Type

Journal Article

Authors

D Rizos
P. Lonergan
A K Kelly
C de Frutos
L O'Hara
P. Duffy
V Maillo

Subjects

Medicine & Nursing

Topics
drug effects growth development ultrasonography blood corpus luteum chorionic gonadotropin luteinization humans pharmacology physiology models statistical estrus synchronization breeding female progesterone cattle animals

Effect of hCG administration during corpus luteum establishment on subsequent corpus luteum development and circulating progesterone concentrations in beef heifers. (2012)

Abstract This study examined the effect of a single administration of human chorionic gonadotrophin (hCG) on Day 1 to 4 after oestrus on corpus luteum (CL) development and circulating progesterone (P4). Oestrus-synchronized heifers (n=43) were administered a single intramuscular injection of saline on Day 1 (control) or 3000IU hCG on Day 1, 2, 3 or 4 after oestrus. Administration of hCG on Day 1 had no effect on CL area, on Day 2 increased CL area from Day 6 to 12 (P<0.05), on Day 3 increased CL area from Day 9 to 11, while on Day 4 increased CL size on Days 9 and 10 (P<0.05). Administration of hCG on Day 4 induced the formation of an accessory CL in 89% of heifers, resulting in a significant increase in total luteal tissue area on the ovaries compared with all other groups. Consistent with the effects on the CL, hCG on Day 1 did not affect P4 concentrations, on Day 2 significantly increased P4 compared with the control from Day 6 to 11 (P<0.05), on Day 3 resulted in a non-significant increase in P4 while hCG on Day 4 increased P4 from Day 8 to 13 compared with the control (P<0.05). In conclusion, administration of hCG as early as Day 2 after oestrus results in increased P4 in circulation from Day 6, which should have beneficial downstream effects in terms of uterine receptivity and conceptus elongation.
Collections Ireland -> University College Dublin -> PubMed

Full list of authors on original publication

D Rizos, P. Lonergan, A K Kelly, C de Frutos, L O'Hara, P. Duffy, V Maillo

Experts in our system

1
D Rizos
University College Dublin
Total Publications: 42
 
2
P. Lonergan
University College Dublin
Total Publications: 190
 
3
Alan K Kelly
Teagasc
Total Publications: 83
 
4
P. Duffy
University College Dublin
Total Publications: 42
 
5
V Maillo
University College Dublin
Total Publications: 8