Relationships between insulin-like growth factor-I, milk yield, body condition score, and postpartum luteal activity in high-producing dairy cows

Abstract

The relations between body condition score (BCS), milk yield, serum insulin-like growth factor-I (IGF-I) profile, and luteal activity were investigated in postpartum dairy cows. Seventy-one healthy high-producing multiparous Holstein cows were subjected to transrectal ultrasound scanning twice weekly from the first to the eighth week postpartum. Blood samples were collected twice weekly to measure serum progesterone (P4) and every 2 weeks to detect serum IGF-I concentrations. BCS was monitored weekly after calving. Cows with serum P4 concentrations ≥1 ng/ml on at least two consecutive samplings were considered to have commenced luteal activity. Commencement of luteal activity (C-LA) was observed earlier than 45 days postpartum in 71.8% of cows while 28.2% showed C-LA later than 45 days. Prolonged luteal phase was the most common abnormal pattern of luteal activity observed. Cows with a C-LA earlier than 45 days postpartum had higher (P ≤ 0.05) mean serum concentrations of IGF-I than those with later C-LA. In addition, cows which showed C-LA earlier than 45 days postpartum had more optimal productive indices including shorter calving to conception interval and calving to first service interval (P ≤ 0.05), and fewer services per conception (P = 0.07). C-LA was significantly later in cows that lost more than 0.5 BCS units within 3 weeks postpartum than in those that lost less than 0.5 units BCS during the same interval (P = 0.02). We conclude that high-producing dairy cows with higher postpartum serum IGF-I concentrations have earlier commencement and normal luteal activity, and better reproductive performance. Severity and duration of BCS loss adversely affect commencement of luteal activity.

Upgrading local cattle in tropical west Africa: Metabolic hormone concentrations during the post-partum period in Sanga and Friesian–Sanga crossbred cows

“…This has been demonstrated in beef as well as dairy cows (Beam and Butler, 1997;Roberts et al, 1997;Taylor et al, 2003;Kawashima et al, 2007;Obese et al, 2011;Tamadon et al, 2011;Samadi et al, 2013). Circulating IGF-I stimulates ovarian function by acting synergistically with gonadotrophins to promote follicular growth, differentiation and steroidogenesis of the ovarian cells (reviews: Lucy, 2000;Chagas et al, 2007;Scaramuzzi et al, 2011;Crowe et al, 2014).…”

A polymorphism in the insulin-like growth factor 1 gene is associated with postpartum resumption of ovarian cyclicity in Holstein-Friesian cows under grazing conditions

“…Potential mechanisms for an association between the SNP IGF-1 / Sna BI and the traits of interest may lie in its location in the promoter region of the IGF-1 gene and its possible influence on transcription factor binding sites and on gene expression [28,41,42]. Higher IGF-1 blood levels have been found in cows exhibiting shorter CLA intervals [13,43]. Association studies between the SNP IGF-1 / Sna BI and plasma IGF-1 concentration in cattle are contradictory.…”

Blood metabolite concentrations and postpartum resumption of ovarian cyclicity in Sanga cows

“…Plasma progesterone concentration was measured weekly from weeks 1 to 13 using a progesterone ELISA kit (Gesellschaft für Biochemica und Diagnostica mbH, Wiesbaden, Germany). The cows were classified as having resumed ovarian cyclicity when a plasma progesterone concentration of ≥1 ng/mL was recorded for two consecutive weekly samples (Tamadon et al, 2011). Based on this parameter, cows were classified as early cycling (resumed cyclicity ≤45 days postpartum; n = 6), late cycling (resumed cyclicity 46 -90 days postpartum; n = 5) or non-cycling (no resumption by 90 days postpartum; n = 5).…”