Relationship between Days to Postpartum First Ovulation and Days to Reaching Steady Range of Metabolite Concentrations in Dairy Cows

Abstract

Abstract. Transitional multiparous dairy cows were used to estimate the relationships between the interval from parturition to the first ovulation (1st-OV), and the interval from parturition to the first day when the plasma metabolite concentration reached the steady range (within two standard deviations from the mean value for the post-ovulational 2 weeks). Blood samples were collected from 13 Holstein dairy cows 4 times every week from 14 days prepartum to about 60 days postpartum in order to analyze plasma concentrations of progesterone and the following eight metabolites: glucose, ketone bodies, free fatty acids (FFA), urea nitrogen (UN), free cholesterol, cholesterol ester, glutamic-oxaloacetic transaminase (GOT), and glutamic-pyruvic transaminase (GPT). The interval to 1st-OV averaged 25.6 ± 8.7 days, and correlated respectively with the intervals to the days when plasma concentrations of almost all the metabolites, except GPT and UN, reached the steady range. We concluded that the interval to the 1st-OV of dairy cows is closely related to the interval to the steady range of metabolites concerned with the energy status, but not protein intake. Additionally, the interval to the 1st-OV also correlated significantly with the mean concentration of free cholesterol before the 1st-OV. Key words: Nutritional status, Postpartum first ovulation, Periparturitional dairy cow, Steroidogenesis, Transition period (J. Reprod. Dev. 45: [331][332][333][334][335][336] 1999) P ostpartum first ovulation (1st-OV) is an indica tor for resumption of reproductive function in cows. Early studies [1,2] revealed that there is a linear correlation between the interval from parturition to the 1st-OV, and the interval from parturition to the beginning of the energy balance to recovery (energy balance nadir) in dairy cows. Butler et al. [1] reported that 1st-OV occurred approximately 10 days after the day of the energy balance nadir. Furthermore, Zurek et al. [2] reported that the 1st-OV occurred approximately 15.4 ± 1.2 days after the energy balance nadir, and that the interval to the 1st-OV correlates with neither the mean energy balance before the first ovulation nor the energy balance at the nadir. Therefore, the number of days before energy balance nadir is an important factor for 1st-OV in dairy cows.Plasma metabolite (and enzymes) concentrations reflect the energy status [glucose, free fatty acids (FFA) and ketone bodies], protein intake [urea nitrogen (UN)], hepatic function [glutamicoxaloacetic transaminase (GOT) and glutamicpyruvic transaminase (GPT)], or precursor availability for steroidogenesis (free cholesterol and cholesteryl ester) in dairy cows [3]. Therefore,

A New Perspective on Management of Reproduction in Dairy Cows: the Need for Detailed Metabolic Information, an Improved Selection Index and Extended Lactation

“…Other studies [8,14,15] also support our contention that more than one hormone and energy substrate are responsible for the linkage between nutritional status and reproductive function. Thus, we should image multifactorial model, for example, Liebig's Law of the Minimum.…”

Plasma thiobarbituric acid reactive substances, vitamin A and vitamin E levels and resumption of postpartum ovarian activity in dairy cows

“…Because the first ovulation at early postpartum does not guarantee that the subsequent fertilization, implantation, embryo development, growth of fetus and so on, will work out, the early postpartum ovulation does not lead directly to the improvement of cow reproductive performance. However, there have been several reports that the first postpartum ovulation is considered to be one of the indicators for recovery of reproductive function in cows (Butler et al 1981;Stevenson & Call 1982;Zurek et al 1995;Kadokawa & Yamada 1999).…”