RESUMO
The effect of goat nutritional condition on the response to biostimulation with sexually active males during different stages of anestrus was determined. Fifty-eight Criollo × Nubian females on high and low body mass index (BMI) diets were used. Each BMI group was divided into two for biostimulation with sexually active males during May (mid-anestrus) or July (transition period). Ovulatory responses to biostimulation were characterized from serum progesterone, as well as the delay for response (first and second ovulations followed by a normal length luteal phase, O-WNLP). The percentage of goats showing one O-WNLP was greater in the high BMI group than in the low BMI group and greater during the transition period than in the mid-anestrus. However, the interaction between factors revealed that the difference between BMI groups was only significant in the transition period and the difference between stages was only significant in goats with high BMI. Occurrence of a second O-WNLP tended to be greater in the high BMI group than in the low BMI group. Response delay was shorter in the transition period than in mid-anestrus. In conclusion, female nutritional status interacting with the stage of anestrus determined the ovulatory response to male biostimulation in crossbred Criollo goats.
Assuntos
Anestro/fisiologia , Anovulação/fisiopatologia , Anovulação/psicologia , Cabras/fisiologia , Estado Nutricional/fisiologia , Ovulação/fisiologia , Comportamento Sexual Animal/fisiologia , Animais , Feminino , Cabras/psicologia , Masculino , Estimulação Física , Estações do AnoRESUMO
The objective was to determine the effect of body energy stores, evaluated by a body mass index (BMI), and food intake (FI), on the length of the anovulatory period and ovarian activity during the seasonal reproductive transitions in Creole goats. Non-pregnant, non-lactating Creole goats (n=28) were fed to induce two different BMI conditions: Greater (GBMI; n=15), and Lesser (LBMI; n=13). Each BMI group was divided into two sub-groups, which were either feed restricted (FR) or non-feed restricted (NFR). Goats in the NFR groups received a diet containing 100% of the daily maintenance requirements (basal diet), while restricted goats were subjected to alternated periods, receiving 100% (11d) and 60% (10d) of the basal diet, during the entire experimental period. The experiment started after does were treated to synchronize time of estrus. Serum progesterone was determined in samples obtained twice a week, and used as a criterion for determining ovulations. During the transition to the anovulatory period three transrectal ovarian ultrasonographic scans were performed in a sub-group of 12 goats (n=3 for each treatment combination). The diameter of the largest follicle (LFD) and the total number of antral follicles >or=2mm (TAF) were recorded. Ultrasonographic ovarian scans were performed at 21, 42 and 63 days after the beginning of the experiment, concurrently with the end of each feed restriction period. The variables of response associated with ovulation were not influenced by BMI or BMIxFI interaction. However, FI influenced length of anovulatory season, as the anovulatory period was 30d longer (P<0.05) in the FR group as compared with the NFR group. Independently of treatments, TAF and LFD decreased from the first to the third ultrasonographic ovarian scan (13.2, 10.8 and 4.4 follicles; 3.7, 2.7 and 2.3mm). Nevertheless, in PER 1 the number of TAF was greater (P<0.05) in the FR as compared with NFR group and the GBMI group had a larger LFD (P<0.05) as compared to the LBMI group. It is concluded, that temporal restriction in feed intake could affect the time of cessation and initiation of ovulations during the periods of transition to seasonal anestrus and return to estrous activity, and increase the length of the anovulatory period. In addition, ovarian follicular development during transition into the anovulatory period is differentially influenced by food intake and the status of body energy stores.
Assuntos
Estado Nutricional/fisiologia , Ovário/fisiologia , Reprodução/fisiologia , Estações do Ano , Animais , Anovulação/fisiopatologia , Índice de Massa Corporal , Restrição Calórica/veterinária , Sincronização do Estro/métodos , Sincronização do Estro/fisiologia , Feminino , Folículo Ovariano/fisiologia , Ovário/diagnóstico por imagem , Fatores de Tempo , UltrassonografiaRESUMO
El objetivo del estudio fue evaluar si la dosis reducida de un análogo de la prostaglandina (Luprostiol) (LP) por vía submucosa intravulvar (SMIV) e ipsilateral al cuerpo lúteo (IPL) inducen la luteólisis y la manifestación del estro. Se utilizaron 39 vacas de la raza Suizo Pardo en producción con ciclos estrales regulares, las cuales fueron asignadas a los siguientes tratamientos: 15 mg de LP por vía intramuscular (n=13); T1, 11.2 mg de LP por vía SMIV e IPL (n=13); T2, 7.5 mg de LP por vía SMIV e IPL (n=13). Se tomaron muestras sanguíneas para medir la concentración plasmática de progesterona (P4) a la 0 h y posteriormente cada 12 h, hasta las 72 h postratamiento. Se consideró la luteólisis (LUT) cuando las concentraciones de P4 fueron menores de 1 ng/ml y se mantuvieron hasta las 72 h postratamiento. A las 0 h, inicio de los tratamientos, la concentración de P4 fue de 3.22 ng/ml, después de las 24 h los niveles de P4 fueron menores de 1 ng/ml y se mantuvieron hasta las 72 h postratamiento, sin mostrar diferencia entre los grupos tratados (P>0.05). El porcentaje total del estro (PTE) (84.1 por ciento) y el intervalo tratamiento-manifestación del estro (ITE) (86.4 h) fueron similares entre tratamientos (P>0.05). El peso corporal, el nivel de producción láctea, el número de parto y el intervalo parto-tratamiento no fueron determinantes para efectuar la LUT, el ITE y el PTE (P>0.05). Las vacas que recibieron dosis reducidas de LP por vía SMIV e IPL tuvieron LUT, ITE y PTE similares a los observados en vacas con una dosis completa y por vía intramuscular