176 • Impacts of Applied Genetics — Micro-Organisms, Plants, and Animals 
Figure 34. — Change in the Potential Number of 
Progeny per Sire per Year From 1939 to 1979 
Year 
SOURCE: R. H. Foote, Department of Animal Science, Cornell University, 
Ithaca, N.Y., unpublished data. 
bees and fish can now be artificially insemi- 
nated. 
It pei'mits the widespread use of germplasm 
from genetically superior sires. It saxes the 
farmer the cost of maintaining his own sires and 
is valuable in disease control, especially wlien 
germplasm, rather than animals, is imported or 
exported. An important barrier to the \\ ider use 
of Al, especially in producing beef cattle, is the 
need foi’ application of reliable estrus detection 
and estrus synchronization technologies. 
An expanded role for Al in the future w ill de- 
pend on the availability of accurate information 
about the genetic value of sperm axailahle for 
insemination. A nationwide information system 
for evaluating germplasm presently exists for 
only one species, dairy cattle. 
ESTRUS SYNCHRONIZATION 
Estrus, or "heat,” is the pei’iod during which 
the female will allow the male to mate vx ith her. 
The synchronization of estrus in a herd, using 
various drug treatments, greatly enhances ,\l 
and other reproduction programs. 
Federal regulations that limit tin* ust' of pi-os- 
taglandins or progestog(‘ns to induc'c .synchi'o- 
nized estrus in horses and nonlactating cows 
are the major barrier to moix* w idc’spix'ad use ol 
existing technology. 
SUPEROVIH, ATION 
SuperoMilalion is the hormonal stimulation ol 
the female, resulting in the rel(*ase from the 
oxary ol a largcM’ numbei' of oxa than normal 
(See tabk' 31 .) (iomhiiK'd xxith \1 and emhrxo 
transfer of th(' f(M'tiliz('d oxa into surrogate 
mothers, supei’oxiilated oxa can result in the 
production of normal otispring xxith tlu* same 
rates of success as those* folloxxing normal ox il- 
lation. 
The gri'ati'st barrier to su|)erox ulation is that 
the d(?gi’(?e of suci'i'ss cannot he |)redicted for an 
indix idual animal. Otiu'r harriers include xx ideix 
x arving (|ualitx ol hormone batches for ox ula- 
tion tri'atment, Food and Drug \dministration 
(Fl).\) restrictions, and lack of d.ita from xx Inch 
to judgi* the* {'fleets of repeated su|)erox ul.ition 
In the future*, inei'{*ase*el unele*rstaneling eil 
basie' phxsieileigie'al me'e hanisms xx ill l.ie ilitale* e*l- 
feirts te) impreixe* the* te*e hnole)gx II h.is .ideli- 
tieinal e’eimnu're ial pe)te*nti;il lor she*e*p anil i .illli* 
hushanilrx', einel mui h i urri*nl e*llort is illre*e ti*el 
loxx ards ele*x e*loping anil ti'sling a i'ommi*ri i.il 
proi'i'diire*. 
i:\IHR\0 Ri.eox I RX 
The* abililv to {'olli'e t te*rlili/e*el oxa Irom the* 
ox idui’ts or ute*rus is a ne*i e*ssar\ ste*p lor 1*111- 
brvo transler or storage* anil lor main l■\pl-rl 
me*nts in ri*|)roilue tix e* hiologx I he* li*e hnolotix 
is e*s|)e*e'ially im|)ortanl for re*se*are h into proilui 
ing ide*nlie*al txx ins. pi'i forming i*mbrxo hiopsie*-, 
for se*\ {le*te*rminalion. anel olhe*r pro|i*e !• ( 0111 
hilling supe*rox ulation, artilie ial insi*minalioi! 
anel e'liibryo re*i i)x e*rx maki*s il po-.sible* to l eil 
l(*ct e'liibrx'os from a xiuinf; hi*ile*r helore ri*.ie h 
ing |)ube*rty. U he*n some* ilisorile*r h.is ilamai;i*{l 
the* ox ielui'ts or ute*rus. I'liihrxo re*i e>xi*rx Irom a 
X aluable* animal make's proi ri'ation po-. able 
Both surgii'al anel noiisurgiial me-lhoels .ire* 
e*urie*ntly in use*. Surgii al ri*e iixi*rx is ne*( c- ,ai 
for shee'p, goats, anel pig.s: sue h o|)i*r.itiom are* 
limited hy the* ele*xe*lo[)im*nt ol se ar tissue \oc 
