van der Westhuysen, J.M.

van Niekerk, C.H.

English

AJOL - African Journals Online

S. Afr. J. Anim. ̂ Sci /, 59 -62 ( 1971 )SYNCHRONISATION OF OESTRUS IN SHEEP EARLY IN THE BREEDING SEASON:THE VAGINAL ENVIRONN1ENT AND FERTILITYJ.l\I. van der Westhuvsen* and C.H. van NiekerkDepartment of Animal Physiologlt, University of Stellenbosch, StellenboschOPSOMMING: SINKRONISASIE VAN OESTRUS BY SKAPE VROEC lN DIE TEELSEISOEN: DIE VAGINALE OMCEWING ENVRUCBAARHEID'n Ondersoek na die effek van dihidrostreptomysien setpille saam met fluorogesioon-aetaat geiinpregrcerde intravaginale (F-GA)sponse op sinkronisasie van oestrus en ovulasie is vroeg in die teclseisoen op tweehonderd-en'agl Dormer ooie uitgevoer. Hierbenewens is dievadnale omgewint en flora ondersoek. Alhoewel die sinkronisasie van oestrus goed was, het slegs 7O% v.a dte ooic ocsrrus g€roon, waarvan42% nrc be\( l  gcraak l |cl  nrr.  Mragdehkr ooh het bur{r swakkcr Acrcagcer opdr. behandeling as volwasse ooie (Tabel 2) en slegs 50% het oestrusgeroon vs. 81fr vL volwasse ooie. Die vaginale pH van ooie met FGA sponsies behandel was normaal en die bakteriese kontaminasie van diect ikale slym was oorhee$end van 'n ni(.hcamolitiese, nie-patogene, coliform oorsprong. Alhoewel di€ gebruik van antibiotiese setpillenie die voorkoms van oestrus of die petsentasie ooie beset vcrhoog het nie, het die hoe! pers€ntasie tweelinge, as gevolg van hierdie behande-ling, tot gevolg gehad dat mee. lamme.s tebore is per ooi wat lam (1,41 vs 1,26; P<0,05) (Tabel l). Dit word vetmoed dat die antibiotikumvoordelig was vir sperm oorlcwing in die genitale lBng van die ooi. Toctsing vir bronstige ooie lwee maal per dag in plaas van een maal hel totgevoft gehad dat l3/o meet bronstige ooie gevind is, terwyt dekking twee maal gedur€nde oestnrs in plaas van een maal die persenlasie ooiebeset en bmp€rsentasie net 6/o en 20% respektiewetik verhoog het.SUMMARYTwo hundred and eighl Dormer ewes werc included in an investillation into the effect on cwe fertility oi dihydrostreptomycin antibioticp€ssaries used with fluorogestone acetate-impregnated intravagirul (FGA) sponges for the synchronisation of oestrus and ovulalion early in thebreedint season. In addition, the vaeiinal cnvironmeni and tlora were investigated. Although synchronisation was good, only ?0r; of theew€s exhibiled oeslrus and of thelf 42% failed to conceive. Maidcn ewes had a lower oestrous response 6O/a cf.8l%\, but conceivedas well as maturc ewes. Although the use of antibiolic pessa es did nol imprcve oestrous response or corception rate, as a result of a highertwinning rate following this treatrnent, more lambs were born pcr ewe lambing (1,41 cf. 1,26; P<0,05). It is \uggested thar the antibioticpessaries were benencial lo sperm survival in the genetal tmct of the ewe.During the first successful oestrus synchronisationtrial using fluorogestone acetate-impregnated (FGA) spon-ges (Synchro-mate: G.D. Searle & Co.), Robinson (1964)noticed the accumulation of mucus in the vagina due tothe physical presence of these sponges. This finding hasbeen generally confirmed and the mucus has been shownto be a good medium for bacterial growth (Robinson,1964: Moore & Robinson, 1967; Wishart, 1967, Barker,1968). Although ferti l i ty is low following other methodsof application of progestagen, changes in the vaginal envi-ronrnent as a result of the insertion of sponges may be afactor specific to this method of progestagen administration.This experiment was therefore designed to explore thisaspect and also the practicability of handling large num-bers of synchronised ewes.ProcedureTwo hundred and eight healthy Dormer Stud ewes,ranging from maidens to old multiparous ewes, wereavailable. At the beginning of the breeding season, the eweswere randomly allotted to two treatment groups, balancedwith respect o age. On October 2l (group l) and October30 (group II), FGA sponges were introduced intravaginallyinto all ewes, half of which (groups IA and llA0 alsocarried a dihydrostreptomycin pessary (Solcon, Maybaker)*  Present address.  Div is ion of  Animal Physiology, Pr ivate Bag 2,  I renecranial to the sponge. Immediately prior to the insertion ofthese sponges, bacterial swabs were taken from the vaginasof eight randomly selected ewes from each of groups [Aand IB. This was done by opening the vulva to avoidcontamination and introducing steri le swabs about sixinches into the vagina. The staggering of the two groupswas intended to preclude "overwork" of the rams follow-ing sponge withdrawal 15 days later (i.e. at 1400h onNovember 11 and 14 respect ively) .  Immediately af tersponge removal, and also two days later, bacterial swabswere again taken from the vaginas of the same 16 ewes. Thecultured both aerobically and anaerobically on blood agarand later identif ied according to l lreed, Murray & Smith(1957). The approxirnate vaginal pH of all ewes in groupsIIA and IIB was measured immediately after sponge with-drawal by dabbing the removed sponges on wide range pHpaper.From a large proportion of virgin ewes the spongeshad to be removed by means of forceps. Physical traumato the hymenal region during insertion may have resultedin cicatrix formation and partial occlusion of the vagina.Both insertion and removal of the sponges in these ewesmust have been painful and their use seems to be con-traindicated in the maiden ewe.Commencing the morning after the sponges had beens9Table IThe oestrous response ond lambing performance of ewes treated with fluorogestone acetate-impregrwted (FGA) sponges for I5 days early in the breeding season(Groups IA & IIA: Treoted with antibiotics. Groups IB & IIB:No antibiotic treatment )I -6 Days after sponge removalNo. or,*., lIl"T.*", | % orro.^,(a) Oestrous resrynseTreatmentgroupl6-24 Days after sponge removal Overall ResponseNo. ewesservedEwesservedFirst Servl 68824Return toserviceLambsborn4 l2 26 3l, 7o, ,or^,served28,99J3!)28,57Lambs/ewesTotal ewesServed89891 7 8served% o rTotalIAIBTreatmentgloup1 0 3104207l t*r,  ilambed3 946ewesLambingrotat lc.n. %lambed I& I IA& I IB697 8t4'l66,9975,0070,5 320224236_ry6686,4085,5885,99(b) Lambing dataI umus/IIl rotallewesEwes conceiving I - 6 days after sponge removal Ewes conceiving 16-24 days after sponge removal Overall dataEwesservedLambsbornEweslambedIA & IIAIB & IIB697 8t417 7 , 7 863,3371,211,461 , 1 61 , 3 289891 7 86968r37l 8 s*  P<0 .05C.R. = Conception rateFig. l. Oestrus response and conception of ewesafter fluorogestone acetate (FGA) treatment forI5 days earb) in the breeding seasonremoved, the ewes in group I were teased once daily withfive vasectomised rams. The rams of proven fertility wereused each morning to serve the ewes on heat. Due to someshort oestrous periods observed during the teasing andmating of group I, it was decided to tease the second grouptwice daily (0800h and 1600h). Ewes were mated as soonas they were found on heat and again each morning as longas they remained on heat. For the second post-treatmentcycle all ewes, pooled into a single group, were teasedand served once daily in order to mate those ewes whichhad not conceived at the first cycle. After mating and untiltwo weeks prior to lambing, the ewes were kept on a lupinand oats stubblefield after which they were transferred tolucerne lands until they had all lambed. The Chi-squaretest was used for statistical analyses of the data of thisexperiment.ResultsOf the 208 ewes, one lost its sponge during thetreatment period and was withdrawn. The oestrous responseand lambing performance are presented in Figure I andTable l. From these results it is apparent that the anti-biotic treatment had no significant effect on oestrous re-sponse or conception rate. The antibiotic treated ewes,however, had a significantly higher lambing rate than theewes with FGA sponges only (P <0,05). Although the con-ception rate of maiden ewes was a little higher thanmultiparous ewes (P <0,25) the latter group had a greaterltrlIEa71 , 4 1 *Il6--l--|  77 ,53I rs,+ot;;l 0  l l  1 2  l r  1 4  1 560Table 2A comparison berween the breeding performance of moiden and multiparous ewes treated with fluorogestoneacetate-impregnated (FGA ) sponges early in the breeding season.F'irst Cycle Overall responseNo. of Ewes % otewes served TotalC.R.f t  No.  ewes /o of  tota l  No.  ewes C.R. f 'served lambedEweslambedNo. of Lambs/lambs ewelambingMultiparous ewesMaiden ewesl 4 l661 1 43 35 6 , 1 463,6481,43*  *  6450,00**  2 l| '35 94,74**4 3  6 5 , 1 5 * *103 76,29 L52 1,46**34 79,07 36 1,06*  *t47207 70,5 3 57,82 t78  86 ,00 137 7 6,97 188 1 ,36* *  P  < 0 , 0 1C.R. = Conception rateoestrous response and lambing rate (P4,01) Table 2).Attention should be drawn to the fact that betweenone and four days after sponge withdrawal, conceptionrate tended to decrease (Table 3). However, no relation-strip could be found between body weight and the onset ofoestrus. The effects of teasing and mating frequencieson the number of ewes in oestrus and on conception andlambing rates, are presented in Table 4.Table 3The conception rate of ewes coming on heot fromday 1 to day 4 after FGA sponge withdrawalDays after sponge withdrawalTeasing twice instead of once daily in a sig-nificant increase in the number of ewes found in oestrus(P<0,05) while lambing rates, but not concsption rates,were improved by mating twice. Sponge removed fromewes not carrying antibiotic pessaries were accompaniedby 3-5 ml of a greyish, highly odiferous fluid, whilethose with antibiotic pessaries had a similar quantityof viscous somewhat cloudy, sweetsmelling mucus. The pHof the cervical mucus of antibiotic-treated ewes was higherthan the mucus of untreated ewes (P<0,01) (Table 5), buthad no effect on conception rate.Table 5The vogirwl pH of ewes treated with progestagen im-pregnated sponges with an antibiotic (Group A),or without an antibiotic (Group B)Number of ewes on heatNumber of ewes conceivingConception nrc ( fo)3 22268,880496 l , 325l 352,06233,3GroupsB0 ,19* *  6 ,90  10 ,23* *7 ,6  6 ,4  -7 ,6Mean vaginal pHRange7 , 1 56,4Table 4The oestrous response, conception rate and lambing rateof ewes teosed once or twice daily and mated once or twiceduring oestnts treatmentFrequencyOnce ( %) Twice ( %)( * *P  <  0 ,01)Although no bacterial counts were made, the typesof bacterial which were isolated from the cultures of thevaginal swabs showed only random variation between treat-ment groups and between the three sampling periods.The non-specific, non-pathogenic and non-haemolytic coli-from bacterial were found in all cultures, followed bycorynebacteriunt spp. ( mainly Corynebacterium pyogenes).The vaginas of these ewes never appeared infected andwere clinically normal two days after sponge removal.DiscussionThe use of FGA sponges early in the breedingseason provided somewhat disappointing results. Seventyper cent of the ewes exhibited oestrus at the first post-t . Oestous response - teased onceor twice dailyConception rate - mated onceor twice during oestrusLambing rate - mated once ortwice during oestrus2.3.65,6956,1274,4378,64*62,0092,00***  P <  0 , 0 5 * *  P < 0 , 0 16 1treatment cycle and of these 42% failed to conceive.The low oestrous response, especially amongst maidenewes (Table 2) probably resulted from the high incidenceof silent ovulations and short heat periods early in the breed-ing season (Radford & Watson, 1955; Glimp, 1967; Healey&Eastoe, 1967;Moore & Robinson, 1967; Shelton & Moore,1967). The previous lambing history of this stud also indi-cated that the maiden ewes had a shorter active breedingseason and invariably showed their first fertile oestrus laterin the breeding season. The decrease in fertility from dayI to day 4 after sponge removal (Table 3), and the lowoestrous response, suggest that a degree of endocrineimbalance had occurred between progesterone and oestro-gens, both of which are involved in the manifestation ofoestrous behaviour. The dosage of progestagen may havebeen inadequate considering the annual rhythmic changeof the sensitivity of the ewe to progesterone (Lamond,1964). Robinson (1967) states that a progesterone-oestro-gen regime adequate for the production of oestrous be-haviour in autumn, (the normal breeding season) is in-adequate in spring. This and the seasonal decline in gon-adotropin content and secretion of the anterior pituitary(Lamond, 1960) can possibly account for the low oestrousresponse and conception rate. During the second post-treatment cycle, however, conception rate was about 13frhigher (P<0,07).The fact that teasing twice daily increased the num-ber of  ewes found in oestrus by 13fr ,  suggests hat at  th isstage in the breeding season a significant number of eweshave short heat periods. Two services during oestrus gavea 2l/ '  higher lambing rate compared with ewes matedonce, due to a higher twinning rate.Both in this experiment and in that of Moore &Robinson (1967) the use of antibiotics had no effect onoestrous response, conception rate (Table l) or vaginalflora. On the other hand it increased lambing rateby l5/,,due to a higher twinning rate. This finding may be due toincreased fertilization of the second (twinning) ovulationas a result of a more favourable vaginal environment forincreased survival, longevity and fertilizing capacity of thespermatozoa. Bush, Ludwick, Ferguson & Ely (1950)showed a correlation between the bacterial cnunt(Co-rynebocterium p;togenes) of semen diluted for artificialinsemination and fertility in cattle, while the beneficialeffects on ferti l i ty of the inclusion of antibiotics in suchsemen has been shown by various workers (Foote & Brat-ton,  1950; Almquist ,  l95l ;  Steward, Melrose & Wilson,195 I ). Thus, although Moore, Quinlivan, Robinson & Smith(1967) found that the accumulated mucus present aftersponge removal had no effect on the motility of thespermatozoa, the possible effect of bacterial contarnina-tion ofi the fertility and sperm survival cannot be totallyexcluded. It is of interest that the presence of antibioticpessaries changed the pH of the vagina and cervical mucus,but this had no effect on conception rate as the range fellwithin the normal buffering power of the seminal plas-ma (Asdell, 1946). The vaginal pH (6,9) of ewes treatedwith FGA sponges only, was normal (Asdell, 1946).It is concluded that the major cause for loweredfertility after the use of FGA sponges must be the resultof some endocrine disturbance, possibly affecting sementransport (Quinlivan & Robinson, 1967), the oestrous-owlation relationship of fertilization. Nevertheless, somebenefit can be derived from the use of antibiotic pessarieswith FGA sponges. They appear to increase fecundity,perhaps through improved sperm survival and/or fertiliz-ation rate resulting from a more favourable vaginal en-vironment.AcknowledgementsWe would l ike to thank Mr. WJ.J. van Rensburgfor the bacterial investigation and Mr. H.E. Theron fortechnical assistance, Drs. G.L. Hunter and P.C. Belonjefor readhg the manuscript and offering constructivesuggestions in the preparation of this paper.ReferencesALMQUIST, J .O..  195 I  .  J.  Dairy Sci .  819.ASDELL,S.A., I 946. Patterns of Mammalian Reproduction.New York: Comstock.BARKER, C.A.V.,  1968. Proc.  VIth int .  Congr.  Anim.Reprod.,  Par is,  2,  1393.BREED, R.S.,  MURRAY, E.D.G. & SMITH, N.R.,  I97IBergey's Manual of Determinative Bacteriology. Balti-more: Will iams & Wilkins.BUSH, LJ. ,  LUDWICK, T.M.,  FERGUSON, L.C. & ELY,F. ,  1950.  J .  Da i ry  Sc i .  33 ,  633.FOOTE, R.H. & BRATTON, R.W.,  1950. J.  Dairy Sci .33,  544.GLIMP, H.A.,  1967. J.  Anim. Sci .  26,  944.HEALEY, J.S. & EASTOE, R.D., 1967. Agric. Gaz. N.S.W.7 9 , 6 6 .LAMOND,  D.R. ,  1960.  Nature ,  Lond.  186,971.LAMOND,  D.R. ,  1964.  J .  Reprod.  Fer t .  8 ,  l0 l -114.MOORE, N.W.,  QUINLIVAN, T.D.,  ROBINSON, T.J.& SMITH, J.F. ,  1967. Ch. XII  in Control  of  theovarian cycle in the sheep, ed. TJ. Robinson.Sydney University Press.MOORE, N.W. & ROBINSON, T.J. ,  1967. Ch. 7 in con-trol of the ovarian cycle in sheep, ed. T.J. Robinson.Sydney University Press.QUINLIVAN, T.D. & ROBINSON, T.J. ,  1967. Ch. g inControl of the ovarian cycle in sheep, ed. T.J. Robin-son. Sydney University Press.RADFORD, H.M.,  & WATSON, R.H.,  1965. Aust.  J.agr ic.  Res. 6,  431.ROBINSON, T.J., 1964. ln: Recent advances in ovarian& synthetic steroids and control of ovarian function -Proceedings of Symposium in Sydney Universityp p .  t 2 - 2 4 .SHELTON, J.N. & MOORE, N.W., 1967 . Ch. 5 in Controlof the ovarian cycle in the sheep, ed. T.J. Robinson.Sydney University Press.STEWARD, D.L. ,  MELROSE, D.R. & WLSON, W.R.,  I95 I .Vet.  Rec. 63, 609.WISHART, D.F.,  1967. Vet.  Rec. 80,276.62

Synchronisation of oestrus in sheep early in the breeding season: the vaginal environment and fertility

Wentzel, D

S. Afr. J. Anim. Sci. I, 101 - 102 ( I97l )PROGRESS THROUGH SELECTION AGAINST THE ABORTING ANGORA GOATJ.M. van der Westhuysen* and D. WentzelAgricultural Research Institute oJ'the Karoo Region. Midrletburg, c.p.Several investigations into the problem of habitualabortion in Angora goats have been undertaken (van Heer-den, 1963, van Rensburg, 1965, 1970). Although thesecontributed to the knowledge of physiological aspectsof abortion, the origin and the genetic basis remain ob-scure. Van Heerden ( 1964), however, made certain longterm managerial recommendations to reduce the incidenceof abortion with which a certain degree of success has beenachieved. The object of the present stucly was to assessthe value of elimination of aborter Angora goat does on thefarm using breeding records.The data were obtained from the records of studbreeders over a period of nine years. The number of timeskidded, number of kids born alive or sti l l-born and abor-tions of 105 aborters and 108 "notrmal" does and theirprogeny were compared. Normal does were those whichhad never aborted, while aborters were those which haclaborted at least once before culling. The latter were identi-fied by visual inspection of the does for exterior signs ofabortion twice weekly. All the goats were kept under ex-tensive semi-arid range conditions. The reproductive per-formance of normal and aborter does and their progeny issummarised in Table 1.No significant differences occured in the number ofdoes which kidded following observed mating or the numberof kids born per doe when abortion were taken as kidsborn. Nor were significant differences in fertility and fe-cundity found between the F I progeny of normal andaborter does. Moreover, 33f of the F1 progeny of abor-ters aborted cf. 35% of the progeny of normal does. Itis therefore concluded that under these managerial con-ditions very little genetic progress can be made by eli-minating aborters.The hypothcsis that the abortion phenomenon washeritable was t ' irst proposed by van Heerden (1963,1964). Van Rensburg (1965) subsequently confirmed thishypothesis when he lound, on small numbersof goats, thatmohair production characters (with a fairly high inheritance)were l inked with abortion. Van Heerden (1964) successfullyreduced the abortion rate of a flock, where no system ofselection against aborters was practised, by eliminatingTable IReproduction dota of normally reproducing and aborting Angora goatdoes and their progenyNormal Dams Abor l ine DamsDanr Progcny l)arn ProgenyNumber of doesTotal times matedTotal times pregnant*Total  number of  k ids born**Does aborting** *Kids st i l lborn****N1086 2 76041 5 60096.41 1 5 . 2(.)0N2038547821 7 9i l89 1 . 6l : l  l- i : r . { ' :1 , 094,0i  1 8 . 8l i_)0 .03 , 8Nr 5 4638558s 6 l5 lI4/087 ,0IT2,'T3 3 , 11 , 5*Pregnant: Does kidded f does aborted**Percentage of  lambs born rvas calculated wrthout  br ineing abort ions into calru i l t i<rrr  { ; -y.  , r r r i r  i : , r r rbs l iorn pcr  cwc larnbing).***Percentage aborters:  l :wes abort ing per cwc prcgl lant .**+St i l lb i r ths as a percentage of  tota l  lambs born.*Present address: Division of Anirnal Physiology, PrivateBag 2 , l rene.l 0 lTable 2Reproduction data of an Angora goat stud from 1961 to 1969 where aborters were called196919671966 1967196519641963t9621961Yearl. Does mated2. Does non-pregnant3" Does aborted4. Live Kids5. Multiple Kids6. Kids stillborno//0o//0f'0//oo//03128 , 17 , 183,910.42 , 134512 ,L13,g73,29,31 , 636'.l15 ,34,277 ,412,34,43284,28.884,416,23,53577 ,31 8 , I75,120,10,73 6 16,41 3 , 979,39,42,035710,77 ,580,1l0 , ll r7293 3163 ,8  l 0 , l8,8 2,583,0 Es, l4,4 22,83,2 2,8habitual aborting does. This limited the occurrence tofirst time aborters only. The present results showed that,after using this method for nine years. the abortion rate ofa stud still varied round a mean of 9,4/' (Table 2).ln conclusion it appears that genetic progress canonly be made up to a minimum value, which is greatly in-fluenced by the environmental conditions, feeding level(van der Westhuysen & Roelofse, l97l) and by the presentsystem of identification and elimination of aborter andpotential aborter does. This is probably due to the in-ability to identify the endocrinological abnormality priorto abortions so that total elimination of aborters is impos-sible as abortion rarely occurs after the first conception.In addition, selection of does for mohair quality and pro-duction may favour potential aborters (van Rensburg,1965, l97O). Furthermore, intensive selection and use oframs with superior mohair, may also contribute to theproblem. Despite the lack of progress in eliminating theproblem, we support the approach of van Heerden (1964)that abortion should be constantly eliminated in order tomaintain a low incidence of abortion. More attentioncould, however, be given in future to the contribution ofthe ram.AcknowledgementThe author are indebted to the Angora goat studbreeders for permission to study and use the records.ReferencesVAN DER WESTHUYSEN, J.M. & ROELOFSE, C.S.M.B.,1971. Agroanimalia (in the press).VAN HEERDEN, K.M., 1963. Onderstepoort J. vet. Res.30 ,23 .VAN HEERDEN, K.M., 1964. Jl S. Afr. vet. med. Ass.35 ,  19 .VAN RENSBURG, SJ., 1965. Jl S. Afr. vet. med. Ass.3 6 , 4 9 1 .VAN RENSBURG,S.J., 1970. Reproductive physiology andendocrinology of normal and habitually abortingAngora goats. D.V.Sc. thesis, University of Pretoria.t02

Progress through selection against the aborting Angora goat

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Synchronisation of oestrus in sheep early in the breeding season: the vaginal environment and fertility

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