Effect of different protocols for estrus synchronization on reproductive performance of Santa Inês ewes under Amazon environmental conditions

Abstract

The objective of this study was to evaluate the effect of different hormonal protocols on the reproductive performance of Santa Inês ewes in Amazon environmental conditions. Twenty-two Santa Inês ewes between 3 and 4 years-old were distributed in a randomized block experimental design, where the treatments consisted of two protocols for estrus synchronization (short and long) with eleven animals each. Data on the occurrence of estrus were described for each protocol. Data of estrus, pregnancy, and prolificity were firstly subjected to ANOVA and a subsequent Tukey’s test. Results were considered significant at p ≤ 0.05. The short-term protocol presented an interesting successful rate, where above 70% ewes tested had estrus. The long-term protocol also achieved a high successful rate, where above 80% ewes tested had estrus. However, comparing the protocols, the long-term protocol presented better results of positive estrus and pregnancy rates in ewes. Thus, it can be concluded that both protocols presented satisfactory results regarding estrus manifestation, and prolificity (lambs produced per ewe). However, under Amazon environmental conditions, the long-term protocol presented better results regarding positive manifestation of estrus and pregnancy rate.

Age as a Determinant of the Effectiveness of Intravaginal Sponges Impregnated with Progestin and Equine Chorionic Gonadotropin for Multiple Births Induction of Awassi Ewes

“…Te current results confrmed the efciency of the present protocol in improving and expanding the sheep population because the ratio of twins is only 5% among Awassi ewes [24], while some researchers also suggested the efcacy of long-term progesterone protocol in both estrus synchronization and pregnancy rates [8,12,25], while other recorded a low rate of pregnancy (40%) only when a similar protocol of synchronization on Pirlak ewes was used out of the breeding season [3]. Te present multiple births were higher than that recorded by other researchers [1,2] who recorded a pregnancy rate of 86.7% and 75.6% in Akkaraman and Kivircik ewes, respectively, and 95-212% in Iraq Awassi ewes in 12 provinces [6].…”

Comparative study of short term and long term protocols for progesterone based estrus synchronization in ewes during breeding season

“…Progestagen analogues are widely used in small ruminants to induce and synchronize estrous (Emsen and Yaprak 2006). Recent studies (Marteniz-Ros et al 2018, Silva et al 2021) have focused on the duration of the progestagen-based synchrony treatments. In the current study, estrus was expressed following intravaginal progesterone sponge removal in 73.3% ewes, indicating its usefulness in inducing ovarian activity and estrus expression during breeding season.…”

“…Progestagen analogues are widely used for this purpose (Emsen and Yaprak 2006). Most of the recent studies have focussed on the duration of the progestagen-based synchrony treatments (Marteniz-Ros et al 2018, Silva et al 2021. In these protocols, the intra-vaginal devices containing different types of progestagens are retained for 6 to 14 days.…”

Technologies Used in Production Systems for Santa Inês Sheep: A Systematic Review

“…Also aiming to reduce costs, Prates et al ( 45 ) evaluated human intravaginal tampons soaked with human progesterone for induction and synchronization of estrus in Santa Inês ewes, verifying that these can be used alternatively for this purpose. Comparing the effect of short and long protocols based on progesterone and equine chorionic gonadotropin (eCG), Silva et al ( 46 ) found that under the Amazon environment, the second one showed better results.…”