influence of weaning and concentrate supplementation on the characteristics of carcass cuts and longissimusmuscle of Suffolk lambs finished ona Tifton 85 (Cynodonspp.) pasture. Weaning and concentrate supplementation strategies were evaluated in four finishing systems: i) non-weaned and non-supplemented lambs; ii) non-weaned lambs supplemented with concentrate in creep feeding;iii) weaned and non-supplemented lambs; and iv) weaned lambs supplemented with concentrate. In the systems with weaning, lambs were weaned at 46 ± 6 days of age. In the systems with supplementation, the concentrate was offered daily at 2% of lambs body weight. Weaning led to a decrease, whereas supplementation led to an increase in carcass cut weights. Supplemented lambs had lower yields of neck and uncovered ribs, and higher yields of breast + flank and loin. The characteristics of loin eye and fat thicknessover the longissimusmuscle presented lower values in weaned lambs and higher values in supplemented lambs. Keeping lambs with their dams and offering concentrate supplementation until slaughter are strategies recommended to obtain heavier cuts with increased muscularity and fat content.(AU)

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This study aims to report the detection of N. caninum DNA in a newborn lamb (1) with neurological signs and congenital neosporosis and in a stillborn lamb (2), both born from the same ewe in a herd of Southern Brazil. The lambs were born during different pregnancies of a Suffolk ewe seropositive to N. caninum and seronegative to T. gondii. Histopathological lesions were observed only in the central nervous system of the lambs. The newborn lamb (1) showed mild and focal gliosis in the frontal lobe. In the hippocampal region of the stillborn lamb (2), lymphoplasmacytic perivascular cuffs and N. caninum cysts were observed in the cytoplasm of neurons and confirmed by IHC. PCR was performed using brain samples to detect the protozoa N. caninum and Toxoplasma gondii. The infection with N. caninum was confirmed in the newborn lamb (1) by PCR and in the stillborn lamb (2) by histopathology, immunohistochemistry, and PCR tests.

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We assessed the effects of high-intensity and low-frequency (HILF) vs. low-intensity and high-frequency (LIHF) grazing on herbage production and performance of beef cattle grazing sorghum pastures. The experimental design was a complete randomized block with two treatments and four replicates (paddocks), carried out in 2014/15. The management target of 50 and 30 cm for pre- and post-grazing, respectively, a LIHF grazing management strategy oriented to maximize beef cattle herbage intake per unit time, was compared with a HILF grazing management strategy of 80 and 20 cm for pre- and post-grazing, respectively, aiming to maximize herbage accumulation and harvest efficiency. Sixteen Brangus steers of 15-month-old and 265 ± 21 kg of live weight (LW) were randomly distributed to paddocks (experimental units). The LIHF resulted in shorter rest periods when compared with the HILF. The greater leaf lamina mass in LIHF allowed greater sward light interception at post-grazing, resulting in greater total herbage production than HILF (7581 and 4154 kg DM/ha, respectively). The average daily gain (ADG) of steers was greater for the LIHF than for the HILF treatment (0.950 and 0.702 kg/animal, respectively); however, even with a greater stocking rate in the HILF, there was no difference for LW gain per ha, with an average of 4 kg LW/ha/day. Our findings demonstrated that the LIHF strategy that is based on offering to the animals an optimal sward structure to favor the maximum herbage intake rate fosters greater herbage production, harvesting efficiency, and ADG without compromising LW gain per area of beef steers, despite the lower herbage harvested per stocking cycle.

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This study aimed to characterize 24 representative sheep production farms from five mesoregions in the state of Paraná, Southern Brazil, so that economic and productive improvement strategies could be proposed. The representative farms for each region were defined at meetings with sheep farmers and technicians via the rapid appraisal methodology and represent 65% of the state's flock. The information of each representative farm was collected between March 2015 and February 2016. Principal component analysis was used to verify the relationships among the different variables that characterized the farms. These characteristics were: number of ewes (V1), total cost per kilogram of revenue-generating product (V2), feeding costs (V3), labor costs (V4), facility and equipment depreciation costs (V5), and gross margin in the production cycle (V6). Cluster analysis was performed, resulting in three distinct groups: one including eight, another seven, and the third, nine farms. The results aided in classifying the farms into groups with similar characteristics, such as production scale, reproductive efficiency, technical and managerial control, appreciation of cooperatives, and availability of continuous technical assistance. The production scale, reproductive and productive efficiency, adoption of technologies, and cooperative organizational structure can be emphasized as positive performance benchmarks and were the most important aspects to achieve positive economic results.

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Sheep production on pasture plays an important role in subtropical climates around the world, with great economic and environmental relevance to those regions. However, this production is much lower than its true potential in subtropical regions, largely due to lack of knowledge of how to feed grazing lambs, and mitigate gastrointestinal parasite infections. Due to weather instability and the high growth rate of tropical grasses, it is difficult to adjust the quality and quantity of feed consumed by lambs. In addition, due to warm, wet weather during spring, summer, and autumn, gastrointestinal parasite infection can be intense on subtropical pastures. Thus, the objective of this paper is to summarize 17 years of research in southern regions of Brazil testing alternative management for sheep farmers under these challenging conditions. Our review indicates that ewes play important roles raising their lambs. Besides protecting and providing milk, they leave a better pasture structure for lamb nutrition. The use of creep feeding and creep grazing are additional alternatives to improve lamb growth. However, feeding supplementation with concentrate can deteriorate pasture quality at the end of the summer-autumn season. Gastrointestinal parasitic infections can be reduced with improved lamb nutrition, although L3 larvae of Haemonchus contortus can be present at various pasture heights. This indicates that it is difficult to control L3 ingestion solely by manipulating grazing heights. We summarize important technologies for raising lambs on pasture-based systems to make the best of high herbage growth and minimize intense parasitic infections common in subtropical regions. We discuss research results in light of the latest studies from other ecoregions and climates, although there is a lack of similar research in subtropical regions of the world.

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The study of factors influencing animal intake can provide a better understanding of the dynamics of the pasture ecosystem and serve as a basis for managing livestock in a more efficient way. We measured different sward surface heights of tall fescue in the process of short-term intake rate of sheep. There was a significant effect of sward surface height on herbage mass (P < 0.001), leaf lamina mass (P < 0.001), other species mass (P = 0.02), bite mass (P = 0.01) and short-term intake rate (P = 0.03) of sheep. There was a quadratic fit between time per bite and bite mass (P = 0.006). Multivariate analysis showed that the short-term intake rate and bite mass were positively correlated (r = 0.97), bite rate and total jaw movement rate were positively correlated but both were negatively correlated with time per bite. The sward surface height of tall fescue corresponding to the maximum short-term herbage intake rate was 22.3 cm. The underlying processes were driven by the bite mass, which was influenced by the leaf lamina bulk density and its consequences upon time per bite. This sward surface height can be adopted as a pre-grazing target for rotational stocking systems to optimize sheep nutrition on pastures.

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Titanium dioxide (TiO2) is an external marker used to estimate fecal output based on forage intake of grazing ruminants; however, its use as marker for grazing sheep still needs attention. In the present study the TiO2 role to estimate fecal output of sheep grazing annual ryegrass was tested. Two essays were conducted in sequence using the same forage and animals. Six lacaune lambs were housed in metabolic cages. Lambs were administered 1 g TiO2 in a single (at 8:30 am, essay 1), or in two daily doses (at 8:30 am and 4:30 pm, essay 2). In both essays the TiO2 administration was followed by a 7-day period to stabilize the fecal excretion of the marker and then by a 5-day period for total collection of feces. Observed and TiO2-based estimated fecal outputs were compared, with or without correction for TiO2 fecal recovery rate (kTiO2). The kTiO2 was around 1.0 and the estimated fecal outputs were similar to the observed ones (p>0.05), regardless the number of daily doses. These results suggested that TiO2, administered in single or two daily doses, can be used as an external marker in grazing sheep.(AU)

O dióxido de titânio (TiO2) é um marcador externo utilizado para estimativas da excreção fecal, visando medidas de consumo de forragem em ruminantes a pasto. No entanto, o uso deste marcador para ovinos em pastejo ainda pode ser melhor explorado. Neste trabalho, o TiO2 foi testado para estimar a produção fecal de ovinos ingerindo azevém anual. Foram conduzidos dois ensaios sequenciais utilizando a mesma forragem e os mesmos animais. Os animais eram seis cordeiros da raça Lacaune, mantidos em gaiolas metabólicas. No primeiro ensaio, os cordeiros receberam diariamente 1 g TiO2 em única dosagem (às 08 h 30), e no segundo foram oferecidas duas dosagens (08h30 e 16 h 30). Em ambos os ensaios, após sete dias para estabilização da excreção fecal do marcador foram realizados cinco dias de coleta total de fezes. A produção fecal observada foi comparada com a produção fecal estimada pelo TiO2, com ou sem correções, para sua taxa de recuperação fecal (kTiO2). A kTiO2 foi próxima de 1.0 e a produção fecal estimada foi similar à observada (P>0,05), independente do número de dosagens. Estes resultados mostram que o TiO2 é um indicador externo que pode ser utilizado, em única ou dupla dosagem, em experimentos com ovinos em pastejo.(AU)

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Background: Neospora caninum and Toxoplasma gondii are closely related cyst-forming apicomplexan parasites identified as important causes of reproductive failure in cattle. Moreover, abortion cases attributed to N. caninum and T. gondiiinfection have been occasionally reported in sheep. Due to the relatively scarce information on the molecular detection ofN. caninum in the semen of naturally infected rams, this study aimed to detect parasitic DNA in fresh semen samples andin frozen extended semen straws from male sheep from artificial inseminations centers in Southern Brazil.Materials, Methods & Results: Semen samples of 38 rams from artificial insemination centers were evaluated. Eleven ramswere naturally infected (seropositive for anti-N. caninum and/or anti-T. gondii IgG) and were selected for fresh semen collection.We tested all the samples for the closely related protozoan T. gondii to detect a possible cross-reaction and co-infection, due tothe close similarity with N. caninum. The indirect fluorescent antibody test was used to detect IgG antibodies in the 11 serumsamples from rams. Fresh semen samples were collected from 11 rams on days 1, 50, 55, and 58 using an artificial vaginaand ewe in estrus. Other 27 rams had their frozen extended semen straws analyzed. A total of 20 fresh semen samples and27 frozen extended semen straws samples were used to detect the presence of N. caninum and T. gondii DNA by polymerasechain reaction (PCR). Nc-5 and B1 genes were used as target regions to detect N. caninum and T. gondii DNA, respectively.The presence of N. caninum DNA was confirmed in the third collection of a fresh semen sample of one seropositive ram. T.gondii DNA was detected in a fresh semen sample of one seropositive ram. The DNA sequences of 186 bp from N. caninum(GenBank accession: MH806393) and 492 bp from T. gondii (GenBank accession: MH793503)...(AU)

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Titanium dioxide (TiO2) is an external marker used to estimate fecal output based on forage intake of grazing ruminants; however, its use as marker for grazing sheep still needs attention. In the present study the TiO2 role to estimate fecal output of sheep grazing annual ryegrass was tested. Two essays were conducted in sequence using the same forage and animals. Six lacaune lambs were housed in metabolic cages. Lambs were administered 1 g TiO2 in a single (at 8:30 am, essay 1), or in two daily doses (at 8:30 am and 4:30 pm, essay 2). In both essays the TiO2 administration was followed by a 7-day period to stabilize the fecal excretion of the marker and then by a 5-day period for total collection of feces. Observed and TiO2-based estimated fecal outputs were compared, with or without correction for TiO2 fecal recovery rate (kTiO2). The kTiO2 was around 1.0 and the estimated fecal outputs were similar to the observed ones (p>0.05), regardless the number of daily doses. These results suggested that TiO2, administered in single or two daily doses, can be used as an external marker in grazing sheep.

O dióxido de titânio (TiO2) é um marcador externo utilizado para estimativas da excreção fecal, visando medidas de consumo de forragem em ruminantes a pasto. No entanto, o uso deste marcador para ovinos em pastejo ainda pode ser melhor explorado. Neste trabalho, o TiO2 foi testado para estimar a produção fecal de ovinos ingerindo azevém anual. Foram conduzidos dois ensaios sequenciais utilizando a mesma forragem e os mesmos animais. Os animais eram seis cordeiros da raça Lacaune, mantidos em gaiolas metabólicas. No primeiro ensaio, os cordeiros receberam diariamente 1 g TiO2 em única dosagem (às 08 h 30), e no segundo foram oferecidas duas dosagens (08h30 e 16 h 30). Em ambos os ensaios, após sete dias para estabilização da excreção fecal do marcador foram realizados cinco dias de coleta total de fezes. A produção fecal observada foi comparada com a produção fecal estimada pelo TiO2, com ou sem correções, para sua taxa de recuperação fecal (kTiO2). A kTiO2 foi próxima de 1.0 e a produção fecal estimada foi similar à observada (P>0,05), independente do número de dosagens. Estes resultados mostram que o TiO2 é um indicador externo que pode ser utilizado, em única ou dupla dosagem, em experimentos com ovinos em pastejo.

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Background: Neospora caninum and Toxoplasma gondii are closely related cyst-forming apicomplexan parasites identified as important causes of reproductive failure in cattle. Moreover, abortion cases attributed to N. caninum and T. gondiiinfection have been occasionally reported in sheep. Due to the relatively scarce information on the molecular detection ofN. caninum in the semen of naturally infected rams, this study aimed to detect parasitic DNA in fresh semen samples andin frozen extended semen straws from male sheep from artificial inseminations centers in Southern Brazil.Materials, Methods & Results: Semen samples of 38 rams from artificial insemination centers were evaluated. Eleven ramswere naturally infected (seropositive for anti-N. caninum and/or anti-T. gondii IgG) and were selected for fresh semen collection.We tested all the samples for the closely related protozoan T. gondii to detect a possible cross-reaction and co-infection, due tothe close similarity with N. caninum. The indirect fluorescent antibody test was used to detect IgG antibodies in the 11 serumsamples from rams. Fresh semen samples were collected from 11 rams on days 1, 50, 55, and 58 using an artificial vaginaand ewe in estrus. Other 27 rams had their frozen extended semen straws analyzed. A total of 20 fresh semen samples and27 frozen extended semen straws samples were used to detect the presence of N. caninum and T. gondii DNA by polymerasechain reaction (PCR). Nc-5 and B1 genes were used as target regions to detect N. caninum and T. gondii DNA, respectively.The presence of N. caninum DNA was confirmed in the third collection of a fresh semen sample of one seropositive ram. T.gondii DNA was detected in a fresh semen sample of one seropositive ram. The DNA sequences of 186 bp from N. caninum(GenBank accession: MH806393) and 492 bp from T. gondii (GenBank accession: MH793503)...

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Important physiological changes affect the blood profile of ruminants during the growth phase, but few studies approach the factors involved in these dynamics in lambs. The aim of this study was to characterize the dynamics of hematological parameters, of total plasma protein (TPP), and of fibrinogen in healthy female lambs during the first four months of life. Blood samples of 35 female lambs were collected at 30, 60, 90, and 120 days old to perform the complete blood count (CBC). The erythrocyte and leukocyte parameters, TPP, and fibrinogen were determined. The means for total red blood cell (RBC) counts at 60 and 120 days differed (P < 0.05) from the initial mean, showing a peak of 13.6 x 106 cells μL-1 at 60 days old. The mean values for packed cell volume (PCV) and hemoglobin (Hgb) concentration increased (P < 0.05) until 90 days and decreased at 120 days (36.6% to 33.7% and 11.4 g dL-1 to 10.6 g dL-1 between 90 and 120 days, respectively). The means for mean corpuscular volume (MCV) and for mean corpuscular hemoglobin concentration (MCHC) increased (P < 0.05) between 30 and 120 days (27.5 μm3 to 29.7 μm3 and 26.6% to 31.4%, respectively). The total white blood cell (WBC) count increased (P < 0.05) and reached a peak at 90 days (9,314 cells μL-1). The peaks for segmented neutrophils (5,141 cells μL-1) and lymphocyte counts (4,236 cells μL-1) occurred at 60 and 90 days, respectively. The means for neutrophil/lymphocyte ratio were similar (P > 0.05) between the ages (mean of 1.8) but higher than the reference value for adult sheep (0.5). The initial mean for eosinophil counts (2 cells μL-1) was lower (P < 0.05) than all subsequent ones, and the monocyte count showed the lowest level (P < 0.05) at 120 days (232 cells μL-1). The mean for TPP at 60 days (6.4 g dL-1) was higher (P < 0.05) than the other ages.(AU)

Important physiological changes affect the blood profile of ruminants during the growth phase, but few studies approach the factors involved in these dynamics in lambs. The aim of this study was to characterize the dynamics of hematological parameters, of total plasma protein (TPP), and of fibrinogen in healthy female lambs during the first four months of life. Blood samples of 35 female lambs were collected at 30, 60, 90, and 120 days old to perform the complete blood count (CBC). The erythrocyte and leukocyte parameters, TPP, and fibrinogen were determined. The means for total red blood cell (RBC) counts at 60 and 120 days differed (P < 0.05) from the initial mean, showing a peak of 13.6 x 106 cells μL-1 at 60 days old. The mean values for packed cell volume (PCV) and hemoglobin (Hgb) concentration increased (P < 0.05) until 90 days and decreased at 120 days (36.6% to 33.7% and 11.4 g dL-1 to 10.6 g dL-1 between 90 and 120 days, respectively). The means for mean corpuscular volume (MCV) and for mean corpuscular hemoglobin concentration (MCHC) increased (P < 0.05) between 30 and 120 days (27.5 μm3 to 29.7 μm3 and 26.6% to 31.4%, respectively). The total white blood cell (WBC) count increased (P < 0.05) and reached a peak at 90 days (9,314 cells μL-1). The peaks for segmented neutrophils (5,141 cells μL-1) and lymphocyte counts (4,236 cells μL-1) occurred at 60 and 90 days, respectively. The means for neutrophil/lymphocyte ratio were similar (P > 0.05) between the ages (mean of 1.8) but higher than the reference value for adult sheep (0.5). The initial mean for eosinophil counts (2 cells μL-1) was lower (P < 0.05) than all subsequent ones, and the monocyte count showed the lowest level (P < 0.05) at 120 days (232 cells μL-1). The mean for TPP at 60 days (6.4 g dL-1) was higher (P < 0.05) than the other ages.(AU)

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RESUMO

The aim of this study was to evaluate phage display technology for mapping Haemonchus contortus mimotopes. We screened the PhD-7 Phage Display Peptide Library Kit with a sheep polyclonal antibody against H. contortus. After four rounds of selection, 50 phage peptide clones were selected by biopanning and sequenced. Two clones displaying peptide mimotopes of H. contortus proteins were chosen for sheep immunization: clone 6 - mimotope of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and clone 17 - mimotope of a disorganized muscle family member (Dim 1). Twelve sheep were allocated into 3 groups of 4 animals as follow: G1: control group; G2/GAPDH: immunized with clone 6; and G3/Dim1: immunized with clone 17. Four immunizations were performed at intervals of seven days (0, 7, 14, and 21 days). On day 28 post initial vaccination, all groups were orally challenged with 2500 H. contortus infective larvae. The mimotope peptides selected by phage display were recognized by IgG from sheep naturaly infected with H. contortus. The immunization protocol showed an increasein IgG anti-M13 phage titers, but no effect was observed in IgG-specific for the anti-mimotope peptides. This is the first report of successful use of a phage display library for the identification of mimotopes of H. contortus proteins.(AU)

O objetivo deste estudo foi avaliar a tecnologia de phage display no mapeamento de mimetopos de Haemonchus contortus. Anticorpo policlonal de ovinos anti-H. contortus foi usado para seleção a partir da biblioteca PhD-7 Phage Display Peptide Library Kit (New England BioLabs). Após quatro rodadas, 50 clones de fagos expressando peptídeos foram selecionados e sequenciados. Dois clones que exibiram mimetopos de H. contortus foram escolhidos para imunização de ovinos: clone 6 mimetopo de gliceraldeído-3-fosfato desidrogenase (GAPDH) e clone 17 - mimetopo da família do músculo desorganizado (Dim 1). Doze ovinos foram alocados em 3 grupos de 4 animais, da seguinte forma: G1: grupo controle, G2/GAPDH: imunizado com o clone 6 e G3/Dim1: imunizado com o clone 17. Quatro imunizações foram realizadas (0, 7, 14 e 21 dias). No dia 28 após a primeira imunização, todos os grupos foram desafiados oralmente com 2500 larvas infectantes de H. contortus . Os peptídeos mimetopos selecionados foram reconhecidos por IgG de ovinos naturalmente infectados por H. contortus. O ensaio de imunização revelou um aument dos títulos de IgG anti-fago M13, mas não ocorreu aumento de IgG anti-peptídeos mimetopos. Este é o primeiro relato de uso bem sucedido da biblioteca de Phage display para a identificação de mimetopos de H. contortus.(AU)

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