Table 3.

Effects of increasing mammary glucose supply on the mammary gland uptake of AA in lactating dairy goats¹

Items2	Infused glucose, g/d						SEM	P-value
	0	20	40	60	80	100		Linear	Quadratic	Cubic
Essential AA, mmol/d
Arg	12.3	14.5	15.9	23.6	14.3	9.32	5.01	0.96	0.06	0.78
His	10.2	8.18	12.7	17.2	17.4	7.20	5.24	0.81	0.22	0.15
Ile	15.7	19.2	25.2	32.4	17.9	14.3	5.32	0.95	0.02	0.68
Leu	16.7	21.4	27.2	31.8	21.1	19.5	4.13	0.32	< 0.01	0.74
Lys	11.8	13.5	22.9	26.9	17.7	14.2	1.86	0.39	< 0.01	0.50
Met	2.97	3.96	6.38	7.52	5.21	3.34	1.18	0.80	< 0.01	0.92
Phe	10.3	11.9	13.9	16.7	10.1	11.2	1.98	0.76	0.04	0.81
Thr	11.2	15.4	16.7	18.8	15.1	13.4	2.29	0.57	0.02	0.28
Val	16.1	16.7	20.5	24.6	20.8	15.9	2.21	0.39	< 0.01	0.24
Non-essential AA, mmol/d
Ala	14.6	13.2	20.3	15.5	11.7	10.3	3.34	0.51	0.58	0.91
Asx	2.88	1.42	2.05	2.04	4.41	1.52	0.87	0.99	0.74	0.13
Cys	3.06	4.38	7.14	8.03	4.58	3.53	1.22	0.36	< 0.01	0.64
Glx	19.2	25.3	38.8	44.9	32.3	20.2	4.63	0.26	< 0.01	0.90
Gly	4.55	5.04	11.1	9.95	8.01	5.83	2.89	0.67	0.08	0.87
Pro	9.20	11.5	13.6	11.9	14.2	9.3	4.55	0.69	0.25	0.25
Ser	11.5	17.1	22.3	23.5	13.2	12.8	4.84	0.81	0.03	0.57
Tyr	8.80	10.6	10.9	12.1	9.50	10.1	1.82	0.69	0.15	0.67
Essential AA, mmol/d	107	125	161	200	140	108	23.2	0.49	< 0.01	0.26
Non-essential AA, mmol/d	73.8	88.5	126	128	97.9	73.6	14.2	0.58	0.04	0.62
Group-1 AA, mmol/d	32.3	34.6	43.9	53.5	42.2	31.8	8.25	0.70	0.07	0.86
Group-2 AA, mmol/d	83.8	100	128	158	107	86.6	19.9	0.65	0.01	0.50
Branched-chain AA, mmol/d	48.5	57.3	72.9	88.8	59.8	49.7	10.1	0.70	< 0.01	0.59
Total AA, mmol/d	181	213	288	327	238	182	33.4	0.59	< 0.01	0.45

¹ Mammary gland uptake of AA (mmol/d) = (arterial − venous difference) (mmol/L) × mammary gland plasma flow (L/d)

² Glx: glutamate + glutamine; Asx: aspartate + asparagines; Group-1 AA: His, Met, Phe, and Tyr; Group-2 AA: Arg, Ile, Leu, Lys, Thr, and Val; Branched-chain AA: Ile, Leu, and Val