Postpartum reproductive function: association with energy, metabolic and endocrine status in high yielding dairy cows

• Published in: Theriogenology Vol. 59; no. 8; pp. 1707 - 1723
• Main Authors: Reist, Martin, Erdin, Daniel K, von Euw, Daniel, Tschümperlin, Kaspar M, Leuenberger, Hans, Hammon, Harald M, Morel, Claudine, Philipona, Chantal, Zbinden, Yolande, Künzi, Niklaus, Blum, Jürg W
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.04.2003
• Subjects: Animals; Body Weight; Cattle - physiology; Cattle Diseases - diagnosis; Dairy cows; Days open; Diet; Energy balance; Energy Metabolism; Female; Fertilization; First ovulation; Hormones - blood; Lactation; Logistic Models; Metabolic status; Milk - chemistry; Ovulation; Postpartum Period; Pregnancy; Reproduction - physiology; Time Factors; Dairy cows; Energy balance; Metabolic status; First ovulation; Days open
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/S0093-691X(02)01238-4

This study evaluated the effect of metabolic, endocrine and energy status on onset of ovarian cycle, days open (DO), and conception at first service in 90 multiparous Holstein cows, housed at a research farm. Dry matter intake, milk yield and body weight were measured daily from Week 2 antepartum (a.p.) to Week 20 postpartum (p.p.). Milk composition was determined four times per week and milk acetone was measured weekly. Blood samples for the determination of glucose, non-esterified fatty acids, cholesterol, creatinine, albumin, urea, β-hydroxybutyrate, leptin, insulin, insulin-like growth factor-1, growth hormone, 3,5,3′-triiodothyronine (T3), and thyroxine (T4) were taken 2 weeks a.p., in Weeks 1–16, and 20 p.p. between 7:30 and 9:00h. The onset of ovarian cycle was specified by weekly gynecological examination and by skim milk progesterone determination by radioimmunoassay (twice per week). Energy balance (EB) traits were calculated and expressed as accumulated negative EB from calving to EB equilibrium, EB nadir (EBN), rate of EB recovery after EBN (EBR), and time from calving to EBN and to EB equilibrium, respectively. The onset of ovarian cycle p.p. was not related to EB. However, a low degree of EBN and a fast EBR were associated with fewer DO, and EB at first service was positively related to conception. High plasma levels of T3 and T4 p.p. were associated with an early start of ovarian cycle, and high concentrations of glucose and cholesterol with a short calving to conception interval. Conception at first service was positively related to EB at first service and progesterone concentration 10–13 days after first service. In conclusion, thyroid hormones may play an important role in resumption of ovarian cyclicity p.p., and a good energy status enhances the chance of conception at first service and shortens DO.