. 2020 Sep 12;99(12):7178–7191. doi: 10.1016/j.psj.2020.08.077

Table 2.

Growth performance of broiler chickens fed diets with different amino acid (AA) densities under different stocking densities from 0 to 49 d of age¹.

AA density²	Stocking³ density	Day 0–15			Day 16–30			Day 31–49			Day 0–49
AA density²	Stocking³ density	BWG g/bird	FI g/bird	G:F g/kg	BWG g/bird	FI g/bird	G:F g/kg	BWG g/bird	FI g/bird	G:F g/kg	BWG g/bird	FI g/bird	G:F g/kg
Norm	High	339	680	501	948	1,500	633	1,560^a,b	2,948^a,b	528	2,847	5,127	555
Norm	Low	354	654	546	975	1,507	648	1,678^a	3,062^a	548	3,007	5,213	577
10%Low	High	327	678	499	875	1,451	603	1,518^a,b	2,944^a,b	516	2,720	5,064	537
10%Low	Low	302	684	455	877	1,425	616	1,552^a,b	2,973^a,b	522	2,731	5,066	539
20%Low	High	323	584	564	804	1,433	561	1,404^b,c	2,898^a,b	484	2,531	4,915	515
20%Low	Low	315	587	546	780	1,391	561	1,316^c	2,752^b	478	2,410	4,729	510
SEM		13.1	40.2	37.3	20.2	31.9	7.6	39.6	51.5	7.7	58.7	76.4	7.9
AA density
Norm		346^a	667	524	962^a	1,503^a	640^a	1,619^a	3,005^a	538^a	2,927^a	5,170^a	566^a
10%Low		315^b	681	477	876^b	1,438^a,b	609^b	1,534^a	2,959^a	519^b	2,726^b	5,065^a	538^b
20%Low		319^b	585	555	792^c	1,412^b	561^c	1,360^b	2,825^b	481^c	2,471^c	4,822^b	512^c
SEM		9.3	28.4	26.4	14.3	22.6	5.4	28.0	36.4	5.4	41.5	54.0	5.6
Stocking density
High		330	647	522	876	1,461	599	1,494	2,930	509	2,699	5,036	536
Low		324	641	516	877	1,441	608	1,515	2,929	516	2,716	5,003	542
SEM		7.6	23.2	21.6	11.7	18.4	4.4	22.8	29.8	4.4	33.9	44.1	4.6
P values
AA density		0.046	0.051	0.127	<0.001	0.022	<0.001	<0.001	0.004	<0.001	<0.001	<0.001	<0.001
Stocking density		0.567	0.862	0.856	0.918	0.441	0.158	0.515	0.980	0.292	0.728	0.604	0.325
AA density × stocking density		0.325	0.906	0.482	0.456	0.734	0.555	0.045	0.050	0.247	0.072	0.209	0.221
AA density linear		0.045	0.052	0.405	<0.001	0.007	<0.001	<0.001	0.002	<0.001	<0.001	<0.001	<0.001
AA density quadratic		0.129	0.127	0.064	0.966	0.488	0.192	0.197	0.336	0.177	0.603	0.306	0.893

^a-cMeans with different superscripts within a trait in a column differ significantly (P ≤ 0.05).

Means represent 6 replicates with 8 birds per replicate for each treatment.

Norm = recommended amino acid (AA) density; 10%low = 10% lower than norm AA density; 20%low = 20% lower than norm AA density.

High = 35 kg of body weight/m²; low = 26 kg of body weight/m² of stocking density.