Genetic analysis of teat number in pigs reveals some developmental pathways independent of vertebra number and several loci which only affect a specific side

Table 1 Descriptive statistics and estimates of variance components for the population of animals (n = 6472) used for statistical model development

Trait	Residual variance	Additive genetic variance	Phenotypic variance	Heritability (SE)	Mean	Range
TTN	0.592	0.578	1.171	0.494 (0.038)	14.73	8 to 21
LTN	0.242	0.149	0.390	0.381 (0.037)	7.32	5 to 13
RTN	0.319	0.137	0.456	0.301 (0.035)	7.41	2 to 12
MAX	0.234	0.154	0.389	0.397 (0.037)	7.59	6 to 13
L − R	0.525	0.000	0.525	0.000 (0.003)	−0.08	−4 to 7
DIF	0.324	0.002	0.326	0.006 (0.005)	0.45	0 to 7

LTN left side teat number, MAX maximum teat number of a side, RTN right side teat number, TTN total teat number, L − R difference between LTN and RTN, and DIF absolute value of L − R

ISSN: 1297-9686