The Effect of Parity and Stage of Gestation on Whole Body and Maternal Growth and Feed Efficiency of Gestating Sows - Lori Thomas, from the 2017 Allen D. Leman Swine Conference, September 16-19, 2017, St. Paul, Minnesota, USA. More presentations at http://www.swinecast.com/2017-leman-swine-conference-material

1. The Effect of Parity and Stage of Gestation
on Whole Body and Maternal Growth and
Feed Efficiency of Gestating Sows
L.L. Thomas, S.S. Dritz, M.D. Tokach, R.D. Goodband, J.C.
Woodworth, and J.M. DeRouchey
Kansas State University, Manhattan

2. Introduction
• Feed intake in gestation is typically based on the sow’s body
condition (or BW), parity, and stage of gestation.
• Models have been developed based on these criteria to
determine gestating sow nutrients requirements.
• These factors have been studied through the years but
research conducted in commercial environments is limited and
the application of these models in commercial environments is
also limited.
• Current research specifically pertaining to whole body and
maternal growth and feed efficiency of sows raising > 13 pigs
per litter is also lacking.

3. Objective
• Our objective was to determine the effect of parity
and stage of gestation on whole body and maternal
growth and feed efficiency of sows housed in a
commercial farm and fed via electronic sow feeders
(ESF).

4. Materials and Methods
• A total of 712 females (Line 1050, PIC, Hendersonville, TN; 249
gilts and 463 sows) from a commercial sow farm were used in
this study.
• Females were group-housed and individually fed with
electronic sow feeders.
–3 pens, approximately 260 females per pen
–6 electronic feeding stations per pen (45 females per
station)
–Females were group-housed in dynamic groups from d 5 to
112 of gestation
–Each pen was equipped with a scale located in the alleyway
following the feeding station, returning to the pen

5. Entrance to ESF

6. Individual
Feeding Station
Sow
Separation
Pen
Scale

7. Materials and Methods
• Feed intake and BW were recorded daily throughout gestation.
• Females were enrolled in the study on day 5 of gestation and
at day 112 of gestation, they were moved to the farrowing
house.
– Backfat (P2) was obtained on day 5 and day 112 of gestation
• Females were fed a common diet with 0.63% SID Lys according
to parity and body condition:
– Gilts: 2.0 kg per day (6,450 kcal ME/d)
– Ideal sows: 2.3 kg per day (7,289 kcal ME/d)
– Skinny sows: 3.0 kg per day (9,675 kcal ME/d)
• The study was conducted over a 149-d period beginning in
early May and concluding mid-October, 2015.

8. Materials and Methods
• ADFI, BW, ADG, G:F were generated daily for each sow.
• Energy requirements were predicted using a series of
equations to model nutrient utilization in gestation.
• Energy requirements were divided into tissue pools for
maintenance, maternal growth (maternal protein and fat
deposition) and products of conceptus.
• Data was divided into 3 parity groups: 1 (gilt), 2 and 3+
• Gestation was divided into 3 periods: d 5 to 39, 40 to 74,
and 75 to 109.

9. Materials and Methods
• Growth and estimated response variables were analyzed using
the GLIMMIX procedure of SAS whereby the linear predictor
included parity group, period of gestation and all interactions
as fixed effects, as well as the random effects of period nested
within individual sow.
• Backfat and reproductive performance were analyzed similarly
whereby the linear predictor included parity group as the fixed
effect and the individual sow as the random effect.
• Degrees of freedom were estimated using the Kenward-Rogers
approach and pairwise comparisons were conducted on such
means using Tukey or Bonferroni adjustments.
• Results were considered significant at P ≤ 0.05 and marginally
significant at 0.05 < P ≤ 0.10

10. Composition of diet, as-fed
Ingredient, %
Corn 54.75
Soybean meal 11.85
DDGS, 8.5% oil 30.00
Monocalcium phosphate 0.65
Limestone 1.65
Salt 0.50
Liquid Lys, 50% 0.15
Choline chloride 60% 0.11
Vitamin & trace mineral premix 0.38
Total 100.0
Calculated analysis
SID lysine, % 0.63
Total lysine, % 0.79
SID amino acid ratios
Ile:lys 93
Leu:lys 258
Met & Cys:lys 88
Thr:lys 82
Trp:lys 23
Val:lys 112
CP, % 18.5
ME, kcal/kg 3,225
SID Lysine:ME, g/Mcal 1.95
Ca, % 0.83
P, % 0.59
Available P, % 0.47

11. Descriptive Statistics
Mean Median SD Minimum Maximum
Initial backfat, mm 16.1 16.0 3.69 8 26
Final backfat, mm 16.6 17.0 3.18 7 28
Total intake, kg 228.5 237.0 17.61 181 310
Initial BW, kg 165.0 163.0 22.99 107 234
Final BW, kg 221.8 219.9 21.01 163 294
BW gain, kg 56.8 58.5 14.35 8 116

12. Descriptive Statistics
Mean Median SD Minimum Maximum
Parity 2.3 2.0 1.31 1 5
Total born 14.9 15.0 3.13 1 25
Born alive 14.2 14.5 3.06 1 23
Stillbirths 0.37 0.00 0.68 0 9
Mummies 0.30 0.00 0.59 0 4
Pigs weaned 13.34 14.0 2.19 0 17
Gestation Length, d 115.3 115.0 0.99 112 117

13. ADFI, kg
d 5 to 39 d 40 to 74 d 75 to 109
Parity 1 1.95x ± 0.006 1.96x ± 0.006 1.97x ± 0.006
Parity 2 2.24z ± 0.006 2.25y ± 0.006 2.25y ± 0.006
Parity 3+ 2.22ay ± 0.005 2.27by ± 0.005 2.27by ± 0.005
Stage of gestation × parity group = P < 0.001
1.80
1.90
2.00
2.10
2.20
2.30
0 10 20 30 40 50 60 70 80 90 100 110
ADFI,kg
Gestation, d
Parity 1 Parity 2 Parity 3+
Rowabc P <0.05
Columnxyz P <0.05

14. Feed intake throughout the course of
gestation, Parity 1
26, 560 observations

15. Feed intake throughout the course of
gestation, Parity 2
20, 051 observations

16. Feed intake throughout the course of
gestation, Parity 3+
29, 349 observations

17. BW, kg
d 5 to 39 d 40 to 74 d 75 to 109
Parity 1 155.9ax ± 0.95 177.7bx ± 0.95 202.4cx ± 0.95
Parity 2 165.9ay ± 1.09 181.3by ± 1.09 198.7cy ± 1.09
Parity 3+ 190.4az ± 0.90 205.4az ± 0.90 223.6bz ± 0.90
Stage of gestation × parity group = P < 0.001
140
160
180
200
220
240
0 10 20 30 40 50 60 70 80 90 100
BW,kg
Gestation, d
Parity 1 Parity 2 Parity 3+
Rowabc P <0.05
Columnxyz P <0.05

18. ADG, kg
d 5 to 39 d 40 to 74 d 75 to 109
Parity 1 0.53ay ± 0.011 0.75bx ± 0.011 0.65cx ± 0.011
Parity 2 0.39ax ± 0.013 0.56by ± 0.013 0.40ay ± 0.013
Parity 3+ 0.30az ± 0.010 0.53by ± 0.010 0.61cx ± 0.010
Stage of gestation × parity group = P < 0.001
0.00
0.20
0.40
0.60
0.80
0 10 20 30 40 50 60 70 80 90 100
ADG,kg
Gestation, d
Parity 1 Parity 2 Parity 3+
Rowabc P <0.05
Columnxyz P <0.05

19. G:F
d 5 to 39 d 40 to 74 d 75 to 109
Parity 1 0.29ay ± 0.005 0.33bz ± 0.005 0.34by ±0.005
Parity 2 0.19ax ± 0.006 0.22bx ± 0.006 0.20ax ± 0.006
Parity 3+ 0.20ax ± 0.005 0.22bx ± 0.005 0.22bx ± 0.005
Stage of gestation × parity group = P < 0.001
0.00
0.10
0.20
0.30
0.40
0 10 20 30 40 50 60 70 80 90 100
G:F
Gestation, d
Parity 1 Parity 2 Parity 3+
Rowabc P <0.05
Columnxyz P <0.05

20. Initial and Final Backfat, mm
18.19a
14.23c
15.36b
18.14x
15.58y 15.87y
10
12
14
16
18
20
Parity 1 Parity 2 Parity 3+
Backfat,mm
Initial, d 5 Final, d 112
abcP <0.05 – Initial backfat
xyP <0.05 – Final backfat

21. Total born, n
14.8bx
14.2by
15.5a
10
11
12
13
14
15
16
17
Parity 1 Parity 2 Parity 3+
Totalborn,n
abP <0.05
xyP <0.10

22. Whole Body Conclusions
• Feed intake is variable throughout the course of gestation,
regardless of parity, with females not necessarily consuming
their full feed allowance.
• Body weight gain was greatest for parity 1 sows followed by
parity 2 and 3+ sows.
• Parity 1 sows had the greatest ADG in comparison to parity
2 and 3+ sows in each period of gestation.

23. Whole Body Conclusions
• Regardless of parity group, G:F was poorest from d 5 to 39
of gestation compared with sequential periods of gestation.
• Parity 1 sow G:F was greater than parity 2 and 3+ sows for
all periods of gestation.
• Parity 2 and 3+ sows gained backfat through gestation but
parity 1 sows maintained backfat.

24. 4000
4500
5000
5500
6000
6500
20 30 40 50 60 70 80 90 100
Gestation, d
Parity 1 Parity 2 Parity 3+
Maintenance Requirement, kcal
d 5 to 39 d 40 to 74 d 75 to 109
Parity 1 4,620ax ± 20.0 5,114bx ± 20.0 5,640cx ± 20.0
Parity 2 4,859ay ± 23.0 5,194by ± 23.0 5,563cy ± 23.0
Parity 3+ 5,387az ± 19.0 5,702bz ± 19.0 6,076cz ± 19.0
Stage of gestation × parity group = P < 0.001
Rowabc P <0.05
Columnxyz P <0.05
Maintenance
requirement,kcal

25. 0
100
200
300
400
20 30 40 50 60 70 80 90 100
Gestation, d
Parity 1 Parity 2 Parity 3+
Energy retention of conceptus, kcal
d 5 to 39 d 40 to 74 d 75 to 109
Parity 1 20.54a ± 2.157 122.90bx± 2.157 328.34cx ±2.157
Parity 2 22.36a ± 2.482 132.40by ± 2.482 352.94cy ± 2.482
Parity 3+ 23.67a ± 2.052 140.99bz ± 2.052 376.80cz ± 2.052
Stage of gestation × parity group = P < 0.001
Rowabc P <0.05
Columnxyz P <0.05
Energyretentionof
conceptus,kcal

26. 150
170
190
210
230
250
270
290
20 30 40 50 60 70 80 90 100
Gestation, d
Parity 1 Parity 2 Parity 3+
Energy used for maternal protein deposition, kcal
d 5 to 39 d 40 to 74 d 75 to 109
Parity 1 275ax ± 1.64 229bx ± 1.64 210cx ±1.64
Parity 2 258ay ± 1.89 211by ± 1.89 190cy ± 1.89
Parity 3+ 228az ± 1.56 186bz ± 1.56 163cz ± 1.56
Stage of gestation × parity group = P < 0.001
Rowabc P <0.05
Columnxyz P <0.05
Energyusedformaternal
proteindeposition,kcal

27. -300
200
700
1200
1700
20 30 40 50 60 70 80 90 100
Gestation, d
Parity 1 Parity 2 Parity 3+
Energy used for maternal lipid deposition, kcal
d 5 to 39 d 40 to 74 d 75 to 109
Parity 1 928ax ± 20.17 463bx ± 20.17 -244cx ± 20.17
Parity 2 1,510ay ± 23.22 1,170by ± 23.22 531cy ± 23.22
Parity 3+ 1,070az ± 19.19 830bz ± 19.19 171cz ± 19.19
Stage of gestation × parity group = P < 0.001
Rowabc P <0.05
Columnxyz P <0.05
Energyusedformaternal
lipiddeposition,kcal

28. Predicted Energy Use – Parity 1

29. Predicted Energy Use – Parity 2

30. Predicted Energy Use – Parity 3+

31. Maternal Body Conclusions
• Sow gestation nutrient requirements are affected largely by
requirements of the sow for maintenance and maternal
protein and lipid deposition, each of which is heavily
influenced by parity and stage of gestation.
• Predictions indicate that parity 1 sows are in a negative energy
balance late in pregnancy.
• These findings would back up current recommendations that
gilts should have their feed allowance increased from day 90 of
gestation through farrowing in order to prevent them from
entering a negative energy balance.

32. Thank you!
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