Synchronization In Ewes Research Articles

Effect of Different Protocols of Estrus Synchronization on Vaginal Microflora with Antibiotic Susceptibility to Bacteria

To investigate the effect of different protocols for estrus synchronization in ewes on the vaginal tract bacteria and evaluate the sensitivity of bacteria to different antibiotics. Sixteen local breed ewes were allocated to four groups, each containing four. Group A: ewes treated with sponges for 10 days; Group B ewes treated with CIDR for 10 days; Group C ewes treated with sponges for 14 days and finally Group D ewes treated with CIDR for 14 days. Sterile swaps were taken from the vaginaʼs mucous before insertion of sponge or CIDR and after removing it for each group. Vaginal swabs from synchronized ewes were obtained from the vaginaʼs mucous before insertion of sponge or CIDR and after removing it for each group to use in different bacteriological tests. The results showed that the most dominant bacteria were E-Coli 7/7 (100%), and Staphylococcus aureus (71%) before insertion, while in group A, the percentage was 75% and 100% for E-Coli only in group B and group C respectively. According to E-coli, the results showed that it was more sensitive to Doxycycline (3.36±0.3), Enrofloxacin (3.23±0.2), and Ciprofloxacin (3.18±0.3) figure (2). Also, Staphylococcus aureus was sensitive to Doxycycline (3.32±0.4), Enrofloxacin (3.17±0.3), and Ciprofloxacin (3.12±0.3). It was concluded that the E-coli was the most prominent microflora in the vagina in ewes before and after insertion of sponges. Doxycycline, Enrofloxacin, and Ciprofloxacin are the most effective antibiotics against E-coli and Staphylococcus aureus.

Is it possible to replace eCG by GnRH in the hormonal protocol for timed artificial insemination in ewes during the breeding season?

Hormonal protocols based on progestogens and equine chorionic gonadotrophin (eCG) are efficient for estrus and ovulation synchronization in ewes. Although eCG is indispensable during seasonal anestrus, it may not be necessary during the breeding season. Thus, we tested the hypothesis that GnRH is effective in replacing eCG during the breeding season allowing satisfactory ovulation rate, luteal function and conception rates after timed artificial insemination (TAI). Ewes (n = 134) with a minimum body condition score of 2.5 (0–5 scale) were treated with intravaginal devices (IVD) containing 60 mg of medroxyprogesterone acetate (MPA) for seven days and received 0.26 mg of sodium cloprostenol at the time of IVD removal. In Exp. 1, at IVD removal, ewes (n = 29) were allocated to three groups: eCG (200 IU at IVD removal; n = 10); eCG+GnRH (200 IU eCG at IVD removal and 4 µg of buserelin 36 h later; n = 10); or GnRH (buserelin 36 h after IVD removal; n = 9). Blood samples were collected 2, 6 and 12 days after TAI moment (54 h after IVD removal), for progesterone (P4) analysis. In Exp 2, the ewes were allocated to eCG (n = 10) or GnRH (n = 10) groups, as above described, and ovulation moment was evaluated 54, 66 and 78 h after IVD removal. In Exp 3, TAI was performed in ewes from eCG (n = 45) and GnRH (n = 40) groups using 100 × 106 motile spermatozoa from a pool of semen collected from four rams. In Exp. 1, based on P4 levels, we confirmed that all the ewes ovulated (29/29) and there was no significant effect of group (P = 0.89) or group x day (P = 0.18) on P4 concentration, being observed a significant effect of day (P = 0.0001). In Exp. 2, the maximum DF diameter (P = 0.26) and ovulation moment (P = 0.69) did not differ between groups. In Exp. 3, pregnancy rate was significantly lower (P = 0.02) in GnRH (22.5 %; 9/40) compared to eCG (46.7 %; 21/45). The results indicate that, although ovulation and luteal function were not altered after eCG, eCG+GnRH or GnRH treatment, GnRH alone before TAI cannot be used to replace eCG treatment during the breeding season.

SYNCHRONIZATION OF ESTRUS IN EWES

A group of 15 Awasi ewes were inserted with intravaginal sponges of Veramix plus which were removed thirteen days later. Immediately after removal of the sponges, they were injected with 500 IU of FSH intramuscularly. All ewes were came to estrus within 2-3 days after injection. They were serviced, then, after completing a successful pregnancy, all ewes had twin lambs. : This trial indicates the success of estrus synchronization in ewes.

Efficacy of Intravaginal Lactic Acid Bacteria, Cell-Free Supernatant, or Enrofloxacin on Vaginitis and Fertility in Ewes Synchronized with Progesterone-Based Protocol

An intravaginal sponge impregnated with progesterone is commonly used for estrus induction and synchronization in ewes. Although using an intravaginal sponge containing progesterone positively affects the synchronization rate, varying degrees of vaginitis occur during its application. This study aimed to investigate the impacts of various intravaginal treatment options on the vaginitis severity and pregnancy rate in Merino ewes synchronized with intravaginal sponges impregnated with progesterone. During the breeding period, 589 ewes, aged 2–6, received intravaginal sponges for 14 days. The control group (CON) received no treatment, whereas vaginal sponges absorbed with enrofloxacin (ENR), Lactobacillus plantarum (LAC), or Lactobacillus plantarum supernatant (CFS) were applied in the treatment groups. All groups received 500 IU of equine chorionic gonadotropin intramuscularly. The ENR group showed lower scores in vaginal discharge and sponge odor compared with the CON, LAC, and CFS groups. Although estrus responses did not differ between groups, the pregnancy rate tended to be higher in the ENR group. In conclusion, intravaginal ENR application, but not LAC or CFS, reduced vaginitis severity and tended to increase pregnancy rates in ewes synchronized with intravaginal sponges impregnated with progesterone.

Comparing CIDR with progesterone injections and eCG with human recombinant FSH for synchronizing estrous cycle in ewes.

It is desirable in estrus synchronization in sheep to avoid intravaginal devices and to shorten the program from 14 to 6 days. Moreover, replacement of eCG with safe, cheap, and efficient gonadotropin is in worldwide demand. This study investigates the possibility of replacing eCG with human recombinant FSH (hrFSH) and CIDR with progesterone injections for estrous synchronization in ewes. Assaf and Lacaune ewes (n=170) were divided into two groups and synchronized with either progesterone injections for 6 days or CIDR for 14 days. Ewes assigned in the injection group, received progesterone (37.5 mg; SC) and GnRH analogue (7.5 µg Alarelin acetate; IM) on day 0 of the experiment. On days 3 and 6, ewes received 25 and 12.5 mg progesterone (SC), respectively. On day 6, ewes in both groups received prostaglandin F2α (250 µg Cloprostenol; IM), and were divided into two subgroups to receive either hrFSH (75 IU Follitropin alfa; SC) or eCG (400 IU; IM). On day 7, fertile rams were introduced to ewes for 21 days. Data were analyzed using GLM and Glimmix. There was no difference in the respective lambing rates, prolificacy, and fecundity between CIDR (71.1, 1.63, and 1.16%) and injections (66.7, 1.55, and 1.03%); between eCG (71.4, 1.60, and 1.14%), and hrFSH (66.3, 1.58, and 1.05%, P>0.05). In conclusion, 6-day progesterone injection-based protocol produced similar results to 14-day CIDR program and hrFSH could be an effective alternative for eCG during estrus synchronization in ewes.

Combining two injectable progesterone formulas for estrous synchronization in ewes.

The study aimed to evaluate the effectiveness of combining two injectable progesterone (iP4) formulas for estrous synchronization in ewes and to compare it with traditional intravaginal progesterone devices. Additionally, the study assessed whether the inclusion of GnRH enhances the reproductive outcomes of the iP4 treatment. Two experiments were conducted. In the first experiment, 20 Santa Inês ewes were divided into two groups: one group received intravaginal progesterone devices, and the other received combined long-acting and short-acting iP4. In the second experiment, 30 Corriedale ewes were divided into two groups: one received the combined iP4 with GnRH, and the other without GnRH. Estrous, ovulation, follicular populations, and progesterone concentrations were monitored. The combined iP4 treatment induced an artificial luteal phase and produced reproductive responses similar to those obtained with intravaginal devices. In the first experiment, the iP4 treatment tended to result in more synchronized ovulation compared to the control (P=0.095). In the second experiment, adding GnRH enhanced the quality of the corpus luteum, as indicated by increased diameter and vascularization on Day 23 (P=0.047 and P=0.02, respectively). The combined administration of long-acting and short-acting iP4 effectively synchronized estrous in ewes and showed similar efficacy to traditional intravaginal devices. The inclusion of GnRH improved luteal quality, suggesting potential benefits for reproductive management in ewes. Further studies are needed to evaluate the fertility outcomes of these protocols under field conditions.

Синхронизация на еструса при овце от Синтетична популация българска млечна чрез прогестаген и различни последващи третирания

The aim of the present study was to induce estrus synchronization in ewes after administration of progestagen for 12 days and various subsequent treatments (with FFA, GnRH analogue or no treatment) after cessation of its action. The experiment was conducted in August, 2022, with 27 sheep from the Synthetic Bulgarian Dairy Population. All ewes were treated with vaginal sponges, containing 30 mg FGA (duration of stay - 12 days) and the formation of experimental groups was according to follow-up treatment after sponge removal: I group - experimental animals were treated with 400 UI of PMSG at the time of removal of sponges. II group - the sheep were treated with 1 ml of GnRH analogue, containing busorelin acetate 0.004 mg/ml, 24 hours after sponge removal. III group – no treatment after sponge removal. The next parameters were studied: estrus synchronization rate, fertility and fecundity were studied. The estrus synchronization rate was the highest for I group - 100% and the lowest for II group - 66.67%. Fertility was highest in III group - 87.50%, and lowest in II group - 50.0%. Fecundity was highest in I group - 171.43%, while in other groups it was 133.33% and 128.57%, respectively, for II group and III group. Based on the obtained results, it could be concluded that GnRH analogue treatment, given solely 24 hours after sponge removal, didn’t have the synchronization effect as the classical follow- up treatment with PMSG. No follow-up treatment after sponge removal was better alternative that GnRH treatment.

Comparative evaluation of estrus synchronization protocols on reproductive performance and estrus behavior in Barbados Black Belly sheep.

Estrus synchronization of ewes has been accomplished using several protocols with various degrees of success in improving reproductive efficiency and obtaining the most effective protocol used in sheep farming. This study aimed to compare the effectiveness of three treatment protocols and to record the intensity and duration of estrus signs and pregnancy rate in Barbados Black Belly (BBB) sheep. Thirty-two primipara BBB ewes aged 18-24 months were equally divided into three treatment groups. T1: the ewes were injected intramuscularly with 2 mL Lutalyse (PGF2α) (10 mg) on days 0 and 10. T2: 1 mL Fertiline (50 μg; Gonadorelin acetate) on day 0 and 2 mL lutalyse (10 mg) on day 7. T3: 1 mL fertiline (50 μg) on day 0, 2 mL lutalyse (10 mg) on day 7, and 1 mL Fertiline (50 μg) on day 9. Estrus response was assessed using naturally mating rams and ewes. Pregnancy was determined using ultrasonography between 55 and 80 days after the last hormonal injection. The following estrus signs were noted: Swollen vulva, mucus discharge, sniffing, excitement, loss of appetite, mounting, and rapid tail movement. Of the expressed signs, swollen vulva was most frequent, whereas loss of appetite and mucus discharge were the least overt signs recorded. The estrus response (%), onset (%), and duration (h) in ewe synchronization of the three treatment protocols were 100%, 58.3 ± 23.4%, and 48.0 ± 18.2 h (T1), 100%, 61.7 ± 41.2%, and 45.0 ± 27.0 h (T2), and 37.5%, 32.1 ± 1.7%, and 29.2 ± 1.25 h (T3), respectively. The pregnancy rates were 87.5%, 87.5%, 37.5%, and 50.0% in T1, T2, T3, and T4, respectively. Prostaglandin F2α+PGF2α and GnRH+PGF2α synchronization protocols were more effective in the fertilization of BBB ewes with better expression of estrus signs compared with the GnRH+PGF2α+GnRH (OVS) protocol.

Development and evaluation of an injectable slow-release progesterone formulation for estrus synchronization in ewes out of the breeding season.

This study was aimed at developing a type of slow-release progesterone micro-particles useable in a single intramuscular injection for estrus synchronization in non-breeding season ewes. A total of 66 ewes were randomly assigned into four groups: CIDR (n = 16): exposed to intravaginal CIDR for 12 days, and three experimental groups, i.e., T100 (n = 16), T150 (n = 17) and T200 (n = 17), receiving a single intramuscular injection of 100, 150 and 200 mg slow-release progesterone, respectively. Blood sampling was performed on all ewes at five different times, and the ELISA method measured progesterone levels. No significant differences were observed in progesterone levels among the groups in each sampling time. More than 90% of ewes in the CIDR, T100 and T150 groups and all those in T200 showed estrus behaviour, and the rate was not significantly different between groups. The difference in the mean interval from progesterone treatment to estrus was also insignificant. The parturition rate declined by increasing the dose of injected progesterone; although it was similar in CIDR and T100 groups, it decreased significantly in T150 and T200 . Since our injectable progesterone formulation was successful in the induction and synchronization of estrus in ewes out of the breeding season, it can be applied as an alternative to the conventional progesterone containing intravaginal devices.

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

The study was designed to compare the effect of length of progesterone treatment (6 d vs 10 d vs 14 d) on synchronization efficiency and fertility response in multiparous ewes. The crossbred ewes (30) were equally allotted to three groups designated as short (6 days), medium (10 days) and long-term (14 days) treatment. All the ewes were injected PGF2α 250 μg, intramuscularly 24 h before sponge removal. After the sponge removal ewes were kept with breeding rams for tupping upto 72 h. Although the onset of estrus was more precise in short and long term groups, however overall estrus response rate was highest in short treatment group (90%) followed by long treatment group (70%) and medium treatment group (60%). The pregnancy rates were non-significantly higher for short and medium treatment groups than long treatment group. The progesterone values in pregnant ewes, decreased significantly from day pre-treatment to day 0 followed by significant increase from day 0 to day 10, 17 and 35. In conclusion, short term (6 d) intravaginal progesterone treatment may replace the traditional long term treatment (14 d) for induction of estrous during breeding season. However, the results should be validated in larger number of animals before recommending the protocol.

Approaches of estrous synchronization in sheep: developments during the last two decades: a review.

The objective of the current review was to summarize the protocols used for estrous synchronization in ewes during the last two decades. Progesterone (P4) is a major hormone used in most protocols. P4 in the form of a controlled internal drug releasing (CIDR) device, medroxyprogesterone acetate (MAP), and fluorogestone acetates (FGA) has been used for estrous synchronization. Also, gonadotropins such as equine chorionic gonadotropin (eCG) and gonadotropin-releasing hormone (GnRH) are often administered at the end of P4-based protocols to improve fertility. Moreover, the administration of prostaglandins (PG) and ram effects have been used for estrus induction and synchronization of ewes. The findings of previous studies indicate that the outcome of administering various synthetics P4 analogues (CIDR, MAP, and FGA) in ewes is comparable in terms of estrous synchronization/induction. The supplementation of P4-based protocols with eCG, however, improves the estrus response and pregnancy rate during breeding and non-breeding season. On the other hand, PG is effective for successful estrous synchronization during the breeding season only. Often, two injections of PG are administered either 11 or 14days apart along with P4-based protocols to lyse ovine corpus luteum (CL) when it is receptive to PG i.e., 3days post-ovulation. Alternatively, the "ram effect" has been shown to improve the efficacy of P4-based protocols and can be used as an alternative to eCG in ewes. The current review describes the methods of synchronization and their outcomes during breeding and a non-breeding season in ewes.

The Effect of the Different Artificial Insemination Time Periods on the Pregnancy Rate of Sapudi Ewes

Brucellosis Artificial insemination is required to increase the reproduction rate in ruminant breeding. The artificial insemination success rate in sheep only reaches 47.6%, whereas the proposed ideal rate is 70%. One of the factors influencing the artificial insemination success rates in sheep is improper estrus detection, resulting in no fertilization. The present study aimed to determine the effect of different artificial insemination time periods on the pregnancy rates of Sapudi ewes. The research design was based on a completely randomized design. A total of 20 female Sapudi sheep were divided into four treatment groups with five repetitions (for each group). In addition, the observed variables were artificial insemination time in Sapudi ewes. Estrus synchronization in ewes was conducted by injecting PGF2α. The results of the research indicated that ewes subjected to artificial insemination 6, 12, 18, and 24 hours after estrus had a pregnancy rate of 20%, 100%, 60%, and, 60%, respectively. It can be concluded that the time differences in artificial insemination significantly influence the pregnancy rate in Sapudi ewes’.

Treatments with intravaginal sponges for estrous synchronization in ewes: length of the treatment, amount of medroxyprogesterone, and administration of a long-acting progesterone.

We evaluated if alternative treatments achieve at least similar results as traditional long treatments with intravaginal sponges (IVS) in three experiments considering (1) the use of 6-day treatments associated or not with the administration of PGF2alpha at IVS insertion; (2) a reduction of 50% MAP content in short-term or traditional treatments, with or without change of the IVS 6days after its insertion; and (3) the substitution of IVS for long-time acting injected progesterone associated with the administration of a PGF2alpha. More ewes came into estrus with long than short IVS treatments, independently of the MAP IVS content. Fewer ewes came into estrus if the IVS containing 30mg was replaced 6days after its insertion. The length of the treatment did not affect the conception rate, but the pregnancy rate was greater in 12 than 6days treatments. The administration of long-acting progesterone did not prevent the lower conception rate associated with the use of PGF2alpha and was less effective to synchronize estrus, but the conception rate did not differ from that of 12d IVS treatments. Overall, MAP content could be decreased without affecting the estrous rate; thereafter, the MAP IVS content should be decreased in the commercial devices. Although pregnancy rate was lower using long-acting injected progesterone than with IVS, as the conception rate did not differ, it is interesting to study deeper the use of this treatment, especially if preparations of progesterone with a longer half-life are developed. However considering all the results, the traditional long IVS treatment still provided the best result.

Effects of Melatonin Administration to Pregnant Ewes under Heat-Stress Conditions, in Redox Status and Reproductive Outcome.

Heat stress is a known promoter of reactive oxygen species generation, which may compromise pregnancy and foetal development. Melatonin is a pleiotropic molecule that regulates various processes including pregnancy. Thus, it could be used to ameliorate the redox status of pregnant heat-stressed ewes and the outcome of their pregnancy. Sixty-eight ewes participated in the study, which were allocated into two equal groups, i.e., Melatonin (M) and Control (C) group. All ewes were exposed to heat stress from D0 to D120. In both groups, after oestrus synchronization of ewes, rams were introduced to them for mating (D16). In M group, starting with sponges’ insertion (D0), melatonin implants were administered four-fold every 40 days. Pregnancy diagnosis was performed by means of ultrasonography. Daily evaluation of temperature humidity index (THI), rectal temperature, and breathing rate were performed throughout the study. Blood samples were collected repeatedly from D0 until weaning for assaying redox biomarkers. Milk yield was measured thrice during puerperium. The results showed that melatonin administration throughout pregnancy improved the redox status of heat-stressed ewes and increased the mean number and bodyweight of lambs born per ewe, as well as the milk production. Therefore, melatonin may be used as antioxidant regimen in heat-stressed ewes for improving their reproductive traits.

Hormonal Protocols for the Synchronization and Induction of Synchronized Estrus in Dairy Ewes Kept under Tropical Conditions

Background: Lacaune is an important sheep breed and shows reproductive seasonality which affects dairy product supply. The most common hormonal protocols are based on progesterone-releasing devices in order to reach reproductive activity. Due to international consumer demand for natural, green, and clean methods, such issues encourage the minimal or absent use of synthetic hormones in livestock. In this sense, the present study tested the efficiency of induction and estrus synchronization protocols in lacaune ewes, considering: application interval of synthetic prostaglandin at the breeding season; length of synthetic progesterone exposure; and eCG dose at the outbreeding season.Materials, Methods & Results: In study 1, 52 ewes were submitted to estrus synchronization protocol using two doses of d-cloprostenol 7 or 9 days apart. In study 2, 47 ewes were submitted to estrus induction protocol using an intravaginal device containing 60 mg of medroxyprogesterone acetate maintained for 6, 9, or 12 days. In study 3, 46 ewes were submitted to synchronized estrus induction protocol using intravaginal progesterone device for six days. On the fifth day, d-cloprostenol and 300 IU or 400 IU of eCG were administered. For all studies, signs of estrus beginning/ending were recorded and natural mating was performed. After 30 days, transrectal ultrasound was performed for pregnancy diagnosis. In study 1, groups presented similar rate of estrus behavior (78.8%) and pregnancy (average 75.6%). Meanwhile, compared to G9days (37.8 ± 7.2 h), interval between the second dose of prostaglandin and beginning of estrus was smaller in G7days (31.5 ± 7.8 h). No difference was found among variables studied in study 2 (P > 0.05), nevertheless the SD for the estrus duration was shorter (P < 0.05) in G6days and G12 days when compared with the G9days. Equally, the SD for the interval between sponge withdrawal and beginning and end of estrus was shorter (P < 0.05) in G12days when compared with the G9days. The pregnancy rate, at 30 days, was 71.1%. With regards to study 3, there was no effect of parturition order on sexual behavior between experimental groups (P > 0.05). Equally, no differences were found between variables studied (P > 0.05). The pregnancy rate was 52.2% and number of concepts was 1.5 ± 0.6.Discussion: This paper provides important data on estrus synchronization protocols in dairy sheep kept under tropical conditions. In study 1, both d-cloprostenol protocols were efficient in synchronizing estrus of dairy ewes and reached a fair pregnancy rate. Therefore, it was demonstrated that a d-cloprostenol treatment was a viable alternative to a progestogen treatment, commonly used for estrus synchronization in ewes even during the breeding season. In study 2, all protocols (6, 9 and 12 days of exposure to synthetic progesterone) were efficient in inducing and synchronizing estrus in dairy ewes during the outbreeding season. Therefore, considering not only its efficiency but also the reduction of damage to the vaginal microbiota, the authors strongly encourage the use of the 6-day synthetic progesterone exposure protocol. The third study showed that it is possible to reduce the eCG dose (400 to 300 IU) in dairy ewes while maintaining protocol efficiency, saving 25% of the farmer spending, and avoiding high doses that are related to immune resistance and lower progressive fertility response to IA. In conclusion, the present study verified the efficiency of different hormonal protocols applied for dairy Lacaune ewes kept under tropical conditions, demonstrating that it is possible to decrease: (i) the interval between prostaglandin applications for 7 days apart during the breeding season; (ii) the length of exposure to synthetic progesterone for 6 days; and (iii) the eCG dose to 300 IU during the outbreeding season.

Efficacy of controlled internal drug release (CIDR) treatment durations on the reproductive performance, hormone profiles, and economic profit of Awassi ewes

This study was conducted using 80 multiparous Awassi ewes during the breeding season to compare the effects of controlled internal drug release (CIDR) treatment durations on ewe reproductive performance, hormone profiles, and economic production measures. Ewes were evenly allotted to one of various CIDR treatment durations (3, 6, 9, or 12 d) in four groups (CIDR3, CIDR6, CIDR9, and CIDR12 (control), respectively). The ewes in all groups were injected with 300 IU of equine Chorionic Gonadotropin (eCG) at the time of withdrawal. Blood samples were collected at the time of CIDR insertion and withdrawal, as well as at the time of insemination to measure serum estradiol (E2) and progesterone (P4) concentrations. Timed insemination was performed at 48 h post CIDR withdrawal. The heat detection rate was significantly (P < 0.05) highest in CIDR12 and CIDR9 (100% and 84.21%, respectively). The total pregnancy rate was significantly (P < 0.05) higher in CIDR9 and CIDR6 (68.4% and 60%, respectively) than in CIDR3. Additionally, fecundity was significantly (P < 0.05) lowest in CIDR3. At insemination, the P4 level was significantly (P < 0.05) lower in CIDR9 and CIDR12 than in the other groups. At insemination, the E2 level was higher (P < 0.05) in CIDR6 followed by that in CIDR3 and CIDR9, and then in CIDR12. The total variable cost, total cost, the return and net profit were higher in CIDR6 than in other groups. In conclusion, although use of CIDR for 6, 9, and 12 d is efficient to synchronize estrus in ewes with similar reproductive performance, CIDR use for 6 d provided higher return and net profit than that for 9 or 12 d. CIDR use for 3 d is inefficient for estrus synchronization in ewes.

Efficacy of anti-microbial agents on vaginal microorganisms and reproductive performance of synchronized estrus ewes

Objective: To isolate and identify microflora and fungal species at different phases during estrus synchronization of ewes and estimate their prevalence; compare the effectiveness of antimicrobial administration to intravaginal sponge on the changes in the vaginal microorganisms and reproductive performance. Methods: Sixty Egyptian ewes were allocated into three equal groups (G: 1, 2 and 3). G1 was inserted with vaginal sponge containing medroxy- progesterone acetate and served as control; without antimicrobial additive. The other two groups were treated as G1, but sponges were previously injected with ciprofloxacin (G2), while sponges of G3 were injected with ciprofloxacin and clotrimazole. Vaginal swabs were collected from each treated ewe, prior sponge insertion, at sponge withdrawal and 48 h later for microbiological investigation and bacterial count. On the day of sponge removal, 300 IU/eCG was administered for each treated ewe. The identified bacterial strains before sponge insertion were tested for sensitivity with antimicrobial disks. Results: Bacterial isolates before sponge insertion were more sensitive to ciprofloxacin. Frequencies of ewes in estrus; the interval from sponge withdrawal to onset estrus and the duration of estrus were statistically similar among treated groups. The pregnancy rate in G2 (100.0%) was higher than G1 (66.7%) and G3 (82.4%). The total bacterial count before sponge insertion was similar between all treatments and increased significantly in all groups on the day of sponge withdraw. The prevailing bacteria on D0, D14 and 48 h after sponge removal for all treated groups were Staphylococcus spp. followed by Escherichia coli. Regarding to fungus species, percentages of isolation increased from 5.00% (before sponge insertion) to 100.00% and 88.89% at sponge withdraw for G1 and G2, respectively. In G3, the fungus was declined from 10% (before sponge insertion) to 5% (at sponge removal). Conclusions: The concomitant treatments by antimicrobial to the vaginal sponge which used for estrus synchronization in ewes can improve reproductive performance.

REPRODUCTIVE PERFORMANCE OF MORADA NOVA EWE SUBJECTED TO ESTRUS INDUCTION BY MALE EFFECT

This study aimed to evaluate the reproductive performance of crossbred sheep (New Address) nulliparous, primiparous and pluriparous, subjected or not to the male effect. There were used 79 ewes and two rams (one vasectomised ram – teaser ram) and a breeder). In the first year, the females were subjected to the male effect (ME: male effect), in the following year, there has been no application of this method (AME: absence of male effect). Ewes subjected to ME showed a higher synchronization (P &lt;0.05) compared to AME females. Nulliparous and primiparous ewes subjected to ME exhibited a higher synchronization, in relation to ewes in the absence of male effect. When specified by birth order, there were superior results (P &lt;0.05) within the same method (AME) for prolificacy index and twinning rate for pluriparous females relative to nulliparous and primiparous. There were also significant differences (P &lt;0.05) for the use of the male effect, but with superiority of pluriparous and primiparous females when compared to nulliparous. Between the methods, ME primiparous females (72.22%) were superior (P &lt;0.05) to AME ewes (33.33%) for twinning rate. Thus, it can be concluded that the male effect is feasible for estrus synchronization in ewes up to the first lambing birth, besides possibly causing better ovulation rate, due to better results of twinning rate and prolificacy index.

Estrus synchronization schemes and application efficacies in anestrus lanzhou fat-tailed ewes

ABSTRACTThis study aims to investigate the estrus efficacy of FIS (fluorogestone intravaginal sponges)/eCG (equine chorionic gonadotropin) and cloprostenol treatments to establish the optimum protocols for estrus synchronization in ewes. Forty-two ewes were assigned into groups A (FIS/eCG group) and B (CLO (cloprostenol) group). Each group was randomly divided into three subgroups (n = 7) according to the dose of eCG (ECG1, ECG2 and ECG3) or cloprostenol (CLO1, CLO2 and CLO3). The estrus rates, lambing rates and average litter sizes were accounted. Serum concentrations of progesterone (P4), follicle-stimulating hormone (FSH) and luteinizing hormone were determined. Selected optimum schemes were employed in 636 ewes in four sheep farms. Estrus rates of groups A and B were 85.72% and 57.14%. Estrus onset times (EOTs) were 53.91 ± 12.26 and 46.41 ± 4.65 h for groups A and B. EOT of ECG1 was longer than that of CLO3 (P < .05). Lamb numbers, lambing rate and litter size of group B were lower than those of group A. The maximum and minimum lambing rates were calculated in ECG3 and CLO1 (157 vs. 57). On day 11, higher P4 values (P < .05) were determined of ECG3 and CLO1 compared to CLO2 and CLO3 subgroups. FSH concentration of ECG1 was significantly higher than that in group B (P < .05). Application results showed that estrus rate, pregnancy rate and lambing rates of ECG3 and CLO3 protocols were 95.97% vs. 70.91%, 91.37% vs. 88.89% and 149.87% vs 132.69% (P < .05), respectively. FIS/eCG and cloprostenol improved estrus synchronization. Injection of 400 IU eCG after FIS withdrawal was an optimum protocol for estrus synchronization of ewes.

Development of starch based mucoadhesive vaginal drug delivery systems for application in veterinary medicine

The aim of this study was to prepare and evaluate the mucoadhesive, biocompatible and biodegradable progesterone containing vaginal tablets based on modified starch copolymers for the estrus synchronization of ewes. Starch-graft-poly(acrylic acid) copolymers (S-g-PAA) were synthesized and characterized. The vaginal tablets were fabricated with S-g-PAA and their equilibrium swelling degree (Qe) and matrix erosion (ME%) were determined in lactate buffer solution. In vitro, mucoadhesive properties of the tablets were investigated by using ewe vaginal mucosa and in vivo residence time were also investigated. In vitro and in vivo progesterone release profiles from the tablets were compared with two commercial products. Tablet formulation containing wheat starch based grafted copolymer (WS-g-PAA)gc indicated promising results and might be convenient as an alternative product to the commercial products in veterinary medicine.