Research-Article| Volume 72, ISSUE 3, P784-804, March 1989

Recent Developments in the Roles of Vitamins and Minerals in Reproduction

      This paper is only available as a PDF. To read, Please Download here.


      Vitamins and minerals affect reproductive function. Vitamin A deficiency has long been known to affect reproductive function in cattle. More recently, a role has been proposed for the vitamin A percursor, β-carotene, in reproductive efficiency. Dietary supplementation with vitamin E and selenium may reduce the incidence of retained placenta, but these nutrients may also affect reproductive function in other ways. Calcium and phosphorus deficiencies affect reproduction in cattle, and vitamin D may directly affect reproductive function in addition to its role in calcium and phosphorus metabolism. Dietary manipulation of a number of other vitamins and minerals also influences reproductive function. However, the specific roles of nutrients in reproductive tissues are not well-defined in dairy cattle, and nutrient requirements for optimal reproductive efficiency in modern dairy cattle deserve careful reevaluation. This review provides a background of the effect of vitamins and minerals on reproduction and it attempts to provide a basis for further investigation of specific mechanisms by which reproductive function is affected. The interface between nutritional science and reproductive physiology provides considerable potential for optimizing reproductive efficiency in dairy cattle.


        • Afiefy M.M.
        • Zaki K.
        • Abul-Fadle W.
        • Ayoub L.A.
        • Soliman F.A.
        Iodine metabolism in relation to reproductive status in cows.
        Zentralbl. Veterinarmed. 1970; 17: 62
        • Ahlswede L.
        • Lotthammer K.H.
        Unterschungen uber eine spezifische. Vitamin A-unabhangige wirkung des β-carotins auf die fertilitat des rindes. 5. Mitt. : Organunterschungen-Gewichts and Gehaltsbestimmungen.
        Dtsch. Tierarztl. Wochenschr. 1978; 85: 7
        • Ahluwalia B.
        • Devi A.
        • Clark J.F.J.
        Enhancement with zinc in the seminiferous tubules of rat testes.
        Fed. Proc. 1973; 34 (Abstr.): 1
        • Akordor F.Y.
        • Stone J.B.
        • Walton J.S.
        • Leslie K.E.
        • Buchanan-Smith J.G.
        Reproductive performance of lactating Holstein cows fed supplemental β-carotene.
        J. Dairy Sci. 1986; 69: 2173
        • Alderman G.
        Mineral nutrition and reproduction in cattle.
        Vet. Rec. 1963; 75: 1015
        • Allcroft R.
        • Parker W.H.
        Hypocupraemia in dairy cows.
        Br. J. Nutr. 1949; 3: 204
        • Allcroft R.
        • Scarnell J.
        • Hignett S.L.
        A preliminary report on hypothyroidism in cattle and its possible relationship with reproductive disorders.
        Vet. Rec. 1954; 66: 367
        • Ammerman C.B.
        • Miller S.M.
        Selenium in ruminant nutrition: a review.
        J. Dairy Sci. 1975; 58: 1561
        • Anke M.
        • Groppel B.
        Manganese deficiency and radioisotope studies on manganese metabolism.
        in: Mills C.F. Trace element metabolism in animals. E. and S. Livingstone, Edinburgh1970: 133
        • Anke M.
        • Groppel B.
        • Reissig W.
        • Ludke H.
        • Grun M.
        • Dittrich G.
        Manganese deficiency in ruminants. (3) Manganese deficiency stimulated reproductive-, skeletal-, and nervous-disturbances in female ruminants and their off-spring.
        Arch. Tierernahr. 1973; 23: 197
        • Annenkov B.N.
        Mineral feeding of cattle.
        in: Georgievskii V.I. Annenkov B.N. Samok-hin V.T. Mineral nutrition of animals. Butterworths, London1981: 285
        • Apagar J.
        Zinc and reproduction.
        Ann. Rev. Nutr. 1985; 5: 43
        • Arthur J.R.
        • Boyne R.
        Superoxide dismutase and glutathione peroxidase activities in neutrophils from selenium deficient and copper deficient cattle.
        Life Sci. 1985; 36: 1569
        • Ascarelli I.
        • Edelman Z.
        • Rosenberg M.
        • Folman Y.
        Effect of dietary carotene on fertility of high-yielding dairy cows.
        Anim. Prod. 1985; 40: 195
        • Ashes J.R.
        • Burley R.W.
        • Davenport J.B.
        • Sidhu G.S.
        Effects of dietary supplements of protected lipids on the concentration and transport of β-carotene and cholesterol in bovine blood and milk: unusual chromatographic behaviour of the high density lipoprotein with high levels of β-carotene.
        J. Dairy Res. 1982; 49: 39
        • Ashes J.R.
        • Burley R.W.
        • Sidhu G.S.
        • Sleigh R.W.
        Effect of particle size and lipid composition of bovine blood high density lipoprotein on its function as a carrier of β-carotene.
        Biochim. Biophys. Acta. 1984; 797: 171
        • Austern B.M.
        • Gawienowski A.M.
        The isolation of retinal from the bovine corpus luteum.
        J. Reprod. Fertil. 1969; 19: 203
        • Baccetti B.
        • Pallini V.
        • Burrini A.G.
        The accessory fibers of the sperm tail. 1. Structure and chemical composition of the bull “coarse fibers”.
        J. Submicrosc. Cytol. 1973; 5: 237
        • Barnea A.
        • Cho G.
        • Colombani-Vidal M.
        A role for extracellular copper in modulating prostaglindin E2 (PGE2) action: facilitation of PGE2 stimulation of the release of gonadotropin-releasing hormone (LHRH) from median eminence explants.
        Endocrinology. 1985; 117: 415
        • Bartle J.L.
        • Senger P.L.
        • Hillers J.K.
        Influences of injected selenium in dairy bulls on blood and semen selenium, glutathione peroxidase and seminal quality.
        Biol. Reprod. 1980; 23: 1007
        • Benedict C.R.
        • Kett J.
        • Porter J.W.
        Properties of fannesyl pyrophosphate synthetase of pig liver.
        Arch. Biochem. Biophys. 1965; 110: 611
        • Bentley O.G.
        • Phillips P.M.
        The effect of low manganese rations upon dairy cattle.
        J. Dairy Sci. 1951; 34: 396
        • Bindas E.M.
        • Gwazdauskas F.C.
        • Aiello R.J.
        • Herbein J.H.
        • McGilliard M.L.
        • Polan C.E.
        Reproductive and metabolic characteristics of dairy cattle supplemented with β-carotene.
        J. Dairy Sci. 1984; 67: 1249
        • Bindas E.M.
        • Gwazdauskas F.C.
        • McGilliard M.L.
        • Polan C.E.
        Progesterone responses to human chorionic gonadotropin in dairy cattle supplemented with β-carotene.
        J. Dairy Sci. 1984; 67: 2978
        • Blakemore F.
        • Venn J.A.J.
        Conditions associated with hypocupraemia in bovines in East Anglia.
        Vet. Rec. 1950; 62: 756
        • Bourne F.
        Manganese: its relationship to infertility in the bovine.
        Feed Forum. 1967; 2: 33
        • Bratton R.W.
        • Salisbury G.W.
        • Tanabe T.
        • Branton C.
        • Mercier E.
        • Loosli J.K.
        Breeding behavior, spermatogenesis, and semen production of mature dairy bulls fed rations low in carotene.
        J. Dairy Sci. 1948; 31: 779
        • Bremel D.H.
        • Hemken R.W.
        • Heersche Jr., G.
        • Edgerton L.A.
        • Olds D.
        Effects of β-carotene on metabolic and reproductive parameters in lactating dairy cows.
        J. Dairy Sci. 1982; 65 (Abstr.): 178
        • Bremner I.
        Absorption, transport and distribution of copper.
        in: Biological roles of copper. Ciba Found. Symp. 79. Excerpta Medica, Amsterdam, Neth1980: 23
        • Brent B.E.
        • Bartley E.E.
        Thiamine and niacin in the rumen.
        J. Anim. Sci. 1984; 59: 813
        • Buchanan-Smith J.G.
        • Nelson E.C.
        • Osburn B.I.
        • Wells M.E.
        • Tillman A.D.
        Effect of vitamin E and selenium deficiencies in sheep fed a purified diet during growth and reproduction.
        J. Anim. Sci. 1969; 29: 808
        • Buck E.L.
        • Schmitz J.A.
        • Swanson L.V.
        Incorporation of Se into endocrine glands and reproductive tissues of the prepartum ewe and fetus.
        in: Spallholz J.E. Martin J.L. Ganther H.E. Selenium in biology and medicine. AVI Publ. Co., Inc., Westport, CT1981: 514
        • Burton G.W.
        • Ingold K.U.
        β-carotene: an unusual type of lipid antioxidant.
        Science. 1984; 224: 569
        • Byers J.H.
        • Jones I.R.
        • Bone J.F.
        Carotene in the ration of dairy cattle. II. The influence of suboptimal levels of carotene intake upon the microscopic aspect of selected organs.
        J. Dairy Sci. 1956; 39: 1556
        • Calvin H.I.
        • Hwang F.H.
        • Wohlrab H.
        Localization of zinc in a dense fibre-connecting piece fraction of rat sperm tails analogous chemically to hair keratin.
        Biol. Reprod. 1975; 13: 228
        • Calvin H.I.
        • Yu C.C.
        • Bedford J.M.
        Effects of epididymal maturation, zinc (II) and copper (II) on the reactive sulphydryl content of structural elements in rat spermatozoa.
        Exp. Cell Res. 1973; 81: 333
        • Cass A.E.G.
        • Hill H.A.O.
        Copper proteins and enzymes.
        in: Biological roles of copper. Ciba Found. Symp. 79. Exerpta Medica, Amsterdam, Neth1980: 71
        • Chalopin H.
        • Mouton M.
        • Ratsimamanga A.R.
        Some interrelations between ascorbic acid and adreno-cortical function.
        World Rev. Nutr. Diet. 1966; 6: 165
        • Chesters J.K.
        Biochemical functions of zinc in animals.
        World Rev. Nutr. Diet. 1978; 32: 135
        • Chew B.P.
        • Holpuch D.M.
        • O’Fallon J.V.
        Vitamin A and β-carotene in bovine and porcine plasma, liver, corpora lutea, and follicular fluid.
        J. Dairy Sci. 1984; 67: 1316
        • Chytil F.
        • Ong D.E.
        Cellular retinoid-binding proteins.
        in: Theretinoids. 2. Academic Press, Inc., New York, NY1984: 89
        • Cooper D.R.
        • Kling O.R.
        • Carpenter M.P.
        Effect of vitamin E deficiency on serum concentration of follicle-stimulating hormone and testosterone during testicular maturation and degeneration.
        Endocrinology. 1987; 120: 83
        • Dahmer M.K.
        • Housley P.R.
        • Pratt W.B.
        Effects of molybdate and endogenous inhibitors on steroid-receptor inactivation, transformation, and translocation.
        Ann. Rev. Physiol. 1984; 46: 67
        • Daniels L.B.
        • Kellogg D.W.
        • Harrison K.F.
        Effect of supplementing dairy cows and heifers with selenium and vitamin E.
        J. Dairy Sci. 1987; 70 (Abstr.): 202
        • Dickson I.
        New approaches to vitamin D.
        Nature. 1987; 325: 18
        • Diplock A.T.
        The role of vitamin E and selenium in the prevention of oxygen-induced tissue damage.
        in: Spallholz J.E. Martin J.L. Ganther H.E. Selenium in biology and medicine. AVI Publ. Co., Inc., West port, CT1981: 303
        • Doisy Jr, E.A.
        Effects of deficiency in manganese upon plasma levels of clotting proteins and cholesterol in man.
        in: Trace elemens in animals. 2. University Park Press, Baltimore, MD1974: 668
        • Ducker M.J.
        • Yarrow N.H.
        • Bloomfield G.A.
        • Edwards-Webb J.D.
        The effect of β-carotene on the fertility of dairy heifers receiving maize silage.
        Anim. Prod. 1984; 39: 9
        • Dyer I.A.
        Implications of manganese deficiency in the etiology of deformed calves.
        Proc. West. Sect. Am. Soc. Anim. Prod. 1961; 12 (LXVII)
        • Eger S.
        • Drori D.
        • Kadoori I.
        • Miller N.
        • Schindler H.
        Effects of selenium and vitamin E on incidence of retained placenta.
        J. Dairy Sci. 1985; 68: 2119
        • Erb R.E.
        • Andrews F.N.
        • Hauge S.M.
        • King W.A.
        Observations on vitamin A deficiency in young dairy bulls.
        J. Dairy Sci. 1947; 30: 687
        • Erdman R.A.
        • Shaver R.D.
        • Vandersall J.H.
        Dietary choline for the lactating cow: possible effects on milk fat synthesis.
        J. Dairy Sci. 1984; 67: 410
        • Fitzgerald J.A.
        • Everett G.A.
        • Apgar J.
        Effect of low zinc intake during pregnancy on plasma prolactin, progesterone, prostaglandin, cortisol and protein concentrations of ewes during the periparturient period.
        Can. J. Anim. Sci. 1986; 66: 643
        • Folman Y.
        • Ascarelli I.
        • Herz Z.
        • Rosenberg M.
        • Davidson M.
        • Halevi A.
        Fertility of dairy heifers given a commercial diet free of β-carotene.
        Br. J. Nutr. 1979; 41: 353
        • Folman Y.
        • Ascarelli I.
        • Kraus D.
        • Barash H.
        Adverse effect of β-carotene in diet on fertility of dairy cows.
        J. Dairy Sci. 1987; 70: 357
        • Ford C.M.
        Some interactions of climate and mineral nutrition on the fertility of cattle in the Midland areas of Great Britain. VII.
        Int. Kongr. Tier. Fort. 1972; 3: 2011
        • Freeman B.A.
        • Crapo J.D.
        Free radicals and tissue injury.
        Lab. Invest. 1982; 47: 412
        • Ganguly J.
        • Rao M.R.S.
        • Murthy S.K.
        • Sarada K.
        Systemic mode of action of vitamin A.
        Vitam. Horm. 1980; 38: 1
        • Gawienowski A.M.
        • Stacewicz-Sapuncakis M.
        • Longley R.
        Biosynthesis of retinal in bovine corpus luteum.
        J. Lipid Res. 1974; 15: 375
        • Georgievskii V.I.
        The Physiological role of microelements.
        in: Georgievskii V.I. Annenkov B.N. Samokhin V.T. Mineral nutrition of animals. Butterworths, London, Engl1981: 171
        • Gerloff B.J.
        • Morrow D.A.
        Effect of nutrition on reproduction in dairy cattle.
        in: Morrow D.A. Current therapy in theriogenology. W. B. Saunders Co., Philadelphia, PA1986: 310
        • Glover J.
        • Kershaw R.C.
        • Large S.
        Control of retinol transport in plasma.
        World Rev. Nutr. Diet. 1978; 31: 21
        • Goodman D.S.
        Plasma retinol-binding protein.
        in: The retinoids. 2. Academic Press, Inc., New York, NY1984: 41
        • Goodman D.S.
        • Blaner W.S.
        Biosynthesis, absorption, and hepatic metabolism of retinol.
        in: The retinoids. 2. Academic Press, Inc., New York, NY1984: 1
        • Gullickson T.W.
        • Palmer L.S.
        • Boyd W.L.
        • Nelson J.W.
        • Olson F.C.
        • Calverley C.E.
        • Boyer P.D.
        Vitamin E in the nutrition of cattle. I. Effect of feeding vitamin E poor rations on reproduction, health, milk production and growth.
        J. Dairy Sci. 1949; 32: 495
        • Gwazdauskas F.C.
        • Bibb T.L.
        • McGilliard M.L.
        • Lineweaver J.A.
        Effect of prepartum selenium-vitamin E injection on time for placenta to pass and on productive functions.
        J. Dairy Sci. 1979; 62: 978
        • Harrison J.H.
        • Conrad H.R.
        Selenium and glutathione peroxidase activity in tissues of the dairy cow after short-term feeding.
        J. Dairy Sci. 1984; 67: 2464
        • Harrison J.H.
        • Hancock D.D.
        • Conrad H.R.
        Vitamin E and selenium for reproduction of the dairy cow.
        J. Dairy Sci. 1984; 67: 123
        • Harrison J.H.
        • Hancock D.D.
        • Pierre St.N.
        • Conrad H.R.
        • Harvey W.R.
        Effect of prepartum selenium treatment on uterine involution in the dairy cow.
        J. Dairy Sci. 1986; 69: 1421
        • Hart G.H.
        • Guilbert H.R.
        Vitamin-A deficiency as related to reproduction in range cattle.
        California Agric. Exp. Stn. Bull. 1933; : 560
        • Hartmans J.
        Manganese experiments with monozygote cattle twins.
        Landwirtsch. Forsch., Sonderholm. 1972; 27: 1
        • Heller J.
        Interactions of plasma retinol-binding protein with its receptor.
        J. Biol. Chem. 1975; 250: 3613
        • Heller J.
        Characterization of bovine plasma retinol-binding protein and evidence for lack of binding between it and other bovine plasma proteins.
        J. Biol. Chem. 1975; 250: 6549
        • Hemken R.W.
        • Bremel D.H.
        Possible role of beta-carotene in improving fertility in dairy cattle.
        J. Dairy Sci. 1982; 65: 1069
        • Hemken R.W.
        • Olds D.
        • Botts R.L.
        • Bull L.S.
        Selenium injection prior to calving on prevention of retained placenta.
        J. Dairy Sci. 1978; 61 (Abstr.): 209
        • Hidiroglou M.
        54Mn uptake by the ovaries and reproductive tract of cycling and anestrous ewes.
        Can. J. Physiol. Pharmacol. 1975; 53: 969
        • Hidiroglou M.
        Trace element deficiencies and fertility in ruminants: a review.
        J. Dairy Sci. 1979; 62: 1195
        • Hidiroglou M.
        • Ho S.K.
        • Ivan M.
        • Shearer D.A.
        Manganese status of pasturing ewes, of pregnant ewes and doe rabbits on low manganese diets and of dairy cows with cystic ovaries.
        Can. J. Comp. Med. 1978; 43: 100
        • Hidiroglou M.
        • Ho S.K.
        • Standish J.F.
        Effects of dietary manganese levels on reproductive performance of ewes and on tissue mineral composition of ewes and day-old lambs.
        Can. J. Anim. Sci. 1978; 58: 35
        • Hidiroglou M.
        • Ivan M.
        • Ho S.K.
        Effect of human chorionic gonadotropin on the transport of manganese and zinc and tissue uptake of radioactivity following subcutaneous administration of tritiated esterone in manganese deficient and non-deficient rabbits.
        Can. J. Comp. Med. 1977; 41: 206
        • Hidiroglou M.
        • Knipfel J.E.
        Zinc in mammalian sperm: a review.
        J. Dairy Sci. 1984; 67: 1147
        • Hidiroglou M.
        • McAllister A.J.
        • Williams C.J.
        Prepartum supplementation of selenium and vitamin E to dairy cows: assessment of selenium status and reproductive performance.
        J. Dairy Sci. 1987; 70: 1281
        • Hidiroglou M.
        • Shearer D.A.
        Concentration of manganese in the tissues of cycling and anestrous ewes.
        Can. J. Comp. Med. 1976; 40: 306
        • Hignett S.L.
        Factors influencing herd fertility in cattle.
        Vet. Rec. 1950; 62: 652
        • Hodgson R.E.
        • Hall S.R.
        • Sweetman W.J.
        • Wiseman H.G.
        • Converse H.T.
        The effect of vitamin A deficiency on reproduction in dairy bulls.
        J. Dairy Sci. 1946; 29: 669
        • Horner J.L.
        • Coppock C.E.
        • Schelling G.T.
        • Lahore J.M.
        • Nave D.H.
        Influence of niacin and whole cottonseed on intake, milk yield and composition, and systemic responses of dairy cows.
        J. Dairy Sci. 1986; 69: 3087
        • Hornsby P.J.
        • Harris S.E.
        • Aldern K.A.
        The role of ascorbic acid in the function of adrenal cortex: studies in adrenocortical cells in culture.
        Endocrinology. 1985; 117: 1264
        • Horst R.L.
        • Reinhardt T.A.
        Vitamin D metabolism in ruminants and its relevance to the periparturient cow.
        J. Dairy Sci. 1983; 66: 661
        • Howes A.D.
        • Dyer I.A.
        Diet and supplemental mineral effects on manganese metabolism in newborn calves.
        J. Anim. Sci. 1971; 32: 141
        • Hunter A.P.
        Some nutritional factors affecting the fertility of dairy cattle.
        N. Z. Vet. J. 1977; 25: 305
        • Hurley L.S.
        • Keen C.L.
        • Lonnerdal B.
        Copper in fetal and neonatal development.
        in: Biological roles of copper. Ciba Found. Symp. 79. Excerpta Medica, Amsterdam, Neth1980: 227
        • Ingraham R.H.
        • Kappel L.C.
        • Morgan E.B.
        • Srikandakumar A.
        Correction of subnormal fertility with copper and magnesium supplementation.
        J. Dairy Sci. 1987; 70: 167
        • Ishak M.A.
        • Larson L.L.
        • Owen F.G.
        • Lowry S.R.
        • Erickson E.D.
        Effects of selenium, vitamins, and ration fiber on placental retention and performance of dairy cattle.
        J. Dairy Sci. 1983; 66: 99
        • Jackson P.S.
        A note on a possible association between plasma β-carotene levels and conception rate in a group of winter-housed dairy cattle.
        Anim. Prod. 1981; 32: 109
        • Janszen F.H.A.
        • Cooke B.A.
        • Van Driel M.J.A.
        • Van Der Molen H.J.
        The effect of calcium ions on testosterone production in Leydig cells from rat testis.
        Biochem. J. 1976; 160: 433
        • Jordan H.A.
        • Smith G.S.
        • Neumann A.L.
        • Zimmerman J.E.
        • Breniman G.W.
        Vitamin A nutrition of beef cattle fed corn silages.
        J. Anim. Sci. 1963; 22: 738
        • Julien W.E.
        • Conrad H.R.
        • Jones J.E.
        • Moxon A.L.
        Selenium and vitamin E and incidence of retained placenta in parturient dairy cows.
        J. Dairy Sci. 1976; 59: 1954
        • Julien W.E.
        • Conrad H.R.
        • Moxon A.L.
        Selenium and vitamin E and incidence of retained placenta in parturient dairy cows. II. Prevention in commercial herds with prepartum treatment.
        J. Dairy Sci. 1976; 59: 1960
        • Juneja H.S.
        • Murthy S.K.
        • Ganguly J.
        The effect of vitamin A deficiency on the biosynthesis of steroid hormones in rats.
        Biochem. J. 1966; 99: 138
        • Kappel L.C.
        • Ingraham R.H.
        • Morgan E.B.
        • Dixon J.M.
        • Zeringue L.
        • Wilson D.
        • Babcock D.K.
        Selenium concentrations in feeds and effects of treating pregnant Holstein cows with selenium and vitamin E on blood selenium values and reproductive performance.
        Am. J. Vet. Res. 1984; 45: 691
        • Kato M.
        • Blaner W.S.
        • Mertz J.R.
        • Das K.
        • Kato K.
        • Goodman D.S.
        Influence of retinoid nutritional status on cellular retinol- and cellular retinoic acid-binding protein concentrations in various rat tissues.
        J. Biol. Chem. 1985; 260: 4832
        • Kellokumpu S.
        • Rajaniemi H.
        Effect of zinc on the uptake of human chorionic gonadotropin (hCG) in rat testis and testosterone response in vivo.
        Biol. Reprod. 1981; 24: 298
        • King J.O.L.
        Nutrition and fertility in dairy cows.
        Vet. Rec. 1971; 89: 320
        • King T.B.
        • Lohman T.G.
        • Smith G.S.
        Evidence of rumeno-reticular losses of vitamin A and carotene.
        J. Anim. Sci. 1962; 21 (Abstr.): 1002
        • Kozicki L.
        • Silva R.G.
        • Barnabe R.C.
        Effects of vitamins A, D3, E, and C on the characteristics of bull semen.
        Zentralbl. Veterin aermed. 1981; 28: 538
        • Kubota M.
        • Ohno J.
        • Shiina Y.
        • Suda T.
        Vitamin D metabolism in pregnant rabbits: differences between the maternal and fetal response to administration of large amounts of vitamin D.
        Endocrinology. 1982; 110: 1950
        • Kuhlman A.H.
        • Gallup W.D.
        Carotene (provitamin A) requirements of dairy cattle for conception.
        J. Dairy Sci. 1942; 25: 688
        • Larson L.L.
        • Wang J.Y.
        • Owen F.G.
        • Meader J.E.
        Effect of beta-carotene supplementation during early lactation on reproduction.
        J. Dairy Sci. 1983; 66 (Abstr.): 240
        • Leathem J.H.
        Nutritional effects on endocrine secretions.
        in: Young W.C. Sex and internal secretions. Williams and Wilkins Co., Baltimore, MD1961: 666
        • Leathern J.H.
        Nutritional effects on hormone production.
        J. Anim. Sci. 1966; : 68
        • Leathern J.H.
        in: The testis. Vol. 3. Influencing factors. Academic Press, New York, NY1970: 193
        • Lee C.N.
        • Schneider D.K.
        • Benin M.E.
        • Fritschel P.R.
        • Jorgensen N.A.
        • Ax R.L.
        Beta carotene: its relationship with progesterone in dairy cows and its concentrations in several feedstuffs.
        J. Dairy Sci. 1985; 68 (Abstr.): 179
        • Lennon H.D.
        • Mixner J.P.
        Relationships between plasma protein-bound iodine and certain measures of reproductive and lactational performance in dairy cattle.
        J. Dairy Sci. 1959; 42: 327
        • Levine M.
        • Morita K.
        Ascorbic acid in endocrine systems.
        Vitam. Horm. 1985; 42: 1
        • Levy F.O.
        • Eikvar L.
        • Jutte N.H.P.M.
        • Hansson V.
        Properties and compartmentalization of the testicular receptor for 1,25-dihydroxy vitamin D3.
        Ann. N. Y. Acad. Sci. 1984; 438: 591
        • Lichtenwalner R.E.
        • Fontenot J.P.
        • Tucker R.E.
        Effect of nitrogen source and nitrate level on vitamin A metabolism.
        J. Anim. Sci. 1969; 29 (Abstr.): 164
        • Lin T.
        Mechanism of action of gonadotropin releasing hormone stimulated steroido genesis. I. The stimulatory effect is calcium dependent and not mediated by cyclic nucleotides.
        J. Androl. 1984; 5: 193
        • Lin T.
        The role of calcium/phospholipid-dependent protein kinase in Leydig cell steroidogenesis.
        Endocrinology. 1985; 117: 119
        • Long R.D.
        • Mitchell Jr., G.E.
        • Little C.O.
        Preintestinal disappearance of vitamin A in wethers fed cottonseed oil.
        J. Anim. Sci. 1969; 28 (Abstr.): 135
        • Lotthammer K.H.
        Importance of β-carotene for the fertility of dairy cattle.
        Feed stuffs. 1979; 51: 16
        • Lotthammer K.H.
        • Ahlswede L.
        Untersuchungen uber eine spezifische. Vitamin-A-unabhangige wirkung des β-carotins auf die fertilitat des rindes. 3. Mitt: Blutserumuntersuchungen.
        Dtsch. Tierarztl. Wochenschr. 1977; 84: 220
        • Lotthammer K.H.
        • Ahlswede L.
        • Meyer H.
        Untersuchungen uber eine spezifische. Vitamin-A-unabhangige wirkung des β-carotins auf die fertilitat des rindes. 2. Mitt. : Weitere klinische Befunde und Befruchtungsergebnisse.
        Dtsch. Tierarztl. Wochenschr. 1976; 83: 353
        • Lucy J.A.
        The fusion of biological membranes.
        Nature. 1970; 227: 815
        • Malecki J.
        Investigations on the influence of heavy cobalt granules on the appearance of estrus, on the estrous cycle and on the reproductive cycle and on some production and physiological factors in cows.
        Zesz. Nauk. Acad. Roln. Szczec. 1973; 41: 73
        • Maqsood M.
        Thyroid function in relation to reproduction of mammals and birds.
        Biol. Rev. Camb. Philos. Soc. 1952; 27: 281
        • Marx S.J.
        • Liberman U.A.
        • Eil C.
        Calciferols: actions and deficiencies in action.
        Vitam. Horm. 1983; 40: 235
        • Mason K.E.
        • Bryan W.L.
        Placental and mammary transfer of vitamin E in the rat.
        J. Nutr. 1940; 20: 501
        • Maynard L.A.
        • Loosli J.K.
        • Hintz H.F.
        • Warner R.G.
        Animal nutrition. Ch. 16. 7th ed. McGraw-Hill, New York, NY1979 (Page 472)
        • McConnell K.P.
        • Burton R.M.
        Selenium and spermatogenesis.
        in: Spallholz J.E. Martin J.L. Ganther H.E. Selenium in biology and medicine. AVI Publ. Co., Inc., Westport, CT1981: 132
        • McConnell K.P.
        • Burton R.M.
        • Kute T.
        • Higgins P.J.
        Selenoproteins from rat testis cytosol.
        Biochim. Biophys. Acta. 1979; 588: 113
        • McDonald R.J.
        • McKay G.W.
        • Thomson J.D.
        The use of organic iodine in the treatment of repeat breeder cows.
        Proc. IVth Int. Congr. Anim. Reprod. 1961; 3: 679
        • McMurray C.H.
        Copper deficiency in ruminants.
        in: Biological roles of copper. Ciba Found. Symp. 79. Excerpta Medica, Amsterdam, Neth1980: 183
        • Medina C.
        • Sprecher D.J.
        • Ax R.L.
        Selenium status of dairy cows in Wisconsin.
        J. Dairy Sci. 1986; 69 (Abstr.): 112
        • Meyer H.
        • Ahlswede L.
        • Lotthammer K.H.
        Untersuchungen uber eine spezifische, Vitamin-A-unabhangige wirkung des /3-carotins auf die fertilitat des rindes. 1. Mitt.: Versuch-sanstellung. Korperentwicklung und Eierstocks-funktion.
        Dtsch. Tierarztl. Wochenschr. 1975; 82: 444
        • Millar M.J.
        • Fischer M.I.
        • Elcoate P.V.
        • Mawson C.A.
        The effects of dietary zinc deficiency on the reproductive system of male rats.
        Can. J. Biochem. Physiol. 1958; 36: 557
        • Miller J.K.
        • Miller W.J.
        Experimental zinc deficiency and recovery of calves.
        J. Nutr. 1962; 76: 467
        • Miller J.K.
        • Swanson E.W.
        Performance and iodine metabolism of dairy cattle with iodine irradiation injury.
        J. Dairy Sci. 1966; 50: 90
        • Miller W.J.
        Mineral and vitamin nutrition of dairy cattle.
        J. Dairy Sci. 1981; 64: 1196
        • Miller W.J.
        • Pitts W.J.
        • Clifton C.M.
        • Schmittle S.C.
        Experimentally produced zinc deficiency in the goat.
        J. Dairy Sci. 1964; 47: 556
        • Mills C.F.
        Metabolic interactions of copper with other trace elements.
        in: Biological roles of copper. Ciba Found Symp. 79. Excerpta Medica, Amsterdam, Neth1980: 49
        • Moberg R.
        Possible influences of supplementary iodine, administered by evaporation on reproductive performance in cattle.
        in: Proc. IVth Int. Congr. Anim. Reprod. 3. 1961: 682
        • Moon R.C.
        • Itri L.M.
        Retinoids and cancer.
        in: The retinoids. 2. Academic Press, Inc., New York, NY1984: 327
        • Munro I.B.
        Infectious and non-infectious herd infertility in East Anglia.
        Vet. Rec. 1957; 69: 125
        • Morrow D.A.
        The role of nutrition in dairy cattle reproduction.
        in: Morrow D.A. Current therapy in theriogenology. WB Saunders Co., Philadelphia, PA1980: 449
        • Naor Z.
        • Catt K.J.
        Mechanism of action of gonadotropin-releasing hormone. Involvement of phospholipid turnover in leuteinizing hormone release.
        J. Biol. Chem. 1981; 256: 2226
        • National Research Council
        Nutrient requirements of dairy cattle.
        5th rev. ed. Natl. Acad. Sci., Washington, DC1978
        • Nedyjlkov K.
        • Krustev E.
        The application of zinc in the control of cow sterility.
        Vet. Med. Nauki. 1969; 6: 79
        • Nelson M.M.
        Relationship of dietary protein to reproductive physiology in female rats.
        Reproductive physiology and protein nutrition. Rutgers Univ. Press, New Brunswick, NJ1959 (Page 2)
        • Nelson M.M.
        • Evans H.M.
        Effect of pyridoxine deficiency on reproduction in the rat.
        J. Nutr. 1951; 43: 281
        • Nelson M.M.
        • Forfar J.O.
        Associations between drugs administered during pregnancy and congenital abnormalities of the fetus.
        Br. Med. J. 1971; 1: 523
        • Nelson M.M.
        • Lyons W.R.
        • Evans H.M.
        Maintenance of pregnancy in pyridoxine-deficient rats when injected with estrone and progesterone.
        Endocrinology. 1951; 48: 726
        • Neuweiler W.
        Die hypervitaminose und ihre beziehung zur schwagerschaft.
        Int. Z. Vitamforsch. 1951; 22: 392
        • Nierai S.M.
        • Kuzan F.B.
        • Senger P.L.
        Selenium in bovine spermatozoa.
        J. Dairy Sci. 1981; 64: 853
        • Norman A.W.
        • Roth J.
        • Orci L.
        The vitamin D endocrine system: steroid metabolism, hormone receptors, and biological response (calcium binding proteins).
        Endocr. Rev. 1982; 3: 331
        • O’Fallon J.V.
        • Chew B.P.
        The sub cellular distribution of β-carotene in bovine corpus luteum.
        Proc. Soc. Exp. Biol. Med. 1984; 177: 406
        • Omaye S.T.
        • Tillotson J.A.
        • Sauberlich H.E.
        Metabolism of L-ascorbic acid in the monkey.
        in: Seib P.A. Tolbert B.M. Ascorbic acid: chemistry, metabolism, and uses. Am. Chem. Soc., Washington, DC1982: 317
        • Ong D.E.
        • Chytl F.
        Vitamin A and cancer.
        Vitam. Horm. 1983; 40: 105
        • Ong D.E.
        • Crow J.A.
        • Chytil F.
        Radioimmunochemical determination of cellular retinol- and retinoic acid-binding proteins in cytosols of rat tissues.
        J. Biol. Chem. 1982; 257: 13385
        • Pappu A.S.
        • Fatterpaker P.
        • Sreenivasan A.
        Role of vitamin E in cellular processes.
        World Rev. Nutr. Diet. 1978; 31: 190
        • Parmer T.G.
        • Duby R.T.
        • Poos-Floyd M.I.
        Effects of a low β-carotene status on corpora lutea function in the Holstein dairy cow.
        J. Dairy Sci. 1986; 69 (Abstr.): 240
        • Peterson R.G.
        • Waldern D.E.
        A survey of dairy herds in the Fraser Valley of British Columbia to determine possible causes of unsatisfactory reproductive performance.
        Can. J. Anim. Sci. 1977; 57: 395
        • Peto R.
        • Doll R.
        • Buckley J.D.
        • Sporn M.B.
        Can dietary beta-carotene materially reduce human cancer rates?.
        Nature. 1981; 290: 201
        • Phillips P.H.
        • Lardy H.A.
        • Boyer P.D.
        • Werner G.M.
        The relationship of ascorbic acid to reproduction in the cow.
        J. Dairy Sci. 1941; 24: 153
        • Phillips P.H.
        • Lardy H.A.
        • Heizer E.E.
        • Rupel I.W.
        Sperm stimulation in the bull through the subcutaneous administration of ascorbic acid.
        J. Dairy Sci. 1940; 23: 873
        • Phillips P.H.
        • Stare F.J.
        The distribution of a reducing substance (vitamin C) in the tissues of fluorine-fed cows.
        J. Biol. Chem. 1934; 104: 351
        • Piper E.L.
        • Spears J.W.
        Influence of copper and zinc supplementation on mineral status, growth and reproductive performance of heifers.
        J. Anim. Sci. 1982; 55 (Abstr.): 319
        • Pitts W.J.
        • Miller W.J.
        • Fosgate O.T.
        • Morton J.D.
        • Clifton C.M.
        Effect of zinc deficiency and restricted feeding from two to five months of age on reproduction in Holstein bulls.
        J. Dairy Sci. 1966; 49: 995
        • Podesta E.J.
        • Milani A.
        • Steffen H.
        • Neher R.
        Steroidogenic action of calcium ions in isolated adrenocortical cells.
        Biochem. J. 1980; 186: 391
        • Pugh D.G.
        • Elmore R.G.
        • Hembree T.R.
        A review of the relationship between mineral nutrition and reproduction in cattle.
        Bovine Pract. 1985; 20: 10
        • Rakes A.H.
        • Owens M.P.
        • Britt J.H.
        • Whitlow L.W.
        Effects of adding beta-carotene to rations of lactating cows consuming different forages.
        J. Dairy Sci. 1985; 68: 1732
        • Riggs J.K.
        The length of time required for depletion of vitamin A reserves in range cattle.
        J. Nutr. 1940; 20: 491
        • Risco C.A.
        • Reynolds J.P.
        • Hird D.
        Uterine prolapse and hypocalcemia in dairy cows.
        J. Am. Vet. Med. Assoc. 1984; 185: 1517
        • Roberts A.B.
        • Sporn M.B.
        Cellular biology and biochemistry of the retinoids.
        in: The retinoids. 2. Academic Press, Inc., New York, NY1984: 209
        • Roberts S.J.
        Infertility in the cow.
        Veterinary obstetrics and genital diseases. S.J. Roberts, Publ., Ithaca, NY1971 (Page 376)
        • Rojas M.A.
        • Dyer I.A.
        • Cassatt W.A.
        Manganese deficiency in the bovine.
        J. Anim. Sci. 1965; 24: 664
        • Ronning M.
        • Berousek E.R.
        • Griffith J.L.
        • Gallup W.D.
        Carotene requirements of dairy cattle.
        Oklahoma Agric. Exp. Stn. Tech. Bull. 1959; : T-76
        • Root A.W.
        • Duckett G.
        • Sweetland M.
        • Reiter E.O.
        Effects of zinc deficiency upon pituitary function in sexually mature and immature male rats.
        J. Nutr. 1979; 109: 958
        • Rosenfeld I.
        • Beath O.A.
        Effect of selenium on reproduction in rats.
        Proc. Soc. Exp. Biol. Med. 1954; 87: 295
        • Rowley D.A.
        • Halliwell B.
        Superoxide dependent and ascorbate-dependent formation of hydroxyl radicals in the presence of copper salts: a physiologically significant reaction?.
        Arch. Biochem. Biophys. 1983; 225: 279
        • Ruh M.F.
        • Ruh T.S.
        Analysis of two forms of the molybdate-stabilized estrogen receptor.
        Endocrinology. 1984; 115: 1341
        • Salisbury G.W.
        A controlled experiment in feeding wheat germ oil as a supplement to the normal ration of bulls used for artificial insemination.
        J. Dairy Sci. 1944; 27: 551
        • Schams D.
        • Hoffmann B.
        • Lotthammer K.H.
        • Ahlswede L.
        Untersuchungen uber eine spezifische, Vitamin-A-unabhangige wirkung des β-carotins auf die fertilitat des rindes. 4. Mitt. : Auswirkung auf hormonale Parameter wahrend des Zyklus.
        Dtsch. Tierarztl. Wochenschr. 1977; 84: 307
        • Schingoethe D.J.
        • Kirkbirde C.A.
        • Palmer I.S.
        • Owens M.J.
        • Tucker W.L.
        Response of cows consuming adequate selenium to vitamin E and selenium supplementation prepartum.
        J. Dairy Sci. 1982; 65: 2338
        • Schingoethe D.J.
        • Parsons J.G.
        • Ludens F.C.
        • Tucker W.L.
        • Shave H.J.
        Vitamin E status of dairy cows fed stored feeds continuously or pastured during summer.
        J. Dairy Sci. 1978; 61: 1582
        • Scott M.L.
        Vitamin E.
        in: DeLuca H.F. Handbook of lipid research. Vol. 2. The fat-soluble vitamins. Plenum Press, New York, NY1978: 133
        • Segerson E.C.
        • Ganapathy S.N.
        Fertilization of ova in selenium/vitamin E-treated ewes maintained on two planes of nutrition.
        J. Anim. Sci. 1981; 51: 386
        • Segerson E.C.
        • Johnson B.H.
        Selenium/vitamin E and reproductive function in Angus bulls.
        J. Anim. Sci. 1979; 48 (Abstr.): 336
        • Segerson E.C.
        • Libby D.W.
        Ova fertilization and sperm number per fertilized ovum for selenium and vitamin E-treated Charolais cattle.
        Theriogenology. 1982; 17: 333
        • Segerson Jr., E.C.
        • Murray F.A.
        • Moxon A.L.
        • Redman D.R.
        • Conrad H.R.
        Selenium/vitamin E: role in fertilization of bovine ova.
        J. Dairy Sci. 1977; 60: 1001
        • Segerson Jr., E.C.
        • Riviere G.
        • Bullock T.R.
        • Thimaya S.
        • Ganapathy S.N.
        Uterine contractions and electrical activity in ewes treated with selenium and vitamin E.
        Biol. Reprod. 1980; 23: 1020
        • Segerson E.C.
        • Riviere G.J.
        • Dalton H.L.
        • Whitacre M.D.
        Retained placenta of Holstein cows treated with selenium and vitamin E.
        J. Dairy Sci. 1981; 64: 1833
        • Shemesh M.
        • Hansel W.
        • Strauss J.F.
        Calcium-dependent, cyclic nucleotide independent steroidogenesis in the bovine placenta.
        Cell Biol. 1984; 81: 6403
        • Sklan D.
        Carotene cleavage activity in the corpus luteum of cattle.
        Int. J. Vit. Nutr. Res. 1983; 53: 23
        • Smith D.G.
        • Senger P.L.
        • McCutchan J.F.
        • Landa C.A.
        Selenium and glutathione peroxidase distribution in bovine semen and selenium-75 retention by the tissues of the reproductive tract in the bull.
        Biol. Reprod. 1979; 20: 377
        • Smith Jr, J.C.
        Interrelationship of zinc and vitamin A metabolism in animal and human nutrition: a review.
        Clinical, biochemical and nutritional aspects of trace elements. Alan R. Liss, Inc., New York, NY1982 (Page 239)
        • Snyder W.E.
        • Stuart R.L.
        Nutritional role of beta-carotene in bovine fertility.
        J. Dairy Sci. 1981; 64 (Abstr.): 104
        • Soprano D.R.
        • Soprano K.J.
        • Goodman D.S.
        Retinol-binding protein and trans-thyretin mRNA levels in visceral yolk sac and liver during fetal development in the rat.
        Proc. Nad. Acad. Sci. 1986; 83: 7330
        • Spielman A.A.
        • Peterson W.E.
        • Fitch J.B.
        • Pomeroy B.S.
        General appearance, growth and reproduction of thyroidectomized bovine.
        J. Dairy Sci. 1945; 28: 329
        • Stansfield D.A.
        • Flint A.P.
        The entry of ascorbic acid into the corpus luteum in vivo and in vitro and the effect of luteinizing hormone.
        J. Endocrinol. 1967; 39: 27
        • Stockl W.
        • Weiser M.
        Kupfer-, mangan-, zink- und magnesiumgehalt in endo-krinen organen bein pferd, rind und schwein.
        Zentralbl. Veterinaermed. Reihe A. 1968; 15: 477
        • Swanson E.W.
        • Martin G.G.
        • Pardue F.E.
        • Gorman G.M.
        Milk production of cows fed diets deficient in vitamin A.
        J. Anim. Sci. 1968; 27: 541
        • Sutton T.S.
        • Krauss W.E.
        • Hansard S.L.
        The effect of vitamin A deficiency on the young male bovine.
        J. Dairy Sci. 1940; 23: 574
        • Swarup D.
        • Johnson N.P.
        Incorporation of labeled retinol and retinoic acid in bovine spermatozoa, effect of zinc on the rate of incorporation.
        Int. J. Vit. Nutr. Res. 1974; 44: 370
        • Swarup D.
        • Sekhon H.
        Incorporation of labeled retinol in bovine spermatozoa. III. Effect of zinc, fructose, and pH on the incorporation.
        Nutr. Rep. Int. 1975; 12: 255
        • Swarup D.
        • Sekhon H.
        Correlation of vitamin A and zinc concentration of seminal plasma to fertility of bovine semen.
        Nutr. Rep. Int. 1976; 13: 37
        • Talavera F.
        • Chew B.P.
        In vitro interaction of lipoproteins with retinol, retinoic acid and β-carotene on progesterone secretion by bovine luteal cells.
        J. Dairy Sci. 1987; 70 (Abstr.): 225
        • Talavera F.
        • Chew B.P.
        Retinol, retinoic acid and β-carotene ratios on progesterone secretion by bovine luteal cells.
        J. Dairy Sci. 1987; 70 (Abstr.): 119
        • Tappel A.L.
        Selenium-glutathione peroxidase: properties and synthesis.
        Curr. Top. Cell. Reg. 1984; 24: 87
        • Thomas J.W.
        • Moss S.
        The effect of orally administered molybdenum on growth, spermatogenesis and testes histology of young dairy bulls.
        J. Dairy Sci. 1951; 34: 929
        • Trinder N.
        • Hall R.J.
        • Renton C.P.
        The relationship between the intake of selenium and vitamin E on the incidence of retained placentae in dairy cows.
        Vet. Rec. 1973; 93: 641
        • Trinder N.
        • Woodhouse C.D.
        • Renton C.P.
        The effect of vitamin E and selenium on the incidence of retained placentae in dairy cows.
        Vet. Rec. 1969; 85: 550
        • Tsang C.P.W.
        • Grunder A.A.
        Effects of vitamin D deficiency on estradiol-17β metabolism in the laying hen.
        Endocrinology. 1984; 115: 2170
        • Ullrey D.E.
        Biological availability of fat-soluble vitamins: vitamin A and carotene.
        J. Anim. Sci. 1972; 35: 648
        • Underwood E.J.
        Trace elements in human and animal nutrition. 4th ed. Academic Press, New York, NY1977 (Page 170)
        • Underwood E.J.
        • Somers M.
        Studies on zinc nutrition in sheep. 1. The relation of zinc to growth, testicular development and spermatogenesis in young rams.
        Aust. J. Agric. Res. 1969; 20: 889
        • Vahlquist A.
        • Johnsson A.
        • Nygren K.G.
        Vitamin A transporting plasma proteins and female sex hormones.
        Am. J. Clin. Nutr. 1979; 32: 1433
        • Veldhuis J.D.
        • Klase P.A.
        Mechanisms by which calcium ions regulate the steroidogenie actions of luteinizing hormone in isolated ovarian cells in vitro.
        Endocrinology. 1982; 111: 1
        • Wagner W.C.
        Improving fertility in dairy cows.
        J. Am. Vet. Med. Assoc. 1962; 140: 939
        • Wang J.Y.
        • Hafi C.B.
        • Larson L.L.
        Effect of beta-carotene supplementation on releasable progesterone in Holstein heifers.
        J. Dairy Sci. 1985; 68 (Abstr.): 179
        • Wang J.Y.
        • Hafi C.B.
        • Larson L.L.
        Effect of supplemental beta-carotene on luteinizing hormone released in response to gonadotropin-releasing hormone challenge in ovari-ectomized Holstein cows.
        J. Dairy Sci. 1988; 71: 498
        • Wang J.Y.
        • Larson L.L.
        Effect of beta-carotene supplementation on estrous activity in dairy heifers.
        J. Dairy Sci. 1983; 66 (Abstr.): 239
        • Wang J.Y.
        • Larson L.L.
        • Owen F.G.
        Effect of beta-carotene supplementation on reproductive performance of dairy heifers.
        Theriogenology. 1982; 18: 461
        • Ward G.
        • Marion G.B.
        • Campbell C.W.
        • Dunham J.R.
        Influences of calcium intake and vitamin D supplementation on reproductive performance of dairy cows.
        J. Dairy Sci. 1971; 54: 204
        • Warembourg M.
        • Perret C.
        • Thomasset M.
        Distribution of vitamin D-dependent calcium-binding protein messenger ribonucleic acid in rat placenta and duodenum.
        Endocrinology. 1986; 119: 176
        • Wark J.D.
        • Tashjian Jr, A.H.
        Vitamin D stimulates prolactin synthesis by GH4C2, cells incubated in chemically defined medium.
        Endocrinology. 1982; 111: 1755
        • Wilson C.W.M.
        • Loh H.S.
        Vitamin C and fertility.
        Lancet. 1973; (ii): 859
        • Wilson J.G.
        Bovine functional infertility in Devon and Cornwall: response to manganese therapy.
        Vet. Rec. 1966; 79: 562
        • Wing J.M.
        Effect of source and season on apparent digestibility of carotene in forage by cattle.
        J. Dairy Sci. 1969; 52: 479
        • Wise T.
        Biochemical analysis of bovine follicular fluid: albumin, total protein, lysosomal enzymes, ions, steroids and ascorbic acid content in relation to follicular size, rank, atresia classification and day of estrous cycle.
        J. Anim. Sci. 1987; 64: 1153
        • Wooten E.
        • Nelson M.M.
        • Simpson M.E.
        • Evans H.M.
        Effect of pyridoxine deficiency on the gonadotrophic content of the anterior pituitary in the rat.
        Endocrinology. 1955; 56: 59
        • Wu S.H.
        • Oldfield J.E.
        • Whanger P.D.
        • Weswig P.H.
        Effect of selenium, vitamin E, and antioxidants on testicular function in rats.
        Biol. Reprod. 1973; 8: 625