Influence of Supplemental Fats on Reproductive Tissues and Performance of Lactating Cows

Journal of Dairy Science

Volumn 81, Issue 3, 1998, Pages 856-871

  Staples, C R ^a   Burke, J M ^a   Thatcher, W W ^a  

^a UNIVERSITY OF FLORIDA   (United States)

Author keywords

Fat; Progesterone; Prostaglandin; Reproduction

Indexed keywords

BOS TAURUS;

ANIMAL; ANIMAL FOOD; CALORIC INTAKE; CATTLE; FAT INTAKE; FEMALE; OVARY FOLLICLE; PHYSIOLOGY; REPRODUCTION; REVIEW;

ANIMAL NUTRITION PHYSIOLOGY; ANIMALS; CATTLE; DIETARY FATS; ENERGY INTAKE; FEMALE; OVARIAN FOLLICLE; REPRODUCTION;

EID: 0032018528     PISSN: 00220302     EISSN: None     Source Type: Journal    
DOI: 10.3168/jds.S0022-0302(98)75644-9     Document Type: Conference Paper

References (108)

1. Andrew, S. M., Tyrrell, H. F., C. K. Reynolds, and R. A. Erdman. 1991. Net energy for lactation of calcium salts of long-chain fatty acids for cows fed silage-based diets. J. Dairy Sci. 74:2588-2600.
2. Armstrong, J. D., E. A. Goodall, F. J. Gordon, D. A. Rice, and W. J. McCaughey. 1990. The effects of levels of concentrate offered and inclusion of maize gluten or fish meal in the concentrate on reproductive performance and blood parameter of dairy cows. Anim. Prod. 50:1-10.
3. Ashes, J. R., B. D. Sieber, S. K. Gulati, A. Z. Cuthbertson, and T. W. Scott. 1992. Incorporation of n-3 fatty acids of fish oil into tissue and serum lipids of ruminants. Lipids 27(8): 629-631.
4. Ballantine, H. T., and J. H. Herbein. 1989. Metabolic and calcium-regulating hormones in lactating Holstein and Jersey cows fed supplemental fat. J. Dairy Sci. 72(Suppl. 1): 316.(Abstr.)
5. Barton, B. A., and D. J. Carroll. 1992. Dietary crude protein and reproductive efficiency in dairy cows: considerations when designing or evaluating research protocols. Page 21 in Proc. 27th Pacific Northwest Anim. Nutr. Conf., Spokane, WA.
6. Bateman, H. G., J. N. Spain, and M. R. Ellersieck. 1996. Influence of by-product feeds and tallow on lactation performance of Holstein cows during two seasons. J. Dairy Sci. 79: 114-120.
7. Bauchart, D., F. Legay-Carmier, M. Doreau, and Gaillard. 1990. Lipid metabolism of liquid-associated and solid-adherent bacteria in rumen contents of dairy cows offered lipid-supplemented diets. Br. J. Nutr. 63:563-578.
8. Bauman, D. E., and C. L. Davis. 1975. Regulation of lipid metabolism. Page 496 in Digestion and Metabolism in the Ruminant. I. W. McDonald and A.C.I. Warner, ed. Univ. New England Publ. Unit, Armidale, New South Wales, Aus-tralia.
9. Beam, S. W., and W. R. Butler. 1997. Energy balance and ovarian follicle development prior to the first ovulation postpartum in dairy cows receiving three levels of dietary fat. Biol. Reprod. 56:133-142.
10. Blum J. W., F. Jans, W. Moses, D. Frohli, M. Zemp, M. Wanner, I. C. Hart, R. Thun, and U. Keller. 1985. Twenty-four hour pattern of blood hormone and metabolite concentrations in high-yielding dairy cows: effects of feeding low or high amounts of starch, or crystalline fat. Zentralbl. Veterinaermed. Reihe A 32:401-418.
11. Britt, J. H., D. W. Shaw, S. P. Washburn, and V. S. Hedgpeth. 1996. Endogenous progesterone during the luteal phase before insemination influences embryo recovery in lactating dairy cows. J. Anim. Sci. 74(Suppl. 1):225.(Abstr.)
12. Bruckental, I., D. Dori, M. Kaim, H. Lehrer, and Y. Folman. 1989. Effects of source and level of protein on milk yield and reproductive performance of high-producing primiparous and multiparous dairy cows. Anim. Prod. 48:319-329.
13. Burke, J. M., D. J. Carroll, K. E. Rowe, W. W. Thatcher, and F. Stormshak. 1996. Intravascular infusion of lipid into ewes stimulates production of progesterone and prostaglandin. Biol. Reprod. 55:169-175.
14. Burke, J. M., C. R. Staples, C. A. Risco, R. L. De La Sota, and W. W. Thatcher. 1996. Effect of ruminant grade menhaden fish meal on reproductive and productive performance of lactating dairy cows. J. Dairy Sci. 80:3386-3398.
15. Carroll, D. J., R. R. Grummer, and M. K. Clayton. 1992. Stimulation of luteal cell progesterone production by lipoproteins from cows fed control or fat-supplemented diets. J. Dairy Sci. 75:2205-2214.
16. Carroll, D. J., R. R. Grummer, and F. C. Mao. 1992. Progesterone production by cultured luteal cells in the presence of bovine low and high density lipoproteins purified by heparin affinity chromatography. J. Anim. Sci. 70:2516-2526.
17. Carroll, D. J., F. R. Hossain, and M. R. Keller. 1994. Effect of supplemental fish meal on the lactation and reproductive performance of dairy cows. J. Dairy Sci. 77:3058-3072.
18. Carroll, D. J., M. J. Jerred, R. R. Grummer, D. K. Combs, R. A. Rierson, and E. R. Hauser. 1990. Effects of fat supplementation and immature alfalfa to concentrate ratio on plasma progesterone, energy balance, and reproductive traits of dairy cattle. J. Dairy Sci. 73:2855-2863
19. Chilliard, Y. 1993. Dietary fat and adipose tissue metabolism in ruminants, pigs, and rodents: review. J. Dairy Sci. 76: 3897-3931.
20. Chilliard, Y., and J. F. Ottou. 1995. Duodenal infusion of oil in midlactation cows. 7. Interaction with niacin on responses to glucose, insulin, and β-agonist challenges. J. Dairy Sci. 78: 2452-2463.
21. Choi, B. R., and D. L. Palmquist. 1996. Effects of dietary fat on ruminal propionate and plasma insulin concentrations in lactating cows. J. Dairy Sci. 79(Suppl. 1):169.(Abstr.)
22. Choi, B. R., D. L. Palmquist, and M. S. Allen. 1996. Effects of endogenous cholecystokinin (CCK) on feed intake, plasma insulin, pancreatic polypeptide (PP) and metabolite levels in heifers fed fat. J. Dairy Sci. 79(Suppl. 1):169.(Abstr.)
23. Christensen, R. A., M. R. Cameron, J. H. Clark, J. K. Drackley, J. M. Lynch, and D. M. Barbano. 1994. Effects of amount of protein and ruminally protected amino acids in the diet of dairy cows fed supplemental fat. J. Dairy Sci. 77:1618-1629.
24. Christensen, R. A., J. K. Drackley, D. W. LaCount, and J. H. Clark. 1994. Infusion of four long-chain fatty acid mixtures into the abomasum of lactating dairy cows. J. Dairy Sci. 77: 1052-1069.
25. Coppock, C. E., and D. L. Wilks. 1991. Supplemental fat in high-energy rations for lactating cows: effects on intake, digestion milk yield, and composition. J. Anim. Sci. 69:3826-3837.
26. Cummins, K. A., and J. L. Sartin. 1987. Response of insulin, glucagon, and growth hormone to intravenous glucose challenge in cows fed high fat diets. J. Dairy Sci. 70:277-283.
27. Danet-Desnoyers, G., J. W. Johnson, S. F. O'Keefe, and W. W. Thatcher. 1993. Characterization of a bovine endometrial prostaglandin synthesis inhibitor (EPSI). Biol. Reprod. 48(Suppl. 1):115.(Abstr.)
28. DePeters, E. J., S. J. Taylor, C. M. Finley, and T. R. Famula. 1987. Dietary fat and nitrogen composition of milk from lactating cows. J. Dairy Sci. 70:1192-1201.
29. Donaldson, L., and W. Hansel. 1965. Histological study of bovine corpora lutea. J. Dairy Sci. 48:905-909.
30. Drackley, J. K., and J. P. Elliott. 1993. Milk composition, ruminal characteristics, and nutrient utilization in dairy cows fed partially hydrogenated tallow. J. Dairy Sci. 76:183-196.
31. Elliott, J. P., T. R. Overton, and J. K. Drackley. 1994. Digestibility and effects of three forms of mostly saturated fatty acids. J. Dairy Sci. 77:789-798.
32. Elattar, T. M., and H. S. Lin. 1989. Comparison of the inhibitory effect of polyunsaturated fatty acids on prostaglandin synthesis I oral squamous carcinoma cells. Prostaglandins Leukotrines Essent. Fatty Acids 38:119-125.
33. Erickson, P. J., M. R. Murphy, and J. H. Clark. 1992. Supplementation of dairy cow diets with calcium salts of long-chain fatty acids and nicotinic acid in early lactation. J. Dairy Sci. 75:1078-1089.
34. Fellner, V., F. D. Sauer, and J.K.G. Kramer. 1995. Steady-state rates of linoleic acid biohydrogenation by ruminal bacteria in continuous culture. J. Dairy Sci. 78:1815-1823.
35. Ferguson, J. D., D. Sklan, W. V. Chalupa, and D. S. Kronfeld. 1990. Effects of hard fats on in vitro and in vivo rumen fermentation, milk production, and reproduction in dairy cows. J. Dairy Sci. 73:2864-2879.
36. Gagliostro, G., and Y. Chilliard. 1991. Duodenal rapeseed oil infusion in early and midlactation cows. 2. Voluntary intake, milk production, and composition. J. Dairy Sci. 74:499-509.
37. Gagliostro, G., Y. Chilliard, and M.-J. Davicco. 1991. Duodenal rapeseed oil infusion in early and midlactation cows. 3. Plasma hormones and mammary apparent uptake of metabolites. J. Dairy Sci. 74:1893-1903.
38. Garcia-Bojalil, C. M. 1993. Reproductive, productive, and immunological responses by Holstein dairy cows fed diets varying in concentration and ruminal degradability of protein and supplemented with ruminally-inert fat. Ph.D. Diss., Univ. Florida, Gainesville.
39. Grummer, R. R. 1991. Effect of feed on the composition of milk fat. J. Dairy Sci. 74:3244-3257.
40. Grummer, R. R., and D. J. Carroll. 1988. A review of lipoprotein cholesterol metabolism: importance to ovarian function. J. Anim. Sci. 66:3160-3173.
41. Grummer, R. R., and D. J. Carroll. 1991. Effects of dietary fat on metabolic disorders and reproductive performance of dairy cattle. J. Anim. Sci. 69:3838-3852.
42. Grummer, R. R., and M. T. Socha. 1989. Milk fatty acid composition and plasma energy metabolite concentrations in lactating cows fed medium-chain triglycerides. J. Dairy Sci. 72: 1996-2001.
43. Guilbault, L. A., W. W. Thatcher, M. Drost, and S. M. Hopkins. 1984. Source of F series prostaglandins during the early postpartum period in cattle. Biol. Reprod. 31:879-887.
44. Gurr, M. I., and J. L. Harwood. 1991. Dietary lipids: implications for health and disease. Page 162 in Lipid Biochemistry. M. I. Gurr and J. L. Harwood, ed. Chapman and Hall, London, United Kingdom.
45. Harrison, J. H., J. P. McNamara, and R. L. Kincaid. 1995. Production responses in lactating dairy cattle fed rations high in fat. J. Dairy Sci. 78:181-193.
46. Hawkins, D. E., K. D. Niswender, G. M. Oss, C. L. Moeller, K. G. Odde, H. R. Sawyer, and G. D. Niswender. 1995. An increase in serum lipids increases luteal lipid content and alters the disappearance rate of progesterone in cows. J. Anim. Sci. 73:541-545.
47. Hightshoe, R. B., R. C. Cochran, L. R. Corah, G. H. Kiracofe, D. L. Harmon, and R. C. Perry. 1991. Effects of calcium soaps of fatty acids on postpartum reproductive function in beef cows. J. Anim. Sci. 69:4097-4103.
48. Holter, J. B., H. H. Hayes, W. E. Urban, Jr., and A. H. Duthie. 1992. Energy balance and lactation response in Holstein cows supplemented with cottonseed with or without calcium soap. J. Dairy Sci. 75:1480-1494.
49. Horner, J. L., C. E. Coppock, G. T. Schelling, J. M. Labore, and D. H. Nave. 1986. Influence of niacin and whole cottonseed on intake, milk yield and composition, and systemic responses of dairy cows. J. Dairy Sci. 69:3087-3093.
50. Howard, J. J., R. G. Scott, and J. H. Britt. 1990. Associations among progesterone, estradiol-17β, and prostaglandin in cattle treated with hCG during diestrus to extend corpus luteum function. Prostaglandins 40:51-70.
51. Hussein, H. S., N. R. Merchen, and G. C. Fahey, Jr. 1996. Effects of chemical treatment of whole canola seed on digestion of long-chain fatty acids by steers fed high or low forage diets. J. Dairy Sci. 79:87-97.
52. Jenkins, K. J. 1988. Factors affecting poor performance and scours in preruminant calves fed corn oil. J. Dairy Sci. 71: 3013-3020.
53. Jenkins, T. C., H. G. Bateman, and S. M. Block. 1996. Butylsoyamide increases unsaturation of fatty acids in plasma and milk of lactating dairy cows. J. Dairy Sci. 79:585-590.
54. Jenkins, T. C., and B. F. Jenny. 1989. Effect of hydrogenated fat on feed intake, nutrient digestion, and lactation performance of dairy cows. J. Dairy Sci. 72:2316-2324.
55. Jenkins, T. C., and D. L. Palmquist. 1984. Effect of fatty acids or calcium soaps on rumen and total nutrient digestibility of dairy rations. J. Dairy Sci. 67:978-986.
56. Jerred, M. J., D. J. Carroll, D. K. Combs, and R. R. Grummer. 1990. Effects of fat supplementation and immature alfalfa to concentrate ratio on lactation performance of dairy cattle. J. Dairy Sci. 73:2842-2854.
57. Johnson, J. C., Jr., P. R. Utley, and B. G. Mullinix, Jr. 1988. Effects of adding fat and lasalocid to diets of dairy cows. J. Dairy Sci. 71:2151-2165.
58. Kaduce, T. L., A. A. Spector, and R. S. Bar. 1982. Linoleic acid metabolism and prostaglandin production by cultured bovine pulmonary artery endothelial cells. Arteriosclerosis 2:380-389.
59. Khorasani, G. R., P. H. Robinson, G. de Boer, and J. J. Kennelly. 1991. Influence of canola fat on yield, fat percentage, fatty acid profile, and nitrogen fractions in Holstein milk. J. Dairy Sci. 74:3891-3899.
60. Klusmeyer, T. H., and J. H. Clark. 1991. Effects of dietary fat and protein on fatty acid flow to the duodenum and in milk produced by dairy cows. J. Dairy Sci. 74:3055.
61. Knickerbocker, J. J., W. W. Thatcher, D. B. Foster, D. Wolfenson, F. F. Bartol, and D. Caton. 1986. Uterine prostaglandin and blood flow responses to estradiol-17β in cyclic cattle. Prostaglandins 31:757-776.
62. Langhout, D. J., L. J. Spicer, and R. D. Geisert. 1991. Development of a culture system for bovine granulosa cells: effects of growth hormone, estradiol, and gonadotropins on cell proliferation, steroidogenesis, and protein synthesis. J. Anim. Sci. 69: 3321-3384.
63. Lough, D. S., L. D. Muller, R. S. Kensinger, T. F. Sweeney, and L. C. Griel, Jr. 1988. Effect of added fat and bovine somatotropin on the performance and metabolism of lactating dairy cows. J. Dairy Sci. 71:1161-1169.
64. Lucy, M. C., R. L. De La Sota, C. R. Staples, and W. W. Thatcher. 1993. Ovarian follicular populations in lactating dairy cows treated with recombinant bovine somatotropin (sometribove) or saline and fed diets differing in fat content and energy. J. Dairy Sci. 76:1014-1027.
65. 2α and ovarian function in cycling Holstein heifers. Page 119 in Livestock Reproduction in Latin America. Int. At. Energy Agency, Vienna, Austria.
66. Lucy, M. C., C. R. Staples, F. M. Michel, and W. W. Thatcher. 1991. Energy balance and size and number of ovarian follicles detected by ultrasonography in early postpartum dairy cows. J. Dairy Sci. 74:473-482.
67. 2α, luteinizing hormone, and follicular growth. J. Dairy Sci. 74:483-489.
68. Lucy, M. C., C. R. Staples, W. W. Thatcher, P. S. Erickson, R. M. Cleale, J. L. Firkins, J. H. Clark, M. R. Murphy, and B. O. Brodie. 1992. Influence of diet composition, dry matter intake, milk production and energy balance on time of postpartum ovulation and fertility in dairy cows. Anim. Prod. 54: 323-331.
69. McNamara, J. P., J. H. Harrison, R. L. Kincaid, and S. S. Waltner. 1995. Lipid metabolism in adipose tissue of cows fed high fat diets during lactation. J. Dairy Sci. 78:2782-2796.
70. Mohamed, O. E., L. D. Satter, R. R. Grummer, and F. R. Ehle. 1988. Influence of dietary cottonseed and soybean on milk production and composition. J. Dairy Sci. 71:2677-2688.
71. Moore, J. H., and W. W. Christie. 1979. Lipid metabolism in the mammary gland of ruminant animals. Progr. Lipid Res. 17:347.
72. Murphy, M., P. Udén, D. L. Palmquist, and H. Wiktorsson. 1987. Rumen and total diet digestibilities in lactating cows fed diets containing full-fat rapeseed. J. Dairy Sci. 70:1572-1582.
73. Niswender, G. D., and T. M. Nett. 1994. Corpus luteum and its control in infraprimate species. Page 781 in The Physiology of Reproduction. 2nd ed. E. Knobil and J. D. Neill, ed. Raven Press, Ltd., New York, NY.
74. Ohajuruka, O. A., Z. Wu, and D. L. Palmquist. 1991. Ruminal metabolism, fiber, and protein digestion by lactating cows fed calcium soap or animal-vegetable fat. J. Dairy Sci. 74: 2601-2609.
75. Oldick, B. S., C. R. Staples, W. W. Thatcher, and P. Gyawu. 1997. Abomasal infusion of glucose and fat - effect on digestion, production, and ovarian and uterine function of cows. J. Dairy Sci. 80:1315-1328.
76. Palmquist, D. L. and T. C. Jenkins. 1980. Fat in lactation rations: review. J. Dairy Sci. 63:1-14.
77. Palmquist, D. L., and D. J. Kinsey. 1994. Lipolysis and biohydrogenation of fish oil by ruminal microorganisms. J. Dairy Sci. 77(Suppl. 1):350.(Abstr.)
78. Palmquist, D. L., and E. A. Moser. 1981. Dietary fat effects on blood insulin, glucose utilization, and milk protein content of lactating cows. J. Dairy Sci. 64:1664-1670.
79. Palmquist, D. L., and W. P. Weiss. 1994. Blood and hydrolyzed feather meals as sources of undegradable protein in high fat diets for cows in early lactation. J. Dairy Sci. 77:1630-1643.
80. Romo, G. A., D. P. Casper, R. A. Erdman, and B. B. Teter. 1996. Abomasal infusion of cis or trans fatty acid isomers and energy metabolism of lactating dairy cows. J. Dairy Sci. 79: 2005-2015.
81. Ruegsegger, G. J., and L. H. Schultz. 1985. Response of high producing dairy cows in early lactation to the feeding of heat-treated whole soybeans. J. Dairy Sci. 68:3272-3279.
82. Ryan, D. P., R. A. Spoon, and G. L. Williams. 1992. Ovarian follicular characteristics, embryo recovery, and embryo viability in heifers fed high-fat diets and treated with follicle-stimulating hormone. J. Anim. Sci. 70:3505-3513.
83. Salfer, J. A., J. G. Linn, D. E. Otterby, and W. P. Hansen. 1995. Early lactation responses of Holstein cows fed a rumeninert fat prepartum, postpartum, or both. J. Dairy Sci. 78: 368-377.
84. Schingoethe, D. J., and D. P. Casper. 1991. Total lactational response to added fat during early lactation. J. Dairy Sci. 74: 2617-2622.
85. Schneider, B. H., D. Sklan, W. Chalupa, and D. S. Kronfeld. 1988. Feeding calcium salts of fatty acids to lactating cows. J. Dairy Sci. 71:2143-2150.
86. Scott, T. A., R. D. Shaver, L. Zepeda, B. Yandell, and T. R. Smith. 1995. Effects of rumen-inert fat on lactation, reproduction, and health of high producing Holstein herds. J. Dairy Sci. 78:2435-2451.
87. Simas, J. M., J. T. Huber, Z. Wu, K. H. Chen, S. C. Chan, C. B. Theurer, and R. S. Swingle. 1995. Influence of steam-flaked sorghum grain and supplemental fat on performance of dairy cows in early lactation. J. Dairy Sci. 78:1526-1533.
88. Sklan, D., E. Bogin, Y. Avidar, and S. Gur-arie. 1989. Feeding calcium soaps of fatty acids to lactating cows: effect on production, body condition, and blood lipids. J. Dairy Res. 56: 675-681.
89. Sklan, D., M. Kaim, U. Moallem, and Y. Folman. 1994. Effect of dietary calcium soaps on milk yield, body weight, reproductive hormones, and fertility in first parity and older cows. J. Dairy Sci. 77:1652-1660.
90. Sklan, D., U. Moallem, and Y. Folman. 1991. Effect of feeding calcium soaps of fatty acids on production and reproductive responses in high producing lactating cows. J. Dairy Sci. 74: 510-517.
91. Smith, D. H., K. L. Roehrig, D. L. Palmquist, and F. L. Schanbacher. 1987. Effect of dietary fat and lactation status on insulin binding to bovine milk fat globule membrane. J. Dairy Sci. 70:1557-1562.
92. Smith, W. L., and L. J. Marnett. 1991. Prostaglandin endoperoxide synthase: structure and catalysis. Biochim. Biophys. Acta 1083:1-17.
93. Son, J., R. J. Grant, and L. L. Larson. 1996. Effects of tallow and escape protein on lactational and reproductive performance of dairy cows. J. Dairy Sci. 79:822-830.
94. Spicer, L. J., E. Alpizar, and S. E. Echternkamp. 1993. Effects of insulin, insulin-like growth factor I, and gonadotropins on bovine granulosa cell proliferation, progesterone production, estradiol production, and(or) insulin-like growth factor I production in vitro. J. Anim. Sci. 71:1232-1241.
95. Spicer, L. J., R. K. Vernon, W. B. Tucker, R. P. Wettemann, J. F. Hogue, and G. D. Adams. 1993. Effects of inert fat on energy balance, plasma concentrations of hormones, and reproduction in dairy cows. J. Dairy Sci. 76:2664-2673.
96. Staples, C. R., W. W. Thatcher, and J. M. Burke. 1997. Influences of dietary energy, fat, and protein on reproductive performance of lactating dairy cows. Pages 204-221 in Proc. IX Int. Conf. on Prod. Dis. Farm Anim. Ferdinand Enke Verlag, Stuttgart, Germany.
97. Stegeman, G. A., D. P. Casper, D. J. Schingoethe, and R. J. Baer. 1992. Lactational responses of dairy cows fed unsaturated dietary fat and receiving bovine somatotropin. J. Dairy Sci. 75:1936-1945.
98. Sukhija, P. S., and D. L. Palmquist. 1990. Dissociation of calcium soaps of long-chain fatty acids in rumen fluid. J. Dairy Sci. 73:1784-1799.
99. Talavera, F., C. S. Park, and G. L. Williams. 1985. Relationships among dietary lipid intake, serum cholesterol and ovarian function in Holstein heifers. J. Anim. Sci. 60:1045-1051.
100. Thatcher, W. W., C. R. Staples, G. Danet-Desnoyers, B. Oldick, and E.-P. Schmitt. 1994. Embryo health and mortality in sheep and cattle. J. Anim. Sci. 72(Suppl. 3):16.
101. Thomas, M. G., and G. L. Williams. 1996. Metabolic hormone secretion and FSH-induced superovulatory responses of beef heifers fed dietary fat supplements containing predominantly saturated or polyunsaturated fatty acids. Theriogenology 45: 451-458.
102. Van Nevel, C., and D. I. Demeyer. 1995. Lipolysis and biohydrogenation of soybean oil in the rumen in vitro: inhibition by antimicrobials. J. Dairy Sci. 78:2797-2806.
103. Weber, P. C., and A. Sellmayer. 1990. Modification of the eicosanoid system and cell signaling by precursor fatty acids. Adv. Prostaglandin Thromboxane Leukotriene Res. 21: 217-224.
104. Wehrman, M. E., T. H. Welsh, Jr., and G. L. Williams. 1991. Diet-induced hyperlipidemia in cattle modifies the intrafollicular cholesterol environment, modulates ovarian follicular dynamics, and hastens the onset of postpartum luteal activity. Biol. Reprod. 45:514-522.
105. Wilkins, J. F., W. D. Hoffman, S. K. Larsson, B. A. Hamilton, D. W. Hennessy, and M. A. Hilard. 1996. Protected lipid/protein supplement improves synchrony of oestrus and conception rate in beef cows. Page 19 in Congr. Progr. 13th Int. Congr. Anim. Reprod., Sidney, New South Wales, Australia.
106. Williams, G. L. 1989. Modulation of luteal activity in postpartum beef cows through changes in dietary lipid. J. Anim. Sci. 67:785-793.
107. Wolfenson, D., F. F. Bartol, L. Badinga, C. M. Barros, D. N. Marple, K. Cummins, D. Wolfe, M. C. Lucy, T. E. Spencer, and W. W. Thatcher. 1993. Secretion of PGF-2α and oxytocin during hyperthermia in cyclic and pregnant heifers. Theriogenology 39:1129-1141.
108. Yang, Y. T., R. L. Baldwin, and W. N. Garrett. 1978. Effects of dietary lipid supplementation on adipose tissue metabolism in lambs and steers. J. Anim. Sci. 47:686-690.