Peripartal progesterone and prolactin have little effect on the rapid transport of immunoglobulin G into colostrum of dairy cows

Abstract

Colostrum formation and lactogenesis in the mammary gland and the timing of parturition are regulated by endocrine signals. Changes in progesterone (P4) and prolactin (PRL) are considered key events that inhibit colostrum formation, trigger parturition, and signal the onset of lactation. The goal of our study was to determine if colostrum yield and composition and immunoglobulin transfer are affected by prepartum milking relative to the decrease in P4, peak of PRL, or occurrence of parturition. Twenty-three multiparous cows were randomly assigned to 1 of 2 groups: (1) control with first milking at 4 h postcalving (CON, n = 11), and (2) treatment group with first milking approximately 1 d before calving and second milking at 4 h after parturition (APM, n = 12). Colostrum yields were recorded and proportional samples were analyzed for immunoglobulin G (IgG) concentration. Blood plasma samples for the analyses of P4 and PRL were collected 3 times daily at 8-h intervals for 4 d prepartum and again taken at 4 h after parturition. Total colostrum mass of APM cows was higher than that of CON cows. Immunoglobulin G concentration and protein content did not differ between antepartum milking in APM cows and postpartum milking in CON cows. Colostrum IgG concentration and protein content in APM cows at the postpartum milking were lower compared with the IgG concentration established at the prepartum (APM) and postpartum milkings of CON cows. Immunoglobulin G mass did not differ in first and second colostrum collection in APM cows but was lower compared with that of CON cows. The sum of IgG mass in APM cows (prepartum + postpartum collections) did not differ from that of CON cows. Lactose and fat in milk (concentration and mass) increased from first to second milking in APM cows. Total mass of lactose and fat in APM cows (prepartum + postpartum collections) was greater compared with that of CON cows. The finding that the time of milking relative to parturition, P4 decrease, and PRL peak slightly affected yield and quality of colostrum emphasizes the complex interactions of numerous endocrine and morphological changes occurring during colostrogenesis and lactogenesis in dairy cows. The considerably rapid transfer of immunoglobulins into colostrum of prepartum-milked cows within a few hours leads to the hypothesis that the transfer of IgG can be very fast and-contrary to earlier findings-persist at least until parturition.

Invited review: Metabolic challenges and adaptation during different functional stages of the mammary gland in dairy cows: Perspectives for sustainable milk production

“…Furthermore, precocial animals such as bovines require milk that is rapidly digestible and frequently available immediately after birth (Hayssen, 1993;Skibiel et al, 2013). Compared with other species, endocrine changes in dairy cows, in particular the decrease in progesterone and peaking concentrations of prolactin and glucocorticoids, occur before the end of term and enable the onset of copious milk production directly at parturition (Figure 2; Hoffmann et al, 1973;Gross et al, 2014a). Thus, milk is immediately available for the newborn calf.…”

“…Elevated prolactin concentrations before parturition trigger the closure of the blood-milk barrier and thus gradually terminate the further transfer of blood-derived proteins such as IgG. Graphs are adapted from Gross et al (2014a) and Wall et al (2015). tein) is higher in superior colostrum.…”

Short communication: Mammary gland tight junction permeability after parturition is greater in dairy cows with elevated circulating serotonin concentrations

“…Immunoglobulins are an essential bioactive component of colostrum, as they provide passive immunization for the ruminant offspring. The transfer of maternal IgG into colostrum is maintained for at least a few hours after parturition and appears to happen in a manner widely independent of changes in progesterone and prolactin (Gross et al, 2014;Baumrucker et al, 2016). Furthermore, the transport of IgG 1 into colostrum occurs primarily via transcytosis, whereas IgG 2 is supposed to pass paracellularly Wall et al, 2015).…”

Review: nutritional and endocrine control of colostrogenesis in swine

“…This is somewhat different from what occurs in dairy cows, with IgG1 transfer beginning several weeks before parturition, peaking a week prepartum and ceasing abruptly before calving (Barrington et al, 2001). Nevertheless, recent findings suggest that the transfer of IgG in dairy cows can persist at least until parturition (Gross et al, 2014).…”