Table 5.

Mean, standard error of the mean (SEM), and phenotypic correlation for breast muscle quality of small-sized meat ducks classified as low-, medium-, and high-residual feed intake (RFI) or low-, medium-, and high-residual intake and gain (RIG).

Trait1	RFI					RIG					Correlation coefficients
	Low	Medium	High	SEM	P value	Low	Medium	High	SEM	P value	RFI	RIG
pH1	6.11	6.11	6.05	0.021	0.057	6.05b	6.13a	6.12a	0.023	0.021	−0.240*		0.270*
pH24	6.14	6.11	6.08	0.025	0.219	6.08	6.14	6.13	0.027	0.176	−0.199		0.231
L*	40.42	40.08	39.70	0.393	0.422	39.55	40.26	40.36	0.409	0.288	−0.140		0.106
a*	14.91	14.70	14.16	0.361	0.328	14.17	14.81	15.01	0.408	0.302	−0.162		0.135
b*	5.71	5.45	5.26	0.220	0.359	5.23	5.60	5.65	0.254	0.416	−0.150		0.156
Shear force	25.14	24.34	25.44	1.381	0.851	25.97	23.55	25.22	1.479	0.529	0.052		0.130
Drip loss (%)	23.92	25.74	24.90	1.343	0.635	24.98	25.29	24.16	1.493	0.859	0.058		0.017
Cook loss (%)	29.56	29.72	29.00	0.941	0.855	29.13	29.72	29.53	0.948	0.906	−0.048		0.191
Moisture (%)	74.10	74.28	74.10	0.103	0.398	74.02	74.24	74.10	0.120	0.470	−0.007		0.033
Protein (%)	23.66	23.44	23.51	0.106	0.342	23.53	23.35	23.64	0.113	0.268	−0.101		0.032
Intramuscular fat (%)	2.41	2.47	2.62	0.076	0.126	2.64	2.50	2.41	0.084	0.120	0.218		−0.147
Collagen (%)	0.37	0.34	0.40	0.043	0.641	0.40	0.31	0.38	0.048	0.416	0.042		−0.026

^aDifferent letters within a row and of the RFI or RIG classification indicate significant differences (P < 0.05).

^bDifferent letters within a row and of the RFI or RIG classification indicate significant differences (P < 0.05).

^⁎Indicates a significant correlation (P < 0.05).

¹pH₁ = pH value measured 1 h after slaughter; pH₂₄ = pH value measured 24 h after slaughter; L* = lightness; a* = redness of red; b* = yellowness.