Effect of supplementation with cassava leaf hay on growth rate of indigenous (Co) goats and  F1 (Bach Thao x Co) crossbred goats kept under a free ranging system 

Nguyen Ba Mui, Dang Thai Hai, Bui Huy Doanh and T R Preston*

Hanoi University of Agriculture, Vietnam
 (nbmui@yahoo.com)
 *UTA - TOSOLY - Finca Ecológica, Morario - Guapota -
AA # 48 Socorro, Santander, Santander del Sur, Colombia

 

Abstract

An experiment was conducted to investigate the effect of supplementation with cassava leaf hay on growth rate of Co goat and  F1 (Bach Thao x Co) in Luc Yen district Yen Bai province. Eight Co goats and eight F1 goats (Bach Thao x Co) of about 5-6 months of age  were randomly allotted to one of two blocks according to weight and sex. The control, goats were grazed during 4 hours per day. The treatments were levels of supplementation dried cassava leaves at 1% live weight per head per day.

Results showed that the HCN content of fresh cassava leaves was higher than the HCN content of cassava leaf hay. The HCN content of fresh cassava leaves was reduced quickly from 2802.67 down 669.27 mg/kg DM after sun-dried for 3-4 days. The 76.13% reduction in the HCN content of the dried cassava leaves compared with the fresh cassava leaves.

After 3 experimental months, DM intake, live weight of the trial goats were higher than the control goats both Co goat and F1 (Bach Thao x Co). The Co goats supplemented cassava leaf hay had daily weight gain higher than from Co goats without supplement cassava leaf hay, but the difference was not significant (P>0.05). Average daily weight of F1 (Bach Thao x Co) supplemented cassava leaf hay were higher than the goats without supplementation (P<0.05).

Key words: Goats, growth, cassava leaf, hay, supplementation,  feed intake, grazing

Introduction

Cassava (Manihot esculenta, Crant) is cultivated in Vietnam in an area exceeding 250,000 ha (Bui van Chinh and Le Viet Ly 2001). Traditionally the crop is grown for the roots, which are used as human and animal food and industrially as a source of starch. In recent years, attention has been focused on the leaves as feed for ruminants (Preston 2001; Wanapat 2001). According to Nguyen Thi Mui (1994), in North Vietnam the leaf biomass available when the root is harvested is about 5 tonnes per ha. The root biomass yield is of the order of 15 tonnes/ha. An important point is that the harvesting time of cassava in North Vietnam coincides with the dry season, when air humidity is very low, convenient for sun-drying of the products. Yen Bai province in Vietnam, cassava is widely grown, roots of cassava can be used as food for people or processing cassava starch, after harvesting a large amount of cassava leaves is put on the hills for drying.

The main limiting factor to the use of cassava leaves as animal feed is the presence of cyanogenic glucosides, which give rise to hydrocyanic acid (HCN) when the plant tissue is broken down by processing or during ingestion by animals. The cyanide levels in leaves are influenced by genetic, physiological, edaphic and climatic differences with the stage of maturity being perhaps the major source of variation (Ravindran 1995).

Yen Bai province is a central region of North mountain in Vietnam, which natural land is 6887.77 km², occupied 2.1% natural area of the whole country. 70% of natural area is forestry land in Yen Bai. The is only 10% of natural area is agricultural land. Total population is 731784 persons including ethnic groups such as Tay, Nung, Giao, H'Mong, Thai, Muong, San Chay, Giay, Kho Mu…

Goat raising of Yen Bai was not interested in the past years, breeding mainly concentrated in the upland districts such as Tram Tau, Mu Cang Chai, Luc Yen, Van Chan.  The household farms are small size, breeding work, care, feed has not been interested, goat raising is mainly extensive farming. Goat breed is main Co goat, which is small body size and slow weight gain. Currently Yen Bai province has 30.000 goats. Goat raising is mainly in rural households. Raising follows method of extensive farming, grazing of 3-4 hours per day, without adding the grain for goats, so weight gain is slow. Body weight of Co goat at 12 months old, male goat was 18-20 kg; female goat weighing was 14-17 kg (Nguyen Dinh Minh, 2002). Effective of goat raising in farm households are low, it don’t promote potential of Yen Bai.

Extensional department of Luc Yen district imported some male goats of Bach Thao to improve the local goats, but people still feed the hybrid goats according to method of extensive farming, grazing only, no supplement grain and rich feed in protein. Nutritional value of plants and grass that goats grazed is not enough to demand for growing goats especially protein. Therefore, growth rate of hybrid goats is low or disease infected. Some households tend to feed back local goat breed.

Objectives

§  The aims of the present research are therefore to improve diets will improve growth performance and meat productivity of goats by keeping under a free ranging system.

§  Cassava leaf hay was supplemented for the goats to help farmers reserving the cassava leaves after harvesting roots.

Material and methods

Effect of type of cassava  leaves on chemical composition

Two varieties of cassava were grown mainly in Yen Bai province. That were red and white cassava. Samples of leaves were taken at the time of six age months after planting from the leaves at the bottom. Determinations were made of dry matter (DM), crude protein, crude fibre, ash and HCN according to AOAC (1990) procedures.

Effect of drying on HCN content

Leaves of red and white cassava from at the bottom were collected at 9.00 am and sun-dried for 3-4 days. Sun-drying consisted of spreading the leaves on the ground and turning them over while exposed to the sun, dried cassava leaves for direct feeding or storage. Samples of cassava leaf hay were taken for determination on dry matter (DM), crude protein, crude fibre and HCN according to AOAC (1990) procedures.

Effect of supplementation with cassava leaf hay on growth rate of Co goat and  F1 (Bach Thao x Co)

The treatments were arranged in completely randomized design for each breed (table 1). The animals were allocated to 4 plots on the basis of sex (8 males and 8 females) and live weight. The animals were numbered. The treatments were level of cassava leaf hay supplementation at 1% live weight per head per day with Co goats and F1 (Bach Thao x Co). The goats were grazed four hours in the afternoon, cassava leaf hay was given in the evening. Water was provided in free.

Measurements

Records were kept daily of amounts of cassava leaf hay offered and refused. Representative samples were taken for analysis of DM, crude protein according to AOAC (1990) procedures. The goats were weighed at the beginning and the end of each experimental month.

 

Statistical analysis

The data was analysed using the SAS.2001. The duncan test for paired comparisons was used to compare means.

Results and discussion

Chemical composition of two cassava varieties

The composition of the leaves of two cassava varieties, taken from the fresh and dry samples of the plant at the six age months, ranged from 16.72 to 21.84 % for crude protein (in DM), 22.54 to 31.30% for crude fibre (in DM) and  7.97 to 12.69% for ash (in DM) (Table 2). The range for crude protein content was less than that reported by Du Thanh Hang and Preston (2005) (23.7 to 29.5% in DM) and by Bui Huy Nhu Phuc et al (2001) for cassava varieties in the South of Vietnam (21 to 34 % in DM). Other researchers have also shown that there is considerable variation in the chemical composition among leaves of different cassava varieties (Ravindran 1990; Eggum 1970).

Crude protein content of white cassava leaves was higher than the red cassava leaves for both fresh and dry samples (19.0 comparison 16.72% in DM in fresh cassava leaves) and (21.84 comparison 19.49 % in DM in cassava leaf hay) (P<0.05). The protein in cassava leaves has an acceptable array of essential amino acids and compares favourably with alfalfa and soybean meal (Phuc and Lindberg 2001).

Effect of drying  on HCN content

The major concern with the use of cassava leaves as animal feed, is the risk of cyanide toxicity. In this study there was a wide variation in HCN content of two cassava leave varieties from 2614.91 to 2990.43 mg/kg DM in fresh cassava leaf (table 3 and Figure 1). HCN content of white cassava leaves was higher than the red cassava leaf hay (2990.43 comparison 2614.91 mg/kg DM).

The wide variation observed in the HCN content of cassava leaves has been attributed to genetic, physiological, edaphic and climatic differences (Gomez and Valdivieso 1985). In this study the environmental conditions (soil and climate) were similar, thus it is probable that the major factor causing variation in HCN content was genetic. Our result on HCN content of fresh cassava leaves were higher than reported by Du Thanh Hang and Preston (2005) (1018 to 1840 mg/kg DM in fresh cassava leaves). Pham Sy Tiep and Nguyen Van Dong (1998) reported that the HCN content of the leaves at the time of root harvest varied according to age and maturity: 442 (mg/kg fresh matter) in the green leaves at the top of the plant, 365 in green leaves below the top, 42.9 in mature leaves and 14.4 in the oldest leaves. In the present study the leaves taken for analysis were six age months at the bottom, still green, and the average HCN level (657 mg/kg fresh matter) was higher than that reported by Pham Sy Tiep and Nguyen Van Dong (1998) and Duong Thanh Liem (1998) (from 305 to 425 mg/kg fresh leaves).

After sun-dried for 3-4 days, the HCN content of fresh cassava leaves was reduced quickly from 2802.67 down 669.27 mg/kg DM. The 76.13% reduction in the HCN content of the dried cassava leaves compared with the fresh cassava leaves (Table 3 and Figure 2) is less than when wilting is under sunlight when up to 90% reduction in HCN has been reported (Gomez and Valdivieso 1985; Ravindran et al 1987). Wanapat et al (1997) recommended the drying of cassava foliage “not only to reduce moisture but also to decrease hydrocyanic acid to a safe level for ruminants”. However, the implication that the has precursors of hydrocyanic acid (HCN) are a constraint to the feeding of cassava foliage to ruminants not been tested in the same experiment.

Figure 1: Variation in HCN in white and red cassava leaves of fresh samples		Figure 2: Variation in HCN in fresh and dried cassava leaves

Effect of supplementation with cassava leaf hay on growth rate of Co goats

No health problems occurred during the experimental period. Table 4 and Figure 3 shows that the animal body weight, daily weight gain and cassava leaf hay intake of the Co goats on the different between control and trial. Body weight of goat of the plots at the end (third month of experiment) were not different (P>0.05). Average daily weight gain of Co goats were 63.89, 78.76 g/day respectively the control and trial plots. Although the local goats supplemented cassava leaf hay had daily weight gain higher than from Co goats without supplement cassava leaf hay, but the difference was not significant (P>0.05).

The low nutritive value of tropical grasses and roughage, and the lack of feed in the dry season are very common features which influence small ruminant production systems in Vietnam, especially in hilly and mountainous areas. Therefore, there is a need to find new feed resources to be used as low-cost supplements to improve animal productivity, especially in the dry season.

Our experiments carried out from June to September 2010, this time the grass and tree leaves were abundant on the hills and forest. Although only 4 hours of grazing, but due to small body size of local goats, the amount of feed intake on pasture were not shortages. So the goats supplemented cassava leaf hay had daily weight gain higher than from Co goats without supplement cassava leaf hay, but the difference was not significant (P>0.05). In winter, when natural feed sources are scarce, the supplement of cassava leaf hay for the local goats would be more efficient.

Effect of supplementation with cassava leaf hay on growth rate of  F1 (Bach Thao x Co)

There were no signs or symptoms of disease or HCN toxicity in the animals during the experiment. Animals were in good healthy and it was observed that the skin became brighter in colour towards the end of the experiment at the trial plot. The changing appearance of the skin observed in this study may have been due to the effect of the protein of cassava leaf hay supplementation.

Table 5 and Figure 4 shows that the goat body weight, daily weight gain and cassava leaf hay intake of the F1 (Bach Thao x Co) on the different between control and trial plots. Body weight of goats supplemented cassava leaf hay at the third month of experiment were higher than the goats of control plot (p<0.05). Average daily weight gain of F1 (Bach Thao x Co) were 67.27, 107.71 g/day respectively the control and trial plots. Average daily weight of F1 (Bach Thao x Co) supplemented cassava leaf hay were higher than the goats without  supplementation (p<0.05). Body weight of goats depends on the inheritance of goat breeds, it also affected by the feeding conditions, different managed care. The goat hybrid of F1 (Bach Thao x Co) have weight gain higher than Co goats (local goat). Therefore with 4 hours of grazing, feed intake of F1 (Bach Thao x Co) were not sufficient for the development needs of the body. So the weight gain of goats of trial plot were higher than the goats of control plot. It may have the effect of the protein and fibre of cassava leaf hay supplementation.

There is a wide range of recent literature showing the beneficial effects of cassava foliage on growth rates and feed conversion of cattle (Ho Thanh Tham et al 2008, Keo Sath et al 2008, Seng Mom et al 2001), goats (Seng Sokerya and Rodriguez 2001, Ho Quang Do et al 2002, Ho Bunyeth and Preston 2004) and on milk yield in dairy cattle (Wanapat 2001). In these different experiments, the cassava foliage was prepared and fed in many different forms: fresh, wilted or ensiled. Bounthavone Kounnavongsa et al (2010) fed fresh and dried cassava foliage for local goats compared with the goats fed sugar cange (Figure 3) and for sugar cas broad dietary e and Gamba grass and reported daily weight gains of 62 g/day in the fresh cassava foliage based diet; 46 g/day in the dried cassava foliage based diet; 55 g/day in the Gamba grass based diet and 52 g/day in the Sugar cane based diet.

Conclusions

• The composition of the leaves of white cassava and red cassava taken from the fresh and dry samples of the plant at the six age months, ranged from 16.72 to 21.84 % for crude protein (in DM), 22.54 to 31.30% for crude fibre (in DM) and  7.97 to 12.69% for ash (in DM).
• The HCN content of fresh cassava leaves was reduced quickly from 2802.67 down 669.27 mg/kg DM after sun-dried for 3-4 days. The 76.13% reduction in the HCN content of the dried cassava leaves compared with the fresh cassava leaves.
• The Co goats supplemented cassava leaf hay had daily weight gain higher than from Co goats without supplement cassava leaf hay, but the difference was not significant (P>0.05).
• Average daily weight of F1 (Bach Thao x Co) supplemented cassava leaf hay were higher than the goats without supplementation (P<0.05).

References

AOAC 1990 Official method of analysis, 13^th edition Association of Official Analytical Chemists, Washington DC.

Bui Huy Nhu Phuc, Ogle B and Lindberg J K 2001 Nutritive value of cassava leaves for monogastric animals; Proceedings of workshop on "Use of cassava as animal feed", Khon Kaen University, Thailand http://www.mekarn.org/procKK/phuc.htm

Bui van Chinh and Le Viet Ly 2001 Study on the processing and use of cassava tops as animal feed. http://www.mekarn.org/prockk/chinh.htm

Bounthavone Kounnavongsa, Vanthong Phengvichith and T R Preston T R 2010 Effects of fresh or sun-dried cassava foliage on growth performance of goats fed basal diets of Gamba grass or sugar cane stalk . Livestock Research for Rural Development. Volume 22, Article #202 . Retrieved , from http://www.lrrd.org/lrrd22/11/boun22202.htm

Ho Quang Do, Vo Van Son, Bui Phan Thu Hang, Vuong Chan Tri and Preston T R 2002 Effect of supplementation of ammoniated rice straw with cassava leaves or grass on intake, digestibility and N retention by goats. . Livestock Research for Rural Development 14 (3) http://www.lrrd.org/lrrd14/3/do143b.htm

Ho Bunyeth and PrestonT R 2004 Preston Growth performance and parasite infestation of goats given cassava leaf silage (or sun-dried cassava leaves) as supplement to grazing in lowland and upland regions of Cambodia http://www.mekarn.org/procsr/buny.pdf

Eggum O L 1970 The protein quality of cassava leaves. British Journal of Nutrition 24:761-769.

Gomez G and Valdivieso M 1985 Cassava foliage: chemical composition, cyanide content and effect of drying on cyanide elimination. Journal of the Science of Food and Agriculture 36: 433-441.

Du Thanh Hang and Preston T R 2005 The effects of simple processing methods of cassava leaves on HCN content and intake by growing pigs.  Livestock Research for Rural Development. Volume 17, Article # 109. Retrieved, from http://www.lrrd.org/lrrd17/09/hang17099.htm

Keo Sath, Borin K and Preston T R 2008 Effect of levels of sun-dried cassava foliage on growth performance of cattle fed rice straw.  Livestock Research for Rural Development. Volume 20, supplement http://www.lrrd.org/lrrd20/supplement/sath2.htm

 

Duong Thanh Liem 1998 Study on the use of different kinds of leaf meal for broiler chickens Agricultural Science and Technology, Hanoi pp: 165-167.

Nguyen Dinh Minh 2002 Research on crossbred between Bach Thao goat with Co goat and  the ability of production of F1 hybrid goat (Bach Thao x Co) in Thai Nguyen province and several surrounding provinces, PhD. thesis, Institute of National Animal Husbandry - Hanoi.

Nguyen Thi Mui 1994  Economic evaluation of growing Elephant grass, Guinea grass, Sugar cane and Cassava as animal feed or as cash crops on Bavi High land. Sustainable Livestock Production on Local Feed Resources. Agricultural Publishing House, Ho Chi Minh city. pp 16-19

Phuc B H N and Lindberg J E 2001 Ileal digestibility of amino acids in growing pigs fed a cassava root meal diet with inclusion of cassava leaves, leucaena leaves and groundnut foliage. Anim. Sci. 72: 511-517.

Preston T R 2001 Potential of cassava in integrated farming systems. Proceedings of workshop on "Use of cassava as animal feed", Khon Kaen University, Thailand http://www.mekarn.org/prockk/pres.htm

Seng Mom, Preston T R, Leng R A and Meulen U ter 2001 Effect of a single drench of cooking oil on the rumen ecosystem and performance of young local "yellow" cattle fed rice straw and cassava foliage  Livestock Research for Rural Development, Volume 13, Number 4, August 2001 http://www.lrrd.org/lrrd13/4/seng134.htm

Seng Sokewrya and Rodriguez Lylian 2001 Foliage from cassava, Flemingia macrophylla and bananas compared with grasses as forage sources for goats: effects on growth rate and intestinal nematodes. Livestock Research for Rural Development, Volume 13, Number 2, April, 2001 http://www.lrrd.org/lrrd13/2/soke132.htm

Ravindran V 1995 Preparation of cassava leaf products and their use as animal feeds. In: Roots, tubers, plantains and bananas in animal feeding, FAO Animal Production and Health Paper, No 95. pp. 11-116.

Ravindran V 1990 Feeding value and digestibility of cassava leaf meal for growing pigs. Proceedings Fifth Australasian Animal Production Congress. Volume 3, Taipei, Taiwan, p.20.

Ravindran V,  Kornegay E T and Rajaguru A S B 1987 Influence of processing methods and storage time on the cyanide potential of cassava leaf meal. Animal Feed Science and Technology 17: 227-234.

Ho Thanh Tham, Man N V and Preston T R 2008 Performance of young cattle fed rice straw sprayed with mixture of urea and molasses supplemented with different levels of cassava leaf meal. Livestock Research for Rural Development. Volume 20, supplement.  http://www.lrrd.org/lrrd20/supplement/tham1.htm

Wanapat M 2001 Role of cassava hay as animal feed in the tropics. Proceedings of workshop on "Use of cassava as animal feed", Khon Kaen University, Thailand http://www.mekarn.org/prockk/wana3.htm

Wanapat M, Pimpa O, Petlum A and Boontao U 1997 Cassava hay: A new strategic feed for ruminants during the dry season, Livestock Research for Rural Development; 1997, Volume 9, Number 2 Metha92.htm