Manejo del periodo postparto para incrementar la actividad reproductiva de la oveja pelibuey.

Abstract

Con la finalidad de evaluar el manejo del periodo postparto para incrementar la actividad reproductiva de la oveja Pelibuey se realizaron tres experimentos (EXP). En el EXP1 se evaluó la prolificidad y fecundidad en el restablecimiento de la actividad ovárica postparto en ovejas Pelibuey. Se utilizaron 69 ovejas Pelibuey, que se distribuyeron en tres tratamientos: Tratamiento 1 (T1), hembras vacías (n = 16); Tratamiento 2 (T2), hembras destetadas (n = 24); Tratamiento 3 (T3), hembras amamantando (n = 45), crías con madres durante todo el experimento. En el EXP2, se determinó que el amamantamiento controlado y el “efecto macho” desde el día siete postparto incrementan el número de ovejas que reinician su actividad ovárica antes del destete (60 d postparto) y reduce el intervalo parto-primera ovulación, así como el cambio de peso corporal en las ovejas y de los corderos durante el periodo postparto. Se utilizaron 152 ovejas Pelibuey, asignadas al azar a uno de cuatro tratamientos. amamantamiento continuo (AC; n = 38), amamantamiento controlado (Ac; n = 38), AC + “efecto macho” (ACEM; n = 38) y Ac + “efecto macho” (AcEM; n = 38). El reinicio de la actividad ovárica postparto (días) y la ganancia diaria de peso de las ovejas y corderos se determinaron y el porcentaje de ovejas que ovularon se calculó. En el EXP3, se evaluó la prolificidad y fecundidad en el restablecimiento de la actividad ovárica postparto en ovejas Pelibuey en el postparto. Se utilizaron 37 ovejas Pelibuey, que se distribuyeron en dos tratamientos: Tratamiento 1 (T1), amamantamiento continuo (n = 16; con más de 30 días postparto); y Tratamiento 2 (T2), (n = 21; menos de 30 días postparto), crías con madres durante todo el experimento. En el EXP1, se observó que no hay diferencias (α = 0.05) entre tratamientos en ovejas que entraron en estro. En inicio al estro, de manera similar no se observaron diferencias (α = 0.05), aunque se observó que T1 tardo más días en el restablecimiento de la actividad ovárica; tampoco se observó en los animales que retornaron al estro diferencia (α = 0.05). No se encontraron diferencias (α = 0.05) en fertilidad, prolificidad y fecundidad, donde las hembras de T1 y T3 tuvieron la prolificidad mayor (1.5a) y T3 la fecundidad mayor (1.2a) que los animales de T2 (0.9a) y T1 (1.0a). Por lo que se concluye que, el manejo reproductivo de las hembras amamantando, para que restablezcan la actividad ovárica durante el postparto, no es diferente al manejo reproductivo de las hembras no gestantes y el de las destetadas. En el EXP2, se observó que en el tiempo de reinicio de actividad ovárica postparto (primer incremento en los niveles de progesterona (P4)) hubo diferencias (p < 0.05). AC y Ac no fueron diferentes (p > 0.05; 53.61 ± 4.36 y 50.11 ± 3.7); en contraste, en las ovejas del tratamiento AcEM se observó que la concentración de P4 se presentó más rápido (p < 0.05; 27.72 ± 0.56 d) que en los otros tratamientos. También, AC (55.3 %) fue diferente a Ac (89.5 %), ACEM (92.1 %) y AcEM (97.4 %). Las ovejas de AC ganaron más peso (p < 0.05; 9.77 ± 0.93 kg) que Ac (5.92 ± 0.65 kg), ACEM (4.21 ± 0.6 kg) y AcEM (6.93 ± 0.71 kg) y los corderos de los tratamientos AC (11.37 ± 0.4 kg) y ACEM (11.55 ± 0.5 kg) ganaron más peso (p < 0.05) que Ac (8.42 ± 0.51 kg). El control del amamantamiento y el efecto macho estimulan el restablecimiento de la actividad ovárica postparto y provocan la ovulación en ovejas Pelibuey. En el EXP3, se observó utilizando un α = 0.05 entre tratamientos la respuesta al estro en ovejas Pelibuey en la cual no hubo diferencia. Tampoco existieron diferencias (α = 0.05) entre T1 y T2 al entrar en estro. Aunque se observó que T1 retrasó más el restablecimiento de la actividad ovárica; no se visualiza en los animales de retorno al estro diferencia (α = 0.05). En inicio al estro no se observaron diferencias (α = 0.05). Se observó que no se encontraron diferencias (α = 0.05) en fertilidad, prolificidad de los animales con más de 30 días con sus crías y en fecundidad, los animales T1 tuvieron la fecundidad mayor (1.2a) que los animales de T2 (0.96a). Por lo anterior se concluye que en animales con amamantamiento continuo con >30 y <30 días postparto, el manejo para el restablecimiento de la actividad ovárica postparto se ve reflejado en la prolificidad y fecundidad sin ser significativos (α = 0.05). _______________ MANAGEMENT OF THE POSTPARTUM PERIOD TO INCREASE THE REPRODUCTIVE ACTIVITY OF THE PELIBUEY SHEEP. ABSTRACT: In order to evaluate the management of the postpartum period to increase the reproductive activity of Pelibuey sheep, three experiments (EXP) were performed. In the EXP1, prolificity and fecundity were evaluated in the restoration of postpartum ovarian activity in Pelibuey sheep. 69 Pelibuey sheep were used, which were distributed in three treatments: Treatment 1 (T1), empty females (n = 16); Treatment 2 (T2), weaned females (n = 24); Treatment 3 (T3), breastfeeding females (n = 45), offspring with mothers throughout the experiment. In EXP2, it was determined that controlled breastfeeding and the "male effect" from day seven postpartum increased the number of ewes that restarted their ovarian activity before weaning (60 d postpartum) and reduced the delivery-first ovulation interval, as well as The change in body weight in sheep and lambs during the postpartum period. A total of 152 Pelibuey sheep were randomly assigned to one of four treatments. (Ac; n = 38), AC + "male effect" (ACEM; n = 38) and Ac + "male effect" (AcEM; n = 38). The resumption of postpartum ovarian activity (days) and the daily weight gain of sheep and lambs were determined and the percentage of sheep that ovulated was calculated. In EXP3, prolificity and fecundity were evaluated in the restoration of postpartum ovarian activity in Pelibuey sheep at postpartum. Thirty-seven Pelibuey sheep were used, which were distributed in two treatments: Treatment 1 (T1), continuous suckling (n = 16, more than 30 days postpartum); And Treatment 2 (T2), (n = 21, less than 30 days postpartum), offspring with mothers throughout the experiment. In EXP1, it was observed that there were no differences (α = 0.05) between treatments in ewes that went into estrus. At the start of estrus, similar differences were not observed (α = 0.05), although it was observed that T1 delayed more days in the reestablishment of ovarian activity; Neither was observed in the animals that returned to estrus difference (α = 0.05). There were no differences (α = 0.05) in fertility, prolificacy and fecundity, where females of T1 and T3 had higher prolificacy (1.5a) and T3 had higher fertility (1.2a) than T2 animals (0.9a) and T1 (1.0a). Therefore, it is concluded that reproductive management of breastfeeding females, in order to restore ovarian activity during postpartum period, is not different from the reproductive management of non-pregnant females and weaning females. In EXP2, it was observed that there was a difference (p <0.05) in the time of resumption of postpartum ovarian activity (first increase in progesterone levels (P4)). AC and Ac were not different (p> 0.05, 53.61 ± 4.36 and 50.11 ± 3.7); In contrast, sheep in the AcEM treatment showed that the P4 concentration was faster (p <0.05, 27.72 ± 0.56 d) than in the other treatments. Also, AC (55.3%) was different from Ac (89.5%), ACEM (92.1%) and AcEM (97.4%). ACEM (4.21 ± 0.6 kg) and ACEM (6.93 ± 0.71 kg) and lambs from the AC treatments (11.37 kg / ha) showed a greater weight gain (p <0.05, 9.77 ± 0.93 kg) than Ac (5.92 ± 0.65 kg) ± 0.4 kg) and ACEM (11.55 ± 0.5 kg) gained more weight (p <0.05) than Ac (8.42 ± 0.51 kg). Control of breastfeeding and the male effect stimulate the reestablishment of postpartum ovarian activity and cause ovulation in Pelibuey sheep. In the EXP3, it was observed using an α = 0.05 between treatments the response to estrus in Pelibuey sheep in which there was no difference. There were also no differences (α = 0.05) between T1 and T2 when entering estrus. Although it was observed that T1 delayed the reestablishment of ovarian activity more; It is not visualized in the animals returning to estrus difference (α = 0.05). At the start of estrus, no differences were observed (α = 0.05). It was observed that there were no differences (α = 0.05) in fertility, prolificacy of the animals with more than 30 days with their offspring and in fecundity, T1 animals had higher fecundity (1.2a) than T2 animals (0.96a ). Therefore, in animals with continuous suckling with> 30 and <30 days postpartum, management for reestablishment of postpartum ovarian activity is reflected in prolificity and fecundity without being significant (α = 0.05).