Factors Affecting Insulin-Like Growth Factor-I Concentration in Bovine Milk

Abstract

To establish the naturally occurring range of insulin-like growth factor-I concentrations in bovine milk, samples from individual cows (n = 409) managed on five Missouri dairy herds were assayed. Parity, stage of lactation, and farm affected milk insulin-like growth factor-I concentration. Milk insulin-like growth factor-I concentration was higher in early lactation than mid and late lactation with concentrations in multiparous cows exceeding those in primiparous cows. Insulin-like growth factor-I concentration was negatively correlated to milk production the day of sample collection (r = -.15) and not correlated to predicted 305-d milk yields. Unprocessed bulk tank milk samples (n = 100) from a commercial processing plant had a mean concentration of insulin-like growth factor-I in milk of 4.32 ng/ml with a range of 1.27 to 8.10 ng/ml. This distribution was similar to the range detected in samples from individual cows, but values were lower than those reported for human milk. Concentration of insulin-like growth factor-I in milk was not altered by pasteurization (at 79 degrees C for 45 s). However, insulin-like growth factor-I was undetectable in milk heated to temperatures (121 degrees C for 5 min) required for infant formula preparation or in commercially available infant formula. These data indicated that insulin-like growth factor-I is a normal but quantitatively variable component of bovine milk that is not destroyed by pasteurization but is undetectable in infant formula. Concentration of insulin-like growth factor-I in bovine milk is lower than concentrations reported for human milk yet similar to those reported for human saliva.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of Bovine Somatotropin on Neutrophil Functions and Clinical Symptoms During Streptococcus uberis Mastitis

“…The concentration of IGF-I in milk has also been reported to increase after bST injection (9,56). According to Prosser et al (41), this IGF-I originates from the circulation, rather than being locally synthesized de novo by mammary epithelial cells ( 6 ) .…”

Composition and properties of bovine colostrum: a review

“…In general, the concentrations of growth factors in colostrum are highest during the initial hours post-partum and decline significantly in a time-dependant manner (Collier et al 1991;Ginjala and Pakkanen 1998;Bastian et al 2001). The most abundant growth factors in colostrum are IGF-1 and IGF-II (Marnila and Korohnen 2002).…”

“…The main growth factors in colostrum and milk are epidermal growth factor (EGF) (Yagi et al 1986;Iacopetta et al 1992), betacellulin (BTC) (Bastian et al 2001), insulin-like growth factor I (IGF-I) (Collier et al 1991), IGF-II (Schams 1994), transforming growth factor-β1 (TGF-β1) (Ginjala and Pakkanen 1998), TGF-β2 (Cox and Burk 1991), fibroblast growth factor 1 and 2 (FGF1 and FGF2) and platelet-derived growth factor (PGDF) (Belford et al 1997).…”

Intestinal effects of milkborne growth factors in neonates of agricultural importance.

“…Within a species, IGF-I and IGF-II concentrations in milk are influenced by breed (Simmen et al, 1990b;Baumrucker and Blum, 1993), parity (Campbell and Baumrucker, 1989;Collier et al, 1991), and stage of lactation (Collier et al, 1991). Milk IGF-I concentration Prosser et al, 1991b), but not IGF-II or des-IGF-I (Shimamoto et al, 1992), is increased by bovine somatotropin (bST) treatment.…”