Nutritional potential of Blighia sapida K Konig (Ackee ackee) leaves as a dry season feed resource for West African dwarf goats in the derived savanna zone of Nigeria

O A Aderinola, G O Farinu, J A Akinlade, T B Olayeni, O O Ojebiyi and P O Ogunniyi

Department of Animal Production and Health, Ladoke Akintola University of Technology, P.M.B. 4000, Ogbomoso, Nigeria
ade4aderinola@yahoo.com
 

Abstract

A feeding trial to evaluate the potential of Blighia sapida K Konig leaves as a dry season feed resource for West African Dwarf goat in the derived savanna zone of Nigeria was carried out. Twenty WAD bucks of comparable age and weight were randomly assigned to five treatment groups of Blighia sapida K Konig: Cynodon dactylon diet in ratio 100:0; 75: 25; 50:50; 25: 75 and 0:100 respectively and each treatment was replicated four times. Data were collected on feed intake and nutrient digestibility and analyzed in a completely randomized design.

Feed intake and nutrient digestibility differed significantly (P<0.05) among treatments. In the parameters measured. 100:0 Bligha sapida: Cynodon dactylon had the highest value followed by Bs. 75:Cd25.

It was concluded based on feed intake and digestibility data that Bligha sapida K Konig leaves could be a very good feed resource for West African Dwarf goats especially in the dry season.

Key words: Bligha sapida  leaves, Cynodon dactylon, feed intake, nutrient digestibility, WAD goat

Introduction

Dry season remains a critical period for successful keeping of small ruminants in the derived savannah zone of Nigeria, hence the use of multipurpose trees (MPTs) and legumes as reliable sources of dry season feeds (Kang'ara et al 1998). A lot of indigenous MPT  exist in the humid zone and some of them are currently being used by smallholder sheep and goat farmers in a cut and carry system of husbandry to sustain their animals especially during the dry season (Oji and Ndiomu 2002).

Efforts have been made in evaluating their suitability as animal feeds (Mohammed and Abdullahi 2001, Oji and Ndiomu 2002). The ability of browse trees to conserve nutrients for a longer time particularly in the dry season is well known. Browse plants contain higher levels of protein, vitamins, and minerals than grasses and crop residues (Bonsi et al 1994). Some of the well known existing browse plants are Leucaena leucocephala and Gliricidia sepium.

The potential of Blighiasapida K Konig leaves for livestock production is yet to be exploited in Nigeria. There is paucity of information especially on its nutritional composition as a forage crop for ruminant animals in the derived savannah zone of Nigeria. Blighia sapida, commonly referred to as Ackee ackee or vegetable brain and locally as "Isin", is an evergreen tree more widely known for the edible part of its fruit. It belongs to the family Sapindaceae and grows to a height of 10 to12m at maturity. It has a trunk of up to 1.8m in circumference and a dense crown of spreading branches. The leaves (Photo 1) are compound with 3-5 pairs of oblong, obovate-oblong or elliptic leaflets of 1.5-3.0cm long and round at the base. It is usually planted as a shade tree. Its fruit is relished by humans and the leaves are eaten by ruminants. Ackee ackee is well known for their poisonous unripe aril that contains hypoglycin A, a water-soluble liver toxin that inhibits gluconeogenesis thus leading to hypoglycemia. However, on exposure to sun as the fruit ripens and splits, the concentration of the toxin falls rapidly to a tolerable level for humans, and the fruit is then boiled or consumed fresh. It is very likely that the leaves contain little or none of this toxic substance since they are always exposed to light and animals are usually seen picking or browsing on the plant. There is however paucity of information on the utilization of Blighia sapida leaves by animals.

Photo 1: Foliage and fruits of Blighia sapida

The objectives of this study were to determine the proximate composition of Ackee (Blighia sapida) leaves and to determine their digestibility in West African Dwarf goats when fed with different proportions of Cynodon dactylon grass.
 

Materials and methods

The trial was carried out in the dry season at the sheep and goat unit of the Teaching and Research farm of Ladoke Akintola University of Technology, Ogbomoso located in the derived savannah zone of Nigeria.

Animals and their management

Twenty male yearling West African dwarf goats with an initial mean weight of 12±1.2kg were used. They were sourced from local markets. A few days prior to the arrival of the animal, the pens and surroundings were cleaned, washed and disinfected with "Iodophor" solution. The floor was covered with bedding. On arrival, animals were treated against internal and external parasites using "Ivomectin" and were later injected with broad-spectrum antibiotics on the 1^st and 3^rd weeks of quarantine. Fresh water was provided ad-libitum. The goats were later housed in metabolism cages for collection of  faecal samples. The treatments are indicated in Table 1.

Blighia sapida branches were harvested from trees located within the teaching and research farm while Cynodon dactylon was harvested from the established pasture plots every morning. B. sapida branches were cut and spread on a concrete floor under the shade and left over-night for about 24h to wilt. Leaves were then stripped from the branches, leaving the stalk on the stem.   Fresh Cynodom dactylon   was manually harvested daily, chopped by hand into 3-5cm lengths and thoroughly mixed with wilted leaves of B. sapida in varying proportions before feeding.

The feeding level was set at 3% of body weight (DM basis); the calculated proportions of the forages were chopped and mixed together before being offered in a trough. Feed offered and refusals were weighed daily The experiment involved an initial period of 14 days to allow the animals to adjust to confinement and the diet, followed by a collection period of 7 days. Total daily faecal output was  measured for each animal and a 10% sample taken and dried to a constant weight in an oven at 105 ⁰C to determine dry matter content.

Chemical analysis

The dried samples were milled and sieved through a 1.0 mm sieve for determination of nitrogen, crude fibre, ether extract and ash. The nitrogen content was determined using Khjeldal apparatus and the CF, EE and Ash by AOAC methods (AOAC 1990).

Statistical analysis

The data were subjected to analysis of variance (SAS 1999) using a completely randomized design (CRD). Means for significant effects were separated using the Duncan (1955) multiple range test.
 

Results and discussion

The crude protein content of Blighia sapida leaves was similar to the crude protein in leaves of Gliricidia sepium (Abdulrazak et al 1997) and Leucaena leucocephala (Vierre and Van 1982) (Table 2). The crude fibre content was low and only half of that in the grass. 

Intakes of DM and crude protein decreased as the Blighia sapida leaves were replaced by the grass (Table 3). Apparent digestibility coefficients showed a similar trend apart from crude fibre which increased with increasing level of the grass. 

The results of this study indicate that the leaves of Blighia sapida are readily consumed by goats and that the DM and crude protein are highly digestible. There were no advantages in introducing  Cynodon dactylon grass as partial or complete replacement of the leaves since this decreased the intake of crude protein and of DM. It is well known that crude protein intake and DM intake and digestibility are positively related (Smith and Van Houtert 1987).

The low nutrient intake recorded for B25C75 diet might be due to the higher percentage of Cynodondactylon in the diet. The high CF content of Cynodon dactylon could be attributed to cell wall lignification, which increases as plant matures, or water stress factor, which was applicable to Cynodon dactylon during the experimental period.

This led to the low digestibility value recorded for the experimental diet with decrease in proportion of Blighia sapida k konig leaves and increasing proportion of Cynodon dactylon. Cynodon dactylon was observed to contain higher CF than Blighiasapida k konig and low CP than Blighia sapida.

The high nutrient digestibility coefficient values recorded for diets containing BS was consistent with the observation of Aye (2002) that fodder trees degrade fairly well rapidly in the rumen and are well digested post ruminal, often at a higher level than tropical grasses.
 

Conclusion

• The animals did not show any negative reaction to the experimental diets.

• The study therefore showed that Blighiasapida leavescould be used as a major feed resource for WAD goats during the dry season in the derived savannah zone to reduce the effect of feed shortage and enhance the poor quality of available grasses and crop residues.
   

References

Abdulrazak S A, Muinga R W, Thorpe W and Orskov E R 1997 Supplementation with Gliricidia sepium and Leuceana leucocephala on voluntary food intake, digestibility, rumen fermentation and live weight of crossbred steers offered Zea mays stover. Livestock Production Science 49, 53-62.

AOAC 1990 Association of Official Analytical Chemist. Official method of analysis.15^th Edition Washington D.C. 69-88.

Aye P A 2002 Effect of Gliricidiasepium leaves on intake and digestibility in West African Dwarf goat fed dried elephant grass. Proceedings of the 27^th Annual Conference of the Nigeria Society for Animal Production. 17^th -21^st March 2002.Federal University of Technology Akure Nigeria.

Bawala T O and Akinsoyinu A O 2002 Nutritional evaluation of browse:Gliricidia sepium and Ficus thoningii foliage in goats diet: 2. Energy utilization and requirement. Proceedings of the 7^th Annual conference of Animal Science Association of Nigeria. September 16-19,2002.University of Agriculture. Abeokuta Nigeria

Bonsi M L K, Osuji P O, Nsahlai I V and Tuah A K 1994 Graded levels of Sesbaniasesban or Leucaena leucocephala as supplements to teff straw given to Ethopian Menz Sheep. Animal Production 59, 235-240

Duncan D B 1995 Multiple range and multiple F-.test Biometrics 11:1-42.

Kang'ara J N N, Shelfford J A, Fisher J L and Tait K R M 1998 The effect of leuceana, callinadra and Gliricidiatannins on dry matter and protein digestibility in ruminants. In. Shelton H M, Gutteridge RM, Mullen B R and Bray R A (editors) Leuceana-Adaptation, quality and farming systems. ACIAR proceeding No 86:268-271.

Mohammed I D and Abdullahi B A 2001 Species abundance and nutritional composition of Browse tree and shrubs in sheep and goats diets in semi arid and part of Yobe State, Nigeria. Proceedings of the 6^th Annual Conference of Animal Science. Association of Nigeria September. 17^th -19^th 2001. University of Maiduguri Nigeria.

Oji U I and Ndiomu F O 2002 Chemical composition of edible portion of selected browse species of the humid forest zone. Proceedings of the 7^th Annual Conference of Animal Science Association of Nigeria September. 16-19 2002. University of Agriculture Abeokuta, Nigeria.

SAS 1995 User's Guide. Statistical Analysis System Institute, Inc. Cary, N.C

Smith O B and Van Houtert M F T 1987 The feeding value of Gliricidiasepium. A review. World Animal Review 62, 57-68.

Vierre O M and Van I M 1982 Effect of dietary protein in gastrointestinal tract of sheep. Nutrition Abstracts Review 53 (18): 52.

Received 22 July 2006; Accepted 21 December 2006; Published 4 June 2007

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