ABSTRACT
Background: Complete isolation of genders allows intense estrous induction and synchronization once rams are introduced in ewe flocks at the onset of the breeding season (BS). This management practice, defined as the male effect, results from a neuroendocrine process mediated by pheromones. The male effect is a straightforward procedure to induce estrous in noncycling ewes, but conditions for its use have not been fully explored. Thus, this study aimed to evaluate hormone levels and ovarian activity of postpartum ewes in anestrus which are subjected to the male effect under different male to female ratios.Material, Methods & Results: Pospartum females were selected according to body condition score and cyclicity status. Females were kept apart from males during 30 days at a distance of 10 m. Anestrus and ovulation were determined by P4 measures on days 10, 20 and 30 after isolation from males. After P4 concentration diagnosis, anestrus ewe (n = 99) were subjected to male to ewe ratios (MFR) of 1:20 (MFR20), 1:30 (MFR30) and 1:40 (MFR40). Santa Inês rams (n = 3) of proven fertility were used. Three females of each group were randomly subjected to blood collection for LH concentration analysis. Ovarian activity was performed by ultrasonography after estrus manifestation in six ewe of each group. Estrus events were observed twice a day during the BS of 35 days, and estrus wer
ABSTRACT
Background: Complete isolation of genders allows intense estrous induction and synchronization once rams are introduced in ewe flocks at the onset of the breeding season (BS). This management practice, defined as the male effect, results from a neuroendocrine process mediated by pheromones. The male effect is a straightforward procedure to induce estrous in noncycling ewes, but conditions for its use have not been fully explored. Thus, this study aimed to evaluate hormone levels and ovarian activity of postpartum ewes in anestrus which are subjected to the male effect under different male to female ratios.Material, Methods & Results: Pospartum females were selected according to body condition score and cyclicity status. Females were kept apart from males during 30 days at a distance of 10 m. Anestrus and ovulation were determined by P4 measures on days 10, 20 and 30 after isolation from males. After P4 concentration diagnosis, anestrus ewe (n = 99) were subjected to male to ewe ratios (MFR) of 1:20 (MFR20), 1:30 (MFR30) and 1:40 (MFR40). Santa Inês rams (n = 3) of proven fertility were used. Three females of each group were randomly subjected to blood collection for LH concentration analysis. Ovarian activity was performed by ultrasonography after estrus manifestation in six ewe of each group. Estrus events were observed twice a day during the BS of 35 days, and estrus wer
ABSTRACT
Background: Complete isolation of genders allows intense estrous induction and synchronization once rams are introduced in ewe flocks at the onset of the breeding season (BS). This management practice, defined as the male effect, results from a neuroendocrine process mediated by pheromones. The male effect is a straightforward procedure to induce estrous in noncycling ewes, but conditions for its use have not been fully explored. Thus, this study aimed to evaluate hormone levels and ovarian activity of postpartum ewes in anestrus which are subjected to the male effect under different male to female ratios.Material, Methods & Results: Pospartum females were selected according to body condition score and cyclicity status. Females were kept apart from males during 30 days at a distance of 10 m. Anestrus and ovulation were determined by P4 measures on days 10, 20 and 30 after isolation from males. After P4 concentration diagnosis, anestrus ewe (n = 99) were subjected to male to ewe ratios (MFR) of 1:20 (MFR20), 1:30 (MFR30) and 1:40 (MFR40). Santa Inês rams (n = 3) of proven fertility were used. Three females of each group were randomly subjected to blood collection for LH concentration analysis. Ovarian activity was performed by ultrasonography after estrus manifestation in six ewe of each group. Estrus events were observed twice a day during the BS of 35 days, and estrus wer
ABSTRACT
Background: Complete isolation of genders allows intense estrous induction and synchronization once rams are introduced in ewe flocks at the onset of the breeding season (BS). This management practice, defined as the male effect, results from a neuroendocrine process mediated by pheromones. The male effect is a straightforward procedure to induce estrous in noncycling ewes, but conditions for its use have not been fully explored. Thus, this study aimed to evaluate hormone levels and ovarian activity of postpartum ewes in anestrus which are subjected to the male effect under different male to female ratios.Material, Methods & Results: Pospartum females were selected according to body condition score and cyclicity status. Females were kept apart from males during 30 days at a distance of 10 m. Anestrus and ovulation were determined by P4 measures on days 10, 20 and 30 after isolation from males. After P4 concentration diagnosis, anestrus ewe (n = 99) were subjected to male to ewe ratios (MFR) of 1:20 (MFR20), 1:30 (MFR30) and 1:40 (MFR40). Santa Inês rams (n = 3) of proven fertility were used. Three females of each group were randomly subjected to blood collection for LH concentration analysis. Ovarian activity was performed by ultrasonography after estrus manifestation in six ewe of each group. Estrus events were observed twice a day during the BS of 35 days, and estrus wer
ABSTRACT
Background: Complete isolation of genders allows intense estrous induction and synchronization once rams are introduced in ewe flocks at the onset of the breeding season (BS). This management practice, defined as the male effect, results from a neuroendocrine process mediated by pheromones. The male effect is a straightforward procedure to induce estrous in noncycling ewes, but conditions for its use have not been fully explored. Thus, this study aimed to evaluate hormone levels and ovarian activity of postpartum ewes in anestrus which are subjected to the male effect under different male to female ratios.Material, Methods & Results: Pospartum females were selected according to body condition score and cyclicity status. Females were kept apart from males during 30 days at a distance of 10 m. Anestrus and ovulation were determined by P4 measures on days 10, 20 and 30 after isolation from males. After P4 concentration diagnosis, anestrus ewe (n = 99) were subjected to male to ewe ratios (MFR) of 1:20 (MFR20), 1:30 (MFR30) and 1:40 (MFR40). Santa Inês rams (n = 3) of proven fertility were used. Three females of each group were randomly subjected to blood collection for LH concentration analysis. Ovarian activity was performed by ultrasonography after estrus manifestation in six ewe of each group. Estrus events were observed twice a day during the BS of 35 days, and estrus wer
ABSTRACT
Background: Complete isolation of genders allows intense estrous induction and synchronization once rams are introduced in ewe flocks at the onset of the breeding season (BS). This management practice, defined as the male effect, results from a neuroendocrine process mediated by pheromones. The male effect is a straightforward procedure to induce estrous in noncycling ewes, but conditions for its use have not been fully explored. Thus, this study aimed to evaluate hormone levels and ovarian activity of postpartum ewes in anestrus which are subjected to the male effect under different male to female ratios. Material, Methods & Results: Pospartum females were selected according to body condition score and cyclicity status. Females were kept apart from males during 30 days at a distance of 10 m. Anestrus and ovulation were determined by P4 measures on days 10, 20 and 30 after isolation from males. After P4 concentration diagnosis, anestrus ewe (n = 99) were subjected to male to ewe ratios (MFR) of 1:20 (MFR20), 1:30 (MFR30) and 1:40 (MFR40). Santa Inês rams (n = 3) of proven fertility were used. Three females of each group were randomly subjected to blood collection for LH concentration analysis. Ovarian activity was performed by ultrasonography after estrus manifestation in six ewe of each group. Estrus events were observed twice a day during the BS of 35 days, and estrus [...](AU)
Subject(s)
Animals , Male , Female , Reproductive Physiological Phenomena , Sheep/physiology , Anestrus , Estrus Synchronization/methods , Postpartum Period , Luteinizing Hormone , ProgesteroneABSTRACT
Background: Complete isolation of genders allows intense estrous induction and synchronization once rams are introduced in ewe flocks at the onset of the breeding season (BS). This management practice, defined as the male effect, results from a neuroendocrine process mediated by pheromones. The male effect is a straightforward procedure to induce estrous in noncycling ewes, but conditions for its use have not been fully explored. Thus, this study aimed to evaluate hormone levels and ovarian activity of postpartum ewes in anestrus which are subjected to the male effect under different male to female ratios. Material, Methods & Results: Pospartum females were selected according to body condition score and cyclicity status. Females were kept apart from males during 30 days at a distance of 10 m. Anestrus and ovulation were determined by P4 measures on days 10, 20 and 30 after isolation from males. After P4 concentration diagnosis, anestrus ewe (n = 99) were subjected to male to ewe ratios (MFR) of 1:20 (MFR20), 1:30 (MFR30) and 1:40 (MFR40). Santa Inês rams (n = 3) of proven fertility were used. Three females of each group were randomly subjected to blood collection for LH concentration analysis. Ovarian activity was performed by ultrasonography after estrus manifestation in six ewe of each group. Estrus events were observed twice a day during the BS of 35 days, and estrus [...]
Subject(s)
Male , Female , Animals , Anestrus , Reproductive Physiological Phenomena , Sheep/physiology , Estrus Synchronization/methods , Luteinizing Hormone , Postpartum Period , ProgesteroneABSTRACT
Background: Complete isolation of genders allows intense estrous induction and synchronization once rams are introduced in ewe flocks at the onset of the breeding season (BS). This management practice, defined as the male effect, results from a neuroendocrine process mediated by pheromones. The male effect is a straightforward procedure to induce estrous in noncycling ewes, but conditions for its use have not been fully explored. Thus, this study aimed to evaluate hormone levels and ovarian activity of postpartum ewes in anestrus which are subjected to the male effect under different male to female ratios.Material, Methods & Results: Pospartum females were selected according to body condition score and cyclicity status. Females were kept apart from males during 30 days at a distance of 10 m. Anestrus and ovulation were determined by P4 measures on days 10, 20 and 30 after isolation from males. After P4 concentration diagnosis, anestrus ewe (n = 99) were subjected to male to ewe ratios (MFR) of 1:20 (MFR20), 1:30 (MFR30) and 1:40 (MFR40). Santa Inês rams (n = 3) of proven fertility were used. Three females of each group were randomly subjected to blood collection for LH concentration analysis. Ovarian activity was performed by ultrasonography after estrus manifestation in six ewe of each group. Estrus events were observed twice a day during the BS of 35 days, and estrus wer
ABSTRACT
The objective of the present study was to determine if separation distance between bucks and does during two distinct climate seasons could affect the reproductive performance of goats subjected to a 45-day mating season (MS). Anglo Nubian does (n = 120) were kept apart from bucks at distances of 2 m (T1), 300 m (T2), and 2000 m (T3) for 60 days prior to the 45-day MS during two distinct climate seasons [dry season (DS, February to March) and rainy season (RS, September to October)] in Sertânia, Pernambuco state, Brazil. There were no effects of distance of separation between bucks and does in any response variable evaluated. However, during the DS, the mean of the first estrous manifestation varied significantly (P>0.05) between groups [7.13±4.49 (T1), 8.84±5.64 (T2), and 6.37±4.21 (T3) days] and during the RS [7.33±5.74 (T1), 6.60±4.88 (T2) and 8.10±4.87 (T3) days]. Similar (P>0.05) estrous induction rates were found during both the DS [100.00% (T1), 100.00% (T2) and 95.50% (T3)] and the RS [100.00% (T1), 100.00% (T2) and 100.00% (T3)]. The estrous synchronization rate was found to be lower during the DS [36.60%; 30.00% (T1), 35.00% (T2) and 45.00% (T3)] than during the RS [56.60%; 50.00% (T1), 60.00% (T2) and 60.00% (T3)]. Pregnancy rates during the DS [P>0.05; 80.00% (T1), 70.00% (T2) and 75.00% (T3)] were lower than during the RS [P>0.05; 90.00% (T1), 90.00% (T2) and 95.00%(T3)]. In summary, the separation distance between bucks and does did not affect the reproductive outcome of Anglo Nubian goats over a 45-day MS under tropical conditions. Greater reproductive outcome was observed during the RS than the DS regardless of the separation distance between bucks and does...(AU)
O objetivo do presente estudo foi determinar se a distância de isolamento entre machos e fêmeas avaliado durante dois períodos climáticos distintos afeta o desempenho reprodutivo de caprinos submetidos a uma estação de monta (EM) de 45 dias. Fêmeas Anglo Nubianas (n = 120) foram afastadas dos machos por distâncias de 2 m (T1), 300 m (T2) e 2000 m (T3) por 60 dias antes da EM de 45 dias sob diferentes condições climáticas [estação seca (ES, Fevereiro a Março) e estação chuvosa (EC, Setembro a Outubro)] em Sertânia, estado de Pernambuco, Brasil. Não houve efeito da distância de pré-condicionamento entre machos e fêmeas em nenhuma variável avaliada. No entanto, durante a ES, a média da primeira manifestação de estro variou (P>0,05) entre os grupos [7,13±4,49 (T1), 8,84±5,64 (T2) e 6,37±4,21 (T3) dias] e durante a EC [7,33±5,74 (T1), 6,60±4,88 (T2) e 8,10±4,87 (T3)]. A taxa de indução de estro foi semelhante (P>0,05) entre ES [100,00% (T1), 100,00% (T2) e 95,50% (T3)] e EC [100,00% (T1), 100,00% (T2) e 100,00% (T3)]. A sincronização do estro foi inferior durante a ES [36,60%, 30,00% (T1), 35,00% (T2) e 45,00% (T3)] que durante a EC [56,60%, 50,00% (T1), 60,00% (T2) e 60,00% (T3)]. As taxas de prenhez na ES [P>0,05; 80,00% (T1), 70,00% (T2) e 75,00% (T3)] foram menores do que em EC [P>0,05; 90,00% (T1), 90,00% (T2) e 95,00% (T3)]. Em conclusão, a distância de pré-condicionamento entre machos e fêmeas não afetou o desempenho reprodutivo durante a EM de 45 dias de caprinos Anglo Nubianos sob condições tropicais. Um desempenho reprodutivo maior foi observado durante a estação chuvosa comparado a estação seca, independente da distância de pré-condicionamento...(AU)
Subject(s)
Animals , Sexual Behavior, Animal , Climate Change/statistics & numerical data , Sheep/classificationABSTRACT
The objective of the present study was to determine if separation distance between bucks and does during two distinct climate seasons could affect the reproductive performance of goats subjected to a 45-day mating season (MS). Anglo Nubian does (n = 120) were kept apart from bucks at distances of 2 m (T1), 300 m (T2), and 2000 m (T3) for 60 days prior to the 45-day MS during two distinct climate seasons [dry season (DS, February to March) and rainy season (RS, September to October)] in Sertânia, Pernambuco state, Brazil. There were no effects of distance of separation between bucks and does in any response variable evaluated. However, during the DS, the mean of the first estrous manifestation varied significantly (P>0.05) between groups [7.13±4.49 (T1), 8.84±5.64 (T2), and 6.37±4.21 (T3) days] and during the RS [7.33±5.74 (T1), 6.60±4.88 (T2) and 8.10±4.87 (T3) days]. Similar (P>0.05) estrous induction rates were found during both the DS [100.00% (T1), 100.00% (T2) and 95.50% (T3)] and the RS [100.00% (T1), 100.00% (T2) and 100.00% (T3)]. The estrous synchronization rate was found to be lower during the DS [36.60%; 30.00% (T1), 35.00% (T2) and 45.00% (T3)] than during the RS [56.60%; 50.00% (T1), 60.00% (T2) and 60.00% (T3)]. Pregnancy rates during the DS [P>0.05; 80.00% (T1), 70.00% (T2) and 75.00% (T3)] were lower than during the RS [P>0.05; 90.00% (T1), 90.00% (T2) and 95.00%(T3)]. In summary, the separation distance between bucks and does did not affect the reproductive outcome of Anglo Nubian goats over a 45-day MS under tropical conditions. Greater reproductive outcome was observed during the RS than the DS regardless of the separation distance between bucks and does...
O objetivo do presente estudo foi determinar se a distância de isolamento entre machos e fêmeas avaliado durante dois períodos climáticos distintos afeta o desempenho reprodutivo de caprinos submetidos a uma estação de monta (EM) de 45 dias. Fêmeas Anglo Nubianas (n = 120) foram afastadas dos machos por distâncias de 2 m (T1), 300 m (T2) e 2000 m (T3) por 60 dias antes da EM de 45 dias sob diferentes condições climáticas [estação seca (ES, Fevereiro a Março) e estação chuvosa (EC, Setembro a Outubro)] em Sertânia, estado de Pernambuco, Brasil. Não houve efeito da distância de pré-condicionamento entre machos e fêmeas em nenhuma variável avaliada. No entanto, durante a ES, a média da primeira manifestação de estro variou (P>0,05) entre os grupos [7,13±4,49 (T1), 8,84±5,64 (T2) e 6,37±4,21 (T3) dias] e durante a EC [7,33±5,74 (T1), 6,60±4,88 (T2) e 8,10±4,87 (T3)]. A taxa de indução de estro foi semelhante (P>0,05) entre ES [100,00% (T1), 100,00% (T2) e 95,50% (T3)] e EC [100,00% (T1), 100,00% (T2) e 100,00% (T3)]. A sincronização do estro foi inferior durante a ES [36,60%, 30,00% (T1), 35,00% (T2) e 45,00% (T3)] que durante a EC [56,60%, 50,00% (T1), 60,00% (T2) e 60,00% (T3)]. As taxas de prenhez na ES [P>0,05; 80,00% (T1), 70,00% (T2) e 75,00% (T3)] foram menores do que em EC [P>0,05; 90,00% (T1), 90,00% (T2) e 95,00% (T3)]. Em conclusão, a distância de pré-condicionamento entre machos e fêmeas não afetou o desempenho reprodutivo durante a EM de 45 dias de caprinos Anglo Nubianos sob condições tropicais. Um desempenho reprodutivo maior foi observado durante a estação chuvosa comparado a estação seca, independente da distância de pré-condicionamento...