113 Different doses of equine chorionic gonadotrophin on pregnancy and twin rates of Bos taurus beef heifers subjected to J-Synch protocol for fixed-time artificial insemination

2021 ◽  
Vol 33 (2) ◽  
pp. 164
Author(s):  
C. G. Pintos ◽  
R. Núñez-Olivera ◽  
F. Cuadro ◽  
C. Brochado ◽  
G. A. Bó ◽  
...  
Keyword(s):  
Bos Taurus ◽  
Body Condition Score ◽  
Fixed Time ◽  
Chorionic Gonadotrophin ◽  
P Value ◽  
Device Removal ◽  
Beef Heifers ◽  
Buserelin Acetate ◽  
Condition Score ◽  
Different Doses

The objective was to evaluate the effect of different doses of equine chorionic gonadotrophin (eCG) on pregnancy (P/AI) and twin rates of beef heifers in a progesterone and oestradiol-based treatment (J-Synch protocol) for fixed-time AI (FTAI). A total of 1,404 Bos taurus beef heifers with a body condition score 4.8±0.5 (mean±s.e.m., scale 1–8) were used in three different locations. The presence of a corpus luteum (CL) was determined by ovarian ultrasonography (5.0MHz) at the beginning of the J-Synch protocol. On Day 0, the heifers received 2mg of oestradiol benzoate (intramuscular, IM) associated with an intravaginal device containing 0.5g of progesterone. At device removal, on Day 6, 500µg of cloprostenol sodium was administered IM and the females were randomly assigned to one of two experimental groups to receive 200 (n=702) or 300 (n=702) IU of eCG (Zoetis) IM. Heifers were also tail-painted. On Day 0 females with paint rubbed-off were FTAI 64 h after device removal, and those that remained with the paint received 8 μg of buserelin acetate 64 h after device removal to be FTAI 8 h later. FTAI was performed at 64 to 72h after device removal, and pregnancy diagnosis was performed by ultrasonography 30 to 35 days after insemination. Data were analysed by logistic regression using GLMM. The results are shown in Table 1. Pregnancy rate was not different between heifers treated with 200 or 300IU of eCG (P=0.513) and was not affected by the presence of CL at the beginning of the protocol (P=0.513). Twin rate was greater in heifers treated with 300IU than with 200IU of eCG (P=0.005), and it was not affected by the presence of CL (P=0.362). Interaction between eCG treatment and presence of CL was not significant for pregnancy or twin rates (P=0.532). In conclusion, although 300IU of eCG increased the twin rate compared with 200IU, no differences were found in P/AI. We suggest that the dose of eCG in the J-Synch protocol could be adjusted to 200IU in Bos taurus beef heifers. Table 1. Pregnancy per AI (P/AI) and twin rates obtained with different doses of eCG (200 or 300IU) in a J-Synch protocol for fixed-time AI in cycling (CL) and anestrous (no CL) Bos taurus beef heifers Variable 200 IU 300 IU P-value CL no CL Total CL No CL Total eCG CL eCG×CL P/AI (%) 61.6% (135/219) 59.8% (289/483) 60.4% (424/702) 60.2% (133/221) 59.5% (286/481) 59.7% (419/702) 0.513 0.513 0.513 Twin rate (%) 3.0% (4/135) 3.5% (10/289) 3.3% (14/424) 6.8% (9/133) 9.4% (27/286) 8.6% (36/419) 0.005 0.362 0.532

39 EFFECT OF TIME OF FIXED-TIME AI ON PREGNANCY RATES IN ZEBU CROSS-BRED BEEF HEIFERS TREATED WITH PROGESTERONE RELEASING DEVICES AND ESTRADIOL CYPIONATE

2010 ◽  
Vol 22 (1) ◽  
pp. 177 ◽  
Author(s):  
M. Ramos ◽  
L. Cutaia ◽  
P. Chesta ◽  
G. A. Bó
Keyword(s):  
Bos Taurus ◽  
Body Condition Score ◽  
Bos Indicus ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Beef Heifers ◽  
Treatment Groups ◽  
Condition Score ◽  
To Receive

Two experiments were designed to evaluate the effect of the timing of fixed-time AI (FTAI) in relation to the removal of an intravaginal progesterone-releasing device (1 g of progesterone, DIB, Syntex SA, Buenos Aires, Argentina) on pregnancy rates in Bos indicus × Bos taurus cross-bred heifers. In experiment 1, 285 Bonsmara × zebu cross-bred heifers, between 18 and 24 months of age and with a body condition score (BCS) between 3.0 and 3.5 (1-5 scale) were used. On the day of initiation of treatment (Day 0), the heifers’ ovaries were palpated (92% of them had a CL) and they received a new DIB plus 2 mg of estradiol benzoate (EB; Syntex SA) and 250 μg of cloprostenol (Ciclase DL, Syntex SA). On Day 8, DIB devices were removed and all heifers received 250 μg of Ciclase plus 0.5 mg of estradiol cypionate (ECP; Cipiosyn, Syntex SA). At that time the heifers were randomly divided to receive FTAI between 48 to 49 h, 53 to 54 h, or 58 to 59 h after DIB removal. The heifers underwent FTAI with semen from 4 bulls by 2 inseminators. In experiment 2, 260 heifers from the same group as those used in experiment 1 (87% with a CL) were treated exactly as those in experiment 1, except that previously used DIB was inserted on Day 0. Pregnancy diagnosis was performed 30 days post-fixed-time AI by ultrasonography. The data were analyzed by logistic regression, taking into account the effect of time of FTAI, semen, and inseminator on pregnancy rates. In experiment 1, pregnancy rates were lower (P = 0.04) in the heifers undergoing FTAI between 48 and 49 h after DIB removal (46/95, 48.4%) than those undergoing FTAI 53 to 54 h (61/99, 61.6%) or 58 to 60 h (57/91, 62.6%) after DIB removal. However, no differences in pregnancy rates were found (P = 0.72) in experiment 2 between the 3 treatment groups, with 39/91 (42.9%) for the 48 to 49 h group, 45/89 (50.6%) for the 53 to 54 h group, and 35/89 (43.8%) for the 58 to 59 h group. There was no effect of the semen or inseminator (P > 0.2) in either experiment. We conclude that when Bos indicus × Bos taurus beef heifers are synchronized with new DIB devices and ECP, higher pregnancy rates are obtained in heifers undergoing FTAI late (between 53 to 60 h after DIB removal) than in those undergoing FTAI early (48 to 49 h after DIB removal). However, time of insemination does not apparently affect pregnancy rates when Bos indicus × Bos taurus beef heifers are synchronized with previously used DIB devices and ECP.

8 Evaluation of puberty induction protocol in peripubertal beef heifers prior to fixed-time AI programs

2019 ◽  
Vol 31 (1) ◽  
pp. 129
Author(s):  
J. B. S. Borges ◽  
D. S. V. Luiz ◽  
P. R. L. Aguiar ◽  
C. G. B. Berlitz ◽  
G. S. Velho ◽  
...  
Keyword(s):  
Breeding Season ◽  
Body Condition ◽  
Body Condition Score ◽  
Animal Health ◽  
Hormonal Treatment ◽  
Fixed Time ◽  
P Value ◽  
Ovarian Activity ◽  
Beef Heifers ◽  
Condition Score

Beef heifers that conceive early during their first breeding season calve earlier, wean heavier calves, and tend to continue doing so throughout the rest of their reproductive lives. Otherwise, under extensively managed systems in Southern Brazil, only a variable proportion of 2-year-old beef heifers reach puberty before the start of the breeding season. The aim of this study was to evaluate a protocol to induce puberty in peripubertal beef heifers using injectable progesterone (P4) and oestradiol cypionate (EC) to improve pregnancy per AI (P/AI) in fixed-time AI (FTAI) programs. A total of 311 Angus heifers, 24±3 months of age, 3.1±0.3 body condition score (1=emaciated; 5=obese), and 328±41kg of body weight (BW), were examined before FTAI protocol (Day −24) by transrectal ultrasonography to determine reproductive tract score (RTS; 1=prepubertal; 5=pubertal). Prepubertal heifers (RTS 1; 12.8%, 40/311) were excluded from the study. Heifers with RTS=2 (n=271) were assigned to 2 groups: P4 (RTS 2 or 3, n=100) and cyclic (RTS 4 and 5, n=171). Peripubertal heifers were treated on Day −24 with 150mg of injectable P4 IM (Sincrogest® injectable, Ourofino Animal Health, Cravinhos, Brazil) and on Day −12 received 1mg of EC IM (Sincro CP®, Ourofino Animal Health). Cyclic heifers received no hormonal treatment before FTAI protocol. On Day 0, heifers in the P4 group were evaluated again to determine RTS, body condition score, and BW. Induction of puberty was defined by the presence of a follicle >8.5mm (RTS=4) or a corpus luteum (RTS=5). All heifers received an FTAI protocol consisting of 2mg of oestradiol benzoate IM (Sincrodiol®, Ourofino Animal Health) and an intravaginal progesterone implant (1 g; Sincrogest®, Ourofino Animal Health). On Day 8, heifers had implants removed and were injected with 1mg of EC and 500µg of sodium cloprostenol IM (Sincrocio®, Ourofino Animal Health). After 48h, all heifers received an FTAI. Thirty days after AI, the diagnosis of gestation was performed by ultrasonography. Statistics included chi-square and linear regression with coefficients analysed as independent variables, considering a significant P-value of 0.05. On Day 0, percentages of RTS 5, 4, and 3 in the P4 heifers were 37, 27, and 36%, respectively, resulting in 64% of puberty induction. The P/AI was similar (P=0.14) in P4-treated and cyclic heifers (59v. 50.3%, respectively). The regression analysis presented a linear and positive effect of BW on P/AI (P<0.001) in cyclic heifers and a positive influence of BW on RTS (P=0.05) and RTS on P/AI (P=0.008) in P4-treated heifers. The application of RTS system associated with P4 treatment of peripubertal heifers before FTAI protocol improved ovarian activity and might have contributed to higher P/AI, comparable with that achieved in cyclic heifers.

173 Pregnancy rates in suckled beef cows synchronised with progesterone/oestradiol-based protocol and inseminated with conventional or sexed-sorted semen

2020 ◽  
Vol 32 (2) ◽  
pp. 214
Author(s):  
E. Huguenine ◽  
J. de la Mata ◽  
A. Menchaca ◽  
R. L. R. de Carneiro ◽  
G. A. Bo
Keyword(s):  
Binary Data ◽  
Body Condition Score ◽  
Fixed Time ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Chorionic Gonadotrophin ◽  
Device Removal ◽  
Total N ◽  
Oestradiol Benzoate ◽  
Condition Score

An experiment was designed to evaluate pregnancy rates per AI (P/AI) in suckled beef cows synchronised with a progesterone (P4)/oestradiol-based protocol and AI with non-sexed (conventional) semen and with a sexed-sorted semen with 65% X-bearing sperm and 35% Y-bearing sperm that was named SuperConventionalTM. Angus and Hereford suckled cows (n=558), 60-90 days postpartum, with a body condition score of 2 to 3.5 (1-to-5 scale) and 48% (269/558) with a corpus luteum, were randomly allocated to be AI with non-sexed (conventional) or SuperConventional semen. The experiment was performed on 3 farms using straws with sexed-sorted SuperConventional semen containing 6 or 8 million sperm and non-sorted conventional semen with 25 million sperm per straw. Semen was from split ejaculates from two Angus bulls. All cows received a P4 device with 0.6g of P4 (Pluselar, Calier) and 2mg of oestradiol benzoate (Calier) on Day 0. All P4 devices were removed on Day 8, and all cows received 400IU of equine chorionic gonadotrophin (Vetegon, Calier), 150µg of d+cloprostenol (Veteglan, Calier), and 1mg of oestradiol cipionate (Calier) at the same time. All cows were also tail-painted and observed for signs of oestrus. Cows with >30% of the tail paint rubbed off by 48-50h after P4 device removal were AI at that time with either SuperConventional or conventional semen. Those not showing oestrus by 48-50h received 10µg of buserelin (Pluserelina, Calier) at that time and were AI with either SuperConventional or conventional semen 50-52h after P4 device removal. Pregnancy was diagnosed using ultrasonography 60 days after AI, and all pregnancies were sexed to determine the proportion of female pregnancies. Data were analysed using GLM for binary data. The P/AI were different between cows showing or not showing oestrus (P<0.01) but did not differ among the three types of semen used (Table 1). The percentage of cows pregnant with female fetuses was 51% (50/98) for cows AI with conventional semen and 65.5% (55/84) and 65.3% (51/78) for those AI with SuperConventional semen with 8 million or 6 million sperm per straw, respectively. In conclusion, sexed-sorted semen with 65% of X-bearing sperm and 6 or 8 million sperm per straw can be successfully used to inseminate suckled beef cows. Furthermore, results confirm those of previous studies that cows in oestrus at the time of fixed-time AI have higher pregnancy rates than cows not in oestrus in P4/oestradiol-based synchronisation programmes. Table 1.Effect of semen type and oestrus expression on pregnancy rates per AI in suckled beef cows synchronised with a progesterone/oestradiol-based protocol Semen type In oestrus,% (n) Not in oestrus,% (n) Total,% (n) Conventional (25 million sperm) 59.8 (82/137)a 32.0 (16/50)b 52.4 (98/187) SuperConventional (8 million sperm) 53.7 (73/136)a 20.0 (10/50)b 44.6 (83/186) SuperConventional (6 million sperm) 50.4 (63/125)a 26.7 (16/60)b 42.7 (79/185) Total 54.8 (218/398)a 26.3 (42/160)b a,bDifferent superscripts denote differences in pregnancy rates per AI between cows in oestrus and not in oestrus by the time of fixed-time AI (P<0.01). Research was supported by Fondo Nacional de Ciencia y Tecnología (FONCYT PICT 2017-4550) and UNVM.

207 INFLUENCE OF THE INTERVAL BETWEEN THAWING TO TRANSFER ON PREGNANCY RATES OF FROZEN - THAWED DIRECT-TRANSFER EMBRYOS

2007 ◽  
Vol 19 (1) ◽  
pp. 220
Author(s):  
G. A. Bo ◽  
L. C. Peres ◽  
D. Pincinato ◽  
M. de la Rey ◽  
R. Tribulo
Keyword(s):  
Bos Taurus ◽  
Body Condition Score ◽  
Bos Indicus ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Direct Transfer ◽  
Condition Score ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

An experiment was designed to evaluate the effect of the interval between thawing to deposition of the embryo into the uterine horn on pregnancy rates of in vivo-produced frozen–thawed embryos in 1.5 M ethylene glycol (direct transfer). Data were collected from 1122 embryo transfers performed in the same farm (Estancia El Mangrullo, Lavalle, Santiago del Estero, Argentina) during the spring and summer of 2004/05 and 2005/06 (6 replicates, ambient temperature between 20 and 40�C). Recipients used in all replicates were non-lactating, cycling, multiparous Bos taurus � Bos indicus crossbred cows with body condition score between 3 and 4 (1 to 5 scale) that were synchronized using fixed-time embryo transfer protocols. Briefly, the synchronization treatments consisted of the insertion of a Crestar ear implant (Intervet, Sao Paulo, Brazil) or a progesterone-releasing device (DIB; Syntex SA, Buenos Aires, Argentina), plus 2 mg of estradiol benzoate (EB; Syntex) intramuscularly (IM) on Day 0, and 400 IU of eCG (Folligon 5000; Intervet, or Novormon 5000; Syntex) IM plus 150 �g d-cloprostenol IM (Preloban; Intervet, or Ciclase; Syntex) on Day 5. Progestin devices were removed on Day 8 and all cows received 1 mg of EB IM on Day 9. All cows were examined by ultrasonography on Day 16 and those with a luteal area >76 mm2 (by calculating the area of the CL minus the area of the cavity) received, on Day 17, frozen–thawed embryos by nonsurgical transfer. All embryos were Grade 1, and all were frozen in 1.5 M ethylene glycol at the Embryo Plus Laboratory (Brits, South Africa). After being stored in liquid nitrogen, the embryos were plunged directly (no air thawing) in a 30�C water bath for 30 s, and then transferred to the recipient cows by either one of two technicians. Based on the interval between thawing and transfer, the transfers were classified as being in one of 3 groups: Group 1: <3 min; Group 2: 3 to 6 min; and Group 3: 6 to 16 min. The main reason for delayed transfers beyond 6 min was the replacement of one recipient for another because of difficulty in threading the cervix (1% of the total transfers) or a recipient falling down into the chute or with very bad disposition and behavior. Pregnancy was determined by ultrasonography 28 to 35 days after fixed-time embryo transfer, and data were analyzed by logistic regression. There were no effects of replicate, technician, CL area, recipient body condition score, embryo stage, and time from thawing to transfer on pregnancy rates. Pregnancy rates in the 3 thawing to transfer intervals were: Group 1: 215/385, 55.8%; Group 2: 372/655, 56.8%; Group 3: 42/82, 51.2%; P > 0.6. These results may be interpreted to suggest that there is no significant effect of time from thawing to transfer (up to 16 min) in direct transfer embryos using Bos taurus � Bos indicus recipients transferred at a fixed time.

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.

147 Simplification of the follicle-stimulating hormone protocol for superovulation of the first follicular wave in sheep

2021 ◽  
Vol 33 (2) ◽  
pp. 181
Author(s):  
C. Brochado ◽  
B. J. Duran ◽  
J. C. L. Motta ◽  
J. D. Kieffer ◽  
A. Pinczak ◽  
...  
Keyword(s):  
Dose Group ◽  
Body Condition Score ◽  
Ovarian Response ◽  
Chorionic Gonadotrophin ◽  
P Value ◽  
Corpora Lutea ◽  
Embryo Production ◽  
Follicular Wave ◽  
Condition Score ◽  
Dose Number

The objective of the present study was to evaluate the effect of length of the FSH superstimulatory treatment on ovarian response and embryo production in sheep. Poll Dorset ewes (n=63) 3.2±0.2 years old weighing 58.5±1.5kg and with a body condition score of 2.7±0.1 (0=emaciated; 5=obese) were used during the transition from the breeding to the non-breeding season. All ewes received an ovarian superstimulatory treatment during the first follicular wave (Day 0 protocol). On Day −9 all ewes received a 0.3-g progesterone intravaginal device (CIDR, Zoetis) for 6 days. On Day −3, the CIDR was removed and all ewes were administered 125μg of cloprostenol sodium intramuscularly (IM) (PGF, estroPLAN, Parnell) and 200IU of equine chorionic gonadotrophin (eCG)+100IU of human chorionic gonadotrophin (hCG) IM (P.G. 600, Merck). Thirty-six hours after CIDR removal (Day −1.5) ewes were administered 100μg of gonadorelin acetate IM (gonadotrophin-releasing hormone, GnRH; Gonabreed, Parnell). Superstimulatory treatments were initiated on Day 0 (84 h after CIDR removal) with a total of 240mg of NIH-FSH-P1 (12 mL, Folltropin, Vetoquinol), and a new CIDR was used from the first to the last FSH dose (6-dose=3 days; 8-dose=4 days). Ewes were randomised to receive the total dose of FSH distributed in eight decreasing doses (8-dose group, n=33) or six decreasing doses (6-dose group, n=30) twice daily 12h apart. Two doses of PGF were administered with the last two doses of FSH, and GnRH was administered 12h after the last FSH administration. Intrauterine AI with fresh semen was performed by laparoscopy 16h after GnRH administration. Ovarian response was determined by laparoscopy 6 days after AI and ova/embryos were collected surgically in ewes with &gt;2 corpora lutea (CL). Data were analysed using generalized linear mixed models (SAS 9.4; SAS Institute Inc.) and presented as mean±s.e.m. in Table 1. The percentage of responding donors (&gt;2 CL) was 93.3% (28/30) and 78.8% (26/33; P=0.5) for the 6-dose and 8-dose groups, respectively. The number of CL tended (P=0.06) to be lesser in ewes in the 6-dose than the 8-dose group. However, no differences (P&gt;0.10) were found in total ova/embryo, fertilized ova, transferable embryos, or freezable embryos. In conclusion, despite a tendency for a greater ovarian response in ewes treated with 8 doses of FSH, embryo yield did not appear to differ after either 6 or 8 doses of FSH administered during the first follicular wave in sheep. Table 1. Ovulatory response and embryo production in responding ewes (&gt;2 corpora lutea) superstimulated with either 6 or 8 doses of FSH during the first follicular wave Outcome Treatment P-value 6-dose 8-dose Number of ewes 28 26 Corpora lutea (n) 14.2±1.7 20.3±2.8 0.06 Total ova/embryos (n) 9.0±1.3 10.9±1.8 0.38 Fertilized ova (n) 8.1±1.4 10.2±1.9 0.34 Fertilized ova (% per ewe) 89.0±5.0 81.7±7.0 0.40 Degenerate embryos 1.3±0.4 2.0±0.8 0.89 Transferable embryos (Grade 1–3) 6.8±1.2 8.2±1.8 0.52 Transferable embryos (% per ewe) 85.7±4.4 75.4±8.4 0.46 Freezable embryos (Grade 1–2) 6.6±1.1 8.2±1.8 0.43 Freezable embryos (% per ewe) 80.5±5.6 75.4±8.4 0.61

7 INFLUENCE OF ESTRUS EXPRESSION AND TREATMENT WITH GnRH ON PREGNANCY RATES IN BEEF CATTLE SYNCHRONIZED WITH PROGESTERONE DEVICES AND ESTRADIOL AND INSEMINATED AT A FIXED-TIME

2017 ◽  
Vol 29 (1) ◽  
pp. 111 ◽  
Author(s):  
G. A. Bó ◽  
A. Cedeño ◽  
A. Tribulo ◽  
S. Andrada ◽  
R. Tribulo ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Beef Cattle ◽  
Body Condition Score ◽  
Fixed Time ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Device Removal ◽  
Oestradiol Benzoate ◽  
Condition Score ◽  
To Receive

We have previously shown that expression of oestrus significantly influences the time of ovulation and pregnancy rates to timed-AI (P/TAI) in beef cattle synchronized with progesterone devices and oestradiol (Bó et al. 2016 Theriogenology 86, 388–396). Furthermore, delaying TAI from 48 h to 54–58 h after device removal improved P/TAI of those animals not showing oestrus by 48 h. The objective of the present study was to determine whether the administration of GnRH to those animals not showing oestrus by 48 h after device removal had an impact on P/TAI. Non-lactating and suckled beef cows and heifers (Bonsmara, Brangus, and Braford; n = 868), with a corpus luteum (CL) or a follicle ≥8 mm in diameter detected by ultrasonography (Mindray DP 30 Vet, 7.5 MHz, China) and body condition score 2 to 4 (1 to 5 scale) were synchronized in 3 replicates. On Day 0, animals received a progesterone device (DIB 0.5 g, Zoetis, Argentina) and 2 mg of oestradiol benzoate (Von Franken, Argentina). On Day 8, DIB were removed and cows received 0.150 mg of D+cloprostenol (Río de Janeiro, Argentina) plus 0.5 mg oestradiol cypionate (Cipiosyn, Zoetis). In addition, all cows were tail-painted on the sacrococcygeal area (CeloTest, Biotay, Argentina) at DIB removal and were observed to determine the expression of oestrus, according to the percentage of paint loss (PL) 48 h later. The animals that showed oestrus (PL > 30%) were recorded and TAI at that time while those with PL ≤ 30% (not in oestrus) were randomly allocated to receive 100 μg of gonadorelin (GnRH; Gonasyn, Zoetis) or no treatment and TAI between 54 to 58 h after DIB removal. Pregnancy was diagnosed by ultrasonography at 45 days after TAI, and data were analysed by logistic regression. There were no significant differences among replicates, inseminators, semen source or animal class (dry cows, suckled cows or heifers; P > 0.11). However, animals showing oestrus by 48 h after DIB removal had higher P/TAI (371/666; 55.7; P < 0.04) than those that did not show oestrus (96/202; 47.5%). Within animals not showing oestrus at 48 h, those that were in oestrus by the TAI at 54 to 58 h had higher P/TAI (71/124, 57.3%; P < 0.01) than those that did not show oestrus within that period (27/78; 34.6%). In addition, P/TAI was higher (P < 0.01) in animals that received GnRH (66/113; 58.4%) than in those that did not receive GnRH (30/89; 33.7%). In conclusion, the expression of oestrus significantly affected P/TAI in beef cattle synchronized with progesterone devices and oestradiol. Furthermore, treatment of animals not showing oestrus by 48 h after DIB removal with GnRH resulted in improved P/TAI performed 6 to 10 h later.

172 Effect of period of insertion of a progesterone-releasing device and pro-oestrus length on follicular and luteal characteristics and pregnancy rates to fixed-time AI in Bos indicus heifers

2020 ◽  
Vol 32 (2) ◽  
pp. 213
Author(s):  
G. A. Bo ◽  
A. Cedeño ◽  
R. Maingón ◽  
J. P. Cedeño ◽  
H. Gamboa ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Binary Data ◽  
Body Condition Score ◽  
Bos Indicus ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Conventional Group ◽  
Preovulatory Follicle ◽  
Device Removal ◽  
Condition Score

An experiment was designed to evaluate the effect of the length of insertion of a progesterone (P4)-releasing device and the length of pro-oestrus on follicular and luteal characteristics and pregnancy rates to AI (P/AI) in Bos indicus heifers treated with oestradiol/P4-based treatments. Bos indicus beef heifers (n=374), 22-26 months of age, with a corpus luteum (CL) or at least one follicle ≥8mm in diameter and with a body condition score between 2.5 and 3.5 (1-to-5 scale) were synchronised using three treatments for fixed-time AI (FTAI). On Day 0, all heifers received 2mg of oestradiol benzoate (Sincrodiol, Ourofino) and an intravaginal device with 1g of P4 (Sincrogest, Ourofino). The P4 device was removed on Day 6 in heifers in the J-Synch 6 group (n=120) and on Day 7 in heifers in the J-Synch 7 group (n=105) and conventional group (n=165). All heifers received 500μg of cloprostenol (Sincrocio, Ourofino) and 300IU of equine chorionic gonadotrophin (SincroeCG 6000UI, Ourofino) at the time of P4 device removal. Furthermore, heifers in the conventional treatment group received 0.5mg of oestradiol cypionate (SincroCP, Ourofino) at the same time. In addition, all heifers were tail-painted for oestrus detection (CeloTest, Biotay). Heifers that had lost ≥50% of the tail paint by 70-74h (J-Synch groups) or 48-52h (conventional group) after device removal were FTAI at that time. Heifers not showing oestrus by 70-74h (J-Synch groups) or 48-52h (conventional group) received 10μg of gonadotrophin-releasing hormone (Sincroforte, Ourofino) at the same time and were FTAI 8h later. All heifers were also examined using ultrasonography (Mindray DP50 Vet) every 12h from the time of device removal to determine the time of ovulation, 6 days after ovulation to determine the diameter of the CL, and 28 days after FTAI for P/AI determination. Data were analysed using the MLGM procedure (InfoStat) for normal data families (follicular dynamics) and binary data family (P/AI). The results are shown in Table 1. The diameter of the dominant preovulatory follicle and the CL did not differ among groups (P&gt;0.12). However, the interval from device removal to ovulation was longer in heifers in the J-Synch groups than in heifers in the conventional group (P&lt;0.05). Furthermore, P/AI was not different among groups. In conclusion, although the J-Synch protocols delayed the interval from P4 device removal to ovulation, the three protocols evaluated in the present study were equally effective in Bos indicus heifers. Table 1.Mean (±s.e.m.) diameter of the preovulatory follicle (P/Foll) and corpus luteum (CL), interval from progesterone (P4) device removal to ovulation, and pregnancy rates to AI (P/AI) in Bos indicus heifers Treatment P/Foll, mm Interval to ovulation, h CL diameter, mm P/AI,% (n) J-Synch 6 10.5±0.7 101.4±2.3a 18.6±1.0 52.0 (62/120) J-Synch 7 10.6±0.7 96.0±2.2a 16.5±0.9 39.0 (41/105) Conventional 9.4±0.7 73.0±1.9b 16.8±0.9 45.0 (74/165) a,bDifferent superscripts denote differences between groups in the interval from P4 device removal to ovulation.

104 FACTORS AFFECTING PREGNANCY RATES AND EMBRYO/FETAL LOSSES IN RECIPIENTS RECEIVING IN VITRO-PRODUCED EMBRYOS BY FIXED-TIME EMBRYO TRANSFER

2017 ◽  
Vol 29 (1) ◽  
pp. 160
Author(s):  
A. Tribulo ◽  
A. Cedeño ◽  
B. Bernal ◽  
S. Andrada ◽  
J. L. Barajas ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Body Condition Score ◽  
Prostaglandin F2α ◽  
Fixed Time ◽  
Gonadotropin Releasing Hormone ◽  
Pregnancy Rates ◽  
Device Removal ◽  
Releasing Hormone ◽  
Condition Score

A retrospective analysis evaluated pregnancy rates and embryo losses with in vitro-produced embryos in a commercial embryo transfer program on 15 different beef farms. Recipients were beef cows and heifers (n = 1841) that were synchronized with 5 different protocols and transferred at a fixed-time (FTET). Recipients were examined by ultrasonography on Day 0, and those with a corpus luteum (CL) or a follicle ≥8 mm in diameter and with body condition score 2 to 4 (1 to 5 scale) were synchronized. The synchronization treatments were as follows. (T1) Recipients received an intravaginal device with 0.5 g of progesterone plus 2 mg of oestradiol benzoate on Day 0; device removal, plus 500 μg of cloprostenol (prostaglandin F2α), 400 IU of eCG, and 0.5 mg of oestradiol cypionate on Day 8; and FTET on Day 17. (T2) This treatment was similar to T1 but 1 mg of oestradiol cypionate was injected at device removal instead of 0.5 mg of oestradiol cypionate. (T3) This treatment was similar to T1 except that animals were tail-painted on Day 8 and observed on Day 10. Those with the tail-paint intact on Day 10 received 100 μg of gonadorelin (gonadotropin-releasing hormone) and all recipients were FTET on Day 17. (T4) Recipients received a progesterone device on Day 0; device removal, prostaglandin F2α, and eCG on Day 5; gonadotropin-releasing hormone on Day 8; and FTET on Day 15. (T5) Recipients received a progesterone device and 2 mg of oestradiol benzoate on Day 0; device removal, prostaglandin F2α, and eCG on Day 6; gonadotropin-releasing hormone on Day 9; and FTET on Day 16. On the day of FTET all recipients with CL ≥18 mm in diameter (G1), ≥16 and <18 mm in diameter (G2), and ≥14 mm and <16 mm in diameter (G3) received in vitro-produced fresh embryos. Pregnancy was diagnosed by ultrasonography at 30 and 60 days of gestation, and data were analysed by logistic regression. The overall proportion of recipients synchronized that were FTET was 80.8% (1487/1841), with a 30-day pregnancy rate to FTET (P/FTET) of 45.6% (678/1487) and the rate of 30- to 60-day embryo/fetal loses on the 528 recipients that were re-checked at 60 days was 12.8% (68/528). There were no significant differences in P/FTET among operators, animal category, time of the year, embryo stage, or body condition score; however, there was a significant effect of farm (P < 0.001) and CL diameter (P < 0.05), but no interaction between CL diameter and farm or treatment (P > 0.1). Recipients with G1 (443/953, 46%) and G2 (221/462, 47%) CL had higher pregnancy rates than those with G3 CL (23/71, 32%). There was a significant effect of synchronization treatment on the proportion of recipients transferred and on P/FTET (P < 0.01) that was highly influenced by farm (farm by treatment interaction P < 0.01). The proportions of recipients selected for embryo transfer were as follows: T1: 386/486, 79.4%; T2: 233/331, 70.3%; T3: 342/377, 90.7%; T4: 126/160, 78.7%; and T5: 400/487, 82.1%. The P/FTET were as follows: T1: 190/386, 49.2%; T2: 96/233, 41.2%; T3: 175/342, 51.1%; T4: 49/126, 38.8%; and T5: 168/400, 42.0%. Although 30- to 60-day embryo/fetal losses were not influenced by synchronization treatments, they were highly influenced by farm (P < 0.001) and ranged from 0 to 34.5%. In conclusion, P/FTET in a commercial program with beef in vitro-produced embryos was influenced by factors related to the recipient (CL diameter) and the environment (farm), whereas embryo/fetal losses were influenced by farm but not treatment or recipient factors.

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