Table 5.

Cluster characteristics of birth weight class 1 piglets (smallest 25% at birth) clustered in different groups based on birth weight and various morphometric characteristics. Data are expressed as LSM ± SED¹

Cluster (%)	1	2	3	SED	P-value
	44.2%	34.6%	21.2%
Cluster characteristics
Body weight, kg
d 0	1.10a	0.835b	1.10a	0.002	< 0.001
Relative BiW2	0.807a	0.610b	0.794a	0.002	< 0.001
Morphometric characteristics
Abdominal circumferences, cm	20.0b	17.9a	19.8b	0.051	< 0.001
Cranial circumferences, cm	20.0b	18.7a	20.0b	0.014	< 0.001
Snout to ear length, cm	9.64a	9.18c	9.47b	0.010	< 0.001
Crown rump length, cm	23.9a	21.5b	21.8b	0.021	< 0.001
Body mass index3, kg/m2	19.5b	18.0c	23.0a	0.032	< 0.001
Ponderal index4, kg/m3	81.4b	83.9b	106a	0.183	< 0.001
Birth weight: Cranial circumferences, kg/cm	0.0549a	0.0458b	0.0546a	0.0001	< 0.001
Snout to ear length: Birth weight, cm/ kg	8.84b	11.3a	8.74b	0.025	< 0.001

^a,b,cValues with different superscripts differ significantly (P < 0.05)

¹Pigs were weighed within 12 h post-partum (d 0)

²Relative birth weight = (Birth weight piglet/ mean birth weight birth litter)

³Body mass index = birth weight (kg)/[crown rump length (m)]²

⁴Ponderal index = birth weight (kg)/[crown rump length (m)]³