. 2019 Dec 17;9(12):305. doi: 10.3390/metabo9120305

Table 4.

Average concentrations (μM) of metabolites which showed significant differences between feeding systems for skim milk powder, sweet whey, ideal whey, and acid whey, determined by LC–MS/MS.

Ingredient	Metabolite (μM)	GRS	CLV	TMR
Skim milk powder	Glutamine	4.38 (±0.54) ^a	4.95 (±1.24) ^a	12.4 (±0.28) ^b
	Phosphocreatine	8.05 (±1.70) ^a,b	6.32 (±0.56) ^a	16.3 (±4.45) ^b
	Serine	22.1 (±0.78) ^b	18.3 (±1.20) ^a,b	10.0 (±0.55) ^a
	Valine	7.49 (±0.12) ^a	7.27 (±1.09) ^a	11.3 (±1.34) ^b
Sweet whey powder	Glutamine	1.36 *^a	0.187 (±0.02) ^a	7.02 (±3.20) ^b
	Phosphocreatine	9.65 (±0.93) ^a	6.49 (±0.70) ^a	22.6 (±6.01) ^b
	Serine	25.3 (±3.11) ^b	18.7 (±2.33) ^a,b	9.31 (±0.64) ^a
Ideal whey powder	Glutamine	4.04 (±0.23) ^a	3.19 (±1.77) ^a	11.5 (±2.64) ^b
	Phosphocreatine	7.21 (±1.64) ^a	5.37 (±0.61) ^a	17.1 (±1.41) ^b
	Serine	21.9 (±1.13) ^b	18.8 (±1.27) ^a,b	9.62 (±1.10) ^a
	Valine	7.00 (±0.74) ^a	7.92 (±1.43) ^a,b	10.6 (±0.07) ^b
Acid whey powder	Glutamine	2.39 (±1.74) ^a	2.97 (±1.07) ^a	12.3 (±0.42) ^b
Acid whey powder	Valine	6.80 (±1.97) ^a	7.29 (±0.69) ^a	12.0 (±1.63) ^b

GRS—cows fed perennial ryegrass only. CLV—cows fed perennial ryegrass/20% white clover sward. TMR—cows fed indoor total mixed ration ad-libitum. ^a,b indicates values within a row not sharing a common superscript letter differed significantly (p < 0.05). * Denotes where a replicate was below the limit of detection or limit of quantification.