Table 5.

Effects of different levels of taurine on serum and liver lipid metabolism in broilers.

Items	Dietary taurine concentration treatment3				SEM1	P Value
	CON	TAU1	TAU2	TAU3		Linear2	Quadratic2
Serum
TC (mmol/L)	4.219a	3.996b	3.959b	4.052a,b	0.035	0.072	0.021
TG (mmol/L)	0.421a	0.339b	0.359b	0.350b	0.012	0.052	0.093
NEFA (u mol/L)	987.645	1,002.180	986.192	1,046.512	12.718	0.164	0.370
HDL-C (mmol/L)	3.127b	3.429a,b	3.617a	3.412a,b	0.067	0.070	0.051
LDL-C (mmol/L)	0.962	0.899	0.929	0.919	0.027	0.696	0.640
LPL (U/mL)	1.966	1.955	1.796	1.921	0.033	0.328	0.306
HL (U/mL)	2.826a	2.283b	2.212b	2.228b	0.055	<0.001	<0.001
TL (U/mL)	4.791a	4.237b	4.008b	4.149b	0.066	<0.001	<0.001
Liver
TC (mmol/g prot)	0.099	0.093	0.093	0.103	0.004	0.767	0.368
TG (mmol/g prot)	3.017a	2.478b,c	2.289c	2.760a,b	0.085	0.150	0.002
NEFA (u mol/g prot)	103.142	100.165	91.958	100.194	3.118	0.554	0.386
LPL (U/mg prot)	1.330b	1.505a	1.461a,b	1.530a	0.032	0.022	0.828
HL (U/mg prot)	1.481	1.494	1.580	1.545	0.017	0.065	0.464
TL (U/mg prot)	2.811b	2.999a,b	3.041a,b	3.075a	0.039	0.008	0.606
ACC (pg/mg prot)	9.410	9.256	9.273	9.373	0.059	0.862	0.310
FAS (pg/mg prot)	582.583a	559.667b	563.208a,b	561.958a,b	3.824	0.054	0.147
HSL (pg/mg prot)	36.942b	37.132b	39.434a	38.300a,b	0.325	0.018	0.254

^a–cMeans within the same row with no common superscript differ significantly (P < 0.05).

Abbreviatioons: ACC, acetyl CoA carboxylase; FAS, fatty acid synthase; HDL-C, high-density lipoprotein cholesterol; HL, hepatic lipase; HSL, hormone-sensitive triglyceride lipase; LDL-C, low-density lipoprotein cholesterol; LPL, lipoprotein lipase; NEFA, nonesterified fatty acid; TC, total cholesterol; TG, triglycerides; TL, total lipase.

¹Standard error of the means (n = 8).

²Orthogonal polynomials were used to evaluate linear and quadratic responses to the levels of taurine treatment.

³CON, basal diet; TAU1, TAU2 and TAU3 group, basal diet adding 2.50, 5.00, and 7.50 g/kg TAU, respectively.