Genetic and environmental heterogeneity of residual variance of weight traits in Nellore beef cattle

Table 3 Estimates of parameters related to the residual variance of weight traits in Nellore beef cattle

Trait/Sex^*	Model^**	σ² _Av,exp	σ² _m,exp	dAIC	dBIC	σ² _Av	Ev(%)	h²_v(%)	r_mv
GBW/M	HOM	0.0165	0.549	0.19	8.2	372	8.54	0.13	0.23
GBW/M	HOM	(0.02)	(0.09)	0.19	8.2	372	8.54	0.13	0.23
GBW/M	HET	1.07	0.297	−276	−285	21500	65.20	5.87	0.21
GBW/M	HET	(0.19)	(0.11)	−276	−285	21500	65.20	5.87	0.21
GBW/F	HOM	2E-7	0.105	2	10	0.00	0.03	0.00	0.12
GBW/F	HOM	(0.00)	(0.08)	2	10	0.00	0.03	0.00	0.12
GBW/F	HET	0.495	0.0614	−121	−129	7030	43.80	3.37	0.26
GBW/F	HET	(0.10)	(0.09)	−121	−129	7030	43.80	3.37	0.26
GBW/B	HOM	0.0404	0.265	−16	−7.1	730	12.90	0.39	0.27
GBW/B	HOM	(0.02)	(0.04)	−16	−7.1	730	12.90	0.39	0.27
GBW/B	HET	0.476	0.189	−350	−340	8570	43.70	3.89	0.27
GBW/B	HET	(0.07)	(0.05)	−350	−340	8570	43.70	3.89	0.27
YW/M	HOM	2E-7		2	9.1	0.01	0.03	0.00	0.12
YW/M	HOM	(0.00)		2	9.1	0.01	0.03	0.00	0.12
YW/M	HET	1.68		−240	−230	44400	78.70	5.50	−0.01
YW/M	HET	(0.32)		−240	−230	44400	78.70	5.50	−0.01
YW/F	HOM	0.0277		0.83	8.2	881	10.60	0.21	0.21
YW/F	HOM	(0.03)		0.83	8.2	881	10.60	0.21	0.21
YW/F	HET	0.457		−79	−71	14200	42.70	3.02	0.36
YW/F	HET	(0.11)		−79	−71	14200	42.70	3.02	0.36
YW/B	HOM	0.0193		−0.002	8.2	740	8.77	0.13	0.25
YW/B	HOM	(0.02)		−0.002	8.2	740	8.77	0.13	0.25
YW/B	HET	0.473		−195	−187	17300	43.00	2.89	0.23
YW/B	HET	(0.08)		−195	−187	17300	43.00	2.89	0.23

^*GBW = weight gain from birth to weaning; YW = long-yearling weight; M = males; F = females; B = both sexes; ^**HOM = assuming homogeneous residual variance in model (1); HET = model allowing for differences between sire families in residual variance. σ²_Av,exp: estimated additive genetic variance for log squared of estimated residuals, ln(ê²); σ²_m,exp: estimated maternal additive genetic variance for ln(ê²); σ²_Av:estimates of additive genetic variance on the scale of the residual variance (σ²_e), assuming the quantitative model for genetic heterogeneity of σ²_e[5]; Ev: evolvability of σ²_e in %; h²_v: heritability of σ²_e; r_mv: Pearson’s correlation between sire EBV for mean and for σ²_e; AIC = Akaike Information Criterion; BIC = Bayesian Information Criterion; dAIC (dBIC): difference between the AIC (BIC) obtained for a model considering additive genetic effects on ln(ê²) and the AIC (BIC) of a model only with fixed effects; negative values indicate that better fit was obtained with the model considering genetic heterogeneity on ln(ê²); standard errors are presented between brackets.

ISSN: 1297-9686