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Male effect in Churra Galega Bragançana and Suffolk ewes under long-day artificial photoperiod

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Resumo:This study aimed to evaluate the male effect in Churra Galega Bragançana (CGB) and Suffolk (S) ewes under artificial long-day photoperiod (16L:8D). On March 21st, 34 CGB and 27 S ewes, 2-5 years old, were allocated in light control facilities. Two months later, ovarian activity was registered by progesterone concentrations in blood plasma twice weekly. Ovarian activity was controlled by vaginal sponges (FGA). Vasectomised aproned rams were used to induce ram effect and estrus detection. Ewes were observed for estrus twice daily. Ewes presenting ovarian activity were identified by endoscopy. Chi-square tests were performed to compare proportions and Student’s t-tests to compare means of the ovulation rate. After 2 months in 16L:8D photoperiod, 81.5% of Suffolk and 64.7% of CGB ewes were in anestrous (P≤0.01). Male effect was influenced by breed (S vs. CGB) – Estrus: 50.0% vs. 75.0% (P≤0.001) and Ovulation: 18.2% vs. 63.6% (P≤0.001) –, except for ovulation rate (1.0±0.0). Data suggests that male effect is more effective in CGB than in Suffolk ewes.
Autores principais:Azevedo, Jorge
Outros Autores:Correia, Teresa Montenegro; Valentim, Ramiro; Almeida, José Carlos; Simões, João; Galvão, Lurdes; Velasco, Helena; Maurício, Raimundo; Fontes, Paulo; Mendonça, Álvaro; Cardoso, Manuel
Ano:2007
País:Portugal
Tipo de documento:documento de conferência
Tipo de acesso:acesso aberto
Instituição associada:Instituto Politécnico de Bragança
Idioma:inglês
Origem:Biblioteca Digital do IPB
Descrição
Resumo:This study aimed to evaluate the male effect in Churra Galega Bragançana (CGB) and Suffolk (S) ewes under artificial long-day photoperiod (16L:8D). On March 21st, 34 CGB and 27 S ewes, 2-5 years old, were allocated in light control facilities. Two months later, ovarian activity was registered by progesterone concentrations in blood plasma twice weekly. Ovarian activity was controlled by vaginal sponges (FGA). Vasectomised aproned rams were used to induce ram effect and estrus detection. Ewes were observed for estrus twice daily. Ewes presenting ovarian activity were identified by endoscopy. Chi-square tests were performed to compare proportions and Student’s t-tests to compare means of the ovulation rate. After 2 months in 16L:8D photoperiod, 81.5% of Suffolk and 64.7% of CGB ewes were in anestrous (P≤0.01). Male effect was influenced by breed (S vs. CGB) – Estrus: 50.0% vs. 75.0% (P≤0.001) and Ovulation: 18.2% vs. 63.6% (P≤0.001) –, except for ovulation rate (1.0±0.0). Data suggests that male effect is more effective in CGB than in Suffolk ewes.