“…This is in keeping with the proposed mechanism of IGF-I in suppressing the secretion of insulin (Kawai et al 1990; Van Schravendijk, Heylen, Van der Brande & Pipeleers, 1990). It is of interest that mammary function was not compromised by the diminished concentrations of insulin, supporting ear¬ lier data suggesting that the mammary gland of rumi¬ nants is relatively insensitive to changes in insulin (Hove, I91c\a,b;Laarveld, Christensen & Brockman, 1981;Laarveld, Chaplin & Brockman, 1985;Leenanuruska, Niumsup & McDowell, 1988;Vernon, Faulkner, Hay et al 1990). Frequent milking on the day before infusion of IGF-I also attenuated the MBF response, but this effect was not completely abolished.…”