y, . 
+? BULLETIN 1381, U. S. DEPARTMENT OF AGRICULTURE 
TaBLE 5.—Relation of number of pigs weaned per sow bred to the gross cost of 
maintaining the breeding herd, per pig weaned and the gross cost of 100 pounds 
of pork 
1921 1922 
mekeséelariny : Gross cost Gross cost 
um 
er of pigs weaned per sow bred Number SCE Lai el ARIS PR TRC AI 3 AA? 
9) of 
droves! | Per pig s feo droves! | Per pig eergae 
weaned pork weaned pork 
One litter per year: 
Phy tae Ne A sc eh ye oe ah pes Sete Sear 11 $6. 68 $6. 56 4 $8. 12 $7. 82 
GOO Pas bs oe A Pelt he of Grid TN ll 4.44 5. 30 9 3. 85 6. 40 
Dae ie ite ta 6 3. 38 4. 60 2 3. 33 5. 41 
Two litters per year: 
OGG idie MEADE oe make Ab eee 3 4. 81 6. 58 4 4. 59 6. 65 
PUM Me se ee a BA TT ee eh ee eee 6 3. 87 5. 78 10 3. 36 6. 25 
1) 77h SS eee ee Oe ROR See Poor ess SY 6 3. 07 5. 13 8 2:75 6. 82 
1 System of hog management on one farm in 1921 and two farms in 1922 did not permit recording exact 
number of sows bred for fall litters. These farms are not included in this table. 
The cost per sow should be kept as low as is consistent with large 
litters to give the greatest advantage to the pigs. A desire to reduce 
the cost of maintenance may result in the insufficient nutrition of the 
gestating sows. Under these conditons the litters may be small and 
contain dead and weak pigs. The reverse may also be true; that in 
an endeavor to raise large, strong, healthy litters the breeding herd 
may be given unnecessarily expensive feeds resulting in a higher cost 
of maintenance and no greater herd performance. The varying 
results which different producers obtained, as found in this study, 
seem to indicate that success does not depend upon any one method. 
Any system of management or feeding is inadequate unless accom- 
panied by forethought and patient care on the part of the herdsman, 
which seem to be compensated by savings resulting from more efficient 
production. 
The cost of carrying the breeding herd, as presented in this study, 
included the period of the production year, or from the time the sows 
were selected for spring-pig breeding to the time of breeding for spring 
igs the following year. The feed charged includes that fed to the 
oe while they were on the farm and to the sows during the gesta- 
tion, suckling, and fattening periods in case some of the sows were 
sold. Many causes of variation in the cost of maintaining the breed- 
ing herd are evident, such as length of time on the farm, the weight 
and amount of gain put on the breeding herd, character of ration fed, 
price of feeds, number of pigs suckled, and the length of the suckling 
eriod. 
An explanation of the cost of maintenance per sow will aid in com- 
paring thésb costs. The number of sows bred during the year was 
used as the basis for computing the cost of maintenance per sow. 
The length of time on the farm, which has a large influence on the cost 
er sow, is influenced by the number of sows sold early in the year 
owas of barrenness or abortions, and the proportion of the breeding 
herd which is rebred for fall litters. In some of the data the cost is 
presented per sow per month to eliminate the effect of time. The 
‘cost of keeping the boar while he was on the farm is included among 
the items making up the cost per sow, 
