Effects of postpartum energy intake on pregnancy ...

Description

Citation

Title Effects of postpartum energy intake on pregnancy rates in beef cattle subjected to GnRH- or CIDR-based timed artificial insemination protocols
Author(s) J. J. Wichtel, E. Charmley, G. F. Richardson, J. L. Duynisveld, R. Lofstedt
Journal Canadian Journal of Animal Science
Date 2008
Volume 88
Issue 3
Start page 439
End page 447
Abstract Wichtel. J. J., Charinley. E., Richardson. G. F. Duynisveld. J. L. and Lofstedt. R, 2008. Effects of postpartum energy, intake on pregnancy rates in beef cattle subjected to GnRH- or CIDR-based timed artificial insemination protocols. Can. J. Anim. Sci. 88: 439-447. The objectives were to determine the effects of three levels of postpartum metabolisable energy (ME) intake on pregnancy rates in beef cattle subjected to either GnRH-based (OVS) or progestin-based (CIDR) protocols for fixed time artifical insemination (TAI). Hereford cross cows were assigned to ME and TAI treatments (within ME) on the basis of parity and predicted calving date. The postpartum grass-silage-based diet was formulated to provide either Low (93 MJ d(-1)). Medium (103 MJ d(-1)) or High (120 MJ d(1))] ME from calving (January to February) to turnout (May 25). Lactating cows [n = 175, 5.7 +/- 1.1 mean (+/- SD) body condition score at calving] were subjected to their assigned TAIprotocol: OVS [i.m. treatments of GnRH (100 mu g) on day 0, PGF(2 alpha) (25 mg) on day 7, a second GnRH on day 9 and TAI 16 to 18 h later]. or CIDR [i.m. treatment with 1 mg estratiol benzoate and 100 mg progesterone concurrent with CIDR (1.9g progesterone) insertion on day 0, PGF(2 alpha) treatment at CIDR removal on day 7, a second estradiol treatment on day 8 and TAI 28 to 30 h later). Cows were 60 +/- 13 d post-partum at the time of insemination. Lower ME intakes reduced (P 0.05) the proportion cycling (113 175 = 65%. based on serum progesterone concentrations on days -5 and -14), ovulation following TAI, or the TAI pregnancy rates (based on ultrasonography). Timed insemination pregnancy rates were greater for CIDR- than OVS-treatment (63 vs. 45%. respectively, P<0.05), regardless of ME intake.
Use/Reproduction Contact Publisher
Text http://www.islandscholar.ca/download_ds/ir%3A10/PDF/ir_10.pdf

Using APA 6th Edition citation style.

[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]

Times viewed: 363

Adding this citation to "My List" will allow you to export this citation in other styles.