Feeding soybean meal increases the blood level of isoflavones and reduces the steroidogenic capacity in bovine corpora lutea, without affecting peripheral progesterone concentrations.
Thirty-three Holstein-Friesian cows were followed from 14 days pre partum until the fourth ovulation post partum. Housing conditions and basic ration were identical for all animals. Concentrates were individually supplemented according to the daily milk production level, using two different types of protein rich concentrates: soybean meal and rapeseed meal. Soybean and rapeseed meal are known to be respectively high and low in isoflavones. Cows were randomly divided into three groups and blocked for parity. Group I (n=11) was supplemented with soybean meal and acted as control group. Groups II (n=11) and III (n=11) were respectively supplemented with soybean and rapeseed meal and were subjected to a biopsy sampling of the corpus luteum at day 9 of the first three postpartal estrous cycles. Soybean meal supplementation to lactating dairy cows (1.72 kg on average) induced an increase in the blood concentration of equol, dihydrodaidzein, o-desmethylangolensin in both soy groups and resulted in a reduced area occupied by steroidogenic (P=0.012) and endothelial cells (P=0.0007) in the luteal biopsies. Blood concentrations of equol and glycitein were negatively correlated with the areas occupied by steroidogenic (r=-0.410 with P=0.0002, respectively r=-0.351 with P=0.008) and endothelial cells (r=-0.337 with P=0.01, respectively r=-0.233 with P=0.085) in the 3 first estrous cycles. The latter however did not affect the diestrous peripheral blood progesterone concentration.
Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: s.cools@ugent.be.
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Cools
Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: wim.vandenbroeck@ugent.be.
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Van den Broeck
Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: lynn.vanhaecke@ugent.be.
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Vanhaecke
Laboratory of Pharmacognosy and Phytochemistry, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, 9000 Ghent, Belgium. Electronic address: arne.heyerick@ugent.be.
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Heyerick
Department of Veterinary Sciences, Campus Drie Eiken, Antwerp University, Universiteitsplein 1, 2610 Wilrijk, Belgium. Electronic address: philippe.bossaert@ua.ac.be.
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Bossaert
Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: miel.hostens@ugent.be.
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Hostens
Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: geert.opsomer@ugent.be.
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Opsomer
D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle; D003338:Corpus Luteum / Q000378:metabolism*; D005260:Female; D012739:Gonadal Steroid Hormones / Q000096:biosynthesis*; D007529:Isoflavones / Q000097:blood*; D007774:Lactation; D008892:Milk / Q000378:metabolism; D049590:Postpartum Period / Q000097:blood / Q000378:metabolism; D011247:Pregnancy; D011374:Progesterone / Q000097:blood*; D013025:Glycine max
D012739:Gonadal Steroid Hormones; D007529:Isoflavones; D011374:Progesterone
Corpus luteum; Dairy cow; Isoflavones; Progesterone; Soy bean meal