CHAPTER ONE
1.0
INTRODUCTION
African
giant land snail belongs to phylum Mollusca, class gastropoda, genius
Archachatina. It is an indigenous African Snail Species and forest dweller in
most forest zones especially West Africa. However it survives and spread easily
in other parts of the world such as Britain and several Islands of Gulf of
Guinea, proving it’s tolerance to temperature and tropical climates (Egonmwan,
1988, Gascogne, 1994). In the last four decades land snails were abundant in
the wild and were easily handpicked.
Nowadays
developments, industrialization, Deforestation, Shortage of food supply in most
of the developing countries are threats to the existence of snail in the wild
and its supply to the market. The insufficiency of animal protein as well as
demand for low or no cholesterol containing meat makes scientists to have
interest in the production of highly nutritive, medicinally important and
efficient by-product utilizer like snail.
Snails
have been well known and highly appreciated by Africans, Nigerians in
particular for the tasty and delicious nature of the meat (Akegbejo and
Akinnusi, 2000) The meatcontain 18-19% crude protein and the high content of
Calcium (Awah, 1992, Britht 1996) plant food materials for snails are seasonal
it is therefore necessary to provide artificial diet that will supply the
nutrients requirement of the animal at all times. This project work was aimed
at determining the effects of moringaoleiferadiets on the growth performance of
young Giant African Land Snails (GALS).
1.1 THE NEED FOR SNAIL REARING/CULTURING
The
advocacy for snail rearing is becoming more popular because of the potential
usefulness of its meat as a good source of protein which is between
15.76-18.26% (Awesu, 1980; Omole et al, 1998). The fat content which ranges
between 0.96-3.0% is low when compared with 9.6,21.4 and 23.0% in chicken, eggs
and mutton respectively (Imevbore and Ademosun 1998). This quality makes snail
meat a choice for hypertensive patients and obsessed (FAO,1986, Odunaiya
1995).Snail meat is also very rich in iron, magnesium, phosphorus, calcium and
nitrogen (Hamzatetal, 2007). The high content of iron in snail meat according
to (Obinnah 1992) makes it useful in correcting the problem in iron deficiency
in man.
However,
as more people become aware of the medical and importance of snail meat, snail
might go into extinction with time (Adeleke ,2002), because the major source
snail supply to most Nigerian consumers is from the wild, which are sold a snails long road sides and local
markets. Hence, efforts are being made to domesticate intensively (Kehindeet al., 2002). It has been reported by
(Amaoet al., 2002) that giant land
snails fed plants food materials supplemented with artificial diet performed
better than their counterparts fed only plants food materials. Feeding cost in
livestock which accounts for over 70% of the total production cost can be
reduced to ensure profitability through the use of forage products. Such forage
products are dried MoringaOleifera seeds, leaf, bark and root which are
obtained from MoringaOleifera plant processing respectively. Their abundance,
cheapness and availability all year round qualify them as good non-conventional
ingredients (Ojebiyiet al., 2010).
MORINGA
OLEIFERA
Moringaolifera,
Lam (M. Olifera) also known as MoringapterygospermaGaertn, is a member of the
Moringaceae family of perennial angiosperm plants, which includes twelve (12)
other species (Olson, 2002) Native of the Sub-Himalayan northern plants of
India, it is cultivated throughout tropical and sub-tropical areas of the
world, where it is known by various vernacular names (Rama Chandra etal, 1980)
with drum stick tree, horse radish tree and malungay being the most commonly
found in the literature. MoringaOleifera is an edible plant. A wide variety of
nutritional and medical virtues have been attributed to its roots, bark,
leaves, flowers, fruits and seeds (Rama Chandra etal 1980, Anwar etal 2007,
Kumar etal 2010) Phyto-chemical analyses have shown that its leaves are
particularly rich in potassium, calcium, phosphorus, iron, vitamins A and D,
essential amino acids, as well as such known antioxidants such as B–carotene, vitamin C and flavonoids
(Bennetttetal 2003, Aslametal 2005, Manguro and Lemmen 2007,Amglo etal 2010,
Gowarishankaretal 2010) the therapeutic use of MoringaOleifera parts in the
Indian sub-continent dates back to Antiquity. In other parts of the world, in
Sub-Saharan Africa in particular, such use appears not have been known by the
wide public, as it is being promoted by diverse organizations as an untapped
opportunity (Thurber and Jahey, 2009, Torimiroetal, 2009).
1.2 BODY WEIGHT IS ONE OF THE GROWTH
PARAMETER
Body
weight is one of the growth parameter used to measure growth rate in animals.
Esmiger and OlentineAkanniet al (2007)
and Akanni(2012) stated that growth in terms of body weight gain is the most
widely used growth index from birth to maturity. Ibon (2009) however reported
that the weight of a Juvenile Snail at hatch is the first indicator of
hatchlings growth rate and is useful as a starting point for measuring
subsequent growth. The author further stated that body parameters (shell
length, shell width and shell thickness) and aperture (shell “mouth’)
parameters indices can be take at hatch and used to measure subsequent snail
growth and growth rate. According to Holness (1991) and Akanni (2012) growth is
measured as an increase in body weight over time and is largely dependent on
the amount of nutrient supply, coupled with the specific tissue. According to
Oguike and Okocha (2007) change in body weight relative to the initial weight
of animal is referred to as growth rate, the author further stated that growth
rate is influenced by such factors as genetics, nutrients, diseases and
hormone. Fiat Zhurgh (1976) sated that body weight has been used by both local
sellers/buyers and researchers as a parameter for selection. Besides Osinowoetal (2007) reported that growth rate in
giant land snails, Archachantinamarginata and Achatinaarchatina has generated
interest among Nigerian researchers as farmers demand recipes for raising
snails to market weight in less time. The junile phase (1-2months) to sexual
maturity (14-26months) is the phase during which every rapid growth takes place
in snails (Cobbinah, 1993). The growth rate of snails varies considerably
between individuals each population group.
In the same vain the author also reported that snails differences in growth rate, weight gain, and
shell growth correlate positively with feed intake in snails. Amisan and
Omidiji(1998) and omole and Kehinde(2005) reported that the body traits of
snails that can be used in the assessment of growth rate are the phenotypic
qualities, especially the shell that is readily seen (Ibom, 2009). This can be
measured in terms of length, width and thickness.Omole and Kehinde (2005),
reported that snails increases as the body size increases and that the shell
makes up 30-40% of the whole body of weight, as et al. Okonetal (2010a)
and Okonetal (2010b) reported highly
significant positive correlations among the morphometric traits of F1
crossed and albino (white skinned) hatchlings (AchachatinaMaginata). A
correlation between body weight and shell measurements can serve as important
factor in marketing, and breeders can use it as guide to improve market value
or quality of breeding stocks.
1.3 JUSTIFICATION OF THE STUDY
This
study becomes apparent and of great significance as it advocates snail rearing
for sustainable economy and improved health status of mankind it also serves as
an eye opener for private individuals, firms, government and agencies to
appreciate the treasure embedded in shell (snails) due to it’s therapeutic
properties which include treatment of whooping cough, hypertension, ulcer and
asthma.
The
study also reveals the nutritional and medical virtues embedded in
moringaoleifera as a wide variety of nutritional importance have been
attributed to its roots, bark, leaves, flowers, fruits and seeds as cited by
Anwar (2007) and Kumar et. al. (2010).
It
further makes comparisons between snailfed with different treatments. So as to
suggest the most appropriate diet for snail rearing both domestic and
commercial purposes.
1.4 OBJECTIVE OF THE STUDY
The general objective of this study
is to evaluate the weigh gain and growth rate of Giant African Land Snails
(GALS) Fed with Moringaoleifera, Millet supplement, fishmeal and dried
water-leaf while the specific objectives are:
·
To prepare four different feed
formulations for the experimental snails.
·
To determine the feed intake and fed
efficiency of the experimental animal (snail)
·
To evaluate the average daily weight
gain to the experimental animals.
·
To determine the genetic parameter
reproductive and growth traits of the experimental animals.
1.5 OPERATIONAL
DEFINATION OF TERMS
SNAILERY: Is a place where edible snails are
bred and fattened for market.
HATCHABILITY: The state of being likely to hatch: a measure
of the ability.
FERTILITY:
Is the state of being fertile: the
fertility of the soil or land.
SPICIE: A group of plant consisting
of similar individuals capable of breeding with each other.
HERMOPHRODITE:Is
an animal that has both male and female sexual organ or characteristics.
SNAILETS: Are the small snails.
SHELL
INDEX: Is the
act of counting and documenting shell.
SHELL
APARATURE: Is the major opening of a shell that the body of the animal may
be retracted
AESTIVATION:
Is the
arrangement of sepals and petals in a flower bud before it opens.
EMBRYONIC
MORTALITY:Is the lost of the conceptus which occure during the
first 42 days of pregnancy, which is the period
from conception to complete differentiation when organ system
develop