Table 3.

Effects of different standardized ileal digestible threonine:lysine ratios (Thr:Lys) on growth performance of weaned pigs reared under clean and unclean sanitary conditions.¹

Item	Clean sanitary condition2									Unclean sanitary condition3
	Corrected SID Thr:Lys, %					SEM	P-value4			Corrected SID Thr:Lys, %					SEM	P-value
	61	64	67	69	72		Thr	Lin	Quad	61	64	67	69	72		Thr	Lin	Quad
Initial BW, kg	7.37	7.16	7.33	7.40	7.30	0.39				7.18	7.03	7.05	7.11	7.12	0.33
Final BW, kg	17.5	17.3	17.7	17.6	18.0	0.34	0.598	0.166	0.508	15.7	16.0	15.1	15.7	15.8	0.63	0.896	0.940	0.637
wk 1 (d 0 to 7)
ADG, g	299	320	313	317	354	24.0	0.582	0.171	0.638	209	214	221	234	197	18.5	0.714	0.947	0.283
ADFI, g	449	447	430	444	432	31.4	0.987	0.712	0.922	322	349	303	344	299	26.0	0.558	0.533	0.576
G:F	0.66	0.73	0.73	0.73	0.82	0.04	0.178	0.033	0.835	0.66	0.65	0.73	0.69	0.65	0.05	0.738	0.879	0.343
wk 2 (d 8 to 14)
ADG, g	501	442	459	512	507	27.7	0.317	0.352	0.166	411	415	403	439	381	19.4	0.35	0.555	0.313
ADFI, g	828	749	797	835	808	44.9	0.714	0.750	0.575	580	537	535	599	568	25.3	0.354	0.655	0.358
G:F	0.60	0.59	0.58	0.62	0.62	0.03	0.464	0.487	0.710	0.71	0.78	0.75	0.73	0.67	0.03	0.263	0.247	0.066
wk 3 (d 15 to 21)
ADG, g	665	707	736	664	687	33.4	0.509	0.997	0.265	544	570	574	583	596	26.9	0.731	0.184	0.842
ADFI, g	1,002	980	1,011	981	964	39.9	0.921	0.556	0.732	876	804	774	808	878	31.4	0.102	0.929	0.007
G:F	0.67	0.72	0.73	0.68	0.71	0.03	0.409	0.581	0.283	0.63	0.71	0.75	0.72	0.68	0.04	0.170	0.322	0.024
Overall (d 0 to 21)
ADG, g	487	487	500	499	521	16.9	0.640	0.154	0.651	388	399	400	423	387	15.9	0.508	0.651	0.233
ADFI, g	758	720	741	757	744	28.8	0.899	0.928	0.684	592	564	538	594	571	20.8	0.340	0.870	0.245
G:F	0.64	0.68	0.68	0.67	0.70	0.02	0.407	0.138	0.822	0.66	0.71	0.75	0.72	0.70	0.02	0.071	0.440	0.006

SID = standardized ileal digestible; SEM = standard error of mean.

¹Values are least square means; n = 6 per treatment.

²Clean sanitary condition: piglets were housed in cleaned and disinfected rooms and fed antibiotic-free diets.

³Unclean sanitary conditions: piglets were housed in a room where cleaning and disinfection was not done, moreover, manure from swine herd was added (5 kg per pen) to the pens on d 0 and 7 of the experiment.

⁴Probability values of linear (Lin) and quadratic (Quad) effects for dietary SID Thr:Lys (%).