Table 5.

Effect of dietary Lys concentrations on end of growing (day 56) physiological free essential amino acid profile and urea N in plasma of beef steers

	Treatment				P-value
	CON†	POS‡	RPL||	SEM$	Trt
Plasma urea N, mg/dL	9.8ab	11.0a	8.5b	0.53	0.01
Essential AA, µg/mL
Arginine	16.0b	19.1a	16.1b	0.70	0.01
Histidine	10.8	11.4	11.5	0.48	0.51
Isoleucine	14.2b	16.8a	13.4b	0.70	0.01
Leucine	27.6	27.6	26.1	1.51	0.66
Lysine	14.4b	17.9a	15.4b	0.86	0.02
Methionine	4.0	4.1	4.1	0.17	0.87
Phenylalanine	9.8	10.1	10.1	0.32	0.80
Threonine	7.9z	9.9y	9.0yz	0.57	0.06
Tryptophan	7.9	8.6	8.7	0.49	0.44
Valine	32.7yz	37.6y	31.9z	2.06	0.09

^†CON—diet formulated to be deficient in Lys.

^‡POS—diet formulated to meet Lys requirements through feedstuffs.

^||RPL—diet formulated to meet Lys requirements through AjiPro-L (Ajinomoto Animal Nutrition North America, Eddyville, IA).

^$Standard error of the mean.

^a,bMeans with different superscripts in the same row differ (P ≤ 0.05).

^y,zMeans with different superscripts in the same row tend to differ (0.05 < P ≤ 0.10).