ns: not significant, **: P<0.01, ***: p<0.001, Er: Ermine, Gs: Gray-shank, Cr:Crested, Nn: Naked-neck
Figure 1. Fertility rate in four genotypes of the local Algerian chicken raised at the station
| Livestock Research for Rural Development 33 (2) 2021 | LRRD Search | LRRD Misssion | Guide for preparation of papers | LRRD Newsletter | Citation of this paper |
The current study was conducted to determine the influence of the breeding system on the reproduction of local chickens in Algeria and to compare the performances of 4 different genotypes in order to bring out the most performing. This study involved 663 chickens (526 females and 137 males) regrouped into 4 different genotypes: 135 Ermine (Er), 145 Naked-neck (Nn), 180 Gray-shank (Gs) and 203 Crested (Cr), raised in a semi-intensive system at the experimental station of the Technical Institute of Livestock, Tlemcen (ITElv for “Institut Technique des Elevages”) during 6 years (2012 to 2016).
The zootechnical performances differed from a genotype to another. The Gs genotype showed the highest reproduction parameters (weight at start of lay 1.22 ± 0.11 kg, average egg weight 52.4 ± 4.6 g and number of eggs laid per month 21.7 ± 11.0) compared to other genotypes. Concerning the incubation parameters, the Nn genotype had the lowest values for fertility and hatching rates (42.9% and 32.7% respectively). It should be noted that the performances reported in the station are improved and superior to those reported in rural areas. The significant differences observed between the studied genotypes indicate that the variations in the studied parameters can be used in programs aiming to improve the local pool by crosses and / or selections; it indicates a possibility of improving the growth performance of local chickens through the improvement of breeding and feeding conditions.
Keywords: breeding system, local chicken, genotype, reproduction parameter
Poultry farming is an important source of income and animal protein. Thus, the promotion of village poultry farming and the gradual improvement of the zootechnical performances of poultry of local breeds can be both a source of economic development and safeguard of biodiversity (Fotsa 2008). The poultry production systems in Africa are based on husbandry of indigenous chickens found in virtually all villages and households in rural communities characterized by a low output per bird (Aiyedun and Oludairo 2016). Most often, local chickens are classified according to their geographic locations or their phenotypes. Unfortunately, these varieties are still very poorly characterized and their potential for production, adaptation to climates and breeding conditions and their resistance to diseases have been little studied. In Algeria, as in other African countries, the traditional poultry farming was, until the 1960s, the only source of poultry products. However, the development of the industrial sector has led to the progressive marginalization of the traditional sector based exclusively on the exploitation of chicken local populations which have proven qualities of adaptation allowing the success of breeding projects in difficult rural conditions (Mahammi 2015). In order to sustain rural poultry and increase animal protein and income of the rural poultry, the owner’s effort should be geared toward the improvement of management and health status of rural poultry there by promoting livestock production, development and creating wealth (Aiyedun and Oludairo 2016).
This work aims to study the performance of Algerian local chickens in an experimental environment and to compare them with this performance in a rural environment in order to analyze the effect of the improvement of breeding conditions on the productivity of the local chicken. On the other hand, it compares the performances of 4 groups of different genotypes in order to bring out the best performing genotype.
The work was carried out in collaboration with the Technical Institute of Livestock (ITElv) in the province of Tlemcen, on the extreme west of Algeria. It is a public administrative establishment serving animal husbandry. It was created by the executive decree n ° 99/42 of February 13, 1999. This institute has some objectives like to promote breeding techniques, to enhance livestock products, to promote techniques for processing animal production, to implement selection schemes and crossbreeding for the genetic improvement of animal species as well as the preservation of the animal genetic heritage and to set up and organize models to control zootechnical performances. In the case of the local chicken ( Gallus gallus domesticus), the ITElv aims to set up a program of valorization and improvement of this population by the knowledge of the parameters of reproduction and growth.
This study was carried from 2011 to 2016 and involved 663 chickens: 526 females weighing on average 1.20 ± 0.09 kg and 137 males of 1.60 ± 0.12 kg. These animals are regrouped in four different genotypes: Ermine, Gray-shank, Crested and Naked-neck. Table 1 shows the number of animals by genotype.
|
Table 1. Number of birds by genotype |
|||
|
Genotype |
Females |
Males |
Total |
|
Ermine (Er) |
106 |
29 |
135 |
|
Gray-shank (Gs) |
148 |
32 |
180 |
|
Crested (Cr) |
160 |
43 |
203 |
|
Naked-neck (Nn) |
112 |
33 |
145 |
|
Total |
526 |
137 |
663 |
The experimental station of the ITElv of Tlemcen, intended for the breeding of the local chicken, is equipped by an aviary divided into four compartments each of them comprises a nest plus the necessary breeding equipment (feeders, drinkers); an incubator and a hatcher; a four-cell chickens brooder with suitable equipment for breeding (feeders, drinkers, gas radiant).
The chickens were placed in four compartments of the same aviary. The surface of each aviary is 17 square meters, the density per square meter was 7 subjects and whose sex ratio was 1 male for 6 females for each genotype. The eggs were collected and weighed daily, then wrapped in aluminum foil and stored for 30 days for a maximum of eggs before being placed in the incubator. The hatched chicks were in turn weighed before being placed in the chickens aviary by genotype, the density per square meter was 10 subjects.
The feed distributed for chickens was of the classic broiler type. The subjects intended for reproduction received a pre-laying feed until the 18th week of age when we began to distribute the laying feed (laying chicken).
We have collected all the data relating to the zootechnical performance of the four genotypes of the local chikens, by studying the breeding technical sheets provided by the manager in charge of the ITElv of Tlemcen. These sheets provide monthly reviews of the conduct and results of breeding.
The parameters used in this study were: age of entry in lay, weight of females at the start of lay, number of eggs laid per female, average weight of the egg.
Some incubations parameters were used:
• Fertility rate: it tells us about the percentage of eggs fertilized, it refers to the fertility of the roosters; it was calculated as follows:
• Fertility rate (%) = [(number of eggs incubated - number of clear eggs) / number of eggs incubated] * 100
• Hatching rate: it determines the quality of the hatching eggs; it was assessed as follows:
Hatching rate (%) = [(number of eggs / number of eggs incubated] * 100
• Embryo mortality rate: the ratio of the number of unhatched eggs to the total number of eggs incubated
Embryo mortality rate (%) = [(number of unhatched eggs / number of eggs incubated] * 100.
The parameter used was:
• Growth = average weight / phase.
|
Table 2. Estimation of the reproduction parameters in 4 genotypes of the local Algerian chicken raised in the station |
||||||||
|
Parameters |
Total |
Ermine |
Gray-shank |
Crested |
Naked-neck |
p |
||
|
Global |
||||||||
|
Age at start of lay (months) |
5.5 |
5.38 |
5.49 |
5.42 |
5.88 |
0.68 |
||
|
Weight at start of lay (kg) |
1.14 |
1.09a |
1.22b |
1.11a |
1.15a |
<0.001*** |
||
|
Eggs laid per month |
19.3 |
20.2a |
21.7b |
17.3a |
17.9a |
<0.05* |
||
|
Average egg weight (g) |
49.6 |
52.1b |
52.4b |
50.7ab |
49.5a |
<0.01** |
||
|
Per year |
||||||||
|
Year 2011 |
||||||||
|
Age at start of lay (months) |
5.53 |
5.45 |
5.45 |
5.42 |
5.80 |
0.885 |
||
|
Weight at start of lay (kg) |
1.31 |
1.35 |
1.39 |
1.32 |
1.18 |
0.000125 *** |
||
|
Eggs laid per month |
18.2 |
19.5 |
19.7 |
17.3 |
16.1 |
0.298 |
||
|
Average egg weight (g) |
51.2 |
52.1 |
52.4 |
50.7 |
49.5 |
0.00634 ** |
||
|
Year 2012 |
||||||||
|
Age at start of lay (months) |
6.55 |
6.25 |
6.25 |
6.25 |
7.75 |
0.660 |
||
|
Weight at start of lay (kg) |
1.30 |
1.32 |
1.37 |
1.19 |
1.38 |
0.00524 ** |
||
|
Eggs laid per month |
22.3 |
25.9 |
23.5 |
16.1 |
23.5 |
0.120 |
||
|
Average egg weight (g) |
51.7 |
52.0 |
54.4 |
51.2 |
49.2 |
0.00821 ** |
||
|
Year 2013 |
||||||||
|
Age at start of lay (months) |
5.02 |
4.94 |
4.94 |
4.94 |
5.28 |
0.360 |
||
|
Weight at start of lay (kg) |
1.16 |
1.12 |
1.28 |
1.14 |
1.14 |
4.59e-06 *** |
||
|
Eggs laid per month |
15.7 |
17.6 |
19.8 |
11.1 |
13.6 |
0.216 |
||
|
Average egg weight (g) |
49.6 |
50.0 |
51.5 |
49.6 |
47.3 |
0.00568 ** |
||
|
Year 2014 |
||||||||
|
Age at start of lay (months) |
4.62 |
4.50 |
4.50 |
4.50 |
5.00 |
0.543 |
||
|
Weight at start of lay (kg) |
1.12 |
1.02 |
1.23 |
1.07 |
1.15 |
0.00521 ** |
||
|
Eggs laid per month |
20.4 |
21.8 |
24.3 |
19.8 |
15.9 |
0.0445* |
||
|
Average egg weight (g) |
51.1 |
51.9 |
53.4 |
51.3 |
48.8 |
4.63e-13 *** |
||
|
Year 2015 |
||||||||
|
Age at start of lay (months) |
6.55 |
6.25 |
6.25 |
6.25 |
7.75 |
0.660 |
||
|
Weight at start of lay (kg) |
1.14 |
1.07 |
1.20 |
1.12 |
1.18 |
0.0345 * |
||
|
Eggs laid per month |
19.6 |
15.5 |
21.9 |
17.7 |
24.3 |
0.049* |
||
|
Average egg weight (g) |
49.9 |
49.3 |
52.0 |
48.6 |
48.7 |
0.0435 * |
||
|
Year 2016 |
||||||||
|
Age at start of lay (months) |
5.15 |
4.5 |
4.5 |
4.5 |
5.58 |
0.877 |
||
|
Weight at start of lay (kg) |
1.04 |
1.02 |
1.12 |
1.03 |
1.11 |
0.0445 * |
||
|
Eggs laid per month |
15.8 |
16.3 |
22.5 |
22.0 |
12.5 |
0.0122 * |
||
|
Average egg weight (g) |
54.6 |
54.1 |
57.5 |
54.0 |
52.9 |
0.00545 ** |
||
|
abcd Means within rows with different superscripts are different (P<0.05) |
||||||||
We used R version 3.2.2 software to perform the various statistical analyzes. A descriptive analysis made it possible to highlight the average of each parameter. Student's t-test and Anova test were used to compare the different means at the theoretical threshold α = 0.05.
The reproduction parameters are recorded in Table 2. The age at start of laying did not differ between the four genotypes. The statistical tests showed that there were significant differences between the four genotypes for the weight at start of lay (p <0.001), for the average egg weight (p <0.01) and also for the number of eggs laid per month (p <0.05).
The lowest age at the start of laying was observed in the Ermine genotype (5.38± 1.67 months), while the highest was observed in chicken with Naked-neck genotype (5.88± 1.86 months) without statistical difference. The lowest body weight at the start of laying was observed the Ermine genotype (1.09± 0.17 kg); it was intermediate in the Crested and the Naked-neck genotypes (1.11± 0.08 kg and 1.15± 0.08 kg respectively) and it was higher the Gray-shank genotype (1.22± 0.11 kg). The number of eggs laid per month was lowest in Crested chicken (17.3± 7.9 eggs/month), intermediate in Naked-neck and Ermine chicken (respectively, 17.9± 9.2 and 20.2± 6.5 eggs/month), and higher in Gray-shank genotype (21.7± 11.0 eggs/month); on average it was 19.3± 8.8 eggs/month in the total population. The lowest egg weight was recorded in the Naked-neck chicken (49.5± 4.7 g) and the highest in the Gray-shank genotype (52.4 ± 4.6 g).
The differences observed between the genotypes studied in terms of reproduction parameters were recurred over the years of the study (Table 2).
According to these results, it seems that chickens with the Gray-shank genotype were distinguished by the highest reproduction parameters (weight at start of lay, the average egg weight and number of eggs laid per month) compared to other genotypes.
The values of reproductive performance recorded in our study were similar to the results of work carried out on the performance of the local chicken in a controlled environment in Senegal (Missohou et al 2002), in Nigeria (Sarkar and Bell 2006), in Cameroon (Fotsa 2008) and in Côte d'Ivoire (Kouadio et al 2013).
The results of the estimation of the incubation performances are summarized in Table 3. There were significant differences (P <0.001) between the four genotypes for the hatching rate and the fertility rate but not for the chick mortality rate. The same observations were recurred over the 6 years of the study.
|
Table 3. Estimation of incubation performance in four genotypes of the local Algerian chicken raised in the station |
||||||
|
Parameters |
Total |
Naked-neck |
Ermine |
Crested |
Gray-shank |
p |
|
Global |
||||||
|
Fertility rate (%) |
51.4 |
42.9a |
52.9b |
53.7b |
56.4b |
<0.001 |
|
Embryo mortality rate (%) |
9.50 |
10.5a |
8.31a |
9.93a |
9.23a |
0.36 |
|
Hatching rate (%) |
41.9 |
32.7a |
44.7b |
47.2b |
45.4b |
<0.001 |
|
Per year |
||||||
|
Year 2011 |
||||||
|
Fertility rate (%) |
46.6 |
39.6 |
47.1 |
47.5 |
49.6 |
<0.05 |
|
Embryo mortality rate (%) |
7.57 |
5.79 |
8.55 |
8.41 |
7.54 |
0.28 |
|
Hatching rate (%) |
39.0 |
33.8 |
41.1 |
39.0 |
42.0 |
<0.05 |
|
Year 2012 |
||||||
|
Fertility rate (%) |
27.1 |
22.3 |
27.7 |
27.56 |
33.4 |
<0.05 |
|
Embryo mortality rate (%) |
13.6 |
15.5 |
9.96 |
15.0 |
14.0 |
0.45 |
|
Hatching rate (%) |
19.3 |
15.9 |
19.7 |
22.2 |
21.4 |
<0.05 |
|
Year 2013 |
||||||
|
Fertility rate (%) |
54.2 |
47.7 |
56.1 |
57.6 |
61.2 |
<0.01 |
|
Embryo mortality rate (%) |
7.81 |
7.53 |
6.44 |
11.16 |
6.12 |
0.38 |
|
Hatching rate (%) |
40.6 |
31.3 |
42.2 |
42.6 |
45.2 |
<0.05 |
|
Year 2014 |
||||||
|
Fertility rate (%) |
55.1 |
43.4 |
62.9 |
52.5 |
73.2 |
<0.01 |
|
Embryo mortality rate (%) |
3.93 |
2.63 |
4.33 |
3.94 |
4.83 |
0.77 |
|
Hatching rate (%) |
44.6 |
29.5 |
52.3 |
55.2 |
61.6 |
<0.01 |
|
Year 2015 |
||||||
|
Fertility rate (%) |
63.0 |
51.0 |
55.6 |
59.0 |
76.7 |
<0.01 |
|
Embryo mortality rate (%) |
10.8 |
13.8 |
11.6 |
10.6 |
7.13 |
0.14 |
|
Hatching rate (%) |
55.5 |
43.6 |
50.8 |
53.9 |
68.7 |
<0.01 |
|
Year 2016 |
||||||
|
Fertility rate (%) |
53.5 |
26.7 |
52.0 |
59.2 |
76.2 |
<0.01 |
|
Embryo mortality rate (%) |
7.52 |
11.4 |
5.66 |
4.81 |
8.20 |
0.33 |
|
Hatching rate (%) |
50.9 |
29.3 |
47.7 |
54.4 |
72.3 |
<0.01 |
|
abc Means within rows with different superscripts are different (P<0.05) |
||||||
Compared to other genotypes, Naked-neck chickens significantly had the lowest fertility rate with 42.9% (Figure 1). In the total population, the average of fertility rate was 51.4%. This rate is largely low compared to that recorded for the local Egyptian race Fayoumi which was indeed in the range of 80.6% and 94,0% (Abdellatif 1984).
|
ns: not significant, **: P<0.01, ***: p<0.001, Er: Ermine, Gs: Gray-shank, Cr:Crested, Nn: Naked-neck Figure 1. Fertility rate in four genotypes of the local Algerian chicken raised at the station |
The embryonic mortality rate was 9.50% in the total population. This parameter was not significantly different between the four genotypes (Figure 2). In the present study, the embryonic mortality rate can be explained by the power cuts which could last up to 10 hours during the incubation; thus, it is possible that the interval between the laying and the setting in incubation was too long.
 |
ns: not significant, Er: Ermine, Gs: Gray-shank, Cr: Crested, Nn: Naked-neck Figure 2. Embryo mortality rate in four genotypes of the local Algerian chicken raised at the station |
The hatching rate was significantly lowest in the Naked-neck chickens compared to the other genotypes (Figure 3). In the total population, the hatching rate was 41.9% and it remained low compared to values found in other studies: 87.6% in Egypt (Abdellatif 1984), between 66.9% and 83.5% in Congo Brazzaville (Akouango 2004), 87.6% in Côte d'Ivoire (Kouadio et al 2013).
 |
ns: not significant, ***: p<0.001, Er: Ermine, Gs: Gray-shank, Cr: Crested, Nn: Naked-neck Figure 3. Hatching rate in four genotypes of the local Algerian chicken raised at the station |
Growth represents in zootechnics all the changes in weight, shape and anatomical and biochemical composition of animals from conception to adulthood (Akouango 2004). Body weight is often the most common and informative measure of animal performance (Raji et al 2008).
The Table 4 shows that the genotype significantly (P ≤ 0.05) influenced the weight growth. At birth the weight of chicks from the four genotypes varied between 29.0± 0.5 g (Naked-neck genotype) and 30.8± 0.5 g (Ermine genotype). The chicks multiplied their weight 10 times, at least, after 8 weeks, reaching 530± 61 g in the Ermine phenotype, 433± 62 g in the Gray-shank phenotype, 448± 60 g in the Crested phenotype and 313± 51 g in the Naked-neck genotype.
In a similar study on the weight of local chicken at hatching, at 4 and 16 weeks, Mafeni (1995) reported the respective weights of 29.4 g and 881 g. Similarly, the weights at 4 and 8 weeks observed in the Fayoumi breed from Egypt were 171 g and 569 g respectively (Mérat and Bordas 1982). These performances are close to those observed in the present study at equal age.
|
Table 4. Estimation of the growth parameters in four genotypes of the local Algerian chicken raised at the station |
||||||||
|
Weight (g) |
Gray-shank |
Crested |
Naked-neck |
Ermine |
Total |
p |
||
|
1 day |
30.0ab |
29.7ab |
29.0a |
30.8b |
29.9 |
<0.05 * |
||
|
15 days |
75.7c |
74.4b |
57.9a |
90.3d |
74.6 |
<0.05 * |
||
|
4 weeks |
164ab |
164ab |
152a |
169b |
165 |
<0.05 * |
||
|
8 weeks |
433c |
448c |
313a |
530b |
458 |
<0.05 * |
||
|
abcd Means within rows with different superscripts are different (P<0.05) |
||||||||
The control of the performance of local chickens raised wandering in comparison with chickens raised in a controlled environment shows that all of the reproduction parameters are better in a controlled environment.
The chicken in rural areas, lays eggs at an average age of 6 to 6.75 months (Moula 2012, Mahammi 2015). According to the present study, the chickens at the experimental station started laying early (5.5 ± 1.7 months on average).
The average number of eggs laid in rural areas is 78 eggs / year (Mahammi 2015). In the controlled environment, this average annual egg production is much higher (230 eggs / year).
The weight of eggs laid in rural areas as reported by Moula (2012) is lower than that recorded in a controlled environment in this study (49.3g vs 50.6g) respectively.
The superiority of chickens raised in the station compared to those raised in rural areas is also observed in similar studies. For example, in Congo Brazzaville, there are 79.0 ± 10.0% fertility rate and 41.9 ± 3.5 g average weight of the egg in the station against 66.5 ± 13,0% and 35.3 ± 0.3 g in traditional breeding. Thus, in the extensive system, the average number of eggs per chicken per year varies between 34.0 and 45.1 with an average of 41.4 eggs; that is, half of the average spawning recorded in the semi-intensive system (Akouango et al 2004).
In general, the study of the zootechnical performances in type of semi- intensive breeding, of the local chicken, made it possible to highlight that these performances can be improved.
In Algeria, the commercial lines absorbed the poultry production market, which participated in the destruction of village poultry farming, which was very present before the 1980s. But consumer' food preferences for a quality product can help to safeguard local animal genetic diversity, as is the case in Europe (Moula 2012).
From the results of the present study, it emerges that there are significant differences between the 4 genotypes of chickens concerning the recorded zootechnical parameters. The latter were evaluated in a controlled environment where all the chickens benefit from the same breeding conditions (feeding, treatment, etc.). The Gs genotype showed the highest reproduction parameters (weight at start of lay 1.22 ± 0.11 kg, average egg weight 52.4 ± 4.6 g and number of eggs laid per month 21.7 ± 11.0) compared to other genotypes. Concerning the incubation parameters, the Nn genotype had the lowest values for fertility and hatching rates.
The significant difference observed between the genotypes studied seems to show that the latter differ genetically. These variations could be used in local chicken improvement programs by crossbreeding and / or selection.
The productivity level of local Algerian chickens, raised in experimental stations, is lower than the current industrial standard. However, its performance is interesting compared to the performance recorded in rural areas. This observation indicates a possibility of improving the zootechnical performance of the local chicken through the improvement of the breeding conditions and its feeding. It should be noted that for some breeders, productivity is a much less important concern than hardiness (Moula 2012). The local Algerian chicken meets the conditions to be the subject, in the future, of crossbreeding between local chicken in order to ameliorate some parameters like fertility and eggs for a better promotion of a quality production in poultry in Algeria.
The authors thank all the staff of the ITElv-Tlemcen station for their collaborations and for providing the data analyzed in this article.
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