Effects of supplementation of cassava hay as a high protein feed source to the rice straw ration and Vong nem (Erythrina senegalensis), leaves as herbal medicine against helminths, on growth rate and feed utilization efficiency of local beef cattle under household conditions

Tran Quoc Viet and Dao Duc Kien

NIAH, Hanoi, Vietnam
tranquocviet1@hn.vnn.vn

Abstract

Twenty four young beef cattle with initial live weight from 110 to 125 kg were used to investigate effects of supplementation with cassava hay and Vong nem (Erythrina senegalensis) leaves on growth rate and feed utilization efficiency of local beef cattle. Animals were fed a basal diet (rice straw ad libitum, 300 g cassava chips and 500 g fresh cassava residue per head per day) and allotted to 4 treatments: Control: basal diet without Vong nem leaves and cassava hay; VN: Basal diet with 500 g Vong nem leaves per head per day for 3 days per week; CH: basal diet supplemented with cassava hay (500 g per head per day); VN-CH: basal diet supplemented with both Vong nem leaves and cassava hay.

Supplementation of Vong nem leaves to the basal diet did not increased rice straw intake of cattle, but supplementing with cassava hay and or cassava hay with Vong nem leaves increased rice straw intake by 9.5 and 10.4%, respectively. Weight gains of animals given basal diets with cassava hay and or cassava hay and Vong nem leaves were higher than on the control diet . Supplementation with cassava hay and Vong nem leaves decreased number of worm eggs in feces.

It can be concluded that in farmer conditions the supplementation with cassava hay (500 g/head/day) together with fresh Vong nem (Erythrina senegalensis) leaves (500 g/head/day for three days per week) decreased parasitic infection and improved growth performance and feed efficiency in local beef cattle in the winter season.

Key words: Beef cattle, cassava hay, Vong nem (Erythrina senegalensis) leaves, helminths.

Introduction

The cattle population in Vietnam is around 4 million (Statistical yearbook, 2002) and over 80% of these are indigenous breeds (Yellow cattle) characterized by very small size (180-200 kg of body weight at maturity in female and 230-250 kg in male, respectively), low growth rate and meat production. Beef cattle in Vietnam are mainly raised by farmers in mixed farming systems based on utilization of crop residues as main feed ingredients in traditional diets. Scarcity and fluctuation of the quality and quantity of the year-around feed supply have been being big problems for beef cattle production in Vietnam.

Another main constraint to the cattle production in Vietnam is the helminthiasis. According to a report on investigation of parasite infection in ruminants in the small holders' conditions in north Vietnam (Phan Dich Lan 1999), the proportion of infected animals (mainly with Nematodes, Liver fluke and Tripanosoma Evanci) is over 70% under household conditions. This is one of the factors resulting in poor body condition and high mortality in cattle and buffaloes in dry and cold season in north Vietnam.

Cassava leaf, as a crop-residue from cassava production, contains high level of protein as reported by Wanapat et al (1992). Dried cassava leaf has successfully been used as supplement for ruminants fed straw based diets (Bexkorowajnyi et al 1986; Wanapat et al 1993), but in Vietnam utilisation of cassava leaves as protein feed for ruminant is very limited. In some highland areas in the north Vietnam, farmers used to use the leaves or bark of the Vong nem tree (Erythrina senegalensis) as herbal medicine against helminths in cattle and buffaloes.

The objective of this study was to investigate effects of supplementation of dried cassava leaves and Vong nem leaves to traditional rice straw diets on growth performance of local beef cattle under village conditions.

Materials and methods

Location

The study was conducted at Cong hoa village located in a highland area of Hatay province, 35 km north-west of Hanoi. The Cong hoa village is located in the buffer zone between the mountainous area and the Red river delta. The study was carried out in the winter-spring period of 2002-2003.

Cassava hay preparation under household conditions

Twelve households who had been raising beef cattle and planting cassava were selected. Cassava leaves with stem were collected soon after 6 months of planting and dried under sunlight for 24 to 48 hours. After drying, the cassava hays were chopped and stored in sacks for feeding.

Vong nem leaves preparation as a herbal medicine against helminths

Vong nem (Erythrina senegalensis) trees are widely available in the rural areas, especially in the high land and mountainous areas. This tree is grown along the fences of the households. Vong nem leaves were collected every three days in the fresh form as herbal medicine to feed cattle together with other feeds in the evening (according to traditional experiences).

Experimental design

Twenty four young beef cattle with initial live weight from 110 to 125 kg in 12 households were allotted to 4 treatments (Table 1).

Table 1: Experimental design
	Control	VN	CH	VN-CH
House holds	3	3	3	3
Animals per house hold	2	2	2	2
Animals per treatment	6	6	6	6
Adaptation (days)	15	15	15	15
Experimental duration (days)	120	120	120	120
Roughage
Rice straw	Yes	Yes	Yes	Yes
Feeding regime	ad lib	ad lib	ad lib	ad lib
Supplement (g/head/day)
- Cassava chips + FCR¹	300 + 500	300 + 500	300 + 500	300 + 500
- Cassava hay	No	No	500	500
- Fresh Vong nem leaves²	No	500	No	500
¹FCR = Fresh cassava residue; ²Fresh Vong nem leaves supplemented for three days every week given with other feeds in the evening.

Measurements.

Feeds offered and refused were recorded daily to calculate feed intake and feed conversion ratio. Body weights were recorded every two weeks and linear regression analysis used to estimate rate of live weight gain. Faeces samples were collected at :the beginning and 10 and 30 days later for counting nematodes eggs. Faeces sample preparation and counting were carried out in Department of Animal Parasitology of the National Veterinary Institute.

Results and discussion

Effects of supplementation of cassava hay to rice straw diets on feed intake and growth rate of local cattle.

Quantity and quality of feed resources in Vietnam have been limited by seasonality and their nutritive values. In the rural areas such as Cong hoa village, the main feed resources for ruminants in the dry season are rice straw and cassava residues (by-products of cassava starch processing). Some households in the winter season also use cassava chips to feed cattle. Apart from these there were no protein feed resources to be used for ruminants. Table 2 shows the chemical composition of the feeds utilized in this study.

Table 2. Chemical composition of the main feed ingredients for animals in the experiments (% in DM)
	Moisture	CP	EE	CF	Ash	NDF	ADF
	%	As % of DM
Rice straw	8.3	3.8	2.1	32.5	15.9	71.2	50.6
Cassava hay	12.6	24.2	9.4	15.6	6.5	35.3	27.4
Cassava chips	12.8	3.3	2.9	4.9	2.6	9.7	6.8
Cassava residue	75.7	1.9	2.4	8.7	2.3	14.6	9.7
Vong nem leaf	75.2	11.3	2.7	14.4	4.3	32.1	22.5

The Vong nem (Erythrina senegalensis) tree is widely grown along the fences of the households. Vong nem leaves are not used as a main feed source for ruminants but as a herbal medicine against helminths. In the fresh form, dry matter content of Vong nen leaf is around 25%. Crude protein level in the leaf is not high (11.3% in DM). In this trial, Vong nem leaf was not considered as a feed source and it was utilized only as herbal medicine.

Table 3 : Dry matter intake, feed conversion and growth rate of native cattle fed rice straw supplemented with cassava hay and Vong nem leaves
	Control	VN	CH	VN-CH
Initial weight, kg	112 ± 3.6	123 ± 4.5	118 ± 5.7	127 ± 6.4
Final weight, kg	137 ± 4.7	149 ±7.2	1523 ± 6.3	164 ± 7.2
Average daily gain, gr	206^a	219^a	287^b	309^b
Dry matter intake, kg/day
Rice straw	2.31^a	2.35^a	2.55^b	2.53^b
Cassava chip	0.26	0.26	0.26	0.26
Cassava residue	0.12	0.12	0.12	0.12
Cassava hay	0	0	0.44	0.44
Vong nem leaves	0	0.053	0	0.053
Total DM intake	2.69	2.78	3.37	3.40
Total DM intake as % BW	2.40^a	2.30^a	2.85^b	2.70^b
FCR (kg DM/ kg WG)	13.0	12.7	11.7	10.9
Cost : Benefit ratio	1 : 1.1	1 : 1.15	1 : 1.4	1 : 1.7
ab Means in the same row without common letter are different at P<0.05

Supplementation of the rice straw diets with cassava hay increased rice straw intake and growth rate, but these parameters were not affected by the feeding of Vong Nem leaves (Table 3). This result is in agreement with the findings of Wanapat et al (1989), where cassava hay and cowpea vines as supplements to rice straw diets increased rice straw intake, growth rate and digestibility of cattle and buffaloes. Due to improvement in feed intake and growth performance, supplementation with cassava hay as high protein feed source improved feed utilization efficiency in the local beef cattle in small household conditions. In the winter season, if local beef cattle were fed untreated rice straw diets with very little cassava chips and cassava residues, farmers could not get any benefit from cattle raising (Control diet). Supplementation of cassava hay to basal diets with untreated rice straw, cassava chips and cassava residues increased benefit for farmers (treatments, CH and VN-CH).

Vong nem (Erythrina senegalensis) leaves as herbal medicine

In many rural areas in Vietnam, helminths are recognized as a major constraint to livestock production. Manufactured anthelmintics have long been considered the only effective way for controlling parasitic infection. However, as these are very expensive and often unavailable to the farmers, livestock producers have continued to use indigenous plants as dewormers. In north Vietnam some kinds of plants have been traditionally used such as Vong nem (bark and leaf), pineapple (leaf) and leucaena (seed). Among these, Vong nem is more commonly used. According to DanØet al (1999) the bark of Erythrina senegalensis also has been used as a dewormer in ruminants in some tropical countries. In Vietnam, farmers have used not only bark, but also the fresh leaves. Results of utilization of fresh Vong nem leaves as a dewomer in cattle are shown in Tables 4 and 5.

Table 4: Effects of using Vong nem leaves as herbal medicine on parasite infection in cattle under village conditions.
	Control	VN	CH	VN-CH
Proportion infected by parasites (%)
Beginning of study	100	100	100	100
End of study	100	50	67	33

Utilization of Vong nem leaves and cassava hay, separately or together (Tables 4 and 5), reduced the proportion of cattle infested with parasites and also the faecal egg count.

Table 5: Effects of using Vong nem leaves as herbal medicine on worm eggs in the faeces of cattle in the village conditions (eggs/g of faeces)
Days	Control	VN	CH	VN-CH
0	382 ± 33.7^a	376 ± 26.5^a	397 ± 28.9^a	380 ± 33.7^a
15	379 ± 35.2^a	215 ± 20.3^b	246 ± 19.1^b	205 ± 20.7^b
30	357 ± 29.8^a	150 ± 14.7^c	169 ± 11.5^c	126 ± 4.8^c
60	294 ± 36.4^b	66 ± 10.2^d	73 ± 6.4^d	41 ± 3.4^d
ab Means in the same row without common letter are different at P<0.05

Conclusions

In farmer conditions, cassava hay increased growth rate by 50% and improved the feed conversion by 16% in local beef cattle fed rice straw diets in the winter season in North Vietnam.
Both cassava hay (500 g/head/day) and fresh Vong nem (Erythrina senegalensis) leaves (500 g/head/day for three days per week), separately or together, decreased the level of parasitic infection.

References

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