Growth and reproductive indices of snails fed varying proportions of leaves of Moringa oleifera and Pawpaw (Carica papaya)

J O Fayenuwo, Y A Popoola, A J Omole, O A Owosibo, B J Harry and T O Olorungbohunmi

Awolowo University, Institute Of Agricultural Research and Training, Moor Plantation, Ibadan, Nigeria
omoleboye@yahoo.com

Abstract

The study was designed to determine the feed intake, weight gain, feed conversion and reproductive indices of snails fed varying proportion of Moringa oleifera (MG) and pawpaw (PL) leaves. One hundred and fifty snails, mean weight 66.5±2.8g were randomly allotted to five dietary treatments, replicated three times. Each replicate contained ten snails. The snails were fed solely on pawpaw leaf (PL) or moringa leaf (MG) or mixtures of PL and MG. The snails in MGO were fed only pawpaw leaf, MG25 received 75% PL+ 25%MG, MG50 had 50% PL+ 50%MG, MG75 had 25% PL+ 75%MG and MG100 were only MG.

For all growth and reproductive traits there were positive curvilinear trends with optimum values when the snails were fed with75% substitution of Pawpaw leaves by Moringa leaves.

Keywords: feed conversion, growth, reproduction

Introduction

For snail production, there are many feed resources such as pawpaw leaf, peels of mango, pineapple and banana (Akinnusi 2014; Kehinde 2009; Omole et al 2012; Hamzat and Longe 2014). There is a need to identify more feed resources that are readily available. Moringa oleifera has been identified as an exceptionally nutritious tree with a variety of potential uses; it is regarded as the tree of life. The tree varies in height with an average of 5-12 m, with an open, umbrella -shaped crown, and with a straight trunk (10-30 cm thick) with corky, whitish bark. It produces a tuberous tap root which helps to explain its tolerance to drought conditions. Originally considered a tree of the tropics, it easily adapts to hot, humid, wet conditions with annual rainfall in excess of 3000 mm but it yields much less foliage where it is continuously under water stress (Acda et al 2009; Olugbemi et al 2011). Moringa can be grown easily from seeds and cuttings. It needs little care, although pruning is advisable to prevent the tree from becoming lanky; it is easy to harvest. The tree starts flowering and fruiting one year after planting. Moringa compared with other plants is not affected by any serious diseases or insect pests. Moringa oleifera leaf contains crude protein of about 30-34% depending on the variety, stages of development and season. The crude fiber ranges between 12 and 19% depending on the above mentioned factors, while it is rich in minerals such as calcium ad phosphorus (Acda et al 2009; Olugbemi et al 2011).

This study was designed to evaluate the performance and reproductive indices of snails fed solely, or on mixtures of Moringa oleifera and pawpaw leaves.

Materials and methods

The experiment was carried out at the Snail Unit of the Institute of Agricultural Research and Training (I.A.R.& T.), Moor Plantation which is located on Longitude 03°51E, Latitude 07°23N and Altitude 650” in the humid zone of the rainforest belt of Southwestern Nigeria with mean annual rainfall of 1220 mm and mean temperature of 26°C.

One hundred and fifty snails, mean weight 66.5±2.8g were randomly allotted into five dietary treatments, replicated three times. Each replicate contained ten snails. The snails were fed solely on pawpaw leaf (PL) or moringa leaf (MG) or mixtures of PL and MG. The snails in MGO were fed only pawpaw leaf, MG25 received 75% PL+ 25%MG, MG50 had 50% PL+ 50%MG, MG75 had 25% PL+ 75%MG and MG0 had only MG.

The snails were reared in a cage of 12 compartments, each with a dimension of 0.5x 0.5m². Feed intake and weight gain were measured on daily and weekly basis by using a sensitive weighing balance. Feed intake was calculated by subtracting the left-over feed from the feed offered while the weight gain was calculated by deducting the initial weight from the final weight. Shell length and width were measured on weekly basis with a vernier caliper. Micrometer screw gauge was used to measure the shell thickness. Feed conversion ratio was calculated as the ratio of feed intake to weight gain. The reproductive indices such as incubation period, weight, shell length and width of the eggs and that of the hatchlings at day old were counted, measured or calculated. The chemical composition of the experimental diets was carried out according to the method of AOAC (1990). All data were subjected to analysis of variance (SAS 2000) and where differences were observed, means were further separated by Duncan multiple range test.

Results and Discussion

Moringa leaf had high crude protein content similar to pawpaw leaf (Table 1). It has been documented that moringa leaf is rich in minerals and vitamins, and it is used as anti-oxidant in diets of livestock and humans (Acda et al 2009). The crude fiber levels in both leaves were relatively low.

Live weight gain and feed conversion were improved by replacing Pawpaw leaf by Moringa leaf in both cases with curvilinear trends with optimum values at about 75% substitution of Pawpaw leaf by Moringa leaf (Table 2; Figures 1 and 2). Data for shell development showed similar trends.

Figure 1. Weight gain of snails fed increasing proportions of Moringa leaves (MG) replacing Pawpaw leaves

Figure 2. Feed conversion of snails fed increasing proportions of Moringa leaves (MG) replacing Pawpaw leaves

The pattern of reproductive performance was similar to that observed for growth and feed conversion with curvilinear trends showing optimum values at 75% substitution of Pawpaw leaves by Moringa leaves (Table 3; Figure 3).

Figure 3. Egg production of snails fed increasing proportions of Moringa leaves (MG) replacing Pawpaw leaves

The similar responses in number of eggs laid and weight gain to replacing Pawpaw leaves by Moringa leaves is in agreement with the report of Hamzat and Longe (2014) that there is a positive correlation between the size of the eggs and size of snails that laid the eggs. Also, positive relationships exist between the eggs and the size of the newborn (Kehinde 2009).

Conclusions

• For all growth and reproductive traits there were positive curvilinear trends with optimum values when the snails were fed with 75% substitution of Pawpaw leaves by Moringa leaves.

References

Acda P, Masilungan A G D and Moog B A 2009 Partial substitution of commercial swine feeds with (Moringa oleifera Lam) leaf meal under backyard conditions. Proceedings of the PSAS 4thNational and 27thVisayas Chapter Scientific Seminar and Annual Convention,Cebu City. 21-23 October 2009

Akinnusi F A O 2014 Snail Production and Management. Tolukoya Print House, Abeokuta, Ogun State.

AOAC 1990 Association of Official Analytical Chemist. Official Methods of Analysis, 13^th Edition, Washington, DC.

Hamzat R A and Longe O G 2014 Performance characteristics and economics analysis of snailets (Achahatina marginata) fed varying dietary inclusion of Kola Testa. Proceedings of the 3^rd International Conference on Giant African Land Snails held at Federal College of Education Osiele, Abeokuta on 14 June, 2014. Pp.87-90

Kehinde A J 2009 Utilization of cassava peel products in the life cycle feeding of snails (Archachatina marginata).Ph.D Thesis, Department of Animal Science, University of Ibadan.

Olugbemi T S, Mutayoba S K and Lekule F P 2011 Moringa oleifera leaf meal as a Hypocholesterolemic agent in laying hen diets. Livestock Research for Rural Development. Volume 22, Article #84. Retrieved August 18, 2013, from http://www.lrrd.org/lrrd22/4/olug22084.htm

Omole A J, Osunkeye O J, Ojejide J O, Sodamola M O and Poopola Y A 2012 Back To Agric. Series (10). The African Giant Land Snails. Green Choice publications 76p

SAS 2000 SAS. User’s Guide. Statistical Analysis System Institute, Inc.Cary, N.C.

Received 8 November 2018; Accepted 8 February 2019; Published 4 March 2019

Go to top