Livestock Research for Rural Development 34 (7) 2022 LRRD Search LRRD Misssion Guide for preparation of papers LRRD Newsletter

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Effect of replacing essential amino acids and soybean seed with meat and bone meal on feed intake, body weight change and quality of eggs in exotic chickens

Berhane Mekete Bogale and Tesfaye Engida D

Department of Animal Sciences, Guder Mamo Mezemir Campus, School of Agriculture, Ambo University, P O Box 19, Ambo, Ethiopia
tesfaye.engida@yahoo.com

Abstract

The research work was conducted to evaluate the effect of replacing essential amino acids and soybean seed with meat and bone meal on feed intake, body weight change and quality of egg. Ninety Bovans Brown layers having 28 weeks of age and similar body weight were randomly allocated to three treatments using a complete randomized design. Each treatment had two replicates comprising of 15 layers per replicate. The dietary treatments were: T1 (control chickens) were fed purchased standard commercial layer ration, T2 were fed formulated layer ration with the inclusion of essential amino acids and soybean seed, while T3 were fed formulated layer ration with the inclusion of 10% meat and bone meal. The chickens were fed weighted feed and freely accessed to water for 90 days. Data on dry matter intake, body weight change, and internal and external egg quality parameters were recorded. Data were analysed using SAS software packages, and Turkey's HSD multiple comparison techniques was used for means separation. The mean dry matter intake (gm/h/d) was higher (p<0.01) in T3 (106.75) and T1 (105.24) than T2 (102.56). The higher (p<0.05) mean body weight change (gm/hen) and body weight gain (gm/hen/day) were recorded in T3 than T2, but was not differ (p>0.05) with the control. The external egg quality evaluation revealed that the higher mean egg length (mm) was recorded (p<0.01) in T3 (58.73) than T2 (56.15). On the other hand, the mean shell thickness (mm) was higher (p<0.05) in T1 (0.30) than both T2 (0.27) and T3 (0.27). Concerning internal quality of egg, the mean albumen height (mm) and yolk weight (gm) were higher P<0.05) in T3 than both T1 and T2. Besides, T3 had the highest yolk diameter (41.34) and Haugh unit (84.02) than T2. The mean yolk color was higher (p<0.001) in T1 (5.94) than both T2 (1.06) and T3 (1.19). Therefore, it is concluded that an alternative layer ration could be formulated with the inclusion of 10% meat and bone meal without using essential amino acids and soybean seed.

Keywords: external egg quality, feed, formulated feed, internal egg quality, laying hens


Introduction

Poultry industry is the continuously growing agricultural sector in many parts of the world. The increasing human population, greater purchasing power and urbanization have been strong drivers of growth (FAO 2019). The potential contribution of poultry industry to improve food security, nutrition and meat consumption is huge (Shapiro et al 2015). Chicken production plays a key role in the livelihoods of the rural people, particularly to the developing countries, that is being an immediate income source and by improving the nutritional status of the rural households (Tadele et al 2018). As the demand for poultry products is increasing in developing countries, egg production should be increased in quantity and quality to meet the public demands from the commercial laying hen industry (Macit et al 2021).

Ethiopia has high chicken population, which is estimated about 57 million (CSA 2020). However, the consumption of chicken meat and egg in the country is very low compared to other countries. Generally, the demand of animal source foods is not yet met in Ethiopia. Currently, poultry industry is immensely supplying animal proteins, but it is highly constrained by the availability, quality, and cost of feed ingredients (Shapiro et al 2015; Ugwuowo et al 2019). Some feed ingredients, particularly those sources of the crude protein are very expensive and sometimes inaccessible to the producers (FAO 2018). Feed is the most important factor which determines the success of poultry business and represents 70 percent of the total production costs (Ugwuowo et al 2019)

The feed industry in developing countries is faced with a lot of challenges with regard to the availability of conventional feed ingredients and also the ability to produce high-quality feeds in a cost-effective manner. So, there is a need to exploit cheaper non-conventional feed ingredients to replace expensive conventional feedstuffs for animal production and at the same time reduce food-feed competition in the future. In view of this, the interests of researchers have been increased to search novel feed resources to replace the expensive conventional energy and protein feedstuffs in livestock and poultry diets (Ogbuewu and Mbajiorgu 2019).

The prices of different commercial formulated poultry rations have frequently increased and were not economical for small and medium-level poultry producers in Ethiopia and most other countries. As the demand for poultry products is increasing in developing countries, it has a profound effect on the demand for feed and raw materials (Ravindran 2013). On the other hand, locally available feed sources have the potential to fill the gap when it is formulated with nutritionally balanced diet (Geleta 2020). It is very important that there is a need to improve the scientific knowledge for utilizing low-cost locally available agro-industrial by-products in poultry feed to reduce the feed cost (Thirumalaisamy et al 2016). Locally available feed sources have the potential to cover the gap when formulated with a cost-effective and nutritionally balanced diet (Geleta 2020).

In Ethiopia, seasonality, shortage and prices of feed ingredients are key challenges for sustainable and affordable delivery of commercial compound feeds (Bediye et al 2018). Meat and bone meal (MBM) is an important feed stuffs in poultry nutrition, due to its high protein content and relatively competitive cost. It has the crude protein (CP) content of 49.5 to 59.4% with a well-balanced amino acids profile including the limiting amino acids of methionine and cysteine for poultry (Hicks and Verbeek 2016). MBM is also an excellent dietary source for phosphorus and calcium and an alternative feed resource for poultry and the inclusion of dietary MBM to the layer diet was found to increase egg shell quality (Sell and Jeffrey 1996). Likewise, Soybean (Glycine max L.) is an excellent source of protein for animals and humans because of the high sulfur amino acid content (NRC 1994), and has an average CP content of about 37-38% and 20% fat on a dry matter basis (Nahashon and Kilonzo-Nthenge 2013).

Feeding of formulated layer rations to exotic chickens by replacing expensive feed ingredients of essential amino acids (EAA) and soybean seed with innovative approaches and relatively less expensive and locally available feed ingredients of MBM is highly important to reduce the feed cost of layer rations, thereby contribute to small and medium poultry farmers to achieve higher profit. However, there are very little or no research works conducted in replacing EAA and soybean seed with MBM in layer rations. Hence, the present research work was undertaken to evaluate the effect of replacing soya bean seed and EAA with MBM on body weight change and quality of egg in exotic chickens.


Materials and methods

Description of the study area

The experiment was conducted in Ambo University Poultry Farm found in Ambo town, West Shewa Zone, Oromia Regional State, Ethiopia. Ambo town is located 114 kms West of Addis Ababa, at latitude of 80.59’N and longitude of 37050’E (Ogato 2013). The mean annual temperature and rainfall were 18.64oC and 968.74 mm, respectively. The Ambo town has an altitude 2101 meters above sea level (Ogato 2013).

Experimental feed ingredients, feed preparation, and formulated rations

The feed ingredients used to formulate experimental layer rations were maize, wheat short, niger seed cake, MBM, soybean grains, EAA (methionine, lysine, and dicalcium phosphate), limestone, vitamin premix, and salt (Table 1). This feeding trial was involving three forms of layer feeds which were, Treatment 1 (T1) considered as control feed which was standard commercial compound layer ration purchased from feed processing factory. Whereas, treatment 2 (T2) ration was experimental formulated layer feed with the inclusion of EAA (EAA) and roasted soybean seeds along with other feed ingredients. Treatment 3 (T3) ration was formulated layer feed by increasing the level of MBM from 5% (which was in T2) to 10% to satisfy the EAA, phosphorus, and calcium requirements.

Before the formulation of the layer ration of T2, soybean seeds were roasted/fried on the metal pan using wooden materials as a source of heat energy to inactivate anti-nutritional factors such as trypsin inhibitor. Maize, niger seed cake, soybean grains, and salt were weighed based on their proportions and ground with a feed mill to pass through a 5mm sieve size. The grounded feed ingredients along with other non-grounded feed ingredients were formulated accordingly and thoroughly mixed using the mixer machine at Ambo University Feed Processing unit (Table 1). All feeds were formulated based on international recommendation to satisfying the birds major nutrient requirements and had similar iso-nitrogenous content of 16 to 17.5% crude protein (CP) and iso-caloric content of 2800 to 2900 Kcal metabolizable energy (ME) per Kg of dry matter (NRC 1994).

Table 1. The proportion (%) of feed ingredients used in the formulation of the treatment layer rations

No

Feed ingredients

T2

T3

1

Maize grain

54

56

2

Wheat short

8

8

3

Niger seed cake

18

21.4

4

Soybean grains (Fried)

10.1

-

5

Meat and bone meal

5

10

6

Methionine

0.1

-

7

Lysine

0.1

-

8

Di-calcium phosphate

0.1

-

9

Limestone

4

4

10

Vitamin premix

0.25

0.25

11

Salt

0.35

0.35

Total

100

100

T2=Treatment two; formulated layer ration with the inclusion of essential amino acids and roasted soybean, T3=Treatment three, formulated layer ration with increasing the level of meat and bone meal from 5% to 10%
Experimental design and dietary treatments

A total of ninety Bovans Browns layers chickens having similar age (28 weeks) and body weight (1.57+0.003 kg) were selected from Ambo University poultry farm and randomly allocated to three dietary treatments in a complete randomized design. Each treatment had two replicates comprising of 15 layers per replication, and 30 layers per treatment. Chickens of T1 were fed commercial purchased feed, whereas, chickens of T2 were fed EAA and soybean based formulated ration and chickens of T3 were fed MBM based formulated ration (Table 1). The layers were adapted to experimental diets for 10 days before the commencement of actual data collection. The feeding trial was conducted for 90 days.

Management of chickens

The layers were kept in a deep litter house, partitioned into 6 pens with wire mesh and a hardboard partition. The floor of the pens was covered with clean disinfected tef (Eragrostis tef) straw at a depth of 10 cm as litter material and the pens were equipped with clean and disinfected feeders, waterers and laying nests. The wet litter in the floor or laying nests or both was changed with dry, disinfected and clean teff straw whenever required. The layers chicken were fed the weighted amount of feed with 10% refusal twice per day both in the morning at 7:30 AM and in the afternoon at 2:30 PM. Clean tap water was available all the time. During night time, electric power was used as a source of light for additional 4 hours of light. Similar managerial and bio-security protocol was employed for all chickens during the experimental period.

Collection of samples and feed chemical analysis

Representative feed samples from each feed offered per pen were daily collected during the entire experimental period. Respective pooled offered feed samples per treatment were analyzed at Bishoftu National Veterinary Institute. Crud protein, dry matter (DM), ether extract (EE), crude fiber (CF) and total ash (Ash), calcium (Ca) and phosphorus (P) contents were analyzed and determined by the method of AOAC (1990). The ME content was calculated by indirect method as described by Wiseman (1987) as follows;

ME (Kcal/Kg DM) = 3951+54.4 EE – 88.7 CF – 40.8 Ash

Where, ME = Metabolizable energy, kcal= kilo calorie, kg= kilogram, DM=Dry matter, EE=Ether extract, CF= Crude fiber

Variable measured during the study period
Feed intake and body weight change of chickens

The amount of feed offered per replicate was recorded daily and the feed refusal was collected and weighed from each replicate in the next morning before offering the feed. The amount of feed consumed was determined by deducting feed refusal from feed offered. The DM intake for each replication was then calculated by multiplying the feed intake by the respective analyzed DM percentage of each treatment ration.

The hens were weighed individually at the start and end of the experimental period with an empty stomach in the morning hours using the analytical sensitive balance. Body weight change was calculated as the difference between the final and initial body weight of chickens in each treatment. Average daily gain (gm/d) per chicken was calculated as body weight change in each treatment divided by the number of feeding days. The formulas are given below:

Body weight change (gm /hen) = Final body weight - Initial body weight of chickens

Egg quality parameters

Egg quality evaluation was done for both external and internal quality of eggs. Hence, measurements of external and internal parts of each egg were taken from six freshly laid and randomly selected eggs per replication at fortnightly interval.

External egg quality

The external egg quality was determined by measuring the egg and shell weights, egg length and width, and shell thickness. The egg and shell weight was taken using electrical digital sensitive balance, the width and length of egg measured using electronic digital caliper, while egg shell thickness was measured using micrometer screw gauge from three regions (air cell, equator and sharp end) and the average value was taken. Egg shape index was also calculated using the following formula;

Internal egg quality

The internal egg quality was determined after breaking the eggs on a clean, smooth leveled surface and separating each of the egg components. Albumen and yolk weights measurement were taken using electrical digital sensitive balance after carefully separated. The albumen and yolk height was measured with tripod micrometer. Yolk diameter was measured using a steal vernier caliper. Yolk color measurement was taken after thoroughly mixed the whole yolk and comparing the color of mixed yolk by visual comparison to color strips of Roche fan, which consist 1-15 strips ranging from pale to deep reddish orange color. Egg yolk index was computed using the formula developed by Panda (1996) and Haugh unit score was calculated using the formula suggested by Haugh (1937) as follows:

Where H is albumen height (mm) and W is weight of egg (g)

Data analysis

All the collected data were subjected to one-way ANOVA using the Statistical analysis systems software packages (SAS 2009). Differences among treatment means were separated using LSD. p<0.05 was considered statistically significant. The following statistical model was used;

Yij = μ + Ti + eij Where, Yij = represents the jth observation in the ith treatment (response variable such as feed intake, body weight and egg quality) μ = overall mean, Ti = ith treatment effect (feeds) (i= 1, 2, 3), eij = random error


Results and discussion

Feed chemical analysis

The results of the chemical analysis of different feed ingredients used in ration formulation and the nutritional composition of the layer rations for each treatment have been presented in Table 2. In the formulated layer rations, the CP values of the treatment layer rations ranged from 16.4% (T3) to 17% (T2), which were in the acceptable range. The CF content of layer rations was the highest in T2 while it was the lowest in T1. The ME content of the treatment layer rations was between 2820 (T3) and 2890 (T2).

Table 2. The chemical composition (%) of different feed ingredients and layer rations

Feed ingredients and treatment diets

DM

CP

EE

CF

ASH

Ca

P

ME Kcal/kg
of feed

Feed ingredients

Maize grain

92.5

8.52

4.2

4.1

5.8

0.1

0.3

3480

Wheat short

90.5

15.4

4.6

5.85

4.93

0.2

0.3

2640

Niger seed cake

92.1

31.9

6.5

15.5

7.1

0.5

0.3

2460

Soybean (Fried)

93.2

40.9

8.5

14.2

6.92

0.3

0.5

2560

Soybean (Non fried)

92.4

41.9

7.5

17.7

6.48

0.4

0.5

2650

Meat and bone meal

93

47.3

8.4

6.5

10.7

0.7

0.9

2250

Treatment diets

T1

92

16.7

5.4

5.22

10.2

2.2

0.3

2850

T2

90.6

17

5.6

7.17

8.53

2.5

0.4

2890

T3

90.8

16.4

5.3

6.4

8.77

3.3

0.4

2820

DM = Dry Matter, CP = Crude Protein, EE= Ether Extract, CF= Crude Fiber, Ca= Calcium and P=Phosphorous, ME= Metabolized energy, T1= Control, layer ration T2= Treatment two, T3= Treatment three
Feed intake and body weight change of chickens

The values of feed intake and body weight of layer hens fed different layer ration have been summarized in Table 3. The mean daily dry matter intake was higher (p<0.01) in hens fed with T3. The final body weight was higher (p<0.05) in T1 and T3 than T2. The mean body weight change per chicken was higher (p<0.05) in hens fed with T3 than those hens fed with T2 and there was no difference between T1 and T3. Similarly, the mean body weight gain was higher (p<0.05) in hens fed with T3 than those hens fed with T2 and no difference (p>0.05) between T1 and T3. However, the mean body weight change and mean daily body weight gain of T1 was similar (p> 0.05) with T2 (Table 3). The replacement of EAA and soybean with MBM increased dry matter intake, body weight change and daily weight gain in T3. The increment of dry matter intake in treatment T3 was in agreement with the finding of Hussein et al (2015) who reported that feed intake was increased at a higher level of replacement (75% and 100%) of soybean meal with processed kidney bean in layer rations. The possible reasons for significantly higher dry matter intake, body weight change and daily gain in T3 ration could be due to the higher protein and mineral content of MBM. Hicks and Verbeek (2016) reported that MBM has high contents of crude protein ranging from 49.5 to 59.4% and the CF content was less (1% to 5.13%) with a well-balanced amino acid profile including the limiting amino acids (methionine and cysteine) in poultry rations. Similarly, Miles and Jacob (2011) also stated that MBM has high calcium, available phosphorus, and lysine contents, and can be included in layer ration up to 10%. Thus, the higher nutrient contents of T3 ration might have contributed to higher dry matter intake, body weight change and daily body weight gain.

Table 3. The mean feed intake and body weight change of layer hens fed different layer ration

Variables

T1

T2

T3

SEM

p-value

Dry matter intake (g/hen/d)

105.24a

102.56b

106.75a

0.437

0.002

Initial body weight (kg/hen)

1.58

1.57

1.55

0.009

0.433

Final body weight (kg/hen)

1.74a

1.64b

1.73a

0.018

0.049

Body weight change (gm/hen)

160ab

74.67b

181.67a

20.10

0.470

Body weight gain (gm/hen/day)

1.78ab

0.83b

2.02a

0.223

0.470

ab Means in the same row without common letter are different at p<0.05. T1=control layer ration, T2=Treatment two, T3=Treatment three

The lowest feed intake, final body weight and body weight change recorded in T2 ration was similar to the findings of Varastegani and Dahlann (2014) who reported that a higher level of CF in the layer's ration affected the normal feed consumption. These could be due to its highest CF content of fried soybean seed in the T2 ration. Melesse (2020) also stated that dietary crude fiber could be a possible attributer for lower feed intake and has been considered as diluents of the diets and has anti-nutritional factor. As the feed consumption is affected, the body weight change and daily weight gain of chickens was also affected as they have direct relationships. Hence, fiber is viewed negatively as it decreases the efficiency of feed utilization, and intern declines the body weight change and daily weight gain of chickens as well as chicken growth. Liener (1994) and Pitala et al (2016) stated that raw soybeans are known to contain anti-nutritional factors like trypsin that interfere with the absorption of protein, depressing feed intake, growth rate and reduce the overall performance of poultry. So, before its incorporation, soybean must be pretreated either by modern or traditional techniques to reduce anti-nutritional factors. But, in the current study, the level of roasting might not be sufficient to reduce the impact of anti-nutritional factors as it was roasted in the traditional way using wooden materials on the metal container. As a result, the negative effect of anti-nutritional factors might have been reflected in reducing the feed intake, the body weight change and daily weight gain of chickens fed on the soybean based ration.

External egg quality

The values of external quality of eggs have been summarized in Table 4. The external egg quality evaluation revealed that there were differences in egg length, shell thickness and egg shape index among the treatments. The mean egg length was higher (p<0.01) in T3 than T2 which is related with the egg weight. The mean shell thickness was higher (p<0.05) in T1 than both T2 and T3. The egg shape index (%) was higher (p<0.05) in T2 and there was no difference between T1 and T3 in egg shape index. This result was in agreement with the report of Kowalska et al (2021) who reported that the egg shape index was higher in soybean supplemented layer feed than non-supplemented one and this indicated that the shape index may be affected by the source of protein in layer hen. However, shell weight, egg width and egg weight was similar (p>0.05) among the treatment.

Table 4. The mean external eggs quality for hens fed treatment layer rations 

Parameters

T1

T2

T3

SEM

p-value

Egg weight (gm)

59.32

59.10

61.58

0.728

0.312

Egg length (mm)

57.30ab

56.15b

58.73a

0.33

0.004

Egg width (mm)

43.39

43.58

44.29

0.221

0.222

Shell weight (gm)

7.51

7.36

7.19

0.089

0.350

Shell thickness

0.30a

0.27b

0.27b

0.006

0.044

Egg shape index (%)

75.78b

77.64a

75.44b

0.376

0.032

ab Means in the same row without common letter are different at p<0.05.
T1 = Control layer ration, T2 = Treatment two, T3= Treatment three

Internal eggs quality

The values of internal eggs quality have been presented in Table 5. The internal egg quality evaluation reveled that there were significant differences in albumen height, yolk weight, yolk diameter, yolk color and Haugh unit. The mean albumen height, Haugh unit and yolk weight were higher (p<0.05) in T3 than both treatments. The highest albumen height and Haugh unit value were similar to Çatlı et al (2012) finding who reported that layer hen fed with 12% MBM in their diet had the highest albumen height and Haugh unit value. Similarly, Bozkurt et al (2004) also reported that the highest value of Haugh unit was recorded from the egg that hens fed on 6% of MBM in their ration than other dietary treatments. The mean yolk color were higher (p <0.01) in T1 than both T2 and T3. However, there were no difference (p>0.05) among the treatment groups in albumen weight, yolk height and yolk index. Generally, there were no negative effect with regard to egg length, egg shape index, yolk diameter and Haugh unit values in the layer ration formulated with the inclusion of 10% MBM as it had similar findings with the control ration.

Table 5. The mean internal eggs quality for hens fed treatment layer rations

Parameters

T1

T2

T3

SEM

p-values

Albumen weight (gm)

35.94

35.70

37.04

0.555

0.585

Albumen height (mm)

6.44b

6.25b

7.25a

0.162

0.024

Yolk weight (gm)

15.88b

16.04b

17.36a

0.241

0.020

Yolk height (mm)

14.69

14.63

14.96

0.179

0.723

Yolk diameter (mm)

40.78ab

39.87b

41.34a

0.255

0.028

Yolk color

5.94a

1.06b

1.19b

0.340

0.000

Yolk index (%)

36.15

36.65

36.21

0.463

0.897

Haugh unit

79.52ab

78.45b

84.02a

0.111

0.029

ab Means in the same row without common letter are different at p<0.05.
T1 = Control layer ration, T2 = Treatment two, T3= Treatment three


Conclusion


Acknowledgements

The authors sincerely acknowledge Ambo University for supporting and facilitating the research activities.


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