Effect of Dietary Garlic Source on Feed Utilization , Growth and Histopathology of the African Catfish ( Clarias gariepinus )

The effects of garlic on the growth, survival and histology of Clarias gariepinus were examined during the period of eight weeks. One hundred and eighty (180) fingerlings with initial mean weight of 3.90 ± 0.02 were stocked at 15 fish per net happa (0.8 cm x 0.6 cm x 0.4 cm) suspended in an earthen pond of (12 m x 12 m x 1.5 m). Triplicate groups of fish with garlic feed inclusion were fed at 3% body weight with four Iso-nitrogenous diet (40% crude protein) in Treatment Diet1 (TD1) (control), Treatment Diet2 (TD2) 10%, Treatment Diet3 (TD3) 20% and Treatment Diet4 (TD4) 30% respectively. At the end of the experiment, mean weight gain (MWG), Feed conversion ratio (FCR), specific growth rate (SGR), protein efficiency ratio (PER) and total protein consumed (TPC) were statistically close among the Treatments. The highest MWG (53.63 ± 0.63) was recorded in fish fed with T4 while the lowest was recorded in fish fed T1 (41.73 ± 0.63). Specific growth ratio (SGR) was high in fish fed T4 (3.04 ± 0.06) and low in T3 (2.32 ± 0.04). The Treatment with the highest Feed conversion ratio (FCR) was T3 (2.57 ± 0.03) and the lowest was in T1 (2.11 ± 0.05). The overall best Treatment was Treatment 4 with 30% inclusion level of garlic source. The histological examinations show no visible lesion in the liver and gut of all the Treatments except Treatment 3 with diffuse vacuolar degeneration of the hepatocytes, the gills in Treatment 4 has the epithelial cells of the secondary lamellae fused and proliferated. Result obtained in this study indicated that 30% garlic inclusion rate in a compounded feed helps in feed utilization and growth Performance with no negative effect to the tissues.


Introduction
The supply of qualitative animal protein in sufficient quantity and at affordable cost has continued to remain a dream yet to be realized.It is a perennial problem and a major challenge to the livestock industry in most developing countries.High costs of feed due to shortage and unavailability of conventional feedstuffs for compounding livestock rations has been the major cause of rising cost of animal products (Sarkiyay, 2010).
Efforts aimed at increasing animal protein supply must necessarily address the competition between man and livestock for feed sources which has often resulted into shortage of such conventional feedstuffs like maize, soya beans and groundnut cake for compounding livestock feeds (Omage et al., 2008).This limitation imposed by scarcity of the conventional feedstuffs has made it necessary to source for alternative and cheaper feed materials to supply nutrients in livestock rations.Such materials would totally or partially substitute the expensive and relatively unavailable conventional feedstuffs and this will directly reduce production cost and improve profitability.It has been studied and reported that in intensive culture of fish breeding in which the fish are fed artificial feeds, the major recurring cost is the cost of feed which is about 60-75% of the operating cost for every cycle.The cost of feeding fish amounts to over two thirds of the operating cost of a fish culture in an intensive system (Eyo, 1990).Garlic is originating in Asia Minor and spontaneously grows in southern Europe, but in cultures, it could be found all over the world.It's a rich source of calcium, phosphorus and vitamin B1; it has a high content of carbohydrates and as a consequence a high nutritive value.Garlic also contains iodine salts which have a positive effect on the circulatory system and rheumatism, silicates which have a positive effect on the skeletal and circulatory system and sulfur salts with positive effects on the skeletal system, cholesterolemia, and liver diseases.Garlic also contains vitamin complex B, vitamins A, C and F (Drăgan, 2008).
Garlic has the following effects: lower the cholesterol and the triglycerides, ameliorates atherosclerosis, has a hypotensive, coronary dilator, antioxidant and anti cancer effect.Garlic contains sulfur containing compounds.Alliin is converted to the anti-microbial active allicin, when the bulb is cut or bruised.Ajoene, which is a secondary degradation product of alliin, is presumably the most active compound responsible for the anti-thrombotic activity of garlic (Wichtl, 2004) the fresh bulb contains alliin, allicin and volatile oils.When the garlic clove is crushed, the odorless compound alliin is converted to allicin, via the enzyme allinase.Allicin gives garlic its characteristic pungent smell (Skidmore-Roth, 2003).Garlic has also been shown to have antioxidant properties, which could have a protective nature against gastrointestinal neoplasias, against blood clots (anti-platelet action) due in part to the compounds alliin and ajoene, which have fibrinolytic activity.Ajoene inhibits thromboxane synthesis through the inhibition of the cyclo-oxygenase and lipoxygenase enzymes (Schulz et al., 2004).
Therefore, this study aims to determine the utilization and additive nature of garlic in the feed with various inclusion levels and to examine the histopathological effect of garlic on the visceral organs of the fish species.

Materials and Methods
One hundred and eighty (Clarias gariepinus) fingerlings with average weight of 3.90 ± 0.02 g were allowed to acclimatize to the environment for one week, and were starved for 24 hrs prior to being placed on experimental system.Ten fingerlings randomly selected samples were sacrificed for carcass analysis before the commencement of the experiment.
The feeding trial was carried out in 12 net happas (0.8 m x 0.4 m x 0.6 m) suspended by bamboo poles with kuralon rope in an earthen pond of size (12 m x 12 m x 1.5 m).Each Treatment was replicated thrice with a control treatment.The swampy nature of the earthen pond had water recharging it from the underground water.
Fifteen (15) fish were selected randomly into each happa and weigh with the use of a sensitive weighing scale (METER TOLEDO FB602) and fed at 5% of their body weight twice daily for a period of 8 weeks between the hours of 07:00-08:00 and 16:00-17:00 GMT.Fish were batch weighed weekly with a sensitive electronic scale and the feeds were adjusted accordingly with their increasing biomass, mortality was monitored daily.Feed conversion ratio, FCR this is obtained by dividing the total weight of the food administered the total increase in weight gained by the fish over a period of time.

Results and Discussion
The initial and final carcass analysis of the fish is represented in Table 3.The moisture content of the fish carcass obtained after the experiment was high in three Treatments compared to the initial value.Treatment 1 was the lowest (71.96%), followed by Treatment 2 (81.41%), and Treatment 4 having the highest moisture content (85.03%).However, Treatment1 recorded the highest crude protein (41.62%) and the lowest was recorded in Treatment 4 (38.03%).Final Carbohydrate of fish carcass ranged between 0.92% in Treatment 1 to 1.12% in Treatment 3. The final dry matters in all the Treatments are lower than the initial values.
Table 5 shows the growth response of fish to different Garlic inclusions in the feed and the mean weekly values of physico-chemical parameters during the experiment are represented in The Mean weekly values of physico-chemical parameters during the experimental periods were within the acceptable range of rearing Clarias gariepinus.This conforms to the result of Adekoya et al. 2004 andFAO, 1992 recommended values for a successful catfish production system.

Statistical Analysis
All data obtained were subjected to one-way ANOVA test Where ANOVA revealed significant differences (P < 0.05), Duncan's multiple-range test (Zar, 1996) was applied to characterize and quantify the differences between treatments using SAS software for windows (SAS, 2009).) and with This is in agreement with the findings of (Fatma, 2009) in the work histopathogical studies on Tilapia zillii and Solea vulgaris from Lake Quarum.Ayotunde et al. (2011), observed no visible lesion on control fish in the work histological changes in O.niloticus exposed to Aqueous extract of Moringa oleifera seeds powder.

Conclusion
Results show that garlic can be conveniently used as a complete phyto-additives in fish diet of African catfish (Clarias gariepinus).In general, the results obtained showed no negative effect on the growth of African catfish and histology of the viscera organs suggesting that it is essentially good for growth and utilization.
From the results, it is clear that there was no negative impact on the survival rate in the use of garlic and there was efficient utilization of feed on weight gain, total protein consumed, feed conversion ratio and moderate feed intake.The significant of the research to fish farmers is that natural growth promoters have fewer disadvantages compared to artificial growth promoters for artificial growth promoters could be bio-accumulated to the final consumers.

Recommendation
For suitable aquaculture practices, majorly in developing countries where the level of awareness on fish drug is low, the use of garlic at higher level is recommended, for the highest inclusion gave the best result.
Further study should be carried out on the most suitable phyto-additives for efficient utilization and immune activity with corresponding analysis on their tissue and blood compositions.
There could be trial on higher inclusion level from 40% upward to further ascertain the maximum possible derivable garlic additive limit in fish compounded feeds.
Initial weight gain; W 2 =Final weight gain; L n = Natural logarithm; Time = Number of days of experiment PER Fish weight gain Protein gain Figure 2. Mean survival rate of different treatments

Table 1
Means along the same row with different superscripts are significantly different (p<0.05).

Table 4
cMeans along the same row with different superscripts are significantly different (p < 0.05).

Table 6 Table 5 .
Ashraf (2008)se of fish to different Garlic inclusion in the feed Clarias gariepinus fingerlings fed varying inclusion levels of garlic for the 8 weeks.The highest survival was obtain in Treatment 4 (72.71 ± 0.61), followed by Treatment 3 (70.40±0.35),Treatment 2 (65.94 ± 0.44) and the least in Treatment 1 (50.77±0.33).This was in support byAshraf (2008)finding on survival of Clarias gariepinus in a net happa suspended in an earthen pond with varying stocking density.Increase in garlic inclusion of feed resulted in higher fish survival.This is similar to the findings ofAyotunde et al. (2005)in the work on toxicity of aqueous extract of drumstic, Moringa oleifera, to fingerling and adult catfish Clarias gariepinus.The mean survival rate of Treatments at the end of the experiment was highest in Treatment 4 (73%) while the lowest was recorded in Treatment 1 (51%).
dMeans along the same row with different superscripts are significantly different (p<0.05)；AFC:AverageFeedConsumed, FCR: Feed Conversion Ratio, SGR: Specific Growth Rate, TPC: Total Protein Consumed, PER: Protein Efficiency Ratio.In Table5, Treatment 4 with 30% garlic inclusion level had the highest final weight per fish (86.10 ± 0.Figure 1.Growth response of C.gariepinus fingerlings fed with garlic base diets for eight weeks There was significant difference (p < 0.05) in the survival rate of