Digestible lysine requirement of broilers based on practical diet

Figures & data

Table 1 Composition of experimental diets.

	Treatments, digestible lysine %
	0.77	0.84	0.91	0.98	1.05	1.12
Ingredients
Corn, %	62.20	62.09	61.90	61.77	61.64	61.52
Soybean meal, %	23.64	23.65	23.66	23.67	23.68	23.68
Gluten meal, %	8.17	8.16	8.18	8.19	8.20	8.21
Corn oil, %	2.83	2.84	2.86	2.87	2.87	2.88
Dicalcium phosphate, %	0.89	0.88	0.98	0.98	0.98	0.98
Oyster shell, %	1.26	1.27	1.21	1.21	1.21	1.21
NaHCO3, %	0.17	0.20	0.24	0.29	0.33	0.38
Vitamin° and mineral# mix, %	0.50	0.50	0.50	0.50	0.50	0.50
Salt, %	0.14	0.12	0.09	0.06	0.03	0.001
DL-methionine, %	0.20	0.20	0.20	0.20	0.203	0.20
L-Lys HCL, %	-	0.09	0.18	0.26	0.35	0.44
L-arginine, %	-	-	-	-	0.003	-
Analysis results§
Metabolizable energy, Kcal/kg	3200	3200	3200	3200	3200	3200
Protein, %	18.25	18.40	18.40	18.50	18.50	18.50
Calcium, %	0.80	0.80	0.80	0.80	0.80	0.80
Available phosphorus, %	0.30	0.30	0.30	0.30	0.30	0.30
DCAB, meq/kg	192.80	192.50	192.50	192.50	192.50	192.50
Digestible methionine, %	0.53	0.53	0.53	0.53	0.53	0.53
Digestible methionine+cystine, %	0.83	0.83	0.83	0.83	0.83	0.83
Digestible threonine, %	0.68	0.68	0.68	0.68	0.68	0.68
Digestible isoleucine, %	0.80	0.80	0.80	0.80	0.80	0.80
Digestible arginine, %	1.19	1.19	1.19	1.19	1.19	1.19
Digestible tryptophan, %	0.19	0.19	0.19	0.19	0.19	0.19
Digestible leucine, %	2.07	2.06	2.06	2.06	2.06	2.06
Digestible valine, %	0.88	0.88	0.88	0.88	0.88	0.88
Crude fibre, %	3.13	3.13	3.12	3.12	3.12	3.12

§ Finisher period from 35 to 49 d of age. The diet contained (by calculation) 3200 kcal of metabolizable energy/kg and 18.50% crude protein; it also contained 0.77, 0.84, 0.91, 0.98, 1.05 and 1.12% digestible lysine; total lysine as determined by analysis of diet.

° Vitamin mix provided the following (per kg of diet): thiamin-mononitrate, 2.4 mg; nicotinic acid, 44 mg; riboflavin, 4.4 mg; D-Ca pantothenate, 12 mg; vitamin B₁₂ (cobalamin), 12.0 mg; pyridoxine HCL, 4.7 mg; D-biotin, 0.11 mg; folic acid, 5.5 mg; menadione sodium bisulfate complex, 3.34 mg; choline chloride, 220 mg; cholecalciferol, 27.5 mg; transretinyl acetate, 1892 mg; all-rac α tocopheryl acetate, 11 mg; ethoxyquin, 125 mg.

# Trace mineral mix provided the following (per kg of diet): manganese (MnSO4-H2O), 60 mg; iron (FeSO4-7H2O), 30 mg; zinc (ZnO), 50 mg; copper (CuSO₄-5H₂O), 5 mg; iodine (ethylene diamine dihydroiodide), 0.15 mg; selenium (NaSe0₃), 0.3 mg. All of the amino acids were adjusted to broiler requirements in this period except lysine.

Table 2 Results of estimation for the digestible lysine requirement base on different parameters.

Method	Trait	Sex	Equation	R^2	Estimation of digestible lysine requirement
					% of feed intake	mg per day
Broken-line	Body weight	Male	Y=3083.3-3558.9(0.93-XLR)	0.996	0.93	2664.82
	Feed conversation rate		Y= 1.79+1.51(0.98-XLR)	0.995	0.98	2808.09
	Free lysine		Y=239.3-318.4(1.15-XLR)	0.980	1.12<	-
	Sheep red blood cell		Y=5.65-3.52(1.05-XLR)	0.993	1.05	3008.67
	Heterophil/lymphocyte		Y=0.61-0.42(1.11-XLR)	0.996	1.11	3180.59
	A.T°		Y=11.94-5.28(1.15-XLR)	0.995	1.12<	-
	Ig#		Y=3.70-4.72(1.08-XLR)	0.996	1.08	3094.63
	Abdominal fat		Y=1.79+3.66(0.98-XLR)	0.997	0.98	2808.09
	Breast meat		Y=14.93+31.34(1.34-XLR)	0.991	1.12<	-
Exponential	Body weight	Male	Y=2441.4+672.8[1-e-^11.24(X-0.77)]	0.722	1.036	2968.55
	Feed conversation rate		Does not fit		-	- -
	Free lysine		Does not fit		-	- -
	Sheep red blood cell		Does not fit		-	- -
	Heterophil/lymphocyte		Y=-0.35+0.27[1-e-^9.24(x-0.77)]	0.690	1.09	3123.29
	A.T°		Y=4.30+4.72[1-e-^1.72(x-0.77)]	0.681	1.12<	-
	Ig#		Y=2.16+1.62[1-e-^5.66(x-0.77)]	0.584	1.12<
	Abdominal fat		Y=3.01-1.30[1-e-^6.50(x-0.77)]	0.730	1.12<	-
	Breast meat		Y=35.87-11.36[1-e-^4.47(X-0.77)]	0.747	1.12<	-
Quadratic	Body weight	Male	Y=-8405.4+22642.5X-11111.5X^2	0.960	1.02	2922.71
	Feed conversation rate		Does not fit		-	- -
	Free lysine		Does not fit		-	- -
	Sheep red blood cell		Y=0.95+3.81X-0.46X^2	0.962	1.12<	-
	Heterophil/lymphocyte		Y=-2.78+6.34X-2.99X^2	0.955	1.06	3037.32
	A.T°		Y=-5.37+17X-5.78X^2	0.922	1.12<	-
	Ig#		Y=-12.25+28.90X-13.26X^2	0.945	1.09	3123.29
	Abdominal fat		Y=15.27-24.70X+11.39X^2	0.961	1.08	3094.63
	Breast meat		Y=254-459.9X+229.2X^2	0.970	1	2865.54
Broken-line	Body weight	Female	Y=2583.4-3892.3(0.93-XLR)	0.997	0.93	2169.97
	Feed conversation rate		Y=1.85+3.21(0.94-XLR)	0.993	0.94	2193.30
	Free lysine		Y=220-342.9(1.06-XLR)	0.990	1.06	2473.30
	Sheep red blood cell		Y=5.35-4.66(1.05-XLR)	0.996	1.05	2449.96
	Heterophil/lymphocyte		Y=0.72-0.68(1.03-XLR)	0.994	1.03	2403.30
	A.T°		Y=6. 40-6.3(1.04-XLR)	0.997	1.04	2426.63
	Ig#		Y=3.7-2.45(0.96-XLR)	0.996	0.96	2239.97
	Abdominal fat		Y=2.09+3.73(0.96-XLR)	0.996	0.96	2239.97
	Breast meat		Y=24.34+55.04(1.10-XLR)	0.994	1.10	2566.63
Exponential	Body weight	Female	Y=1894.1+700.6[1-e-^12.5(x-0.77)]	0.586	1.009	2354.30
	Feed conversation rate		Y=2.34-0.45[1-e-^12(x-0.77)]	0.645	1.02	2379.97
	Free lysine		Does not fit		-	-
	Sheep red blood cell		Y=3.85+5.02[1-e-^1.39(x-0.77)]	0.656	1.12 <
	Heterophil/lymphocyte		Does not fit	-	-	-
	A.T°		Y=4.42+2.66[1-e-^5.34(x-0.77)]	0.70	1.12<	-
	Ig#		Does not fit	-	-	-
	Abdominal fat		Does not fit	-	-	-
	Breast meat		Does not fit	-	-	-
Quadratic	Body weight	Female	Y=-10203+25369.7X-12537.9X^2	0.961	1.01	2356.63
	Feed conversation rate		Y=10.97-18.23X+9.11X^2	0.965	1	2333.30
	Free lysine		Does not fit	-	-	-
	Sheep red blood cell		Y=-4.31+14.07X-4.54X^2	0.940	1.12<	-
	Heterophil/lymphocyte		Y=-3.82+9.02X-4.43X^2	0.894	1.02	2379.97
	A.T°		Y=-14.95+38.21X-16.91X^2	0.931	1.129	2636.63
	Ig#		Y=0.95+2.49X-0.10X^2	0.940	1.12<	1134.98
	Abdominal fat		Y=6.87-9.77X+5.03X^2	0.970	0.97	2263.30
	Breast meat		Y=350.2-663.5X+335.9X^2	0.964	0.99	2309.97

° Antibody titration against of Newcastle;

# immunoglobulin.

Table 3 Effects (interaction sex × lysine) of digestible lysine levels on carcass parameters of male and female broilers.

Sex	Digestible lysine, %	Breast weight, %	Abdominal fat, g/kg BW
Male	0.77	23.66±1.54^d	2.51±0.54^bc
	0.84	24.03±1.72^d	2.35±0.47^abc
	0.91	25.78±1.17^d	2.00±0.27^ab
	0.98	29.36±2.75^c	1.80±0.25^a
	1.05	36.37±3.49^a	1.76±0.26^a
	1.12	33.49±2.68^ab	1.81±0.26^a
Female	0.77	23.32±1.26^d	2.82±0.56^c
	0.84	24.10±2.63^d	2.54±0.49^bc
	0.91	24.89±1.15^d	2.30±0.26^abc
	0.98	25.33±3.38^d	2.01±0.21^ab
	1.05	30.50±2.2^8^bc	2.11±0.22^ab
	1.12	25.17±3.02^d	2.16±0.06^ab

BW, body weight;

a-d means with different superscripts within same row are significantly different.

Figure 1 Comparison of digestible lysine requirements based on performance, breast meat yield and immune response.

Table 4 Comparison of digestible lysine (in percentage) requirement estimate base on performance, blood parameters and immune response.

	Performance		Immune response		Blood parameters
Sex	BW	FCR	H/L	Antibody against SRBC	Antibody against Newcastle	Total Ig	Free lysine of plasma
Male	0.93	0.98	1.11	1.05	1.15	1.08	1.15
Female	0.93	0.92	1.03	1.05	1.04	0.96	1.06

BW, body weight; FCR, feed conversation rate; SRBC, sheep red blood cell; H/L, heterophil/lymphocyte.

Table 5 The effects (interaction sex × lysine) of digestible lysine levels on growth performance of male and female broilers.

Sex	Digestible lysine, %	BWG, g	FI, g	FCR
Male	0.77	2000.75±53.32^e	3721.40±669.75^ab	1.86±0.27^abc
	0.84	2250.03±44.06^c	3982.55±655.56^ab	1.77±0.23^abc
	0.91	2499.00±41.30^b	4148.34±636.15^a	1.66±0.22^ab
	0.98	2600.03±47.95^a	4004.00±801.64^ab	1.54±0.25^ab
	1.05	2650.00±45.83^a	3895.50±788.79^ab	1.47±0.27^a
	1.12	2499.93±17.81^b	4074.89±731.39^a	1.63±0.25^ab
Female	0.77	1450.10±48.66^g	2972.71±512.05^b	2.05±0.26^c
	0.84	1700.02±71.47^f	3213.04±427.95^ab	1.89±0.19^bc
	0.91	1995.02±34.93^e	3192.03±566.94^ab	1.60±0.22^ab
	0.98	2150.00±40.01^d	3332.50±615.57^ab	1.55±0.24^ab
	1.05	2100.00±45.85^d	3399.00±696.27^ab	1.59±0.30^ab
	1.12	2000.05±18.97^e	3240.08±633.96^ab	1.62±0.26^ab

BW, body weight; FI, feed intake; FCR, feed conversation rate;

a-d means with different superscripts within same row are significantly different.

Table 6 Effects (interaction sex × lysine) of digestible lysine levels on blood parameters of male and female broilers.

Sex	Digestible lysine, %	Total protein, mg/dL	Albumin, mg/dL	Free lysine of plasma, ŋmol/mL	Urea nitrogen, mg/dL	Uric acid, mg/dL	Creatinin, mg/dL
Male	0.77	3.39±0.42^d	1.20±0.43^ab	130±12.00^a	4.50±0.49^a	8.90±0.77^f	0.54±0.07^ab
	0.84	3.90±0.46^cd	1.30±0.55^ab	150±9.76^ab	4.08±0.52^ab	9.70±0.62^def	0.50±0.03^abc
	0.91	4.30±0.54^c	1.31±0.52^ab	140±13.64^ab	3.60±0.67^bc	10.45±0.68^bcde	0.44±0.08^bcd
	0.98	4.50±0.52^bc	1.41±0.45^ab	160±19.11^b	2.43±0.57^d	11.52±0.91^ab	0.58±0.09^a
	1.05	5.40±0.51^a	1.80±0.52^b	220±8.79^cd	2.70±0.25^d	10.3±0.50^cde	0.40±0.06c^d
	1.12	5.50±0.50^a	1.80±0.39^b	240±18.26^d	3.40±0.26^c	9.50±0.55^ef	0.43±0.06^cd
Female	0.77	4.00±0.50^cd	1.00±0.44^a	130±14.72^a	2.49±0.41^d	10.00±0.63^def	0.47±0.06^bc
	0.84	4.30±0.49^c	1.10±0.36^ab	140±11.11^ab	2.19±0.44^d	11.40±0.66^abc	0.45±0.04^bcd
	0.91	4.20±0.43^c	1.30±0.49^ab	150±17.44^ab	1.40±0.28^ef	12.30±0.69^a	0.50±0.06^abc
	0.98	5.11±0.66^ab	1.60±0.49^ab	200±14.51^c	0.94±0.29^f	11.20±0.60^abc	0.35±0.06^d
	1.05	5.20±0.46^ab	1.50±0.42^ab	220±12.36^cd	0.90±0.10^f	10.70±0.44^bcd	0.35±0.06^d
	1.12	5.30±0.45^a	1.60±0.38^ab	220±11.55^cd	1.60±0.14^e	10.00±0.48^def	0.45±0.06^bcd

a-f Means with different superscripts within same row are significantly different.

Table 7 Effects (interaction sex × lysine) of digestible lysine levels on blood parameters and immune response of male and female broilers.

Sex	Digestible lysine, %	SRBC, Log2	Total IG, mg/dL	H/L	Hematocrit, %	Hemoglubolin, g/dL
Male	0.77	4.52±0.48^c	2.19±0.01^c	0.47±0.14^c	31.75±4.22^a	10.27±0.7^3^f
	0.84	4.55±0.49^c	2.60±0.09^bc	0.49±0.10^c	31.83±2.79^a	10.73±0.69^ef
	0.91	4.59±0.44^c	2.99±0.51^ab	0.54±0.15^bc	32.29±3.05^a	11.47±0.74^cde
	0.98	4.68±0.47^bc	3.09±0.69^ab	0.52±0.11^bc	32.67±2.09^a	12.22±0.66^bcd
	1.05	5.58±0.35^a	3.60±0.60^a	0.60±0.12^abc	33.51±2.10^a	13.00±0.57^ab
	1.12	5.61±0.39^a	3.70±0.74^a	0.61±0.09^abc	33.60±2.67^a	13.43±0.53^a
Female	0.77	4.24±0.50^c	3.00±0.07^ab	0.55±0.10^bc	30.08±3.14^a	10.14±0.78^f
	0.84	4.27±0.37^c	3.20±0.13^ab	0.61±0.15^abc	30.27±2.60^a	10.50±0.63^ef
	0.91	4.32±0.60^c	2.89±0.21^abc	0.62±0.11^abc	30.54±3.22^a	11.34±0.58^de
	0.98	5.31±0.44^ab	3.51±0.18^a	0.71±0.14^ab	31.14±1.55^a	12.38±0.74^bc
	1.05	5.35±0.35^ab	3.70±0.47^a	0.75±0.10^a	31.56±2.00^a	12.45±0.46^bc
	1.12	5.35±0.35^ab	3.70±0.50^a	0.70±0.11^ab	31.22±1.66^a	12.25±0.41^bcd

SRBC, sheep red blood cell; IG, immunoglobulin; H/L, heterophil/lymphocyte;

a-f means with different superscripts within same row are significantly different.