Effects of extending the length of pro-oestrus in an oestradiol- and progesterone-based oestrus synchronisation program on ovarian function, uterine environment and pregnancy establishment in beef heifers

2018 ◽  
Vol 30 (11) ◽  
pp. 1541 ◽  
Author(s):  
J. J. de la Mata ◽  
R. Núñez-Olivera ◽  
F. Cuadro ◽  
D. Bosolasco ◽  
V. de Brun ◽  
...  

The aim of the present study was to investigate the effects of a strategy for extending pro-oestrus (the interval between luteolysis and ovulation) in an oestrus synchronisation protocol (named J-Synch) in beef heifers on follicular growth, sexual steroid concentrations, the oestrogen receptor ERα and progesterone receptors (PR) in the uterus, insulin-like growth factor (IGF) 1 and pregnancy rates. In Experiment 1, heifers treated with the new J-Synch protocol had a longer pro-oestrus period than those treated with the conventional protocol (mean (± s.e.m.) 93.7 ± 12.9 vs 65.0 ± 13.7 h respectively; P < 0.05). The rate of dominant follicle growth from the time of progesterone device removal to ovulation was greater in heifers in the J-Synch than conventional group (P < 0.05). Luteal area and serum progesterone concentrations were greater in the J-Synch Group (P < 0.05) for the 12 days after ovulation. Progesterone receptor (PGR) staining on Day 6 after ovulation in the uterine stroma was lower in the J-Synch than conventional group (P < 0.05), and the expression of PR gene (PGR) and IGF1 gene tended to be lower in J-Synch-treated heifers (P < 0.1). In Experiment 2 (n = 2349), the pregnancy rate 30–35 days after fixed-time AI (FTAI) was greater for heifers in the J-Synch than conventional group (56.1% vs 50.7% respectively). In conclusion, our strategy for extending pro-oestrus (i.e. the J-Synch protocol) significantly improves pregnancy establishment in beef heifers. This improvement was related to an increased rate of growth of the dominant ovulatory follicle, greater progesterone concentrations during the ensuing luteal phase and different uterine patterns of PGR and IGF1, which may have favoured embryo development and pregnancy establishment.

Author(s):  
N Oosthuizen ◽  
G D Melo ◽  
G E Seidel ◽  
R L Stewart ◽  
L Rowden ◽  
...  

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.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 375-376
Author(s):  
Nicky Oosthuizen ◽  
Gabriela Melo ◽  
Lawton Stewart ◽  
George Seidel ◽  
Graham Cliff Lamb ◽  
...  

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.


2018 ◽  
Vol 30 (1) ◽  
pp. 145
Author(s):  
J. B. Borges ◽  
A. B. Machado ◽  
E. Pradebon ◽  
M. Dias ◽  
M. Bernardi ◽  
...  

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.


2000 ◽  
Vol 35 (12) ◽  
pp. 2501-2509 ◽  
Author(s):  
JOÃO HENRIQUE MOREIRA VIANA ◽  
ADEMIR DE MORAES FERREIRA ◽  
WANDERLEI FERREIRA DE SÁ ◽  
LUIZ SÉRGIO DE ALMEIDA CAMARGO

The aim of this study was to investigate the follicular dynamics during estrous cycle in Gir breed (Bos indicus) cows. Follicular growth and atresia during estrous cycle were evaluated using a portable ultrasound device. Luteal activity was evaluated by serum progesterone levels. Cycles with two (6.67%), three (60.00%), four (26.67%) and five (6.67%) follicular waves were observed. There was no difference (P>0.05) in dominant or subordinate follicles growth or atresia rates among follicular waves. The maximum diameter of the ovulatory follicle was higher than the diameter of the other dominant follicles in cycles with four waves, and higher than the diameter of the second dominant follicle in cycles with three waves (P<0.05). There was no difference (P>0.05) in estrous cycle length (21.11±1.76 and 22.25±1.71 days) or progesterone levels during diestrous (4.48±1.45 and 5.08±1.40 ng/mL) between cycles with three or four waves. Follicular dynamics in Gir cattle is characterized by a higher incidence of cycles with three or four waves, associated with a low persistence of the dominant follicle.


2004 ◽  
Vol 16 (2) ◽  
pp. 128 ◽  
Author(s):  
M.G. Colazo ◽  
J.A. Small ◽  
D.R. Ward ◽  
N.E. Erickson ◽  
J.P. Kastelic ◽  
...  

The objective was to investigate the effect of presynchronization with PGF prior to a Cosynch protocol on estrus synchrony, CL and preovulatory follicle diameters and pregnancy rate following timed-AI (TAI) in beef heifers. Cycling beef heifers (n=148) were treated with 100μg GnRH i.m. (Cystorelin, Merial Canada Inc., Victoriaville, Quebec, Canada) on Day 0, 500μg cloprostenol i.m. (PGF; Estrumate, Schering Plough Animal Health, Pointe-Claire, Quebec, Canada) on Day 7, and GnRH concurrent with TAI on Day 9 (54h after PGF). Half of the heifers (Control) received the first GnRH treatment at random stages of the estrous cycle, while the other half (Presynch) received two injections of PGF 11 days apart, with the first injection of GnRH 11 days after the second injection of PGF. Estrus detection was done between the first GnRH and 12h after PGF, and heifers detected in estrus were inseminated (and considered nonpregnant to TAI), while all other heifers were TAI. Heifers were examined by transrectal ultrasonography for CL and follicle development, and confirmation of pregnancy. Data were compared between groups using Student’s t-test and chi-square procedures. The numbers of heifers in estrus early (after first GnRH and before TAI) was higher in the Control group than in the Presynch group (18/74 v. 2/74, respectively; P&lt;0.0001). Mean (±SD) diameters of the dominant follicle (12.1±3.1 v. 14.2±2.5mm) and CL (17.3±5.5v. 20.5±4.3mm) at first GnRH injection were smaller (P&lt;0.0001) and more variable (P&lt;0.03) in Control than Presynch heifers, but diameters of the preovulatory follicle (P=0.3) and CL (P=0.1) at TAI did not differ. Although the diameter of the preovulatory follicle was more variable (P&lt;0.004) in Control (5 to 19mm) than Presynch (8 to 17mm) heifers, pregnancy rate to TAI did not differ (P=0.4; 29.7 v. 36.5%, respectively). Overall pregnancy rates were 45.9 and 37.8% for Control and Presynch groups, respectively (P=0.3). Pregnancy rate tended (P&lt;0.08) to be affected by diameter of the preovulatory follicle at the time of TAI (0, 23.1, 45.7, 41.4, and 60.0% pregnant for diameters of &lt;9, 9–11, 12–14, 15–17, and &gt;17mm, respectively). Regardless of treatment, diameter of the preovulatory dominant follicle (P&lt;0.02) and CL (P&lt;0.03) 7 days after TAI was smaller, and CL diameter was more variable (P&lt;0.004), in open than in pregnant heifers (12.7±2.6v. 13.8±2.1mm, and 16.5±4.4v. 18.0±3.0mm, respectively). In summary, presynchronization with PGF prior to a Cosynch protocol reduced the proportion of heifers in estrus before TAI, suggesting that this approach may be useful in the successful application of Ovsynch or Cosynch programs in heifers. However, pregnancy rate to TAI did not differ between groups in this study. Diameter of the preovulatory follicle tended to positively affect pregnancy rate, regardless of treatment.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 131-131
Author(s):  
Kaitlin M Epperson ◽  
Jerica J Rich ◽  
Abigail L Zezeski ◽  
Saulo Menegatti Zoca ◽  
Julie Walker ◽  
...  

Abstract The objective of this study was to evaluate nutrition before and after artificial insemination (AI) on follicular dynamics, expression of estrus, and steroidogenesis. Seventy-nine beef heifers were randomly assigned to one of two dietary treatments (High;155% and Low;86% of maintenance energy) 30d prior to AI. Estrus was synchronized (PG 6-d CIDR protocol) and heifers received AI (d0) 8 to 12h following onset of estrus. On d0, heifers were randomly reassigned diets generating four Pre-x-Post-AI nutritional treatments; High-High (HH, n = 20), High-Low (HL, n = 20), Low-High (LH, n = 19), and Low-Low (LL, n = 20). Heifers remained on new diet treatments until embryo collection (flush; d7-8). Blood samples were collected daily from d-3 to d0, and on d1, 3, 5, 7 and 8 for plasma concentrations of estradiol (E2) and progesterone (P4). Dominant follicle diameter was evaluated on d-3 and d0, and CL diameter was recorded at flush. Statistical analyses were completed in SAS using the MIXED (body weight, E2, P4), GLIMMIX (expression of estrus), and GLM (ovarian parameters, interval to estrus) procedures. There were Pre-AI (P &lt; 0.0001) and Post-AI by time (P &lt; 0.0001) interactions on body weight; heifers in high and low treatments gained and lost weight, respectively, during both periods. Estradiol concentrations increased (P &lt; 0.0001) from d-3 (2.18±0.15pg/mL) to d0 (6.05±0.04pg/mL). Pre-AI diet increased the proportion of heifers in estrus (80±6.3% vs. 59±7.9%; P = 0.05), and dominant follicle size (11.7±1.42mm vs. 10.68±1.33mm; P = 0.0016) in High vs. Low, respectively. Additionally, High Pre-AI heifers had greater P4 after AI compared to Low Pre-AI heifers (4.85±0.37ng/mL vs. 3.53±0.38ng/mL; P = 0.015). Post-AI treatment did not influence concentrations of P4 (P = 0.88). There was no effect of Pre, Post or Pre-x-Post-AI treatment on initial follicle size, follicle growth rate, E2 concentrations, interval to estrus, or CL size at flush (P &gt; 0.10). In conclusion, nutrient restriction before AI negatively impacted ovarian function, steroidogenesis, and expression of estru.


2021 ◽  
Author(s):  
Aitor Fernandez-Novo ◽  
Sergio Santos-Lopez ◽  
Jose Luis Pesantez-Pacheco ◽  
Natividad Pérez Villalobos ◽  
Ana Heras-Molina ◽  
...  

Abstract Background In beef herds, increasing animal welfare, improving reproductive performance and easing animal management are key goals in farm economics. This study explored whether delaying the removal of the intravaginal progesterone device by 24 h in heifers synchronized with a 5d Co-synch 72 h protocol could improve reproductive efficiency of fixed-time artificial insemination (FTAI). In Experiment 1, we examined whether such a modified protocol would provide an acceptable, total synchronization rate (TSR) in cycling Holstein heifers. Heifers (13.4 ± 0.69 mo.) were randomly assigned to the standard 5d Co-synch 56 h protocol (5dCo56; n = 10), the standard 5d Co-synch 72 h protocol (5dCo72; n = 17), or the modified 5d Co-synch 72 h protocol, in which removal of the progesterone device was delayed by 24 h (6dCo48; n = 19). Heifers were considered synchronized (TSR) if serum progesterone value > 1.0 ng/mL and the corpus luteus (CL) was detectable by ultrasonography on Day 5, if progesterone < 1.0 ng/mL and at least one follicle had a diameter > 8 mm on Day 7.5, and if progesterone > 1.0 ng/mL and CL was detectable on Day 15. In Experiment 2, 309 cycling beef heifers on 18 commercial farms were subjected to the 5d Co-synch 72 h or 6d Co-synch 48 h protocol and conception rate (CR) studied. Results In experiment 1, the three protocols in dairy heifers led no differences on TSRs of 80.0% (5dCo56), 88.2% (5dCo72) and 89.5% (6dCo48). In experiment 2, the CR from the beef heifers, observed during two consecutive reproductive seasons did not differ: 59.7% for 5dCo72 and 62.0% for 6dCo48 (P = 0.907). Heifer age, body condition score or stress score did not significantly affect conception rate. Conclusions These results suggest that delaying removal of the intravaginal progesterone device by 24 h during the standard 5d Co-synch 72 h protocol provides satisfactory results without reducing reproductive efficiency of heifers.


Author(s):  
Juan Patricio Anchordoquy ◽  
Santiago Nicolás Lorenti ◽  
Gustavo Sebastián Polero ◽  
Nicolás Agustín Farnetano ◽  
Diana Esther Rosa ◽  
...  

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 849
Author(s):  
Aitor Fernandez-Novo ◽  
Sergio Santos-Lopez ◽  
Jose Luis Pesantez-Pacheco ◽  
Natividad Pérez-Villalobos ◽  
Ana Heras-Molina ◽  
...  

In beef herds, increasing animal welfare, improving reproductive performance and easing animal management are key goals in farm economics. We explored whether delaying the removal of the intravaginal progesterone device by 24 h in heifers synchronized with a 5d Co-synch 72-h protocol could improve reproductive efficiency of fixed-time artificial insemination (FTAI). In experiment 1, we examined the total synchronization rate (TSR) in cycling Holstein heifers. Heifers (13.4 ± 0.69 mo.) were randomly assigned to the standard 5d Co-synch 56-h protocol (5dCo56; n = 10), 5d Co-synch 72-h (5dCo72; n = 17), or the modified 5d Co-synch 72-h protocol, in which removal of the progesterone device was delayed by 24 h (6dCo48; n = 19). In experiment 2, 309 cycling beef heifers on 18 commercial farms were subjected to the 5d Co-synch 72-h or 6-d Co-synch 48-h protocol and conception rate (CR) studied. In experiment 1, the three protocols led no differences on TSRs of 80.0% (5dCo56), 88.2% (5dCo72), and 89.5% (6dCo48). In experiment 2, the CR from the beef heifers, observed during two consecutive reproductive seasons did not differ: 59.7% for 5dCo72 and 62.0% for 6dCo48 (p = 0.907). Therefore, delaying removal by 24 h provides satisfactory results without reducing reproductive efficiency of heifers.


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