12 OVARIAN STRUCTURES, ESTRUS EXPRESSION, AND PREGNANCY RATE IN BEEF HEIFERS USING ESTRADIOL CYPIONATE OR GnRH AS OVULATION INDUCTORS IN TIMED AI PROTOCOL

2017 ◽  
Vol 29 (1) ◽  
pp. 113 ◽  
Author(s):  
E. Pradebon da Silva ◽  
A. B. Machado ◽  
L. S. Gambin ◽  
A. V. Gonsioroski ◽  
M. da Silva ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Body Condition Score ◽  
Device Removal ◽  
Treatment Groups ◽  
Follicle Diameter ◽  
Ovulatory Follicle ◽  
Condition Score ◽  
In The Beginning ◽  
Angus Heifers ◽  
Intravaginal Device

The aim of this study was to evaluate the effect of presence of corpus luteum (CL) at the onset of timed AI (TAI) protocol, size of ovulatory follicle and oestrus expression on pregnancy rate using E2 cypionate (EC) or GnRH as ovulation inductor in Angus heifers. On day 0, heifers [n = 414; 317 ± 23 kg; 3.08 ± 0.21 body condition score (1 to 5 scale) and 22–24 months of age] received a 1-g progesterone intravaginal device (Primer®, Agener União, Brazil) and 2 mg of oestradiol benzoate, IM, (RIC-BE®, Agener União, Brazil). On day 8, the device was removed, were administered 500 μg of sodium cloprostenol, IM, (Estron®, Agener União, Brazil) and heifers were divided in 2 groups: EC [n = 213; 0.5mg EC, IM, (SincroCP®, Ouro Fino, Brazil) on day 8] and GnRH [n = 201; 25 μg of Licerelin, IM, (GestranPlus®, Agener União, Brazil) at TAI] TAI was performed 50 h after device removal. Heifers were tail painted (Tell Tail®, GEA, New Zealand) to control oestrus expression from device removal to TAI. Heifers were scanned (7.5-MHz linear transducer MediSono® P3V, USA) to determine presence of CL (Day 0), ovulatory follicle diameter (OFD; Day 10) and ovulation (Day 11). Pregnancy was diagnosed 30 days after TAI. Oestrus expression was confirmed when marking ink was removed on day 10. Data were analysed using logistic regression and ANOVA. Oestrus expression was higher (P < 0.05) in EC (93.90%, 200/213) compared to GnRH group (67.66%, 136/201). The OFD differed (P < 0.05) according to presence of CL on Day 0 (10.3 mm) or not (9.6 mm), but was similar in treatment groups. Ovulation rate did not differ in EC (85%, 17/20) and GnRH (95%, 19/20) groups. Pregnancy rates were similar (P > 0.05) between EC (52.58%, 112/213) and GnRH (59.20%, 119/201) groups; however, in heifers that expressed oestrus, rates were higher (P < 0.05) (EC = 56%, 112/200; GnRH = 71.3%, 97/136) than in those did not show (EC = 0%, 0/13; GnRH = 33.8%, 22/65). Presence of CL at onset of TAI protocol was associated with higher pregnancy (P < 0.05) in GnRH group (68%, 68/100) compared with EC (54.46%, 61/112) group, but in heifers without CL, pregnancy were similar for GnRH (50.5%, 51/101) and EC (50.5%, 51/101) groups. Heifers were also classified in 3 groups according OFD: small (≤9.5 mm), medium (9.6–11.5 mm), and large (≥11.6 mm) to verify its effect on oestrus expression and pregnancy. Medium and large OFD were implicated in higher (P < 0.05) oestrus expression [(EC = 100%, 51/51; 96.97%, 32/33) and (GnRH = 83.02%, 44/53; 97.44%, 38/39)] than small OFD [(EC = 85%, 51/60) and (GnRH = 23.8%, 15/63)]. Pregnancy was lower (P < 0.05) in small OFD groups (EC = 28.3%, 17/60; GnRH = 25.4%, 16/63). In medium and large OFD, pregnancy was similar in EC (72.55%, 37/51; 54.55%, 18/33) groups, but differed (P < 0.05) between GnRH large (82.05%, 32/39) and medium (62.26%, 33/53). Higher pregnancy was achieved in heifers with CL in the beginning of TAI protocol treated with GnRH. Size of ovulatory follicle was associated with higher oestrus behaviour and pregnancy rate in EC and GnRH treatments.

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

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

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

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.

17 PREGNANCY RATE OBTAINED WITH THE REUTILIZATION OF INTRAVAGINAL DEVICE DICO AFTER 6 DAYS OF TREATMENT FOR ESTRUS SYNCHRONIZATION IN SHEEP

2011 ◽  
Vol 23 (1) ◽  
pp. 115
Author(s):  
P. C. dos Santos-Neto ◽  
C. García-Pintos ◽  
A. Menchaca
Keyword(s):  
Pregnancy Rate ◽  
Body Condition Score ◽  
Intrauterine Insemination ◽  
Prostaglandin F2α ◽  
Follicular Development ◽  
Device Removal ◽  
Fertility Rates ◽  
Short Term ◽  
Serum Progesterone ◽  
Intravaginal Device

The new intravaginal device DICO (Dispositivo Intravaginal Caprino Ovino, 0.3 mg progesterone, Syntex, Buenos Aires, Argentina) is effective in controlling serum progesterone concentrations, follicular development and time of ovulation in sheep, even in its second use after 6 days of treatment (Vilariño et al. 2010 Small Rumin. Res. 91, 219–224). The pregnancy rate obtained with DICO in its first use is similar to that obtained with CIDR-G (Pfizer, New York, NY, USA) (abstract of García-Pintos et al. in this issue). However, pregnancy rate with the reutilisation of DICO has not been evaluated yet. The aim of this study was to determine fertility rates in ewes synchronized with a reused DICO in comparison with a reused CIDR-G. The experiment was carried out on 314 Corriedale multiparous ewes during breeding season (March, 33°S, Uruguay), with a body condition score of 3.0 ± 0.1 (scale 0–5). Ewes received a short-term-protocol using DICO (n = 139) or CIDR-G (n = 175) during 6 days, previously used for 6 days. One dose of prostaglandin F2α analogue (125 μg cloprostenol, Ciclase DL, Syntex) and 300 IU eCG (Novormon, Syntex) were given at the time of device removal. Cervical insemination (200 million spermatozoa) or laparoscopic intrauterine insemination (100 million spermatozoa) was performed with fresh semen at fixed-time 48 or 54 h from device removal, respectively. Pregnancy diagnosis was done by transrectal ultrasonography (5 MHz, Well D, Beijing, China) 40 days after insemination. Pregnancy rate was analysed by logistic regression, and number of fetus/pregnant ewes and fetus/inseminated ewes was analysed by Poisson regression. No differences were found between reused DICO and CIDR-G devices (Table 1). Overall, pregnancy rate was affected by the method of insemination (P ≤ 0.05), being lower for cervical (37.0%; 57/154) than intrauterine insemination (55.0%; 88/160). In conclusion, the reutilization of DICO devices in the short-term protocol (6 days of treatment) allows similar fertility rates compared to re-used CIDR-G devices, by both cervical and intrauterine insemination. Table 1.Fertility rate obtained with the reutilisation of DICO and CIDR in short-term protocol (6 days of treatment) in sheep

scholarly journals 312 LUTEAL MORPHOMETRIC PARAMETERS AND SONOGRAPHIC ECHOTEXTURE DURING LUTEOGENESIS PERIOD IN PREGNANT GOATS

2008 ◽  
Vol 20 (1) ◽  
pp. 236
Author(s):  
E. K. N. Arashiro ◽  
J. H. M. Viana ◽  
J. F. Fonseca ◽  
L. G. B. Siqueira ◽  
J. H. Bruschi ◽  
...  
Keyword(s):  
Body Condition Score ◽  
Correlation Method ◽  
Corpora Lutea ◽  
Portable Ultrasound ◽  
Follicle Diameter ◽  
Ovulatory Follicle ◽  
Luteal Tissue ◽  
Condition Score ◽  
Mean Size ◽  
Pixel Value

Sonographic echotexture is an important parameter for corpora lutea (CL) evaluation, since it is related to variations on vascularization and histological features of CL and, consequently, to steroidogenesis. The aim of this study was to evaluate the luteal dynamics and pixel value during the early luteogenic period in goats. Nuliparous Toggenburg females (n = 18) with an average age of 8 months, weight of 33.52 � 5.58 kg, and body condition score of 3.5 � 0.33 (1 to 5 scale) were used. Ovarian sonographic evaluations were performed daily for 21 days after natural estrus, using a portable ultrasound device (Aloka SSD 500, Aloka Co., Ltd., Tokyo, Japan) equipped with an adapted linear rectal 5-MHz probe. CL and cavity areas were measured at their largest diameter. CL area minus the cavity area was considered luteal tissue. Images were digitalized in .TIFF format, at a 1500 � 1125 resolution, using a video capture board (Pinnacle DC10, Pinnacle Systems, Mountain View, CA, USA). Images recovered on Days 6, 8, 10, and 12 of the estrous cycle were analyzed using a custom software (Quantpro�). Each image dot (pixel) received a numeric value ranging from 0 (black) to 255 (white). Representative elementary area (REA) of 5625 pixels (0.31 cm2) was defined in the luteal tissue (proposed by Van den Bygaarty et al. 1999 Can. J. Soil Sci. 7, 149–160). Due to the possibility of early luteal regression, only data from pregnant animals (14/18, 77.8%) were used. Follicle diameter, CL area, and cavity were analyzed by ANOVA, and differences among means were evaluated by Tukey's test. Correlations were established by Pearson's correlation method. Results are presented as means � SEM. Mean diameter of ovulatory follicle was 0.75 � 0.01 cm. There was no significant correlation (P > 0.05) between ovulatory follicle diameter and CL area. CL were first visualized on Day 5.68 � 0.37 after the estrus, with a mean area of 0.56 � 0.05 cm2, and progressively increased in size (P < 0.001) until Day 12, reaching a maximum area of 1.18 � 0.06 cm2. A significant (P < 0.05) pixel value increase was observed from Days 6 to 12 of the cycle (42.79 � 5.06a; 47.90 � 4.51ab; 48.33 � 4.21b; and 52.95 � 4.65b, respectively, values with the same superscript not being significantly different). There was a significant positive correlation (R = 0.54, P < 0.0001) between luteal tissue area and pixel value during the luteogenesis period. In single ovulating goats (10/14; 71.42%), the mean time for the first CL visualization was lower (4.71 � 0.15 v. 6.78 � 0.89 days; P < 0.01) and the area of the CL on Day 12 was larger (1.32 � 0.04 v. 1.03 � 0.15 cm2; P < 0.01) than in goats with two or more ovulations, but there was no difference in luteal pixel value (52.32 � 3.19 v. 53.75 � 3.90; P > 0.05). The presence of luteal cavities was observed in 89.47% (17/19) of the CLs on the first day of visualization, with a mean size of 0.30 � 0.05 cm2, representing 45.31% of the total CL area and difficult echotexture analysis. These cavities progressively regressed (P < 0.01) until Day 11 of the cycle, with an area less than 0.1 cm2. These results show that pixel values are correlated to CL development in goats, suggesting an association between CL echotexture and steroidogenic function.

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

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

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

scholarly journals Although it induces synchronized ovulation, hCG reduces the fertility of Santa Ines ewes submitted to TAI

2018 ◽  
Vol 70 (1) ◽  
pp. 122-130 ◽  
Author(s):  
L.M.K. Dias ◽  
J.N.S. Sales ◽  
P. Viau ◽  
M.B.P. Barros ◽  
S.S. Nicolau ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Ovarian Response ◽  
Control Group ◽  
Device Removal ◽  
Oestrus Cycle ◽  
Follicle Diameter ◽  
Ovulatory Follicle ◽  
Santa Inês ◽  
Synchronization Protocol

ABSTRACT The aim of this study was to evaluate hCG treatment on ovarian response and on pregnancy rate using a 9-day oestrus synchronization protocol in Santa Ines ewes. On a random oestrus cycle day, ewes received an intravaginal progesterone device (Primer-PR®, Tecnopec, Brazil). Nine days later (Day 9), 30µg of d-cloprostenol (Prolise®, Syntex, Argentina) and 250IU of eCG (Folligon®, Intervet, Brazil) were administered and the progesterone device was removed. This moment, the ewes were randomly assigned on two groups: Control Group and hCG Group. In the hCG Group, the ewes received 500IU of hCG (Vetecor®, Hertape-Calier, Spain) 24h after device removal. In the Control Group, the ewes did not receive any ovulation inductor. Control and hCG Groups ewes were inseminated 60h and 48h after device removal, respectively. There was no difference between the groups regarding the first ovulatory follicle diameter and the second ovulatory follicle. hCG Group ewes had shorter interval between device removal and ovulation (Control: 79.9±15.4h and hCG: 54.7±4.9h; P=0.001) and more synchronized ovulations. However, the treatment with hCG decreased the pregnancy rate after TAI (P=0,009). In conclusion, hCG administration improves ovulatory synchronisation, but causes a decrease in the pregnancy rate.

11 Early Induction of Luteolysis in Fixed-Time Artificial Insemination Protocols Increases Fertility in Beef Cows

2018 ◽  
Vol 30 (1) ◽  
pp. 145
Author(s):  
J. B. Borges ◽  
A. B. Machado ◽  
E. Pradebon ◽  
M. Dias ◽  
M. Bernardi ◽  
...  
Keyword(s):  
Odds Ratio ◽  
Body Condition Score ◽  
Fixed Time ◽  
Beef Cows ◽  
Binary Outcomes ◽  
Serum Progesterone ◽  
Ovulatory Follicle ◽  
Condition Score ◽  
Prostaglandin F ◽  
Intravaginal Device

Complete luteolysis is essential for pregnancy success in beef cows submitted to fixed-time AI (FTAI) protocols. The objective of this study was to evaluate the effect of prostaglandin F (PGF) administration on Day 7 compared with Day 8 of an FTAI protocol on serum progesterone (P4) concentration, oestrus behaviour, ovulatory follicle (OF) diameter, and pregnancy per AI (P/AI). A total of 469 nonlactating Angus cows [with corpus luteum (CL), n = 359 or without CL, n = 110], body condition score 2.9 ± 0.2 (1 to 5 scale), maintained on pasture were used. Cows received a 1-g progesterone-releasing intravaginal device (Reproneo; GlobalGen, Jaboticabal, Brazil) and 2 mg of oestradiol benzoate i.m. (Syncrogen; GlobalGen) on Day 0. On Day 7, animals were randomly allocated into 2 groups. Cows were treated with 500 μg of sodium cloprostenol, IM (Inducio; GlobalGen), on Day 7 (PGF7, n = 238) or Day 8 (PGF8, n = 231). Then, P4 devices were removed and 0.5 mg of oestradiol cypionate, IM (Cipion; GlobalGen) was injected in all females on Day 8. The FTAI was performed 48 to 52 h after P4 device removal. Females had sacral region painted with appropriate paint (TELL TAIL, GEA, Hamilton New Zealand) on Day 8 to detect expression of oestrus. Transrectal ultrasonography (7.5-MHz linear transducer, MediSono P3V, Wilmington, DE, USA) was performed on Day 0 to detect presence of CL, on Day 10 to measure OF diameter, and on Day 40 to diagnose pregnancy. Blood samples were collected on Days 8 and 10 to measure P4 serum concentration by radioimmunoassay. Oestrus behaviour and pregnancy rate were analysed as binary outcomes using logistic regression (Proc GLIMMIX, SAS; SAS Institute Inc., Cary, NC, USA). OF diameter and P4 concentration were submitted to analysis of variance (Proc GLIMMIX, SAS). The oestrus manifestation was greater (odds ratio = 2.9; P = 0.0002) in females of PGF7 group (91.6%; 218/238) than PGF8 group (78.8%; 182/231). The P/AI of cows that exhibited oestrus was 60.2% (241/400) v. 39.1% (27/69), resulting in higher chance (odds ratio = 2.4) of pregnancy associated with oestrus behaviour (P = 0.0014). Diameter of the OF did not differ (P = 0.0881) between PGF7 (11.7 mm) and PGF8 (11.3 mm). The P/AI was higher (P = 0.0034) for PGF7 (63.9%, 152/238) v. PGF8 (50.2%, 116/231). In group PGF7, P4 on Day 8 did not differ between pregnant (1.7 ng mL−1) and nonpregnant (1.9 ng mL−1) females. However, group PGF8 pregnant females had lower P4 concentration (2.6 ng mL−1) on Day 8 (P = 0.0005) than nonpregnant (3.4 ng mL−1) females. On Day 10, P4 did not differ between treatments (PGF7 = 0.11 ng mL−1 v. PGF8 = 0.09 ng mL−1) and did not affect fertility (P = 0.2515). According to results, OF diameter and P4 concentration on Day 10 were not influenced by the day of PGF administration; however, earlier PGF injection resulted in higher oestrus behaviour and increased fertility.

163 Treatment with gonadotrophin-releasing hormone at the time of AI in beef heifers that fail to express oestrus after an estradiol-based synchronisation protocol improves pregnancies per AI

2020 ◽  
Vol 32 (2) ◽  
pp. 208
Author(s):  
A. Butler ◽  
H. Butler ◽  
G. Cesaroni ◽  
R. Alberio ◽  
S. Perez Wallace ◽  
...  
Keyword(s):  
Pregnancy Loss ◽  
Fixed Time ◽  
P Value ◽  
Device Removal ◽  
Releasing Hormone ◽  
Condition Score ◽  
Gonadotrophin Releasing Hormone ◽  
To Receive ◽  
Angus Heifers ◽  
Intravaginal Device

Oestrus expression between progesterone (P4) withdrawal and fixed-time AI (FTAI) has been shown to improve pregnancies per AI (P/AI) by 27% in beef cattle. As a result, cattle that do not express oestrus after P4 withdrawal present a challenge to the efficiency of FTAI. The present study was designed to test the hypothesis that administration of gonadotrophin-releasing hormone (GnRH) at the time of AI in heifers that do not express oestrus can improve fertility. Two-year-old Angus heifers (n=1032) with a condition score of 2.75 to 3.5 at two locations in Argentina were used. On Day 0, heifers received an intravaginal device containing 0.5g of P4 (Cronipres, Biogenesis) and 2mg of oestradiol benzoate intramuscularly (Bioestrogen, Biogenesis). On Day 8, devices were removed and heifers received 150µg of d-cloprostenol intramuscularly (Enzaprost, Biogenesis), 0.5mg of oestradiol cipionate intramuscularly (Croni-Cip, Biogenesis), and an oestrus detection patch (Estrotect, Rockway Inc.). On Day 10, AI was performed in all heifers 50 to 54h after device removal. Heifers were categorised based on oestrus expression, and those that did not express oestrus were randomised to receive 100µg of gonadorelin acetate intramuscularly (Gonasyn, Syntex; n=158) concurrent with AI or remain as untreated controls (n=151). Pregnancy was determined using ultrasonography at Days 38 and 111 after AI. Differences in fertility were evaluated using generalised linear mixed models, and the results are shown in Table 1. Oestrus expression between device removal and FTAI was 70.1% (723/1032). Pregnancies per AI at Days 38 and 111 were different between groups (P&lt;0.01). Heifers that expressed oestrus had greater P/AI than those that did not regardless of treatment (P&lt;0.01). However, in heifers that did not express oestrus, treatment with GnRH at the time of AI resulted in greater P/AI than in control heifers (P=0.004). Similarly, P/AI at Day 111 were greater in heifers that expressed oestrus than in those that did not regardless of treatment (P&lt;0.01). Heifers that did not express oestrus and were treated with GnRH had greater P/AI than those that did not express oestrus and remained as controls (P=0.02). Pregnancy loss between Days 38 and 111 was not different between groups; however, there was a tendency (P=0.06) for greater pregnancy loss in heifers that did not express oestrus and were treated with GnRH compared with heifers that expressed oestrus. In summary, treatment with GnRH at the time of AI is a suitable strategy to improve P/AI in heifers that fail to exhibit oestrus after an oestradiol-based synchronisation protocol. However, this strategy appears to increase pregnancy loss, and thus further research is needed to confirm this observation and the mechanisms underlying it. Table 1.Pregnancies per AI (P/AI) and pregnancy loss (%; no. in parentheses) in Angus heifers based on oestrus expression and treatment with GnRH Group P/AI Day 38 P/AI Day 111 Pregnancy loss Oestrus 68.9 (498/723)A 65.2 (471/723)A 5.4 (27/498) No oestrus control 29.8 (45/151)B 28.5 (43/151)B 4.4 (2/45) No oestrus + GnRH 45.6 (72/158)C 40.5 (64/158)C 11.1 (8/72) P-value &lt;0.001 &lt;0.001 0.15 A-CValues within a column with different superscripts differ significantly (P&lt;0.05).

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.

16 FERTILITY RATE OBTAINED WITH A NEW INTRAVAGINAL PROGESTERONE RELEASING DEVICE DICO IN SHEEP

2011 ◽  
Vol 23 (1) ◽  
pp. 114
Author(s):  
C. García-Pintos ◽  
P. C. dos Santos-Neto ◽  
A. Menchaca
Keyword(s):  
Pregnancy Rate ◽  
Body Condition Score ◽  
Intrauterine Insemination ◽  
Prostaglandin F2α ◽  
Fixed Time ◽  
Fertility Rate ◽  
Device Removal ◽  
Control Serum ◽  
Significant Difference ◽  
Intravaginal Device

A new intravaginal device DICO (Dispositivo Intravaginal Caprino Ovino, 0.3 g progesterone; Syntex, Buenos Aires, Argentina) consisting of a progesterone impregnated medical silicone was developed for oestrus synchronization in sheep and goats. The effectiveness of this device to control serum progesterone concentrations, follicular development and time of ovulation has been recently reported in ewes (Vilariño et al. 2010 Small Rumin. Res. 91, 219–224); however, fertility obtained with DICO has not been evaluated yet. The aim of this study was to determine fertility rate obtained with DICO by fixed-time cervical or intrauterine insemination in sheep. The experiment was performed on a total of 569 Corriedale multiparous ewes in breeding season, with a body condition score of 3.0 ± 0.1 (scale 0–5). Ewes received a Short-term Protocol consisting of a 6 days of treatment with DICO (n = 174), CIDR-G (0.3 g of progesterone, Pfizer, NY, USA; n = 197) or sponges with 60 mg of medroxiprogesterone acetate (MAP, Syntex; n = 198). One dose of prostaglandin F2α analogue (125 μg of cloprostenol, Cilcase DL, Syntex) and 300 IU of eCG (Novormon, Syntex) was given at the time of device withdrawal. Insemination was performed 48 or 54 h after device removal by cervical (200 millions of spermatozoa) or laparoscopic intrauterine insemination (100 millions of spermatozoa), respectively. Pregnancy diagnosis was performed by transrectal ultrasonography (5 MHz, Well D, Beijing, China) 40 days after insemination. Pregnancy rate (pregnant ewes/inseminated ewes) was compared by logistic regression, and number of fetuses/pregnant ewes was analysed by Poisson regression. Regarding pregnancy rate, a significant difference (P < 0.05) was found between cervical (39.5%, 109/276) v. intrauterine insemination (58.3%, 172/295), as well as between progesterone devices (DICO: 55.7%, 97/174; CIDR-G: 55.8%, 110/197) v. MAP sponges (37.4%, 74/198). The results are shown in Table 1. In conclusion, the current study shows that the new intravaginal device DICO is useful to obtain acceptable fertility with fixed-time insemination in sheep. When cervical insemination at 48 h or intrauterine insemination at 54 h after device removal is performed, similar or better results than CIDR-G or MAP sponges are achieved, respectively. Table 1.Results obtained with DICO, CIDR and sponges after cervical or intrauterine insemination in sheep Supported by Syntex.

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