Table 1.

Nested ANOVA, observational components of variance, and heritability estimates for daughters' pronotum width, brood mass weight, and brood mass number in O. taurus

Source	df	MS	F ratio	Variance	% of total	Sib	Parent-offspring
						h2 ± SE	h2 ± SE
Pronotum width
Sire	19	0.14629	1.24	1.565  × 10−4	0.20	0.008  ± 0.070	−0.020  ± 0.069
Dam[Sire]	154	0.13015	2.09**	1.750  × 10−2	21.91	0.876  ± 0.195	0.279  ± 0.186†
Progeny	522	0.06221		6.221  × 10−2	77.89
Total	695	0.07987		7.987  × 10−2	100.00
Brood mass weight
Sire	19	0.11693	2.10**	1.632  × 10−3	3.36	0.134  ± 0.091
Dam[Sire]	154	0.05854	1.37**	4.034  × 10−3	8.31	0.332  ± 0.165	0.219  ± 0.111*
Progeny	522	0.04288		4.288  × 10−2	88.33
Total	695	0.04863		4.854  × 10−2	100.00
Brood mass number
Sire	19	46.8207	0.69	−0.872	−1.65	−0.066  ± 0.037
Dam[Sire]	154	72.6513	1.54**	6.541	12.36	0.494  ± 0.044	0.014  ± 0.165
Progeny	522	47.2514		47.251	89.29
Total	695	53.6843		52.921	100.00

To account for unequal sample sizes of offspring per sire, the error term for sires was calculated by using Satterthwaite's approximation: 0.8238 MS(Dam[Sire]) + 0.1762 MS(Error). Hypothesis testing of sib heritabilities based on MS_S/MS_D[S], as recommended by Lynch and Walsh (50). The parent-offspring heritability caused by sires were calculated from linear regression by using midoffspring values calculated across the dams of each sire (df = 19). The parent-offspring heritability caused by dams was calculated by intrasire regression (48). Significance testing was based on Student's t. 

^**, P < 0.0001; 

^**, P < 0.01; 

^*, P < 0.05;  

^†, P = 0.075.