Associations between energy metabolism, LH pulsatility and first ovulation in early lactating cows.
This study was designed to elucidate associations between energy metabolism and LH pulsatility characteristics in early lactation, and days to first ovulation, in order to explain the relationship between energy balance and fertility observed in epidemiological studies. To this end, 10 multiparous HF cows were monitored during lactation, after the application of two different feeding strategies during the dry period. Days to first ovulation was assessed using blood progesterone measurements and LH pulsatility was measured in 8-h windows in the third week postpartum. The association between depth of negative energy balance and days to ovulation was confirmed. However, this study does not support the idea that LH pulsatility characteristics in early lactation are predictive for the interval between parturition and first ovulation.
Jorritsma
R
R
Faculty of Veterinary Medicine, Utrecht University, The Netherlands. r.jorritsma@vet.uu.nl
Langendijk
P
P
Kruip
T A M
TA
Wensing
T H
TH
Noordhuizen
J P T M
JP
D020155:3-Hydroxybutyric Acid / Q000097:blood; D000818:Animals; D001786:Blood Glucose; D002417:Cattle / Q000378:metabolism*; D004734:Energy Metabolism; D005260:Female; D007328:Insulin / Q000097:blood; D007774:Lactation / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000097:blood*; D010060:Ovulation; D049590:Postpartum Period; D011247:Pregnancy
D001786:Blood Glucose; D007328:Insulin; D007986:Luteinizing Hormone; D020155:3-Hydroxybutyric Acid