K.M. Gourley, H.L. Frobose, M.D. Tokach, J.M. DeRouchey, S.S. Dritz, R.D. Goodband, J.L. Nelssen, and D.L. Davis

Kansas State University, Manhattan

2014 Allen D. Leman Swine Conference

Introduction Mounting consumer pressure to transition away from

individual sow housing in gestation necessitates consideration of alternative lactation and gestation management strategies.

An accompanying sow trial evaluated whether combining boar exposure and reduced suckling pressure can elicit estrus during lactation in sows.

Any modifications of the lactation environment must consider the performance and welfare of the nursing pigs.

Here we report the effects of an altered suckling treatment on the performance of pigs.

Introduction

Two strategies have been used to reduce the suckling stimulus:

1) Split Weaning (SW) - Weaning the heaviest piglets early but allowing light weight littermates to continue to suckle.

2) Litter Separation- Removing the piglets from the sow for a portion of the day (Minimum 8 hrs).

In this trial, a novel presentation combining these strategies was designed to provide an environment to benefit the lightweight pig.

Introduction

Lightweight pigs at weaning have shown a negative effect on pig quality and obtaining full value at market (Fix et al., 2010)

• Reduced daily gain

• Reduced daily feed intake

Lighter weaning weights typically result in more days for pigs to reach market weight.

Objectives

1) To compare the collective growth performance of piglets subjected to an altered suckling regimen (ALT) versus those weaned conventionally.

2) To evaluate the performance of heavyweight piglets split-weaned on d 18 compared to lightweight piglets allowed to suckle until d 25.

3) To compare both of these weight groups to a conventional 21 d lactation.

Procedures

This study incorporated a total of 611 pigs (PIC 327 x 1050;

3.22 lb at birth) originating from 54 sows over 2 farrowing

groups.

Within each farrowing group, the day on which most litters

were born was considered d 0 of lactation.

On d 18, sows were allotted to 1 of 2 treatments based on

parity, suckled litter size and date farrowed.

1) Control

2) Altered Suckling Regimen (ALT)

Procedures On d 18, ALT sows were placed in adjacent pairs.

All but the 5 lightweight pigs/litter were weaned and moved to the nursery on d 18.

Lightweight pigs were combined to form a new litter of 10 pigs and were rotationally suckled (RS) between paired sows by temporarily lifting the divider at 12 h intervals.

All procedures were approved by KSU Institutional Animal Care and Use Committee.

Altered Suckling Treatment

Heaviest pigs weaned on d 18

Lightweight pigs combined

AA B

B

Piglets alternated between sows until d 25

Procedures At weaning, pigs were randomly allotted to nursery pens (7 pigs/pen)

within weaning age.

1) Split-Weaned: Weaned on d 18

2) Control: Weaned on d 21

• Heavy and lightweight control pigs housed together in the nursery.

3) Rotationally-suckled: Weaned on d 25

Each nursery pen contained a 4-hole dry self feeder and nipple

waterer. Feed and water were available ad libitum.

All pigs were fed the same diet consisting of 4 lb/pig of phase 1,

followed by phase 2 until the end of the experiment.

Pigs were weighed individually at birth and on d 18, 21.5, 25, 28.5,

and 32.

Procedures

All experimental data were analyzed using the MIXED procedure of SAS (SAS Institute, Cary, NC).

Pig was the experimental unit, and both nursery pen and farrowing group were random effects.

Least squares means were calculated for each independent variable, and treatments were separated using preplanned contrast statements.

Significance was set at P < 0.05 and tendencies set at P < 0.10.

12.2

14.0

15.3

17.2

19.4

12.3

13.5

15.6

17.1

19.6

9.0

11.0

13.0

15.0

17.0

19.0

21.0

18 21.5 25 28.5 32

Pig

bo

dy

we

igh

t, lb

Day

ALT

Control

Gain: d 18 to d 32

a

b

a,b Means without a common superscript differ P < 0.05

ALT vs. Control, P > 0.67SEM = 0.33

Effects of altered suckling on piglet growth

a,b Means without a common superscript differ P < 0.05

Trt × Wt, P < 0.01SEM = 0.33

13.8

15.7

17.1

19.1

21.5

13.9

14.4

16.8

18.4

20.9

10.7

12.6

14.4

15.8

18.2

10.6

12.2

13.5

15.2

17.3

8.0

10.0

12.0

14.0

16.0

18.0

20.0

22.0

24.0

18 21.5 25 28.5 32

Pig

bo

dy

we

igh

t, lb

Day

Control Heavy

Split-weaned

RotationallySuckledControl Light

b

cc

c b

b

b

b

b

b

a

aa

aa

a

a

b

aa

5.72

6.91

7.63

8.16

6.716.97

7.407.57

5.0

6.0

7.0

8.0

9.0

10.0

<10 lb 10-12 lb 12-14 lb >14 lb

Control

ALT

16%

a

Weight gain from d 18 to 32

20% 16%

24%

28% 32%22% 24% 34%

< 4.5 kg: P < 0.001>6.4 kg: P < 0.01SEM = 0.30

a

b

b

a,b Means without a common superscript differ P < 0.05

Bo

dy

we

igh

t ga

in ,

lb

Weight variation from d 18 to d 32

17.9 17.9

16.4 16.2 16.0

17.2

13.914.6

13.9

13.0

10

12

14

16

18

20

18 21.5 25 28.5 32

Co

effi

cie

nt

of

Var

iati

on

fo

r lit

ter

we

igh

t

Day

Control ALTb

a,b Means without a common superscript differ P < 0.05

a

b

a

Summary

While there was no difference in overall BW between ALT and Controls, SW pigs experienced a more marked post weaning growth check, resulting in 15% lower total gain compared to heavyweight controls.

Conversely, RS pigs experienced a 15% growth benefit compared to lightweight controls.

Summary

Altered suckling as a component of stimulating lactational estrus did not significantly affect overall pig performance during late lactation and the early nursery period.

Variation in pig weight was reduced in ALT pigs as RS pigs were heavier than lightweight controls due to extended lactation.

Implications

Additional research is needed to determine whether the reduction in litter weight variation is sustained to market and its economic implications.

As additional lactational estrus strategies are evaluated, their effects on piglet performance must also be considered.

Thank you!

K-STATERESEARCH

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