|Farmer, C - AG AND AGRI-FOOD CANADA|
|Petit, H - AG AND AGRI-FOOD CANADA|
Submitted to: Joint Meeting of the ADSA, AMSA, ASAS and PSA
Publication Type: Abstract Only
Publication Acceptance Date: March 19, 2007
Publication Date: July 1, 2007
Citation: Farmer, C., Petit, H.V., Capuco, A.V. 2007. Effects of dietary supplementation with flax during prepuberty on mammary development and circulating prolactin and estradiol concentrations . Joint Meeting of the ADSA, AMSA, ASAS and PSA. Technical Abstract: The possible role of dietary flax on mammary development of prepubertal gilts was investigated. Fifty-seven gilts were fed one of four diets from 88 d of age until slaughter (day 212 ± 1). Diets were: standard, CTL (n=14); 10% flaxseed supplementation, FS (n=13); 6.5% flaxseed meal supplementation, FSM (n=15); and 3.5% flaxseed oil supplementation, FSO (n=15). All diets were isonitrogenous, isolipidic and isocaloric. Jugular blood samples were obtained on days 78 and 210 and assayed for prolactin and estradiol. 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 fatty acid profiles in extraparenchymal tissue were evaluated. Dietary flax increased (P < 0.001) the concentrations of polyunsaturated fatty acids (PUFA) and decreased those of saturated (SFA, P < 0.01) and monounsaturated (MUFA, P < 0.001) fatty acids in mammary extraparenchymal tissue. This was largely due to the inclusion of FS or FSO P < 0.01), but not FSM. Circulating concentrations of prolactin and estradiol were unaltered by treatments (P > 0.1). Dry matter content of parenchymal tissue was the only mammary compositional value affected, showing an increase with flax addition (P < 0.05). Diet did not alter (P > 0.1) BrdU labelling index or estrogen receptor localization. Within mammary parenchyma, estrogen receptors were present in epithelial cells but not adipocytes, a novel demonstration of potential estrogen targets in gilt mammary gland. Dietary supplementation with flax as seed, meal or oil, brought about expected changes in fatty acid profile in mammary extraparenchymal tissue but neither the alteration in fatty acid profile nor the presence of lignans had beneficial effects on hormone concentrations or mammary development.