Different estrous induction methods during the non-breeding season in Kivircik ewes

Abstract

ABSTRACT:The efficiency of medroxyprogesterone acetate (MAP) sponges in combination with either pregnant mare serum gonadotrophin (PMSG) or cloprostenol (PGF 2α ) for inducing and synchronizing the estrous cycle in non-lactating Kivircik ewes was investigated during the natural non-breeding season. All ewes (n = 69) were treated with 60 mg MAP sponges for 12 days. In addition, each ewe received an intramuscular injection of either 1.5 ml sterile saline solution (n = 18); 125 µg PGF 2α (n = 14); 500 IU PMSG (n = 18) or 500 IU PMSG and 125 µg PGF 2α (n = 19), 48 h before the sponge removal. Cervical artificial insemination (AI) with diluted fresh semen was performed at a fixed time (48 and 60 h) following progestagen withdrawal. The different groups estrous response for the first 24 ± 6 h and within 120 h, time to onset and duration of the induced estrous, and pregnancy rate was found to be 36.2%, 81.6%, 41.7 ± 2.3 h, 29.6 ± 1.5 h, and 54.5%, respectively. There were significant differences between groups MAP and MAP/PGF 2α and their with the two latter groups (MAP/PMSG, MAP/PMSG/PGF 2α ) in terms of the onset of induced estrous (P < 0.05) and between groups MAP and MAP/PGF 2α in terms of the duration of induced estrous (P < 0.05) and between the first two groups (MAP, MAP/PGF 2α ) and the latter two groups (MAP/PMSG, MAP/PMSG/PGF 2α ) in terms of estrous response at the first 24 ± 6 h (P < 0.05). These results indicate that, the use of MAP/PMSG, rather than MAP or MAP/PGF 2α , was effective in the attainment of early and compact induction and synchronization of estrous in non-lactating Kivircik ewes during the natural non-breeding season.

Studies on Estrus Induction in Ewes during Non-Breeding Season

“…Likewise, our results in PMSG treated ewes (Group I, Group III) are in close agreement with results of Boland et al, (1979), Carpenter et al, (1981), Alifakiotis (1985), Tritschler et al, (1991), Amer and Hazzaa (2009), Kor et al, (2012). Differing from our results, lower estrus induction rates ranging from 46% to 93% were reported by Redmer et al, (1998), Kusina et al, (2000), Mellado et al, (2000), Das et al, (2004), Ataman et al, (2006), Dogan and Nur (2006), Ali (2007), Abu Gazal (2010), Bogdan et al, (2011), Santos et al, (2011), Sarminejad et al, (2014.…”

“…Our results are in complete agreement with earlier results of Botha et al, (1975), Dogan and Nur (2006), Omontese et al, (2012), Cline et al, (2001), Redmer et al, (1998) and Gardon et al, (2015) who reported that time to estrus was shorter in eCG treated ewes than eCG untreated ewes.…”

The Effect of Injectable Vitamin E and Trace Minerals (Selenium, Calcium, Phosphate, Copper, and Cobalt) on Reproductive Performance During Non-Breeding Season in Awassi Ewes

“…The overall average interval elapsed from sponge removal to onset of estrus was 44.2±0.7 in this study (see Table). The interval obtained in this trial was comparable to the findings of M. Ali [12] and I. Dogan et al [13], and was longer than the 38.8±1.6 h reported by R. Ungerfeld et al [14], but shorten than the 69.0±9.9 h reported by А. Ali [15]. It may be affected many exogenous factors such as nutrition, daylight, environmental factors, presence of male after sponge removal.…”

Medroxiprogesterona acetato para la elaboración de dispositivos intravaginales caseros usados en la sincronización del estro en ovinos de pelo: Evaluación de su eficacia, sus efectos secundarios y comparación con un dispositivo comercial en hatos de Costa Rica.

“…De tal manera que, la eficacia del progestágeno puede ser determinada como la ausencia de estro durante el tratamiento y su aparición sincrónica después de retirarlo. Sin embargo, la administración de eCG, la cual presenta un importante efecto FSH (Abecia et al 2012), en dosis racionales aumenta la tasa de ovulación al inducir el reclutamiento folicular (Fernández-Abella et al 2003;Barret et al 2004) y disminuye el intervalo entre la remoción de MAP y la aparición del estro, comparado con el uso de progestágenos solamente (Barret et al 2004;Dogan & Nur 2006). La administración de una dosis luteolítica de PGF 2α al final o 24-48 horas antes de retirar el dispositivo intravaginal ha resultado en un aumento de la tasa de fertilidad (Martemucci & D´Alessandro 2011).…”

“…La técnica de sincronización más aceptada, a nivel mundial, en esta especie, incluye el uso de esponjas impregnadas con progestágenos para uso intravaginal, con o sin la adición de otras hormonas, tales como prostaglandinas y sus análogos y gonadotropina coriónica equina (eCG) (Robinson et al 1968;Fukui et al 1987;Fukui et al 1999;Simonetti et al 2000;Zarwaki et al 2001;Espinoza et al 2003;Ungerfeld et al 2003;Barret et al 2004;Wulster-Radcliffe et al 2004;Catalano et al 2005;Dogan & Nur 2006;Catalano et al 2007;Martínez-Tinajero et al 2007;Hernández-Olivos 2010;. Según los autores citados, el progestágeno más utilizado es la medroxiprogesterona acetato (MAP).…”