ABSTRACT
This
research aimed to evaluate processed baobab seed meal in the growth of Clarias gariepinus juveniles using fiber
glass tanks stocked with 200 Clarias
gariepinus juveniles per tank. At the end of the experiment, proximate
analysis of the feed used and fish fed on these feeds were carried out. Mucuna had the highest moisture content
of 8.08 + 0.37% as well as the fish fed the Mucuna diet (15.48 + 0.12%). Dry matter was highest in the
commercial feed (94.38 + 0.26%) as well as the fish fed the commercial
diet (89.28 + 0.57%). The highest ash content was observed in baobab
feed (11.58 + 0.45%) although the fish fed Mucuna diet yielded the highest ash content of 13.05 + 0.49%.
Commercial feed obtained the highest ether extract (3.17 + 0.07%) while
the baobab test fish had the highest ether extract (10.32 + 0.86%).
Although baobab seed obtained the highest crude protein level of 54.12 + 9.00%,
the fish fed the commercial diet had the highest crude protein level (63.31 +
1.30%). Carbohydrate level was highest in the commercial feed (33.73 + 1.35%)
while the fish fed the Mucuna diet
obtained the highest carbohydrate level (7.900 + 0.42%). All the test
feed were observed to have compared favorably with the commercial feed and
hence suitable for inclusion at 18% with other feed ingredients as plant
protein sources in the diet of Clarias
garipinus juveniles. All the test fish showed significant difference to
their test feeds (P<0.05). From this research, it is recommended that more
research be carried out on how to effectively utilize all the nutrients found
in plant proteins.
CHAPTER ONE
1.0 INTRODUCTION
1.1 Background to the study
Nigerian
feed resources have been in the decline in the recent years because of the
stagnant or diminishing output of certain crops which demonstrate that the
country increasingly relies on imports to meet the needs of the ever expanding
livestock and aquaculture industries, (FAO, 2008). This has culminated in the
increase in prices of food and feed resources in the country which aggravated
the already precariously high cost of fish feed and has been a major problem to
fish farms in Nigeria. The high cost constitutes 40-60% of the recurrent cost
of most intensive fish farm ventures which negates the economic viability of
the farm when cheaper alternatives are not available, (Madu et al., 2003).
The
African catfish, Clarias gariepinus
is a globally popular aquaculture species largely distributed throughout Africa
and Asia (Hernandez et al., 2004). It is widely culture in fresh water ponds
because of their easiness in reproduction, high growth rate, tolerance to high
densities culture conditions, resistance to disease, excellent flesh quality
and ability to accept a wide variety of feed (Goda et al., 2007). However, its intensive culture is quite limited
because of the high operational cost due to the high protein and commercial
diets which increase their feed comkst (Huttchins-wiese, 2014). The economical
feasible catfish farming can be achieved when it is based on cost efficient
feed compounds of locally available agricultural by-products.
Seed
meals particularly velvet beans (Mucuna
pruriens) is an underutilized legume, able to grow on a low nutrient soil
that may not support other legumes with a crude protein content and amino acid
profile that makes it a potential candidate as a substitute for fishmeal in
fish diets in the tropics. It has a nutritional quality comparable to soybean
and other legumes (Iyayi and Taiwo, 2003), but the seed coat contains high
levels of anti-nutritional factors, the most important being L-dopa, beherenic
acid and lectins (Siddhuraju et al., 1996).
Some processing methods such as boiling, soaking, etc have been reported to
reduce these anti-nutritional factors.
Another
good source of crude protein for fish diet is the Adansonia digitata (Baobab) seed cake. This is also one of the
potential low cost and locally available protein sources in livestock diets for
African aquaculture. The tree produces seed that are not only rich in protein
(20-30% CP) and energy (1898-4465 kcal) but also provides some necessary fiber,
vitamins, minerals and amino acids, particularly lysine and methionine, which
are limited in most cereals but essential for livestock growth and development
(Glew, 1997., Murray et al., 2001). A. digitata seed cake also contains some
anti-nutritional factors such as oxalate, phytate, saponins and tannins but
their levels are generally below the toxic levels for aquaculture (Nkafamiya et al., 2007). The high crude protein
and essential amino acid levels in this seed cake can still be taken as an
advantage at low inclusion level to cut down cost of fish meal in fish diets,
(Mwale et al., 2008).
1.2 Statement of the Problem
Nutrition
is the most important thing to consider in any livestock enterprise. One of the
major problems faced by aquaculture industries today is the high cost of fish
feed and this constitute more of the total cost of production in intensified
culture system, (Ali et al., 2005).
This problem has been attributed to the high cost of fish meal. One approach to
reduce feed cost is by the substitution of fish meal with alternative cheaper
protein sources. Plant protein sources have been widely utilized as partial
replacement of fishmeal (Fagbenro, 1999).
1.3Justification of the Study
As
the need to augment fish production from the wild heightens due to increasingly
demand for fish, there is increased global attention on aquaculture (Owodende et al., 2011). Aquaculture has become
one of the fastest growing food production sectors in which fish meal is a
primary protein source in the fish diets.
Fish
meal is a major and expensive component of fish feed constituting 40-60% of
fish feed production cost (Van weerd., 1995). This could be due to its high
amino acid profile, high digestibility, and feed attractant effect.
Plant
proteins are considered to be the most viable alternative to replace fish meal
in commercial fish feed production. Legumes seed could form a valuable fish
feed component since most of them are rich in protein, mineral, lipid, and carbohydrate,
(Hossain et al., 2001). Also, protein
being a major constituent in fish diets presumes that knowledge of its
requirements for fish species is essential for the formulation of a balanced
diet.
1.4 Objectives of the Study
Ø To
determine the effects of these feeds on the proximate composition of the fish.