• TABLE OF CONTENTS
HIDE
 Experimental
 Results and discussion
 Summary
 References
 Table 1 - Effect of parity on sow...
 Table 2 - Effect of season of farrowing...
 Table 3 - Effects of season X parity...














Group Title: Department of Animal Science research report - Florida Agricultural Experiment Station ; AL-1983-6
Title: Effects of season and parity on sow productivity
CITATION PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00073151/00001
 Material Information
Title: Effects of season and parity on sow productivity
Series Title: Department of Animal Science research report
Physical Description: 6 p. : ; 28 cm.
Language: English
Creator: Coffey, M. T
Olson, T. A ( Timothy A )
Combs, G. E ( George Ernest ), 1927-
University of Florida -- Dept. of Animal Science
University of Florida -- Agricultural Experiment Station
Publisher: Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1983
 Subjects
Subject: Sows -- Productivity -- Florida   ( lcsh )
Sows -- Reproduction -- Effect of temperature on -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 4).
Statement of Responsibility: M.T. Coffey, T.A. Olson and G.E. Combs.
General Note: Caption title.
General Note: "August, 1983."
General Note: Pages numbered 28-33.
Funding: Animal science research report (University of Florida. Dept. of Animal Science) ;
 Record Information
Bibliographic ID: UF00073151
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 82142485

Table of Contents
    Experimental
        Page 28
    Results and discussion
        Page 29
        Page 30
    Summary
        Page 31
    References
        Page 31
    Table 1 - Effect of parity on sow productivity
        Page 32
    Table 2 - Effect of season of farrowing on sow productivity
        Page 32
    Table 3 - Effects of season X parity on the number of pigs born
        Page 33
Full Text





Department of Animal Science Florida Agricultural
Research Report AL-1983-6 -28- Experiment Station
August, 1983 Gainesville, FL

EFFECTS OF SEASON AND PARITY ON SOW PRODUCTIVITY

M. T. Coffey, T. A. Olson and G. E. Combs1


Sow productivity is one of the most important factors affecting the
profits of the swine producer. Understanding the causes of variation in sow
productivity is important so that management decisions that will provide
maximum efficiency can be made. Factors such as season of the year and
parity are known to affect sow productivity as measured by litter birth, and
weaning weights, number born alive and number surviving to weaning.
Seasonal temperature extremes are different between geographic locations;
therefore, the effects of season on sow productivity may vary between areas
of the country. The purpose of this report is to examine causes of
variation in sow productivity in Florida.

Experimental

Data were collected from the breeding herd at the University of Florida
Swine Research Center in Gainesville. The three breed terminal
crossbreeding program utilized Duroc, Hampshire and Yorkshire breeds.
Replacement females including purebred Duroc gilts were saved from the herd.
The data presented here includes crossbred females from a 2 year period.

Approximately five days prior to farrowing sows were brought to the
farrowing barn, washed, weighed and placed in individual crates. Crates had
a combination solid wood slatted floor and a heat lamp was provided for
the pigs. After farrowing pigs were weighed, ear notched and their needle
teeth were cut. By three days of age all pigs were given iron shots (iron
dextran), and the males were castrated.

Litters were weaned at 21 days of age to a environmentally controlled
nursery and sows were placed in outside breeding pens. After breeding,at
the first post-weaning estrus, gestation proceeded in dirt lot pens. Each
pen contained a covered shelter, individual sow feeding stalls, and
automatic waterer.

Data were summarized by parity (1-4), sows having 4 or more litters
were grouped into parity 4, and by season of farrowing: 1. December-
February; 2. March-April; 3. May-June; 4. July-September; 5.
October-November. Data were analyzed by least squares analysis of variance
to examine the influence of season, parity and interactions. If analysis of
variance indicated a significant effect or the interaction was significant,
the least squares means procedure was used to separate means.

1Coffey, Assistant Animal Nutritionist, Olson, Assistant Animal Breeder and
Combs, Animal Nutritionist, Animal Science Department, Gainesville.







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Results and Discussion

The effects of parity across all seasons on the number of pigs
born/litter, number of pigs weaned/litter, percent surviving to weaning,
birthweights, 14 day weight and weaning weights are summarized in Table 1.
First and second litter sows farrowed fewer (P<.05) pigs/litter than third
or fourth parity sows. Parity did not affect the number weaned/litter.
Sows in parity 1, 2 and 3 had higher (P<.05) pig survival rates than parity
4 sows. Birthweight for parity 1 litters was lower (P<.05) than parities 3
or 4. While birthweight for parity 2 litters was lower than for parity 4.
There were no significant differences due to parity (P<.05) in litter 14-day
or weaning weights.

Previous data have demonstrated that as sows mature they tend to
increase the number of ova released at ovulation and therefore conceive and
farrow larger litters. This effect is confirmed by these data. The
survival rate tended to decline through the first 3 parities. The
difference was significantly (P<.05) lower in sows farrowing 4 or more
litters. The fact that sows in this group farrowed the largest litters and
therefore would provide more opportunities for pigs to die may account in
part for the poorer survival rate. Also, data for sows in this group
included older sows (>4 parities) which were subsequently culled from the
herd due to sub-optimal performance.

The fact that younger sows (parity 1 and 2) farrowed fewer pigs/litter
resulted in lower litter birthweights. Parity 3 and 4 sows had heavier
litters than parity 1 sows, and parity 2 litters weighed less than parity 4
litters at birth. However, sow productivity, as measured by weight of the
litter at weaning, was not affected by parity. Older sows farrowed more
pigs but survival rate was lower. This resulted in a similar number of pigs
weaned/litter and litter weaning weights that were similar among all
parities.

The effects of season of farrowing across all parities on parameters
reflecting sow productivity are summarized in Table 2. There were less
(P<.05) pigs/litter born in season 1 (P<.05) than any other season. The
number of pigs weaned was less (P<.05) with litters born in seasons 1 and 3
than those born in seasons 2 and 4. Survival of pigs to weaning was greater
(P<.05) in season 1 than seasons 3, 4 or 5. Birthweight of litters in
seasons 3, 4 and 5 were heavier (P<.05) than for litters farrowed during
season 1. Litter weights at day 14 were less in season 3 than seasons 2, 4
and 5, and litters born in season 3 weighed less (P<.05) at weaning than
litters born in any other season. Litters in season 2 were heavier at
weaning than season 1.

These data illustrate the effects of seasonal temperature variation on
sow productivity. Decreased litter size at birth may be attributed to late
summer breeding (August to October) and the corresponding season 1
(December-February) farrowings. Heat stress of boars has been shown to







-30-
result in lowered fertility and smaller litters from sows which do conceive
(Wettemann et al., 1976). Research in Florida indicated that heat stress
resulted in reduced semen motility from July to mid October (Wettemann et
al., 1982). Further, heat stress may increase embryonic mortality,
particularly during early gestation before implantation of the embryos to
the uterine wall has occurred. Survival of pigs farrowed during season 1
was highest of all seasons. This was likely due to the fact that litters
were smaller at birth and to the effects of seasonal variation on the sow's
lactation performance. Litters born from May to September (seasons 3 and 4)
had the poorest survival to weaning. This was during the long period of
warm temperatures in Florida and resulted in detrimental effects on
survival. As the cooler season approached (season 5) survival improved,
although not to the rate of the winter months (season 1). During periods of
high temperature stress (seasons 3 and 4) sows may decrease their feed
consumption and therefore energy intake. This would result in decreased
lactation performance, which is reflected in fewer pigs surviving to
weaning. Other factors such as sow restlessness caused by the discomfort of
high temperatures may increase the number of pigs stepped on or overlain by
the sow.

Sow productivity, as determined by litter weights reflected the effects
of season on the number of pigs born/litter and survival to weaning. The
decreased survival of litters from season 3 resulted in the lightest (P<.05)
weaning weights. Although lighter than all other seasons at birth, the
season 1 litters differed only from those in season 2 at weaning. This was
due to the fact that litters born in season 1 had the best survival rate.
The combination of number of pigs born/litter (11.31) and a good survival
rate (89.72) resulted in the heaviest weaning weights from litters born in
season 2.

There were significant (P<.05) season by parity interactions for the
number of pigs/litter, number weaned/litter, birth weight, 14 day weight and
weaning weights. The season by parity effects on number of pigs/litter is
summarized in Table 3. There was no effect of season on the number of pigs
farrowed by parity 1 or 4 sows. In contrast, second and third parity sows
farrowed significantly (P<.05) smaller litters during season 1 compared to
all other seasons.

The data indicated that second and third litter sows were affected the
most by late summer and fall breeding (season 1 farrowing). The effect
was particularly severe in the second parity. Sows in this group were
gilts farrowing their first litter during the summer. The effects of heat
stress during the summer in combination with the first lactation may
have may have resulted in a poor condition at breeding that led to the
smaller litters in the second parity. This suggests that extra care should
be taken with gilts farrowing during the summer. Adequate feed should be
provided to be sure that these gilts come through lactation in good
condition for rebreeding.

The other significant interactions are due to the effects on litter
size. The reduced number of pigs farrowed/litter by first and second parity
sows during season 1 led to lighter birth, 14 day and weaning weights, and
to fewer pigs/litter at weaning.







-31-


Summary

Breeding herd data from the University of Florida Swine Research Center
in Gainesville were examined to investigate causes of variation in sow
productivity in Florida. The data were summarized by parity (1-4) and
season of farrowing (1. December-February; 2. March-April; 3. May-June; 4.
July-September; 5. October-November). First and second parity sows farrowed
fewer (P<.05) pigs/litter than third or fourth parity sows. Sows in parity
1, 2 and 3 had higher (P<.05) pig survival to weaning than parity 4 sows.
There was no difference in the number of pigs weaned/litter. More pigs at
birth resulted in heavier (P<.05) litter weights for older sows, but the
poorer survival rates resulted in day 14 and weaning weights which were
similar for all parities. There were less (P<.05) pigs/litter born in
season 1 than any other season. The number of pigs weaned was decreased
(P< .05) from litters born in seasons 1 and 3 compared to those born in
seasons 2 or 4. Survival of pigs to weaning was greater (P<.05) in season 1
than seasons 3, 4 or 5. Decreased litter size at birth resulted from late
summer breeding and the cooresponding season 1 farrowings. Litters born
during the hot seasons (3 or 4) had the poorest survival to weaning. Litter
weights reflected the number of pigs/litter and survival to weaning.
Litters from season 3 had the lightest (P<.05) litter weaning weights and
litters from season 2 the heaviest (P<.05). There were significant season x
parity interactions. There was no effect of season on the number of
pigs/litter from parity 1 or 4 sows. In contrast, second and third parity
sows had significantly (P<.05) smaller litters during season 1 compared to
all other seasons.

References

1. Wettemann, R. P., M. E. Wells, I. T. Omtvedt, C. E. Pope and E. J.
Turman. 1976. Influence of elevated ambient temperature on
reproductive performance of boars. J. Anim. Sci. 42:664.

2. Wettemann, R. P., C. E. White, and F. W. Bazer. 1983. Influence of
heat stress on semen quality and respiratory rates of boars in Florida
and Oklahoma. Univ. of Florida, Live Oak ARC Res. Rep. SW-1982-83.







-31-


Summary

Breeding herd data from the University of Florida Swine Research Center
in Gainesville were examined to investigate causes of variation in sow
productivity in Florida. The data were summarized by parity (1-4) and
season of farrowing (1. December-February; 2. March-April; 3. May-June; 4.
July-September; 5. October-November). First and second parity sows farrowed
fewer (P<.05) pigs/litter than third or fourth parity sows. Sows in parity
1, 2 and 3 had higher (P<.05) pig survival to weaning than parity 4 sows.
There was no difference in the number of pigs weaned/litter. More pigs at
birth resulted in heavier (P<.05) litter weights for older sows, but the
poorer survival rates resulted in day 14 and weaning weights which were
similar for all parities. There were less (P<.05) pigs/litter born in
season 1 than any other season. The number of pigs weaned was decreased
(P< .05) from litters born in seasons 1 and 3 compared to those born in
seasons 2 or 4. Survival of pigs to weaning was greater (P<.05) in season 1
than seasons 3, 4 or 5. Decreased litter size at birth resulted from late
summer breeding and the cooresponding season 1 farrowings. Litters born
during the hot seasons (3 or 4) had the poorest survival to weaning. Litter
weights reflected the number of pigs/litter and survival to weaning.
Litters from season 3 had the lightest (P<.05) litter weaning weights and
litters from season 2 the heaviest (P<.05). There were significant season x
parity interactions. There was no effect of season on the number of
pigs/litter from parity 1 or 4 sows. In contrast, second and third parity
sows had significantly (P<.05) smaller litters during season 1 compared to
all other seasons.

References

1. Wettemann, R. P., M. E. Wells, I. T. Omtvedt, C. E. Pope and E. J.
Turman. 1976. Influence of elevated ambient temperature on
reproductive performance of boars. J. Anim. Sci. 42:664.

2. Wettemann, R. P., C. E. White, and F. W. Bazer. 1983. Influence of
heat stress on semen quality and respiratory rates of boars in Florida
and Oklahoma. Univ. of Florida, Live Oak ARC Res. Rep. SW-1982-83.







-32-


TABLE 1. EFFECT OF PARITY ON SOW PRODUCTIVITYa


Parityb
Item 1 2 3 4


Number born/litter 9.47c 9.90c 11.10d 11.53d
Number weaned/litter 8.93 8.97 9.31 9.69
Survival, % 93.31 92.98 87.14d 85.27d
Birth weight, kg/litter 12.54 13.18c 13.95 14.80
14 day weight, kg, litter 32.70 32.29 34.57 32.79
Weaning weight, kg/litter 44.81 44.54 46.75 45.11

aLeast squares means.

bSows having 4 or more litters were grouped into parity 4.
cdeMeans in the same row with different superscripts are different
(P<.05).






TABLE 2. EFFECT OF SEASON OF FARROWING ON SOW PRODUCTIVITYa

Season
Item 1 2 3 4 5


Number born/litter 9.78c 11.31d 10.51d 11.04d 10.35d
Number weaned/ d d cd
litter 8.46 10.17 8.57 9.56d 9.12 '
Survival, % 92.31c 89.72c,d 82.27d 86.52d 88.23
Birth Weight, d,e
kg/litter 12.48 13.84 13.49 14.74 14.08
14 day weight,
kg/litter 33.14'e 35.74'd 29.49 34.64cd 34.03
Weaning weight, d e d c,
kg/litter 45.35c 48.94 39.54 46.20c' 46.86cd


aLeast square means.
Seasons were defined as 1. December-February; 2. March-April; 3. May-June;
4. July-September; 5. October-November.
c,d,eMeans in the same row with different superscripts are different
(P<.05).







-32-


TABLE 1. EFFECT OF PARITY ON SOW PRODUCTIVITYa


Parityb
Item 1 2 3 4


Number born/litter 9.47c 9.90c 11.10d 11.53d
Number weaned/litter 8.93 8.97 9.31 9.69
Survival, % 93.31 92.98 87.14d 85.27d
Birth weight, kg/litter 12.54 13.18c 13.95 14.80
14 day weight, kg, litter 32.70 32.29 34.57 32.79
Weaning weight, kg/litter 44.81 44.54 46.75 45.11

aLeast squares means.

bSows having 4 or more litters were grouped into parity 4.
cdeMeans in the same row with different superscripts are different
(P<.05).






TABLE 2. EFFECT OF SEASON OF FARROWING ON SOW PRODUCTIVITYa

Season
Item 1 2 3 4 5


Number born/litter 9.78c 11.31d 10.51d 11.04d 10.35d
Number weaned/ d d cd
litter 8.46 10.17 8.57 9.56d 9.12 '
Survival, % 92.31c 89.72c,d 82.27d 86.52d 88.23
Birth Weight, d,e
kg/litter 12.48 13.84 13.49 14.74 14.08
14 day weight,
kg/litter 33.14'e 35.74'd 29.49 34.64cd 34.03
Weaning weight, d e d c,
kg/litter 45.35c 48.94 39.54 46.20c' 46.86cd


aLeast square means.
Seasons were defined as 1. December-February; 2. March-April; 3. May-June;
4. July-September; 5. October-November.
c,d,eMeans in the same row with different superscripts are different
(P<.05).







-33-


TABLE 3. EFFECTS OF SEASON X PARITY ON THE NUMBER OF PIGS BORNa,b


Parityc
Season 1 2 P3 4


1 9.11 7.35e 9.33e 11.39
2 9.00 12.25f 11.28f 12.72
3 9.33 9.85f 12.50 10.38
f f
4 10.52 9.41 12.18 12.06
5 9.41 10.66 10.22 11.13


aLeast squares means.

Significant season x parity interaction (P<.05).

CSows having 4 or more litters were grouped into parity 4.

Seasons were defined as 1. December-February; 2. March-April; 3. May-June;
4. July-September; 5. October-November.
e,f
efMeans in the same column with different superscripts are different
(P<.05).




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