Table 2.

Nitrogen distribution in different types of yak milk (%) [7,16,22,23].

	Zhongdian Yak	Gannan Yak	Maiwa Yak	Cow	Buffalo	Goat
TN	0.68 ± 0.02	0.84 ± 0.06	0.79 ± 0.04	3.25 ± 0.03	3.87 ± 0.02	2.95 ± 0.02
NPN	0.07 ± 0.11	0.03 ± 0.02	0.04 ± 0.01	0.33 ± 0.03	0.38 ± 0.02	0.39 ± 0.01
NPN/TN	10.29	3.58	5.06	10.15	9.82	13.22
WPN	0.13 ± 0.52	0.17 ± 0.04	0.15 ± 0.01	0.47 ± 0.01	0.68 ± 0.02	0.53 ± 0.02
WPN/TN	19.12	20.23	18.99	14.46	17.57	17.97
CN	0.48 ± 0.17	0.64 ± 0.06	0.60 ± 0.03	2.79 ± 0.02	3.20 ± 0.03	2.44 ± 0.03
CN/TN	70.59	76.19	75.95	85.85	82.69	82.71
WPN/CN	27.08	26.41	25	16.85	21.25	21.72