. 2019 Sep 30;9(10):750. doi: 10.3390/ani9100750

Table 4.

Effects of deleting Lysine, Methionine, and Threonine levels in corn–soybean based TMRs on nitrogen metabolism of heifers aged seven to nine months old (n = 16).

Items ¹	Treatments ²				SEM	p Value
Items ¹	PD–Lys	PD–Met	PD–Thr	PC	SEM	p Value
Intake N, g·(kg⁻¹ BW^0.75) d⁻¹	2.92	2.97	2.90	2.87	0.020	0.2961
Fecal N, g·(kg⁻¹ BW^0.75)·d⁻¹	0.90	0.82	0.80	0.79	0.015	0.1223
Urine N, g·(kg⁻¹ BW^0.75)·d⁻¹	1.06 ^b	1.16 ^a	1.02 ^b	0.88 ^c	0.033	0.0011
Total excrete N, g·(kg⁻¹ BW^0.75)·d⁻¹	1.96 ^b	1.98 ^a	1.82 ^ab	1.67 ^ab	0.032	0.0208
N retention, g·(kg⁻¹ BW^0.75)·d⁻¹	0.96 ^b	0.99 ^b	1.08 ^ab	1.20 ^a	0.034	0.0324
Digestible N, g·(kg⁻¹ BW^0.75)·d⁻¹	2.02	2.15	2.06	2.08	0.020	0.2908
N utilization, %	33.08 ^b	33.26 ^b	34.96 ^b	41.77 ^a	1.210	0.0048
N digestibility, %	69.50	72.38	70.79	72.6	0.512	0.0798

¹ N = nitrogen; Total excrete N=Fecal N + Urine N, Absorbed N =Intake – Total excrete N, NR (N retention) = N intake – fecal N – urinary N, N utilization = (N intake – fecal N excretion)/N intake × 100%, N digestibility = (N intake – fecal N excretion)/N intake × 100%; ² treatments: PC = theoretical amino acid balance TMR; PD–Lys = 30% Lys deleted TMR; PD–Met = 30% Met deleted TMR; PD–Thr = 30% Thr deleted TMR; ^{a, b, c} values within the same row with different superscripts differ (p < 0.05).