362 EFFECT OF TIME OF REMOVAL OF A PROGESTERONE RELEASING DEVICE AND GnRH TREATMENT ON THE INTERVAL TO AND DISTRIBUTION OF OVULATIONS IN SUPERSTIMULATED BEEF COWS

2006 ◽  
Vol 18 (2) ◽  
pp. 288 ◽  
Author(s):  
P. Chesta ◽  
D. Maraña ◽  
L. Peres ◽  
G. A. Bo
Keyword(s):  
Body Condition Score ◽  
Animal Health ◽  
Fixed Time ◽  
Beef Cows ◽  
Unequal Variances ◽  
Treatment Groups ◽  
Condition Score ◽  
Red Angus ◽  
To Receive ◽  
Mean Time

An experiment was designed to evaluate the effect of the time of removal of an intravaginal progesterone (P4) releasing device and GnRH treatment on the interval to and the distribution of ovulations in beef cows superstimulated with Folltropin-V (Bioniche Animal Health, Belleville, Ontario, Canada). Red Angus donors (22 cows and 12 heifers) with a body condition score between 2.5 to 3.5 out of 5 were blocked by parity and randomly assigned to one of four treatment groups in a 2 × 2 factorial design. On Day 0, all donors received an i.m. DIB vaginal device (Syntex, Argentina) plus 2.5 mg estradiol-17β and 50 mg P4 (Laboritorio Rio de Janeiro, Argentina). Superstimulatory treatments were initiated on Day 4, with a total dose of 320 mg (cows) or 200 mg (heifers) NIH-FSH-P1 (Folltropin-V; Bioniche Animal Health, Inc., Belleville, Ontario, Canada) in twice daily i.m. injections over 4 days. All cows received PGF treatment (150 μD(+)cloprostenol: Ciclase; Syntex) in the morning and afternoon of Day 6 and were randomly divided to have DIB devices removed at the time of the second PGF treatment (Day 6.5) or 12 h later (Day 7). On Day 8, donors were further subdivided to receive GnRH (0.050 mg Lecirelina, Gonasyn; Syntex) or no further treatment, and all cows were fixed-time AI either 60 and 72 h after the first PGF injection (0 h). All cows and heifers were examined by ultrasonography every 8 h for a period of 120 h commencing at the time of DIB removal, to determine the time and distribution of ovulations. For each cow, mean time of ovulation was used for the statistical analysis. The distributions of ovulations were compared among groups by Levene's test, and then by ANOVA (equal variances) or Friedman two-way non-parametric ANOVA (unequal variances). No significant differences were detected between cows and heifers (P > 0.13) for the parameters evaluated, and data were combined. There was no effect (P > 0.22) of treatment on the number of ovulations (GnRH: 12.6 ± 1.6 vs. no GnRH: 15.1 ± 1.1 and Day 6.5: 13.7 ± 1.3 vs. Day 7: 14.3 ± 1.5), or numbers of transferable embryos (GnRH: 5.1 ± 1.1 vs. no GnRH: 3.1 ± 0.8 and Day 6.5: 3.5 ± 0.8 vs. Day 7: 4.81 ± 0.1). However, there was a significant effect of GnRH treatment and a GnRH-by-time-of-DIB-removal interaction on the distribution of ovulations (P < 0.05; Table 1). The administration of GnRH in a superstimulatory protocol using P4 releasing devices results in earlier and more synchronous ovulations than when GnRH is not used. Table 1. Distribution of ovulations (hours after the first PGF) in superstimulated Red Angus donors treated with progesterone-releasing devices (DIB) for 6.5 or 7 days with and without GnRH treatment on Day 8

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.

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.

19 PREGNANCY RATES IN DAIRY COWS TREATED WITH INTRAVAGINAL PROGESTERONE DEVICES AND DIFFERENT FIXED-TIME AI PROTOCOLS

2006 ◽  
Vol 18 (2) ◽  
pp. 118 ◽  
Author(s):  
G. Veneranda ◽  
L. Filippi ◽  
D. Racca ◽  
G. Romero ◽  
E. Balla ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Milk Yield ◽  
Body Condition Score ◽  
Animal Health ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Treatment Groups ◽  
Lactating Dairy Cows ◽  
To Receive

Two experiments were designed to evaluate the effect of different treatments for the synchronization of ovulation on pregnancy rates following fixed-time AI (FTAI) of lactating dairy cows. In Experiment 1, 394 Holstein cows that were 61.7 � 13.6 days postpartum (range 35 to 94 days), with a milk yield of 30.7 � 6.8 liters per day (range 12.0 to 52.4 liters) and a body condition score (BCS) between 2.5 to 3.5 out of 5, were used. Cows were blocked by days postpartum and milk yield and randomly assigned to one of four treatment groups. Cows in P4+EB treatment groups received an intravaginal DIB device (1 g P4; Syntex, Argentina) and 2 mg of estradiol benzoate (EB; Syntex) i.m. on Day 0. On Day 8, DIB devices were removed, and cows received PGF (150 �g D+cloprostenol: Ciclase; Syntex), and were subdivided to receive 400 IU eCG (Novormon 5000, Syntex) i.m. or no further treatment at that time. On Day 9, all cows received 1 mg of EB and were FTAI 60 h after DIB removal. Cows in P4-Synch groups received a DIB device and 50 �g of GnRH (Lecirelina, Gonasyn; Syntex) i.m. on Day 0. On Day 7, DIB devices were removed; cows received PGF and were divided to receive 400 IU eCG i.m. or no further treatment. On Day 9, all cows received a second GnRH treatment and were FTAI 60 h after DIB removal. Blood samples were taken on Days -10 and 0 to determine plasma P4 concentrations; 93% of the cows had >1 ng/mL P4 in at least one sample. In Experiment 2, 200 lactating cows from the same farm were treated with the P4+EB+eCG and P4-Synch without eCG treatments with either a DIB or a CIDR-B (1.9 g P4; Pfizer Animal Health, Groton, CT, USA) in a 2 � 2 factorial design. Cows were examined by rectal palpation 50 days after FTAI to determine pregnancy status, and data were analyzed by chi-square Mantel-Haenszel test. There was an EB/GnRH by eCG interaction (P < 0.05) which was attributed to a higher pregnancy rate in the P4+EB+eCG group (44/98; 44.9%) than in the P4+EB without eCG group (30/100; 30.0%) and P4-Synch+eCG group (30/98; 30.6%); the P4-Synch without eCG group had an intermediate pregnancy rate that did not differ from the other treatment groups (37/98; 38.8%). In Experiment 2, no significant differences (P = 0.40) in pregnancy rates were detected between cows treated with DIB (51/100; 51.0%) or CIDR-B (42/100; 42.0%), and there was no difference (P = 0.18) between P4+EB+eCG (52/100; 52.0%) and P4-Synch without eCG (41/100; 41.0%) treated groups. Results suggest that the addition of eCG will improve pregnancy rates following FTAI in lactating dairy cows treated with EB but not in those treated with GnRH at the time of insertion and after removal of a P4 releasing device. Although treatment with P4+EB+eCG resulted in numerically higher pregnancy rates, results were not different from those obtained in the GnRH-based treatment, without the addition of eCG.

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.

8 EFFECT OF DURATION OF TREATMENT WITH PROGESTERONE VAGINAL DEVICES ON PREGNANCY RATES IN CROSS-BRED ZEBU CATTLE ARTIFICIALLY INSEMINATED AT A FIXED TIME

2006 ◽  
Vol 18 (2) ◽  
pp. 112
Author(s):  
E. Balla ◽  
D. Pincinato ◽  
D. Maraña ◽  
L. C. Peres ◽  
L. F. K. Borges ◽  
...  
Keyword(s):  
Body Condition Score ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Zebu Cattle ◽  
Duration Of Treatment ◽  
Treatment Groups ◽  
Condition Score ◽  
To Receive ◽  
Zebu Cows

Three experiments were designed to evaluate the effect of the duration of treatment with progesterone (P4) vaginal devices (1 g of P4, Triu-B; Biog�nesis, Buenos Aires, Argentina) on pregnancy rates in crossbred zebu cattle artificially inseminated at a fixed time (FTAI). In Exp. 1, 371 non-lactating multiparous crossbred zebu cows with a body condition score (BCS) between 2.0 and 3.0 out of 5 were randomly allocated to one of nine treatment groups in a 3 � 3 factorial design. On Day 0, all cows received 2 mg of estradiol benzoate (EB, Bioestrogen; Biog�nesis) i.m. and were divided into groups to receive a new Triu-B device, a once-previously-used Triu-B (2nd-use), or a Triu-B that was previously used twice (3rd-use) and in which three silicone rings (2 cm in length) impregnated with 100 mg P4 each were threaded through the wings of the device. Triu-B devices are currently approved for re-use up to three times. Cows were further subdivided to have their Triu-B devices removed on Days 7, 8, or 9. PGF (150 �g D(+)cloprostenol, Enzaprost-DC; Biog�nesis) was administered i.m. at the time of Triu-B removal, followed by 1 mg EB 24 h later; all cows were FTAI 52 to 56 h after Triu-B removal. In Exp. 2, 417 crossbred zebu heifers, 20 to 26 months of age and BCS between 2.5 and 3.5, were treated similarly to the cows in Exp. 1, except that only new or 3rd-use Triu-B were used. In Exp. 3, 836 crossbred zebu heifers, similar to those used in Exp. 2, were also treated similarly to the cows in Exp. 1, but in this case, Triu-B devices were inserted for 8, 9, or 10 days. Pregnancy rates were determined by ultrasonography 50 to 60 days after FTAI and were analyzed by logistic regression. In Exp. 1, there were no significant effects of duration of treatment [7 days: 69/137 (50.4%), 8 days: 68/139 (48.9%), or 9 days: 41/95 (43.2%); P = 0.28], or type of Triu-B used (P = 0.91; new Triu-B: 47.7%, 2nd-use: 48.9%, or 3rd-use: 47.2%). In Exp. 2, there were no significant effects of duration of treatment [7 days: 76/139 (54.7%), 8 days: 63/143 (44.1%), or 9 days: 73/135 (54.1%); P = 0.98] or type of Triu-B used (new Triu-B: 48.6% and 3rd-use Triu-B: 53.2%; P = 0.33). In Exp. 3, there was an interaction between duration of treatment and pregnancy rates (P < 0.05). Lower pregnancy rates were obtained in 9- and 10-day treatments than in 8-day treatments, but only when previously used Triu-B devices were used. Pregnancy rates were: new Triu-B for 8 days: 42/89 (47.2%), 9 days: 37/90 (41.1%), and 10 days: 41/91 (45.1%); 2nd-use Triu-B for 8 days: 51/103 (49.5%), 9 days: 39/104 (37.5%), and 10 days: 39/109 (35.8%); 3rd-use Triu-B for 8 days: 52/90 (57.4%), 9 days: 31/90 (34.4%), and 10 days: 25/70 (35.7%); P < 0.01. Results demonstrate that treatment of crossbred zebu cattle with P4 devices for 7 to 10 days results in comparable pregnancy rates when new Triu-B devices are used. However, pregnancy rates decreased when previously used Triu-B devices were inserted for more than 8 days.

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.

20 PREGNANCY RATES IN SUCKLED BEEF COWS SYNCHRONIZED WITH PROGESTERONE INTRAVAGINAL DEVICES AND RECEIVING eCG FOURTEEN DAYS AFTER BREEDING

2010 ◽  
Vol 22 (1) ◽  
pp. 168 ◽  
Author(s):  
L. Cutaia ◽  
M. Ramos ◽  
P. Chesta ◽  
G. A. Bó
Keyword(s):  
Body Condition ◽  
Bos Taurus ◽  
Body Condition Score ◽  
Bos Indicus ◽  
Fixed Time ◽  
Beef Cows ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Treatment Groups ◽  
Condition Score

An experiment was designed to test the following hypotheses: (1) the administration of 400IU of eCG (Novormón, Syntex SA, Buenos Aires, Argentina) 14 days after fixed-time artificial insemination (FTAI) increases pregnancy rates in cross-breed Zebu × Bonsmara suckled cows synchronized with progesterone releasing devices (DIB 0.5, 0.5 g of progesterone, Syntex SA); and (2) pregnancy rates in cows treated with estradiol or GnRH, combined with a DIB device, are not different. Primiparous suckled cows (n = 260), between 60 and 120 days postpartum (DPP) and with a body condition score between 2.0 and 2.5 (1 to 5 scale) were used. At the beginning of the experiment (Day 0), all cows were examined by rectal palpation (only 11% had a CL), received a DIB device, and were randomly allocated to 1 of 3 treatment groups. Cows in the E2 group received 2 mg of estradiol benzoate (EB) intramuscularly (i.m.) at DIB insertion and those in the two GnRH groups received 100 μg of gonadorelin (GDR Gonasyn, Syntex SA) at the same time. On Day 7, DIB devices were removed and all cows received 500 μg of cloprostenol (Ciclase DL, Syntex SA) plus 400 IU of eCG (i.m.). Cows in the E2 group received 0.5 mg of estradiol cypionate (ECP, Cipiosyn, Syntex SA) and underwent FTAI administered by one technician, using semen from 1 of 2 bulls between 52 and 56 h later. Cows in the GnRH groups received a dose of 100 μg of gonadorelin (full GnRH group) or 50 μg of gonadorelin (1/2 GnRH group) at the time of the FTAI (52 to 56 h after DIB removal). Fourteen days after FTAI cows in the 3 groups were further subdivided (3 × 2 factorial) to receive or not 400 IU of eCG i.m. Pregnancy was determined 30 days after FTAI using real-time ultrasonography. Data were analyzed by logistic regression, taking into account the effect of the synchronization treatment, eCG or noteCG, 14 days after FTAI and sire used. No differences in pregnancy rates were found (P = 0.16) among treatment groups (E2: 39/87, 43.7%, full GnRH: 38/92, 41.3%, and 1/2 GnRH: 25/81, 30.9%). However, there was a significant (P = 0.02) effect of eCG treatment 14 days after FTAI (eCG: 60/127, 47.2% v. no eCG: 41/133, 30.8%). Furthermore, bull A (77/155, 47.1%) resulted in higher pregnancy rate (P = 0.009) than bull B (28/107, 26.2%), but there were no significant interactions between bull and synchronization treatment or eCG administration 14 days after FTAI (P > 0.1). We conclude that the application of 400 IU of eCG 14 days after FTAI increases pregnancy rates in suckled Bos taurus × Bos indicus primiparous cows with fair to poor body condition score synchronized with progesterone releasing devices. Furthermore, the use of estradiol ester or GnRH at DIB insertion and removal did not affect pregnancy rates.

PSXIII-17 Supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn to beef cows during gestation: post-weaning responses of offspring reared as replacement heifers or feeder cattle

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 432-432
Author(s):  
Kelsey Harvey ◽  
Reinaldo F Cooke ◽  
Eduardo Colombo ◽  
Bruna Rett ◽  
Osvaldo Sousa ◽  
...  
Keyword(s):  
Treatment Effects ◽  
Body Condition Score ◽  
Average Daily Gain ◽  
Beef Cows ◽  
Female Progeny ◽  
Feeder Cattle ◽  
Condition Score ◽  
Haptoglobin Concentration ◽  
Eden Prairie ◽  
To Receive

Abstract Beef cows and their progeny were used to evaluate the effects of supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn during gestation: on offspring reared as replacement heifers or feeder cattle. Non-lactating, pregnant beef cows (n = 190) were ranked by parity, pregnancy type, body weight (BW) and body condition score (BCS), at 117 ± 2.2 d of gestation (d 0) and assigned to receive a supplement containing: 1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 95) or 2) an organic complexed source of Cu, Mn, Co, and Zn (AAC; Availa®4; Zinpro Corporation, Eden Prairie, MN; n = 95). From d 0 to calving, cows were maintained in a single pasture and individually offered treatments three times a week. Calves were weaned at 6 mo of age (d 367) and preconditioned for 45-d. Heifer puberty status was verified weekly (d 437 to d 619) based on plasma progesterone concentrations. Steer calves were shipped to a commercial feedlot on d 493, where they were managed as a single group until slaughter (d 724). Plasma cortisol concentration was greater (P = 0.05) in AAC calves at weaning but tended to be less (P = 0.10) on d 370 compared with INR calves. Mean plasma haptoglobin concentration was greater (P = 0.03) in INR vs. AAC calves during preconditioning, and no treatment effects were noted (P = 0.76) for preconditioning average daily gain (ADG). Puberty attainment was hastened in AAC heifers during the experiment (treatment × day; P &lt; 0.01), despite similar (P = 0.39) ADG between treatments from d 412 to 620. No treatment effects were detected (P ≥ 0.24) for steer ADG from d 412 until slaughter, nor for carcass quality traits. Therefore, supplementing Co, Cu, Zn, and Mn as organic complexed instead of sulfate sources to beef cows during the last 5 mo of gestation did not improve performance of steer progeny until slaughter, but hastened puberty attainment in female progeny reared as replacement heifers.

20 ADMINISTRATION OF FOLLICLE-STIMULATING HORMONE AT CIDR REMOVAL DOES NOT AFFECT THE PREGNANCY RATE IN A CIDR-BASED, COSYNCH PROTOCOL IN LACTATING BEEF COWS

2008 ◽  
Vol 20 (1) ◽  
pp. 90 ◽  
Author(s):  
J. Small ◽  
F. Dias ◽  
L. Pfeifer ◽  
K. Lightfoot ◽  
M. Colazo ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Pregnancy Rate ◽  
Bos Taurus ◽  
Body Condition Score ◽  
Animal Health ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Condition Score ◽  
Secondary Objective ◽  
Pfizer Animal Health

In previous studies, giving eCG at CIDR removal significantly increased the pregnancy rate after timed-AI in beef cows. However, eCG is not universally available. Therefore, we tested the hypothesis that giving pFSH at CIDR removal might improve the pregnancy rate in a CIDR-based, Cosynch protocol in postpartum, suckled Bos taurus beef cows; a secondary objective was to compare pregnancy rates when GnRH v. pLH was used to synchronize wave emergence and ovulation. This work was conducted as two experiments (separate locations). All cows were given a CIDR (containing 1.9 g progesterone; Pfizer Animal Health, Montreal, QC, Canada) on Day 0 (without regard to stage of estrous cycle or cyclicity). On Day 7, CIDRs were removed, all cows were concurrently given 25 mg PGF (Lutalyse; Pfizer Animal Health, Groton, CT, USA), half were given 20 mg pFSH (Folltropin-V; Bioniche Animal Health, Belleville, ON, Canada), and all cows were timed-AI 54 h later (Day 9). In Experiment 1, 240 cows [94 � 10.8 days postpartum; body condition score (BCS: 1 = emaciated, 9 = obese; mean � SD): 5.8 � 0.4] were used; at CIDR insertion and AI, cows were allocated to receive either 100 µg GnRH (n = 160; Cystorelin, Merial Canada Inc., Victoriaville, QC, Canada) or 12.5 mg pLH (n = 80; Lutropin-V, Bioniche Animal Health). In Experiment 2, 109 cows (59.2 � 19.5 days postpartum; BCS: 5.6 � 1.1) were used; all received 100 µg GnRH (Cystorelin) at CIDR insertion and AI. In Experiment 1, three cows that lost their CIDR were excluded; pregnancy rates after timed-AI (logistic regression, backward selection: parity, pFSH, synchronizing treatment, and their interactions) were not different between cows given pFSH v. control cows (64.7 v. 65.2%; P > 0.80), nor between cows given GnRH v. pLH (62.7 v. 69.6%; P = 0.91). However, there was an interaction (P < 0.04) between parity and the synchronizing treatment; in primiparous cows, pregnancy rates were significantly lower in those given GnRH v. pLH (59.3 v. 83.3%). In Experiment 2, pregnancy rates after timed-AI (logistic regression, backward selection: parity, pFSH, and their interaction) were not different between cows given pFSH v. control cows (38.2 v. 42.6%; P > 0.6). In conclusion, our hypothesis was not supported; giving pFSH at CIDR removal did not significantly improve the pregnancy rate in a CIDR-based, Cosynch protocol in postpartum, suckled Bos taurus beef cows.

10 TIMED ARTIFICIAL INSEMINATION PROTOCOLS TO SYNCHRONIZATION OF OVULATION IN BOS TAURUS TAURUS SUCKLING BEEF COWS

2015 ◽  
Vol 27 (1) ◽  
pp. 97
Author(s):  
G. A. Pessoa ◽  
A. P. Martini ◽  
J. M. Trentin ◽  
D. R. Dotto ◽  
H. L. D. Neri ◽  
...  
Keyword(s):  
Bos Taurus ◽  
Body Condition Score ◽  
Animal Health ◽  
Beef Cows ◽  
Treated Group ◽  
Conception Rate ◽  
Plasma Progesterone ◽  
Follicle Diameter ◽  
Condition Score ◽  
South Of Brazil

The aim of this study was to compare 3 methods for synchronization of ovulation in anestrous beef cows. The hypothesis of this study was to determine whether low doses of hCG has superior efficacy to cypionate to induce ovulation in anestrous cows and provide higher pregnancy rate in oestrus-synchronization programs. Synchronization of ovulation and conception rate to timed AI (TAI) were evaluated in anestrus Bos taurus taurus suckling beef cows 45 ± 15 days postpartum and with body condition score of 2.9 (1 to 5) maintained in a native pastured system in the south of Brazil. Females were evaluated with ultrasound on the Day 0 (D0) of the protocol (Day 0), day 8 (D8), immediately before TAI (D10), and 7 days after TAI (Day 17). All cows were synchronized with an intravaginal progesterone-releasing device (IPRD; 0.75 g of progesterone, Prociclar®, Hertape Calier Animal Health, Juatuba, Brazil) and 2 mg IM of oestradiol benzoate (EB; Benzoato HC®) on D0. On Day 8, the IPRD was removed and 150 μg of D (+) cloprostenol (Veteglan Luteolytic®), and 25 IU IM FSH/LH (Pluset®) were administered. Females of the EC (n = 84) group received 1 mg IM of oestradiol cypionate (EC; Cipionato HC®). Females on D8 of the hCG (n = 81) group received 500 IU IM of hCG (Vetecor®, Hertape Calier) at the time of TAI. The females of the EC + hCG group (n = 83) received both treatments. All cows were submitted to TAI 54 h after withdrawal of IPRD. A part of the cows (n = 102) had the ovulation evaluated every 12 h from the withdrawal of IPRD [EC (n = 34), hCG (n = 34), and hCG + EC (n = 33)]. Statistical analysis was performed using SAS PROC GLIMMIX. The dominant follicle diameter (FD) on Day 8 (8.7 ± 0.2, 8.8 ± 0.2, 8.6 ± 0.2) did not differ between treatments EC, EC + hCG, or hCG (P = 0.79). However, the FD on D10 was higher (P = 0.001) for cows treated with hCG (12.9 ± 0.3) compared with cows from the EC (11.3 ± 0.2) or EC + hCG group (11.8 ± 0.2). The interval (h) between the withdrawal of IPRD and ovulation was lower (P = 0.01) for the hCG group, (71.2 ± 1.7) compared with the groups treated with EC or EC + hCG (76.6 ± 2.18 and 74.2 ± 1.65), respectively. The ovulation rate did not differ (P = 0.61) among the EC (85.2%, 29/34), hCG (91.1%, 31/34), or EC + hCG groups (90.9%, 30/33). Corpus luteum diameter (mm) was higher (P = 0.04) on D17 for the hCG-treated group (21.4 ± 0.3) compared with others treatments (EC = 19.1 ± 0.8 or EC + hCG = 20.4 ± 0.8). However, the plasma progesterone levels on D17 were EC = 2.0 ± 0.1, hCG = 2.4 ± 0.1, and EC + hCG = 2.3 ± 0.1 ng mL–1 (P = 0.19), and the conception rate on the 28th day after TAI (EC = 43.0%; hCG = 47.0%, and EC + hCG = 48.8%; P = 0.76) was also similar. The hCG determined smallest ovulation interval, but similar rates of pregnancy were observed with both treatments.

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