Evaluation of shrimp head meal and cassava leaf meal as protein sources in diets for Luong Phuong Hoa laying hens

Le Diep Long Bien and Pham Cong Thieu

National Institute of Animal Husbandry, Hanoi, Vietnam
longbienvcn@yahoo.com

Abstract

An experiment was conducted to evaluate the effects of including shrimp head meal and cassava leaf meal, and a mixture of the two, in diets for laying hens. A total of 120 hens at 40 weeks of age, and with an initial body weight of 2.52 to 2.55 kg were allocated to 4 treatments and 3 replications. The diets were formulated according to Vietnamese official standards and treatments included a concentrate (CTRL) diet, based on soya-bean cake, fish meal, maize, cassava root meal and rice bran, and 3 experimental diets in which 30% of the protein of soybean meal and fish meal in the CTRL diet was replaced by cassava leaf meal, shrimp head meal, or a mixture of the two, to give diets CLM, SHM and MIX, respectively.

Inclusion of shrimp head meal and cassava leaf meal in the diet had no effect on final body weight, total number of eggs laid, feed conversion, and survival rate and hatchability. Rate of lay was highest for CTRL and MIX, followed by SHM and CLM. There were no effects of treatment on mean egg weight, yolk weight or Haugh Units. Shell thickness was highest for the control treatment, followed by SHM, CLM and MIX, whereas shell weight was highest for MIX and CLM, followed by SHM and CTRL.

Although differences among treatments were not significant, feed costs were reduced by 2, 5 and 9 % units, respectively, compared to the CTRL, for diets SHM, MIX and CLM. Feed cost per 10 eggs was highest for diet SHM, and was lowest for diet CLM, around 5% lower than for CTRL.

Key words: Cassava leaf meal, egg production, egg quality, hatchability, laying hens, shrimp head meal

Introduction

Poultry production in Vietnam is still inefficient with respect to both egg and meat production. Traditional poultry diets, which are mainly based on maize, cassava and rice bran are very low in protein content, and fish meal is very expensive compared to by-products such as shrimp by-product and cassava leaf meal. Cassava is an important crop in the small- farm sector in Vietnam. Many researchers showed that cassava leaf has a high protein content (from 16.7 to 39.9 %), with almost 85% of the crude protein fraction as true protein (Ravindran 1993). It is a readily available product at the time of harvesting the roots.

Shrimp production has increased by around 10% in the period from 1990 to 1998, and is an important export product in Vietnam. The total out put was estimated to be over 80,000 tonnes in 2000 (General Statistical Office 2001). Currently, shrimp by products are sun dried and ground to obtain shrimp meal, which may be effectively used in the feed industry. Shrimp head meal is a by-product from shrimp processing and has a high nutritive value (Ngo Huu Toan and Le Duc Ngoan 2003). A trial in which shrimp head meal was included at 3.2% in a diet for growing chickens from 0-4 weeks of age, and at 1.6% from 5-7 weeks of age, gave good results. In a study on Leghorn laying hens it was concluded that shrimp head meal could be successfully included as a protein source at the level of 37% in the diet, replacing fish meal protein (Nguyen Ngoc Thach et al 1995). In a study using Luong Phuong Hoa laying hens carried out in Central Vietnam it was found that 50% of the concentrate in the diet could be replaced by shrimp by-product meal without reducing laying performance or egg quality, and with substantial savings in feed costs (Ngo Huu Toan and Le Duc Ngoan 2003).

The trial was conducted with the objective of evaluating the effects of including cassava leaf meal and shrimp head meal, and a mixture of the two, in diets for laying hens on egg performance, egg quality and economic benefits.

Materials and methods

Treatments and design

A total of 120 of Luong Phuong Hoa laying hens at 40 weeks of age were allocated to 12 pens (10 birds/pen) following a completely randomised design with 4 treatments and 3 replicates for each treatment. In each pen, there were also 2 cockerels. The experimental design is shown in Table 1 and was based on the design of an earlier study using Luong Phuong Hoa hens (Le Hong Son et al 2003).

Table 1. Experimental design
	CTRL	SHM	CLM	MIX
Number of hens	30	30	30	30
Age at start of experiment (weeks)	40	40	40	40
Duration of experiment (months)	4	4	4	4

The treatments were:

• CTRL: a basal diet formulated to meet the nutrient requirements of Luong Phuong Hoa hens (NIAH 1995);

• SHM: basal diet, but with 30% of the crude protein in soybean meal and fish meal replaced by shrimp head meal;

• CLM: basal diet, but with 30% of the crude protein in soybean meal and fish meal replaced by cassava leaf meal;

• MIX:  basal diet, but with30% of the crude protein in soybean meal and fish meal replaced by a mixture of shrimp head meal and cassava leaf meal.

The experimental diets were offered ad-libitum throughout the 4-month experimental period.

Feeding and management

Shrimp head meal and cassava leaf meal were produced by sun-drying the wet materials and then grinding the product into a meal. There were 10 hens and two cockerels per pen. The birds were fed 3 times per day and a fresh batch of concentrate was made each week. Water was freely available and was changed two times per day. The ingredient and chemical composition of the experimental diets are shown in Table 2.

Table 2. Ingredient and chemical composition of the experimental diets
	CTRL	SHM	CLM	MIX
Ingredient composition, % as fed
Maize meal	37.0	39.9	38.5	42.2
Rice bran	11.0	9.55	9.00	5.75
Cassava root meal	12.3	11.7	6.00	8.80
Soybean meal	22.0	15.4	15.4	15.4
Fish meal	7.5	5.25	5.25	5.25
Di-calcium phosphate	0.5	0.5	0.5	0.5
Ground limestone	4.5	2	3.00	3
Salt	0.2	0.2	0.2	0.2
Shrimp head meal (SHM)	0	10.5		5.3
Cassava leaf meal	0		17.2	8.6
Bone meal	5	5	5	5
Chemical composition, % as fed
Dry matter	85.0	86.9	86.3	86.2
Crude protein	16.2	16.3	16.0	16.1
Calcium	3.1	3.3	3.0	3.2
Crude fibre	1.3	1.4	1.3	1.4
ME, kcal/kg	2750	2789	2704	2760
Phosphorus	0.75	0.78	0.73	0.75
Price, VND/kg*	2734	2646	2441	2544
* Price of the ingredients at the end of 2003

Measurements and statistical analysis

The initial and final weights of the hens were recorded. The number of eggs produced in each pen was recorded daily and 30 eggs in each treatment were taken for determination of yolk weight, shell weight, white weight and internal quality.  Egg yolk colour was measured by the Roche Yolk Colour Fan. Yolk colour values of from 1-6 are classified as light yellow (not satisfactory), from 7-10 as average (satisfactory) and between 11-15 as reddish-yellow (satisfactory). Egg weights were measured to ± 0.1g and thickness of eggshell to ± 0.01mm. Haugh units were measured and the values obtained classified as shown below.

Samples of feeds were taken at intervals for determination of moisture, nitrogen, calcium, phosphorus and energy using standard AOAC methods (AOAC 1990). A total of 300 eggs in each treatment were taken on three occasions to determine hatchability. Data were analysed by ANOVA using the general linear model (GLM) procedure of Minitab version 13.3. Sources of variation were treatments and error. Results are presented as means with their standard error.

Results and discussion

Replacing 30% of the crude protein of soybean meal and fishmeal by shrimp head meal (SHM), cassava leaf meal (CLM) or a mixture of SHM and CLM (MIX) had no effect on final body weight, total number of eggs laid (Table 3), feed conversion, or survival rate and hatchability (Table 4). Rate of lay was highest for CTRL and MIX, followed by SHM and CLM.

Feed costs were reduced by 2, 5 and 9 % units, respectively, compared to the CTRL for diets SHM, MIX and CLM (Table 4). Feed cost per 10 eggs was highest for diet SHM due to the higher consumption of the SHM diet, and was lowest for diet CLM.

There were no effects of treatment on mean egg weight, yolk weight or Haugh Units (Table 5). Shell thickness was highest for the control treatment, followed by SHM, CLM and MIX, whereas shell weight was highest for MIX, followed by CLM, SHM and CTRL. Yolk colour was significantly poorer for the CTRL diet, and best for the diets containing SHM and the mixture of SHM and CLM, as a result of the pigments supplied by these by-products. This is in agreement with a similar study in which the yolk colour of quail eggs was improved by supplementing the diet with cassava leaf meal and field crab roe (Nguyen Thi Tuyet Nhung 2003).

Table 5. Effect of diet on egg weight and quality parameters
	CTRL	SHM	CLM	MIX	P
Egg weight, g	58.9 ± 0.95	57.9 ± 0.97	60.4 ± 1.05	59.2 ± 0.94	0.37
Haugh units	95.3 ± 1.47	93.5 ± 1.29	94.2 ± 1.39	94.2 ± 1.39	0.85
Yolk color	8.83d ± 0.24	10.06a ± 0.24	9.44c ±0.24	9.60b ±0.24	0.01
Weight of egg shell, g	6.47d ± 0.10	6.61c ± 0.16	6.83b ± 0.11	6.90a ± 0.10	0.02
Thickness egg shell, mm	0.39a ± 0.37	0.38b ± 0.37	0.37c ± 0.40	0.37c  ± 0.36	0.01
Yolk weight, g	18.95 ± 0.28	18.93 ± 0.28	19.43 ± 0.31	19.01 ± 0.27	0.62

 

Conclusions and recommendations

• Cassava leaf meal is a potentially valuable protein supplement that can be included in diets for Luong Phuong Hoa laying hens, replacing 30% of the protein supplied by soybean meal cake and fish meal. At this level of inclusion most egg performance parameters were not affected, and egg yolk colour was improved compared to the control diet. Diet cost per 10 eggs produced was about 5% lower compared to the control diet.

• The cost of the shrimp head meal diet per 10 eggs produced was 4% higher than that of the control diet, and although yolk colour was improved it would not be economical to include shrimp head meal at current prices in laying hen diets at the 30% level of replacement.

• Replacing conventional protein concentrates with a mixture of shrimp head meal and cassava leaf meal gave similar performance and economic results as for cassava leaf meal alone.

Acknowledgements

We would like to express our thanks to the SAREC-MEKARN programme for financial support to the senior author for this project.

References

AOAC 1990 Official methods of analysis. 15th Edition. Association of Official Agricultural Chemists, Washington DC.

General Statistical Office 2001  Statistical Yearbook. Statistical Publishing House, Ho Chi Minh City, Vietnam.

Le Hong Son, Tran Quoc Viet and Le Thu Hien 2003  Study on of suitable energy and protein levels in rations for Luong Phuong Hoa laying hens. Agricultural Publishing House, Hanoi.

Ngo Huu Toan and Le Duc Ngoan 2003 Evaluation of Shrimp By-Product for Laying Hens in Smallholder Systems in Thua Thien Hue Province.  In: Proceedings of Final National Seminar-Workshop on Sustainable Livestock Production on Local Feed Resources (Editors: Reg Preston and Brian Ogle). HUAF-SAREC, Hue City, 25 – 28 March, 2003. Retrieved, from http://www.mekarn.org/sarec03/toan.htm

Nguyen Thi Tuyet Nhung 2003 Improving the Yolk Colour of Quail Eggs by Supplementing  the Rations with Cassava Leaf meal and Field Crab Roe;  In: Proceedings of Final National Seminar-Workshop on Sustainable Livestock Production on Local Feed Resources (Editors: Reg Preston and Brian Ogle). HUAF-SAREC, Hue City, 25 – 28 March, 2003. Retrieved, from http://www.mekarn.org/sarec03/nhung.htm

Pham Cong Thieu and Tran Quoc Viet 2003 Study to determine the demand for canxi, total phosphorus and absorb phosphorus of Luong Phuong laying hens Science report 12 - 2003. The National Institute of Animal Husbandry.

Ravindran V 1993  Cassava leaves as animal feed: Potential and limitations. Journal of the Science of Food and Agriculture. 61: 141 - 150.

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