Table 2. Variances of each of the components estimated and the resulting genetic parameters. Standard errors are given for each estimate.

				Variance				Maternal Heritability (m2)
Breed	Lactation	Milk Trait	Units	Additive Genetic	Maternal Genetic	Residual	Heritability (h2)
Jersey	1	Volume	Litres	40160**	1457**	90681**	0.301±0.016**	0.011±0.005*
		Fat	Kilograms	68.3**	2.0ns	219.6**	0.237±0.015**	0.007±0.004ns
		Protein	Kilograms	34.0*	1.6ns	110.6ns	0.232±0.015**	0.011±0.005*
	2	Volume	Litres	51912**	1385**	116329**	0.304±0.018**	0.008±0.005ns
		Fat	Kilograms	72.4**	5.5**	291.2**	0.199±0.016**	0.015±0.007*
		Protein	Kilograms	45.2**	2.1ns	143.6*	0.238±0.017**	0.011±0.006ns
Holstein Friesian	1	Volume	Litres	65442**	2276**	142726**	0.316±0.011**	0.011±0.003**
		Fat	Kilograms	79.7**	4.9ns	235.7*	0.250±0.010**	0.015±0.004**
		Protein	Kilograms	42.7ns	1.9ns	141.7ns	0.233±0.010**	0.011±0.003**
	2	Volume	Litres	79014**	3678**	182014**	0.301±0.012**	0.014±0.004**
		Fat	Kilograms	91.3**	4.0ns	308.4**	0.227±0.011**	0.010±0.004*
		Protein	Kilograms	51.9**	2.8ns	176.6ns	0.227±0.011**	0.012±0.004**

**P<0.01;

*P<0.05;

ns = not significantly different from zero.