Hostname: page-component-cb9f654ff-lqqdg Total loading time: 0 Render date: 2025-09-10T14:21:21.506Z Has data issue: false hasContentIssue false
  • English
  • Français

A review of oestrous behaviour and detection in dairy cows

Published online by Cambridge University Press:  27 February 2018

J. S. Stevenson
J. S. Stevenson*
Affiliation:
Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506-0201, USA
Get access

Abstract

A number of measurable physiological events characteristically occur and cause changes during the perioestrual period including the classical, diagnostic sign of standing behaviour. The onset of oestrus coincides with peak titres of oestradiol-17β that subsequently induce the preovulatory surge of LH within 1 to 3 h and ovulation of a mature follicle some 24 to 32 h after the onset of oestrus. Although detection efficiencies are consistently greater in higher producing herds, oestrus-detection efficiency generally has declined in recent years as herd size and milk production have increased. New technologies have introduced some needed assistance for detecting cows in oestrus. These include various in expensive heat mount detectors to more sophisticated electronic gadgetry, such aspedometry and radiotelemetric sensors that detect temperature, tissue impedance, and pressure. Oestrus detection aids are usually more efficient but not necessarily more accurate than visual observation. Differences in housing and environmental conditions, in addition to labor inputs, costs, and efficacies, result in variable acceptance of such technologies. Detection efficiency and accuracy can be improved by simultaneous use of synergistic technologies; those that compliment each other and monitor different indicators of oestrus. Combining technologies for simultaneous measurements of several physiological events associated specifically with the onset of oestrus and their radiotelemetrically signaling to a central computer for subsequent analysis should provide greater efficiency ofoestrus detection with fewer false positives. The ultimate goal of determining the onset of oestrus or ovulation is to predict the optimal timing for insemination. Ultimately, herd personnel must interpret information gathered by these technologies and judge whether or not and when to inseminate cows based on their visual inspection of identified cows.

Information

Type
Invited Papers
Information
BSAP Occasional Publication , Volume 26 , Issue 1: Fertility in the High Producing Dairy Cow , January 2001 , pp. 43 - 62
Copyright
Copyright © British Society of Animal Science 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

References

Allrich, R.D. 1993. Estrous behavior and detection in cattle. Veterinary Clinics in North America: FoodAnimal Practice 9:249–262.Google Scholar
Allrich, R.D. 1994. Endocrine and neural control of estrus in dairy cows. Journal of Dairy Science 77:2738–2744.Google Scholar
Anon. 1992. Progesterone tests show dairy farmers are breeding cows not in heat. Agribusiness Dairyman. 7:16–17.Google Scholar
Amyot, E. and Hurnik, J.F. 1987. Diurnal patterns of estrous behavior of dairy cows housed in a free stall. Canadian Journal ofAnimal Science 67:605–614.CrossRefGoogle Scholar
Andersson, L., inventor. 1999. Identity and cow estrus indicator. Alfa Laval Agri AB, Sweden. U.S. Patent No. 5,857,434.Google Scholar
Arney, D.R., Kitwood, S.E., and Phillips, C.J.C. 1994. The increase in activity during oestrus in dairy cows. Applied Animal Behaviour Science 40:211–218.Google Scholar
Bar-Peled, U., Maltz, E., Bruckental, I., Folman, Y., Kali, Y., Gacitua, H., and Lehrer, A.R. 1995. Relationships between frequent milking or suckling in early lactation and milk production of high producing dairy cows. Journal of Dairy Science 78:2726–2736.CrossRefGoogle ScholarPubMed
Barr, H.L. 1975. Influence of estrus detection on days open in dairy herds. Journal of Dairy Science 58:246–247.CrossRefGoogle ScholarPubMed
Bartlett, P.C., Kirk, J., Coe, P., Marteniuk, J., and Mather, E.C. 1987. Descriptive epidemiology of anestrus in Michigan Holstein-Friesian cattle. Theriogenology 27:459–476.Google Scholar
Britt, J.H. 1980. Testosterone treatment of cows for detection of estrus, pp.174–177. Current Therapy in Theriogenology. W.B. Saunders Co., Philadelphia, PA.Google Scholar
Britt, J.H., Scott, R.G., Armstrong, J.D., and Whitacre, M.D. 1986. Determinants of estrous behavior in lactating Holstein cows. Journal of Dairy Science 69:2195–2202.CrossRefGoogle ScholarPubMed
Butler, W.R., and Smith, R.D. 1989. Interrelationships between energy balance and postpartum reproductive function in dairy cattle. Journal of Dairy Science 72:767–783.Google Scholar
Call, E.J.P., and Stevenson, J.S. 1985. Current challenges in reproductive management Journal of Dairy Scienc 68:2799–2805.Google Scholar
Cartmill, J.A., Hensley, B.A., El-Zarkouny, S.Z., Rozell, T.G., Smith, J.F., and Stevenson, J.S.. 1999. An alternative Al-breeding protocol during summer heat stress. Journal of Dairy Science 82:(Suppl. 1):48 (Abstr.).Google Scholar
Cattell, M.B., Dinsmore, R.P., Stevens, R.D., and Niswender, G.D. 1994. Clinical field trial for remote radio telemetry heat mount detection system. Proceedings of the Annual American Association ofBovine Practitioners, pp 173–176.Google Scholar
Cavestany, D. and Foote, R.H. 1985. The use of milk progesterone and electronic vaginal probes as aids in large dairy herd reproductive management. Cornell Veterinarian 75:441–453.Google Scholar
Claycomb, R.W., Delwiche, M.J., Munro, C.J., and BonDurant, R.H. 1996. Enzyme immunoassasy for on-line sensing of milk progesterone. Transactions of the American Society Agricultural Engineers 39:729–734.Google Scholar
Coe, B.L. and Allrich, R.D. 1989. Relationship between endogenous estradiol-17β and estrous behavior in heifers. Journal ofAnimal Science 67:1546–1551.Google ScholarPubMed
De la Sota, R.L., Burke, J.M., Risco, C.A., Moreira, F., DeLorenzo, M.A., and Thatcher, W.W. 1998. Evaluation of timed insemination during summer heat stress in lactating dairy cattle. Theriogenology 49:761–770.Google Scholar
Dohi, H., Yamada, A., Tsuda, S., Sumikawa, T., and Entsu, S. 1993. A pressure-sensitive sensor for measuring the characteristics of standing mounts of cattle. Journal of Animal Science 71:369–372.Google Scholar
Dransfield, M.G.B., Nebel, R.L., Pearson, R.E., and Warnick, L.D. 1998. Timing of insemination for dairy cows identified in estrus by a radiotelemetric estrus detection system. Journal of Dairy Science 81:1874–1882.Google Scholar
Esslemont, R.J., 1974a. Economic and husbandry aspects of the manifestation and detection of oestrus in cows. I. Economic aspects. ADAS Quarterly Review 12:175–184.Google Scholar
Esslemont, R.J. 1974b. Economic and Husbandry aspects of the manifestation and detection of oestrus in cows. III. The detection of oestrus. ADAS Quarterly Review 15:83–95.Google Scholar
Esslemont, R.J., and Bryant, M.J. 1974. Economic and husbandry aspects of die manifestation and detection of oestrus in cows. II. The manifestation of oestrus in cattle. ADAS Quarterly Review 13:19–26.Google Scholar
Esslemont, R.J., Glencross, R.G., Bryant, M.J., and Pope, G.S. 1980. A quantitative study of pre-ovulatory behaviour in cattle (British Friesian heifers). Applied Animal Ethology 6:1–17.CrossRefGoogle Scholar
Ezov, N., Maltz, E., Yarom, R., Lewis, G.S., Schindler, D., Ron, M., Aizinbud, E., and Lehrer, A.R. 1990. Cell density, fluid volume and electrolyte content of bovine vulvar tissue during oestrus and diestrus. Animal Reproduction Science 22:281–288.Google Scholar
Farris, E.J. 1954. Activity of dairy cows during estrus. Journal of American Veterinary Medical Association 125:117.Google ScholarPubMed
Faust, M.A., McDaniel, B.T., Robison, O.W., and Britt, J.H. 1988. Environmental and yield effects on reproduction in primiparous Holsteins. Journal of Dairy Science 71:3092–3099.Google Scholar
Fonseca, F.A., Britt, J.H., McDaniel, B.T., Wilk, J.C., and Rakes, A.H. 1983. Reproductive traits of Holsteins and Jerseys. Effects of age, milk yield, and clinical abnormalities on involution of cervix and uterus, ovulation, estrous cycles, detection of estrus, conception rate and days open. Journal of Dairy Science 66:1128–1147.Google Scholar
Foote, R.H. 1975. Estrus detection and estrus detection aids. Journal of Dairy Science 58:248–256.Google Scholar
Ford, S.P., Chenault, J.R., and Echternkamp, S.E. 1979. Uterine blood flow of cows during the oestrous cycle and early pregnancy: Effect of the conceptus on the uterine blood supply. Journal of Reproduction andFertility 56:53–62.Google Scholar
Foulkes, J.A., Cookson, A.D., and Sauer, M.J. 1982. Artificial insemination of cattle based on daily enzyme immunoassay of progesterone in whole milk. British Veterinary Journal 111:302–303.Google Scholar
French, J.M., Moore, G.F., Perry, G.C., and Long, S.E. 1989. Behavioural predictors of oestrus in domestic cattle, Bos taunts. Animal Behaviour 38:913–919.Google Scholar
Gettens, J.W., Sigrimis, N.A., and Scott, N.R., inventors. 1986. Passive activity monitor for livestock. Cornell Research Foundation, Inc., Ithaca, NY. U.S. PatentNo. 4,618,861.Google Scholar
Gwazdauskas, F.C., Lineweaver, J.A., and McGilliard, M.L. 1983. Environmental and managements factors affecting estrous activity in dairy cattle. Journal of Dairy Science 66:1510–1514.Google Scholar
Gwazdauskas, F.C., Whittier, W.D., Nebel, R.L., Sprecher, D.J., and McGilliard, M.L. 1990. Effectiveness of rump-mounted devices and androgenized females for detection of estrus in dairy cattle. Journal of Dairy Science 73:2965–2970.Google Scholar
Hackett, A.J. and Lin, C.Y. 1985. Comparison of females treated with oestradiol or testosterone to detect oestrus in dairy cattle maintained indoors year-round. Animal Reproduction Science 9:119–123.Google Scholar
Hackett, A.J. and McAllister, A.J. 1984. Onset of estrus in dairy cows maintained indoors year-round. Journal of Dairy Science 67:1793–1797.CrossRefGoogle ScholarPubMed
Hageman, W.H., Shook, G.E., and Tyler, W.J. 1991. Reproductive performance in genetic lines selected for high or average milk yield. Journal ofDairy Science 74:4366–4376.Google Scholar
Hansen, W.P., Otterby, D., Linn, J.G., Anderson, J.F., and Eggert, R.G. 1994. Multi-farm use of bovine somatotropin for two consecutive lactations and its effects on lactational performance, health, and reproduction. Journal ofDairy Science 77:94–110.Google Scholar
Harrison, R.O., Young, J.W., Freeman, A.E., Ford, S.P., and Conley, A.J. 1990. Increased milk production versus reproductive and energy status of high producing dairy cows. Journal ofDairy Science 73:2749–2758.Google ScholarPubMed
Hawk, H.W., Conley, H.H. and Kiddy, C.A. 1984. Estrus-related odors in milk detected by trained dogs. Journal ofDairy Science 67:392–397.Google Scholar
Heersche, G. Jr. and Nebel, R.L. 1994. Measuring efficiency and accuracy of detection of estrus. Journal of Dairy Science 77:2754–2761.Google Scholar
Hein, K.G. and Allrich, R.D. 1992. Influence of exogenous adrenocorticotropic hormone on estrous behavior in cattle. Journal ofAnimal Science 70:243–247.Google Scholar
Helmer, S.D. and Britt, J.H. 1985. Mounting behavior as affected by stage of estrous cycle in Holstein heifers. Journal of Dairy Science 68:1290–1296.Google Scholar
Herrick, J. 1988. Estrus detection in the bovine. LargeAnimal Veterinarian 43:32–36.Google Scholar
Hixon, J.E., Pimental, C.A., Weston, P.G., Hafetz, E.P., Shanks, R.D., and Hansel, W. 1983. A luteolytic interaction between estradiol benzoate and prostaglandin F in cattle. Journal ofAnimal Science 56:1190–1197.Google Scholar
Holmann, F.J., Blake, R.W., and Shumway, C.R. 1987. Economic evaluation of fourteen methods of estrous detection. Journal ofDairy Science 70:186–194.Google ScholarPubMed
Hurnik, J.F. 1987. Sexual behavior of female domestic mammals. Veterinary Clinics in North America: Food Animal Practice 3:423–461.Google Scholar
Hurnik, J.F. and King, G.J. 1987. Estrous behavior in confined beef cows. Journal of Animal Science 65:431–438.Google Scholar
Hurnik, J.F., King, G.J., and Robertson, H.A. 1975. Estrous and related behaviour in postpartum Holstein cows. Applied Animal Ethology 2:55–68.Google Scholar
Kennedy, A.D. and Ingalls, J.R. 1995. Estrus detection with activity tags in dairy cows housed in tie-stalls. Canadian Journal ofAnimal Science 75:633–636.Google Scholar
Kiddy, C.A. 1977. Variation in physical activity as an indication of estrus in dairy cows. Journal ofDairy Science 60:235–243.Google Scholar
Kiddy, C.A., Mitchell, D.S., Bolt, D.J., and Hawk, H.W. 1978. Detection of estrus-related odors in cows by trained dogs. Biology of Reproduction 19:389–395.Google Scholar
Kiddy, C.A., Mitchell, D.S., and Hawk, H.W. 1984. Estrus-related odors in body fluids of dairy cows. Journal of Dairy Science 67:388–391.Google Scholar
King, G.J., Hurnik, J.F., and Robertson, H.A. 1976. Ovarian function and estrus in dairy cows during early lactation. Journal ofAnimal Science 42:688–692.Google Scholar
Kirby, C.J., Wilson, S.J., and Lucy, M.C. 1997. Response of dairy cows treated with bovine somatotropin to a luteolytic dose of prostaglandin F2 . Journal ofDairy Science 80:286–294.Google Scholar
Kitwood, S.E., Phillips, C.J.C., and Weise, M. 1993. Use of a vaginal mucus impedance meter to detect estrus in the cow. Theriogenology 40:559–569.Google Scholar
Klemm, W.R., Rivard, G.F., and Clement, B.A. 1994. Blood acetaldehyde fluctuates markedly during bovine estrous cycle. Animal Reproduction Science 35:9–26.Google Scholar
Koelsch, R.K., Aneshansley, D.J., and Butler, W.R. 1994a. Analysis of activity measurement for accurate oestrus detection in dairy cattle. Journal ofAgriculture Engineering Research 58:107–114.Google Scholar
Koelsch, R.K., Aneshansley, D.J., and Butler, W.R. 1994b. Milk progesterone sensor for application in dairy cattle. Journal of Agriculture Engineering Research 58:115–120.Google Scholar
Kunzler, R.A., Clark, D.H., and Marcinkowski, D.P. 1992. Changes in vulvar and vestibular tissue of the bovine during the estrous cycle as determined by the use of near-infrared interactance. Theriogenology 38:935–944.CrossRefGoogle ScholarPubMed
Kyle, B.L., Kennedy, A.D., and Small, J.A. 1998. Measurement of vaginal temperature by radiotelemetry for the prediction of estrus in beef cows. Theriogenology 49:1437–1449.Google Scholar
Lane, A.J.P. and Wathes, D.C. 1998. An electronic nose to detect changes in perineal odors associated with estrus in the cows. Journal of Dairy Science 81:2145–2150.CrossRefGoogle Scholar
Lefebvre, D.M. and Block, E. 1992. Effect of recombinant bovine somatotropin on estradiol-induced estrous behavior in ovariectomized heifers. Journal of Dairy Science 75:1461–1464.Google Scholar
Lehrer, A.R., Lewis, G.S., and Aizinbud, E. 1992. Oestrus detection in cattle: recent developments. Animal Reproduction Science 28:355–361.Google Scholar
Lehrer, A.R., Lewis, G.S., McMillan, W.H., and Aizibud, E. 1995. Bio-impedance monitoring of genital tissues of cows as an aid in cattle reproductive management- a review. New Zealand Society of Animal Production 55:221–225.Google Scholar
Lewis, G.S., Aizinbud, E., and Lehrer, A.R. 1989. Changes in electrical resistance of vulvar tissue in Holstein cows during ovarian cycles and after treatment with prostaglandin F2 . Animal Reproduction Science 18:183–197.Google Scholar
Lewis, G.S. and Newman, S.K. 1984. Changes throughout estrous cycles of variables that might indicate estrus in dairy cows. Journal of Dairy Science 67:146–152.Google Scholar
Maatje, K., de Mol, R.M., and Rossing, W. 1997a. Cow status monitoring (health and oestrus) using detection sensors. Computers and Electronics in Agriculture. 16:245–254.Google Scholar
Maatje, K., Loeffler, S.H., and Engel, B. 1997b. Predicting optimal time of insemination in cows that show visual signs of estrus by estimating onset of estrus with pedometers. Journal of Dairy Science 80:1098–1105.Google Scholar
Macmillan, K.L., and Curnow, R.J. 1977. Tail painting - a simple form of oestrus detection in New Zealand dairy herds. New Zealand Journal of Experimental Agriculture 5:357–361.Google Scholar
Martin, T.E., Henricks, D.M., Hill, J.R. Jr., and Rawlings, N.C.. 1978. Active immunization of the cow against oestradiol-17β. Journal of Reproduction and Fertility 53:173–178.Google Scholar
McLeod, B.J., Foulkes, J.A., Williams, M.E., and Weller, R.F. 1991. Predicting the time of ovulation in dairy cows using on-farm progesterone kits. Animal Production 52:1–9.Google Scholar
Mills, P.A., inventor. 1988. Device for automated detection of estrus in farm animals. Data Sciences, Inc. Roseville, MN. U.S. PatentNo. 4,784,155.Google Scholar
Mitchell, R.S., Sherlock, R.A., and Smith, L.A. 1996. An investigation into the use of machine learning for determining oestrus in cows. Computers and Electronics in Agriculture 15:195–213.Google Scholar
Moore, A.S. and Spahr, S.L. 1991. Activity monitoring and an enzyme immunoassay for milk progesterone to aid in the detection of estrus. Journal of Dairy Science 74:3857–3862.CrossRefGoogle Scholar
Morbeck, D.E., Britt, J.H., and McDaniel, B.T. 1991. Relationships among milk yield, metabolism, reproductive performance of primiparous Holstein cows treated with somatotropin. Journal of Dairy Science 74:2153–2164.Google Scholar
Mortimer, R.G., Salman, M.D., Gutierrez, M. and Olson, J.D. 1990. Effects of androgenizing dairy heifers with ear implants containing testosterone and estrogen on detection of estrus. Journal of Dairy Science 73:1773–1778.Google Scholar
Nebel, R.L. 1988. On-farm milk progesterone tests. Journal of Dairy Science 71:1682–1690.Google Scholar
Nebel, R.L., and Stallings, C.C. 1990. You can have high milk and good reproduction. Hoard=s Dairyman 135:105.Google Scholar
Nebel, R.L., Walker, W.L., Kosek, C.L., and Pandolfi, S.M. 1995. Integration of an electronic pressure sensing system for the detection of estrus into daily reproductive management. Journal of Dairy Science 78(Suppl. 1):225 (Abstr.).Google Scholar
Nebel, R.L., Walker, W.L., McGilliard, M.L., Allen, C.H., and Heckman, G.S. 1994. Timing of artificial insemination of dairy cows: Fixed time once daily versus morning and afternoon. Journal of Dairy Science 77:3185–3191.Google Scholar
Nix, J.P., Spitzer, J.C., and Chenoweth, P.J. 1998. Serum testosterone concentration, efficiency of estrus detection and libido expression in androgenized beef cows. Theriogenology 49:1195–1207.Google Scholar
Pecsok, S.R., McGilliard, M.L., and Nebel, R.L. 1994. Conception rates. 1.Derivation and estimation for effects of estrus detection on cow profitability. Journal of Dairy Science 77:3008–3015.Google Scholar
Pennington, J.A., Albright, J.L., and Callahan, C.J. 1986. Relationships of sexual activities in estrous cows to different frequencies of observation and pedometer measurements. Journal of Dairy Science 69:2925–2934.Google Scholar
Pennington, J.A., Albright, J.L., Diekman, M.A., and Callahan, C.J. 1985. Sexual activity of Holstein cows: seasonal effects. Journal of Dairy Science 68:3023–3030.Google Scholar
Pennington, J.A. and Callahan, C.J. 1986. Use of mount detectors plus chalk as an estrous detection aid for dairy cattle. Journal of Dairy Science 69:248–252.Google Scholar
Peter, A.T. and Bosu, W.T.K. 1986. Postpartum ovarian activity in dairy cows: correlation between behavioral estrus, pedometer measurements and ovulations. Theriogenology 26:111–115.Google Scholar
Pollock, W.E. and Hurnik, J.F. 1979. Effect of two confinement systems on estrous and diestrous behavior in dairy cows. Canadian Journal of Animal Science 59:799–80350.CrossRefGoogle Scholar
Pursley, J.R., Kosorok, M.S., and Wiltbank, M.C. 1997a. Reproductive management of lactating dairy cows using synchronization of ovulation. Journal of Dairy Science 80:301–306.Google Scholar
Pursley, J.R., Wiltbank, M.C., Stevenson, J.S., Ottobre, J.S., Garverick, H.A., and Anderson, L.L.. 1997b. Pregnancy rates per artificial insemination for cows and heifers inseminated at a synchronized ovulation or synchronized estrus. Journal of Dairy Science 80:295–300.Google Scholar
Redden, K.D., Kennedy, A.D., Ingalls, J.R., and Gilson, T.L. 1993. Detection of estrus by radiotelemetric monitoring of vaginal and ear skin temperature and pedometer measurement of activity. Journal of Dairy Science 76:713–721.Google Scholar
Reimers, T.J., Smith, R.D., and Newman, S.K. 1985. Management factors affecting reproductive performance of dairy cows in the northeastern United States. Journal of Dairy Science 68:963–972..Google Scholar
Rodrian, J.D., inventor. 1981. Animal identification and estrus detection system. U.S. Patent No. 4,247,758.Google Scholar
Rodrian, J.D., inventor. 1984. Self-contained estrous detection tag. U.S. Patent No. 4,455,610.Google Scholar
Rodtian, P., King, G.J., Subrod, S., and Pongpiachan, P. 1996. Oestrous behaviour of Holstein cows during cooler and hotter tropical seasons. Animal Reproduction Science 45:47–58.Google Scholar
Sawyer, G.J., Russell-Brown, I.D., and Silcock, J.K. 1986. A comparison of three methods of oestrus detection in commercial dairy herds verified by serum progesterone analysis. Animal Reproduction Science 10:1–10.Google Scholar
Schlünsen, D., Roth, H., Schön, H., Paul, W., and Speckman, H. 1987. Automatic health and oestrus control in dairy husbandry through computer aided systems. Journal of Agriculture Engineering Research 38:263–279.Google Scholar
Senger, P.L. 1994. The estrus detection problem: New concepts, technologies, and possibilities. Journal of Dairy Science 77:2745–2753.Google Scholar
Shipka, M.P. and Ellis, L.C. 1998. No effects of bull exposure on expression of estrous behavior in high-producing dairy cows. Applied Animal Behaviour Science 57:1–7.Google Scholar
Shipka, M.P. and Ellis, L.C. 1999. Effects of bull exposure on postpartum ovarian activity of dairy cows. Animal Reproduction Science 54:237–244.Google Scholar
Smith, J.W., Spahr, S.L., and Puckett, H.B. 1989. Electrical conductivity of reproductive tissue for detection of estrus in dairy cows. Journal of Dairy Science 72:693–701.Google Scholar
Spicer, L.J., Tucker, W.B., and Adams, G.D. 1990. Insulin-like growth factor-I in dairy cows: Relationships among energy balance, body condition, ovarian activity, and estrous behavior. Journal of Dairy Science 73:929–937.Google Scholar
Sprecher, D.J., Farmer, J.A., Nebel, R.L., and Mather, E.C. 1995. The educational implications of reproductive problems identified during investigations at Michigan dairy farms. Theriogenology 43:373–380.Google Scholar
Staples, C.R, Thatcher, W.W., and Clark, J.H. 1990. Relationship between ovarian activity and energy status during the early postpartum period of high producing dairy cows. Journal of Dairy Science. 73:938–947.Google Scholar
Starzl, T.W., Cattell, M., Mihran, R.T., and Zapp, L.M., inventors. 1996. Heat detection for animals including cows. DDx Inc., Boulder, Co. U.S. Patent No. 5,542,431.Google Scholar
Stevenson, J.S. 1999. Can you have good reproduction and high milk yield? Hoard's Dairyman 144:536.Google Scholar
Stevenson, J.S., and Britt, J.H. 1977. Detection of estrus by three methods. Journal of Dairy Science 60:1994–1998.Google Scholar
Stevenson, J.S., Kobayashi, Y., Shipka, M.P., and Rauchholz, K.C. 1996a. Altering conception of dairy cattle by gonadotropin-releasing hormone preceding luteolysis induced by prostaglandin F2 . Journal of Dairy Science 79:402–410.Google Scholar
Stevenson, J.S., Kobayashi, Y., and Thompson, K.E. 1999. Reproductive performance of dairy cows in various programmed breeding systems including Ovsynch and combinations of gonadotropin-releasing hormone and prostaglandin F2. Journal of Dairy Science 82:506.515.Google Scholar
Stevenson, J.S., Lamb, G.C., Hoffman, D.P., and Minton, J.E. 1997. Interrelationships of lactation and postpartum anovulation in suckled and milked cows. Livestock Production Science 50:57–74.CrossRefGoogle Scholar
Stevenson, J.S., Lamb, G.C., Kobayashi, Y., and Hoffman, D.P. 1998. Luteolysis during two stages of the estrous cycle: Subsequent endocrine profiles associated with radiotelemetrically detected estrus in heifers.Journal of Dairy Science 81:2897–2903.CrossRefGoogle Scholar
Stevenson, J.S., and Phatak, A.P. 1999. Effective use of heat detection devices. Large Animal Practice 20:28–31.Google Scholar
Stevenson, J.S., Schmidt, M.K., and Call, E.P. 1983. Estrous intensity and conception rates in Holsteins. Journal of Dairy Science 66:275–280.Google Scholar
Stevenson, J.S., Smith, M.W., Jaeger, J.R., Corah, L.R., and LeFever, D.G. 1996b. Detection of estrus by visual observation and radiotelemetry in peripubertal, estrus-synchronized beef heifers. Journal of Animal Science 74:729–735.Google Scholar
Stewart, R.E., Stevenson, J.S., Mee, M.O., Rettmer, I., and Schneider, J.E. 1993. Induction of estrus after thyroidectomy in nonlactating Holstein cows. Journal of Dairy Science 76:2619–2623.Google Scholar
Stoebel, D.P., and Moberg, G.P. 1982. Effect of adrenocorticotropin and Cortisol on luteinizing hormone surge and estrous behavior of cows. Journal of Dairy Science 65:1016–1024.Google Scholar
Uebe, R, and Stein, M., inventors. 1993. Method of processing data for determining the time of ovulation in an animal, Uebe-Thermometer GmbH, Wertheim-Reicholzheim, Germany. U.S. Patent No. 5,216,599.Google Scholar
Vailes, L.D. and Britt, J.H. 1990. Influence of footing surface on mounting and other sexual behaviors of estrual Holstein cows. Journal of Animal Science 68:2333–2339.Google Scholar
Vailes, L.D., Washburn, S.P., and Britt, J.H. 1992. Effects of various steroid milieus or physiological states on sexual behavior of Holstein cows. Journal of Animal Science 70:2094–2103.Google Scholar
Van Vliet, J.H. and Van Eerdenburg, F.J.C.M. 1996. Sexual activities and oestrus detection in lactating Holstein cows. Applied Animal Behaviour Science 50:57–69.Google Scholar
Villa-Godoy, A., Hughes, T.L., Emery, R.S., Stanisiewski, E.P., and Fogwell, R.L. 1990. Influence of energy balance and body condition on estrus and estrous cycles in Holstein heifers. Journal of Dairy Science 73:2759–2765.Google Scholar
Walker, W.L., Nebel, R.L., and McGilliard, . 1996. Time of ovulation relative to mounting activity in dairy cattle. Journal of Dairy Science 79:1555–1561.Google Scholar
Walton, J.S. and King, G.J. 1986. Indicators of estrus in Holstein cows housed in tie stalls. Journal of Dairy Science 69:2966–2973.Google Scholar
Walton, J.S., Veenhuizin, L.P., and King, G.J. 1987. Relationships between time of day, estrous behavior, and the preovulatory luteinizing hormone surge in Holstein cows after treatment with cloprostenol. Journal ofDairy Science 70:1652–1663.Google Scholar
Waterman, D.F., Silvia, W.J., Hemken, R.W., Heersche, G. Jr., Swenson, T.S., and Eggert, R.G. 1993. Effect of bovine somatotropin on reproductive function in lactating dairy cows. Theriogenology 40:1015–1028.Google Scholar
Webb, R., Gosden, R.G., Telfer, E.E., and Moor, R.M. 1999. Factors affecting folliculogenesis in ruminants. Animal Science 68:257–284.Google Scholar
Weidong, M.A., Clement, B.A., and Klemm, W.R. 1995. Cyclic changes in volatile constituents of bovine vaginal secretions. Journal of Chemical Ecology 21:1895–1905.Google Scholar
Williams, W.F., Yver, D.R., and Gross, T.S. 1981. Comparison of estrus detection techniques in dairy heifers. Journal ofDairy Science 64:1738–1741.Google Scholar
Williamson, N.B., Morris, R.S., Blood, D.C., and Cannon, C.M. 1972a. A study of oestrous behaviour and oestrus detection methods in a large commercial dairy herd. I. The relative efficiency of method of oestrus detection. Veterinary Record 91:50–58.Google Scholar
Williamson, N.B., Morris, R.S., Blood, D.C., and Cannon, C.M. 1972b. A study of oestrous behaviour and oestrus detection methods in a large commercial dairy herd. II. Oestrous signs and behaviour patterns. Veterinary Record 91.58–62.Google Scholar
Wolfenson, D., Flamenbaum, I., and Berman, A. 1988. Hyperthermia and body energy store effects on estrous behavior, conception rate, and corpus luteum function in dairy cows. Journal ofDairy Science 71:3497–3504.Google ScholarPubMed
Xu, Z.Z., McKnight, D.J., Vishwanath, R., Pitt, C.J., and Burton, L.J. 1997. Estrus detection using radiotelemetry or visual observation and tail painting for dairy cows on pasture. Journal ofDairy Science 81:2890–2896.Google Scholar