Growth and reproduction hormones of ruminants subjected to heat stress

The adaptation of the animals, either temperate or tropical climate, is mainly related to physiology and its adaptation to the environment. When subjected to temperature and humidity different from the usual air, these animals found in heat stress difficulty reproduction and production. The endocrine system is one of those responsible for controlling the stress response, and rapid and appropriate growth is one of the elements of greatest economic importance toward meat production, and more producers want to improve, to accelerate the production rate and decreasing production costs. Thus, the aim of this review was to evaluate, through research papers found in the literature, the influence of heat stress on the hormones of growth and reproduction in ruminants. It was observed that even in studies that do not consider the productive performance of the animals, the influence of these parameters is significant in the ambience and the degree of adaptation of the same. However, more research should be conducted in order to evaluate the production of animals of different species under the conditions of different regions, as well as search for alternatives to achieve the best animal production levels, either by finding the best way of introducing exotic breeds, or the possibility of bringing more comfort to the animals in their various productive and reproductive stages.(AU)

Growth and reproduction hormones of ruminants subjected to heat stress

The adaptation of the animals, either temperate or tropical climate, is mainly related to physiology and its adaptation to the environment. When subjected to temperature and humidity different from the usual air, these animals found in heat stress difficulty reproduction and production. The endocrine system is one of those responsible for controlling the stress response, and rapid and appropriate growth is one of the elements of greatest economic importance toward meat production, and more producers want to improve, to accelerate the production rate and decreasing production costs. Thus, the aim of this review was to evaluate, through research papers found in the literature, the influence of heat stress on the hormones of growth and reproduction in ruminants. It was observed that even in studies that do not consider the productive performance of the animals, the influence of these parameters is significant in the ambience and the degree of adaptation of the same. However, more research should be conducted in order to evaluate the production of animals of different species under the conditions of different regions, as well as search for alternatives to achieve the best animal production levels, either by finding the best way of introducing exotic breeds, or the possibility of bringing more comfort to the animals in their various productive and reproductive stages.

Leptospirosis in native mixed-breed sheep slaughtered in a semiarid region of Brazil / Leptospirose em ovinos mestiços abatidos em uma região semiárida do Brasil

Sheep breeding is an economic activity of great value for the Brazilian livestock industry, and infectious diseases can significantly compromise its productivity. The aim of this study was to detect Leptospira spp. in mixed breed sheep from a semiarid region of the State of ParaМba, Northeast Brazil. In total, 49 blood and renal tissue samples, as well as 25 urine samples, were collected from 49 sheep in the slaughter line. The microscopic agglutination test (MAT) was used to verify the presence of anti -Leptospira spp. antibodies in blood samples. Renal tissue and urine samples were analyzed by both PCR and bacterial culture. Sero reactivity was observed in 8.2% (4/49) of animals. Three renal samples were positive for leptospiral DNA by PCR although all urine samples were negative. No leptospires in pure culture were recovered from the samples tested. Low prevalence of Leptospira spp. observed by serology and PCR suggested that the rusticity of the mixed-breed sheep may have contributed to the low occurrence of leptospirosis in the semiarid region investigated.

A criação de ovinos é uma atividade econômica de grande valor para a indústria pecuária brasileira. As doenças infecciosas podem comprometer significativamente a sua produtividade. O objetivo deste estudo foi detectar Leptospira spp. em ovinos sem raça definida a partir de uma região semiárida do estado da Paraíba, Nordeste do Brasil. Quarenta e nove amostras de sangue e tecido renal, bem como amostras de urina, de 25 das 49 ovelhas, foram coletados na linha de abate. A presença de anticorpos anti -Leptospira spp. foi verificada com o teste de aglutinação microscópica (SAM). As amostras de urina e rins foram processadas por PCR e cultura bacteriológica. Sororreatividade foi observada em 8,2% (4/49) dos animais. Em relação à PCR, três amostras renais foram positivas, no entanto, todas as amostras de urina foram negativas. Nenhuma cultura pura de leptospiras foi recuperada a partir das amostras testadas. Levando em consideração a baixa frequência de positividade na sorologia e PCR, é possível sugerir que a rusticidade das ovelhas de raças mestiças colaborou para a baixa ocorrência de leptospirose na região semiárida investigada.

Leptospirosis in native mixed-breed sheep slaughtered in a semiarid region of Brazil / Leptospirose em ovinos mestiços abatidos em uma região semiárida do Brasil

Sheep breeding is an economic activity of great value for the Brazilian livestock industry, and infectious diseases can significantly compromise its productivity. The aim of this study was to detect Leptospira spp. in mixed breed sheep from a semiarid region of the State of ParaМba, Northeast Brazil. In total, 49 blood and renal tissue samples, as well as 25 urine samples, were collected from 49 sheep in the slaughter line. The microscopic agglutination test (MAT) was used to verify the presence of anti -Leptospira spp. antibodies in blood samples. Renal tissue and urine samples were analyzed by both PCR and bacterial culture. Sero reactivity was observed in 8.2% (4/49) of animals. Three renal samples were positive for leptospiral DNA by PCR although all urine samples were negative. No leptospires in pure culture were recovered from the samples tested. Low prevalence of Leptospira spp. observed by serology and PCR suggested that the rusticity of the mixed-breed sheep may have contributed to the low occurrence of leptospirosis in the semiarid region investigated. (AU)

A criação de ovinos é uma atividade econômica de grande valor para a indústria pecuária brasileira. As doenças infecciosas podem comprometer significativamente a sua produtividade. O objetivo deste estudo foi detectar Leptospira spp. em ovinos sem raça definida a partir de uma região semiárida do estado da Paraíba, Nordeste do Brasil. Quarenta e nove amostras de sangue e tecido renal, bem como amostras de urina, de 25 das 49 ovelhas, foram coletados na linha de abate. A presença de anticorpos anti -Leptospira spp. foi verificada com o teste de aglutinação microscópica (SAM). As amostras de urina e rins foram processadas por PCR e cultura bacteriológica. Sororreatividade foi observada em 8,2% (4/49) dos animais. Em relação à PCR, três amostras renais foram positivas, no entanto, todas as amostras de urina foram negativas. Nenhuma cultura pura de leptospiras foi recuperada a partir das amostras testadas. Levando em consideração a baixa frequência de positividade na sorologia e PCR, é possível sugerir que a rusticidade das ovelhas de raças mestiças colaborou para a baixa ocorrência de leptospirose na região semiárida investigada. (AU)

Leptospirosis in native mixed-breed sheep slaughtered in a semiarid region of Brazil

ABSTRACT: Sheep breeding is an economic activity of great value for the Brazilian livestock industry, and infectious diseases can significantly compromise its productivity. The aim of this study was to detect Leptospira spp. in mixed breed sheep from a semiarid region of the State of Paraíba, Northeast Brazil. In total, 49 blood and renal tissue samples, as well as 25 urine samples, were collected from 49 sheep in the slaughter line. The microscopic agglutination test (MAT) was used to verify the presence of anti -Leptospira spp. antibodies in blood samples. Renal tissue and urine samples were analyzed by both PCR and bacterial culture. Sero reactivity was observed in 8.2% (4/49) of animals. Three renal samples were positive for leptospiral DNA by PCR although all urine samples were negative. No leptospires in pure culture were recovered from the samples tested. Low prevalence of Leptospira spp. observed by serology and PCR suggested that the rusticity of the mixed-breed sheep may have contributed to the low occurrence of leptospirosis in the semiarid region investigated.

RESUMO: A criação de ovinos é uma atividade econômica de grande valor para a indústria pecuária brasileira. As doenças infecciosas podem comprometer significativamente a sua produtividade. O objetivo deste estudo foi detectar Leptospira spp. em ovinos sem raça definida a partir de uma região semiárida do estado da Paraíba, Nordeste do Brasil. Quarenta e nove amostras de sangue e tecido renal, bem como amostras de urina, de 25 das 49 ovelhas, foram coletados na linha de abate. A presença de anticorpos anti -Leptospira spp. foi verificada com o teste de aglutinação microscópica (SAM). As amostras de urina e rins foram processadas por PCR e cultura bacteriológica. Sororreatividade foi observada em 8,2% (4/49) dos animais. Em relação à PCR, três amostras renais foram positivas, no entanto, todas as amostras de urina foram negativas. Nenhuma cultura pura de leptospiras foi recuperada a partir das amostras testadas. Levando em consideração a baixa frequência de positividade na sorologia e PCR, é possível sugerir que a rusticidade das ovelhas de raças mestiças colaborou para a baixa ocorrência de leptospirose na região semiárida investigada.

Serological study of the Leptospira spp. infection in sheep and goats slaughtered in the State of Paraíba, semiarid of Northeastern Brazil / Estudo sorológico da infecção por Leptospira spp. em caprinos e ovinos abatidos no Estado da Paraíba, semiárido do Nordeste, Brasil

The aim of this survey was to determine the frequency of anti-Leptospira spp. antibodies in goats and sheep slaughtered in different slaughterhouses in the State of Paraiba, in the semi-arid region of Northeastern Brazil. Blood samples were collected from 500 goats and 500 sheep randomly selected. To verify the presence of anti-Leptospira spp. antibodies the microscopic agglutination test (MAT), using 24 serovars as antigens, was used. From the 1,000 animals analyzed, 82 (8.2%; 95% CI = 7.0%-10.5%) were sero-reactive being 26/500 (5.2%; 95% CI = 3.5%-7.5%) in goats and 56/500 (11.2%; 95% CI = 8.7%-14.2%) in sheep. The most frequent serovars were Hardjobovis (14.6%) and Autumnalis (13.4%). In goats, the most frequent serovar was the Hardjobovis, and in sheep the Ballum, with frequencies of 19.2% and 17.9%, respectively. There was a significant difference in the frequency of positive animals among slaughterhouses, both for goats (p = 0.035) and for sheep (p = 0.004), with the county of Alhandra presenting the highest frequency of seropositive animals for both species. It is concluded that sheep and goats from the semiarid region of the Northeastern Brazil may have become adapted to the serovars Hardjobovis e Autumnalis, as well as wild rodents may be involved in the transmission of the disease. It is possible that the climatic conditions influenced in the transmissibility of the leptospirosis, especially in the Mata Paraibana mesoregion, however it was not considered as being sufficient to justify the low frequency of seropositive animals. In this way, it is possible to suggest the hypothesis that the rusticity of the small ruminants in the studied region contributed to the low sero-reactivity verified.(AU)

O objetivo deste estudo foi determinar a frequência de anticorpos anti-Leptospira spp. em caprinos e ovinos abatidos em diferentes matadouros no Estado da Paraíba, região semiárida do Nordeste brasileiro. Foi coletado sangue de 500 caprinos e 500 ovinos aleatoriamente selecionados. Para verificar a presença de anticorpos anti-Leptospira spp. empregou-se o teste soroaglutinação microscópica (SAM), utilizando-se 24 sorovares como antígenos. Dos 1.000 animais analisados 82 (8,2%; IC 95%= 7,0%-10,5%) foram sororreagentes, sendo 26/500 (5,2%; IC 95% =3,5%-7,5%) em caprinos e 56/500 (11,2%; IC 95% 8,7%-14,2%) em ovinos. Os sorovares mais frequentes foram Hardjobovis (14,6%) e Autumnalis (13,4%). Na espécie caprina, o sorovar mais frequente foi o Hardjobovis, e na espécie ovina o Ballum, com frequências de 19,2% e 17,9%, respectivamente. Houve diferença significativa na frequência de positivos entre os matadouros, tanto para caprinos (p = 0,035) quanto para ovinos (p = 0,004), com o município de Alhandra apresentando a maior frequência de soropositivos para ambas as espécies. Concluiu-se que ovinos e caprinos da região semiárida do Nordeste podem estar adaptados aos sorovares Hardjobovis e Autumnalis, bem como roedores silvestres estarem envolvidos na transmissão do agente. Possivelmente as condições climáticas influenciaram a transmissibilidade da leptospirose, especialmente na mesorregião da Mata Paraibana, entretanto isso não foi considerado suficiente para justificar a baixa frequência de animais soropositivos. Deste modo, é possível sugerir a hipótese de que a rusticidade dos pequenos ruminantes na região estudada contribui para a baixa sororreatividade verificada.(AU)

Serological study of the Leptospira spp. infection in sheep and goats slaughtered in the State of Paraíba, semiarid of Northeastern Brazil / Estudo sorológico da infecção por Leptospira spp. em caprinos e ovinos abatidos no Estado da Paraíba, semiárido do Nordeste, Brasil

The aim of this survey was to determine the frequency of anti-Leptospira spp. antibodies in goats and sheep slaughtered in different slaughterhouses in the State of Paraiba, in the semi-arid region of Northeastern Brazil. Blood samples were collected from 500 goats and 500 sheep randomly selected. To verify the presence of anti-Leptospira spp. antibodies the microscopic agglutination test (MAT), using 24 serovars as antigens, was used. From the 1,000 animals analyzed, 82 (8.2%; 95% CI = 7.0%-10.5%) were sero-reactive being 26/500 (5.2%; 95% CI = 3.5%-7.5%) in goats and 56/500 (11.2%; 95% CI = 8.7%-14.2%) in sheep. The most frequent serovars were Hardjobovis (14.6%) and Autumnalis (13.4%). In goats, the most frequent serovar was the Hardjobovis, and in sheep the Ballum, with frequencies of 19.2% and 17.9%, respectively. There was a significant difference in the frequency of positive animals among slaughterhouses, both for goats (p = 0.035) and for sheep (p = 0.004), with the county of Alhandra presenting the highest frequency of seropositive animals for both species. It is concluded that sheep and goats from the semiarid region of the Northeastern Brazil may have become adapted to the serovars Hardjobovis e Autumnalis, as well as wild rodents may be involved in the transmission of the disease. It is possible that the climatic conditions influenced in the transmissibility of the leptospirosis, especially in the Mata Paraibana mesoregion, however it was not considered as being sufficient to justify the low frequency of seropositive animals. In this way, it is possible to suggest the hypothesis that the rusticity of the small ruminants in the studied region contributed to the low sero-reactivity verified.

O objetivo deste estudo foi determinar a frequência de anticorpos anti-Leptospira spp. em caprinos e ovinos abatidos em diferentes matadouros no Estado da Paraíba, região semiárida do Nordeste brasileiro. Foi coletado sangue de 500 caprinos e 500 ovinos aleatoriamente selecionados. Para verificar a presença de anticorpos anti-Leptospira spp. empregou-se o teste soroaglutinação microscópica (SAM), utilizando-se 24 sorovares como antígenos. Dos 1.000 animais analisados 82 (8,2%; IC 95%= 7,0%-10,5%) foram sororreagentes, sendo 26/500 (5,2%; IC 95% =3,5%-7,5%) em caprinos e 56/500 (11,2%; IC 95% 8,7%-14,2%) em ovinos. Os sorovares mais frequentes foram Hardjobovis (14,6%) e Autumnalis (13,4%). Na espécie caprina, o sorovar mais frequente foi o Hardjobovis, e na espécie ovina o Ballum, com frequências de 19,2% e 17,9%, respectivamente. Houve diferença significativa na frequência de positivos entre os matadouros, tanto para caprinos (p = 0,035) quanto para ovinos (p = 0,004), com o município de Alhandra apresentando a maior frequência de soropositivos para ambas as espécies. Concluiu-se que ovinos e caprinos da região semiárida do Nordeste podem estar adaptados aos sorovares Hardjobovis e Autumnalis, bem como roedores silvestres estarem envolvidos na transmissão do agente. Possivelmente as condições climáticas influenciaram a transmissibilidade da leptospirose, especialmente na mesorregião da Mata Paraibana, entretanto isso não foi considerado suficiente para justificar a baixa frequência de animais soropositivos. Deste modo, é possível sugerir a hipótese de que a rusticidade dos pequenos ruminantes na região estudada contribui para a baixa sororreatividade verificada.