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Advisor(s)
Abstract(s)
Do ponto de vista da Produção Ovina é importante conhecer a eficácia da aplicação das
técnicas de controlo reprodutivo e de inseminação artificial (IA) em explorações comerciais.
O presente trabalho teve como principal objectivo avaliar a eficácia da aplicação de um
tratamento prévio com melatonina e de dois tratamentos progestagénicos curtos (FGA vs.
MAP) + eCG (750 UI) no controlo da actividade reprodutiva de ovelhas cruzadas
Awassi x Sarda, durante o mês de Maio. Simultaneamente procurou-se avaliar os efeitos da
utilização de dois diluidores seminais – Andromed® vs. OviXcell® – e do método de
preservação do sémen – Fresco vs. Refrigerado – na IA destes animais.
O ensaio foi realizado em Carviçais, Torre de Moncorvo, mais precisamente na
Exploração Comercial (Mateus Lda.), entre os meses de Abril e de Julho de 2017. Nele foram
utilizadas 110 ovelhas lactantes cruzadas de Awassi x Sarda e dois carneiros Assaf. Inicialmente
as ovelhas foram divididas em dois grupos: Controlo (n = 47) e Melatonina (n = 63). As ovelhas
do grupo Controlo não receberam qualquer tratamento. As ovelhas do grupo Melatonina
receberam um implante subcutâneo (18 mg) de melatonina/fêmea. Sessenta dias depois, 83
ovelhas foram tratadas com esponjas vaginais de 20 mg de FGA e 27 ovelhas com esponjas
vaginais de 60 mg de MAP. Nessa altura, todas as ovelhas foram injectadas via subcutânea com
100 g de Prostaglandina F2 (PGF2α). Os tratamentos progestagénicos duraram 7 dias. Quando
da remoção das esponjas vaginais, todas as ovelhas receberam uma injecção de 750 UI de eCG.
A IA foi realizada 55 + 1 horas depois da remoção das esponjas. Cinquenta e seis ovelhas foram
inseminadas com sémen fresco: 29 com doses seminais diluídas com Andromed® e 27 com
OviXcell®. As demais 54 ovelhas foram inseminadas com sémen refrigerado: 29 das doses
seminais foram diluídas com Andromed® e 25 com OviXcell®. Avaliou-se a ciclicidade pré e
pós-tratamentos progestagénicos curtos + eCG e a percentagem de ovelhas gestantes 38 dias
pós-inseminação.
Na segunda quinzena de Maio, todas as ovelhas Awassi x Sarda estavam cíclicas. Ambos
os tratamentos progestagénios curtos (FGA ou MAP) + eCG foram eficazes. A administração
prévia de melatonina não afectou a percentagem de ovelhas que ovularam em resposta aos
tratamentos progestagénicos + eCG. O FGA e o MAP foram igualmente eficazes na
sincronização do momento de formação do primeiro CL. Trinta e oito dias após a IA, 74,5%
das ovelhas Awassi x Sarda estavam gestantes. A taxa de fertilidade foi significativamente
influenciada pela idade das ovelhas, pelo carneiro dador de sémen, pelo tipo de Os externo,
pelo local de deposição do sémen e pelo refluxo cervical. A taxa de fertilidade não foi significativamente alterada pelo número de partos (Primíparas vs. Multíparas), método de
preservação do sémen (Fresco vs. Refrigerado), pelo tipo de diluidor (Andromed® vs.
OviXcell®).
The knowledge of the efficiency of reproduction control techniques and artificial insemination (AI) is very important in commercial farms. This work aimed to assess the effectiveness of a prior melatonin and two short progestogen treatments (FGA vs. MAP) + eCG (750 UI) in the control of the ovarian activity of cross-bred Awassi x Sarda sheep at May. Simultaneously, the effects of two seminal extenders – Andromed® vs. OviXcell® – and two method of semen preservation – Fresh vs. Cooled –in the AI of these ewes were evaluated. This experiment took place in Carviçais, Torre de Moncorvo, at a commercial farm (Mateus Ltd) between April and July of 2017. One-hundred and ten lactating Awassi x Sarda ewes and two Assaf rams were used. Primarily ewes were divided into two groups: Control (n = 47) and Melatonin (n = 63). Control ewes received no treatment. Melatonin ewes were treated with a subcutaneous melatonin implant (18 mg). Sixty days later, 83 ewes were treated with a vaginal sponge of FGA (20 mg) and 27 with a vaginal sponge of MAP (60 mg). Simultaneously all ewes received a subcutaneous injection with 100 μg of Prostaglandin F2α (PGF2α). Progestogen treatments lasted for 7 days. At sponges removal all ewes received an injection of 750 UI of eCG. AI was performed 55 + 1 hours after sponge removal. Fifty six ewes were inseminated with fresh semen: 29 with semen extended with Andromed® and the other 27 with semen extended with OviXcell®. The remaining 54 ewes were inseminated with cooled semen: 29 with semen extended with Andromed® and the other 25 with semen extended with OviXcell®. Pre and post short-term progestogen + eCG treatments ovarian activity was assessed as well as the fertility rate (38 days after AI). All Awassi x Sarda ewes ovulated at the second fortnight of May. Both short-term progestogen treatments (FGA or MAP) + eCG were quite efficient. Previous administration of melatonin did not affect the percentage of ewes responding to the progestogen + eCG treatments. FGA and MAP were equally efficient. About 74.5% of the Awassi x Sarda ewes were pregnant 38 days after AI. Fertility rate was significantly influenced by age, semen donor, type of external Os, place of semen deposition and cervical reflux. On the contrary fertility rate was not significantly affected by parity (Primiparous vs. Multiparous), semen preservation method (Fresh vs. Cooled) or seminal extender (Andromed® vs. OviXcell®).
The knowledge of the efficiency of reproduction control techniques and artificial insemination (AI) is very important in commercial farms. This work aimed to assess the effectiveness of a prior melatonin and two short progestogen treatments (FGA vs. MAP) + eCG (750 UI) in the control of the ovarian activity of cross-bred Awassi x Sarda sheep at May. Simultaneously, the effects of two seminal extenders – Andromed® vs. OviXcell® – and two method of semen preservation – Fresh vs. Cooled –in the AI of these ewes were evaluated. This experiment took place in Carviçais, Torre de Moncorvo, at a commercial farm (Mateus Ltd) between April and July of 2017. One-hundred and ten lactating Awassi x Sarda ewes and two Assaf rams were used. Primarily ewes were divided into two groups: Control (n = 47) and Melatonin (n = 63). Control ewes received no treatment. Melatonin ewes were treated with a subcutaneous melatonin implant (18 mg). Sixty days later, 83 ewes were treated with a vaginal sponge of FGA (20 mg) and 27 with a vaginal sponge of MAP (60 mg). Simultaneously all ewes received a subcutaneous injection with 100 μg of Prostaglandin F2α (PGF2α). Progestogen treatments lasted for 7 days. At sponges removal all ewes received an injection of 750 UI of eCG. AI was performed 55 + 1 hours after sponge removal. Fifty six ewes were inseminated with fresh semen: 29 with semen extended with Andromed® and the other 27 with semen extended with OviXcell®. The remaining 54 ewes were inseminated with cooled semen: 29 with semen extended with Andromed® and the other 25 with semen extended with OviXcell®. Pre and post short-term progestogen + eCG treatments ovarian activity was assessed as well as the fertility rate (38 days after AI). All Awassi x Sarda ewes ovulated at the second fortnight of May. Both short-term progestogen treatments (FGA or MAP) + eCG were quite efficient. Previous administration of melatonin did not affect the percentage of ewes responding to the progestogen + eCG treatments. FGA and MAP were equally efficient. About 74.5% of the Awassi x Sarda ewes were pregnant 38 days after AI. Fertility rate was significantly influenced by age, semen donor, type of external Os, place of semen deposition and cervical reflux. On the contrary fertility rate was not significantly affected by parity (Primiparous vs. Multiparous), semen preservation method (Fresh vs. Cooled) or seminal extender (Andromed® vs. OviXcell®).
Description
Mestrado com dupla diplomação com a Universidade Tecnológica Federal do Paraná
Keywords
Ovinos Awassi x Sarda Melatonina FGA MAP Super-ovulação IA