Indicadores fisiológicos, desempenho, rendimentos ao abate e qualidade de carne de coelhos puros e mestiços submetidos ao estresse pelo calor intenso ou moderado
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Data
2009-02-11
Autores
Zeferino , Cynthia Pieri [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo foi avaliar os efeitos da interação grupo genético x estresse pelo calor sobre indicadores fisiológicos e desempenho de coelhos em crescimento. Foram utilizados 96 coelhos desmamados, metade do grupo genético Botucatu e metade mestiça, produtos do cruzamento entre machos da raça Nova Zelândia Branca e fêmeas Botucatu. Os animais foram distribuídos num delineamento inteiramente casualizado, com arranjo fatorial 2 x 3 (grupos genéticos e condições térmicas: termoneutra, estresse moderado e intenso) com medidas repetidas (semanas). A temperatura retal e da superfície da pele e a freqüência respiratória foram registradas entre 42 e 67 dias de idade enquanto o peso vivo e o consumo de ração foram registrados dos 35 até os 70 dias de idade. A temperatura e a umidade relativa do ar média foram 18,4°C e 63,9% (termoneutralidade), 24,4°C e 80,2% (estresse moderado) e 29,6°C e 75,9% (estresse intenso). Observou-se queda na temperatura retal com o tempo, cuja intensidade variou com a condição térmica, mas na última semana houve aumento acentuado sob estresse intenso. Verificou-se relação direta entre temperatura média da superfície da pele e temperatura ambiente, mas houve pequenas diferenças entre os grupos genéticos nas semanas. A temperatura das orelhas se elevou até a oitava semana; na nona semana sofreu redução nos dois grupos genéticos, mas esta foi mais pronunciada nos coelhos puros. A freqüência respiratória e a temperatura das orelhas se elevaram proporcionalmente ao nível de estresse pelo calor com o tempo, mas esta tendência não foi uniforme nas três condições térmicas. A freqüência respiratória aumentou com o tempo nos dois grupos genéticos, mas o aumento foi mais pronunciado nos coelhos puros. Em condições de estresse intenso, o peso vivo e o consumo de alimento dos coelhos puros superaram os dos mestiços...
The objective was to evaluate the effects of the interaction between genetic group (straightbred or crossbred) and heat stress (intense or moderate) on physiological indicators and performance of growing rabbits. Ninety-six weaned rabbits were used; half were from the Botucatu genetic group and half were crossbreds between New Zealand White males and Botucatu females. They were assigned to a completely randomized design in a 2 x 3 factorial arrangement (genetic groups and thermal conditions: thermoneutral, moderate and intense heat stress) with repeated measures (weeks). The rectal temperature, skin surface temperature and respiratory frequency were recorded from 42 to 67 days of age, whereas body weight and feed intake were recorded from 35 up to 70 days of age. Average ambient temperature and relative humidity were 18.4°C and 63.9% (thermoneutral), 24.4°C and 80.2% (moderate heat stress) and 29.6°C and 75.9% (intense heat stress). A decrease in rectal temperature over time was observed whose intensity was distinct according to the thermal condition but, in the last week, there was a sudden increase under intense heat stress. There was a direct relationship between average skin temperature and ambient temperature, but there were slight differences between the genetic groups over weeks. Ear temperature increased up to the eighth week; in the ninth week it decreased in both genetic groups, but the decrease was more pronounced in the straightbreds. Respiratory frequency and ear temperature increased with heat stress over time, but this trend was not uniform across all thermal conditions. Respiratory frequency also showed an elevation trend over weeks in both genetic groups, but it was more pronounced in the straightbreds. Under heat stress conditions, body weight and feed intake of the straightbreds were higher than those of the crossbreds, but under moderate heat stress... (Complete abstract click electronic access below)
The objective was to evaluate the effects of the interaction between genetic group (straightbred or crossbred) and heat stress (intense or moderate) on physiological indicators and performance of growing rabbits. Ninety-six weaned rabbits were used; half were from the Botucatu genetic group and half were crossbreds between New Zealand White males and Botucatu females. They were assigned to a completely randomized design in a 2 x 3 factorial arrangement (genetic groups and thermal conditions: thermoneutral, moderate and intense heat stress) with repeated measures (weeks). The rectal temperature, skin surface temperature and respiratory frequency were recorded from 42 to 67 days of age, whereas body weight and feed intake were recorded from 35 up to 70 days of age. Average ambient temperature and relative humidity were 18.4°C and 63.9% (thermoneutral), 24.4°C and 80.2% (moderate heat stress) and 29.6°C and 75.9% (intense heat stress). A decrease in rectal temperature over time was observed whose intensity was distinct according to the thermal condition but, in the last week, there was a sudden increase under intense heat stress. There was a direct relationship between average skin temperature and ambient temperature, but there were slight differences between the genetic groups over weeks. Ear temperature increased up to the eighth week; in the ninth week it decreased in both genetic groups, but the decrease was more pronounced in the straightbreds. Respiratory frequency and ear temperature increased with heat stress over time, but this trend was not uniform across all thermal conditions. Respiratory frequency also showed an elevation trend over weeks in both genetic groups, but it was more pronounced in the straightbreds. Under heat stress conditions, body weight and feed intake of the straightbreds were higher than those of the crossbreds, but under moderate heat stress... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Coelho - Efeito de stress, Carne - Qualidade, Crescimento, Growth, Respiratory frequency, Genetic group, Temperature, Thermoneutrality
Como citar
ZEFERINO , Cynthia Pieri. Indicadores fisiológicos, desempenho, rendimentos ao abate e qualidade de carne de coelhos puros e mestiços submetidos ao estresse pelo calor intenso ou moderado. 2009. viii, 81 f. Dissertação (mestrado) - Univerdade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia de Botucatu, 2009.