The present study was conducted after approval of Institutional Animal Ethics Committee laboratory of Agriculture departement of Ghardaia University, Algeria.
Animals, diets, and experimental protocol
The trial was carried out at a poultry production unit in the municipality of El Kouif Wilaya of Tébessa (Algeria) in a building with a surface area of 80 m², fitted with thermal insulation made of polystyrene panels.
The study was carried out over a rearing period of 48 days, in a closed henhouse equipped with pad-cooling fans and humidifiers ensuring good ambient conditions. The litter consisted of sieved wood shavings.
Two hundred day-old chicks of equal sex ratio (1:1), of Big Fast strain, weighing on average 37±2g, were randomly divided into 4 homogeneous batches of 50 subjects each. Each batch was subdivided into 10 packs of 05 animals, banded and numbered, forming a control batch and three experimental batches.
The seed cakes and dehydrated prickly pear husks were supplied by an agro-industrial processing unit producing vinegar and prickly pear oil, located in the commune of Sidi fredj Wilaya of Souk-Ahras in south-eastern Algeria. The chemical composition of these two by-products is shown in Table 1.
Table 1. Chemical composition of prickly pear processing by-products in % DM
|
|
seed cake
|
Dehydrated envelopes
|
Dry matter (DM)
|
94,3
|
94,5
|
Organic matter
|
98.3
|
91.3
|
Total nitrogenous materials
|
8.8
|
5.6
|
Raw cellulose
|
55
|
52.3
|
Fats and fats
|
2.7
|
4
|
Mineral materials
|
1.7
|
8.7
|
Non-nitrogenous extractive
|
31,7
|
29,4
|
Gross energy (kcal/kg of DM)
|
4443
|
4166
|
Metabolizable energy (kcal/kg of DM) *
|
1818
|
1710
|
Lysine (g/100g protein)
|
0,54
|
0,98
|
Methionine (g/100g protein)
|
0,32
|
0 ,52
|
Cystine (g/100g protein)
|
0,31
|
0,62
|
* estimated according to the formula of Carpenter and Clegg (1956) with M E (kcal/kg DM) = 35.3 x C P (%) + 79.5 x F (%) + 40.6 x NNE (%) + 199
(ME : Metabolizable energy, C P : Crude protein, F: Fat, NNE: Non-nitrogenous extractive).
|
Using the WUFFDA software for broiler feed formulation, four rations were constituted, with 0% (control feed), 20%; 30%, and 40% substitution of soya meal by prickly pear seed cake and maize by their husks for the different rearing phases (Table 2). Rations were distributed randomly for the four broiler groups.
For the first ten days and thanks to gas-powered cattle raisers, a temperature varying between 36 and 38°C was maintained, as well as a 24-hour illumination, which was then reduced to 12 hours during the day and 6 hours at night.
Table 2. Formulas (kg/100 kg feed) of starter (1-20 days), grower (21-33 days), and finisher (34-48 days) feed distributed to chickens according to the rate of substitution of corn by prickly pear husks and soybean meal by prickly pear seed
cake (FB).
|
|
|
Start
|
|
|
Growth
|
|
|
Finishing
|
|
Substitution rate (%)
|
0
|
10
|
20
|
30
|
0
|
10
|
20
|
30
|
0
|
10
|
20
|
30
|
Ingredients
|
|
|
|
|
|
|
|
|
|
|
|
|
Corn
|
61
|
55
|
49
|
43
|
64
|
58
|
51
|
45
|
70
|
63
|
56
|
49
|
Envelopes from FB
|
0
|
06
|
12
|
18
|
0
|
06
|
13
|
19
|
0
|
07
|
14
|
21
|
Soya cake
|
30
|
27
|
24
|
21
|
27
|
24
|
22
|
19
|
21
|
19
|
17
|
15
|
FB seed cake
|
0
|
03
|
06
|
09
|
0
|
3
|
5
|
08
|
0
|
02
|
4
|
06
|
From milling
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
Bi-calcium phosphorus
|
1,2
|
1,2
|
1,2
|
1,2
|
1,2
|
1,2
|
1,2
|
1,2
|
1,2
|
1,2
|
1,2
|
1,2
|
CMV
|
1,25
|
1,25
|
1,25
|
1,25
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
L-Lysine
|
0,15
|
0,15
|
0,15
|
0,15
|
0,5
|
0,5
|
0,5
|
0,5
|
0,5
|
0,5
|
0,5
|
0,5
|
DL-Methionine
|
0,4
|
0,4
|
0,4
|
0,4
|
0,3
|
0,3
|
0,3
|
0,3
|
0,3
|
0,3
|
0,3
|
0,3
|
Nutrient content in % DM
|
Metabolisable energy (Kcal/Kg of MS)
|
2890
|
2877
|
2847
|
2837
|
2840
|
2822
|
2812
|
2800
|
2990
|
3093
|
3120
|
3192
|
Crude protein (%)
|
21
|
18,2
|
20,3
|
20,4
|
20,3
|
19,1
|
19,1
|
19,1
|
18
|
17
|
17
|
16,5
|
Fat content (%)
|
2,8
|
5,4
|
5,2
|
5,0
|
2,9
|
3,2
|
5,1
|
4,9
|
3,0
|
5,0
|
4,9
|
4,7
|
Mineral materials (%)
|
3
|
3,5
|
3,8
|
4,09
|
2,7
|
3,4
|
3,7
|
4,1
|
2,9
|
3,2
|
3,6
|
4
|
Raw cellulose (%)
|
3,0
|
8,7
|
13,7
|
17,7
|
2,9
|
8,6
|
13,6
|
17,5
|
2,8
|
8,4
|
12,8
|
17,3
|
Lysine (%)
|
1,20
|
9,62
|
8,66
|
7,92
|
1,38
|
8,82
|
8,12
|
7,16
|
1,22
|
7,5
|
6,81
|
6,11
|
Methionine (%)
|
0,72
|
2,78
|
2,53
|
2,27
|
0,60
|
2,68
|
2,44
|
2,18
|
0,57
|
2,38
|
2,24
|
2,02
|
Water and feed were distributed ad-libitum and the refusal was weighed daily. Vaccination against Newcastle disease and infectious bronchitis was carried out at the 7th and 21st breeding farms and against Gumboro disease at 14 days of age (no booster vaccination). An anticoccidial was administered at 17 and 34 days of age for two successive days in drinking water. The animals were individually weighed at placement, 10; 20; 33, and 48 days of age. Mortality was recorded daily throughout the entire experiment.
At the end of the rearing, 30 chickens taken at random from each batch were sacrificed. The live weight, the weight of the warm and cold carcass, legs, head, feathers, gizzard, viscera, and liver were weighed. The average daily gain (ADG), average daily intake (ADI), and feed and liver were weighed. The average daily gain (ADG), average daily intake (ADI), and feed conversion ratio (FCR) were calculated. At 24 hours post-mortem, the pH was measured by direct insertion (~ 2 cm deep) of the electrode of a pH meter into the pectoral muscle of quails according to the method of EL Rammouz, [23]. Ash, protein, and fat content were determined and calculated according to the Aoac methods [24].
Statistical analysis
Descriptive statistics and single-factor analysis of variance (ANOVA) were performed with the SPSS software (version 18, 2008) for the analysis of performance, slaughter parameters, and meat chemical composition. The post hoc test by the application of the S.N.K (Student- Newman- Keules) and Duncan test, to estimate the significance or homogeneity between the different subsets (test of comparison between the means). The differences were considered significant with a 5% risk of error.