25 ADDITION OF FSH, IN CONTRAST TO eCG, DOES NOT INCREASE PREGNANCY RATES IN ANESTROUS NELLORE (BOS INDICUS) COWS TREATED WITH FIXED-TIME AI PROTOCOL

2010 ◽  
Vol 22 (1) ◽  
pp. 170 ◽  
Author(s):  
L. A. Lima ◽  
V. G. Pinheiro ◽  
J. R. Cury ◽  
C. M. Barros
Keyword(s):  
Pregnancy Rate ◽  
Buenos Aires ◽  
Animal Health ◽  
Bos Indicus ◽  
Fixed Time ◽  
Sao Paulo ◽  
Pregnancy Rates ◽  
Control Group ◽  
São Paulo ◽  
Intravaginal Device

There are reports in the literature indicating that use of eCG improves pregnancy rates in Bos indicus anestrous cows treated with a progesterone-based fixed-time AI (FTAI) protocol. More recently, replacement of eCG by FSH in FTAI protocols was reported to have beneficial effects (Bos indicus) or no effect (Bos taurus) on pregnancy rates. In the present experiment the effects of eCG and FSH on pregnancy rates were compared in an FTAI protocol. Primiparous lactating Nellore cows (40 to 80 days postpartum, n = 421) with a body condition score of 2.5 to 3.0 (on a 1 to 5 scale) were randomly allocated in 3 groups: Control (CTR), eCG, and FSH. In the control group, all animals received a progesterone (P4)-releasing intravaginal device (1.55 g, PRID®, Ceva Sante Animale S.A., Libourne, France) and 2.5 mg of estradiol benzoate (EB, i.m. Estrogin®, Farmavet, São Paulo, Brazil), on Day 0 (D0). Eight days later (D8), at the time of the intravaginal device withdrawal, PGF2α (150 μg, D-cloprostenol, i.m. Prolise®, ARSA S.L.R., Buenos Aires, Argentina) was administered. Twenty-four hours after PRID removal, cows were treated with EB (1.0 mg, i.m.), and FTAI was done 30 to 36 h later. In the eCG and FSH groups, the cows were treated with 20 mg of FSH (Folltropin-V®, i.m. Bioniche, Belleville, Canada) or400IU of eCG (Novormon®, i.m. Syntex, Buenos Aires, Argentina), respectively, at the time of PGF2α administration. Ovarian ultrasonography (Aloka SSD 500, 7.5-MHz probe, Aloka, Tokyo, Japan) was performed 10 days prior to and at the beginning of FTAI protocol to select the animals in postpartum anestrous (absence of CL in both examinations). The pregnancy diagnosis was performed by ultrasonography 30 days after FTAI. Data were analyzed by logistic regression (SAS Institute, Cary, NC, USA). Cows treated with eCG had a higher pregnancy rate (41.5%, 95/229; P < 0.05) than those treated with FSH (22.7%, 22/97) or in the control group (26.3%, 25/95). Pregnancy rates of animals treated with FSH did not differ (P > 0.05) from those in the control group. These results indicated that, in lactating primiparous anestrous Nellore cows, the use of eCG in a FTAI protocol improves the pregnancy rate, whereas FSH has no beneficial effect. V. G. Pinheiro received a fellowship from FAPESP (São Paulo, Brazil). The authors are grateful to Ceva Animal Health for providing the intravaginal devices (PRID®) used in this experiment.

13 USE OF A NEW INTRAVAGINAL DEVICE TO RELEASE PROGESTERONE IN FIXED-TIMED ARTIFICIAL INSEMINATION IN NELLORE COWS (BOS TAURUS INDICUS)

2010 ◽  
Vol 22 (1) ◽  
pp. 164
Author(s):  
F. A. Braga ◽  
F. J. D. Pardo ◽  
P. H. Miguez ◽  
A. Kehrle ◽  
J. R. V. Pimentel ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Artificial Insemination ◽  
Body Condition Score ◽  
Estradiol Benzoate ◽  
Sao Paulo ◽  
Pregnancy Rates ◽  
Control Group ◽  
São Paulo ◽  
Effect Of Treatment ◽  
Intravaginal Device

Artificial insemination results can be improved using fixed-timed AI (FTAI). Currently, progesterone release devices, indispensable in FTAI procedures, such as DIB® (Schering-Plough, Kenilworth, NJ, USA), are made of silicone, a nonbiodegradable biocompatible polymer. Recently, biodegradable progesterone (P4)-releasing devices made of poly(3-hydroxy)butyrate-valerate copolymer (PHB-V) and poly-ϵ-caprolactona (PCL) have been developed. To investigate the efficiency on pregnancy rate of FTAI programs using a new intravaginal device made of PHB-V (Progestar®, Innovare, São Paulo, Brazil), 240 Nellore (Bos indicus) cows, between 3 and 8 years of age, were randomly assigned to 2 experiments. In experiment 1, new P4 devices DIB (control group, DIB1; n = 60) were compared with PHB-V (Progestar1; n = 76); in experiment 2, previously used DIB (DIB2; n = 52) and PHB-V (Progestar2; n = 52) devices were compared. All groups were treated with 2 mg of estradiol benzoate i.m. (Innovare) and received the intravaginal device according to group (Day 0). Together with P4 device withdrawal (Day 8) all animals received 300IU of eCG i.m. (Novormon®, Schering-Plough) and 150 μg i.m. of D-cloprostenol (Croniben®, Biogenesis-Bagó, Buenos Aires, Argentina). On Day 9, all cows were treated with 1 mg of estradiol benzoate and the FTAI was performed 30 h later. The data were submitted to ANOVA (PROC GLM of SAS, SAS Institute, Cary, NC, USA), separating as causes of variance the effect of treatment, postpartum period (PPP1-45 until 70 days and PPP2-71 until 90 days), body condition score (BCS4, BCS5, and BCS6 using a 1 to 9 scale), cyclicity (cycling and noncycling) and clean-up bulls (5 bulls nominated with numbers 1 to 5). Significant differences were considered to have P < 0.05. In experiment 1, interactions were not significant, there was no effect of treatment on FTAI (DIB1: 66.7% v. Progestar1: 65.8%) or breeding season pregnancy rates (BSPR; DIB1: 95.0% v. Progestar1: 94.7%) and no effect of other variables on FTAI pregnancy rates (FTAIPR) and BSPR. In experiment 2 there was no effect of treatment on FTAIPR (DIB2: 61.6% v. Progestar2: 55.8%) and BSPR (DIB2: 94.2% v. Progestar2: 88.5%). As ANOVA indicated a significant effect of clean-up bulls on BSPR, Tukey test was used to split it up. A bull of the Progestar2 group had lower performance (41.7%) causing the difference (albeit nonsignificant) on BSPR. This experiment showed that Progestar and DIB had the same efficiency on pregnancy rate and both treatments have the potential to produce FTAIPR >50% and BSPR >90%. Fapesp-Fundação de Amparo à Pesquisa do Estado de São Paulo. CNPq-Conselho Nacional de Desenvolvimento Científico e Tecnológico.

32 USE OF HORMONE WITH ACTION FOLLICLE-STIMULATING IN OVULATION SYNCHRONIZATION OF CROSSBRED HOLSTEIN-GYR COWS

2010 ◽  
Vol 22 (1) ◽  
pp. 174
Author(s):  
V. A. Nascimento ◽  
G. S. Moura ◽  
M. Dias ◽  
F. A. Oliveira ◽  
A. R. Dias ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Body Condition ◽  
Buenos Aires ◽  
Body Condition Score ◽  
Animal Health ◽  
Live Weight ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Sao Paulo ◽  
São Paulo

The objective of this study was to evaluate the administration of the follicle-stimulating hormone (FSH-p) or equine chorionic gonadotropin (eCG) in protocols of ovulation synchronization. One hundred forty-nine crossbred Holstein-Gyr cows were used in 2 properties in Minas Gerais and 3 treatments: TControl (n = 49 cows), Day 0: insert of a progesterone device (Primer®, Tecnopec, São Paulo, Brazil) + 2 mg of estradiol benzoate (RIC-BE®); Day 8: removal of Primer + 112 mg of D-cloprostenol (Prolise®, ARSA SRL, Buenos Aires, Argentina) + 1 mg of estradiol benzoate and fixed-time artificial insemination (FTAI) accomplished 44 h after the removal of Primer; TFSH (n = 50 cows), similar to TControl, but on Day 8, 15 mg of FSH-p (Folltropin®, Bioniche Animal Health) was administered; TeCG (n = 50 cows), similar to TControl, with administration on Day 8 of 300 IU of eCG (Novormon®, Syntex SA, Buenos Aires, Argentina). Cows that returned to estrus 14 to 28 days after the FTAI were inseminated once again. For all statistical analysis, we used the program SAS 9.0 (2002; SAS Institute Inc., Cary, NC, USA) at 5% probability. Quantitative variables (live weight, days postpartum, follicular average per cow) were analyzed by variance, and body condition score by Friedman test. The pregnancy rates were submitted to logistic analysis considering the effect of local experimental factors and were analyzed by Spearman correlation among the variables studied and the pregnancy rate. There was no difference (P > 0.05) between treatment for pregnancy rate in FTAI protocols (TControl = 40.82%; TFSH = 38.00%; TeCG = 26.00%), in the first insemination after FTAI (TControl = 56.25%; TFSH = 70.59%; TeCG = 68.42%), and in FTAI plus first insemination after FTAI (TControl = 59.18%; TFSH =62.00%; TeCG = 52.00%), as well as for the estrus repetition (TControl = 55.17%; TFSH = 54.84%; TeCG = 51.35%) and the correlation (P > 0.05) among the pregnancy rate and postpartum period, milk production, body weight and body condition. No effect was observed on the pregnancy rate by the addition of the hormones FSH and eCG in the protocol of ovulation synchronization in crossbred Holstein-Gyr cows; however, reinsemination in the period from 14 to 28 days after FTAI increased the pregnancy rate. CNPq; FAPEMIG; TECNOPEC/São Paulo, Brazil.

116 PREGNANCY RATES AFTER ADMINISTRATION OF EQUINE CHORIONIC GONADOTROPIN (eCG) AT PROGESTERONE INTRAVAGINAL DEVICE REMOVAL AND 14 DAYS AFTER FIXED-TIME AI IN BEEF CATTLE

2011 ◽  
Vol 23 (1) ◽  
pp. 163 ◽  
Author(s):  
R. Núñez ◽  
T. de Castro ◽  
L. Cutaia ◽  
G. Bó ◽  
A. Menchaca
Keyword(s):  
Beef Cattle ◽  
Pregnancy Rate ◽  
Body Condition Score ◽  
Fetal Loss ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Control Group ◽  
Device Removal ◽  
Embryo Survival ◽  
Intravaginal Device

An important proportion of embryonic deaths in cattle occur during the critical period of embryo development and maternal recognition of pregnancy. High serum progesterone concentrations during this period are associated to higher embryo survival, and the use of eCG could enhance luteal activity. Two experiments were carried out to evaluate the effect of administering eCG at the time of removal of a progesterone-releasing device and 14 days after fixed-time artificial insemination (FTAI) in beef cattle. Multiparous suckled cows between 60 and 90 days postpartum (n = 297; Exp. 1), and two-year old prepuberal heifers (n = 689; Exp. 2) with a body condition score (BCS) between 3.5 and 5 (1 to 8 scale) were used. At the beginning of the experiments, none of females used had a corpus luteum detected by ultrasonography. Females received an intravaginal device containing 0.5 g progesterone (DIB 0.5, Syntex, Buenos Aires, Argentina) and 2 mg oestradiol benzoate i.m. (Benzoato de Oestradiol, Syntex). Eight days later, 500 μg of cloprostenol (Ciclase DL, Syntex) and 0.5 mg oestradiol cypionate (Cipiosyn, Syntex) were given i.m. and devices were removed; FTAI was performed 52 to 56 h after DIB removal. At the time of device removal, the animals were randomly allocated to 4 groups, to receive 400 IU of eCG i.m. (Novormon, Syntex) or placebo at device removal and/or 14 days after FTAI, in a 2 × 2 factorial design. Control group did not receive eCG. In Exp. 1, nose plates were placed on calves on the day of DIB insertion and left for 10 days in order to prevent suckling. Pregnancy diagnosis was performed by ultrasonography at 30 and 60 days after FTAI. Data were analysed by logistic regression. Pregnancy rate at 30 days after FTAI was affected by treatment (P < 0.05; Table 1). Late embryonic/fetal loss rates (non-pregnant females at 60 days after FTAI over those pregnant at 30 days) were 1.6% (3/182) for cows in Exp. 1 and 4.8% (14/292) for heifers in Exp. 2; no differences were detected among groups. In conclusion, administration of 400 IU of eCG at device removal increases pregnancy rate, both in anestrus cows and heifers. However, the administration of a second dose of eCG 14 days after FTAI suggests a possible effect on embryo survival within the first 30 days of pregnancy in cows but not in heifers. Further studies are required to confirm these results. Table 1.Pregnancy rates after administration of eCG at time of progesterone device removal and/or 14 days after insemination in beef cattle Supported by Syntex.

scholarly journals Evaluation of pregnancy rates of Bos indicus cows subjected to different synchronization ovulation protocols using injectable progesterone or an intravaginal device

2016 ◽  
Vol 37 (6) ◽  
pp. 4149
Author(s):  
Jefferson Tadeu Campos ◽  
Fábio Morotti ◽  
Camila Bortoliero Costa ◽  
Larissa Zamparone Bergamo ◽  
Marcelo Marcondes Seneda
Keyword(s):  
Pregnancy Rate ◽  
Bos Indicus ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Estrus Cycle ◽  
Device Removal ◽  
Alternative Source ◽  
Group Iii ◽  
Group I ◽  
Intravaginal Device

This study evaluated the pregnancy rate in Nelore cows (Bos indicus) that were subjected to fixed-time artificial insemination (FTAI) using different protocols consisting of injectable progesterone (P4) or an intravaginal device (impregnated with P4). Multiparous cows 72-84 months in age, 30-45 days postpartum, were selected on the basis of the absence of a corpus luteum (CL) and follicles < 8 mm after transrectal palpation and ultrasound examinations. On a random day of the estrus cycle (D0), the selected animals (n = 135) were randomly assigned to one of three experimental groups (n = 45 each). Group I (injectable P4/FTAI 36 hours) received 250 mg of injectable P4 and 2 mg EB on D0; on D7, they received 500 µg of cloprostenol; on D8, 300 IU of eCG and 1 mg of EB were administered; and finally, FTAI was performed 36 hours after the application of EB. Group II (injectable P4/FTAI 48 hours) received the same protocol as Group I, except that the FTAI was performed 48 hours after ovulation induction. The animals of Group III (Control/CIDR) received a conventional protocol for FTAI using an intravaginal device (D0: P4 and 2 mg EB; D8: device removal, 500 µg cloprostenol, 300 IU eCG, 1 mg EB; and FTAI performed 48 hours after removal of the device). The results showed that cows synchronized with the conventional protocol for FTAI (Control/CIDR) had a higher pregnancy rate (60 %, 27/45) than those synchronized with an injectable P4/FTAI 36 hours (33.33 %; 15/45, P = 0.010). However, the group receiving injectable P4 group/FTAI 48 hours had a similar pregnancy rate (48.9 %; 22/45; P = 0.290) when compared to both the group receiving the conventional protocol and that receiving injectable P4/FTAI 36 hours (P = 0.134). Although the injectable P4 may affect pregnancy rate with the FTAI performed in 36 hours, we found similar pregnancy rates from cows inseminated 48 hours after induction ovulation, considering injectable or intravaginal P4. Therefore, we suggest that injectable P4 represents an alternative source of progesterone for synchronization of cattle for FTAI.

scholarly journals Influence of Injectable Progesterone on the Pregnancy Rate of Heifers Receiving Bovine Embryos

2020 ◽  
Vol 48 ◽  
Author(s):  
Caio Cezar Da Silva ◽  
Hélton Aparecido Garcia Gregianini ◽  
Jennifer Teodoro Ferreira Gregianini ◽  
José Antônio Dell’Aqua Junior ◽  
Jefferson Viana Alves Diniz ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Embryo Transfer ◽  
Physiological State ◽  
Bos Indicus ◽  
Fixed Time ◽  
Treated Group ◽  
Pregnancy Rates ◽  
Control Group ◽  
Bovine Embryos

Background: In vitro embryo production (IVEP) allows the spread of superior animal genetics, but pregnancy rates show a high variability with this biotechnique. In the initial stage of pregnancy, progesterone plays a fundamental role in uterine preparation, acting on embryonic growth, implantation, and development. However, on the day of the IVEP transfer to the recipients, progesterone levels may be lower than that expected, influencing the uterine environment and, consequently, the pregnancy rate. Therefore, the objective of this study was to evaluate the pregnancy rate in heifers after the administration of injectable progesterone (P4) in the fixed-time embryo transfer (FTET) protocol.Materials, Methods & Results: The experiment was conducted inside a rural property near the city of Rio Branco, Acre, Brazil. The experimental group consisted of 232 animals, including 78 zebuine (Bos indicus) and 154 mixed (½ blood B. indicus and ½ blood B. taurus) animals, aged between 16 and 24 months, with a mean weight of 300 and 330 kg for zebuine and mixed animals, respectively. The selected animals were previously synchronized using the progesterone-estrogen-prostaglandin-estrogen protocol. Embryo transfer was performed on day 18 of the protocol, which was 9 days after the removal of intravaginal progesterone implant. On day 15 of the protocol, that is, 144 h (6 days) after the device removal, the animals were randomly distributed into two experimental groups: Control Group (CG; 0.5 mL of 0.9% saline solution, intramuscular) and Treated Group (P4G; 0.5 mL of injectable P4, 150 mg, intramuscular). Chi-square test was used for the statistical analysis of the pregnancy rate at a 5% probability. After 23 days of embryo transfer, pregnancy was diagnosed by ultrasonography. The general pregnancy rate, considering all groups (CG and P4G) and breeds included, was 55.17% (128/232). The pregnancy rates of the P4G and CG groups, regardless of breeds, were 55.08% (65/118) and 55.26% (63/114), respectively, with no statistical difference (P = 0.8344). Angus animals presented a similar pregnancy rate in the P4G and CG groups of 54.93% (39/71) and 57.83% (48/83), respectively. Furthermore, similar results were found for the Nellore breed, with no difference in pregnancy rate between the CG (55.81%, 24/43) and P4G (48.57%, 17/35) groups.Discussion: The strategy of using P4 to increase the pregnancy rate is very widespread in fixed-time artificial insemination (FTAI) protocols, although differences still exist. The literature presents zero or negative effects, as in this study, when exogenous P4 was used to increase endogenous P4 concentrations and, consequently, the pregnancy rate. However, some studies demonstrated the beneficial effects of increasing blood P4 concentrations, and that the increased fertility depends on the method and time of P4 supplementation and the animal’s physiological state. In this context, the fact that the injectable progesterone supplementation did not increase the pregnancy rate in this study is justified mainly by factors such as the animal category used (heifers), time of P4 supplementation (day 4 after ovulation), biotechnology used (FTET), and the heterogeneous characteristics related to phases of the estrous cycle of heifers. Supplementation with 150 mg of injectable long-acting progesterone intramuscularly did not interfere in the pregnancy rate of Angus and Nellore heifers receiving bovine embryos.

209 EXPRESSION OF GENES RELATED TO OVULATORY CAPACITY (LHR AND AGTR2) IN GRANULOSA CELLS FROM SUPERSTIMULATED OR NOT SUPERSTIMULATED ANGUS COWS

2014 ◽  
Vol 26 (1) ◽  
pp. 218 ◽  
Author(s):  
E. Lucacin ◽  
A. R. Pupulim ◽  
P. K. Fontes ◽  
E. M. Razza ◽  
M. F. Machado ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Target Genes ◽  
Animal Health ◽  
Treatment Protocol ◽  
Sao Paulo ◽  
Mrna Abundance ◽  
Control Group ◽  
Mrna Levels ◽  
São Paulo ◽  
Intravaginal Device

Multiple ovulation and embryo transfer (MOET) has contributed to genetic improvement of Brazilian cattle and the P36 superstimulatory treatment protocol has been used successfully in MOET programs. Recently, increased mRNA levels of LH receptor (LHR) and angiotensin II receptor type 2 (AGTR2) have been reported in granulosa cells (GC) of superstimulated Nelore cows using P36 protocol and the efficacy of the P36 protocol has been investigated with the addition of a LH stimulus (eCG or LH), on the last day of treatment. We aimed to evaluate mRNA abundance of AGTR2 and LHR, related to ovulatory capacity, in GC of superstimulated Angus cows by different variations of the P36 protocol. Multiparous Angus cows (n = 37) were randomly assigned to four groups: control, P36, P36+eCG, and P36/FSH+LH. The control group (non-superstimulated cows, n = 7) received an intravaginal device containing progesterone (1.0 g; Primer®; Agener Animal Health, São Paulo, SP, Brazil) and 2.5 mg of oestradiol benzoate (EB; RIC-BE®; Agener Animal Health; IM) on a random day of the oestrous cycle (Day 0). After 8 days (Day 8) cows were treated with PGF2α (150 mg d-cloprostenol; Prolise®; Agener Animal Health; IM; 7:00 a.m.) and the intravaginal device was removed (7:00 p.m.). Cows from P36 group (n = 10) received the intravaginal device and 2.5 mg of EB at the beginning of the protocol (Day 0). Starting 5 days later (Day 5), 200 mg pFSH (Folltropin®; Bioniche Animal Health, Belleville, ON, Canada) was administered twice daily by IM injections over 4 days; on Day 7, PGF2α was administered and the intravaginal device was removed 36 h later (Day 8, 7:00 p.m.). Groups with the addition of a LH stimulus (eCG or LH administration) were submitted to the P36 protocol with replacement of the last two FSH doses by 200 IU eCG (P36+eCG; Novormon®, MSD Animal Health, São Paulo, SP, Brazil, IM; n = 10) or 2 mg pLH concomitant with the last two doses of FSH (P36/FSH+LH; Lutropin®, Bioniche Animal Health, IM; n = 10). Cows in all groups were slaughtered on Day 9, 12 h after progesterone-device removal and ovaries were transported on ice to the laboratory immediately after slaughter. Non-superstimulated dominant follicles and superstimulated follicles were dissected from the ovaries to obtain GC and total RNA was extracted. Amplification of housekeeping (peptidyl-prolyl isomerase A; PPIA) and target genes was performed by real-time RT–PCR according to the Sybr Green protocol. Relative gene expression was determined by Pfaffl's equation. The mRNA abundance was compared by Tukey's test and the significance level was P < 0.05. In GC, the mRNA abundance (mean ± s.e.m.) of LHR and AGTR2 was higher in the control group (1.02 ± 0.24 and 3.76 ± 1.07, respectively; P < 0.05) when compared with the superstimulated groups: P36 (0.33 ± 0.24 and 1.02 ± 0.21), P36+eCG (0.42 ± 0.10 and 1.40 ± 0.33) and P36/FSH+LH (0.38 ± 0.07 and 1.45 ± 0.49). In conclusion, the superstimulatory treatments decrease mRNA levels of LHR and AGTR2. We acknowledge CAPES for E. Lucacin's scholarship and FAPESP–São Paulo Research Foundation for grant number 2011/50593-2.

28 COMPARISON OF NEW v. PREVIOUSLY USED INTRAVAGINAL DEVICE FOR A PROGESTERONE-BASED TIMED ARTIFICIAL INSEMINATION PROTOCOL IN NELORE (BOS INDICUS) COWS

2010 ◽  
Vol 22 (1) ◽  
pp. 171 ◽  
Author(s):  
J. H. Martins ◽  
M. I. S. Silva ◽  
G. A. Crepaldi ◽  
W. O. Melo ◽  
J. R. S. Torres-Júnior
Keyword(s):  
Pregnancy Rate ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Sao Paulo ◽  
Pregnancy Rates ◽  
São Paulo ◽  
Device Removal ◽  
Serum Progesterone ◽  
New Device ◽  
Lactating Cows

The objective of this study was to evaluate the effect of reutilization of intravaginal progesterone devices on pregnancy rate of lactating and nonlactating Nelore cows submitted to fixed-time AI (FTAI). The study used 684 lactating cows (50 to 70 days postpartum) and 361 nonlactating cows (210 to 240 days postpartum). At random stages of the estrous cycle (Day 0), all animals received 2 mg of estradiol benzoate (Estrogin®, Farmavet, São Paulo, Brazil) and the animals of each category (lactating or nonlactating) were allocated in 1 of 2 treatments (new or used). Thus, the 4 groups consisted of lactating/new, lactating/used, nonlactating/new and nonlactating/used. The animals of lactating/new and nonlactating/new groups received a new intravaginal progesterone device (1 g of P4, DIB®, Intervet/Schering-Plough, São Paulo, Brazil) and the cows of lactating/used and nonlactating/used groups received a similar device that had previously been used for 8 days. At the time of P4 device removal (Day 8), the cows were treated with 150 μg of cloprostenol (Preloban®, Intervet/Schering-Plough), 1 mg of estradiol cypionate (ECP®, Pfizer, São Paulo, Brazil), and 300 IU of eCG (Folligon®, Intervet/Schering-Plough). The cows were FTAI on Day 10 (48 to 52 h after device removal). To evaluate the pregnancy rate, an ultrasonographic examination (CHISON 500VET, USP Brasil Eletromedicina, São Paulo, Brazil) was performed 30 days after the FTAI. Data were analyzed using the GENMOD procedure of SAS (SAS Institute, Cary, NC, USA).There was no interaction between treatment and BCS, AI bull, or technician. The pregnancy rates for the groups were 155/300 (51.7%a for lactating/new, 200/384 (52.1%a for lactating/used, 52/154 (33.8%b for nonlactating/new, and 96/207 (46.2%a for nonlactating/used (P = 0.0007). A reduction in pregnancy rate for nonlactating cows occurred when the intravaginal progesterone device was new. Although serum progesterone was not measured in the current trial, it is very likely that this finding might be explained by the high cyclicity rates in beef cows after weaning (210 days postpartum) and by the presence of CL producing additional support of progesterone besides the high P4 from the new device (Baruselli et al. 2004 Anim. Reprod. Sci. 82, 479-486). Many researchers found that greater circulating progesterone concentrations during progesterone implant treatment reduced LH pulsatility, LH follicular receptors, and follicular growth (Ireland and Roche, 1982 J. Reprod. Fertil. 64, 295-302). Furthermore, it seems likely that the presence of smaller-sized ovulatory follicles might contribute to ovulation failures, delayed ovulation, smaller CL area, and decrease in the pregnancy rate (Carvalho et al. 2008 Theriogenology 69, 167-175). In conclusion, lactating cows can be fixed-time inseminated using a new or a previously used DIB® as progesterone source. However, for nonlactating cows, a previously used device may increase pregnancy rates. USP Brasil Eletromedicina, ABS Pecplan and Fazendas Reunidas Rio Bravo.

scholarly journals 215SUCCESSFUL OUT-OF-BREEDING SEASON ESTRUS SYNCHRONIZATION FOLLOWED BY FIXED TIME INSEMINATION IN WATERBUFFALO (BUBALUS BUBALIS)

2004 ◽  
Vol 16 (2) ◽  
pp. 229 ◽  
Author(s):  
R.M. Züge ◽  
U. Rodacki ◽  
A.T. Grandi ◽  
J.M.J. Aerts ◽  
P.E.J. Bols
Keyword(s):  
Breeding Season ◽  
Buenos Aires ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Sao Paulo ◽  
Reproductive Efficiency ◽  
São Paulo ◽  
Estrus Synchronization ◽  
The Impact ◽  
Synchronization Protocol

The most important barrier to the increase of buffalo productivity is an overall poor reproductive efficiency, characterized by late sexual maturity, seasonal anestrus and long periods of postpartum ovarian inactivity resulting in extended calving intervals and poor expression of estrus behavior (Singh J et al., 2000, Anim. Reprod. Sci. 60–61, 593–604). Buffaloes are seasonal breeders with the highest reproductive activities during winter (short day lengths) and a high frequency of anestrus during the summer months (Singh G et al. 1985, Ind. J. Anim. Res. 19, 57–60). Recent research demonstrated that a combination of progesterone, estradiol benzoate and equine chorionic gonadotropin (eCG) was effective for estrus induction and synchronization in buffalo heifers under Mediterranean conditions (Barile et al. 2001, Livestock Prod. Sci. 68, 283–287). The aim of the present study was to investigate the impact of an estrus synchronization protocol on reproductive efficiency of water buffalo during out of the normal breeding season. A total of six heifers (21 to 23 months of age) and three cows (5, 6 and 18 years of age) were enrolled in an estrus synchronization protocol lasting for 12 days. All animals were kept under tropical conditions in the coastal part of Paraná (Antonina), about 450km south of São Paulo. The experiment was performed in December, 2002, during the Brazilian summer season, when reproductive efficiency of buffaloes is greatly reduced. On the first day of the protocol (Day 0), animals were implanted with an intravaginal device containing 1g of progesterone (DIB, Syntex SA, Buenos Aires, Argentina) and injected with 10mg estradiol benzoate (Estrogin, Famavet, São Paulo, Brazil). On Day 9, the DIB implant was removed and the animals received 150μg (i.m.) of cloprostenol (Prolise, Syntex SA, Buenos Aires, Argentina) and 2500 IU of eCG (Novormon, Syntex SA, Buenos Aires, Argentina). On Day 11, all animals received 1500 IU of hCG (Vetecor, Lab. Calier, Spain). Artificial insemination (AI) was performed on Day 12 using frozen-thawed semen from a bull of proven fertility. Only one AI was performed per heifer/cow. Pregnancies were determined by ultrasound examination at 53 days following AI and confirmed by rectal palpation at 90 days post AI. The use of this estrus synchronization protocol, followed by fixed-time insemination, resulted in four pregnant heifers (66%) and three pregnant cows (100%). Our results demonstrate that buffalo reproduction can be successful during out-of-breeding season when adequate hormonal treatment is used. Additional experiments should be done to validate the protocol.

10 INFLUENCE OF ADMINISTRATION OF HUMAN CHORIONIC GONADOTROPIN ON DAY 4 AFTER FIXED-TIME AI ON CORPUS LUTEUM SIZE, FUNCTION, AND PREGNANCY RATE IN BEEF COWS

2014 ◽  
Vol 26 (1) ◽  
pp. 119
Author(s):  
J. B. S. Borges ◽  
D. X. Thedy
Keyword(s):  
Corpus Luteum ◽  
Pregnancy Rate ◽  
Fixed Time ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Control Group ◽  
Chi Square ◽  
Prostaglandin F2a ◽  
Successful Establishment ◽  
Early Rise

Successful establishment of pregnancy in the cow depends on early rise of progesterone (P4) to improve embryo development. The present study was carried out to determine the corpus luteum (CL) function and pregnancy rate following the administration of 1.500 IU of hCG in suckled beef cows on Day 4 after fixed-time AI (FTAI). Crossbred Angus cows (n = 429), 40 to 70 days postpartum, were synchronized using 2 mg of oestradiol benzoate (EB) i.m. and an intravaginal progesterone-releasing device containing 1 g of P4 for 7 days. At device removal, prostaglandin F2a (150 mg of D-cloprostenol) was injected i.m.; 24 h later, 1 mg of EB was given and the FTAI were done 30 to 36 h after EB using semen of just 1 bull. Cows were assigned alternatively to receive 1.500 IU of hCG i.m. (n = 200) or 1 mL of saline i.m. (n = 229) on Day 4 after FTAI. Ovaries were examined by transrectal ultrasonography (n = 71) on Days 4 and 7 to detect the presence and to measure the area of CL. Blood samples were collected on Days 4, 7, 10, 14, and 30 post-oestrus to determine P4 concentration by RIA. Pregnancy diagnoses were done 30 days after FTAI. The effects of treatments on CL area and serum P4 levels were analysed by ANOVA (Proc GLM, SAS Institute Inc., Cary, NC, USA) and pregnancy rates compared by chi-square (Proc CATMOT, SAS). The induction of accessory CL determined on Day 7 was 44% in cows treated with hCG and not observed in the control group. The area of the CL on Day 7 was significantly higher (P < 0.01; 3.37 ± 2.56 v. 2.56 ± 0.22 cm2) in the hCG group. Despite the increase in CL size, the mean levels of P4 on Days 4, 7, 10, 14, and 30 post-AI indicated no difference (P > 0.05) in CL function between control and hCG-treated cows. On Day 30, pregnancy rates were not different (P = 0.08), at 46.7 and 55% for control and hCG-treated cows, respectively. In conclusion, administration of 1.500 IU of hCG on Day 4 post-FTAI did not improve pregnancy rate in suckled beef cows.

8 EFFECT OF SEMEN TYPES (SEXED v. NONSEXED) ON CONCEPTION RATES OF GIROLANDO HEIFERS INSEMINATED IN FIXED-TIME AI

2010 ◽  
Vol 22 (1) ◽  
pp. 162
Author(s):  
J. Almeida ◽  
O. A. Resende ◽  
D. L. Silveira
Keyword(s):  
Body Condition Score ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Sao Paulo ◽  
São Paulo ◽  
Device Removal ◽  
Conception Rates ◽  
Sexed Semen ◽  
Condition Score ◽  
Intravaginal Device

With the goal of optimizing protocols, fixed-time artificial insemination (FTAI) was performed under field conditions in a study to evaluate conception rates in Girolando (5/8) heifers (18 to 24 months of age) treated with estradiol benzoate (BE) to induce ovulation. Forty heifers were allocated to 2 groups with 20 animals each: GI-sexed semen (2 million spermatozoa/dose) and GII-nonsexed semen (20 million spermatozoa/dose), with body condition score (BCS) of 3.0 ± 0.14 (scale of 1 to 5), middleweight of 335 ± 38 kg, so that it was made for reutilization of progesterone device. On Day 0 (morning), the animals received 2.0 mg of BE (RIC-BE®,Tecnopec, São Paulo, Brazil), 0.075 mg of D-cloprostenol (Prolise®, ARSA S.R.L., Buenos Aires, Argentina), and an intravaginal device of 1 g of progesterone (Primer®, Tecnopec). On Day 8 (morning) the device was removed and 0.075 mg of D-cloprostenol was managed in the GI animals, then these animals received 1.0 mg of BE 24 h after device removal. The insemination was in the late afternoon of Day 10 with a 6-hour delay (4 to 6 pm). The GII animals received Primer previously used for 8 days (being used in the GI animals under the same protocol). After pregnancy diagnosis at 60 days, a third group was created (GIII) using the not-pregnant animals of GI and GII. In GIII, Primer from third use [disinfected in solution Kilol®-L 1:250 (Quinabra, São Paulo, Brazil) and rinsed with water, dried, and packed in plastic sacks and kept for 60 days] was used following the GI protocol with sexed semen. There were no significant differences (P > 0.05) in the conception rates of 40, 58, and 65% among groups GI (8/20), GII (11/20), and GIII (13/20). These results indicate very good conception rates for heifers, contrary to recommendations of commercial companies of sexed semen that alert for the conception rate for mated animals to be lower when using FTAI and mating protocols in mass, compared with that of AI after estrus observation.

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