DMancastir Fanning Saturday, January 28,1989
Improving
Reproductive
Efficiency
Producers have lots of ways to
measure reproductive efficiency --
pigs/litter, litters/year, pigs/sow/
year, pigs/crate/year, total herd
feed conversion and profit, to
mention a few. All pf these are
useful. But none of them tells the
whole story. Whatever numbers
you chose to monitor herd perfor
mance, remember that there are
two major overhead expenses you
must cover; 1) the breeding herd
and 2) the facilities.
The breeding herd may be effi
cient, but you may be short in the
total number of sows you’re
breeding. That means the facility
cost will be high for each pig sold.
This is a significant problem for
almost every producer I visit that
has a “reproductive problem" in
his herd.
Another problem that occai
sionally happens is that you may
be able to keep the facilities at
capacity, but you’re breeding herd
might be abnormally large and
inefficient.
The point is it’s important to be
sure that the farrowing house is
full and the breeding herd is effi
cient Here are a few tips on get
ting that done.
CULLING
The goal behind any culling
system is to improve genetic merit
in the herd. Unfortunately, it sel
dom happens that way. First,
reproductive traits are influenced
more by management than gene
tics. Second the boars maintain
most of the genetic material in the
herd, especially when you’re sav
ing your own replacement gilts.
And finally, most sows are culled
for reasons other than
productivity.
Be cautious not to over-cull,
since you will farrow a greater
percentage of gilts. The peak per
formance of a sow occurs in the
3rd through 6th parity, so it’s
important to maintain the bulk of
your sow herd in this age bracket
if at all practical.
GILT POOL
MANAGEMENT
Three secrets to a well
managed gilt pool; 1) know when
you’ll need the gilts 2) Have
enough gilts available 3) breed or
sell all gilts (of breeding age) in
the pool within 30 days. The steps
you can follow to meets these
goals;
1. For every sow you expect to
cull, move 3 to 4 gilts from the fin
ishing floor to the breeding bam.
2. Be sure gilts have fence line
contact with the boar. 3. Sell any
gilts that don’t cycle within the
first 7 to 10 days. 4. Keep the gilts
that cycle and breed them 3 weeks
later (on their second cycle).
This system automatically
selects for early estrus. It allows
you to sell the non-cycling gilts at
a typical market weight. And it
permits breeding on the second
heat.
Pork
Prose
by
Kenneth B. Kephart
Penn State Extension Swine Specialist
Many systems, instead, main
tain one or two gilts for every
“empty crate.” Gilts are bred on
their second service or whenever
an empty spot needs filled. The
non-cycling gilts go to market at
280 to 300 pounds. The result is
gilts are not selected for early
estrus. Feed expenses are often
higher. And the non-cycling gilts
'are discounted at the market
because they’re heavy.
OVER-FARROWING
An example of over-farrowing
is farrowing 14 to 15 sows for a
farrowing room that contains 12
crates. The “extra" sows are
weaned at day 2 or 3, pigs are fos
tered to other sows, and litters are
standardized at about 12 per sow.
The space, labor and feed for the
extra sows will cost about
$BO/sow. That’s equivalent to $8
to $lO for every additional live
pig, and for most producers, that’s
a good investment. But to get it
done, the gilt pool has to be man
aged closely.
HEAT
DETECTION
Keep groups small (less than
10). Rely on die boar and yourself
for spotting sows in heat. Watch
timid sows closely. Check heat
twice per day.
OPTIMAL TIME
FOR BREEDING
The ideal time to breed the
average sow is about 28 hours
after the beginning of estrus. Sows
should be bred roughly 12 hours
after they first come into heat and
again about 12 hours later.
Because gilts exhibit heat for a
much shorter time than sows, they
should be bred every 12 hours
from the time you first see them in
heat.
NUMBER OF
SERVICES
For the sow: two services pro
vides a big boost in conception
rate and litter size compared to
one service. Three services may
yield a slight benefit in conception
rate over two services. More than
three services is not a good invest
ment Sows should be bred to two
different boars, in the event that
one boar is sub-fertile.
For the boar: Anytime you use a
boar more once a day or more than
six times per week, you risk a drop
in conception rate and litter size.
As a rule of thumb, wften weaning
a group of sows, provide one boar
for every two to three sows.
HANDMATING VS
PENMATING
The two drawbacks to handmat
ing are, of course, time and space.
I don’t think I’ve every met a pro
ducer that questioned die merits of
handmating. The problem for
many of you is finding the time.
But if you can take the time, you
can potentially overcome the typi
cal problems observed with pen
mating - boar overuse, sows
missed, and poor matings. If hand
mating is just not possible fix' your
operation, then provide the next
best thing by rotating boars at least
Pork Industry Forum Planned
DES MOINES, IA More
than 500 pork producer leaders
and elected producer delegates
from across the country will join
together at Kansas City’s Hyatt
Regency Crown Center Hotel for
the 1989 National Pork Industry
Frum, March 1-3.
During Pork Forum ‘B9, the
National Pork Producers Council,
National Pork Council Women,
Pork Act Delegate Body and the
National Pork Board will hold
their annual meetings and take
action on many important issues.
These sessions provide ongoing
grassroots producer input into
domestic and international con
cerns of importance to the pork
industry.
The central theme, “Commit
ment to Quality,” will carry
through all aspects of the event
emphasizing the industry’s priori
ties in planning for the 21st
Century.
Len Dawson, former Kansas
once per day.
EFFECTS OF
HIGH
TEMPERATURE
Sows exposed to high tempera
tures (90 degrees F) during the
first two weeks of pregnancy will
often show reduced conception
rates or decreased litter size.
Boars with only a 1 degree ele
vation in body temperature, can
have a 70% reduction in sperm
output. Recovery time is 6 to 8
weeks.
If you haven’t figured it out
already, these are awfully good
reasons to put drip coolers in the
breeding bam.
One observation that’s some
times confused with high tempera
tures is seasonal infertility. Sea
sonal infertility seems to be asso
ciated more with decreasing
day-length than with high temper
ature. Research shows that breed
ing late summer to early fall may
cause an irregular return to estrus,
with little or no change in litter
size.
PREGANCY
DETECTION
The two classical methods of
detecting pregnancy are return to
heat and ultrasound. By observing
for return to heat, you’ll find the
sows early (day 21). It’s accurate
(up to 100%). And you can re
breed right away, or cull the sow if
desired. But it’s somewhat labor
intensive.
Ultrasound, requires less time
and is nearly as accurate as check
ing for heat return. Unfortunately,
you can’t use the method until day
30, and sows can’rbe re-bred until
their second estrus at day 42.
Compared to checking for heat
retrun, this will cost you close to
$lO, for every non-pregnant sow
you find.
For the producer that doesn’t
use either of these methods, he can
only hope that most sows settle the
first time. If he doesn’t find them
until the day they come into the
farrowing house, he knows he’s
shot at least $5O.
SUMMARY 1. Have an effi
cient gilt pool. Do whatever it
takes on your operation to keep
those farrowing crates full. Con
sider “over-breeding” so you can
"over-farrow.”
2. For group weaning situa
tions, remember the “Two-to-
Three“ rule of thumb: Two to
three services per sow, and two to
three sows for every boar.
3. Check pregnancy as soon as
practical. Checking for return to
heat takes more time than ultra
sound, but it pays dividends in
feed saved.
City Chiefs football quarterback
and well-known sports broadcas
ter, will be the featured Forum
luncheon speaker on Friday,
March 3. A special program to
honor Pork Industry Hall of Fame
recipients, Paul McNutt, lowa
City, lowa, and George Brauer,
Oaicford, 111., along with Distin
guished Service Award winners.
Annual Keystone Pork
Congress Scheduled
HARRISBURG The
eleventh annual Keystone Pork
Congress will be held February
15, 1988 at the Penn Harris Inn in
Camp Hill. This year’s KPC will
feature a trade show with more
than 40 exhibits, a “Pork Bowl”
contest for 4-H and FFA mem
bers, educational seminars and the
annual banquet of the Pennsylva
nia Pork Producers Council. Dr,
Chicken Stud Farms
On The
UNIVERSITY PARK (Centre)
Stud farms are just for champ
ion race horses and prize bulls,
right? Not anymore. Think
chickens.
According to Penn State scien
tists Dr. Roy Hammerstedt, pro
fessor of biochemistry, and Dr.
Guy Barbato, assistant professor
of poultry science, commercial
chicken stud farms are definitely
on the horizon. The two research
ers have even started a prototype
on Penn State’s University Park
campus as part of their research on
the effects of freezing on the pre
servation of rooster semen.
The 600 birds in Hammerstedt
and Barbato’s chicken stud farm
came from strains developed at
the University of British Colum
bia and the University of Minne
sota where researchers bred them
according to how well the rooster
semen froze.
With the aid of a grant from the
U.S. Department of Agriculture,
the two Penn State scientists are
now comparing the biochemical
and genetic traits of the lines that
freeze well with the lines that
don’t
“I don’t think we’ll find any
thing like a ‘freeze gene,”’ Ham
merstedt says. “But 1 do think
there may be compensatory
enzymes in certain chicken lines,
for example, that enable their
sperm cells to better withstand the
stress of freezing and thawing and
still remain fertile.”
Hammerstedt, who has studied
the basic biochemistry of semen
from a variety of animals during
the last 20 years, is looking for
biochemical traits that enhance
freezability as well as the best
freezing methods.
Barbato, a poultry specialist, is
studying the ways in which the
desirable traits are inherited.
Although scientists have deve
loped successful techniques for
freezing horse and cattle semen,
no one has developed commercial
techniques for chickens.
Barbato notes, “If you talk to
some people in the field, they say
it is impossible to freeze chicken
sperm.”
The ability to freeze rooster
semen would enable breeders to
increase efficiency and maximize
genetic progress. Barbato explains
that a prize rooster might be able
to keep 10 to 12 females fertile.
“That rooster really only makes
a small genetic contribution to the
Marvin Gamer, SL Joseph, Mo.
and Keith Myers, Grundy Center,
lowa, will take place during the
National Forum Banquet on Fri
day evening.
Pork producers not directly
involved as voting delegates are
welcome to attend any of the dele
gate meetings to watch key indus
try decisions being made.
Roy Shultz, practicing veterina
rian from Avoca, lowa is the fea
tured speaker on the educational
program and will discuss “Herd
Health Programs”. Invited ban
quet speaker is Ed Johnson, presi
dent of the Agri-Broadcasting
Network in Columbus, OH. For a
program copy, contact your coun
ty extension office. To make ban
quet reservations, call Stephen
Burkholder 215/682-2871.
Horizon
next generation,” he notes. “By
being able to freeze his semen,
you are able to go to 100 or 200
hens. You can mail the semen to
California or to Australia or Bra
zil, or to Third World countries
that are having trouble improving
their genetic stock.
“Freezing semen maximizes
genetic progress and if we are able
to maximize progress, we can
directly influence the cost to the
consumer.”
Barbato and Hammerstedt
agree that when a reliable and eco
nomic method of freezing rooster
semen is found, chicken stud
farms, similar to theirs, will be the
natural result. These stud farms
will, however, differ significantly
from horse and cattle farms.
Barbato says, “Frozen semen is
actually used to produce cows that
are used for milk production. That
is just completely unrealistic for
chickens since the U.S. produces
more than 5.5 billion chickens a
year.”
He sees artificial insemination
with frozeii genetically superior
semen obtained front chicken stud
farms as a tool for breeders who
then will supply chicken produc
ers with superior stock.
Hammerstedt points out that the
Penn State research will have
other applications beyond chicken
stud farms as well. Since sperm
are single cells, the researchers
will be able to use them as a model
for other cells or even whole
organs. He notes, “There probably
is a common set of physical prop
erties that allow a cell to freeze.”
Learning those properties will
be useful to those who want, for
example, to preserve human
organs for transplant by freezing.
1989 Farm Show
Turkey Winners
Turkey
Large Young Turkoy Tome
1. Bolton Turkey Perm: 2. Bolton Turkey
Farm, 3. Bolton Turkey Farm.
Large Young Turkey Hene
1. Konhaus Farms: 2. Strockland Farms;
3 Bolton Turkey Farm.
Medium Young Turkey Hene
1. Konhaus Farms; 2 Konhaus Farms; 3
Konhaus Farms.
Dressed Capone
1. Susan Glouner; 2. E. Ruth Peifer, 3-
Mervm Reiter.
Dressed Capons
FFA Members a Schools
1 Kevin Sangrey; 2. Keith Eshelman,
Champion Dressed Turkey
Bolton Turkey Farm
Best Dressed Turkey Display
Bolton Turkey Farm
Best Dressed Capon
Butsn Glouner
Best Dressed Capon • Jr. Class
Kevin Sangrey