Tanksley, T. D. Jr.

Texas A&M University

'EX 
TEXAS A&M 
AGRICULTURAL 
.. HUTCHISON. DIRECT OF^ 
;$d 
* >-. UNIVERSITY 
EXTENSION SERV 
I. COLLEGE STATION. TEXAS 
*Wn-the-FarmN Pmmmce  
Full imfomtation qn this pr;ogrgm can bs &wined from your laool w n t y  
t o l d  agsnt or Extandon Swine Speclalist at TOXQI A M I  University. 
FOR THE COMMERCIAL PRODUCER 
1. Choose and follow a breeding plan. Hybrid vigor is of much importance in 
commercial hog production. Rotation of purebred boars of three breeds is an effective 
practice for utilizing the principle of hybrid vigor. Choose breeds that provide the 
best combination of traits in their crosses. 
2. Select and use purebred boars from production-tested stock. Insist on rate 
of gain, feed efficiency and carcass information when buying boars. Purebred breeders 
participating in one of the testing programs outlined will have boars with this infor- 
mation. 
3. Select the most efficient, meatiest gilts for replacements. The "ON-THE-FARM" 
selection program based on litter records, rate of gain and meatiness as determined 
by "backfat probing" is outlined in this publication to help select the best gilts. 
Selecting Meatier Hogs 
T. D. Tanksley, Jr. 
Associate Professor and Extension Swine Specialist 
Texas A@M University 
T EXAS SWINE PRODUCERS can produce more muscular hogs with less fat by following 
a planned selection and breeding program. Such 
hogs are more valuable on today's market and their 
lean, tender cuts find favor with American house- 
wi\.cs. 
This meatier hog can be produced by selecting 
gilts and boars that have adequate length (30-inch 
carcass on a 200-pound hog) with thick, muscular 
conformation, with just enough fat at market 
weight to insure carcass firmness and give quality 
and flavor to the cuts. This meatier hog must come 
from sows that farrow and raise large litters of big 
pigs; he must be fast growing, be able to convert 
qrain and supplement into pounds of pork at an 
efficient rate and possess other traits that mean 
profit for the producer. 
Any profitable selection program must be based 
on the ability of an animal to perform. This opin- 
ion is reflected in the wider acceptance and use of 
Production Registry, breed Meat-Type Certifica- 
tion Programs, "On-the-Farm" Performance Test- 
ing and Gilt Selection Programs. 
, 
No single selection plan fits all breeders and pro- 
ducers, but sound production information coupled 
with competent visual appraisal permits the most 
accurate selection of breeding animals. 
The commercial producer, by selecting produc- 
tion-tested boars and mating them to "On-the- 
Farm" selected gilts, as outlined in this publication, 
will produce meat-type hogs most efficiently. The 
.* 
commercial producer should buy boars from breed- 
ers that have satisfactory litter records, rate-of-gain, 
feed efficiency and carcass cut-out information on 
them. Extra time, effort and money spent in select- 
ing boars generally give the greatest return of any 
investment you make in the hog business. Attempt 
to buy boars from breeders participating in one of 
the testing programs described inside the front 
cover. Always try to evaluate as many of the litter- 
mates and close kin of your boar as possible to help 
get a more dependable estimate of his potential. 
Selecting Gilts 
The success of the purebred breeder and com- 
mercial producer is greatly influenced by their abil- 
ity to select and retain the most productive gilts in 
their breeding herd. The following "On-the-FarmJ' 
selection program is one of the most highly effec- 
tive programs for selecting more muscular, more 
profitable gilts. This program supplements pure- 
bred selection programs and serves as a guide for 
commercial and purebred swine producers. 
The program @ based on the basic fundamentals 
that are of greatest economic importance to swine 
producers : 
1. Sow productivity 
Large litters of thrifty pigs raked to weaning are Cross sections of the loin at tenth rib of a meat-type hog (left) and a fat-type (right). The meat-type not only has the first essential to a profitable pork program. less fat, but more red meat (muscle). 
Replacement animals should be selected only within the breeds that are really "meaty" anti 
from the largest, heaviest litters. use them in his breeding program. 
2. Rapid,  ef icient growth 
Rapidly growing hogs which reach 200 pounds 
at 5 to 6 months of age are normally cheaper to 
produce than slower growing hop.  Therefore, 
some measure of the pig's .ability to gain should 
be included in the selection program. 
3. 'cMeatiness" 
Amount of muscling is the most important cri- 
terion in determining whether a hog is truly 
meat-type. Only market ho,q with good muscling 
and with a high lean-to-fat ratio are truly meat- 
type. Meat-type hogs can be found in all breeds 
of ?wine. The breeder muyt find those strains 
Muscling or "meatiness" is difficult to evaluate 
on the live hog by visual inspection alone. The 
backfat probe enables the producer to make more 
accurate selections for meatiness. The iverage bach- 
fat thickness, as determined by the live-prohr 
method, is the best measurement that is presenth 
available for estimating the amount of musclinc 
and meatiness in the live animal. After the average 
backfat thickness has been measured accurately on 
the live hog, a producer can appraise meatiness in 
measured animals by comparing their relative bod1 
thickness and amount of backfat thickness. 
The general plan for carrying out this "On-the- 
FarmJ' selection program follows : 
Plan A-For the Commercial Producer 
1. Ear-notch the gilt pigs in big litters at birth. (Give each 
litter a different ear notch. Record ear notch and farrowing 
date of each litter. See page 8 for simple ear-notching sys- 
tem. To get as much information on each sow as possible, 
it is advisable to ear-notch all pigs in all litters at birth and 
weigh all pigs at 35 or 56 days.) 
2. Place the gilts on full feed at weaning time. Leave them 
on a high energy ration until they weigh 180-220 pounds. 
This practice permits the gilts to display their inherent tend- 
ency to be meaty or overfat. (Some producers may desire to 
separate the better looking gilts from the rest of the herd at 
125-150 pounds and feed them a more bulky ration. This is 
acceptable as long as gilts are fed and managed alike.) 
3. When the gilts weigh 180 to 220 pounds and are still 
on full feed, separate the ear-notched gilts from the rest of the 
herd. Eliminate off-type or undersized gilts. Weigh the good 
gilts and adjust their weights to a 154-day age basis, using 
the chart on page 9. 
4. As the gilts come from the scales, probe for backfat thick- 
ness, using a small steel ruler. Instructions for probing are on 
pages 6 and 7. Adjust these probes to a 200-pound basis, 
11sing the chart on page 10. 
5. Make Final Selection of Gilts on: 
* Litter records 
Gaining ability 
Backfat probe 
Visual appraisal 
Adequate length and depth of body; long, thick 
hams; strong, clean top-lines; firm, meaty shoul- 
ders; and trim, firm underlines 
Sound feet and legs 
A minimum of 12 evenly spaced, functional nipples 
Absence of physical defects 
Rear view of a well-muscled, meaty gilt. Observe the clean 
topline (nice turn over the top) at (A)  and the thick, heavy 
muscled hams as seen at ( B ) .  Also note the width of ham in 
relation to width of back. The gilt's feet and legs are on the 
corners and wide apart as shown at ( C ) .  
Plan B - For the Purebred Breeder 
1. Follow the Production Registry program. 6. Select breeding animals using all information 
available on : 
2. Participate in the breed Meat-Type Certifi- 
Litter records 
cation program. 
Gaining ability 
3. Participate in the Breed Association "On-the- 
- 
Backfat probe 
Farm" Performance Testing Program and Litter 
Carcass data from littermates Testing Demonstrations at central stations. 
Feed conversion records I' . 
4. Obtain feed ionversion data on as many lit- Visual appraisal 
ten as possible. The following are recommended standards to 
5. Weigh and probe all boars and gilts at ap- remember when selecting breeding animals: 
proximately 200 pounds from which replacement Litter size- 
and sale animals are to be selected. At least 10 farrowed, eight or more weaned 
154-day weight- Accurate records are necesary in any swine ~ I I I .  
Gilts, at least 200 pounds provement program. D-525, a S o w  Record Form 
Boars, at least 220 pounds appears on page 11 and D-524, a Weight and 
200-pound backfat- Probe Record Form,  is on page 8. Additional cople\ 
Gilts, 1.2 inches or less of these forms can be obtained fromr your locnl 
Boars, 1.0 inches or less county agricultural agent. 
Making the Backfat Probe 
Equipment needed: Hog snare, knife or scalpel blade and metal 
Where to Probe 
1. I'robe behind the shoulder, straight above the elbow. 2. Probe 
at  the last rib. 3. Probe iiiitlway between the last rib and the base 
of the tail. 
ruler measured in tenths of in ches. 
All measurements are made approxiniately 2 inches from the 
midline of the pig's back. 
How to Probe 
1. Illrap knife blade or scalpel blade with tape 
about 3/8 inch from tip. (The tape prevents the 
bla '* from going too deep.) 
'2. Restrain hog with a nose snare. 
3. Jab knife sharply through skin at right angle 
to hog's body. 
4. Insert the ruler in the cut, slanting it to make 
a !I0 degree angle to the pig's back. 
Seventh rib. (Probe behind the shoulder, ~traight above the 5. In one decisive push, force the ruler through back of the front leg.) 
the fat to the muscle. 
6. Push the clip on the ruler down to the skin. 
Re sure that no downward pressure is being ap- 
plied to the ruler, but that it is resting firmly against 
the muscle tissue. Remove ruler and read the meas- 
urement. 
7 .  For most accurate results, make probe meas- 
urements at three locations on both sides of the pig 
or n total of six probes. 
8. Total the six measurements and divide by six 
to determine the average backfat depth. 
9. The Probe Adjustment Table on page 10 con- 
verts the average backfat probe measurements on 
each hog to a common 200-pound weight. 
The cross-section pictures on  this page show the 
n~urcle and fat relationship at each probe location. 
There is little chance for error when making the 
probes at the last rib and last lumbar region be- 
came )ou are probing down to solid muscle tissue. 
Because of muscle structure in the shoulder region, 
however, there is chance for error unless the proper 
technique is used. The muscle that the end of the 
steel ruler is touching in the cross section at the 
se~enth rib is called the trapezius muscle. This 
muscle varies in thickness among individual hogs. 
One can probe through the trapezius muscle to the 
second lean muscle without realizing it. For this 
reason, most accurate results are obtained by mak- 
Ing probe measurements at each of the three loca- 
tlons on both sides of the hog. If there is as much  
ns .3 of an inch variation between the shoulder 
probes on either side, probes should be made again 
to determine the correct fat thickness. 
Last rib. (Probe at last rib.) 
Last lurnbar region. (Probe midway bcttvccn the last rib 
and the tail. l 
Using the Backfat Probe 
T o  make a reliable comparison among indi- 
vidual animals, all must have been fed and man- 
aged alike. 
T o  estimate most accurately the meatiness of 
gilts and boars and to predict their future perform- 
ance, backfat probes should be made at  180 to 220 
pound 
grain a 
weights, while the hogs are on a self-fed less than gilts, and gilts normally probe less tha~l  
nd supplement ration. barrows. Research indicates that the following dif- 
ference in backfat thickness among littermates ma! 
Because of sex influence, boars normally probe be expected at 200-pound weights : 
~' .I 
' L 
BACKFAT THICKNESS DUE 
HOGS WITHIN A LITTER TO SEX DIFFERENCE, INCH 
Boars. . . . . . . . . . . . . . . . . . .  .About . l  less than gilts 
About .2 less than barrows 
Gilts. . . . . . . . . . . . . . . . . . . .  .About . l  less than barrows 
About .1 more than boars 
Barrows. . . . . . . . . . . . . . . . .  .About . l  more than gilts 
About .2 more than boars 
This means that a boar has to be more than .1 of an inch less than the gilts in backfat probe if 
progress is to be expected. 
Ear - Notching System 
Litter mark:  Use right ear. All pigs in same lit- 
ter  nus st have the same ear notches in this ear. 
81 
Individual pig marks: Left ear is used to show 
individual pig within a litter. Each pig will have 
different notches in this ear. 
I 
Take full notch in baby pig's ear so notch will 
be clearly visible, and not grow shut. 
I 
Notching pigs as soon as possible after farrowing 
will prevent errors. 
.., .. 
T o  avoid mistaking a "3" notch for a "1" notch 
for vice versa) do not notch in dark area of ear. 
RIGHT LEFT 
Right ear-litter number 
Left ear-Pig number 
I 
WEIGHT and PROBE RECORD (Sample) D m 5 2  
irks. , 
200-1 b. 
adj. 
1.14 
Remc 
No. I 5 u w ,  , 
34 ib. at 6 wit 
7 
I 
Sex 
F 
Ear 
Mark 
Example 
Age 
i n  
days 
148 
Hog 
No. 
IS+-day 
adj.wt. 
( l b . )  
2 0 3 .  
1 
Actual  
w t .  
(1b.I  
192. I 1 V
-7 
e 
e 
P R O B E  
( i nches) 
Shl dr. 
L- 1.3 
R- 1.4 
L- 
R- 
L- 
R- 
L- 
Av . 
probe 
1.10 
L a s t  
r i b  
1.0 
0.9 
L a s t  
lumbar 
1.0 
1.0 
C 
F 240 
- 
A d j u s t e d  W e i g h t  f o r  1 5 4  D a y s  o f  Ag 
Lay a straightedge from the  actual  weight as 
read on the  lef% hand scale  t o  the  age a t  weighing 
on the  center scale .  The straightedge w i l l  give 
the  154 day adjusted weight on the  r i gh t  hand 
s cale . 
J. A. Whatley 
Oklahoma S ta t e  University - 
ACTUAL 
WEIGHT 
pounds 
A d j u s t i n g  P r o b e  t o  a 2 0 0 - P o u n d  B a s i s  
EQUIVALENT 
PROBE AT 
200 POUNDS 
inches 
DIRECTIONS: Lay a ru ler ,  o r  other 
straightedge, f rom the figure repre -  
senting the weight of the pig, a s  read 
on the left-hand scale,  to the figure 
for  the depth of the probe, a s  read on 
the right-hand scale. The point where 
this line inter sects  the center scale 
shows the equivalent probe at 200 
pounds. 
Hi W. Bean 
University of Illinois 
ACTUAL 
- : 6 DEPTH OF 
PROBE 
inches 
I 
S O W  R E C O R D  
Sow No. 
Sow's l i t ter 
( I  , Z,,.etc.) Ear notches 
Birth date of sow 
180-day wt-00 Ib. prob-FeedllOO Ib. gain 
Farrowing date 
Total farrowed ....................... .Male F e m a l ~  
Farrowed alive ........................ Male F e m a l a  
......................... Total weaned .Male Femal- 
day l itter wt. 
21, 35, 56, etc. 
Name Reg. No. BOAR NO. 
Av. 154-day Wt. of litter- Feed per 100  pounds gain 
Breed BREED 
I Ear Notch 
C 
i R I  
Backfat Probe 
=I+*- 
Age weighed 
d a y s  
Actual 
Wt. 
- 
Birth Weoning 
Weight Weight 
(Optional) 
- 
Pig 
No. 
-- 
Adi. 154 
day wt. 
-
tHTp-- 
Av. 
In. 
- 
i n  
In. 
Shldr. 
In. 
Sex 
4 
Adj. to  Remarks 
200 Ib. 
Back 
In. 
PRODUCTION TESTED BOARS 
MATED TO 
* 
ON-THE-FARM SELECTED GILTS 
GIVE 
* 
MAXIMUM POUNDS OF DESIRABLE 
PORK AT MINIMUM COST 
Cooperative Extension Work in Agriculture and Home Economics, Texas A&M University and United States Department 
of Agriculture cooperating. Distributed in furtherance of the Acts of Congress of May 8, 1914, as amended, and June 30, 1914. 
10M-1-71, Reprint AS 6-1 


English

Selecting Meatier Hogs.

Texas A&amp;M Repository

'EX TEXAS A&M AGRICULTURAL .. HUTCHISON. DIRECT OF^ ;$d * >-. UNIVERSITY EXTENSION SERV I. COLLEGE STATION. TEXAS *Wn-the-FarmN Pmmmce  Full imfomtation qn this pr;ogrgm can bs &wined from your laool w n t y  t o l d  agsnt or Extandon Swine Speclalist at TOXQI A M I  University. FOR THE COMMERCIAL PRODUCER 1. Choose and follow a breeding plan. Hybrid vigor is of much importance in commercial hog production. Rotation of purebred boars of three breeds is an effective practice for utilizing the principle of hybrid vigor. Choose breeds that provide the best combination of traits in their crosses. 2. Select and use purebred boars from production-tested stock. Insist on rate of gain, feed efficiency and carcass information when buying boars. Purebred breeders participating in one of the testing programs outlined will have boars with this infor- mation. 3. Select the most efficient, meatiest gilts for replacements. The "ON-THE-FARM" selection program based on litter records, rate of gain and meatiness as determined by "backfat probing" is outlined in this publication to help select the best gilts. Selecting Meatier Hogs T. D. Tanksley, Jr. Associate Professor and Extension Swine Specialist Texas A@M University T EXAS SWINE PRODUCERS can produce more muscular hogs with less fat by following a planned selection and breeding program. Such hogs are more valuable on today's market and their lean, tender cuts find favor with American house- wi\.cs. This meatier hog can be produced by selecting gilts and boars that have adequate length (30-inch carcass on a 200-pound hog) with thick, muscular conformation, with just enough fat at market weight to insure carcass firmness and give quality and flavor to the cuts. This meatier hog must come from sows that farrow and raise large litters of big pigs; he must be fast growing, be able to convert qrain and supplement into pounds of pork at an efficient rate and possess other traits that mean profit for the producer. Any profitable selection program must be based on the ability of an animal to perform. This opin- ion is reflected in the wider acceptance and use of Production Registry, breed Meat-Type Certifica- tion Programs, "On-the-Farm" Performance Test- ing and Gilt Selection Programs. , No single selection plan fits all breeders and pro- ducers, but sound production information coupled with competent visual appraisal permits the most accurate selection of breeding animals. The commercial producer, by selecting produc- tion-tested boars and mating them to "On-the- Farm" selected gilts, as outlined in this publication, will produce meat-type hogs most efficiently. The .* commercial producer should buy boars from breed- ers that have satisfactory litter records, rate-of-gain, feed efficiency and carcass cut-out information on them. Extra time, effort and money spent in select- ing boars generally give the greatest return of any investment you make in the hog business. Attempt to buy boars from breeders participating in one of the testing programs described inside the front cover. Always try to evaluate as many of the litter- mates and close kin of your boar as possible to help get a more dependable estimate of his potential. Selecting Gilts The success of the purebred breeder and com- mercial producer is greatly influenced by their abil- ity to select and retain the most productive gilts in their breeding herd. The following "On-the-FarmJ' selection program is one of the most highly effec- tive programs for selecting more muscular, more profitable gilts. This program supplements pure- bred selection programs and serves as a guide for commercial and purebred swine producers. The program @ based on the basic fundamentals that are of greatest economic importance to swine producers : 1. Sow productivity Large litters of thrifty pigs raked to weaning are Cross sections of the loin at tenth rib of a meat-type hog (left) and a fat-type (right). The meat-type not only has the first essential to a profitable pork program. less fat, but more red meat (muscle). Replacement animals should be selected only within the breeds that are really "meaty" anti from the largest, heaviest litters. use them in his breeding program. 2. Rapid,  ef icient growth Rapidly growing hogs which reach 200 pounds at 5 to 6 months of age are normally cheaper to produce than slower growing hop.  Therefore, some measure of the pig's .ability to gain should be included in the selection program. 3. 'cMeatiness" Amount of muscling is the most important cri- terion in determining whether a hog is truly meat-type. Only market ho,q with good muscling and with a high lean-to-fat ratio are truly meat- type. Meat-type hogs can be found in all breeds of ?wine. The breeder muyt find those strains Muscling or "meatiness" is difficult to evaluate on the live hog by visual inspection alone. The backfat probe enables the producer to make more accurate selections for meatiness. The iverage bach- fat thickness, as determined by the live-prohr method, is the best measurement that is presenth available for estimating the amount of musclinc and meatiness in the live animal. After the average backfat thickness has been measured accurately on the live hog, a producer can appraise meatiness in measured animals by comparing their relative bod1 thickness and amount of backfat thickness. The general plan for carrying out this "On-the- FarmJ' selection program follows : Plan A-For the Commercial Producer 1. Ear-notch the gilt pigs in big litters at birth. (Give each litter a different ear notch. Record ear notch and farrowing date of each litter. See page 8 for simple ear-notching sys- tem. To get as much information on each sow as possible, it is advisable to ear-notch all pigs in all litters at birth and weigh all pigs at 35 or 56 days.) 2. Place the gilts on full feed at weaning time. Leave them on a high energy ration until they weigh 180-220 pounds. This practice permits the gilts to display their inherent tend- ency to be meaty or overfat. (Some producers may desire to separate the better looking gilts from the rest of the herd at 125-150 pounds and feed them a more bulky ration. This is acceptable as long as gilts are fed and managed alike.) 3. When the gilts weigh 180 to 220 pounds and are still on full feed, separate the ear-notched gilts from the rest of the herd. Eliminate off-type or undersized gilts. Weigh the good gilts and adjust their weights to a 154-day age basis, using the chart on page 9. 4. As the gilts come from the scales, probe for backfat thick- ness, using a small steel ruler. Instructions for probing are on pages 6 and 7. Adjust these probes to a 200-pound basis, 11sing the chart on page 10. 5. Make Final Selection of Gilts on: * Litter records Gaining ability Backfat probe Visual appraisal Adequate length and depth of body; long, thick hams; strong, clean top-lines; firm, meaty shoul- ders; and trim, firm underlines Sound feet and legs A minimum of 12 evenly spaced, functional nipples Absence of physical defects Rear view of a well-muscled, meaty gilt. Observe the clean topline (nice turn over the top) at (A)  and the thick, heavy muscled hams as seen at ( B ) .  Also note the width of ham in relation to width of back. The gilt's feet and legs are on the corners and wide apart as shown at ( C ) .  Plan B - For the Purebred Breeder 1. Follow the Production Registry program. 6. Select breeding animals using all information available on : 2. Participate in the breed Meat-Type Certifi- Litter records cation program. Gaining ability 3. Participate in the Breed Association "On-the- - Backfat probe Farm" Performance Testing Program and Litter Carcass data from littermates Testing Demonstrations at central stations. Feed conversion records I' . 4. Obtain feed ionversion data on as many lit- Visual appraisal ten as possible. The following are recommended standards to 5. Weigh and probe all boars and gilts at ap- remember when selecting breeding animals: proximately 200 pounds from which replacement Litter size- and sale animals are to be selected. At least 10 farrowed, eight or more weaned 154-day weight- Accurate records are necesary in any swine ~ I I I .  Gilts, at least 200 pounds provement program. D-525, a S o w  Record Form Boars, at least 220 pounds appears on page 11 and D-524, a Weight and 200-pound backfat- Probe Record Form,  is on page 8. Additional cople\ Gilts, 1.2 inches or less of these forms can be obtained fromr your locnl Boars, 1.0 inches or less county agricultural agent. Making the Backfat Probe Equipment needed: Hog snare, knife or scalpel blade and metal Where to Probe 1. I'robe behind the shoulder, straight above the elbow. 2. Probe at  the last rib. 3. Probe iiiitlway between the last rib and the base of the tail. ruler measured in tenths of in ches. All measurements are made approxiniately 2 inches from the midline of the pig's back. How to Probe 1. Illrap knife blade or scalpel blade with tape about 3/8 inch from tip. (The tape prevents the bla '* from going too deep.) '2. Restrain hog with a nose snare. 3. Jab knife sharply through skin at right angle to hog's body. 4. Insert the ruler in the cut, slanting it to make a !I0 degree angle to the pig's back. Seventh rib. (Probe behind the shoulder, ~traight above the 5. In one decisive push, force the ruler through back of the front leg.) the fat to the muscle. 6. Push the clip on the ruler down to the skin. Re sure that no downward pressure is being ap- plied to the ruler, but that it is resting firmly against the muscle tissue. Remove ruler and read the meas- urement. 7 .  For most accurate results, make probe meas- urements at three locations on both sides of the pig or n total of six probes. 8. Total the six measurements and divide by six to determine the average backfat depth. 9. The Probe Adjustment Table on page 10 con- verts the average backfat probe measurements on each hog to a common 200-pound weight. The cross-section pictures on  this page show the n~urcle and fat relationship at each probe location. There is little chance for error when making the probes at the last rib and last lumbar region be- came )ou are probing down to solid muscle tissue. Because of muscle structure in the shoulder region, however, there is chance for error unless the proper technique is used. The muscle that the end of the steel ruler is touching in the cross section at the se~enth rib is called the trapezius muscle. This muscle varies in thickness among individual hogs. One can probe through the trapezius muscle to the second lean muscle without realizing it. For this reason, most accurate results are obtained by mak- Ing probe measurements at each of the three loca- tlons on both sides of the hog. If there is as much  ns .3 of an inch variation between the shoulder probes on either side, probes should be made again to determine the correct fat thickness. Last rib. (Probe at last rib.) Last lurnbar region. (Probe midway bcttvccn the last rib and the tail. l Using the Backfat Probe T o  make a reliable comparison among indi- vidual animals, all must have been fed and man- aged alike. T o  estimate most accurately the meatiness of gilts and boars and to predict their future perform- ance, backfat probes should be made at  180 to 220 pound grain a weights, while the hogs are on a self-fed less than gilts, and gilts normally probe less tha~l  nd supplement ration. barrows. Research indicates that the following dif- ference in backfat thickness among littermates ma! Because of sex influence, boars normally probe be expected at 200-pound weights : ~' .I ' L BACKFAT THICKNESS DUE HOGS WITHIN A LITTER TO SEX DIFFERENCE, INCH Boars. . . . . . . . . . . . . . . . . . .  .About . l  less than gilts About .2 less than barrows Gilts. . . . . . . . . . . . . . . . . . . .  .About . l  less than barrows About .1 more than boars Barrows. . . . . . . . . . . . . . . . .  .About . l  more than gilts About .2 more than boars This means that a boar has to be more than .1 of an inch less than the gilts in backfat probe if progress is to be expected. Ear - Notching System Litter mark:  Use right ear. All pigs in same lit- ter  nus st have the same ear notches in this ear. 81 Individual pig marks: Left ear is used to show individual pig within a litter. Each pig will have different notches in this ear. I Take full notch in baby pig's ear so notch will be clearly visible, and not grow shut. I Notching pigs as soon as possible after farrowing will prevent errors. .., .. T o  avoid mistaking a "3" notch for a "1" notch for vice versa) do not notch in dark area of ear. RIGHT LEFT Right ear-litter number Left ear-Pig number I WEIGHT and PROBE RECORD (Sample) D m 5 2  irks. , 200-1 b. adj. 1.14 Remc No. I 5 u w ,  , 34 ib. at 6 wit 7 I Sex F Ear Mark Example Age i n  days 148 Hog No. IS+-day adj.wt. ( l b . )  2 0 3 .  1 Actual  w t .  (1b.I  192. I 1 V-7 e e P R O B E  ( i nches) Shl dr. L- 1.3 R- 1.4 L- R- L- R- L- Av . probe 1.10 L a s t  r i b  1.0 0.9 L a s t  lumbar 1.0 1.0 C F 240 - A d j u s t e d  W e i g h t  f o r  1 5 4  D a y s  o f  Ag Lay a straightedge from the  actual  weight as read on the  lef% hand scale  t o  the  age a t  weighing on the  center scale .  The straightedge w i l l  give the  154 day adjusted weight on the  r i gh t  hand s cale . J. A. Whatley Oklahoma S ta t e  University - ACTUAL WEIGHT pounds A d j u s t i n g  P r o b e  t o  a 2 0 0 - P o u n d  B a s i s  EQUIVALENT PROBE AT 200 POUNDS inches DIRECTIONS: Lay a ru ler ,  o r  other straightedge, f rom the figure repre -  senting the weight of the pig, a s  read on the left-hand scale,  to the figure for  the depth of the probe, a s  read on the right-hand scale. The point where this line inter sects  the center scale shows the equivalent probe at 200 pounds. Hi W. Bean University of Illinois ACTUAL - : 6 DEPTH OF PROBE inches I S O W  R E C O R D  Sow No. Sow's l i t ter ( I  , Z,,.etc.) Ear notches Birth date of sow 180-day wt-00 Ib. prob-FeedllOO Ib. gain Farrowing date Total farrowed ....................... .Male F e m a l ~  Farrowed alive ........................ Male F e m a l a  ......................... Total weaned .Male Femal- day l itter wt. 21, 35, 56, etc. Name Reg. No. BOAR NO. Av. 154-day Wt. of litter- Feed per 100  pounds gain Breed BREED I Ear Notch C i R I  Backfat Probe =I+*- Age weighed d a y s  Actual Wt. - Birth Weoning Weight Weight (Optional) - Pig No. -- Adi. 154 day wt. -tHTp-- Av. In. - i n  In. Shldr. In. Sex 4 Adj. to  Remarks 200 Ib. Back In. PRODUCTION TESTED BOARS MATED TO * ON-THE-FARM SELECTED GILTS GIVE * MAXIMUM POUNDS OF DESIRABLE PORK AT MINIMUM COST Cooperative Extension Work in Agriculture and Home Economics, Texas A&M University and United States Department of Agriculture cooperating. Distributed in furtherance of the Acts of Congress of May 8, 1914, as amended, and June 30, 1914. 10M-1-71, Reprint AS 6-1 

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Selecting Meatier Hogs.

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Selecting Meatier Hogs.

Abstract

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Texas A&M University

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