Evaluation of Protein Concentration and Limiting Amino Acids Including Lysine and Met + Cys in Prestarter Diet on Performance of Broilers

Table 3

Effect of feeding diets containing various levels of crude protein (CP) and lysine (Lys) on body weight gain, feed intake, and feed conversion ratio of broiler chicks (Experiment 1-1).

Treatments			BWG (gr)		FI (gr)		FCR (gr/gr)
Number	CP (%)	Lys (%)	1–7 d	1–10 d	1–7 d	1–10 d	1–7 d	1–10 d
1	23.2	1.5	223.7^a	351.1^a	190.3^a	349.9	0.851	0.997
2	23.2	1.4	215.7^ab	338.9^abc	185.9^ab	343.8	0.862	1.014
3	23.2	1.3	215.6^ab	341.5^ab	190.7^a	350.1	0.885	1.025
4	23.2	1.2	205.7^bc	324.9^cd	180.0^b	340.4	0.875	1.032
5	21	1.5	210.7^bc	329.4^bcd	187.2^ab	344.2	0.888	1.045
6	21	1.4	209.1^bc	329.6^bcd	183.7^ab	343.0	0.879	1.041
7	21	1.3	207.6^bc	327.0^bcd	184.9^ab	339.7	0.891	1.039
8	21	1.2	204.1^c	316.4^d	178.9^b	333.2	0.877	1.053
Pooled SEM			3.05	4.41	2.39	4.21	0.016	0.015
Probability
Protein × lysine			*	*	*	NS	NS	NS
Protein			*	*	NS	NS	NS	*
Lysine			*	*	*	NS	NS	NS

^a–dMeans in each column without common superscripts are significantly different.
*Data are means of four replicates having 20 birds in each. BWG: body weight gain, FI: feed intake, FCR: feed conversion ratio, CP: crude protein, Lys: lysine, SEM: standard error of mean, NS: not statistically significant; *𝑃<0.05.