Improving the efficiency of feed utilization in poultry by selection. 2. Genetic parameters of excretion traits and correlations with anatomy of the gastro-intestinal tract and digestive efficiency

Table 3 Genetic correlations (± standard errors) between excretion traits and performance

Trait¹	CDUDM	FEW/BW	DEW/BW	FEW/FI	WE	NE/NI	PE/PI	NE/PE
BW23	0.16 ± 0.06	-0.16 ± 0.21	-0.20 ± 0.15	0.44 ± 0.16	0.86 ± 0.10	-0.19 ± 0.12	0.03 ± 0.19	-0.52 ± 0.18
WG	0.21 ± ne	-0.28 ± ne	-0.29 ± ne	0.02 ± ne	0.24 ± 0.22	-0.37 ± ne	-0.42 ± 0.15	-0.16 ± ne
FI	-0.75 ± ne	0.58 ± ne	0.73 ± ne	0.41 ± ne	-0.17 ± 0.18	0.45 ± ne	0.20 ± 0.14	0.34 ± 0.16
FCR	-0.98 ± 0.01	0.99 ± 0.03	0.92 ± 0.05	0.76 ± ne²	-0.27 ± ne	0.95 ± ne	0.66 ± 0.11	0.88 ± ne
AMEn	0.99 ± 0.00	-0.97 ± 0.04	-0.92 ± 0.03	-0.66 ± 0.07	0.46 ± 0.15	-0.99 ± 0.01	-0.64 ± 0.07	-0.84 ± 0.08
RFI	-0.64 ± ne	0.91 ± ne	0.88 ± ne	0.38 ± 0.15	-0.15 ± ne	0.37 ± 0.09	0.08 ± 0.14	0.30 ± ne

¹ BW23, body weight at 23 d; WG, weight gain between 17 and 23 d; FI, feed intake between 17 and 23 d; FCR; feed conversion ratio; AMEn, apparent metabolisable energy corrected for zero nitrogen balance; RFI, residual feed intake; CDUDM, coefficient of digestive use of dry matter; FEW/BW and DEW/BW, fresh and dry excreta weight relative to body weight at 23 d; FEW/FI, fresh excreta weight relative to feed intake; WE, water content of excreta; NE/NI, PE/PI, ratio of nitrogen and phosphorus excretion to intake; NE/PE, ratio of nitrogen to phosphorus excretion.
² ne: not estimated

ISSN: 2730-6844