Cookies on Animal Science Database

Like most websites we use cookies. This is to ensure that we give you the best experience possible.

 

Continuing to use www.cabi.org  means you agree to our use of cookies. If you would like to, you can learn more about the cookies we use.

Animal Science Database

Supporting your research in animal production, welfare and health

 Sign up to receive our Veterinary & Animal Sciences eNewsletter, book alerts and offers direct to your inbox.

Results per page:

Search results

Abstract

This is a review of the physiology and endocrinology of the estrous cycle and how ovarian physiology can be manipulated and controlled for timed artificial insemination (TAI) in beef and dairy cattle. Estrus detection is required for artificial insemination (AI), but it is done poorly in dairy...

Author(s)
Colazo, M. G.; Mapletoft, R. J.
Publisher
Canadian Veterinary Medical Association, Ottawa, Canada
Citation
Canadian Veterinary Journal, 2014, 55, 8, pp 772-780
Abstract

Ovulation of an early-stage dominant follicle induced by exogenous GnRH reportedly results in a reduced ovulatory follicle size and fertility in beef and dairy cattle. Objectives were to examine factors associated with ovulatory follicle diameter and the relationship between ovulatory follicle...

Author(s)
Colazo, M. G.; Behrouzi, A.; Ambrose, D. J.; Mapletoft, R. J.
Publisher
Elsevier, New York, USA
Citation
Theriogenology, 2015, 84, 3, pp 377-383
Abstract

In the present study, we tested the hypotheses that oocyte competence is compromised by a longer duration of follicular growth and that it is not affected by FSH starvation. Cows were allocated to short FSH (n=14), FSH starvation (n=13) and long FSH (n=13) groups. The first two groups were given...

Author(s)
Dias, F. C. F.; Costa, E.; Adams, G. P.; Mapletoft, R. J.; Kastelic, J.; Dochi, O.; Singh, J.
Publisher
CSIRO, Collingwood, Australia
Citation
Reproduction, Fertility and Development, 2013, 25, 3, pp 523-530
Abstract

The objective was to determine the effect of plasma progesterone concentration and the duration of proestrus during growth of the ovulatory follicle on fertility in beef cattle. Heifers (N=61) and postpartum cows (N=79) were assigned randomly to four groups in a two-by-two design involving...

Author(s)
Dadarwal, D.; Mapletoft, R. J.; Adams, G. P.; Pfeifer, L. F. M.; Creelman, C.; Singh, J.
Publisher
Elsevier, New York, USA
Citation
Theriogenology, 2013, 79, 5, pp 859-866
Abstract

The development of treatments that control follicular wave dynamics during the bovine oestrous cycle has resulted in interesting possibilities for the precise control of follicular wave emergence and the time of ovulation. For superstimulation, follicular wave emergence can be controlled by...

Author(s)
Bó, G. A.; Baruselli, P. S.; Chesta, P. M.; Martins, C. M.
Publisher
Elsevier, New York, USA
Citation
Theriogenology, 2006, 65, 1, pp 89-101
Abstract

Two experiments evaluated the effects of timing of the induction of ovulation in superstimulated lactating Holstein donor cows that were fixed-time artificially inseminated. Secondary objectives were to evaluate the effects of the timing of progesterone (P4) device removal (Experiment 1) or the...

Author(s)
Martins, C. M.; Rodrigues, C. A.; Vieira, L. M.; Mapletoft, R. J.; Bó, G. A.; SáFilho, M. F.; Baruselli, P. S.
Publisher
Elsevier, New York, USA
Citation
Theriogenology, 2012, 78, 5, pp 974-980
Abstract

The objective was to determine the effects of the duration of progesterone exposure during the ovulatory wave on fertility (pregnancy rate) in beef cattle. We tested the hypothesis that short-progesterone exposure during the growing and early-static phase of the ovulatory follicle (analogous to the ...

Author(s)
Dias, F. C. F.; Mapletoft, R. J.; Kastelic, J. P.; Adams, G. P.; Colazo, M. G.; Stover, B. C.; Dochi, O.; Singh, J.
Publisher
Elsevier, New York, USA
Citation
Theriogenology, 2012, 77, 2, pp 437-444
Abstract

Three experiments were conducted to determine the effects of presynchronization and treatment with equine chorionic gonadotropin (eCG) on corpus luteum (CL) and ovarian follicular development, plasma progesterone concentrations, and pregnancy rates in beef heifers subjected to a gonadotropin...

Author(s)
Small, J. A.; Colazo, M. G.; Kastelic, J. P.; Erickson, N. E.; Mapletoft, R. J.
Publisher
Agricultural Institute of Canada, Ottawa, Canada
Citation
Canadian Journal of Animal Science, 2010, 90, 1, pp 23-34
Abstract

The objective of this study was to determine the effects of low versus physiologic plasma progesterone concentrations during the ovulatory wave on fertility in cattle. Suckled beef cows (Bos taurus; n=129) and pubertal heifers (Bos taurus; n=150) at random stages of the estrous cycle were given a...

Author(s)
Pfeifer, L. F. M.; Mapletoft, R. J.; Kastelic, J. P.; Small, J. A.; Adams, G. P.; Dionello, N. J.; Singh, J.
Publisher
Elsevier, New York, USA
Citation
Theriogenology, 2009, 72, 9, pp 1237-1250
Abstract

56 cows received a norgestomet implant and an injection of norgestomet and oestradiol valerate; half (n = 28) received 500 IU equine chorionic gonadotropin (eCG) at implant removal, 9 days later. A third group (n = 25) received 2 injections of cloprostenol (500 µg) 11 days apart. The percentage of...

Author(s)
Kastelic, J. P.; Olson, W. O.; Martinez, M.; Cook, R. B.; Mapletoft, R. J.
Citation
Canadian Veterinary Journal, 1999, 40, 3, pp 173-178

Refine Results

Sort Order
Author
Geographical Location
Item Type
Organisms
Subject Topics