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.

178 USE OF A NEW INTRAVAGINAL DEVICE TO RELEASE PROGESTERONE IN FIXED-TIME EMBRYO TRANSFER EMBRYO RECIPIENTS

2010 ◽  
Vol 22 (1) ◽  
pp. 247
Author(s):  
J. R. V. Pimentel ◽  
P. H. P. Miguez ◽  
A. Kehrle ◽  
E. H. Madureira ◽  
F. A. Braga ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Body Condition Score ◽  
Block Design ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Sao Paulo ◽  
P Value ◽  
São Paulo ◽  
Condition Score ◽  
Intravaginal Device

Progestagen-releasing devices are commonly used for fixed-time artificial insemination and fixed-time embryo transfer (FTET). The aim of this study was to evaluate the efficacy of a new progesterone-releasing intravaginal device made of poly(3-hydroxy)butyrate-valerate copolymer (PHB-V) and poly-ϵ-caprolactone (PCL; Progestar®, Innovare, São Paulo, Brazil) to synchronize crossbredcows and heifers for FTET by determining ovulation, conception, and pregnancy rates. A total of 205 recipients ranging in age from 2 to 8 years (heifers, n = 77; non-suckled cows, n = 69; suckled cows, n = 59) were used on 3 different farms during February, March, and April 2008. The experimental design was a generalized block design (cyclicity, body condition score, postpartum interval, and animal category, i.e. heifers, suckled, or non-suckled cows), with 2 different synchronization treatments for FTET (Progestar® v. Crestar®). Cows were assigned to either Crestar® (norgestomet ear implants; Intervet Schering-Plough, Kenilworth, NJ, USA; n = 103) or Progestar® (PHB-V; n = 102) treatments. All groups were treated with 2 mg of estradiol benzoate i.m. (Innovare) and received the intravaginal or auricular device according to their group (Day 0). Together with P4 device withdrawal (Day 8), all animals received 400 IU of eCG i.m. (Novormon®, Schering-Plough) and 500 μg i.m. of PGF2α, (Sincrocio®, Ouro Fino, Brasil). On Day 9, all cows were treated with 1 mg of estradiol benzoate (Innovare) and the innovulation was performed on Day 17. Embryos were maintained at 37°C during the innovulation period. The percentage of usable recipients (AR) based on the presence of a functional CL on the day of embryo transfer, conception rate (numbers of pregnant recipients of the total number transferred; CR), and pregnancy rate (numbers of pregnant recipients of the total number synchronized; PR) were determined by ultrasonography 23 days after embryo transfer. Data were submitted to ANOVA (PROC GLM, SAS Institute Inc., Cary, NC, USA) and significant differences were considered to have a P-value of <0.05. None of the interactions were significant and there was no effect of treatment on AR (72.8% v. 83.3%), CR (47.9% v. 42.7%), and PR (34.7% v. 35.0%) for Progestar® v. Crestar® groups, respectively. This experiment showed that Progestar® was as efficacious as Crestar® to synchronize crossbred cows and heifers for FTET. FAPESP-Fundação de Amparo à Pesquisa do Estado de São Paulo and CNPq-Conselho Nacional de Desenvolvimento Científico e Tecnológico.

scholarly journals Development of fixed-time artificial insemination protocols for locally adapted Curraleiro Pé-Duro cows

2016 ◽  
Vol 68 (5) ◽  
pp. 1159-1167 ◽  
Author(s):  
R.D. Tortorella ◽  
M.R. Modesto ◽  
J.P. Neves ◽  
A.F. Ramos
Keyword(s):  
Body Condition Score ◽  
Hormonal Treatment ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Device Removal ◽  
Condition Score ◽  
Equine Chorionic Gonadotropin ◽  
Hot Environments ◽  
To Receive ◽  
Intravaginal Device

ABSTRACT Two experiments were conducted aiming to evaluate the effects of two ovulatory inducers (Exp.1) and equine chorionic gonadotropin (eCG; Exp.2) on follicular and luteal dynamics in a fixed-time AI (FTAI) protocol in locally adapted Curraleiro Pé-Duro cows. In Exp. 1 multiparous cows (n=12) received an intravaginal device containing 1g of progesterone (P4) for 8 days and 2mg of estradiol benzoate (EB) intramuscularly (IM) at device insertion (Day 0). At device removal (Day 8) 0.150mg of Sodium D-Cloprostenol was administered IM and the cows were randomly assigned to receive 1mg of EB (EB8) or 1mg of estradiol cypionate (EC8) IM, or to not receive any ovulatory inducer (Control). All the animals participated in all treatments (crossover). The interval from P4 removal to ovulation was shorter and less variable in the EB8 treatment group (P≤0.05). In Exp. 2 (crossover), multiparous cows (n=12) received the same hormonal treatment as the EB8 group in Exp.1. At device removal (Day 8) cows were randomly assigned to receive 300UI of eCG IM or to not receive eCG (Control). No difference was ascertained on follicular and luteal parameters in Exp. 2 (P>0.05). We concluded that EB can be used as the ovulatory inducer (Exp. 1) in a FTAI protocol in Curraleiro Pé-Duro cows. However, eCG (Exp. 2) was not able to stimulate follicular and luteal development. This result is probably due to the adaptive capacity of Curraleiro Pé-Duro cows that maintained a satisfactory body condition score even in dry and hot environments.

7 ARTIFICIAL INSEMINATION IN BOS INDICUS WITH SEMEN IN SIMULTANEOUS POOL OF MULTIPLE BULLS

2010 ◽  
Vol 22 (1) ◽  
pp. 161
Author(s):  
J. R. S. Torres-Júnior ◽  
J. A. T. Souza ◽  
M. I. S. Silva ◽  
J. S. Costa ◽  
G. S. Lima ◽  
...  
Keyword(s):  
Body Condition Score ◽  
Bos Indicus ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Sao Paulo ◽  
Conception Rate ◽  
São Paulo ◽  
Conventional Dose ◽  
Conception Rates ◽  
Time Required

The duration of spermatic viability in the female reproductive system in cattle is 18 to 24 hours. Therefore, the time required for sperm capacitation in different bulls demonstrated to be highly variable and may affect the adequate amount of capacitated sperm within an optimal window of time for fertilization. The aim of this study was to evaluate the conception rate in Nelore cows inseminated with semen from a single bull compared with semen from a pool of 3 bulls (Fertility Plus®, ABS Pecplan, Minas Gerais, Brazil). On a random day of the estrous cycle (Day 0), 400 Nelore multiparous cows received a progesterone intravaginal device (1 g of P4, DIB®, Intervet/Schering-Plough, Cotia, Brazil) plus 2mg of estradiol benzoate (i.m. Estrogin®, Farmavet, São Paulo, Brazil). At the time of P4 device withdrawal (Day 8), 150 (ig of d-cloprostenol (i.m. Preloban®, Intervet/Schering-Plough), 1 mg of estradiol cypionate (i.m. ECP®, Pfizer, Brazil), and 300IU of eCG (i.m. Folligon®, Intervet/Schering-Plough) were administered. At 48 to 52 h after implant removal, all cows were fixed-time inseminated (FTAI). Then, cows were homogeneously distributed based on the semen used for FTAI in 4 groups: CONV1 (conventional dose of semen from bull 1), CONV2 (conventional dose of semen from bull 2), CONV3 (conventional dose of semen from bull 3), FERT (pool of semen from bulls 1, 2 and 3 homogeneously mixed in a single dose). Both conventional and Fertility Plus batches of semen contained a total dose of 30 × 106 spermatozoa. For pregnancy diagnosis, an ultrasonographic (CHISON 500VET, USP Brasil Eletromedicina, São Paulo, Brazil) examination 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 body condition score [using a 1 (very thin) to 5 (very fat) point scale] or AI technician. The conception rates for CONV1, CONV2, CONV3, and FERT were, respectively, 40/101 (39.6%)b, 50/99 (50.5%)ab, 46/99 (46.5%)ab, 54/101 (53.5%)a; P < 0.05. In addition, the mean of conventional v. Fertility Plus treatments presented conception rates of 136/299 (45.5%) v. 54/101 (53.5%), respectively (P = 0.14). No significant statistical differences were observed between treatments. However, this trial showed that the utilization of the new Fertility Plus technology increased the overall conception rate by 8.0%. This probably implicates a complementary effect among semen samples and provides a greater time of sperm viability in oviduct. Also it provides evidence of the individual variation in capacitation time of bulls used for composition of the pool. Pooled semen of multiple sires may improve the reproductive performance at AI in cattle and increase the potential of the beef industry to produce pregnancies and born calves.

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.

203 EFFECT OF SUPPLEMENTAL FOLLICLE-STIMULATING HORMONE OR EQUINE CHORIONIC GONADOTROPIN DURING THE PROTOCOL FOR TIMED AI IN HIGH-PRODUCING HOLSTEIN COWS

2010 ◽  
Vol 22 (1) ◽  
pp. 260 ◽  
Author(s):  
H. Ayres ◽  
R. M. Ferreira ◽  
M. C. Wiltbank ◽  
P. S. Baruselli
Keyword(s):  
Body Condition Score ◽  
Estradiol Benzoate ◽  
Sao Paulo ◽  
Additional Treatment ◽  
Dairy Herds ◽  
São Paulo ◽  
Condition Score ◽  
Parity Number ◽  
Equine Chorionic Gonadotropin ◽  
Ovulatory Follicles

Programs that allow timed AI (TAI) have been used to improve reproductive efficiency in dairy herds; however, in many cases pregnancies per AI (P/AI) during these programs remain suboptimal. In the present experiment, it was hypothesized that treatment with FSH or eCG at the time of the PGF2 treatment of the TAI protocol would increase fertility in dairy cattle. This experiment was performed in June 2008 (winter) and January 2009 (summer) on 2 commercial dairy farms located in southeast Brazil. On a random day of the estrous cycle (Day 0), 694 cows at 196 ± 138 days in milk (DIM) received 2 mg of estradiol benzoate (RICB®, Tecnopec, São Paulo, Brazil) i.m. and a releasing intravaginal device (P4; Primer®, Tecnopec), which was removed on Day 8 when 150 μg of PGF (Prolise®, ARSA, Buenos Aires, Argentina) i.m. were administered. At this time, the cows were stratified by days in milk (DIM), parity, number of insemination, milk production, presence of a CL on Day 0, and body condition score (BCS) and were randomly assigned to 1 of 3 treatments: control (n = 232), consisting of no additional treatment; eCG (n = 232), consisting of 400 IU of eCG (Folligon®, Intervet, São Paulo, Brazil); and FSH (n = 230), consisting of 20 mg of FSH (Folltropin®, Bioniche, Belleville, Ontario, Canada). All cows received GnRH (100 μg of gonadorelin; Fertagyl®, Intervet) and were TAI 56 h after the removal of the device. Pregnancy diagnosis was performed 30 and 60 days after TAI. Also, a subset of animals (n = 89) was submitted to ultrasonographic exams to evaluate the diameter of the ovulatory follicles (ØOF), time to ovulation after P4 removal (TOV), and ovulation rate (OR). Statistical analyses were performed with logistic regression by PROC GLIMMIX of SAS (SAS Institute, Cary, NC, USA). There were no interactions of treatment with DIM, parity, number of insemination, BCS, locomotion score, sire, batch, inseminator, farm, or month; therefore, these variables were removed from the statistical model. The overall P/AI was different between treatments at 30 days after TAI [control = 28.0% (65/232), eCG = 29.7% (69/232), and FSH = 18.7% (43/230); P = 0.01], but not at 60 days [control = 21.6% (50/232), eCG = 24.1% (56/232), and FSH = 16.1% (37/230); P = 0.08]. Pregnancy loss was also similar among treatments [control = 23.1% (15/65), eCG = 18.8% (13/69), and FSH = 14.0% (6/43); P = 0.08]. In addition, the treatments (control, eCG, and FSH, respectively) were not different among ØOF (13.78 ± 0.52; 14.50 ± 0.59; and 15.35 ± 0.69 mm; P = 0.15); TOV (82.50 ± 2.14; 78.48 ± 2.35; and 78.96 ± 2.39 h after P4 withdrawal; P = 0.30); or OR [82.76% (24/29); 83.33% (25/30); and 83.33% (25/30); P = 0.44]. Thus, these data do not indicate a major fertility-enhancing effect of a single eCG or FSH treatment during protocol for TAI in high-producing dairy cows, contrary to the hypothesis of the present study. Tecnopec, Fazenda Campestre, Agrindus S/A, Echoa e Nutricell Nutrientes Celulares.

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.

175 FOLLICULAR DIAMETER AND OVULATION RATE IN NELLORE COWS TREATED WITH LH

2009 ◽  
Vol 21 (1) ◽  
pp. 186
Author(s):  
R. A. L. Simões ◽  
F. S. Rosa ◽  
M. Piagentini ◽  
R. A. Satrapa ◽  
R. L. Ereno ◽  
...  
Keyword(s):  
Buenos Aires ◽  
Preliminary Test ◽  
Estradiol Benzoate ◽  
Sao Paulo ◽  
Ovulation Rate ◽  
São Paulo ◽  
Device Removal ◽  
Exact Test ◽  
Intravaginal Device ◽  
Different Doses

The aim of the present experiment was to verify the correlation between follicular diameter and ovulation rate in Nellore cows submitted to LH treatment to add information to the limited literature about this subject. A preliminary test (experiment 1) was performed to determine the lowest dose of LH necessary to induce ovulation in follicles with diameter ≥10 mm. At a random stage of the estrous cycle (D0), Nellore cows (n = 20) received a progesterone intravaginal device (1.0 g, Primer®, Tecnopec, Sao Paulo, Brazil) and 2.5 mg of estradiol benzoate (EB, i.m., Estrogin®; Farmavet, Sao Paulo, Brazil). Eight days later (D8) PGF2α was administered (150 μg of D-cloprostenol, i.m., Prolise® ARSA S.R.L., Buenos Aires, Argentina) and the device was removed. Twenty-four hours after device removal, cows were treated with EB (1.0 mg, i.m.) and 48 h afterward; ovulation was determined by ultrasonography (US, Aloka 900, Tokyo, Japan). Three days after ovulation, the follicular growth was daily observed by US, and when the follicles reached ≥10 mm diameter, the cows were randomly allocated in 4 groups and treated with different doses of LH (i.m., Lutropin-V®, Bioniche, Ontario, Canada): Groups 1.56; 3.12; 6.25, and 12.5 mg. The data were analyzed by Fisher’s Exact Test (PROC FREQ, SAS). The ovulation rates were 0% (0/5), 80% (4/5), 80% (4/5), and 80% (4/5) respectively, and it was lower in group 1.56 when compared with the others (P < 0.02). Taking in account the results above, the dose of 6.25 mg to induce ovulation in Nellore cows (n = 58, experiment 2) submitted to the same protocol used in experiment 1 and randomly allocated in 5 groups according to follicular diameter at the time of LH administration: G1 (7.0–7.5 mm), G2 (7.6–8.0 mm), G3 (8.1–8.5 mm), G4 (8.6–9.0 mm), and G5 (9.1–10.0 mm). The results were analyzed by Logistic Regression (PROC GENMOD, SAS). The ovulation rates were 0% (0/11), 20% (2/10), 36% (4/11), 36% (4/11), and 90% (9/10), respectively, for G1, G2, G3, G4, and G5. When the data from 2 groups (except G5) were combined, G1 + G2 (7.0–8.0 mm), G3 + G4 (8.1–9.0 mm), and G5 (9.1–10.0) ovulation rates were, respectively, 9% (2/21), 36% (8/22), and 90% (9/10). There were significant differences when comparing G1 + G2 v. G5 (P < 0.01), G3 + G4 v. G5 (P < 0.02) and G1 + G2 v. G3 + G4 (P < 0.03). After LH application, the smallest follicle that ovulated had a diameter of 7.65 mm. In summary, although LH administration induced ovulation in one follicle of 7.65 mm, high ovulation rates were observed only when the follicles reached <9.0 mm. These data will be used to study the correlation between ovulation rate and expression of isoforms of LH mRNA receptors in theca and granulosa cells. Fellowship from *FAPESP (Sao Paulo, Brazil) and **CAPES (Brasilia, Brazil).

92 INDUCTION OF FIRST POSTPARTUM OVULATION, AFTER ADMINISTRATION OF GONADOTROPIN-RELEASING HORMONE OR ESTRADIOL BENZOATE, IN NELLORE COWS

2009 ◽  
Vol 21 (1) ◽  
pp. 146
Author(s):  
V. G. Pinheiro ◽  
R. A. Satrapa ◽  
R. A. L. Simões ◽  
F. S. Rosa ◽  
C. M. Barros
Keyword(s):  
Body Condition ◽  
Body Condition Score ◽  
Hormone Treatment ◽  
Estradiol Benzoate ◽  
Sao Paulo ◽  
Gonadotropin Releasing Hormone ◽  
São Paulo ◽  
Releasing Hormone ◽  
Significant Difference ◽  
Condition Score

There are reports in the literature indicating that the presence of calf, body condition score, number of births (multiparous v. primiparous), and breed are factors that influence the duration of postpartum anestrus in beef cows. The purpose of the present study was to evaluate, during early postpartum, the time of the reestablishment of LH stocks, measured by the hypothalamic-pituitary axis responsiveness to exogenous administration of gonadotropin-releasing hormone (GnRH) or estradiol benzoate (EB). Primiparous lactating Nellore cows (n = 38, body condition score 2.5 to 3.5, on a 0 to 5 scale) were kept in a Brachiaria brizantha pasture. The animals were randomly allocated into 2 groups, according to hormone treatment: EB group (1 mg EB, i.m., Estrogin®, Farmavet, Sao Paulo, Brazil; n = 20) and GnRH group (100 μg, licerelina, i.m, Gestran Plus®, ARSA S.L.R., Buenos Aires, Argentina; n = 18). In each group, half of the animals were supplemented with a balanced diet based on cotton meal and ground corn. The drugs were administered from 7 days postpartum (±4 days), at intervals of 7 days, until the occurrence of the first ovulation that was observed by weekly ultrasonography (US, Aloka 900, Tokyo, Japan; 7.5-MHz transrectal probe). The data were analyzed by ANOVA (Proc GLM, SAS Institute, Cary, NC). Within the GnRH and EB groups, the first ovulation occurred 15 and 33 days postpartum, respectively, whereas the group averages (± SD) occurred earlier in cows treated with GnRH compared with those treated with EB (43.0 ± 3.8. v. 75.1 ± 8.7 days postpartum, respectively; P < 0.01). In the EB group, 4 animals did not ovulate until Day 140 postpartum. There was no interaction of treatment (GnRH, EB) × nutrition (supplemented, nonsupplemented). When data from the EB and GnRH groups were combined, there was a significant difference between supplemented and nonsupplemented animals (44.4 ± 6.2 v. 68.9 ± 7.3 days, respectively; P < 0.02). The results indicate that GnRH induces ovulation from Day 15 postpartum, suggesting the presence of sufficient LH in the pituitary to induce the first ovulation at this time. However, EB administration did not induce ovulation in this period, possibly because of the sensitivity of the hypothalamus to negative feedback of estrogens, inhibiting the preovulatory LH surge. These results also indicate that nutritional supplementation anticipates the first postpartum ovulation induced by GnRH or EB. Support by FAPESP(Sao Paulo, Brazil); fellowship from FAPESPA; fellowship from CAPESB.

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.

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