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.

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.

171 Follicular and luteal characteristics and pregnancy rates in Bos indicus suckled cows treated with two oestradiol/progesterone-based protocols with a prolonged pro-oestrus

2020 ◽  
Vol 32 (2) ◽  
pp. 212
Author(s):  
A. Cedeño ◽  
R. Maingón ◽  
J. P. Cedeño ◽  
C. Guadalupe ◽  
L. Morales ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Body Condition Score ◽  
Bos Indicus ◽  
Fixed Time ◽  
Beef Cows ◽  
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 on follicular and luteal characteristics and pregnancy rates to fixed-time AI (P/FTAI) in Bos indicus cows treated with oestradiol/P4-based treatments with a prolonged pro-oestrus. Multiparous Bos indicus suckled beef cows (n=659), 60-90 days postpartum, with a corpus luteum (CL) or at least one follicle ≥8mm in diameter and with a body condition score between 2 and 3.5 (1-to-5 scale) were synchronised using three treatments. On Day 0, all cows 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 cows in the J-Synch 6 group (n=195) and on Day 7 in cows in the J-Synch 7 group (n=262) and conventional group (n=202). All cows received 500μg of cloprostenol (Sincrocio, Ourofino) and 400IU of equine chorionic gonadotrophin (SincroeCG 6000UI, Ourofino) at the time of P4 device removal. Cows in the conventional treatment group also received 0.5mg of oestradiol cypionate (SincroCP, Ourofino) at the same time. In addition, all cows were tail-painted for oestrous detection (CeloTest, Biotay). Cows that had lost ≥50% of the tail paint 62-66h (J-Synch groups) or 48-52h (conventional group) after device removal were FTAI at that time. Cows not showing oestrus by 62-66h (J-Synch groups) or 48-52h (conventional group) received 10μg of GnRH (Sincroforte, Ourofino) at the same time and were FTAI 8h later. A subset of 20 cows per group was 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 CL diameter, and 30 days after FTAI to determine P/AI. Data were analysed using the GLM Mixed procedure (InfoStat). The results are shown in Table 1. The diameter of the dominant preovulatory follicle was larger and the interval from device removal to ovulation was longer in cows in the J-Synch groups compared with those in the conventional group (P&lt;0.05). Furthermore, the diameter of the CL was larger and P/FTAI was higher in cows in the J-Synch 7 group compared with those in the J-Synch 6 and conventional groups. In conclusion, delaying the removal of the P4 device by 1 day (i.e. Day 7 vs. Day 6) in the J-Synch groups and prolonging the pro-oestrus period by not giving oestradiol cypionate at P4 device removal (i.e. J-Synch 7 vs. conventional) resulted in a larger preovulatory follicle and CL and higher P/FTAI in Bos indicus suckled cows. 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 fixed-time AI (P/FTAI) in Bos indicus suckled cows Treatment P/Foll diameter, mm CL diameter, mm Interval to ovulation, h P/FTAI,% (n) J-Synch 6 15.5±0.3a 18.7±0.8a 83.0±4.0b 41.0 (80/195)a J-Synch 7 16.4±0.2b 21.9±0.8b 86.0±3.0b 52.0 (136/262)b Conventional 13.8±0.2a 16.8±0.9a 64.0±3.0a 37.1 (75/202)a a,bDifferent superscripts denote differences between means or P/FTAI.

7 Pregnancy rates in suckled beef cows synchronized with a shortened progesterone/oestradiol-based protocol (J-synch) and inseminated with conventional or sexed-sorted semen

2019 ◽  
Vol 31 (1) ◽  
pp. 129 ◽  
Author(s):  
G. A. Bo ◽  
E. E. Huguenine ◽  
J. J. de la Mata ◽  
R. L. R. de Carneiro ◽  
A. Menchaca
Keyword(s):  
Corpus Luteum ◽  
Linear Model ◽  
Body Condition ◽  
Binary Data ◽  
Body Condition Score ◽  
General Linear Model ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Oestradiol Benzoate ◽  
Condition Score

An experiment was designed to evaluate pregnancy rates (P/AI) in suckled beef cows synchronized with a progesterone (P4)/oestradiol-based protocol (J-Synch) and inseminated (AI) with sexed or nonsexed (conventional) semen. Angus or Angus crossbred cows (n=877), 60 to 90 days postpartum, with a body condition score of 2.5 to 3.5 (scale of 1 to 5) and a corpus luteum or a follicle &gt;8mm in diameter detected by ultrasonography, were randomly allocated to be AI with sexed-sorted or nonsexed (conventional) semen. The experiment was performed in 4 farms, and the sexed-sorted (SexedUltra™ 4M, with 4 million sperm; ST Genetics, Navasota, TX, USA) and conventional (25 million sperm) semen were from split ejaculates from 5 Angus bulls. All cows received a P4 device (DIB 0.5, Zoetis, Villa Adelina, Argentina) and 2mg of oestradiol benzoate (Gonadiol, Zoetis) on Day 0. On Day 6, cows received 400IU of eCG (Novormon 5000, Zoetis) and 500µg of cloprostenol (Ciclase DL, Zoetis) and DIB was removed. All cows were also tail painted and observed for signs of oestrus (i.e. &gt;30% of the tail paint rubbed off) at 60, 72, and 84h after DIB removal. Cows with the tail paint rubbed off by 60 or 72h after DIB removal were artificially inseminated at 72h with either sexed or conventional semen. Those not showing oestrus by 72h received 100µg of gonadorelin acetate (Gonasyn GDR, Zoetis) at that time and were artificially inseminated with either sexed-sorted or conventional semen 12h later (i.e. 84h). Pregnancy was diagnosed by ultrasonography 30 days after AI. Data were analysed by general linear model for binary data with a logit link. Overall, 76.4% (678/877) of cows showed oestrus 60 to 84h after DIB removal, and there were differences in P/AI between sexed-sorted and conventional semen (P&lt;0.01; Table 1); however, there was no farm effect (range: 52-59%) and no interactions. Fertility differed (P&lt;0.05) among bulls and ranged from 25.8 to 55.3% for sexed-sorted semen and from 53.1 to 73.9% for conventional semen. In cows artificially inseminated with sexed-sorted semen, P/AI was the highest in cows showing oestrus and AI at 84 h; however, no differences were detected among cows artificially inseminated with conventional semen (Table 1). Although P/AI was lower for sexed-sorted than conventional semen, tail painting for oestrus detection can be successfully applied to AI beef cows with sexed-sorted semen synchronized with a shortened P4/oestradiol-based protocol. Table 1.Effect of semen type (sexed-sorted or conventional) and time of oestrus and AI on P/AI in suckled beef cows synchronized with a shortened P4/oestradiol-based protocol Research was supported by Fondo Nacional de Ciencia y Tecnología (FONCYT PICT 2017-4550) and UNVM.

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

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.

scholarly journals 9THE USE OF ECG TO INCREASE PREGNANCY RATES IN POSTPARTUM BEEF COWS FOLLOWING TREATMENT WITH PROGESTERONE VAGINAL DEVICES AND ESTRADIOL BENZOATE AND FIXED-TIME AI

2004 ◽  
Vol 16 (2) ◽  
pp. 127 ◽  
Author(s):  
G.A Bo ◽  
L. Cutaia ◽  
P. Chesta ◽  
D. Moreno
Keyword(s):  
Body Condition Score ◽  
Fixed Time ◽  
Beef Cows ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Control Group ◽  
Treatment Groups ◽  
Condition Score ◽  
N 93 ◽  
Rectal Palpation

Treatments with progesterone (P4) releasing devices and estradiol benzoate (EB) have been extensively used in fixed-time AI (FTAI) programs in beef cattle. However, pregnancy rates in postpartum cows kept on pasture often have been lower than expected because of poor body condition score (BCS) and a high incidence of anestrous. A recent study (Cutaia L et al., 2003 Theriogenology 59, 216) suggested that the addition of eCG to a P4/EB FTAI program may improve pregnancy rates in cows with fair to poor BCS, but results were not conclusive. Therefore, this experiment was designed to further investigate the effect of eCG treatment on pregnancy rates in postpartum beef cows in those conditions. The experiment was performed at 2 locations with lactating Angus cows (n=93), 60 to 90d postpartum with a BCS 1.9 (1 to 5 scale; Location 1), and crossbred Zebu cows (n=290), 60 to 90d postpartum with a BCS 2.0 (Location 2). In each Location, cows were randomly allocated to 1 of the following treatment groups: Control, eCG Day6, or eCG Day8. All cows received a P4 intravaginal device (DIB, Syntex, Argentina) and 2mg EB i.m. (Syntex) on Day0, 500mg cloprostenol (Estroplan, Syntex) at the time of DIB removal (Day8), 1mg EB i.m. on Day9 and FTAI 52 to 56h after DIB removal. Cows in the Control group received no further treatment, whereas cows in the eCG-treated groups received 400 IU eCG (Novormon 5000, Syntex) on Day6 or Day8. Cows were examined on Day0 by rectal palpation (Location 1) or by ultrasonography (US; Location 2) and were classified as those with a CL or without a CL, with either large (&gt;8mm) or small (&lt;8mm)small follicles. Pregnancy was determined by US 45d after FTAI. Data were analyzed by logistic regression and the effects of location, treatment, ovarian status, AI technician and semen were considered in the model. There was no effect of location (P=0.3), AI technician (P=0.2) or semen (P=0.8) on pregnancy rates. However, there was an effect of treatment (P=0.02), attributed to higher pregnancy rates in the eCG Groups than in the Control Group (Table). Furthermore, cows with a CL or without a CL but with large follicles on Day 0 had higher pregnancy rates than those with small follicles (P=0.04). It was concluded that the use of eCG in a P4/EB FTAI program improved pregnancy rates in postpartum beef cows that were in fair topoor BCS.

12 THE EFFECT OF PROGESTERONE CONTENT IN A VAGINAL INSERT ON PREGNANCY RATES IN BEEF AND DAIRY CATTLE INSEMINATED AT FIXED TIME

2006 ◽  
Vol 18 (2) ◽  
pp. 114
Author(s):  
L. Cutaia ◽  
M. Aviles ◽  
F. Feresin ◽  
A. Franzoni ◽  
L. Peres ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Body Condition Score ◽  
Fixed Time ◽  
Beef Cows ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Holstein Cows ◽  
Chi Square ◽  
Condition Score ◽  
Chi Square Test

Three experiments were conducted to compare pregnancy rates in cows and heifers treated with intravaginal progesterone (P4)-releasing devices impregnated with either 0.5 or 1.0 g of P4 and inseminated at a fixed time (FTAI). In Experiment 1, 102 postpartum beef cows (Hereford and Angus crossbred with Tuli, 60 to 90 d postpartum) with a body condition score (BCS) of 2.5 to 3.0 (1 to 5 scale) were used. On Day 0, all cows received 2 mg of estradiol benzoate (EB; Syntex, Argentina) i.m. and were randomly assigned to receive an intravaginal progesterone-releasing device with 0.5 g of P4 (DIB 0.5 g; Syntex) or 1.0 g of P4 (DIB 1.0 g; Syntex). On Day 7, DIB devices were removed and all cows received 150 µg D(+)cloprostenol (Ciclase; Syntex) i.m. On Day 8, all cows received 1 mg EB and were FTAI 52 to 56 h after DIB removal. In Experiment 2, 93 Holstein cows that were 90 to 110 days in milk (DIM), producing on average 5000 kg of milk per lactation and with a BCS of 2.5 to 3.0 received the same treatments as those in Experiment 1. In Experiment 3, 100 Holstein heifers, 20 to 22 months old, with a BCS of 2.5 to 3.0, also received the same treatments as those in Experiment 1. Pregnancy rates in all experiments were determined by ultrasonography 35 days after FTAI and compared by chi-square test. No differences in pregnancy rates were detected between lactating beef cows, dairy cows, or dairy heifers treated with DIB devices impregnated with 0.5 or 1.0 g of P4 (Table 1). It was concluded that vaginal P4 releasing devices impregnated with 0.5 g or 1.0 g of P4 results in comparable pregnancy rates in FTAI protocols in beef and dairy cattle. Table 1. Pregnancy rates in postpartum beef cows, Holstein cows, and Holstein heifers treated with DIB devices impregnated with 0.5 or 1.0 g of P4 and subjected to FTAI

scholarly journals 14 EFFECT OF TEMPORARY WEANING AND ECG TREATMENT ON PREGNANCY RATES IN POSTPARTUM BOS INDICUS COWS FOLLOWING TREATMENT WITH PROGESTERONE VAGINAL DEVICES AND ESTRADIOL BENZOATE

2005 ◽  
Vol 17 (2) ◽  
pp. 157
Author(s):  
L. Cutaia ◽  
E. Balla ◽  
C. Rizzi ◽  
L. Peres ◽  
G.A. Bo
Keyword(s):  
Body Condition Score ◽  
Bos Indicus ◽  
Fixed Time ◽  
Beef Cows ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Medium Size ◽  
Ovarian Activity ◽  
Condition Score ◽  
Rectal Palpation

Although treatments with progesterone (P4)-releasing devices and estradiol benzoate (EB) have been extensively used in fixed-time AI (FTAI) programs in beef cattle, pregnancy rates in postpartum Bos indicus cows kept on pasture often have been lower than expected because of poor body condition score (BCS) and a high incidence of anestrus. Temporary weaning and eCG treatment have been shown to increase pregnancy rates in suckled beef cows. Therefore, this experiment was designed to compare the effect of eCG treatment and temporary weaning on pregnancy rates in postpartum cows in fair to poor BCS. Lactating multiparous crossbred Bos indicus cows (n = 393), 60 to 90 d postpartum with a BCS 2.0 (1 to 5 scale) were randomly allocated to 1 of 4 treatment groups, in a 2 × 2 factorial design. At the beginning of the experiment (Day 0), all cows received a P4 intravaginal device (DIB, Syntex, Argentina) and 2 mg EB i.m. (Syntex). On Day 8, DIB devices were removed and all cows received 150 μg D (+) cloprostenol i.m. (Ciclase, Syntex) and were randomly divided to receive 400 IU eCG (Novormon 5000, Syntex) or no treatment at the same time. Furthermore, half of the cows in each treatment group have their calves weaned temporarily, from the time of DIB removal until the end of the FTAI, whereas the other half remained with their calves all the time. Finally, all cows received 1 mg EB i.m. on Day 9 and were FTAI 52 to 56 h after DIB removal. Cows were examined by ultrasonography 42 d after FTAI to determine pregnancy status. Data were analyzed by logistic regression and the effects of treatment and semen used were considered in the model. Ovarian activity was estimated by rectal palpation on Day 0: there were 72/393 (18.2%) cows with a CL, 140/393 (35.6%) cows with palpable medium size follicles, and 181/393 (46.1%) cows with ovaries containing no detectable structures. There was no effect of ovarian status at the time of treatment (P = 0.91) or semen (P = 0.91) on pregnancy rates. Treatment with eCG tended (P = 0.08) to increase pregnancy rates (94/192, 48.9% and 79/201, 39.3% for cows treated or not treated with eCG, respectively). However, there was no effect of weaning or eCG by weaning interaction (P = 0.98) on pregnancy rates (86/191, 45.1% and 87/202, 43.1% for cows that have their calves weaned or not weaned for 56 h, respectively). Results confirm those of previous studies that demonstrated that the use of eCG in a P4/EB/FTAI program improved pregnancy rates in postpartum Bos indicus crossbred cows that were in fair-to-poor BCS. However, no improvement in pregnancy rates was observed after temporary weaning in the present study. Research was supported by Syntex S.A., Estancia El Mangrullo S.A., and Agencia Cordoba Ciencia S.E.

8 COMBINATION OF OESTRUS DETECTION AND FIXED-TIME ARTIFICIAL INSEMINATION IN BEEF HEIFERS FOLLOWING A SHORTENED OESTRADIOL-BASED PROTOCOL THAT PROVIDES FOR A LENGTHENED PROESTRUS

2015 ◽  
Vol 27 (1) ◽  
pp. 96 ◽  
Author(s):  
J. J. de la Mata ◽  
M. Ré ◽  
G. A. Bó
Keyword(s):  
Pregnancy Rate ◽  
Body Condition Score ◽  
Fixed Time ◽  
Beef Cows ◽  
Gonadotropin Releasing Hormone ◽  
Pregnancy Rates ◽  
Group V ◽  
Releasing Hormone ◽  
Treatment Groups ◽  
Condition Score

Studies have shown that gonadotropin-releasing hormone-based protocols that reduce the period of progestin insertion and prolong the period from progestin removal to gonadotropin-releasing hormone and fixed-time AI (FTAI; named 5-day Co-Synch) results in similar or higher pregnancy rates than the conventional 7-day Co-Synch protocol in beef cows and heifers (Bridges et al. 2008 Theriogenology 69, 843–851). Similar findings have been reported following the use of an oestradiol-based protocol that also provides for a longer period of proestrus (named J-Synch; de la Mata and Bó 2012 Taurus 55, 17–23). An experiment was designed to compare the J-Synch protocol for synchronization of ovulation that allows for a prolonged proestrus with a conventional 7-day oestradiol-based protocol for FTAI in heifers. Cycling 18-month old Angus and Hereford heifers (n = 208) with a body condition score of 6 to 7 (scale of 1 to 9) were randomly allocated to 1 of 2 treatment groups. Heifers in the 7-day EB group (n = 105) received a progesterone (P4) device (DIB 0.5 g of P4, Syntex SA, Buenos Aires, Argentina) and 2 mg of oestradiol benzoate (EB, Syntex SA) on Day 0 and 500 μg of cloprostenol (PGF; Ciclase DL, Syntex SA) and 0.5 mg oestradiol cypionate (Cipiosyn, Syntex SA) on the day of DIB removal (Day 7). Heifers were also tail painted at the time of DIB removal and observed for signs of oestrus (i.e. tail paint rubbed off). Those with the tail paint rubbed off by 36 h after DIB removal were inseminated 12 h later, whereas those not showing oestrus by 36 h were FTAI at 54 h. Heifers in the J-Synch group (n = 103) received DIB and 2 mg of EB on Day 0 and PGF on the day of DIB removal (Day 6). Heifers in this group were also tail painted at DIB removal, and those with their tail paint rubbed off by 48 h were inseminated 12 h later; those not showing oestrus by 60 h received 100 μg of gonadorelin acetate (gonadotropin-releasing hormone, Gonasyn gdr, Syntex SA) and were FTAI at 72 h after DIB removal. Pregnancy was diagnosed by ultrasonography at 55 days after FTAI (Honda 101V, 5.0-MHz transducer). Data were analysed by logistic regression. Oestrus detection rate and pregnancy rate to FTAI did not differ (P > 0.1) between groups (38.8%, 40/103 and 60.3%, 38/ 63 for heifers in the J-Synch group v. 28.5%, 30/105 and 45.3%, 34/75 for those in the 7-day EB group). However, pregnancy rates to observed oestrus tended (P < 0.09) to be higher and the overall pregnancy rate was significantly higher (P < 0.01) in heifers in the J-Synch group (80.0%, 32/40 and 67.9%, 70 /103) compared with those in 7-day EB group (50%, 15/30 and 46.6%, 49/105). Furthermore, heifers within the J-Synch group that had their tail paint rubbed off by 48 h after DIB removal and were AI 12 h later (i.e. 60 h) had higher (P < 0.05) pregnancy rate than those in the same group that were FTAI. In conclusion, reducing the time of progestin device insertion and lengthening the proestrus period, as in the J-Synch protocol, results in higher pregnancy rates than with the conventional oestradiol-based protocol. Furthermore, the combination of oestrus detection and FTAI would appear to improve the pregnancy outcome even more.

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