en el área de las biociencias: crisis del sistema postdoctoral

71 .

neede d to corrob o rate the evidence that sp erm transp o rt i s enhanc e d

by reffioving the re tardation imp o s ed by the c e rvix . I n the se exp eriment s there was no difference betv1e en one ins er.c.ination bef o re

o r

after

o vulation, or betvre en a sinele o r d o uble dose o f sp er:r,ato z o a . 'I'hi s c ould have b e e n a re sult of the large numbers o f

sp erm

dep o s ited o r that dep os ition a t the uterus re.r.':oved the eff e c t o f the c ervix where e ndo crinological effe c t s have their r:1a j o r iT'.:flue!'lc e . Further 7ro rk using variavle nw::tbers of sp erm p e r ins er::ination r�ight indi cate

the limits to w: i c h fre shly ex t er.de d ram semen c ould b e used. I t is de s i rabl e tha-t future s tu ii e s o f spere transp o rt be s uppl emente:l 71i th lamb ing resul ": s a s the in utero viab il i ty of ova fertil i z ed by fro z e n sp ermatozoa ha s no t b een investigated.

The development of a suc c e s :.ful r::e thod of synchroniz ing

ovulation and ins e::cinatinc vri thout ob servation for o e s trus , ;!:icht 77i·:':.en the s c op e of artific ial b re eding of she ep in :�e-,7 Zealand , even.

-.i i

thout the use of frozer. semen. J iluted s emen uso:l on the lay of , or day

after collection

ha s

b ee n very suc c e s sfully achieved in the dairy cattle indus try and such a tecl".nological devel opment '.'ii th ram s eJr;en, rr,ay

have application in F ew Zec.land .

Although the inj e ction of ECG rr�y not b e entirely s ati sfactory for the induction o f ovulations, the use of S)�thetic gonadotrophin­ rele as ing fac tors night be more promi

s

ing. P.ovrever, as the cervix o f

the ewe app ears t o b e the· s ite o f sper� transp o rt failure afte r o e s trus synchronization, the inseminating ins trument used in thi s s tudy might allow successful s et-time inseminations after p roge s tagen treatment , without the nee d for exp ensive ovulating ho�one s .

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In document Tecnología & Sociedad, Nº 6, 2017 (número completo) (página 69-75)