Effects of thermal environment on dairy cattle under a grazing system in the Western Amazon, Brazil / Efeitos do ambiente térmico em bovinos leiteiros em sistema de pastejo na Amazônia Ocidental, Brasil

This study aimed to evaluate the thermal conditions to which animals are exposed and their effect on the comfort/discomfort of dairy herds in a grazing system in the municipality of Sena Madureira, Acre State, Brazil. Eight farms and a total of 113 lactating crossbred cows were evaluated. Dry-bulb temperature (DBT, °C), relative humidity (RH, %), black globe temperature (BGT, °C), and wind speed (v, km h¹) were measured in January, February, and March (rainy season) to calculate temperature-humidity index (THI), black globe-humidity index (GTWBI), and radiant heat load (RHL). Moreover, the animals were measured for the physiological variables: rectal temperature (RT), heart rate (HR), and respiratory rate (RR). Significant differences (P<0.05) were observed for THI, GTWBI, and RHL. THI reached a mean value of 80 on farm G in January. Farm F had a GTWBI value of 79 in February. RHL reached the highest value (510 W m²). RT and HR showed no differences among the analyzed months. Thus, the environmental conditions in which dairy cows are housed at milking time rarely promoted thermal discomfort, with farm G being the most affected by THI.

Objetivou-se avaliar as condições térmicas a que os animais estão submetidos, seu efeito no conforto/desconforto de rebanhos leiteiros em sistema de pastejo, no município de Sena Madureira-Acre. Foram avaliadas oito propriedades e o total de 113 vacas mestiças em lactação. As medições ocorreram nos meses: janeiro, fevereiro e março (inverno amazônico), mensurando-se: temperatura do bulbo seco (TBS, °C), umidade relativa do ar (UR, %) e temperatura de globo negro (TGN, °C), velocidade do vento (v, km/h) para cálculos dos índices da temperatura e umidade (ITU), índice da temperatura de globo e umidade (ITGU) e carga térmica radiante (CTR), além da temperatura retal (TR), frequência cardíaca (FC), frequência respiratória (FR). Entre as propriedades analisadas, houve diferenças significativas (P<0,05) para ITU, ITGU e CTR. Destaca-se que o ITU na propriedade G, em janeiro, atingiu o valor médio de 80. A propriedade F, em fevereiro, teve valor de 79 para o ITGU. A CTR apresentou carga elevada (510 W.m³). A TR e a FC não apresentaram diferença entre os meses analisados. Concluiu-se que o ambiente ao qual as vacas leiteiras estão alojadas na hora da ordenha encontraram-se poucas vezes em situação de desconforto térmico, sendo a propriedade, a mais afetada pelo ITU.

The effects of weather on milk production in dairy sheep vary by month of lambing and lactation phase

A total number of 609 bulk-tank milk controls on a dairy sheep farm in Spain were used to determine how weather affects milk production in sheep, related to lambing period and lactation phase. Data from individuals were assigned to one of five lactation periods based on the timing of lambing: FEB (n=124); APR (n=141); JUL (n=114); SEP (n=102), and NOV (n=128). Milk yield per ewe per day was calculated as total milk volume/number of ewes milked. Lactation was divided into three phases: Early-lactation (from lambing to month 2), Mid-lactation (from month 3 to 7), and Late-lactation (month 8). Milk yield per ewe was higher (P<0.01) in SEP than in FEB, APR, or NOV; production peaked in JUL and was lowest in FEB. In lactations initiated in JUL and SEP, milk yield per ewe per day was higher (P<0.05) in early lactation than it was in the other lambing periods; however, in APR and SEP, per ewe production was highest (P<0.01) in mid-lactation. Milk yield in each of the five lambing periods was significantly (P=0.001) associated with several meteorological variables, and the strongest (R2 =0.732) was with solar radiation and minimum temperature in the APR lactation period. In all lactation periods, the relationship between milk yield and weather differed among the three phases of lactation. In conclusion, the effects of meteorological conditions on milk yield in sheep cannot be understood without assessing production among milking periods in the same year and the phases of lactation, especially if milking periods are long.(AU)

The effects of weather on milk production in dairy sheep vary by month of lambing and lactation phase

A total number of 609 bulk-tank milk controls on a dairy sheep farm in Spain were used to determine how weather affects milk production in sheep, related to lambing period and lactation phase. Data from individuals were assigned to one of five lactation periods based on the timing of lambing: FEB (n=124); APR (n=141); JUL (n=114); SEP (n=102), and NOV (n=128). Milk yield per ewe per day was calculated as total milk volume/number of ewes milked. Lactation was divided into three phases: Early-lactation (from lambing to month 2), Mid-lactation (from month 3 to 7), and Late-lactation (month 8). Milk yield per ewe was higher (P<0.01) in SEP than in FEB, APR, or NOV; production peaked in JUL and was lowest in FEB. In lactations initiated in JUL and SEP, milk yield per ewe per day was higher (P<0.05) in early lactation than it was in the other lambing periods; however, in APR and SEP, per ewe production was highest (P<0.01) in mid-lactation. Milk yield in each of the five lambing periods was significantly (P=0.001) associated with several meteorological variables, and the strongest (R2 =0.732) was with solar radiation and minimum temperature in the APR lactation period. In all lactation periods, the relationship between milk yield and weather differed among the three phases of lactation. In conclusion, the effects of meteorological conditions on milk yield in sheep cannot be understood without assessing production among milking periods in the same year and the phases of lactation, especially if milking periods are long.

Flutuação populacional e estimativa do número de gerações de Anastrepha fraterculus (Diptera: Tephritidae) em pomar de macieira em Caçador, Santa Catarina, Brasil / Population fluctuation and estimate of generations number of Anastrepha fraterculus (Diptera: Tephritidae) in apple orchard in Caçador, Santa Catarina, Brazil

This study aimed to evaluated the population fluctuation and estimate the number of Anastrepha fraterculus (Diptera: Tephritidae) generations per year, based on meteorological variables in Caçador, SC, Brazil. The work was carried out in an organic apple orchard from October/2009 to April/2012. The fruit flies numbers were weekly recorded with four McPhail traps baited with Torula®. The association between the number of adults captured and meteorological variables (maximum, average and minimum temperatures, rainfall and relative humidity) was calculated using Pearsons correlation coefficient (p 0.05). In off-season crop (May to September), the daily average of the meteorological variables were evaluated calculated by F or Kruskal-Wallis tests (p 0.05). The number of generations per year was estimated based on minimum temperature from 2009 to 2012, thermal constant and basal temperature, established for A. fraterculus. The South American fruit fly occurred from November to April, with population peaks in January or February. We observed, only in 2010/2011 crop season, correlation between average number of adults captured and maximum, average and minimum temperatures. It was estimated that may occur about eight A. fraterculus generations per year in Caçador, Santa Catarina.

Este estudo teve como objetivos avaliar a flutuação populacional e estimar o número de gerações por ano de Anastrepha fraterculus (Diptera: Tephritidae), com base nas variáveis meteorológicas de Caçador, Santa Catarina, Brasil. O estudo foi conduzido em pomar orgânico de macieira, de outubro de 2009 a abril de 2012. O número de moscas-das-frutas foi aferido semanalmente, com quatro armadilhas do tipo McPhail iscadas com Torula®. A associação entre o número de adultos capturados e as variáveis meteorológicas (temperaturas máxima, mínima e média, precipitação pluviométrica e umidade relativa do ar) foi feita pelo coeficiente de correlação de Pearson (p 0,05). Para o período de entressafra (maio a setembro), os valores médios diários das variáveis meteorológicas foram calculados pelos testes F ou de Kruskal-Wallis (p 0,05). O número de gerações/ano foi estimado utilizando-se os dados de temperatura mínima de 2009 até 2012, constante térmica e temperatura basal estabelecidos para A. fraterculus. Verificou-se que a mosca-das-frutas sul-americana ocorreu de novembro a abril, com picos populacionais em janeiro ou fevereiro. Apenas na safra 2010/2011 houve correlação entre o número médio de adultos capturados e as temperaturas máxima, média e mínima. Estimou-se que podem ocorrer em torno de oito gerações de A. fraterculus por ano em Caçador, Santa Catarina.

Flutuação populacional e estimativa do número de gerações de Anastrepha fraterculus (Diptera: Tephritidae) em pomar de macieira em Caçador, Santa Catarina, Brasil / Population fluctuation and estimate of generations number of Anastrepha fraterculus (Diptera: Tephritidae) in apple orchard in Caçador, Santa Catarina, Brazil

Este estudo teve como objetivos avaliar a flutuação populacional e estimar o número de gerações por ano de Anastrepha fraterculus (Diptera: Tephritidae), com base nas variáveis meteorológicas de Caçador, Santa Catarina, Brasil. O estudo foi conduzido em pomar orgânico de macieira, de outubro de 2009 a abril de 2012. O número de moscas-das-frutas foi aferido semanalmente, com quatro armadilhas do tipo McPhail iscadas com Torula®. A associação entre o número de adultos capturados e as variáveis meteorológicas (temperaturas máxima, mínima e média, precipitação pluviométrica e umidade relativa do ar) foi feita pelo coeficiente de correlação de Pearson (p < 0,05). Para o período de entressafra (maio a setembro), os valores médios diários das variáveis meteorológicas foram calculados pelos testes F ou de Kruskal-Wallis (p < 0,05). O número de gerações/ano foi estimado utilizando-se os dados de temperatura mínima de 2009 até 2012, constante térmica e temperatura basal estabelecidos para A. fraterculus. Verificou-se que a mosca-das-frutas sul-americana ocorreu de novembro a abril, com picos populacionais em janeiro ou fevereiro. Apenas na safra 2010/2011 houve correlação entre o número médio de adultos capturados e as temperaturas máxima, média e mínima. Estimou-se que podem ocorrer em torno de oito gerações de A. fraterculus por ano em Caçador, Santa Catarina.(AU)

This study aimed to evaluated the population fluctuation and estimate the number of Anastrepha fraterculus (Diptera: Tephritidae) generations per year, based on meteorological variables in Caçador, SC, Brazil. The work was carried out in an organic apple orchard from October/2009 to April/2012. The fruit flies numbers were weekly recorded with four McPhail traps baited with Torula®. The association between the number of adults captured and meteorological variables (maximum, average and minimum temperatures, rainfall and relative humidity) was calculated using Pearson's correlation coefficient (p < 0.05). In off-season crop (May to September), the daily average of the meteorological variables were evaluated calculated by F or Kruskal-Wallis tests (p < 0.05). The number of generations per year was estimated based on minimum temperature from 2009 to 2012, thermal constant and basal temperature, established for A. fraterculus. The South American fruit fly occurred from November to April, with population peaks in January or February. We observed, only in 2010/2011 crop season, correlation between average number of adults captured and maximum, average and minimum temperatures. It was estimated that may occur about eight A. fraterculus generations per year in Caçador, Santa Catarina.(AU)

Flutuação populacional e estimativa do número de gerações de Anastrepha fraterculus (Diptera: Tephritidae) em pomar de macieira em Caçador, Santa Catarina, Brasil / Population fluctuation and estimate of generations number of Anastrepha fraterculus (Diptera: Tephritidae) in apple orchard in Caçador, Santa Catarina, Brazil

This study aimed to evaluated the population fluctuation and estimate the number of Anastrepha fraterculus (Diptera: Tephritidae) generations per year, based on meteorological variables in Caçador, SC, Brazil. The work was carried out in an organic apple orchard from October/2009 to April/2012. The fruit flies numbers were weekly recorded with four McPhail traps baited with Torula®. The association between the number of adults captured and meteorological variables (maximum, average and minimum temperatures, rainfall and relative humidity) was calculated using Pearsons correlation coefficient (p 0.05). In off-season crop (May to September), the daily average of the meteorological variables were evaluated calculated by F or Kruskal-Wallis tests (p 0.05). The number of generations per year was estimated based on minimum temperature from 2009 to 2012, thermal constant and basal temperature, established for A. fraterculus. The South American fruit fly occurred from November to April, with population peaks in January or February. We observed, only in 2010/2011 crop season, correlation between average number of adults captured and maximum, average and minimum temperatures. It was estimated that may occur about eight A. fraterculus generations per year in Caçador, Santa Catarina.(AU)

Este estudo teve como objetivos avaliar a flutuação populacional e estimar o número de gerações por ano de Anastrepha fraterculus (Diptera: Tephritidae), com base nas variáveis meteorológicas de Caçador, Santa Catarina, Brasil. O estudo foi conduzido em pomar orgânico de macieira, de outubro de 2009 a abril de 2012. O número de moscas-das-frutas foi aferido semanalmente, com quatro armadilhas do tipo McPhail iscadas com Torula®. A associação entre o número de adultos capturados e as variáveis meteorológicas (temperaturas máxima, mínima e média, precipitação pluviométrica e umidade relativa do ar) foi feita pelo coeficiente de correlação de Pearson (p 0,05). Para o período de entressafra (maio a setembro), os valores médios diários das variáveis meteorológicas foram calculados pelos testes F ou de Kruskal-Wallis (p 0,05). O número de gerações/ano foi estimado utilizando-se os dados de temperatura mínima de 2009 até 2012, constante térmica e temperatura basal estabelecidos para A. fraterculus. Verificou-se que a mosca-das-frutas sul-americana ocorreu de novembro a abril, com picos populacionais em janeiro ou fevereiro. Apenas na safra 2010/2011 houve correlação entre o número médio de adultos capturados e as temperaturas máxima, média e mínima. Estimou-se que podem ocorrer em torno de oito gerações de A. fraterculus por ano em Caçador, Santa Catarina.(AU)