Livestock Research for Rural Development 16 (8) 2004

Citation of this paper

Effect of dietary supplementation of energy and protein on production performance and egg quality of scavenging crossbred hens in rural areas under tropical conditions

M M Rashid***, M N Islam**, B C Roy***, K Jakobsen* and C Lauridsen*

*Department of Animal Nutrition and Physiology, Danish Institute of Agricultural Sciences, Research Centre Foulum,
8830 Tjele, Denmark
charlotte.lauridsen@agrsci.dk
**Bangladesh Livestock Research Institute, Savar, Dhaka, Bangladesh,
***Department of Livestock Services, Krishi Khamar Sharak, Farmgate, Dhaka, Bangladesh


Abstract

An on-farm experiment was conducted in rural areas of Bangladesh for a period of 16 weeks to assess the effect of supplementing two energy levels (2900 and 2500 kcal ME/kg diet), each at two protein levels (19 and 15%) with 60 g feed daily on production performance and egg quality of scavenging hens. In addition, the performance of hens under fully scavenging was compared to supplementary feed condition. Ninety crossbred Sonali (Rhode Island Red x Fayoumi) hens of 26 weeks were distributed among 18 farmers with 5 birds each, referring each bird to each of 5 groups: Group 1 (2900 kcal/kg and 19% CP); Group 2 (2900 kcal/kg and 15% CP); Group 3 (2500 kcal/kg and 19% CP); Group 4 (2500 kcal/kg and 15% CP), and Group 5 (fully scavenging without feed supplementation).

Feed supplementation significantly (P<0.01) improved body weight gain, egg production, egg weight, egg mass output and shell thickness compared to no feed supplementation. Hen-house egg production was 39.3, 35.9, 38.4, 35.2 and 24.3% for groups 1, 2, 3, 4 and 5, respectively.

Chemical analysis of the feed mixtures showed that the energy content of the high energy experimental diets was 5-7 % lower than stipulated, and expressed in terms of energy, the protein content was 183, 140, 194, and 144 g/10 MJ ME of Groups 1, 2, 3, and 4, respectively. The high protein level (Group 1 and 3) significantly (P<0.01) increased hen-house egg production, egg weight, egg mass, feed efficiency and shape index (P<0.05), but depressed shell thickness (P<0.05) compared to low protein level (Group 2 and 4). The birds fed the diet with the stipulated high energy levels (Group 1 and 2) had a significantly improved egg weight (P<0.01) and shape index (P<0.05) compared to birds in Groups 3 and 4.

Key words: egg quality, energy, hens, production, protein, scavenging


Introduction

Bangladesh has been endeavouring to boost up its chicken meat and egg production in order to meet the increasing "protein gap" in human food. The efforts have been made through improvement of the scavenging poultry production system, and introduction of exotic breeds and their crossbred chickens in this system. Identification of suitable breeds or breed combinations for sustainable production in this rural environment has been studied for many years (Rahman et al 1997; Rahman et al 1998; Akhtar-uz-Zaman 2002). In addition, several studies (Rahman et al 1997; Rahman et al 1998; Islam et al 1992; Akhtar-uz-Zaman 2002; Ali 2002) have shown that in order for the exotic breeds and their crossbreds in the scavenging production system to fully express their genetic potentiality, the birds need feed supplementation. Ali (2002) studied the effect of increasing amounts of feed supplementation (0, 30, 60, 120 g) of a diet containing 16% CP and 2700 kcal/kg energy on the production rate of scavenging crossbred hens, and found that 60 g of feed improved hen house egg production (32.8%) significantly compared to 30 g of feed and no feed supplementation with 21.2% and 20.2% hen house egg production, respectively. Except for the amount of feed, the level of protein and energy, being major components in a diet, influences the production performance of the hens. However, very little information is available on the influence of nutrient composition such as energy and protein concentration in supplementary diets on the production performance and egg quality of scavenging hens under rural conditions in Bangladesh. Thus, the present study was carried out to investigate the effect of varying energy and protein level in the supplementary diet (60 g/day) on production performance and egg quality of scavenging crossbred hens.


Materials and methods

The experiment was conducted for a period of 20 weeks among rural farmers located in the northern part of Bangladesh. The selection of farmers was based on equal economic status and on nearly uniform scavenging area for the birds.


Experimental birds and housing

A total of 90 Sonali (crossbred of ♂ Rhode Island Red x ♀ Fayoumi) hens aged 26 weeks were used for the present study. The hens were randomly distributed among 18 farmers with 5 birds each, referring one bird at random to each of 5 treatment groups. Vaccination against Newcastle disease was done before the distribution of birds.

A shelter made of bamboo divided into 5 coops of equal size (36 cm x 76 cm) was placed at each farmer's house to accommodate the five experimental birds. Each coop was equipped with a clay feeder and a plastic drinker. The climatic season (from November to February) covered by the experimental period was winter with temperature range from minimum 7 to13oC to maximum of 24 to 31oC, and with high humidity (75 to 86%). The birds were given a 4-week adaptation period with a reduced amount of layer diet to be gradually acquainted with the rural environment and  level of feed supplementation.


Dietary treatments

The four experimental diets consisted of two levels of energy (2900 and 2500 kcal ME/kg diet) and two levels of protein (19 and 15% CP). Group 1 was the combination of 2900 kcal ME and 19% CP, group 2 the combination of 2900 kcal ME and 15% CP, group 3 the combination of 2500 kcal ME and 19% CP, and group 4 the combination of 2500 kcal ME and 15% CP. In addition to the four groups, a fifth group was included, which was fully scavenging without feed supplementation.


Formulation of diets and chemical analysis

Experimental diets were based on ingredients as presented in Table 1. The proximate components of maize, soybean meal, rice polishings and wheat bran were analysed in accordance with AOAC (1990) at the Department of Livestock Services, Dhaka, Bangladesh. Calcium and phosphorus of the ingredients and of dicalcium phosphate and oyster shell were determined by atomic absorption and spectrophotometry, respectively (FAO 1980). Based on the given nutrient values of the presented feed items (Table 1), experimental diets were formulated to obtain the planned combinations of energy and protein level.


 Table 1.  Chemical composition of feed ingredients

Composition, %

Maize

Soybean meal

Rice polish

Wheat bran

Protein1 concentrate

Vegetable2 oil

Oyster shell

Dicalcium phosphate

Dry matter

87.02

87.09

89.61

88.60

7.00

-

99.46

99.77

Crude protein

9.01

39.87

15.65

14.36

60.00

-

-

-

Ether extract

3.29

1.85

24.18

2.46

10.00

100.00

-

-

Crude fibre

1.89

6.79

9.46

6.42

4.00

-

-

-

Ash

1.16

9.42

11.19

2.58

21.00

-

-

-

NFE3

71.67

29.16

29.11

62.77

-

-

-

-

Calcium

0.17

0.31

0.08

0.13

5.8

-

37.18

25.95

Total phosphorus

0.09

0.70

1.57

1.12

2.4

-

-

20.07

MEn4,kcal/kg

3278

2015

2837

1300

3230

8950

-

-

Amino acids5

Lysine

0.26

2.69

0.57

0.61

3.20

-

-

-

Metheonine

0.18

0.62

0.22

0.23

0.91

-

-

-

Cystine

0.18

0.66

0.10

0.32

1.05

-

-

-

1The nutrient composition of the protein concentrate was obtained from the declaration of the company (Manufactured for Jayson Agrovet Ltd. Bangladesh; By National by products Inc, USA).
2Assuming 100% ether extract in vegetable oil.
3
Nitrogen Free Extract (NFE) was calculated following the formula NFE (%)= 100% DM - (CP+EE+CF+Ash).
4The energy values of maize, soybean meal and rice polish were calculated from the proximate components according to Janssen (1989), and are shown as follows:
  
MEn for maize = 36.21 CP + 85.44 EE + 37.26 NFE
  
MEn for soybean meal = 37.5 CP + 46.39 EE + 14.9 NFE
   MEn for rice polish = 46.7 DM - 46.7 Ash 69.55 CP + 42.95 EE 81.95 CF.
   The energy values of wheat bran and vegetable oil were also obtained according to NRC (1994) and Nesheim et al (1979), respectively.
5Amino acid content of maize, soybean meal, rice polish and wheat bran was obtained according to NRC  (1994).


The ingredient composition of the four formulated experimental diets is shown in Table 2.


Table 2. Ingredient and nutrient composition of experimental diets

 

Group 1

Group 2

Group 3

Group 4

Stipulated energy, ME

2900 kcal/kg1

2500 kcal/kg2

Stipulated CP

19% CP

15% CP

19% CP

15% CP

Ingredients, %

 

 

 

 

Maize

58.00

67.50

49.00

57.00

Wheat bran

-

-

6.00

12.00

Rice polish

-

4.00

6.00

4.00

Soybean meal

22.50

11.00

26.00

15.50

Protein concentrate

8.00

7.00

4.50

2.50

Vegetable oil

3.30

1.50

-

-

Oyster shell

7.50

7.60

7.80

8.00

Dicalcium Phosphate

-

0.70

-

0.30

Rhodivet LS3

0.25

0.25

0.25

0.25

NaCl

0.45

0.45

0.45

0.45

Total

100.00

100.00

100.00

100.00

Nutrient composition4

Men, kcal/kg diet

2908

2908

2524

2531

Crude protein, %

19.00

15.29

19.28

15.16

Ether extract, %

6.42

5.59

4.14

3.67

Crude fibre, %

2.94

2.68

3.82

3.38

Lysine, %

1.01

0.72

1.04

0.74

Methionine, %

0.32

0.26

0.32

0.26

Cystine, %

0.34

0.27

0.33

0.27

Calcium, %

3.42

3.56

3.34

3.36

Total phosphorus, %

0.40

0.51

0.49

0.48

1 2900 kcal = 12.13 MJ.
2 2500 kcal = 10.46 MJ.

3 RhodivetL S (Rampart-Power Bangladesh Ltd. Gazipur, Bangladesh) was added at the rate of 0.25% in the mixed feed. Content per kg of premix: Vitamin A, 4,800,000 IU; vitamin D3, 1,000,000 IU; vitamin E, 8,000 mg; vitamin K3, 1,600 mg; vitamin B1, 0.600 mg; vitamin B2, 2,000 mg; vitamin B6, 1,600 mg; nicotinic acid, 12,000 mg; pantothenic acid, 4,000 mg; vitamin B12, 4 mg; folic acid, 200 mg; biotin, 20 mg; cobalt, 120 mg; copper, 2,400 mg; iron, 9,600 mg; iodine, 240 mg; manganese, 19,200 mg; zinc, 16,000 mg; selenium, 48 mg.
4Calculated according to information in Table 1.


The chemical analysis of the four mixed diets was performed at the Department of Animal Nutrition and Physiology, Danish Institute of Agricultural Sciences, Denmark. The following analyses were made: DM content by oven drying at 100oC for 20 hours, protein (N x 6.25) by a modified Kjeldahl method (KjellFoss 16200 Autoanalyser; Foss Electric A/S, Denmark). Ash was analysed according to AOAC (1990), and fat was extracted with diethyl ether after acid hydrolysis (Stoldt 1952). Starch and sugar were analysed according to Bach Knudsen et al (1993).


Feeding and management

Sixty grams of the experimental diets were divided into two portions and fed to the assigned birds. The first time, at 6.30 a.m., the birds were moved from the night shelter to the coops and offered 30 g feed and were kept confined until 10.00 a.m. The second time, at 4.00 p.m., the birds were collected again and offered the remaining 30 g of feed and transferred to the night shelter at 6.00 p.m. Between the confinement periods, the birds were allowed to scavenge. There was a continuous supply of drinking water in the coops, which were easily accessible during the day when the birds were scavenging. Birds of group 5 were released at 6.00 a.m. and housed again at 18.00 p.m., but had free access to their coops during the day. De-worming of the birds was performed every two months during the experimental period.


Data recording

Production performance and egg quality responses were obtained during a period of 16 weeks (from 31 to 46 weeks of age), and this period was divided into four 4-weekly periods.


Production parameters

Body weight of the birds was obtained at the beginning and end of the experiment (at 31 and 46 weeks of age, respectively). Total body weight gain was calculated by subtracting the initial body weight from the body weight obtained at the end of the study. Egg production and individual egg weight were obtained daily, and mortality was recorded as it occurred. Hen-house egg production (%), daily egg mass (g/hen/day), total egg number/hen and feed efficiency of supplemented diets in terms of egg mass production was also calculated.


Egg quality characteristics

Evaluation of egg quality was performed using the first egg from each hen laid during the fourth week of each period. The eggs were broken in the evening of the respective day of lay. Following this procedure, a total of 360 eggs, 90 in each period, were subjected to measurement of shell weight, shell thickness and internal qualities: albumen height, yolk height, yolk diameter, fresh yolk weight and yolk colour. Yolk weight was taken according to Chowdhury (1988). The albumen weight was determined by subtracting the yolk plus shell weight from the total egg weight. The shell weight was determined instantly after removing the shell membranes from the shell. Shell thickness and yolk colour were measured by a digital micrometer (Mitutoy, Tokyo, Japan) and the Roche Colour Fan (RYC, F. Hoffman-La Roche), respectively. Fifty eggs were randomly taken from the pooled eggs of each treatment group during the 4th period of the experiment irrespectively of farmers, to determine the shape index, which was calculated dividing the egg width by the egg length. Yolk index and haugh unit were calculated according to Wesley and Staldelman (1959), and Haugh (1937), respectively.


Statistical analysis

The following models were used:

A) Yijk= m + Di + Fj + Eijk
B) Yik = m + Di + Eik           
                 
C) Yijk= m + Ci + Pj + (CP)ij + Eijk

Where:
            Yijk (A)= the kth observation in ith diet and jth farmer,
            Yik (B)= the kth observation in ith diet, and
            Yijk (C)= the kth observation in ith energy level and jth protein level.

In the models:
             m = the general mean,
             Di = the effect of the ith diet group,
             Fj = the effect of the jth farmer,
             Ci = the effect of the ith energy level,
             Pj = the effect of the jth protein level,
             (CP)ij = the interaction effect between ith energy and jth protein level and
             Eijk or Eik = residual effect associating to Yijk or Yik.

Model A was used to compare the effect of dietary treatments on production performance and egg quality variables. Model B was considered for the shape index of eggs, and model C was used to evaluate the energy and protein levels in diets (excluding group 5). Descriptive analysis was performed using mean and standard deviation for each outcome variable. The analysis of all data was performed using General Linear Models (GLM) procedure  with SAS software (SAS 1999). Duncan's multiple-range test was used to compare treatment means (Steel and Torrie 1980).


Results

Table 3 shows the chemical analysis of the mixed diets used in this study. Protein levels in feed mixtures were consistent with the planned levels, although 1% higher for the stipulated low levels, and 5 to 8% higher for the stipulated high levels. However, energy content showed discrepancy with the expected level of diets; particularly in the high energy diets (groups 1 and 2), where the energy content was 5 to 7% lower than the planned level. When the protein content was expressed per 10 MJ energy, the feed mixtures contained 183, 140, 194, and 144 g protein/10 MJ for groups 1, 2, 3, and 4, respectively.


Table 3. Chemical analysis of the four supplementary diets

 

Group 1

Group 2

Group 3

Group 4

Stipulated energy, ME

2900 kcal/kg

2500 kcal/kg

Stipulated CP

19% CP

15% CP

19% CP

15% CP

Dry matter

91.96

91.95

91.65

91.90

Crude protein

20.57

16.09

20.34

15.81

Crude fat

5.19

5.49

3.95

4.65

Starch

33.96

40.12

32.11

37.76

Sugar

4.53

3.49

4.98

4.80

Ash

10.35

11.38

11.33

11.28

AMEn, MJ/kg feed1

11.23

11.53

10.47

10.96

AMEn, kcal/kg feed 2

2684

2756

2502

2619

1AMEn(MJ/kg feed)= 0.3431 * % fat +0.1551 * % protein + 0.1669 * % starch + 0.1301 * % sugar  (Fisher and McNab 1987).
2AMEn= Apparent metabolisable energy corrected to zero N-retention.


No mortality among the hens occurred, and no sign of (severe) disease was seen during the experimental period. Table 4 illustrates the production performance of hens. The hens under fully scavenging had significantly lower performance compared to the birds fed supplementary diets. The birds in groups 1 to 4 gained similar body weight during the study period. However, with regard to egg performance, hens of group 1 and 3 had the highest performance, which differed significantly from the performance of groups 2 and 4. With regard to feed conversion, group 1 showed a significantly better performance compared to all other groups, and group 3 had a significantly improved feed efficiency compared to groups 2 and 4.


Table 4.  Performance of experimental hens over a period of 31 to 46 weeks of age (N=18 birds/group). Hens were fed 60 g feed daily (group 1-4) or were fully scavenging (group 5). Values are meanSD1

 

Group 1

Group 2

Group 3

Group 4

Group 5

P-value

Body weight changes

 

 

 

 

 

 

Initial body weight, g

1382 63

1351 50

1373 48

1371 41

1369 51

0.467

Total BWG, g2

66.7a 24.7

57.8a 25.6

64.4a 27.1

58.9a 21.1

28.9b 15.7

<0.001

Egg performance

HHEP, %3

39.3a 4.26

35.9bc 4.62

38.4ab 4.47

35.2c 3.64

24.3d 7.43

<0. 001

Total egg number/hen

44.0a 4.78

40.2bc 5.17

43.0ab 5.00

39.4c 4.07

27.2 8.33

<0. 001

Egg weight, g

45.2a 2.61

44.8b 2.37

45.0ab 2.48

44.3c 2.44

43.8d 2.51

<0. 001

Egg mass, g/hen/day

17.8a 1.85

16.1bc 2.05

17.2ab 2.04

15.6c 1.57

11.0 d 3.27

<0. 001

FC, kg feed/kg egg4

3.41a 0.37

3.78c 0.45

3.54b 0.44

3.90c 0.41

-

<0. 001

1Means within a row without letters in common differ at P<0.05
2BWG=Body weight gain.
3HHEP=Hen-house egg production.
4FC=Feed conversion


Table 5 illustrates the egg quality characteristics of the groups during the experimental period. The shell thickness and yolk index of the eggs were significantly lower in fully scavenging birds compared to birds fed with supplementary diets, and other variables did not vary between the two groups of birds, although fully scavenging birds tended to produce eggs with higher yolk colour score. Shell percentage, shell thickness, albumen quality, yolk colour score and yolk weight did not differ significantly among groups 1 to 4. The birds in group 1 laid eggs with higher shape index number compared to the birds of groups 2, 3 or 4. The yolk index for groups 1, 3 and 4 did not differ, but group 2 showed depressed yolk index compared to groups 1 and 4.


Table 5 Egg quality characteristics of experimental hens over the period 31 to 46 weeks of age (N=18 birds/group). Hens were fed 60 g feed daily (group 1-4) or were fully scavenging (group 5). Values are meanSD1

 

Group1

Group 2

Group 3

Group 4

Group 5

P-value

Shell quality

Shell percentage

10.2 1.21

10.3 1.01

10.3 0.95

10.4 0.80

10.1 0.71

0.394

Shell thickness, mm

0.326a 0.019

0.331a 0.017

0.328a 0.018

0.332a 0.019

0.317b 0.018

<0.001

Shape index

0.775a 0.02

0.756b 0.03

0.756b 0.03

0.757b 0.03

0.757b 0.04

0.006

Albumen quality

Albumen height, mm

6.59 0.89

6.28 1.01

6.48 0.86

6.41 0.89

6.37 0.94

0.330

Haugh unit

85.4 5.45

83.3 6.44

84.8 5.31

84.3 5.5

84.1 5.82

0.262

Albumen weight, g    

27.0 1.87

27.2 1.50

26.9 1.70

27.3 1.96

26.8 1.44

0.35

Yolk quality

Yolk index

0.457a 0.02

0.448c 0.02

0.450ab 0.02

0.458a 0.02

0.441c 0.02

<0. 001

Yolk colour score

8.62 1.65

8.51 1.78

8.53 1.76

8.67 1.84

9.03 1.91

0.411

Yolk weight, g

13.6 1.23

13.4 0.96

13.5 1.28

13.1 1.37

13.5 1.30

0.122

1Means within a row without letters in common differ at P<0.05.


The analysed protein content per 10 MJ energy was similar in groups 2 and 4 (low protein level, 140 to 144 g protein/10 MJ), and in groups 1 and 3 (high protein level, 183 to 194 g protein/10 MJ), and Table 6 therefore shows the effect of the two dietary levels of protein on production performance and egg quality. Birds fed the high protein diets showed significantly improved production traits compared to birds fed the low protein diets except for the body weight gain, which was similar. High protein level in the diets significantly decreased shell thickness and conversely, increased shape index number, but other egg quality traits did not differ significantly between the two protein levels.


Table 6. Effect of high and low protein level in supplementary feed on production performance and egg quality characteristics of crossbred laying hens over the period 31 to 46 weeks of age (N=36 birds/group). Values are meanSD1

 

Stipulated protein level

P-value

19% CP

15% CP

Production performance

 

 

 

Total body weight gain, g

65.6 25.6

58.3 23.1

0.210

Hen-house egg production, %

38.8 4.33

35.5 4.12

0.002

Total egg number

43.5 4.85

39.8 4.61

0.002

Egg weight, g

45.1 2.55

44.6 2.41

<0.001

Egg mass, g/hen/day

17.5 1.94

15.8 1.82

<0.001

Feed efficiency, kg feed/kg egg

3.48 0.40

3.84 0.43

<0.001

Egg quality

 

 

 

Shell percentage

10.3 1.09

10.4 0.91

0.40

Shell thickness, mm

0.327 0.018

0.331 0.018

0.035

Shape index

0.766 0.028

0.756 0.03

0.020

Albumen height, mm

6.53 0.88

6.34 0.95

0.07

Haugh unit

85.1 5.37

83.8 5.99

0.057

Albumen weight, g

26.9 1.78

27.2 1.74

0.17

Yolk index

0.454 0.02

0.453 0.02

0.76

Yolk colour score

8.58 1.70

8.59 1.81

0.94

Yolk weight, g

13.5 1.25

13.3 1.19

0.051

1As no significant interactions between energy and protein were obtained in this study, results of this parameter are not shown.


By analysis of the effect of the stipulated dietary energy level on the performance and egg quality, only egg weight (45.1 g vs. 44.6 g, P<0.001) and shape index (0.766 vs. 0.756, P=0.027) was higher in birds fed the stipulated 2900 kcal/kg diet than in birds fed the 2500 kcal/kg diet, respectively.


Discussion

The calculated energy concentration (AMEn) obtained by chemical analysis of the nutrient content (Table 3) in diets 1 and 2 (average 2720 kcal) was lower than the stipulated (2900 kcal), and the calculated (2908 kcal, Table 2) energy content. Improper mixing of the oil with other ingredients may be the reason for this discrepancy. Higher presence of soybean meal in samples due to bigger particle size could be the reason for the generally slightly higher protein in the analysed feed samples (Table 3).

The present results clearly showed that feed supplementation significantly improved production performance of hens compared to without feed supplementation. The average egg production of the supplemented feed groups and the fully scavenging group was 37.2 and 24.3%, respectively, and this difference was consistent with the results of Ali (2002). In the latter study, increasing amounts of feed supplementation (0, 30, 60, 120 g) of a diet containing 16% CP and 2700 kcal/kg energy were studied for similar genotype hens as used in the present study. Ali (2002) concluded that 60 g of feed improved egg production (32.8%) significantly compared to 30 g of feed and no feed supplementation with 21.2% and 20.2%, respectively, and therefore it was decided to use an amount of 60 g of feed in the present study. The slightly higher egg production obtained in the present study could be due to the variation of scavenging feed availability in the locality, as well as to the difference in age of the birds.

Previous studies have also shown beneficial effects of feed supplementation with regard to performance of birds. Dessie and Ogle (1997), Demeke (1996), Smith (2001) and Sonaiya et al (2002) reported significantly increased egg production by indigenous birds provided different amounts of supplementary feed, when compared with the fully scavenging indigenous birds. In addition, positive effects of feed supplementation on egg weight were observed in previous research (Ali 2002; Akhtar-uz-Zaman 2002; Dessie and Ogle 1997). Akhtar-uz-Zaman (2002) reported that egg quality did not vary among three levels (15, 30 and 45 g) of feed supplementation, which complied with the present study as only minor influence of feed supplementation was observed with regard to egg quality. The reduced shell thickness in full scavenging group may be due to deficiency of Ca and P in scavenged food, which is corroborated by the crop content analysis of scavenging laying hens collected from the same area (Rashid 2003).

As the feed analysis showed no difference between stipulated high and low dietary energy levels, it was not surprising to find no effect of dietary energy on measured performance and egg quality in the present study. It was, therefore, not possible to conclude if energy or protein was the major limiting nutrient in the diet for the scavenging birds. However, analysing crop contents of scavenging laying hens from the same area in another trial, Rashid (2003) reported that scavenging feed resources are found to be much lower in protein (11.4%) and slightly lower in energy (2776 kcal ME/kg DM) relative to the requirements according to NRC (1994). On the contrary, Dessie and Ogle (1997) reported from a study in Ethiopia that indigenous hens receiving daily allowances of 2.49 g CP and 111 kcal, 10.1 g CP and 55 kcal, and 10.1 g CP and 157 kcal per day as supplementation,  produced eggs at a rate of 25, 20 and 30%, respectively, and it was concluded that energy rather than protein was the major limiting nutrient in the diet of scavenging hens, although high protein consumption significantly increased the egg weight. Baset et al (2000) obtained no significant difference in weight gain and egg production (39.3% vs. 42.1%) between two groups of Fayoumi hens in rural areas of Bangladesh, which were offered 122 kcal and 8.7 g CP through 51 g diet/day, and 155 kcal and 11.1 g CP through 65 g diet/day.

The present study showed that birds receiving 19% CP laid 3.44% more eggs compared to birds receiving 15% CP (Table 6), and that increasing the dietary protein level also improved the egg weight and the feed conversion of the birds. In other words, hens on low protein diets could not manage to find enough protein from scavenging sources to perform equally to hens on high protein diets receiving 2.4 g more protein daily. Thus, from the overall results, it may be concluded that high protein level (190 g/10 MJ) in a supplementary diet could be recommended for a viable production of crossbred hens under rural conditions. However, since protein-rich feeds are expensive, future research should focus on the possibility of using cheap conventional and non-conventional protein-rich feed resources as feed supplement for scavenging chicken in rural areas in developing countries.


Acknowledgements

The study was financially supported by the Danish International Development Agency (DANIDA) through the Network for Smallholder Poultry Development with a MSc. grant for the first author. The authors wish to express their gratitude to Dr. Guosheg Su (Department of Animal Breeding and Genetics, Danish Institute of Agricultural Sciences) for his help regarding statistical analysis of data.


References

Akhtar-uz-Zaman M 2002 Egg production performance of different breed/breed combinations of chicken in semi-scavenging system under PLDP. M. Sc. Thesis, The Royal Veterinary and Agricultural University, Denmark.

Ali M S 2002 Study on the effect of feed supplementation to laying hen under the rural condition of Bangladesh. M. Sc. Thesis, The Royal Veterinary and Agricultural University, Denmark, pp. 50.

AOAC 1990 Official Methods of Analysis. 15th edition Association of Official Analytical Chemists. Washington DC.

Baset M A, Bhuiyan M M and Islam M M 2000 Performance of Fayoumi chicken under different rearing systems in Sylhet District. Bangladesh Journal of Animal Science, 29(1-2): 105-110.

Bach Knudsen K E, Jensen B B and Hansen I 1993 Digestion of polysaccharides and other major components in small and large intestine of pigs fed on diets consisting of oat fractions rich in β-D-glucan. British Journal of Nutrition, 70: 537-556.

Chowdhury S D 1988 Method of partitioning egg components. Bangladesh Journal of Animal Science, 17: 93-97.

Demeke S 1996 Study on egg production of White Leghorn under intensive, semi-intensive and rural household conditions in Ethiopia. Livestock Research for Rural Development, 8(2) http://www.cipav.org.co/lrrd/lrrd8/2/ethiop1.htm

Dessie T and Ogle B 1997 Effect of maize (Zea mays) and noug (Guizotia abyssinica) cake supplementation on egg production performance of local birds under scavenging conditions in the Central Highlands of Ethiopia. Proceedings INFPD Workshop, M'Bour, Sénégal, December 9-13, 1997. pp 155-168.

FAO 1980 Soils Bulletin 38/1. Soil and plant testing analysis, FAO, Rome, pp 230.

Fisher C and McNab J M 1987 Techniques for determining the ME content of poultry feeds. In: W. Haresign and D.J.A. Cole, (Editors), Recent advances in Animal Nutrition-1987. Butterworths, London. pp 3-17.

Haugh R R 1937 The Haugh Unit for measuring egg quality. U.S. Egg Poultry Magazine, 43: 552-553 and 572-573.

Islam M K, Hussain M A, Haque M F and Paul D C 1992 Performance of Fayoumi poultry breed with supplemental ration under farmer's management. Proceedings of the 4th National Conference, 1992, held in Dhaka, Bangladesh, pp 20-29.

Janssen W M M A ed. 1989 European Table of Energy Values for Poultry Feedstuffs. 3rd edition. Beekbergen, Netherlands: Spelderholt Centre for Poultry Research and Information Services.

NRC 1994 Nutrient requirement of poultry. Ninth revised edition, National Academy Press, Washington DC, USA, pp 61-79.

Nesheim M C, Austic R E and Card L E 1979 Poultry Production. 12th edition. Philadelphia, USA, pp 220-221.

Rahman R, Sorensen P, Jensen H A and Dolberg F 1997 Exotic hens under semi scavenging condition in Bangladesh. Livestock Research for Rural Development. 9(3): http://www.cipav.org.co/lrrd/lrrd9/3/bang931.htm

Rahman M, Islam M N, Sarker N R and Islam M M 1998 Effect of supplementary feeding on production performance of RIR, Fayoumi and their crossbred chicken in Rural Bangladesh. Bangladesh Journal of Livestock Research, 1: 184-193.

Rashid M M 2003 Nutritional status of scavenging chickens with special emphasis on energy and protein supplementation under rural conditions in Bangladesh. M. Sc. Thesis, The Royal Veterinary and Agricultural University, Denmark.

SAS Institute 1999 SAS Statistics Users Guide, Statistical Analysis System, 5th edition, 8.2 version, (Carry, NC, SAS Institute Inc.).

Smith A J 2001 Poultry, 2nd edition, Macmillan Education Ltd, London and Oxford. pp 140, 201-202.

Sonaiya E B, Olukosi O A, Obi O and Ajuwon K M 2002 Vaccination and scavengable feed resource amassment for village poultry; Proceedings 3rd Scientific Coordination Meeting of the Joint FAO/IAEA Coordinated Research Program on assessment of the effective of vaccination against poultry production in Africa. Quatre Bornes, Mauritius: www.iaea.org/programmes/nafa/d3/mtc/sonaiya-doc.pdf

Steel R G D and Torrie J H 1980 Principles and Procedures of Statistics: A Biometrical Approach. 2nd edition, McGraw-Hill Book Company, New York, NY.

Stoldt W 1952 Vorslag zur Vereinheitlichung der Fettbestimmung in Lebensmitteln (Suggestions to standardize the determination of fat in foodstuffs). Fette, Seifen, Anstrichmittel, 54: 206-207.

Wesley R L and Stadelman W J 1959 Measurement of interior egg quality. Poultry Science, 38: 479-481.


Received 3 June 2004; Accepted 26 June 2004

Go to top