Synchronization of estrus in cattle for embryo transfer

THERIOGENOLOGY SYNCERONIEATION OF ESTRUS IN CATTLE FOR EMBRYO TRANSFER

P. T. Cuppa

, G. B. Anderson('),K)Drost('),

B. Darien and M. B. Horton (1) Departmentof Animal Science,Universityof California, Davis, CA 95616 (2) Departmentof Reproduction,School of Veterinary Medicine,Universityof California,Davis, CA 95616 Receivedfor Publication: June 20.,1977 ABSTRACT Two groups of donors (31 animals)receiving2,000 to 3,000 IU of PMSG followedby 30 to 33 mg of prostaglandinF2&'BAM salt 48 hours later showed an average intervalto eetrue of 44 + 2.7 and 512 5.7 hours after prostaglandintreatment. Three groups of donors (32 animals)receivingthe above treatmentplus 500 ug estrediol32 to 38 hours after prostaglandinshowed an average intervalto estrus of 50 + 1.0, 36 + 1.6 and'48f 5.2 hours after proetaglandin. One group of recipients(16 animals)receivingprostaglandinduring the mid luteal phase of the cycle showed an average intervalof 78 + 9.2 hours to onset of eatrue while a comparablegroup treatedwith e&radio1 32 hours after proetaglandinhad an average intervalof 52 + 5.0 hours to estrus. One group of recipients(15 animals) treatedwith prostaglandin duringthe late dieatrousor early proestrusphase of the cycle had an average intervalto estrus of 412 3.7 hours and two groups of recipients (27 animals) treatedat the same stages of the cycle and receiving estradiolhad an average intervalto eatrus of 47 + 2.0 and 48 + 5.2 hours, respectively. INTRODUCTION Synchronization of estrus and ovulationbetween donors and recipients is essentialfor optimum fertilityfor the transferof embryos in cattle (1, 2). Several investigators(3, 4, 5) have reported that prostaglandinF2o is luteolyticin cattle and that fertilityis normal at the estrus followingthe regressionof the corpus luteum with the drug. ProstaglandinF2o has been combinedwith eetradiolto increase the incidenceof behavioraleetrus (6) and to improve synchronization of CstNs (7). Hill et al. (8) reported that PGFZa could be combined with PMSG for multiplroclations in cattle. The purpose of these experimentswas to establisha combinationof estrogen,PMSG end PGF2o which would synchronizeestrus in donors and recipientsfor twin embryo transfersin cattle. MATERIALSANDMBTBODS Animals used for these trials were of several differenttypes and were obtainedfrom severaldifferentsources. Group I consistedof 7

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THERIOGENOLOGY Holsteinheifers,5 crossbredHerefordx Red Angus heifers, 13 grade Hereford and grade Angus heifers and 5 Hereford cows. All the Holstein heifers, two of the crossbred,and six of the grade heiferswere used as recipients. The other heifers and the cows were used as donors. All the animalswere checked for cyclic activityand the heifers used as donors received2,000 to 2,500 IU PMSG approximate1 48 hours before 13during the late receiving30 or 33 mg of prostaglandinP2o TRAM salt(a luteal or early proestrualphase of the estrous cycle. The older cows used as donors received3,000 IU PMSG under the ssme regimen used on the heifers. Four of the Holsteinheifers used as recipientswere due in estrus within 4 days at the time of the prostaglandlntreatment. They received15 mg of PGF2u and their responseswere similar to those receiving 30 mg of PGF2o so they are includedin the same group. Some of these.animalswere injectedsubcutaneouslyand some received the hormones intramuscularly.No differencesbetween the route of admininistrationand responsewere noted and all subsequentgroups of animals received the hormones intramuscularly. Group II animalswere Hereford,Angus, or Hereford-Anguscrossbred heifers. PregnantMare Serum Gonadotropinand PGF2u were injectedas in group I and 500 ug of estradiolwere injectedapproximately32 hours after the animals receivedprostaglandln. Groups III, IV and V consistedof grade Hereford,Angus and crossbred heifers. Groups III and IV were treatedduring June and July when they were just reachingpuberty. Donors and recipientswere treated the same with respect to prostaglandinF2u and e&radio1 and donors received the exogenousgonadotropin48 hours before proetaglandlnwas administered, Group III consistedof animals that showed estrus shortly after purchaseor the phase of the eetroua cycle was estimatedon the basis of the size, consistency,and morphologicalcharacteristics of the corpus luteum as determinedby rectal palpation. Group IV consistedof animalswhich had palpablecorpora lutea in which it was not possibleto accuratelyestimate the stage of cycle. These animalswere treated twice. All of them receivedprostaglandln and estradiolon the first treatment(2x-1stin Table I). The donors receivedPI&G on day 17 after the average day of estrous followingthe first treatmentfollowedby.proataglandin 48 hours later (D-2x-2ndin Table I). The recipientswere treatedwith proetaglandlnthe second time (R-2x-2nd)at the same time as the donors (19 days). This regimen was used to determineif it would decrease the normal variationin the length of the eetroua cycle. Group V consistedof animals from groups III and IV which did not respond or could not be used for embryo transferin the trials conducted during June and July. This trial was conductedin November and (a)Courtesyof Dr. J. W. Lauderdaleand J. E. Pike, the Upjohn Company.

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THERIOGENOLOGY Decemberat which time the animalswere older and cyclic data were available. In this trial 16 donors were treatedwith 2,000 IU PMSG on days 6 to 12 of the estrous cycle and 33 mg of PGF2o 48 hours later. The 32 recipients,days 7 to 15 of the estrous cycle, received30 mg PGF2, at the same time as the donors and 16 of them received500 ug estradiol32 hours after prostaglandln. Estrus was detectedin all groups by observationof behaviorand by marking with a non-entryteaser bull. Animals were checked for estrus between 7 and 9 am, 4 and 7 pm daily. RESULTSAND DISCUSSION The animals used in these trialsvaried considerablywith respect to breed, age, stage of the cycle, and hormone levels and probablyrepresent the ran e of variabilitiesthat would occur with the extensive use of prostagfandin F20 for the synchronization of estrus, The results of the combinationsof PMSG, PGF2,-TXAMsalt with and without estrogenare recorded in Tables I, II, and III. From these results it is apparent that supplementaryestrogenhad no significant effect on the average time of onset of estrus in the donor animals. The average time of the onset of estrus in the two groups of donors not receivingestrogenwas 44 and 51 hours followingprostaglandin. In the three groups of donors receivingestrogen the average time to onset of estrus was 50, 36 and 48 hours followingprostaglandin. In contrast,recipients(groupsIII, IV and V) treatedwith estrogen between 32 and 35 hours followingprostaglandincame into estrus earlier (54, 48, and 52 hours) than animals (groupV) not receivingestrogen (78 hours) when the prostaglandintreatmentoccurredIn the middle luteal phase of the cycle. Delay of estrogenuntil 45 hours after prostaglandindid not shorten the interval to estrus significantly(group IV, 2x-1st). This group of animalswas just reachingpubertywhen treatedand their responsemay not be representativeof older cycling animals. Recipientanimals receivingprostaglandintoward the end of the luteal phase of the cycle had a shorter intervalto the onset of estrus, 41 hours, than those treated during the middle luteal phase, 78 hours. The high incidenceof recipientsshowing estrus shortlyafter prostaglandintreatmentwithout exogenousestrogen (Table II) is due primarilyto animals treated In group I, These animalswere used in the early stages of the transferexperimentsand severalof them were treatedvery late in the cycle. Similarly,the animals in group IV when treated the second time 19 days after expected time of estrus followingthe first treatmentshowed a very short intervalfrom treatment to estrus and were probably in proestruswhen treated. When using small groups of animals for embryo transfertwo synchronizations of are used the estrus may be advantageous. If two synchronizations second should probablybe started before the nineteenthday of the cycle because some of the animalswill have already started the proestrous phase of their cycle. Animals coming into estrus within 24 hours after prostaglandinare probablynot showing estrus in response to the treatment.

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THERIOGENOLOGY Exogenousestrogen,when given at mid-cycle,shortenedthe interval to estrus (TableIII) and resultedin better synchroniration between the donor and recipientanimals. It also tended to reduce the variationin the time of onset of estrus in the recipientanimals. Some of the recipients(4 of 27) receivingestrogenhad not ovulatedat the time of surgery 5 days after estrus. Failure of ovulationin heifers synchronizedwith a prostaglandinanaloguehas been reported (9) and our data are not sufficientto determineif failureof ovulation results from the exogenousestrogenor from some other cause. Short -et al. (10) induced estrus and LH release In spayed cows with estrogen. Estrus occurred20 to 24 hours followingInjection. Nancarrow and Radford (7) reported that estradiolbensoate given 28 hours after a PGF2c analogueadvanced the onset of estrus to 53 hours as compared to 75 hours in controlanimals. In Nancarrow'sexperimentthe onset of estrus averaged25 hours followingestradiol. In the above experiments the intervalfrom estradiolto estrus ranged from 20 to 28 hours and was similar to the time found in animals of group V in the experiments reportedhere. Rowson -et al. (1) have shown that close synchronization of estrus and ovulationbetween donor and recipientanimals is desirablefor embryo transferexperimentsand the data reportedhere indicatethat estrogencombinedwith PGF2o improvesthe synchronization when animals are treatedduring the mid luteal phase of the cycle. During the late luteal phase of the cycle estrogendoes not appear to have a beneficial effect. REFERENCES 1. Rowson, L. E. A., Lawson, R. A. S., Moor, R. M. and Baker. A. A. requirements. (1972) Egg transferin the cow: synchronization J. Reprod. Fert. 28, 427. 2. Newcomb, R. and Rowson, L. E. A. (1975) Conception rate after uterine transferof cow eggs, in relationto synchronization of oestrus and age of eggs. J. Reprod. Fert. 43, 539. 3. Rowson, L. E. A., Tervit, R. and Brand, A. (1972) The use of prostaglandinsfor the synchronization of oestrus in cattle. J. Reprod. Fert, 29, 145. 4. Lauderdale,J. W., Se&n, B. E., Stellflug,J. N., Chenault,J. R ., Thatcher,W. W.. Vincent, C. K. and Loyaneano,A. F. (1974) Fertilityof cattle followingPGF2, injection. J. Anim. sci. 38, 964. 5. Stellflug,J. N., Louis, T. M., Seguin, B. E. and Hafs, Ii.D. (1973) Luteolysisafter 30 or 60 mg PGF2c (TRAM salt) in heifers. J. Anim. Sci. 37, 330. 6. Welch, J. A., Hackett,A. J., Cunningham,C. J., Helshman,J. O., Ford, S. P,, Nadaraja,R., Hansel, W. and Inskeep,E. K.

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(1975) Control of estrus in lactatingbeef cows with prostaglandin P2o and eatradiolbenzoate. J. Anim, Sci. 41, 1686. 7. Nancaprow,C, D. and.Radford,H. M. (1975) Use of oestradiol benzoate to improve synchronization of oestrus in cattle. J. Reprod. Pert. 43, 404. 8. Hill, J. R,, Jr., Dickey, J. F. and Henricks,D. M. (1973) Eatrus and ovulationin PGP2ofPMStreatedheifers. J. Anim. Sci. 37, 315. 9. Smith, J. P. (1976) Use of a syntheticprostaglandinanalogue for synchronization of oeetrus in heifers. New ZealandVet. J. 24, 71. 10. Short, R. E., Rowland,B. E., Randel, R. D., Christensen,D. S. and Bellows,R, A. (1973) InducedLH release in spayed cows+ J. Anim. Sci. 37, 551.

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115

W

16

16

16

R

32

R

2x-2nd

R

16

D

2x-2nd

D

4ad

R

lrlst

7

21

D

R

12

12

12

19

19

10

0

16

15

14

14

8-14

7-15

11-14

32

43

2a'

1

48-187

R - recipient animals.

1

32-120

1

5 15-114

0

20

48-204

8-80

6

24-96

12-103

3

35-40

32-55

40-55

6-48

24-55

3

0

2 e

Animals not ovulating

animals in these groups could not be used for the transfer experiments so that ovulation or failure

2.000 to 3.000 IU 48 hr before PGP

78 + 9.2

of ovulation was not checked either by palpation or by laparotomy.

e%ma

d Au&us18 treated twice.

'D - donor animals received PEG

5.7

52 + 5.0

512

48 2 4.4

70 + 6.5

42

6-12

48 + 5.2

54 + 3.0

35

6-11

38

36 + 1.6

32

45

50 + 1.0 47 + 2.0

32

12-19

3.7

44 + 2.7 412

Raugeb

AIlimcllS not showing estrus

.~TNCHRONIZATI~NOF E~TRUS

Hours to estrus

TRE

Avg + SE

0N

11-20

IO-20

10-21

Range

b Hours following PGF2u (30 to 33 mg - THAM salt) injection.

aEstradio1 - 176, 500 pg.

V

IV

III

9

11

D

15

R

II

15

DC

I

Avg

Day

Hours to estrogena

wrm AND wrmom EsmIoL

of cycle received PGP2o

EFFECTS OF PGF2a

Group

I.

No. of animals

TABLE

58

Estrogen

Total

178

3.9

5.0

18.8

1.7

2.7a

o-12

2.8

1.7

2.3

5.2

a.1

13-24

6.2

3.3

4.5

12.1

14.3

10.8

25-36

42.1

35.8

34.1

40.6

55.2

47.6

59.4

37-48

23.0

27.5

34.1

9.4

13.8

23.8

8.1

49-60

12.9

15.0

15.9

12.5

8.6

9.5

8.1

61-72

2.8

4.2

1.1

12.5

73-96

Interval between PGF2, and onset of estrus (hours)

TIME INTERVAL BETWBEN INJECTION OF PGF 2a AND ONSET OF ESTRUS

aPercent of animals in estrus.

All treatments

120

88

Estrogen

Total

32

No estrogen

Recipients

37

21

No estrogen

Donors

Group

No. of treatments

TABLE II.

6.2

7.5

8.0

6.3

3.4

4.8

2.7

' 96

k *

8

8 0

!z

2

% ercent

O-12 6.7a

13-24

6.7

-

25-36

20.0

80.0

66.7

37-40

20.0

6.7

49-60

20.0

20.0

61-72

26.7

-

73-96

Interval between PGF,_ and onset of estrus (hours)

ESTRUS IN RECIPIENT ANIMALS OF GROUP V

COMPARISON OF ESTRAUIOL VS. NO ESTRADIOL ON RIE STNCRRONIZATION OF

of animals in estrus.

No estrogen

Estrogen

Recipients

Donors

Group

TABLE III.

13.3

6.7

6.7

> 96