Light pig syndrome: what causes it and how can it be overcome?
Sadie Douglas
Prof Ilias Kyriazakis and Prof Sandra Edwards
What are light pigs?
 Grow markedly slower than their contemporaries which can lead to variation within a group, this can occur at any stage of production
 Cause difficulties with management and can result in system inefficiencies
 Currently the industry attempts to deal with this problem by remixing pigs based on live weight or removing them from the system as there are no clear recommendations for treatment
Objectives
To develop treatments for light pigs which will decrease the deficit in their growth
Identify the risk factors which contribute towards light pigs and determine whether they can benefit from remedial measures
Develop treatments which would be appropriate for light pigs at different stages of growth
Communicate findings with relevant stakeholders
What have we learnt so far?
1. Data analysis showed that growth performance to slaughter was not solely reliant on birth weight, with weaning weight also playing a critical role
2. Additionally it was found that piglets with low birth weight (LBiW) are capable of some degree of compensatory growth but interventions must be early in production to achieve this
3. LBiW pigs did not benefit from a diet higher in amino acids: energy fed at 9 weeks of age (growers). Was this nutritional intervention too late?
Can nutritional treatments applied earlier on improve the growth performance of LBiW pigs??
Management strategies to improve the performance of low birth weight pigs to weaning and their long term consequences
Aim
To determine the effect of littermate weight and milk supplementation during lactation on the growth performance of LBiW pigs to slaughter weight Design
 2 x 2 factorial design
 Littermate weight (L= LBiW only (≤ 1.20 kg), MX= LBiW and NBiW (1.6 to 2.0 kg)
 Milk supplementation (S= supplement or N= no supplement)
The effect of birth weight and milk supplementation on the performance of LBiW pigs in L litters (LBiW only) or MX litters (litters with both LBiW and NBiW) from d 1 to 28
Treatment
Day
P‐ value
LS
L N
MX S
MX N
Littermate Milk
weight
Littermat
e x Milk
1
1.11
1.14
1.13
1.15
0.595
0.285
0.697
14
3.84
3.78
3.64
3.89
0.752
0.544
0.308
28
7.54
7.13
6.73
6.87
0.049
0.596
0.292
1 to 14
0.210 0.203
0.193
0.210
0.680
0.633
0.261
14 to 28
0.264 0.239
0.221
0.213
0.027
0.270
0.558
BW, kg
ADG, kg/d
Conclusions
 Birth to weaning ADG can be increased by cross fostering LBiW piglets into litters with similar weight littermates
 Provision of supplementary milk does not benefit LBiW piglet performance, but it does reduce the BW variation in mixed litters
 Whilst the advantages of the treatments applied during the lactation period are still present at slaughter, they are no longer significant
The effect of post weaning feeding regimes on the performance of low birth weight pigs to 10 weeks of age
Aim; Investigate the effects on nursery performance of a starter regime which is specifically formulated for LBiW pigs in comparison to a standard commercial starter regime which is formulated for the ‘average pig’
Trt 1
Trt 2
Trt 3
Trt 4
Trt 6
Trt 5
BiW
(L or N)
L
L
L
L
N
N
Starter Regime (A or B)
2Y
3Z
(A)
2.5 X
2Y
3Z
(B)
2 Y
3 Z
(A)
2.5 X
2 Y
3 Z
(B)
2Y
3Z
(A)
2.5 X
2 Y
3 Z
(B)
Additional feed
(Y or N)
(N)
(N)
2.5 Z
(Y)
2.5 Z
(Y)
(N)
(N)
The effect of birth weight, starter regime and additional feed on the mean BW of pigs at d 70
Body weight, kg
35.0
30.0
26.9
27.7
L (A N)
L (A Y)
30.0
28.9
30.9
30.3
L (B Y)
L ( B N)
N (A N)
N (B N)
25.0
20.0
15.0
10.0
5.0
0.0
Treatment
Conclusions
 Feeding LBiW pigs a starter regime which is tailored to their reduced body weight at weaning (regime B) improves performance to d 70 (with or without additional feed)
 Pigs given access to regime B with additional feed (Y) weighed the same as NBiW pigs by d 70 (over 30 kg)
 Feeding LBiW pigs an improved regime is more cost effective than feeding them a standard commercial regime. It pays to feed LBiW pigs better!
What have we learnt?
1. Early intervention is critical. Nutritional treatments at different stages of production (lactation, weaner, grower) can affect the outcomes
2. Selective cross fostering of LBiW pigs can improve preweaning performance
3. Specialised diets fed at weaning can improve performance to the end of the nursery phase
4. Any additional weight gained as a result of treatments is likely to be retained at slaughter
Acknowledgements
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BPEX
Dr Ian Wellock and Primary diets
ACMC and Genus
Cockle Park staff; Darren Blomfield and Mark Brett