Type

Journal Article

Authors

P. Lonergan
J. F. Roche
D.A. Kenny
A.C.O. Evans
M A Crowe
T Fair
M Wade
P. Duffy
N Forde
F. Carter

Subjects

Biochemistry

Topics
drug effects embryonic development blood pharmacology estrous cycle physiology pregnancy pregnancy outcome female progesterone cattle animals gonadal hormones

Effect of increasing progesterone concentration from Day 3 of pregnancy on subsequent embryo survival and development in beef heifers. (2007)

Abstract Higher systemic progesterone in the immediate post-conception period is associated with an increase in embryonic growth rate, interferon-tau production and pregnancy rate in cattle. The objective of this study was to examine the effect of increasing progesterone concentration on Day 3 on subsequent embryo survival and development. Oestrus (Day 0) was synchronised in beef-cross heifers (n=210) and approximately two-thirds of the heifers were inseminated with semen from a proven sire, while the remainder were not inseminated. In order to produce animals with divergent progesterone concentrations, half of the animals received a progesterone-releasing intravaginal device (PRID) on Day 3 of the oestrous cycle, which was left in situ until slaughter. The four treatment groups were: (i) pregnant, high progesterone; (ii) pregnant, normal progesterone; (iii) non-pregnant, high progesterone; and (iv) non-pregnant, normal progesterone. Animals were blood-sampled twice daily from Days 0 to 8 and once daily thereafter until slaughter on Days 5, 7, 13 or 16, corresponding to the 16-cell stage, the blastocyst stage, the beginning of elongation and the day of maternal recognition of pregnancy, respectively. Embryos were recovered by flushing the tract with phosphate-buffered saline and characterised by stage of development and, in the case of Days 13 and 16, measured. Data were analysed by mixed models ANOVA, Chi-square analysis and Student's t-test where appropriate. Insertion of a PRID on Day 3 increased (P<0.05) progesterone concentrations from Day 3.5 onwards. There was no difference between treatments in the proportion of embryos at the expected stage of development on Days 5 or 7 (P>0.05). While not significantly different, the proportion of viable embryos recovered was numerically greater in the high progesterone group on both Day 13 (58 v. 43%) and Day 16 (90 v. 50%). Elevation of progesterone significantly increased embryonic length on Day 13 (2.24+/-0.51 mm v. 1.15+/-0.16 mm, P=0.034) and Day 16 (14.06+/-1.18 cm v. 5.97+/-1.18 cm, P=0.012). In conclusion, insertion of a PRID on Day 3 of the oestrous cycle increased serum progesterone concentrations on subsequent days, which, while having no phenotypic effect on embryonic development on Days 5 or 7, was associated with an increase in embryonic size on Days 13 and 16.
Collections Ireland -> University College Dublin -> PubMed

Full list of authors on original publication

P. Lonergan, J. F. Roche, D.A. Kenny, A.C.O. Evans, M A Crowe, T Fair, M Wade, P. Duffy, N Forde, F. Carter

Experts in our system

1
P. Lonergan
University College Dublin
Total Publications: 190
 
2
J. F. Roche
University College Dublin
Total Publications: 111
 
3
D.A. Kenny
Teagasc
Total Publications: 138
 
4
A.C.O. Evans
University College Dublin
Total Publications: 92
 
5
M A Crowe
University College Dublin
Total Publications: 101
 
6
T Fair
University College Dublin
Total Publications: 66
 
7
P. Duffy
University College Dublin
Total Publications: 42
 
8
N Forde
University College Dublin
Total Publications: 53
 
9
F. Carter
University College Dublin
Total Publications: 19