Table 6.

Effect of animal species and feedlot period on excretion of urinary purine derivatives, creatinine, urea, and nitrogen compounds measured from total 24-h urine collections

Item	Species		Days in feedlot			SEM	P value1
	Goat	Sheep	28	56	84		Species	DF	S × DF
Purine derivatives2 (mmol/dia)
Allantoin, mmol/d	5.83	9.22	7.83	7.15	7.59	0.98	0.01	0.90	0.74
Acid uric, mmol/d	0.39	1.49	1.19	0.69	0.93	0.15	<0.01	0.15	0.35
Xant. and hipoxant, mmol/d3	0.44	0.85	0.53	0.56	0.85	0.05	<0.01	<0.01	0.94
Total PD, mmol/d4	6.67	11.58	9.55	8.40	9.40	1.05	<0.01	0.74	0.82
Total PD, mmol/kg BW	0.23	0.34	0.34	0.26	0.24	0.03	0.01	0.14	0.77
Total PD, mmol/ kg BW0.75	0.54	0.83	0.81	0.63	0.60	0.07	<0.01	0.15	0.87
Creatinine5
mg/d	558.2	691.8	515.3	625.0	734.6	32.90	<0.01	<0.01	0.70
mg/kg BW	19.20	20.40	19.60	20.30	19.40	2.50	0.34	0.81	0.97
mmol/kg BW0.75	0.39	0.43	0.39	0.42	0.42	6.45	0.17	0.53	0.96
Urea
g/d	4.20	6.04	5.05	4.91	5.41	0.88	0.04	0.87	0.89
mg/kg BW	166.8	181.3	209.6	162.9	149.6	27.30	0.53	0.12	0.41
mg/kg BW0.75	375.4	427.4	466.3	379.1	358.7	64.80	0.35	0.25	0.37
Total nitrogen compounds6
g/d	5.23	7.28	4.20	6.85	7.72	0.62	<0.01	<0.01	0.30
mg/kg BW	185.4	215.4	159.7	221.5	219.9	16.34	0.22	<0.01	0.61
mg/kg BW0.75	425.3	517.7	360.64	521.9	532.2	38.95	0.10	<0.01	0.52

¹DF = days in feedlot; S × DF = interaction between animal species and days in feedlot.

²Xanthine and hipoxanthine: linear effect: P < 0.01 and quadratic effect: P = 0.08.

³Xant. and Hipoxant = xanthine and hipoxanthine.

⁴PD = purine derivatives.

⁵Creatinine (mg/d): linear effect: P < 0.01 and quadratic effect: P = 0.99.

⁶Total nitrogen compounds (g/d): linear effect: P < 0.01 and quadratic effect: P = 0.73; total nitrogen compounds (mg/kg BW): linear effect: P < 0.01 and quadratic effect: P = 0.32; total nitrogen compounds (mg/kg BW^0.75): linear effect: P < 0.01 and quadratic effect: P = 0.38.