Submitted to: American Dairy Science Association Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/12/2008
Publication Date: 7/1/2008
Citation: Farmer, C., Gilani, S., Palin, M.F., Weiler, H., Vignola, M., Choudhary, R.K., Capuco, A.V. 2008. FEEDING GENISTEIN TO PREPUBERTAL GILTS STIMULATES THEIR MAMMARY DEVELOPMENT. [abstract]. American Dairy Science Association Abstracts. Interpretive Summary:
Technical Abstract: The possible role of dietary genistein on mammary development of prepubertal gilts was investigated. Forty-five gilts were fed one of three diets from 90 d of age until slaughter (day 183 ± 1). Diets were: without soya (CTL0, n=15); soya-based commercial (CTLS, n=15); and soya-based commercial with 2.3 g/d of genistein (GEN, n=15). All diets were isonitrogenous and isocaloric. Jugular blood samples were obtained on days 89 and 183 to determine concentrations of genistein, prolactin, estradiol, IGF-I and cross-linked N-telopeptide of type I collagen (NTx, day 183 only). At slaughter, mammary glands were excised, parenchymal and extraparenchymal tissues were dissected and composition of parenchymal tissue was determined. Histochemical analyses of mammary parenchyma were performed and mRNA level of specific genes determined. Dietary genistein increased parenchymal protein (P < 0.05) while decreasing dry matter (P < 0.05) and tending to lower fat content compared to the CTLS, but not the CTL0, diet. There was more parenchymal DNA (1.26 vs. 0.92 mg/g, P < 0.05) in GEN than CTLS gilts. Circulating concentrations of hormones or NTx were not affected by GEN (P > 0.1) but concentrations of genistein were greater (P < 0.0001) in GEN than CTLS gilts. Percent ERa-positive epithelial cells was lower (P < 0.05) in GEN than CTLS gilts whereas BrdU labelling index was unaltered (P > 0.1). Transcript levels for ERa, ERß, IGF-I, EGF, EGFR and TGFa were not altered by treatments (P > 0.1). Feeding dietary genistein to prepubertal gilts led to hyperplasia of mammary parenchymal tissue.