TABLE 4.

Concentrations of amino acids in the serum of control and arginine-treated ewes at 1 h after administration on d 121 of pregnancy¹

	Treatment group			Litter size
Amino acid	Arginine, n = 20	Control, n = 14	P-value	Twins, n = 10	Triplets, n = 12	Quadruplets, n = 12	P-value
	μmol/L			μmol/L
Aspartate	5.1 ± 0.4	4.3 ± 0.5	0.18	5.3 ± 0.6	4.3 ± 0.5	4.4 ± 0.5	0.34
Glutamate	108 ± 4	108 ± 5	0.96	112 ± 6	108 ± 5	104 ± 6	0.64
Asparagine	22 ± 2	29 ± 2	0.03	26 ± 3	25 ± 2	26 ± 2	0.98
Serine	67 ± 3	66 ± 4	0.87	71 ± 5	68 ± 4	62 ± 4	0.39
Glutamine	135 ± 5	136 ± 7	0.96	140 ± 8	136 ± 7	130 ± 7	0.64
Histidine	31 ± 2	37 ± 3	0.13	38 ± 4	28 ± 3	37 ± 3	0.06
Glycine	339 ± 21	342 ± 26	0.93	408 ± 31a	320 ± 26b	294 ± 28b	0.03
Threonine	54 ± 7	71 ± 9	0.13	85 ± 11a	42 ± 9b	60 ± 9ab	0.02
Citrulline	103 ± 10	114 ± 13	0.52	142 ± 15a	93 ± 13b	90 ± 14b	0.03
Arginine	422 ± 24	149 ± 30	<0.01	273 ± 37	279 ± 31	304 ± 33	0.79
β-Alanine	8.3 ± 0.7	12 ± 0.9	<0.01	9.9 ± 1	9.5 ± 0.9	12 ± 1	0.29
Taurine	110 ± 9	99 ± 11	0.41	102 ± 13	100 ± 11	112 ± 12	0.73
Alanine	122 ± 10	157 ± 12	0.03	133 ± 14	162 ± 12	124 ± 13	0.10
Tyrosine	41 ± 5	70 ± 6	<0.01	48 ± 8	68 ± 7	50 ± 7	0.08
Tryptophan	24 ± 2	28 ± 3	0.23	28 ± 3	26 ± 3	24 ± 3	0.61
Methionine	10 ± 1	15 ± 1	<0.01	12 ± 2	12 ± 1	13 ± 1	0.84
Valine	71 ± 8	97 ± 10	0.04	90 ± 12	75 ± 10	87 ± 11	0.61
Phenylalanine	27 ± 2	37 ± 3	<0.01	33 ± 3	28 ± 3	34 ± 3	0.29
Isoleucine	46 ± 4	68 ± 5	<0.01	51 ± 6	58 ± 5	61 ± 6	0.52
Leucine	74 ± 7	92 ± 9	0.10	82 ± 10	73 ± 9	95 ± 9	0.23
Ornithine	165 ± 12	43 ± 15	<0.01	130 ± 19	84 ± 16	98 ± 16	0.18
Lysine	88 ± 7	89 ± 9	0.91	88 ± 10	80 ± 9	98 ± 9	0.38
Cysteine	115 ± 4	87 ± 5	<0.01	109 ± 6	99 ± 5	96 ± 5	0.24
Proline	143 ± 3	99 ± 3	<0.01	142 ± 4a	117 ± 4b	105 ± 4b	<0.01

¹Data are means ± SEM. Means in a row with superscripts without a common letter differ, < 0.05.