Effect of chronic administration of a gonadotropin‐releasing agonist on luteal function and pregnancy rates in dairy cattle

2019 ◽  
Vol 90 (11) ◽  
pp. 1432-1443
Author(s):  
Alan Willmore ◽  
Tracy L. Davis
Keyword(s):  
Dairy Cattle ◽  
Chronic Administration ◽  
Pregnancy Rates ◽  
Luteal Function

Influence of early post partum ovulation on the re-establishment of pregnancy in multiparous and primiparous dairy cattle

1998 ◽  
Vol 10 (2) ◽  
pp. 207 ◽  
Author(s):  
M. C. A. Smith ◽  
J. M. Wallace
Keyword(s):  
Dairy Cattle ◽  
Dairy Cows ◽  
Post Partum ◽  
Pregnancy Rates ◽  
Conception Rate ◽  
Luteal Function ◽  
Fertility Treatments ◽  
Significant Relationships ◽  
Subsequent Fertility ◽  
Holstein Friesian

To investigate the influence of early ovulation after calving on subsequent fertility, milk progesterone concentrations were monitored twice weekly in multiparous (n = 87) and primiparous (n = 60) Holstein/Friesian dairy cattle. Luteal activity before 21 days post partum was defined as ‘early’. In multiparous cows, calving-to-conception interval (CCI) was longer, services per cow were more numerous and conception rate to all inseminations was lower with early luteal activity (n = 41, 16·8±0·39 days post partum) than with later luteal activity (n = 46, 37·8±2·09 days post partum); multiparous cows with early luteal activity required more exogenous fertility treatments and were more likely to fail to conceive by 100 days post partum. In contrast, in primiparous cows, no significant relationships were detected between early (n = 32) or later (n = 28) luteal activity and the CCI, number of services per cow or conception rates to all inseminations. However, primiparous cows that ovulated before 21 days post partum had fewer normal progesterone profiles. Early ovulation after calving was associated with reduced pregnancy rates and prolonged CCIs in multiparous but not in primiparous dairy cows. Extra keyword: luteal function.

scholarly journals Effect of flunixin meglumine and carprofen on pregnancy rates in dairy cattle

2010 ◽  
Vol 93 (11) ◽  
pp. 5140-5146 ◽  
Author(s):  
X. von Krueger ◽  
W. Heuwieser
Keyword(s):  
Dairy Cattle ◽  
Pregnancy Rates ◽  
Flunixin Meglumine

289 EFFECTS OF YEAR PERIOD, TECHNICAL TEAM, AND BREED ON THE PREGNANCY RATES AFTER TRANSFER OF IVF BOVINE EMBRYOS IN THE SOUTHERN REGION OF RIO DE JANEIRO

2010 ◽  
Vol 22 (1) ◽  
pp. 301
Author(s):  
B. G. Moura ◽  
J. Almeida ◽  
F. L. Lima ◽  
G. Balbi ◽  
R. Calmerani ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Dairy Cattle ◽  
Embryo Transfer ◽  
Pregnancy Rates ◽  
Chi Square ◽  
Chi Square Test ◽  
Few Data ◽  
Rectal Palpation ◽  
Fresh Embryos

The aim of the work was to study the effects of year period, technical team, breed, beef cattle and dairy cattle on the pregnancy rates in fresh embryos used in bovine transfer of IVF programs. The study was carried out at the fertilization laboratory In Vitro Nyltta Britto de Carvalho, in partnership with In Vitro Brazil, located at the Boa Vista farm, Barra do Pirai, during August 2007 to September 2008, seeking subsidies to improve the use of the technique in the field. During that period, aspirations and inovulations in 3 different periods I (August to December), II (January to April), and III (May to September) were carried out. The jobs were accomplished by 9 technical teams (A, B, C, D, E, F, G, H, and I) rendering services to the laboratory, by working with 2 beef breeds (Brahman and Nelore) and 3 dairy breeds (Gir, Girolando, and Holstein). The different breed receivers were synchronized, and in general, from 6 to 8 days after heat, they received embryo transfer, the cervical way, under low epidural anesthesia, where each female received 1 fresh embryo of IVF. All cows were submitted to gestation diagnosis by rectal palpation and ultrasonography, in general, 42 days after embryo transfer. The numbers of embryo transferred and pregnancy rates were submitted to the chi-square test, which presented significant differences (P < 0.05). There were pregnancy rates of 36.25%a (n = 960), 39.83%a (n = 1180), and 32.59%b (n = 919) in the I, II, and III periods, respectively. Among the 9 technical teams, there were verified pregnancy rates (%) of 33.51d (n = 1313), 30.30d (n = 330), 35.00cd (n = 405), 39.24cd (n = 1060), 59.25a (n = 7), 33.33d (n = 24), 53.57bc (n = 28), 43.31c (n = 157), and 58.33ab (n = 12) for A, B, C, D, E, F, G, H, and I teams, respectively. Among breeds there were rates (%) of 36.89ab (n = 412), 34.68b (n = 1286), 35.13ab (n = 74), 38.94a (n = 1140), and 37.80ab (n = 82) for Brahman, Nelore, Gir, Girolando, and Holstein, respectively. In the study, pregnancy rates (%) of 35.21b (n = 1698) in beef cattle and 38.65a (n = 1296) in dairy cattle were observed. The differences in pregnancy rates with respect to the evaluated factors, may be explained by individual, breed, and nutritional variations of the animals. There are few data in the literature with results on the embryo transfer use of IVF bovine under field conditions.

Towards the enhancement of pregnancy rate: The effect of insemination time on sperm transport, fertilization rate and embryo quality in dairy cattle

2001 ◽  
Vol 26 (1) ◽  
pp. 161-174 ◽  
Author(s):  
J.C. Dalton ◽  
S. Nadir ◽  
J. Bame ◽  
M. Noftsinger ◽  
R.G. Saacke
Keyword(s):  
Dairy Cattle ◽  
Pregnancy Rate ◽  
Embryo Quality ◽  
Fertilization Rate ◽  
Pregnancy Rates ◽  
Sperm Number ◽  
Sperm Transport ◽  
Fertilization Rates ◽  
Natural Service

AbstractTo further identify factors which influence pregnancy rates, three experiments were conducted to determine the effect of insemination time on sperm transport, fertilization rate, and embryo quality. All cows were continuously monitored for behavioural oestrus by HeatWatch®, and received AI at heat onset (0 h after the first standing event), 12 h after onset, or received natural service at 0 hfrom one of three bulls (Exp. 1). In Exp. 2, cows received AI at 0 h, 12 h, or 24 h after the first standing event. On d 6 after insemination 115 embryos(ova) (Exp. 1) and 117 embryos(ova) (Exp. 2) were recovered from single-ovulating cows. For Exp. 1, median accessory sperm values were: 1 (0 h), 10 (12 h), 27 (natural service O h) (P < 0.05). For Exp. 2, median accessory sperm values were: 1 (0 h), 2 (12 h), 4 (24 h) (P < 0.05). Fertilization rates were: 67% (0 h), 79% (12 h), 98% (natural service O h) (P < 0.05)(Exp. 1); and did not differ in Exp. 2. Embryo quality was not different in Exp. 1. In Exp. 2, percentages of excellent and good fair and poor, and degenerate embryos were: 77, 15, 8 (0 h), 52, 38, 10 (12 h), 47, 19, 34 (24 h) (P < 0.05). In Exp. 3, 30 cows were superovulated and were inseminated once at either 0 h, 12 h, or 24 h after the first standing event. On d 6 after insemination, 529 embryos(ova) were recovered. Fertilization rates were: 29% (0 h); 60% (12 h); 81% (24 h)(P < 0.01). Percentages of embryos with accessory sperm were: 5 (0 h); 8 (12 h); and 41(24 h) (P < 0.01). Embryo quality was not affected by time of AI. We conclude that the time of insemination affects: 1) sperm transport as measured by median accessory sperm number (Exp. 1 and 2) and the percentage of embryos with accessory sperm (Exp. 3); 2) fertilization rate (Exp. 1 and 3); and embryo quality (Exp. 2).

Effect of periovulatory prostaglandin F2α on pregnancy rates and luteal function in the mare

2001 ◽  
Vol 55 (9) ◽  
pp. 1891-1899 ◽  
Author(s):  
M.H.T. Troedsson ◽  
M.M. Ababneh ◽  
A.F. Ohlgren ◽  
S. Madill ◽  
N. Vetscher ◽  
...  
Keyword(s):  
Prostaglandin F2α ◽  
Pregnancy Rates ◽  
Luteal Function

scholarly journals 181COMPARISON OF THE PREGNANCY RATES AFTER SYNCHRONIZATION OF OVULATION USING GnRH AND PGF2± IN RECIPIENT DAIRY CATTLE

2004 ◽  
Vol 16 (2) ◽  
pp. 212 ◽  
Author(s):  
T. Nishisouzu ◽  
M. Sugawara ◽  
S. Aoki ◽  
K. Kishida ◽  
M. Moriyoshi ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Pregnancy Rate ◽  
Embryo Transfer ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Control Group ◽  
Corpora Lutea ◽  
Transfer Program ◽  
Chi Square ◽  
Follicle Diameter

Treatments with GnRH and PGF2α for synchronization of ovulation has resulted in acceptable pregnancy rates after fixed-time artificial insemination in dairy cows without estrus detection. The objective of the present study was to evaluate the practicability of ovulation synchronization (Ovsynch, Pursley JR et al. 1995 Theriogenology 44, 915–923) in dairy cattle using GnRH and PGF2α for the embryo transfer recipients. Dairy cattle (cows; n=100, heifers; n=88) were randomly allocated to one of two groups. The control group (cows; n=45, heifers; n=37) was composed of cows in natural estrus. The ovulation synchronization group (cows; n=55, heifers; n=51) was treated with an intramuscular injection of 100μg of GnRH at a random stage of the estrous cycle. Seven days later, the cattle received PGF2α (Cows; 25–30mg) or PGF2α analog (Heifers; 0.5mg) in order to regress the corpora lutea (CL). Forty-eight hours later, cows and heifers received a second injection of 100μg GnRH. Embryo transfer was carried out 7 days after the second injection of GnRH in the ovsynch group and 7 days after estrus in the control group. The cattle judged to have CL 17mm were classified as acceptable recipients. The size of the follicles and the CL were determined to be of estrus stage and embryo transfer by means of ultrasonography. The mean numbers of follicles and CL were analyzed by ANOVA, while pregnancy rates were analyzed by chi-square test. The results are presented in the Table. The proportion of cows and heifers determined to be acceptable embryo transfers was not different between the control group and the ovsynch group. There were no differences in the proportion of acceptable embryo transfers between the control group and the ovsynch group. Follicle diameter at the time of estrus in the control group (cows; 20.7±0.7mm, heifers; 16.8±0.5mm) were significantly larger than that of the ovsynch group (cows; 18.0±1.0mm, heifers; 14.7±0.2mm) (P&lt;0.05). Although CL diameter at the time of embryo transfer in heifers showed no differences between the control group and the ovsynch group (25.0±1.0mm v. 22.8±1.5mm), The CL diameter of the control cow group was larger than that of the ovsynch group (29.8±0.7mm v. 26.1±1.0mm, P&lt;0.05). However, no differences in pregnancy rate were seen between the control group and the ovsynch group. These results suggest that ovsynch can be effectively applied in an embryo transfer program for cattle. Table 1 Proportion of acceptable embryo transfer recipients and pregnancy rate in dairy cattle in the control ovsynch groups

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