35 FERTILITY AFTER FIXED-TIME AI OR INSEMINATION AT DETECTED ESTRUS FOLLOWING CIDR SYNCHRONIZATION PROTOCOLS IN FRENCH DAIRY AND BEEF CATTLE

2010 ◽  
Vol 22 (1) ◽  
pp. 175
Author(s):  
C. Ponsart ◽  
J. Gatien ◽  
B. Besognet ◽  
P. Fanuel ◽  
P. Humblot

The CIDR synchronization protocol was introduced in France since 2008, as a 7-day intravaginal progesterone treatment (1.38 g of progesterone) coupled with AI at detected estrus. The objective of this study was to compare the synchronization, ovulation, and conception rates following fixed-timed AI (FTAI) and AI on observed heat (HAI) following a CIDR synchronization program in dairy and beef cattle under on-farm conditions. A total of 466 females from Holstein, Limousin, and Charolais breeds were synchronized from October 2008 to March 2009, and inseminated by AI technicians from 4 French cooperatives (Amélis, CECNA, COOPELSO, Groupe Altitude) with the following inclusion criteria : heifers from 14 to 28 months old, cows with 1 to 5 calvings, interval from calving from 50 to 150 days, first breeding following calving without any complication. The CIDR device was left for a 7-day period and combined with a PGF2α injection 1 day before CIDR removal and an eCG injection at the time of CIDR removal. Cows within each herd were allocated to 2 insemination groups. In the FTAI group, a single insemination was performed 56 h after CIDR removal, whereas the females from the HAI group were inseminated once from 6 to 18 h after detected estrus. For each female, cyclicity was assessed before CIDR insertion with 2 progesterone measurements assayed 10 days apart. The CIDR device was lost in 25 females during treatment. In the remaining females, estrus synchronization was estimated from a progesterone measurement 56 h after CIDR removal. Ovulation rate following CIDR programs was determined by progesterone measurements 14 days after AI. Pregnancy was diagnosed by ultrasonography on Day 35 after AI in 417 females (24 missing values). From results of cycling females prior to treatment (n = 369), synchronization rates averaged 95.6% and 94.3% in HAI and FTAI groups, respectively. Ovulation rate, calculated from 399 synchronized or noncycling females, averaged 93.4% and 91.6% in HAI and FTAI groups, respectively. Conception rate at first AI averaged 51.9% (HAI: 52.6% v. FTAI: 47.4%; P > 0.05), and conception rate following induced estrus (i.e. calculated from ovulated females only) averaged 55% (HAI: 55.3% v. FTAI: 52.2%; P > 0.05). Conception rate was mainly influenced by breed and parity, ranging from 34% in Holstein cows to 58.7% in Holstein heifers (Table 1). To conclude, fixed-time insemination can be coupled to CIDR synchronization protocols in beef and dairy cattle and can be used to as a substitute for heat detection under on-farm conditions. Table 1.Conception rates depending on breed and parity

2015 ◽  
Vol 55 (2) ◽  
pp. 180 ◽  
Author(s):  
T. J. Schatz

Previous studies have reported inconsistent results when attempting to use pre-partum supplementation to improve re-conception rates in first-lactation heifers in northern Australia. It has been speculated that where no improvement in re-conception rates was found that it may have been because supplementation was stopped before the wet season began, and the benefits from supplementation were lost when heifers lost weight between the end of supplementation and the start of the wet season. This study was conducted to determine whether re-conception rates in Brahman first-lactation heifers in the Victoria River District (VRD) could be reliably improved by pre-partum supplementation with high protein supplements (at a rate of 0.4% of liveweight per day). Re-conception rates were significantly higher in supplemented (SUP) heifers in each of the 3 years of this study (re-conception rates were an average of 42 % units higher in SUP heifers over the 3 years). It was concluded that feeding pre-partum protein supplements for a period of at least 100 days until green grass is available at the start of the wet season is a reliable method of increasing re-conception rates in first-lactation heifers in the VRD. However, even with large increases in re-conception rate, the profitability of supplementation strategies in northern Australia need to be carefully evaluated due to high on-farm costs of supplements. Profitability is also adversely affected when the feeding period is extended due to a late start to the wet season.


1980 ◽  
Vol 30 (1) ◽  
pp. 61-67 ◽  
Author(s):  
N. G. Buck ◽  
D. Light ◽  
A. D. Makobo

ABSTRACTIn three trials conducted in 3 successive years, Africander, Brahman, Tswana, Tuli and crossbred cattle were injected intramuscularly with 500 jug of cloprostenol on two occasions 11 days apart to synchronize oestrus. The cattle were inseminated 72 and 96 h after the second injection. Controls of the same breeds were exposed to natural service for a period of 22 days. In all trials the conception rate to natural service was significantly higher (P < 0·01).Conception rates to both breeding methods were highest in Tuli and crossbred cattle and lowest in the Africander and Brahman. Non-lactating cows showed higher fertility than suckling cows and maiden heifers.Vasectomized bulls used in one trial were shown to be useful in the selection of breeding cows suitable for oestrus synchronization. Further studies are justified to maximize the benefits of a potentially valuable method of breeding beef cattle in ranching conditions.


2010 ◽  
Vol 22 (1) ◽  
pp. 161
Author(s):  
J. R. S. Torres-Júnior ◽  
J. A. T. Souza ◽  
M. I. S. Silva ◽  
J. S. Costa ◽  
G. S. Lima ◽  
...  

The duration of spermatic viability in the female reproductive system in cattle is 18 to 24 hours. Therefore, the time required for sperm capacitation in different bulls demonstrated to be highly variable and may affect the adequate amount of capacitated sperm within an optimal window of time for fertilization. The aim of this study was to evaluate the conception rate in Nelore cows inseminated with semen from a single bull compared with semen from a pool of 3 bulls (Fertility Plus®, ABS Pecplan, Minas Gerais, Brazil). On a random day of the estrous cycle (Day 0), 400 Nelore multiparous cows received a progesterone intravaginal device (1 g of P4, DIB®, Intervet/Schering-Plough, Cotia, Brazil) plus 2mg of estradiol benzoate (i.m. Estrogin®, Farmavet, São Paulo, Brazil). At the time of P4 device withdrawal (Day 8), 150 (ig of d-cloprostenol (i.m. Preloban®, Intervet/Schering-Plough), 1 mg of estradiol cypionate (i.m. ECP®, Pfizer, Brazil), and 300IU of eCG (i.m. Folligon®, Intervet/Schering-Plough) were administered. At 48 to 52 h after implant removal, all cows were fixed-time inseminated (FTAI). Then, cows were homogeneously distributed based on the semen used for FTAI in 4 groups: CONV1 (conventional dose of semen from bull 1), CONV2 (conventional dose of semen from bull 2), CONV3 (conventional dose of semen from bull 3), FERT (pool of semen from bulls 1, 2 and 3 homogeneously mixed in a single dose). Both conventional and Fertility Plus batches of semen contained a total dose of 30 × 106 spermatozoa. For pregnancy diagnosis, an ultrasonographic (CHISON 500VET, USP Brasil Eletromedicina, São Paulo, Brazil) examination was performed 30 days after the FTAI. Data were analyzed using the GENMOD procedure of SAS (SAS Institute, Cary, NC, USA). There was no interaction between treatment and body condition score [using a 1 (very thin) to 5 (very fat) point scale] or AI technician. The conception rates for CONV1, CONV2, CONV3, and FERT were, respectively, 40/101 (39.6%)b, 50/99 (50.5%)ab, 46/99 (46.5%)ab, 54/101 (53.5%)a; P < 0.05. In addition, the mean of conventional v. Fertility Plus treatments presented conception rates of 136/299 (45.5%) v. 54/101 (53.5%), respectively (P = 0.14). No significant statistical differences were observed between treatments. However, this trial showed that the utilization of the new Fertility Plus technology increased the overall conception rate by 8.0%. This probably implicates a complementary effect among semen samples and provides a greater time of sperm viability in oviduct. Also it provides evidence of the individual variation in capacitation time of bulls used for composition of the pool. Pooled semen of multiple sires may improve the reproductive performance at AI in cattle and increase the potential of the beef industry to produce pregnancies and born calves.


Author(s):  
W. Haresign ◽  
R.M. Curnock ◽  
H.C.B. Reed

The current technique for artificial insemination (AI) of ewes during the breeding season necessitates the synchronisation of oestrus with progestagen sponges and PMSG, and involves depositing semen into the posterior cervix at a fixed time after sponge removal. Extensive field trials over a number of years in the UK have indicated that a single insemination using fresh diluted semen 56 h after sponge removal generally results in a conception rate of 70%, while conception rates following a single insemination of frozen-thawed semen 57 h after sponge removal have ranged from 19% to 34% (mean 28%). Giving two inseminations of frozen-thawed semen at 50 h and 60 h after sponge removal increased the overall mean conception rate, but only up to 48%. This inability to achieve acceptable conception rates with frozen-thawed semen nullifies many of the potential benefits of AI in sheep flocks.It is well established that the cervix presents a major barrier to sperm transport in the ewe, particularly when oestrus has been synchronised with progestagens and PMSG.


2021 ◽  
Vol 49 ◽  
Author(s):  
Jefferson Viana Alves Diniz ◽  
José Antonio Dell’Aqua Junior ◽  
Eunice Oba ◽  
Rosano Ramos De Freitas ◽  
Renato Mesquita Peixoto ◽  
...  

 Background:Progesterone (P4) is essential for embryonic development and maintenance of pregnancy when deficiency causes early embryonic loss. In this study, we investigated the ability of hormonal supplementation to improve the fertility of cows subjected to fixed-time artificial insemination (IATF) protocols. Here, we evaluated the effect of long-acting injectable progesterone (iP4) supplementation in the D4 after IATF on pregnancy rate and pregnancy loss in Nellore cows (Bos taurus indicus) from different reproductive categories in Western Amazonia.Materials, Methods & Results:Eight hundred thirteen animals from 5 farms were selected and distributed into 2 groups: control [GC; administration of 0.5 mL of 0.9% saline solution, intramuscularly – IM] (n = 407) and a group that received injectable progesterone (iP4) that was long-acting [GiP4; administration of 0.5 mL of iP4, 300 mg, via IM four days after IATF] (n = 406). Each group contained 3 subgroups: heifers, primiparous cows, and multiparous cows. Of the 407 animals in the CG, 103 were heifers, 107 primiparous, and 197 multiparous. Of the 406 animals in the GiP4 group, there were 101 heifers, 107 primiparous, and 198 multiparous. On a random day of the estrous cycle (D0), an intravaginal device containing 1 g of P4 and 2 mg of estradiol benzoate (BE) was inserted by intramuscular injection. On D8, the P4 device was removed and 150 μg of D-cloprostenol (PGF2α), 300 IU eCG, and 1 mg BE were administered IM. Cows were inseminated at D10, 48-52 h after procedure on D8. Pregnancy diagnosis was made between 35 and 40 days after insemination through ultrasound examination. Between 80 and 90 days after insemination, a new ultrasound examination was performed to assess early pregnancy loss. The data were processed using the SAS 9.2. The conception rate, pregnancy loss, and final conception rate were analyzed using PROC GLIMMIX according to groups (CG and GiP4), categories (heifers, primiparous and multiparous), and their interactions as variables. The differences in the means of least squares were adjusted using the Tukey–Kramer method. Statistical significance was defined as P < 0.05. The general conception rate was 46% (375/816). Regardless of the animal class, GiP4 animals (51.97%) had higher conception rates (P < 0.05) than CG (40.29%). In the subgroups (heifers, primiparous and multiparous cows), there was a difference (P < 0.05) between animals treated with iP4 (52.48%, 57.94%, and 48.48%, respectively) and those who were not (39.81%, 41.12%, and 40.10%, respectively). Gestational losses, regardless of the animal class, were higher in females in the CG (7.93%) [P < 0.05] compared to those in the GiP4 group (2.84%). Regardless of treatment with iP4, the percentage of gestational loss in heifers was significantly higher (10.64%) than that in primiparous and multiparous cows (3.77% and 2.86%, respectively). The final conception rates were higher in animals that received long-acting iP4, which increased the final pregnancy in all parity categories. Discussion: In the present study, the use of iP4 increased the pregnancy rate in Nellore females, regardless of the category. Although there has been no consensus on the use of iP4, there is an agreement that increases in the pregnancy rate are related to the moment of exogenous P4 application. In addition to influencing the pregnancy rate, reduction in pregnancy losses is also attributed to iP4 treatment, a fact demonstrated in the present study, where animals treated with iP4 had a lower pregnancy loss rate than normally occurs in beef cattle. Supplementation with long-acting iP4 increased the pregnancy rate at D35-40, reduced pregnancy losses, and increased the conception rate on D80-90 days in Nellore females reared in the Western Amazon, regardless of the animal category.Keywords: abortion, reproductive biotechnologies, Bos taurus indicus, pregnancy, progesterone supplementation.Descritores: aborto,biotecnologias reprodutivas, Bos taurus indicus, gestação, suplementação de progesterona.Título: Influência da progesterona injetável na taxa de prenhez e perda gestacional de fêmeas nelore de distintas categorias reprodutivas submetidas a inseminação artificial em tempo fixo.


2015 ◽  
Vol 36 (5) ◽  
pp. 3149
Author(s):  
Rossane Pereira da Silva ◽  
Karen Martins Leão ◽  
Moraima Castro Rodrigues ◽  
Thaisa Campos Marques ◽  
Natalia Do Carmo Silva ◽  
...  

<p>The present study evaluated the effect of administering buserelin acetate (GnRH) at the time of fixed-time artificial insemination (FTAI), along with the effect of oral administration of melengestrol acetate (MGA) after FTAI on conception rates in non-suckling Nelore cattle. In Experiment I, the effect of GnRH application at the time of FTAI was evaluated, as was administration of MGA from the 13th through the 18th day following FTAI (D24 to D29 after the initiation of the FTAI protocol). Experiment I was performed in 215 non-suckling cattle of the Nelore breed, divided into four experimental groups: Control group: 56 cows subjected to FTAI without GnRH injection; GnRH group: 51 cows subjected to GnRH at the time of FTAI; MGA Group: 57 cows subjected to FTAI without the application of GnRH with mineral supplementation and the addition of 2.28 g of MGA® Premix per cow per day from D24 to D29 after the initiation of the FTAI protocol; MGA and GnRH group: 51 cows subjected to GnRH injection at the time of FTAI, with mineral supplementation and the addition of 2.28 g of MGA® Premix per cow per day from D24 to D29 after the initiation of the FTAI protocol. In Experiment II, the effect of providing MGA five to ten days after FTAI was evaluated in 196 non-suckling pluriparous Nelore cows, divided into two groups: Control group: 104 cows subjected to FTAI, not supplemented with MGA; treated group: 92 cows supplemented with the addition of 2.28 g of MGA® Premix per cow per day from D15 to D20 after the initiation of the FTAI protocol. Diagnosis of gestation was carried out 45 days after FTAI. Both experiments were conducted using a completely randomised design and analysed via the SAS MIXED procedure. In Experiment I, the control group displayed a lower conception rate (32.1%) compared with the groups administered GnRH, MGA, and both MGA and GnRH, which were respectively provided with MGA after FTAI (45.6%), GnRH at the time of FTAI (50.9%), and the combination of the two treatments (50.9%) (P&lt;0.05). In Experiment II, the control group displayed a higher conception rate (40.38%) compared with the group receiving MGA post-FTAI (18.48%) (P&lt;0.05). It was concluded that the injection of buserelin acetate (GnRH) at the time of FTAI and the oral administration of MGA® Premix from the 13th to the 18th day after FTAI increased the conception rates in non-suckling Nelore cattle. However, when MGA® Premix was administered orally from the fifth to tenth day post-FTAI, conception rates in non-suckling Nelore cattle were reduced.</p>


2012 ◽  
Vol 24 (1) ◽  
pp. 272 ◽  
Author(s):  
Gabriel A. Bó ◽  
Lucas Coelho Peres ◽  
Lucas E. Cutaia ◽  
Danilo Pincinato ◽  
Pietro S. Baruselli ◽  
...  

Although embryo transfer technology has been used commercially in cattle for many years, the inefficiency of oestrus detection, especially in recipients, has limited the widespread application of this technology. The most useful alternative to increase the number of recipients utilised in an embryo transfer program is the use of protocols that allow for embryo transfer without the need for oestrus detection, usually called fixed-time embryo transfer (FTET). Most current FTET protocols are based on progestin-releasing devices combined with oestradiol or GnRH, which control and synchronise follicular wave dynamics and ovulation. Conception rates to a single FTET have been reported to be similar to those after detection of oestrus, but pregnancy rates are higher because these treatments have increased the proportion of recipients that receive an embryo. Recent changes to treatments for FTET, such as the administration of eCG, have resulted in increased pregnancy rates and provide opportunities to make these treatments easier to perform on farm.


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