Impacts of Stocking Density on the Performance and Welfare of Broiler Chickens

Figures & data

Figure 1. Thermograms of head, neck, wing, body and shank thermograms of chicks belong to low (A), medium (B), and high (C) stocking rates.

Table 1. Dietary ingredients and chemical composition of starter and finisher diets.

	Experimental diet
	Starter	Finisher
Ingredients, g/kg
Corn	542.6	564.0
Soybean meal	361.0	341.0
Palm oil	54.0	59.0
Dicalcium phosphate	23.0	20.0
Ground limestone	7.20	7.00
DL-methionine	2.30	1.00
Salt	3.00	3.00
Vitamin premix^°	2.50	2.50
Trace mineral mix^#	0.50	0.50
Choline chloride60	1.00	0.50
Sodium bicarbonate	2.90	1.50
Calculated analysis
ME, kcal/kg	3100	3150
Crude protein, %	22.0	21.0
Lysine, %	1.20	1.10
Methionine, %	0.55	0.40
Threonine, %	0.84	0.81
TSAA, %	0.90	0.75
Calcium, %	1.00	0.90
Non-phytate phosphorus, %	0.45	0.40

°Vitamin-mix is supplied in the following per kg of diet: Retinyl acetate, 3.41 mg; cholecalciferol, 0.07 mg; DL-α-tocopheryl acetate, 27.5 mg; menadione sodium bisulphate, 6 mg; riboflavin, 7.7 mg; niacin, 44 mg; panthotenic acid, cyanocobalamin, 0.02; choline 496 mg; folic acid, 1.32 mg; pyridoxine HCl, 4.82 mg; thiamine mononitrate, 2.16 mg; D-biotin, 0.11 mg.

^#Mineral-mix is supplied in the following per kg of diet: manganese, 67 mg; zinc, 54 mg; copper, 2 mg; iodine, 0.5 mg; iron, 75 mg; and selenium, 0.2 mg. ME, metabolizable energy; TSAA, total sulfur amino acids.

Table 2. Characteristics parameters of meteorological measurements throughout the study.

	Time of measurement
	09:00 h		15:00 h
	Ta, °C	RH, %	Ta, °C	RH, %
Mesor	25.09±0.15	26.56±3.22	24.80±0.28	26.60±3.69
Zenith	25.17±0.10	32.80±1.25	25.16±0.19	33.00±1.43
Nadir	24.79±0.06	24.30±0.90	24.61±0.10	23.40±0.74
Thermal load	0.38±0.09	8.50±1.14	0.55±0.15	9.60±1.21

T_a, ambient temperature; RH, relative humidity. Data are reported as mean ±SD.

Table 3. Body weight gain, feed intake and feed conversion ratio at different ages of broiler chickens under different stocking density rates.

	Stocking density			SEM	P value
	Low	Medium	High
Performance at 16 d
BWG, g	490.4^a	452.1^a	354.4^b	18.4	^**
FI, g	736.6^a	715.6^a	594.6^b	25.6	^**
FCR, g:g	1.504^b	1.5827^ab	1.6829^a	0.032	^*
Performance at 30 d
BWG, g	898.5	877.4	790.8	28.6	ns
FI, g	1378.4	1401.3	1298.2	49.57	ns
FCR, g:g	1.5331	1.6127	1.6486	0.063	ns
Cumulative 0-30 d
BWG, g	1388.9^a	1329.5^a	1145.2^b	39.1	^**
FI, g	2115.0^a	2125.9^a	1892.8^b	63.7	^*
FCR, g:g	1.522	1.601	1.6586	0.046	ns

BWG, body weight gain; FI, feed intake; FCR, feed conversion ratio.

^abMeans in the row with different superscripts differ significantly.

^*P<0.05;

^**P<0.01; ns, not significant.

Table 4. Thermophysiological parameters as influenced by rates of stocking density.

	Stocking density		SEM		P value
	Low	Medium	High
Tb,°C	40.4^c	40.5^b	40.7^a	0.03	^***
Head Ts,°C	34.4^c	35.0^b	35.7^a	0.09	^***
Neck Ts,°C	31.6^c	32.5^b	33.2^a	0.19	^***
Wing Ts,°C	28.4^c	28.9^b	30.1^a	0.16	^***
Body Ts,°C	30.5^b	30.7^b	32.3^a	0.15	^***
Shank Ts,°C	34.5^c	35.3^b	36.5^a	0.09	^***

T_b, body temperature; T_s, surface temperature.

^abcMeans in the row with different superscripts differ significantly;

^***P< 0.001.

Table 5. Effect of stocking density on some hematological and biochemical parameters in broiler chicken.

		Stocking density		SEM	P value
	Low	Medium	High
PCV, %	30.3^a	28.0^b	26.5^c	0.63	^**
Total protein, g/dL	2.2	2.1	2.0	0.08	ns
Glucose, mg/dL	273.2	271.1	258.6	8.45	ns
AST, U/L	56.4^b	60.1^ab	68.7^a	5.56	^*

PCV, packed cell volume; AST, aspartate aminotransferase.

^abcMeans in the row with different superscripts differ significantly;

^*P<0.05;

^**P<0.01; ns, not significant.