Presynch-Heatsynch: A New Approach to Improve Ovarian and Fertility Responses in Water Buffalo (Bubalus bubalis)

2021 ◽  
Author(s):  
Harmeet Singh Sandhu ◽  
Shahbaz Singh Dhindsa ◽  
Harpreet Singh ◽  
Mrigank Honparkhe ◽  
Prahlad Singh
Keyword(s):  
Fixed Time ◽  
Estradiol Benzoate ◽  
Bubalus Bubalis ◽  
Gnrh Analogue ◽  
Dominant Follicle ◽  
New Approach ◽  
Follicle Diameter ◽  
Group I ◽  
Follicle Size ◽  
Group Ii

Background: Standard estrus synchronization regimens resulted in variable outcomes in buffaloes. The present study evaluated ovarian and fertility responses following presynchronization in Heatsynch protocol administered in postpartum buffaloes. Methods: In group-I (Presynch-Heatsynch group, n = 30), PGF2α was administered on days -14 and -2. Then, GnRH analogue, PGF2α (Cloprostenol) and Estradiol benzoate were administered on day 0, 7 and 8, respectively followed by fixed-time artificial insemination (FTAI) 48 hours later. In group-II (Heatsynch group, n = 30), rest protocol was same, except that first two PGF2α injections were not administered. Result: The progesterone concentrations differed (P less than 0.01) between the two groups on days -2, 0 and 7. Post-treatment, progesterone profiles were also higher in pregnant compared to non-pregnant buffaloes in both the groups except on day 10. CL diameter differed (P less than 0.01) between groups on days -2, 0 and 7. It was larger in pregnant than non-pregnant buffaloes on day 7 in both the groups. Dominant follicle diameter remained larger on days -2, 0 and 8 in group-I than -II. Buffaloes getting pregnant had a larger (P less than 0.01) dominant follicle size on the day of FTAI in group-I than of group-II. Ovulatory response of 93.33 and 90.00% was observed in group-I and II. The conception rate was higher (66.66 vs. 40.00%; P less than 0.05) in group-I than Group-II. Presynchronization improved reproductive efficiency in Heatsynch treatment and may aid for better fertility in buffaloes.

30 OVULATION AND PREGNANCY RATES IN CYCLING NELLORE HEIFERS AFTER FIXED-TIME ARTIFICIAL INSEMINATION PROTOCOLS USING DIFFERENT CONCENTRATIONS OF PROGESTERONE, ASSOCIATED OR NOT WITH eCG

2010 ◽  
Vol 22 (1) ◽  
pp. 173
Author(s):  
M. F. Pegorer ◽  
R. L. Ereno ◽  
R. A. Satrapa ◽  
C. M. Barros
Keyword(s):  
Hormonal Treatment ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Repeated Measurements ◽  
Blood Levels ◽  
Dominant Follicle ◽  
Device Removal ◽  
Follicle Diameter ◽  
Intravaginal Device

The objective of the present study was to evaluate the influence of different P4 concentrations, associated or not with eCG, in the ovulation and pregnancy rates of Nellore heifers submitted to hormonal protocols for FTAI. In experiment (exp.) 1, heifers (n = 15) presynchronized with a hormonal treatment were randomly allocated in 4 groups. At the time of intravaginal device insertion (Day 0) all animals received 2 mg of estradiol benzoate (EB) and a intravaginal progesterone-releasing device containing 0.558 g of P4 (Triu®, Biogenesis Bago, Buenos Aires, Argentina; group 0.5G, n = 4) or 1g of P4 (Cronipres®, Biogenesis Bago; group 1G, n = 4), or 0.558 g of P4 and PGF2α (150 μg of D-cloprostenol, group 0.5G/PGF, n = 4), or 1 g of P4 and PGF2α (group 1G/PGF, n = 3). Eight days later (Day 8), PGF2α (150 μg D-cloprostenol) was administered to all heifers, and the P4 source was removed. Twenty-four hours after removing the intravaginal device (Day 9), the heifers were treated with EB (1 mg, i.m.). Blood samples were collected on Days 0, 1, 2, 4, 8, and 10 to evaluate plasma P4 concentration. In exp. 2, cycling Nellore heifers (n = 292) were treated with the same protocols as in the exp. 1. However, 30 to 36 h later all animals were FTAI on Day 10. In exp. 3, heifers (n = 459) received the treatments described for groups 0.5G/PGF and 1G/PGF associated with 300 IU of eCG (i.m. groups 0.5G/PGF/eCG and 1G/PGF/eCG) at the time of intravaginal device removal (Day 8). In a subset of heifers from each group, ovarian ultrasonography was performed to determine the diameter of the dominant follicle on Day 9 (exp.3) and the ovulation rate on Day 12 (exp. 2 and 3). ANOVA for repeated measurements was used to compare P4 levels, and the binary variables (ovulation and pregnancy rates) were analyzed by logistic regression. In exp. 1, P4 concentrations were higher in animals that received 1.0 compared with 0.558 g of P4, and lower in heifers that received PGF2α on Day 0. In both exp. 2 and 3 there were no significant differences in ovulation (65 to 77%) and pregnancy (exp.2: 26 to 33%; exp.3: 39 to 43%) rates among the several groups. In exp. 3, the animals that received 0.558 g of P4 had a larger diameter of the dominant follicle on Day 9 compared with heifers treated with 1.0 g (10.3 ± 0.2 v. 9.3 ± 0.2 mm; P < 0.01). It is concluded that reduction of P4 concentration in the intravaginal device or the administration of PGF2α at the beginning of the treatments decreases blood levels of P4 between Days 1 and 8 of the FTAI protocols. However, although the use of intravaginal devices with lower P4 contributed to increase the dominant follicle diameter on Day 9, there was no significant increase on ovulation and pregnancy rates. Additionally, the association of eCG with FTAI protocols did not improve follicular growth or ovulation and pregnancy rates. Supported by FAPESP (Sao Paulo, Brazil).

scholarly journals The effect of GnRH analogue on the fertility of Prostaglandin F2-? induced- oestrus cows

2016 ◽  
Vol 31 (2) ◽  
pp. 60-69
Author(s):  
SK Bhowmik ◽  
MGS Alam ◽  
M Shamsuddin ◽  
M Khatun
Keyword(s):  
Body Weight ◽  
Body Condition Score ◽  
Fixed Time ◽  
Favourable Effect ◽  
Gnrh Analogue ◽  
Group Iii ◽  
Group I ◽  
Condition Score ◽  
Group Ii ◽  
Zebu Cows

The effect of GnRH analogue (gonadorelin) was studied on the fertility of 35 postpartum anoestrus zebu cows and their crosses (Friesian, Sahiwal, Sindhi). Age (4-15 years), body weight (125-375 kg), body condition score (1.5-3; 1-5 scale), parity (1-9), postpartum intervals (4-12 months) of the cows were recorded. Oestrus was synchronized with two injections of PGF2-? analogue (Luprostinol, 15 mg) intramuscularly (i.m.) 10 days apart. The cows were divided into Group I (n = 11), Group II (n = 12) and Group III (n = 12). In Group I, 8 cows with oestrus were inseminated without gonadorelin treatment. In group II, 6 cows in oestrus were treated with gonadorelin (0.25 mg) i.m. just prior to insemination. In group III, 3 days after the second injection of luprostinol, cows with smooth ovaries were treated with gonadorelin followed by luprostinol injection 9 days later, which resulted in oestrus in 8 of the 12 cows, which were inseminated. Cows without oestrus signs were inseminated at fixed-time (72 and 96 hours after the last luprostinol injection). In group I, II and III, 5, 6 and 8 cows became pregnant, respectively (P>0.05). More cows became pregnant at observed oestrus (68.2%) than at fixed-time insemination (30.8%; P<0.05). Insemination in observed oestrus is more effective than at fixed-time. GnRH analogue may have favourable effect on the induction of oestrus by PGF2-? analogue.Bangl. vet. 2014. Vol. 31, No. 2, 60-69

scholarly journals The Effect of A PRID®Delta-Based Estrus Synchronization Protocol On Pregnancy Rates In Cows With No Estrus Symptoms

2022 ◽  
Author(s):  
Murat Can Demir ◽  
Cihan Kaçar ◽  
Umut Çağın Arı ◽  
Semra Kaya ◽  
Oğuz Merhan ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Artificial Insemination ◽  
Prostaglandin F2α ◽  
Pregnancy Rates ◽  
Dominant Follicle ◽  
Serum Progesterone ◽  
Blood Samples ◽  
Follicle Diameter ◽  
Follicle Size ◽  
Equine Chorionic Gonadotropin

Abstract The present study aimed to determine the effects of progesterone-based gonadotropin-releasing hormone (GnRH), prostaglandin F2α (PGF2α), and equine chorionic gonadotropin (eCG) injections on progesterone profiles and pregnancy rates in cows with no estrus symptoms within 60 days after parturition. A total of 80 cows were included in the study. All animals had the progesterone-releasing device PRID®Delta placed intravaginally for nine days with an injection of GnRH. On the eighth day, PGF2α was injected, and PRID®Delta was removed from the vagina on day nine. Artificial insemination was carried out 60 hours after PRID®Delta removal. In half of the animals (n = 40), 600 IU of eCG was injected when PRID®Delta was removed on the ninth day before artificial insemination 60 hours later. Blood samples were taken from the tail vein on days 0 and 8 to determine progesterone levels. The pregnancy rate in the group that received eCG was 37.5%, while it was 27.5% in those that did not (P = 0.4). While the dominant follicle diameter was 15.5 mm in cows injected with eCG during timed artificial insemination, the follicle diameter was 12.4 mm in cows with no eCG injection (P <0.001). There were no differences in serum progesterone values in blood samples taken until the time of artificial insemination. However, progesterone values in the blood taken during artificial insemination were 0.94 ng/ml in the eCG- group and 0.72 ng/ml in the eCG+ group (P <0.05). As a result, it was determined that eCG injections, in addition to progesterone-based GnRH and PGF2α applications, increased the pregnancy rates in cows without symptoms of estrus. The dominant follicle diameter was larger in cows treated with eCG during artificial insemination; however, follicle size did not increase the pregnancy rate.

109 Pre-synchronization and reutilization of progesterone devices during a 6-day CO-Synch protocol for fixed-time artificial insemination in beef heifers

2021 ◽  
Vol 33 (2) ◽  
pp. 161
Author(s):  
E. R. Canadas ◽  
B. J. Duran ◽  
G. Machado ◽  
A. Nall ◽  
S. E. Battista ◽  
...  
Keyword(s):  
Artificial Insemination ◽  
Mixed Models ◽  
Generalized Linear Mixed Models ◽  
Fixed Time ◽  
P Value ◽  
Beef Heifers ◽  
Follicle Diameter ◽  
Follicle Size ◽  
Gonadotrophin Releasing Hormone ◽  
Intravaginal Device

Ovulatory response to the initial gonadotrophin-releasing hormone (GnRH) of the CO-Synch protocol is affected by circulating progesterone (P4) and follicle size. In addition, heifers that ovulate to the initial GnRH treatment have greater fertility after AI. Thus, this study determined the effect of (1) presynchronization (Presynch) before a 6-day CO-Synch protocol and (2) circulating [RCE1] (P4) on ovulatory response, oestrus expression, and pregnancies per AI (P/AI) in beef heifers. Yearling beef heifers (n=233) at three locations were randomly assigned in a 2×2 factorial design to the following treatments: (1) Presynch+6-day CO-Synch with a new P4 device; (2) Presynch+6-day CO-Synch with a once-used P4 device; (3) 6-day CO-Synch with a new P4 device; and (4) 6-day CO-Synch with a once-used P4 device. Presynch consisted of insertion of a new P4 intravaginal device (1.38g of P4) on Day −17 and removal of P4 device on Day −11 concurrently with 500µg of cloprostenol sodium (PGF). On Day −9, all heifers received either a new (New) or once-used (Used) CIDR and 100µg of gonadorelin acetate (GnRH). Six days later (Day −3), CIDRs were removed, 1000µg of PGF was administered and an oestrous detection patch applied (Estrotect). At 72h after CIDR removal, AI was performed concurrently with administration of 100µg of GnRH. Pregnancy was determined by transrectal ultrasonography 31 days after AI. A subset of heifers (n=155) was examined on Day −9 and Day −3 by ultrasonography to determine ovulation to Day −9 GnRH. Data were analysed using generalized linear mixed models (SAS 9.4; SAS Institute Inc.). Presynch heifers had larger follicle diameter on Day −9 (12.7±0.3 vs. 10.1±0.3 mm; P&lt;0.001), greater ovulatory response to Day −9 GnRH (82.5%; 66/80 vs. 56%; 42/75; P&lt;0.001), greater expression of oestrus (90.6%; 106/117 vs. 78.4%; 91/116; P&lt;0.02), and earlier oestrus (49.8±1 vs. 53.1±1 h; P&lt;0.01) compared with controls. There was a treatment×CIDR interaction on oestrous expression, such that a lesser (P&lt;0.05) percentage of control heifers with new CIDR expressed oestrus compared with all other groups (Table 1). Heifers with a used CIDR during the 6-day CO-Synch tended (P=0.08) to have greater P/AI (52.1%; 61/117) than those with a new CIDR (40.5%; 47/116). In conclusion, presynchronization before initiation of a 6-day CO-Synch increased follicle diameter, enhanced ovulatory response and oestrous expression, but did not affect fertility. The earlier onset of oestrus in presynchronized heifers suggests that the timing of AI may need to be modified. Table 1. Oestrous expression and pregnancy per AI (P/AI) in beef heifers with or without presynchronization and treated with a new or used CIDR during a 6-day CO-Synch Treatment CIDR Oestrus (%; n/n) Time of oestrus (h) P/AI (%; n/n) Control New 67.8a (40/59) 53.7±1.5a 33.9 (20/59) Used 89.5b (51/57) 52.7±1.6a 50.9 (29/57) Presynch New 94.7b (54/57) 50.9±1.4b 47.4 (27/57) Used 86.7b (52/60) 48.7±1.3b 53.3 (32/60) P-value Treatment 0.03 0.01 0.21 CIDR 0.62 0.19 0.08 Interaction 0.003 0.75 0.38 a,bValues with different superscripts differ (P&lt;0.05).

Changes in Teat Morphology (Doka Phenomenon) and Estrus Prediction in Riverine Buffaloes (Bubalus bubalis)

2019 ◽  
Author(s):  
S K Joshi ◽  
T K Mohanty ◽  
A Kumaresan ◽  
M Bhakat ◽  
S Sathapathy
Keyword(s):  
Morphological Changes ◽  
Bubalus Bubalis ◽  
North India ◽  
Research Centre ◽  
Murrah Buffaloes ◽  
Group I ◽  
Before And After ◽  
Group Ii ◽  
The Difference ◽  
The Relationship

The objective of the study was to characterize the term Doka and to capture morphological changes in teat to find out the relationship between Doka and onset of estrus in Murrah buffaloes (Bubalus bubalis). The Murrah buffaloes maintained at of Livestock Research Centre (LRC), ICAR-NDRI, Karnal were classified into two groups based on the lactation number for the study of Doka characteristics. In group I, twenty animals up to 3rd lactation were incorporated, whereas thirty animals from 4th to 5th lactation were included in group II. The period when buffaloes showed teat engorgement was called as Doka period, is the local term used by the farmers in North India that can be taken as a visual sign for prediction of estrus. The length and diameter of teats, before and after milking were measured, for both the groups during morning and evening milking and subsequently analyzed. The present study confirmed that the teat diameter (mm) before milking during Doka was significantly (plessthan0.05) higher as compared to pre Doka period in both the groups (group-I - 37.01 ±2.13 vs 28.42 ±1.64, group-II - 53.49 ±2.82 vs 41.096±2.16). The teat diameter (mm) during Doka period after milking was significantly (plessthan0.05) more in both the groups (group-I - 26.65 ±1.26 vs 24.44 ±1.16, group-II - 39.27 ±2.41 vs 35.31 ±2.17) as compared to pre Doka period. So, it can be concluded that the changes in teat diameter can safely be considered as a sign of Doka and the forthcoming heat in Murrah buffaloes. However, the difference in teat length between different stages of Doka was found to be non significant.

115 Presynchronization and reutilization of progesterone devices during a 6-day CO-Synch protocol for fixed-time artificial insemination in beef heifers

2021 ◽  
Vol 33 (2) ◽  
pp. 165
Author(s):  
E. R. Canadas ◽  
B. Duran ◽  
G. Machado ◽  
A. Nall ◽  
S. E. Battista ◽  
...  
Keyword(s):  
Factorial Design ◽  
Artificial Insemination ◽  
Fixed Time ◽  
P Value ◽  
Beef Heifers ◽  
Follicle Diameter ◽  
Follicle Size ◽  
Gonadotrophin Releasing Hormone ◽  
Intravaginal Device ◽  
Second Use

Ovulatory response to the initial gonadotrophin-releasing hormone (GnRH) of the CO-Synch protocol is affected by circulating progesterone (P4) and follicle size. In addition, heifers that ovulate to initial GnRH treatment have greater fertility after AI. Thus, the aim of this study was to assess the effect of (1) presynchronization (Presynch) before a 6-day CO-Synch protocol and (2) P4 device reuse (new vs. second use) on ovulatory response, oestrous expression, and pregnancy per AI (P/AI) in beef heifers. Yearling beef heifers (n=233) were randomly assigned in a 2×2 factorial design to the following treatments: (1) Treatment (Presynch): (1a) Presynch+6-day CO-Synch with new P4 device; (1b) Presynch+6-days CO-Synch with a once-used P4 device; (2) Control (no Presynch): (2a) 6-day CO-Synch with new P4 device; (2b) 6-day CO-synch with once-used P4 device. Presynch consisted of insertion of a new P4 intravaginal device (CIDR, 1.38g of P4; Zoetis) on Day −17 and removal of the CIDR on Day −11 concurrently with 500µg of cloprostenol sodium. On Day −9, all heifers received either a new or once-used (used) CIDR and 100µg of gonadorelin acetate (GnRH, Parnell Inc.). Six days later (Day −3) CIDRs were removed, 1000µg of PGF was administered, and an oestrous detection patch applied (Estrotect, Rockway Inc.). At 72h after CIDR removal, 100µg of GnRH and AI using 3 different sires was performed. Pregnancy was determined by ultrasonography 31 days after AI. A subset of heifers (n=151) were examined on Day −9 and Day −3 by ultrasonography to assess ovulation to Day −9 GnRH. Data were analysed using GLIMMIX (SAS 9.4; SAS Institute Inc.). Presynch heifers had larger follicle diameter on Day −9 (12.7±0.3 vs. 10.4±0.3 mm; P&lt;0.0001), greater ovulatory response (84.6%; 66/78 vs. 52.05%; 38/73; P&lt;0.0001), greater oestrus expression (90.6%; 106/117 vs. 78.4%; 91/116; P=0.03), and expressed oestrus earlier (49.8±1.0 vs. 53.1±1.1 h; P=0.01) compared with controls. There was an interaction for treatment and CIDR on oestrous expression, whereas a lesser (P=0.003) percentage of control heifers with new CIDR showed oestrus compared with all other groups (Table 1). Heifers treated with a used P4 device tended (P=0.08) to have greater P/AI (52.1%; 61/117) than those with a new CIDR (40.5%; 47/116). In conclusion, presynchronization before initiation of a 6-day CO-Synch increased follicle diameter, ovulatory response, and oestrous expression, but did not affect fertility. The earlier onset of oestrus in Presynch heifers warrants further study on timing of AI. Table 1. Oestrous expression and pregnancy per AI (P/AI) in beef heifers with or without presynchronization and treated with a new or used CIDR Treatment CIDR Oestrus (%; n/n) Time of oestrus (h) P/AI (%; n/n) Control New 67.8a (40/59) 53.7±1.5a 33.9 (20/59) Used 89.5b (51/57) 52.7±1.6a 50.9 (29/57) Presynch New 94.7b (54/57) 50.9±1.4b 47.4 (27/57) Used 86.7b (52/60) 48.7±1.3b 53.3 (32/60) P-value Treatment 0.03 0.01 0.21 CIDR 0.62 0.18 0.08 Interaction 0.003 0.78 0.38 a,bValues with different superscripts differ (P &lt; 0.05).

scholarly journals Effects of prolonging the interval from progestin removal to prostaglandin F2α injection from 16 to 17 days in a long-term estrus synchronization protocol in beef heifers

2021 ◽  
Author(s):  
N Oosthuizen ◽  
G D Melo ◽  
G E Seidel ◽  
R L Stewart ◽  
L Rowden ◽  
...  
Keyword(s):  
Prostaglandin F2α ◽  
Fixed Time ◽  
Transrectal Ultrasonography ◽  
Dominant Follicle ◽  
Beef Heifers ◽  
Treatment Groups ◽  
Follicle Diameter ◽  
Randomized Design ◽  
Angus Heifers

Abstract To determine effects of delaying the injection of prostaglandin F2α (PGF) and fixed-time artificial insemination (TAI) in the 14-d CIDR-PG protocol, 1,049 Angus heifers at six locations were enrolled in a completely randomized design. Within location heifers were randomly assigned to one of two treatment groups: 1) PG16 (n = 518), heifers received a controlled internal drug release (CIDR) insert on d 0 for 14 d, a 25-mg injection of PGF 16 d after CIDR removal (Day 30), and a 100-µg injection of gonadotropin-releasing hormone concurrent with TAI 66 ± 2 h later; or 2) PG17 (n = 531), heifers were treated the same as PG16, however, PGF was administered 17 d after CIDR removal (Day 31), and heifers were TAI 66 ± 2 h later. Estrus detection patches were applied to a subset (n = 482) of heifers at the time of PGF administration and were examined for activation at TAI. Dominant follicle diameter was determined via transrectal ultrasonography at PGF administration and TAI in a subset of heifers (n = 116). Transrectal ultrasonography was performed to determine pregnancy rates to TAI (PR/AI) between 30 and 45 d after TAI. Estrus expression prior to TAI differed by treatment where PG17 heifers had greater (P &lt; 0.01) expression of estrus than PG16 heifers (57.8 ± 6.1 vs. 43.4 ± 6.1%, respectively). Nevertheless, dominant follicle diameters at PGF and at TAI were similar (P ≥ 0.59) between PG16 and PG17 heifers. In addition, PR/AI did not differ (P = 0.29) between PG16 and PG17 treatments (50.5 ± 3.2 vs. 45.7 ± 3.1%, respectively). Results of this experiment indicate that delaying the injection of PGF and TAI in the 14-day CIDR-PG protocol increased estrus expression prior to TAI yet did not improve fertility in beef heifers.

scholarly journals PSII-29 Effects of delayed injection of prostaglandin F2α and TAI in the 14-d CIDR-PG & TAI protocol in replacement beef heifers

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 375-376
Author(s):  
Nicky Oosthuizen ◽  
Gabriela Melo ◽  
Lawton Stewart ◽  
George Seidel ◽  
Graham Cliff Lamb ◽  
...  
Keyword(s):  
Prostaglandin F2α ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Transrectal Ultrasonography ◽  
Dominant Follicle ◽  
Beef Heifers ◽  
Treatment Groups ◽  
Follicle Diameter ◽  
Randomized Design ◽  
Angus Heifers

Abstract To determine the effects of delaying the injection of prostaglandin F2α (PGF) and fixed-time artificial insemination (TAI) in the 14-d CIDR-PG & TAI protocol, 911 Angus heifers at 5 locations were enrolled in a completely randomized design. Within location heifers were randomly assigned to 1 of 2 treatment groups: 1) PG16 (n = 452), heifers received a CIDR insert on d 0 for 14 d, a 25-mg injection of PGF 16 d after CIDR removal [d 30], and a 100-µg injection of gonadotropin-releasing hormone concurrently with TAI 66 ± 2 h later; or 2) PG17 (n = 459), heifers were treated the same as PG16, however, PGF was administered 17 d after CIDR removal [d 31], and heifers were TAI 66 ± 2 h later. Estrus detection patches were applied to heifers at the time of PGF administration and were examined for activation at TAI. Dominant follicle diameter was determined via transrectal ultrasonography at PGF administration and TAI in a subset of heifers (n = 171). Furthermore, transrectal ultrasonography was performed to determine pregnancy rates to TAI (PR/AI) between 30 and 45 d after TAI. Estrus expression prior to TAI was similar (P = 0.50) between treatments (48.9 vs. 52.0%, respectively). Moreover, dominant follicle diameter at PGF and TAI was similar (P ≥ 0.43) between PG16 and PG17 heifers. Pregnancy rates to TAI did not differ (P = 0.48) between treatment groups (46.4 vs. 48.9%, respectively). The results of this experiment indicate that delaying the injection of PGF from d 30 to d 31 along with TAI in the 14-day CIDR-PG & TAI protocol had no effects on fertility parameters in beef heifers. In conclusion, the PGF injection and TAI in the 14-d CIDR-PG & TAI protocol may be delayed, providing more flexibility in scheduling without negatively affecting fertility.

scholarly journals Effect of preovulatory follicle size on cumulus cell and follicular wall transcript abundance in beef cows

2017 ◽  
Author(s):  
◽  
Jenna Marie Monnig
Keyword(s):  
Cumulus Cell ◽  
Cumulus Cells ◽  
Beef Cows ◽  
Preovulatory Follicle ◽  
Dominant Follicle ◽  
Oocyte Competence ◽  
Follicle Diameter ◽  
Follicle Size ◽  
Gonadotropin Surge ◽  
Cell Transcriptome

Gonadotropin releasing hormone (GnRH)-induced ovulation of small dominant follicles decreased pregnancy rates and increased late embryonic/fetal mortality in postpartum beef cows, which could be caused by inadequate oocyte competence and(or) maternal environment. Previous studies revealed that dominant follicle size at GnRHinduced ovulation in beef cows may affect oocyte competence, as higher fertilization rates and higher embryo quality were achieved as dominant follicle diameter at insemination increased. In addition, higher pregnancy rates and increased concentrations of circulating preovulatory estradiol and postovulatory progesterone were observed in recipient cows induced to ovulate large compared to small dominant follicles, which may affect the establishment of pregnancy. The objectives of the current study were to determine the effects of preovulatory follicle size and physiological status on the cumulus cell transcriptome (Experiment 1) and determine the effects of preovulatory follicle size and steroidogenic capacity (i.e. concentrations of circulating estradiol) on the dominant follicle wall transcriptome collected before the preovulatory gonadotropin surge (Experiment 2). In Experiment 1, ovulation was synchronized in suckled beef cows by administering an injection of GnRH on d-9, prostaglandin F2a (PG) on d-2, and a second injection of GnRH on d0. The dominant follicle was trans-vaginally aspirated on d1 and cumulus-oocyte complexes (COC) were collected. The cumulus cells were removed from the oocytes and assigned to one of the following follicle classifications based on follicle diameter and estrus expression: small (n=6; less than 11.7mm; no estrus expression), large (n=6; greater than 12.5 mm; no estrus expression), or spontaneous (n=5; 11.6-13.9 mm; estrus expression and endogenous gonadotropin surge). RNA was extracted from cumulus cells collected from pools of four oocytes and sequenced before being aligned to the Bos taurus genome (UMD3.1). When comparing the cumulus cell transcriptome of small versus large preovulatory follicles, 430 transcripts were more abundant at a false discovery rate (FDR) less than 0.10 in small follicles and 454 were more abundant in large follicles. The glycolytic pathway was enriched in the cumulus cells of large follicles compared to small follicles. In the small versus spontaneous preovulatory follicle comparison, 597 transcripts were more abundant in small follicles and 1012 transcripts were more abundant in spontaneous follicles. The steroid biosynthesis pathway (i.e. cholesterol synthesis) was enriched in the cumulus cells of spontaneous compared to small follicles. In the large versus spontaneous preovulatory follicle comparison, 541 transcripts were more abundant in cumulus cells from large follicles and 951 were more abundant in cumulus cells from spontaneous follicles. In summary, a greater abundance of transcripts encoding for members of the glycolytic pathway in large follicles and transcripts encoding for members of the steroid biosynthesis pathway in the cumulus cells of spontaneous compared to small follicles indicate that oocytes from small follicles may be less competent. Preovulatory follicle development was synchronized in Experiment 2 by administering GnRH on d-9 and PG on d-2 to non-lactating beef cows. The ovaries were harvested at slaughter 48 hr after PG (d0) and the dominant follicle collected. RNA was extracted from approximately half of the follicle wall and sequenced. Cows were divided into two classifications based on dominant follicle diameter at collection: small (n=4; less than 11.5 mm) and large (n=7; greater than 12.5 mm). Nine transcripts were more abundant in small follicles, and two transcripts were more abundant in large follicles. No significant pathways were found. The same 11 follicle walls were also divided into two classifications based on concentration of serum estradiol at 48 hr after PG: low (n=6; less than 4.0 pg/ml) and high (n=5; greater than or equal to 4.0 pg/ml). In the low estradiol classification, 281 transcripts were more abundant in the follicle wall and 40 were more abundant in the follicle wall of the high estradiol classification. No significant pathways were found. Transcripts were analyzed with PANTHER to find significant gene ontology (GO) terms. Differentially abundant transcripts in low estradiol follicles were more highly associated with mitosis, chromosome segregation, and regulation of biological processes. In summary, a small number of transcripts were differentially abundant in the follicle wall of small versus large dominant follicles prior to the preovulatory gonadotropin surge and no specific pathways were identified that might provide insight into how the physiological maturity of a dominant follicle can affect pregnancy rate. Comparisons made between follicle walls from follicles with low or high serum estradiol found a larger number of transcripts were more highly abundant in the low estradiol follicles, possibly indicating that a higher level of transcription is taking place in the low estradiol follicles, and therefore are less mature.

7 KISSPEPTIN SLOWLY ADMINISTERED DURING PROESTRUS IMPROVES FOLLICLE GROWTH AND OVULATION IN ANESTROUS COWS

2016 ◽  
Vol 28 (2) ◽  
pp. 133 ◽  
Author(s):  
G. G. Macedo ◽  
R. V. Sala ◽  
L. F. Martins ◽  
P. S. Baruselli
Keyword(s):  
Growth Rate ◽  
Body Condition Score ◽  
Prostaglandin F2α ◽  
Fixed Time ◽  
Ovulation Rate ◽  
Growth Promoter ◽  
Dominant Follicle ◽  
Follicle Growth ◽  
Growth Promoters ◽  
Follicle Diameter

This study evaluated whether kisspeptin (Kp) administered slowly from the moment of prostaglandin F2α (PGF) treatment for fixed-time AI protocol of anestrous cows provides suitable dominant follicle (DF) growth similarly to eCG. Postpartum, anestrous, primiparous Nelore cows (n = 50; <8-mm follicles with no corpus luteum) and lean (body condition score 2.7 ± 0.1; 0–5 score scale) were enrolled. On Day 0, females received an intravaginal device with 1.0 g of progesterone (Sincrogest®, Ourofino, Brazil) and 2 mg of oestradiol benzoate IM (Sincrodiol®, Ourofino, Brazil). On Day 8, the device was removed, and cows were administered 500 μg of sodic cloprostenol IM (Sincrocio®, Ourofino, Brazil) and 1 mg of oestradiol cypionate IM (E.C.P.®, Zoetis, Brazil). Females were blocked by dominant follicle diameter and allotted in following groups: (1) control (CTRL), 1.5 mL of saline IM; (2) eCG, 300 IU IM of eCG (Novormon®, Intervet, Brazil); and (3) Kp SC with an osmotic minipump (9.65 μg kg–1 of Kp diluted in saline) over 48 h. Dominant follicle growth and ovulation evaluation were performed by ultrasound at 0, 24, 48, 60, 72, 84, and 96 h after PGF treatment. Dominant follicle growth rate was calculated by difference on DF from 0 to 48 h. Ovulation dispersion was analysed by proc GLIMMIX of SAS (SAS Institute Inc., Cary, NC, USA). Follicle variables, ovulation rate, and interval from PGF to ovulation were analysed by orthogonal contrast. Differences were considered when P < 0.05, and tendencies were considered when P < 0.1. There were no difference between CTRL and growth promoters (eCG and Kp) or between growth promoters on DF diameter at 0 h, larger follicle registered from 0 h to ovulation, ovulatory DF diameter, ovulation rate, and interval between PGF treatment and ovulation (Table 1). Dominant follicle diameter at 48 h was larger for growth promoters than for CTRL. Treatment with Kp proved as efficient as eCG in the DF growth rate, with tendency (P = 0.1) to be greater than CTRL. Data from our laboratory (Sales et al. 2011 Anim. Rep. Sci. 124, 12–18.) with same model and animal profile (n = 150 per group) presented positive effect of eCG treatment for growth and size of DF. Cows treated with Kp ovulated in only 3 specific times (60, 72, and 84 h), unlike eCG (48, 60, 72, and 84 h) and CTRL (24, 48, 60, 72, 84, and 96 h; P > 0.05). Also, it is noted that Kp treatment dose and releasing does not cause negative effect on follicle growth and ovulation (down-regulation on LH releasing) or alteration on interval of PGF treatment to ovulation. Thus, synchronized anestrous cows treated with Kp delivered slowly during proestrus have similar results to eCG on follicle growth and ovulation. Table 1.Ovarian variables of anestrous Nelore cows treated with saline, eCG (300 IU), or kisspeptin (Kp; 9.65 μg kg–1). Data were analysed by orthogonal contrast, where C1 = growth promoter (eCG and Kp) v. control; C2 = eCG v. Kp

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