36:
756:, since coitus induces ovulation. However, various incidents of spontaneous ovulation have been documented in the domestic cat and various non-domestic species. Without ovulation, she may enter interestrus, which is the combined stages of diestrus and anestrus, before reentering estrus. With the induction of ovulation, the female becomes pregnant or undergoes a non-pregnant
822:
anestrous, and do not become fertile. As the days grow longer, the longer periods of daylight cause the hormones that activate the breeding cycle to be released. As it happens, this benefits these animals in that, given a gestation period of about eleven months, it prevents them from having young when the cold of winter would make their survival risky.
783:
dogs bleed during estrus, which usually lasts from 7–13 days, depending on the size and maturity of the dog. Ovulation occurs 24–48 hours after the luteinizing hormone peak, which occurs around the fourth day of estrus; therefore, this is the best time to begin breeding. Proestrus bleeding in dogs is common and is believed to be caused by
857:
grow to a maximal volume, achieved within 24 hours of ovulation. They remain at that size for three days, halve in size before the metestrus of the next cycle and then shrink abruptly before estrus of the cycle after that. Thus the ovaries of cycling rats contain three different sets of corpora lutea
821:
cycle of horses and other large herd animals is that it is usually affected by the seasons. The number of hours daily that light enters the eye of the animal affects the brain, which governs the release of certain precursors and hormones. When daylight hours are few, these animals "shut down", become
734:
Generally speaking, the timing of estrus is coordinated with seasonal availability of food and other circumstances such as migration, predation etc., the goal being to maximize the offspring's chances of survival. Some species are able to modify their estral timing in response to external conditions.
830:
Rats are polyestrous animals that typically have rapid cycle lengths of 4 to 5 days. Although they ovulate spontaneously, they do not develop a fully functioning corpus luteum unless they receive coital stimulation. Fertile mating leads to pregnancy in this way, but infertile mating leads to a state
782:
is usually diestrous (goes into heat typically twice per year), although some breeds typically have one or three cycles per year. The proestrus is relatively long at 5 to 9 days, while the estrus may last 4 to 13 days, with a diestrus of 60 days followed by about 90 to 150 days of anestrus. Female
909:
Due to the widespread use of bovine animals in agriculture, cattle estrous cycles have been widely studied, and manipulated, in an effort to maximize profitability through reproductive management. Much estrous control in cattle is for the purpose of synchronization, a practice or set of practices
924:: There are currently five available gonadorelin products that are FDA-Approved. Usually, gonadorelin is used in conjunction with another estrous control drug (typically, prostaglandin). This drug is used to mimic gonadotropin releasing hormone (GnRH) and may also be used to treat ovarian cysts.
874:
has been found to be 1.23±0.22g (metestrus), 3.15±0.10g (early diestrus), 2.25±0.32g (late diestrus), and 1.89±0.31g (proestrus/estrus), respectively. The plasma progesterone concentration was 1.68±0.37, 4.29±0.22, 3.89±0.33, and 0.34±0.14 ng/ml while mean vascular density (mean number of
895:, or attempting to mount other animals. While visual and behavioral cues are helpful to the male cattle, estrous stages cannot be determined by the human eye. Rather, the stage can be estimated from the appearance of the corpora lutea or follicle composition.
834:
A set of follicles starts to develop near the end of proestrus and grows at a nearly constant rate until the beginning of the subsequent estrus when the growth rates accelerate eightfold. Ovulation occurs about 109 hours after the start of follicle growth.
466:
mature and estrogen secretions exert their biggest influence. The female then exhibits sexually receptive behavior, a situation that may be signaled by visible physiologic changes. Estrus is commonly seen in the mammalian species, including some primates.
955:
has been linked to impairment of follicular development, especially impactful to the first-wave dominant follicle. Future synchronization programs are planning to focus on the impact of heat stress on fertilization and embryonic death rates after
887:" in agriculture, will gradually enter standing estrus, or "standing heat," starting at puberty between 9 and 15 months of age. The cow estrous cycle typically lasts 21 days. Standing estrus is a visual cue which signifies sexual receptivity for
142:. Many mammals used in commercial agriculture, such as cattle and sheep, may have their estrous cycles artificially controlled with hormonal medications for optimum productivity. The male equivalent, seen primarily in ruminants, is called
813:
may be in heat for 4 to 10 days, followed by approximately 14 days in diestrus. Thus, a cycle may be short, totaling approximately 3 weeks. Horses mate in spring and summer; autumn is a transition time, and anestrus occurs during winter.
385:
588:, chronic energy deficit, and possibly age. Chronic exposure to anabolic steroids may also induce a persistent anestrus due to negative feedback on the hypothalamus/pituitary/gonadal axis. Other spellings include
406:
start to grow. Their number is species-specific. Typically, this phase can last as little as one day or as long as three weeks, depending on the species. Under the influence of estrogen, the lining of the uterus
138:. Typically, estrous cycles repeat until death. These cycles are widely variable in duration and frequency depending on the species. Some animals may display bloody vaginal discharge, often mistaken for
963:
Additionally, work has been done regarding other mammalian females, such as in dogs, for estrous control; However, there are yet to be any approved medications outside of those commercially available.
1164:
930:: Mimics the prostaglandin F2-alpha hormone released when no pregnancy has occurred and regresses the corpus luteum. This drug is used to achieve more consistent results in artificial insemination.
875:
vessels/10 microscopic fields at 400x) in corpus luteum was 6.33±0.99, 18.00±0.86, 11.50±0.76, and 2.83±0.60 during the metestrus, early diestrus, late diestrus and proestrus/estrus, respectively.
891:
by male cattle. This behavior lasts anywhere between 8 and 30 hours at a time. Other behaviors of the female during standing estrus may change, including, but not limited to: nervousness, swollen
619:
Estrous cycle variability differs among species, but cycles are typically more frequent in smaller animals. Even within species significant variability can be observed, thus
226:(i.e., the ability to become pregnant). Some species of animals with estrous cycles have unmistakable outward displays of receptivity, ranging from engorged and colorful
568:. Melatonin may repress stimulation of reproduction in long-day breeders and stimulate reproduction in short-day breeders. Melatonin is thought to act by regulating the
913:
There is variation between the available methods of cattle estrous synchronization. Treatment depends on herd size, specific goals for control, and budget. Some of the
866:
Buffalo have an estrous cycle of about 22 to 24 days. Buffalo are known for difficult estrus detection. This is one major reason for being less productive than
57:
940:, which used in controlling menstrual periods. It is also available as a medicated feed, but this method is not yet approved for cattle crop synchronization.
944:
There is variation between the available methods of cattle estrous synchronization. Treatment depends on herd size, specific goals for control, and budget.
831:
of pseudopregnancy lasting about 10 days. Mice and hamsters have similar behavior. The events of the cycle are strongly influenced by lighting periodicity.
1643:
Qureshi, A. S.; Hussain, M.; Rehan, S.; Akbar, Z.; Rehman, N. U. (2015). "Morphometric and angiogenic changes in the corpus luteum of nili-ravi buffalo (
623:
may undergo an estrous cycle of 3 to 7 weeks. Domestication can affect estrous cycles due to changes in the environment. For most species, vaginal smear
1830:
853:, and ovulation occurs at about 4 am on the next estrus day. The following day, metestrus, is called early diestrus or diestrus I. During this day, the
2101:
1944:
2056:
Pelican, K.; Wildt, D.; Pukazhenthi, B.; Howard, J. G. (2006). "Ovarian control for assisted reproduction in the domestic cat and wild felids".
1353:
1785:
1628:
Yoshinaga, K. (1973). "Gonadotrophin-induced hormone secretion and structural changes in the ovary during the nonpregnant reproductive cycle".
1495:
Walter, I.; Galabova, G.; Dimov, D.; Helmreich, M. (February 2011). "The morphological basis of proestrus endometrial bleeding in canines".
411:) starts to develop. Some animals may experience vaginal secretions that could be bloody. The female is not yet sexually receptive; the old
270:(literally 'gadfly', more figuratively 'frenzy', 'madness', among other meanings like 'breeze'). Specifically, this refers to the gadfly in
560:
Anestrus refers to the phase when the sexual cycle rests. This is typically a seasonal event and controlled by light exposure through the
917:-approved drugs and devices used to mimic natural hormones of the estrous cycle include, but are not limited to, the following classes:
1033:
1335:
44:
936:: Used to suppress estrus and/or block ovulation. Most commonly, it is administered via an intravaginal insert comparable to an
101:
655:
have more than one estrous cycle during a specific time of the year and can be divided into short-day and long-day breeders:
607:, which is ovulation and corpus luteum production that occurs immediately following the birth of the young. For example, the
528:
of the corpus luteum. The lining in the uterus is not shed, but is reorganized for the next cycle. Other spellings include
1315:
1246:
Freeman, Marc E. (1994). "The
Neuroendocrine control of the ovarian cycle of the rat". In Knobil, E.; Neill, J. D. (eds.).
415:
degenerates; the uterus and the vagina distend and fill with fluid, become contractile and secrete a sanguinous fluid; the
1895:
Wolfenson, D.; Thatcher, W. W.; Badinga, L.; Savi0, J. D.; Meidan, R.; Lew, B. J.; Braw-tal, R.; Berman, A. (1995-05-01).
419:
proliferates and the vaginal cytology shows a large number of non-cornified nucleated epithelial cells. Variant terms for
2106:
1128:
2144:
2091:
1165:"The Cattle Estrous Cycle and FDA-Approved Animal Drugs to Control and Synchronize Estrus—A Resource for Producers"
489:
1451:
384:
203:
if conception does not occur during that cycle. Mammals that have menstrual cycles shed the endometrium through
573:
165:
333:
The earliest use in
English was with a meaning of 'frenzied passion'. In 1900, it was first used to describe '
2000:
Kutzler MA. Estrous Cycle
Manipulation in Dogs. Vet Clin North Am Small Anim Pract. 2018 Jul;48(4):581-594.
2139:
2118:
1428:
1261:
Heape, W. (1900). "The 'sexual season' of mammals and the relation of the 'pro-oestrum' to menstruation'".
1043:
914:
850:
334:
173:
143:
310:"driven and drawn by the gadfly of desire". Somewhat more closely aligned to current meaning and usage of
728:
1672:
1581:
1071:
1959:
1531:
1897:"Effect of Heat Stress on Follicular Development during the Estrous Cycle in Lactating Dairy Cattle1"
1593:
McCracken, J. A.; Custer, E. E.; Lamsa, J. C. (1999). "Luteolysis: A neuroendocrine-mediated event".
1085:
Bronson, F. H., 1989. Mammalian
Reproductive Biology. University of Chicago Press, Chicago, IL, USA.
2023:"Circannual variations in intraovarian oocyte but not epididymal sperm quality in the domestic cat"
155:
1960:"The effect of embryonic death rates in cattle on the efficacy of estrus synchronization programs"
1806:
2149:
1966:. Research and Practice III. 15th International Congress on Animal Reproduction. 82–83: 513–535.
957:
904:
784:
377:
271:
49:
1695:"Accuracy of Predicting Stages of Bovine Estrous Cycle by Gross Appearance of the Corpus Luteum"
1096:
910:
most often used by cattle farmers to control the timing and duration of estrus in large herds.
651:, meaning that they can go into heat several times per year. Seasonally polyestrous animals or
361:
94:
1938:
1282:"Ovulatory cycle effects on tip earnings by lap dancers: Economic evidence for human estrus?"
1229:
525:
204:
139:
841:
peaks at about 11 am on the day of proestrus. Between then and midnight there is a surge in
134:
in females and are interrupted by anestrous phases, otherwise known as "rest" phases, or by
1332:
1281:
888:
115:
1958:
Santos, J. E. P; Thatcher, W. W; Chebel, R. C; Cerri, R. L. A; Galvão, K. N (2004-07-01).
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1744:"Composition and characteristics of follicular waves during the bovine estrous cycle"
1724:
1716:
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764:. Cats are polyestrous but experience a seasonal anestrus in autumn and late winter.
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has a fertile postpartum estrus that occurs 14 to 24 hours following parturition.
1380:"Determination of the oestrous cycle phases of rats: some helpful considerations"
1339:
1202:
1048:
761:
713:
521:
508:, which produces progesterone. The signs of estrogen stimulation subside and the
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2039:
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2005:
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82:
731:
by the act of mating and are able to conceive at almost any arbitrary moment.
390:
A four-phase terminology is used in reference to animals with estrous cycles.
2133:
1979:
1922:
1881:
1767:
1720:
1555:
1405:
1018:
947:
Bovine estrous cycles may also be impacted by other bodily functions such as
927:
871:
854:
509:
505:
412:
20:
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in heat has an estrus of 14 to 21 days and is generally characterized as an
2077:
2048:
1987:
1614:
1563:
1516:
1413:
952:
884:
842:
810:
757:
644:
624:
569:
561:
459:
189:
161:
1930:
1728:
921:
408:
364:, a mammal may be described as "in estrus" when it is in that particular
231:
200:
181:
1129:"Synchronizing Estrus in Cattle - How does estrus synchronization work?"
2111:
479:
196:
114: 'gadfly') is a set of recurring physiological changes induced by
1582:
https://embryology.med.unsw.edu.au/embryology/index.php/Estrous_Cycle
1072:
https://embryology.med.unsw.edu.au/embryology/index.php/Estrous_Cycle
1028:
933:
818:
792:
717:
627:
may be used in order to identify estrous cycle phases and durations.
581:
565:
493:
475:
315:
291:
223:
160:
Mammals share the same reproductive system, including the regulatory
107:
218:
rather than estrous cycles. Humans, unlike most other species, have
1426:
999:
948:
838:
672:
227:
222:, a lack of obvious external signs to signal estral receptivity at
185:
1361:
Compendium on
Continuing Education for the Practicing Veterinarian
1831:"Hormonal Control of Estrus in Cattle - Management and Nutrition"
1187:
705:
683:
603:
After completion (or abortion) of a pregnancy, some species have
585:
306:
also used it to refer to an irrational drive and to describe the
1378:
Marcondes, F. K.; Bianchi, F. J.; Tanno, A. P. (November 2002).
35:
1182:
993:
867:
724:
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during the warm season to aid survival during the next winter.
687:
513:
486:, in which the animal spontaneously elevates her hindquarters.
258:
127:
123:
119:
2055:
1894:
1429:"Estrous cycles, copulation and pregnancy in the fennec fox (
1023:
975:
892:
679:
660:
608:
471:
403:
303:
299:
262:
1494:
450:
refers to the phase when the female is sexually receptive ("
1452:
10.1644/1545-1542(2002)083<0099:ECCAPI>2.0.CO;2
1005:
987:
709:
668:
664:
307:
287:
275:
16:
Ovulation cycle occurring in most mammalian therian females
870:. During four phases of its estrous cycle, mean weight of
1957:
1742:
Ginther, O. J.; Kastelic, J. P.; Knopf, L. (1989-09-01).
981:
779:
749:
640:
636:
620:
283:
1693:
Ireland, James J.; Murphee, R.L.; Coulson, P.B. (1980).
1642:
149:
1856:"Alteration of the Bovine Estrous Cycle with Oxytocin"
1692:
1427:
Valdespino, C.; Asa, C.S. & Bauman, J.E. (2002).
1377:
716:
per year, typically in spring to allow growth of the
478:
may occur spontaneously in others. Especially among
1741:
1592:
1342:
citing: Stedman's
Medical Dictionary. Copyright 2006
504:This phase is characterized by the activity of the
971:Estrus frequencies of some other notable mammals:
791:from the blood vessels due to the increase of the
1786:"Fertagyl® (gonadorelin acetate) - Veterinarians"
1538:. Special Issue: Reproductive Cycles of Animals.
19:For the biological genus name of the gadfly, see
2131:
1853:
1241:
1239:
298:to indicate 'frenzy', and to describe madness.
1784:Medicine, Center for Veterinary (2018-11-03).
1671:Perry, George (2004). Salverson, Robin (ed.).
1163:Medicine, Center for Veterinary (2021-03-05).
727:, do not have an estrous cycle, instead being
2020:
1273:
694:Species that go into heat twice per year are
376:"Estrus" redirects here. For other uses, see
352:. In all English spellings, the noun ends in
237:
1236:
1943:: CS1 maint: numeric names: authors list (
1807:"LUTALYSE® Injection (dinoprost injection)"
516:lining begins to appear. In the absence of
458:" in British English). Under regulation by
247:
1263:Quarterly Journal of Microscopical Science
1250:. Vol. 2 (2nd ed.). Raven Press.
1094:
1034:Progesterone-releasing intravaginal device
195:However, animals that have estrous cycles
2038:
1912:
1871:
1854:Armstrong, D.T.; Hansel, William (1959).
1710:
1649:Pakistan Journal of Agricultural Sciences
1627:
1395:
690:are sexually active in spring and summer.
1783:
1162:
1133:Texas A&M AgriLife Extension Service
499:
156:Menstrual cycle § Cycles and phases
60:of all important aspects of the article.
1576:Hill, M.A. (2021, March 11) Embryology
1351:
1245:
1066:Hill, M. A. (2021, April 6) Embryology
576:. Anestrus is induced by time of year,
2132:
2116:
2021:Spindler, R. E.; Wildt, D. E. (1999).
1529:
1333:medilexicon.com > postpartum estrus
1279:
675:are sexually active in fall or winter.
56:Please consider expanding the lead to
1801:
1799:
1779:
1777:
1670:
1666:
1664:
1662:
1632:. Vol. Endocrinology II, Part 1.
1260:
1158:
1156:
1154:
1152:
1150:
1148:
1123:
1121:
1119:
1117:
180:, and the ovary itself that releases
2117:Skloot, Rebecca (December 9, 2007).
2070:10.1016/j.theriogenology.2006.03.013
1509:10.1016/j.theriogenology.2010.04.022
1081:
1079:
883:Female cattle, also referred to as "
858:at different phases of development.
614:
150:Differences from the menstrual cycle
93: 'frenzy', originally from
29:
1354:"Prolific Cats: The Oestrous Cycle"
1095:Llera, Ryan; Yuill, Cheryl (2021).
738:
496:for the synchronization of estrus.
13:
2014:
2008:. Epub 2018 Apr 27. PMID 29709316.
1796:
1774:
1659:
1301:10.1016/j.evolhumbehav.2007.06.002
1145:
1114:
898:
520:, the diestrus phase (also termed
482:, a signal trait of estrus is the
326:to describe the desire of fish to
14:
2161:
2085:
1972:10.1016/j.anireprosci.2004.04.015
1873:10.3168/jds.s0022-0302(59)90607-1
1712:10.3168/jds.s0022-0302(80)82901-8
1548:10.1016/j.anireprosci.2011.02.005
1352:Griffin, Brenda (December 2001).
1076:
723:A few mammalian species, such as
302:used the word to describe panic.
1530:Aurich, Christine (2011-04-01).
1313:
490:Controlled internal drug release
383:
365:
34:
1994:
1951:
1888:
1847:
1823:
1735:
1686:
1636:
1621:
1586:
1570:
1532:"Reproductive cycles of horses"
1523:
1488:
1479:
1466:
1420:
1397:10.1590/S1519-69842002000400008
1371:
1345:
1326:
1307:
1280:Miller, Geoffrey (April 2007).
1254:
214:, and a few other species have
48:may be too short to adequately
1248:The Physiology of Reproduction
1221:
1209:
1194:
1175:
1088:
1060:
574:gonadotropin-releasing hormone
474:becomes swollen and reddened.
371:
166:gonadotropin-releasing hormone
58:provide an accessible overview
1:
1607:10.1152/physrev.1999.79.2.263
1054:
130:. Estrous cycles start after
1760:10.1016/0378-4320(89)90084-5
1384:Brazilian Journal of Biology
1289:Evolution and Human Behavior
1044:Rut (mammalian reproduction)
996:: 13 to 31 days (average 23)
851:follicle-stimulating hormone
659:Short-day breeders, such as
630:
393:
362:Modern International English
174:follicle-stimulating hormone
7:
2123:The New York Times Magazine
1964:Animal Reproduction Science
1914:10.1095/biolreprod52.5.1106
1748:Animal Reproduction Science
1536:Animal Reproduction Science
1316:"Estrus and Mating in Dogs"
1012:
678:Long-day breeders, such as
555:
454:" in American English, or "
230:to behavioral changes like
10:
2166:
2040:10.1095/biolreprod61.1.188
2006:10.1016/j.cvsm.2018.02.006
1673:"The Bovine Estrous Cycle"
902:
802:
771:
375:
282:, who had been won in her
263:
238:Etymology and nomenclature
153:
100:
18:
1647:) during estrous cycle".
966:
878:
798:
698:. Canines are diestrous.
438:
366:part of the estrous-cycle
1860:Journal of Dairy Science
1699:Journal of Dairy Science
1485:Spindler and Wildt, 1999
1097:"Estrous Cycles in Dogs"
861:
23:. For Satyr leader, see
2145:Reproduction in mammals
2027:Biology of Reproduction
1901:Biology of Reproduction
958:artificial insemination
905:Estrous synchronization
825:
767:
743:
378:Estrus (disambiguation)
272:Ancient Greek mythology
1630:Handbook of Physiology
951:levels. Additionally,
635:Some species, such as
572:pulse activity of the
524:) terminates with the
248:
87:
1595:Physiological Reviews
903:Further information:
793:estradiol-17β hormone
500:Metestrus or diestrus
470:In some species, the
460:gonadotropic hormones
356:and the adjective in
245:is derived via Latin
164:system that produces
154:Further information:
116:reproductive hormones
1440:Journal of Mammalogy
512:starts to form. The
492:devices are used in
2140:Mammalian sexuality
2119:"Lap-dance Science"
2107:Horse estrous cycle
2092:Systematic overview
1320:VCA Animal Hospital
847:luteinizing hormone
774:Canine reproduction
337:in animals; heat'.
220:concealed ovulation
178:luteinizing hormone
25:Oestrus (mythology)
2112:Dogs in Heat - FAQ
1338:2016-03-04 at the
1039:Reproductive cycle
805:Horse reproduction
729:induced to ovulate
417:vaginal epithelium
344:, the spelling is
2102:Cat estrous cycle
1835:Veterinary Manual
1580:. Retrieved from
1070:. Retrieved from
817:A feature of the
704:species, such as
653:seasonal breeders
615:Cycle-variability
605:postpartum estrus
464:ovarian follicles
322:, ch. 93.1) uses
75:
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1907:(5): 1106–1113.
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1367:(12): 1049–1056.
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1225:
1219:
1213:
1207:
1198:
1192:
1179:
1173:
1172:
1160:
1143:
1142:
1140:
1139:
1125:
1112:
1111:
1109:
1107:
1092:
1086:
1083:
1074:
1064:
760:, also known as
754:induced ovulator
739:Specific species
712:, have only one
387:
278:sent to torment
266:
265:
251:
216:menstrual cycles
111:
104:
70:
67:
61:
38:
30:
2165:
2164:
2160:
2159:
2158:
2156:
2155:
2154:
2130:
2129:
2088:
2017:
2015:Further reading
2012:
1999:
1995:
1956:
1952:
1936:
1935:
1893:
1889:
1852:
1848:
1839:
1837:
1829:
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1824:
1815:
1813:
1805:
1804:
1797:
1782:
1775:
1740:
1736:
1691:
1687:
1675:
1669:
1660:
1645:Bubalus bubalis
1641:
1637:
1626:
1622:
1591:
1587:
1575:
1571:
1528:
1524:
1493:
1489:
1484:
1480:
1471:
1467:
1435:
1425:
1421:
1390:(4A): 609–614.
1376:
1372:
1356:
1350:
1346:
1340:Wayback Machine
1331:
1327:
1314:Weir, Malcolm.
1312:
1308:
1284:
1278:
1274:
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1244:
1237:
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1222:
1214:
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1199:
1195:
1180:
1176:
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1146:
1137:
1135:
1127:
1126:
1115:
1105:
1103:
1093:
1089:
1084:
1077:
1065:
1061:
1057:
1049:Sexual swelling
1015:
969:
907:
901:
899:Estrous control
881:
864:
828:
807:
801:
789:red blood cells
776:
770:
762:pseudopregnancy
746:
741:
714:breeding season
633:
617:
558:
522:pseudopregnancy
502:
484:lordosis reflex
441:
398:One or several
396:
381:
374:
342:British English
261:'), from Greek
240:
212:elephant shrews
170:pituitary gland
168:in pulses, the
158:
152:
132:sexual maturity
71:
65:
62:
55:
43:This article's
39:
28:
17:
12:
11:
5:
2163:
2153:
2152:
2150:Theriogenology
2147:
2142:
2128:
2127:
2114:
2109:
2104:
2099:
2094:
2087:
2086:External links
2084:
2083:
2082:
2058:Theriogenology
2053:
2033:(1): 188–194.
2016:
2013:
2011:
2010:
1993:
1950:
1887:
1866:(3): 533–542.
1846:
1822:
1795:
1773:
1754:(3): 187–200.
1734:
1705:(1): 155–160.
1685:
1680:SDSU Extension
1658:
1635:
1620:
1601:(2): 263–323.
1585:
1569:
1542:(3): 220–228.
1522:
1503:(3): 411–420.
1497:Theriogenology
1487:
1478:
1465:
1419:
1370:
1344:
1325:
1306:
1295:(6): 375–381.
1272:
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860:
827:
824:
803:Main article:
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772:Main article:
769:
766:
745:
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692:
691:
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632:
629:
616:
613:
584:, significant
564:that releases
557:
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501:
498:
440:
437:
395:
392:
373:
370:
239:
236:
172:that secretes
151:
148:
73:
72:
52:the key points
42:
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15:
9:
6:
4:
3:
2:
2162:
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2143:
2141:
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2124:
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1713:
1708:
1704:
1700:
1696:
1689:
1681:
1674:
1667:
1665:
1663:
1655:(3): 795–800.
1654:
1650:
1646:
1639:
1631:
1624:
1616:
1612:
1608:
1604:
1600:
1596:
1589:
1583:
1579:
1578:Estrous Cycle
1573:
1565:
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1537:
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1506:
1502:
1498:
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1453:
1449:
1446:(1): 99–109.
1445:
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1415:
1411:
1407:
1403:
1398:
1393:
1389:
1385:
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1232:
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1224:
1218:
1212:
1205:
1204:
1197:
1190:
1189:
1184:
1181:Panic of the
1178:
1170:
1166:
1159:
1157:
1155:
1153:
1151:
1149:
1134:
1130:
1124:
1122:
1120:
1118:
1102:
1101:VCA Hospitals
1098:
1091:
1082:
1080:
1073:
1069:
1068:Estrous Cycle
1063:
1059:
1050:
1047:
1045:
1042:
1040:
1037:
1035:
1032:
1030:
1027:
1025:
1022:
1020:
1019:Mating system
1017:
1016:
1007:
1004:
1001:
998:
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989:
986:
983:
980:
977:
974:
973:
972:
964:
961:
959:
954:
950:
945:
939:
935:
932:
929:
928:Prostaglandin
926:
923:
920:
919:
918:
916:
911:
906:
896:
894:
890:
886:
876:
873:
872:corpus luteum
869:
859:
856:
855:corpora lutea
852:
848:
844:
840:
836:
832:
823:
820:
815:
812:
806:
796:
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790:
786:
781:
775:
765:
763:
759:
755:
751:
736:
732:
730:
726:
721:
719:
715:
711:
707:
703:
699:
697:
689:
685:
681:
677:
674:
670:
666:
662:
658:
657:
656:
654:
650:
646:
645:domestic pigs
642:
638:
628:
626:
622:
612:
610:
606:
601:
599:
595:
591:
587:
583:
579:
575:
571:
567:
563:
553:
551:
547:
543:
539:
535:
531:
527:
523:
519:
515:
511:
510:corpus luteum
507:
506:corpus luteum
497:
495:
491:
487:
485:
481:
477:
473:
468:
465:
461:
457:
453:
449:
445:
436:
434:
430:
426:
422:
418:
414:
413:corpus luteum
410:
405:
401:
391:
388:
386:
379:
369:
367:
363:
359:
355:
351:
347:
343:
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336:
331:
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167:
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157:
147:
145:
141:
137:
133:
129:
125:
121:
117:
113:
110:
103:
99:
96:
95:Ancient Greek
92:
91:
90:
84:
80:
79:estrous cycle
69:
59:
53:
51:
46:
41:
37:
32:
31:
26:
22:
21:Oestrus (fly)
2122:
2064:(1): 37–48.
2061:
2057:
2030:
2026:
1996:
1963:
1953:
1939:cite journal
1904:
1900:
1890:
1863:
1859:
1849:
1838:. Retrieved
1834:
1825:
1814:. Retrieved
1810:
1789:
1751:
1747:
1737:
1702:
1698:
1688:
1679:
1652:
1648:
1644:
1638:
1629:
1623:
1598:
1594:
1588:
1577:
1572:
1539:
1535:
1525:
1500:
1496:
1490:
1481:
1473:
1468:
1443:
1439:
1431:Vulpes zerda
1430:
1422:
1387:
1383:
1373:
1364:
1360:
1347:
1328:
1319:
1309:
1292:
1288:
1275:
1266:
1262:
1256:
1247:
1228:
1223:
1217:The Republic
1216:
1211:
1201:
1196:
1186:
1177:
1168:
1136:. Retrieved
1132:
1104:. Retrieved
1100:
1090:
1067:
1062:
970:
962:
946:
943:
912:
908:
882:
865:
843:progesterone
837:
833:
829:
816:
808:
777:
758:luteal phase
747:
733:
722:
701:
700:
695:
693:
648:
634:
618:
604:
602:
597:
593:
589:
570:hypothalamic
562:pineal gland
559:
549:
545:
541:
537:
533:
529:
503:
488:
469:
455:
451:
447:
443:
442:
432:
428:
424:
420:
397:
389:
382:
357:
353:
349:
348:or (rarely)
345:
339:
332:
323:
319:
311:
295:
267:
246:
242:
241:
232:mating calls
209:
205:menstruation
194:
190:progesterone
184:, including
182:sex hormones
162:hypothalamic
159:
140:menstruation
108:
105:
98:
86:
78:
76:
63:
47:
45:lead section
1227:Herodotus,
953:heat stress
922:Gonadorelin
748:The female
649:polyestrous
433:pro-oestrum
425:pro-oestrus
409:endometrium
372:Four phases
201:endometrium
136:pregnancies
2134:Categories
1840:2021-03-22
1816:2021-04-06
1233:, ch. 93.1
1185:in Homer,
1138:2021-03-22
1055:References
1002:: 16 weeks
785:diapedesis
702:Monestrous
538:metoestrum
530:metoestrus
526:regression
480:quadrupeds
360:. Thus in
81:(from
66:March 2021
2097:Etymology
1980:0378-4320
1923:0006-3363
1882:0022-0302
1768:0378-4320
1721:0022-0302
1556:0378-4320
1406:1519-6984
1230:Histories
1191:, book 22
1029:Neutering
990:: 21 days
984:: 21 days
978:: 18 days
934:Progestin
819:fertility
778:A female
718:offspring
696:diestrous
631:Frequency
598:anoestrum
590:anoestrus
582:lactation
578:pregnancy
566:melatonin
550:dioestrum
542:dioestrus
534:metestrum
518:pregnancy
494:livestock
476:Ovulation
429:proestrum
421:proestrus
400:follicles
394:Proestrus
320:Histories
316:Herodotus
292:Euripides
224:ovulation
207:instead.
186:estrogens
126:subclass
124:mammalian
50:summarize
2078:16630653
2049:10377048
1988:15271477
1615:10221982
1564:21377299
1517:21112080
1472:Pelican
1460:51812228
1414:12659010
1336:Archived
1106:April 6,
1013:See also
1008:: 9 days
1000:Elephant
949:oxytocin
889:mounting
839:Estrogen
684:hamsters
625:cytology
594:anestrum
556:Anestrus
546:diestrum
423:include
286:form by
228:genitals
210:Humans,
1931:7626710
1729:7372895
1269:: 1:70.
1215:Plato,
1200:Plato,
1188:Odyssey
1183:suitors
885:heifers
725:rabbits
688:ferrets
586:illness
514:uterine
456:on heat
452:in heat
448:oestrus
402:of the
346:oestrus
324:oîstros
296:oestrus
268:oîstros
264:οἶστρος
249:oestrus
120:females
109:oîstros
102:οἶστρος
89:oestrus
2076:
2047:
1986:
1978:
1929:
1921:
1880:
1766:
1727:
1719:
1613:
1562:
1554:
1515:
1476:, 2006
1474:et al.
1458:
1412:
1404:
1206:, 854b
994:Donkey
967:Others
879:Cattle
868:cattle
799:Horses
706:canids
680:horses
647:, are
596:, and
548:, and
444:Estrus
439:Estrus
431:, and
350:œstrus
312:estrus
284:heifer
259:gadfly
255:frenzy
243:Estrus
197:resorb
128:Theria
1676:(PDF)
1456:S2CID
1436:(PDF)
1357:(PDF)
1285:(PDF)
1024:Musth
976:Sheep
893:vulva
862:Bison
710:bears
665:goats
661:sheep
609:mouse
472:vulva
404:ovary
328:spawn
304:Plato
300:Homer
294:used
274:that
97:
85:
83:Latin
2074:PMID
2045:PMID
1984:PMID
1976:ISSN
1945:link
1927:PMID
1919:ISSN
1878:ISSN
1764:ISSN
1725:PMID
1717:ISSN
1611:PMID
1560:PMID
1552:ISSN
1513:PMID
1410:PMID
1402:ISSN
1203:Laws
1108:2021
1006:Wolf
988:Goat
849:and
826:Rats
811:mare
768:Dogs
744:Cats
708:and
686:and
671:and
669:deer
643:and
641:cows
637:cats
621:cats
358:-ous
308:soul
288:Zeus
276:Hera
257:', '
199:the
188:and
176:and
77:The
2066:doi
2035:doi
2002:doi
1968:doi
1909:doi
1868:doi
1790:FDA
1756:doi
1707:doi
1603:doi
1544:doi
1540:124
1505:doi
1448:doi
1392:doi
1297:doi
1169:FDA
982:Pig
938:IUD
915:FDA
787:of
780:dog
750:cat
673:elk
446:or
354:-us
340:In
335:rut
144:rut
122:of
118:in
2136::
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2060:.
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2029:.
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1982:.
1974:.
1962:.
1941:}}
1937:{{
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
