Effects of the Level and Frequency of Fertilization with hen Droppings on Zooplanktonic Density and Growth Performance of Common Carp Post-Larvae (CyprinusCarpio)

Zooplankton production and growth performance of post-larvae of common carp according to the level and frequency of fertilization with chicken droppings were studied between May and October 2017 at the IRAD pisciculture station in Foumban. To this end, two doses of hen droppings, namely 450 g/m3 (D450) and 600 g/m3 (D600), were each applied at two application frequencies (weekly (F2) and bimonthly (F1)). Thus, 1200 post-carp larvae were distributed in 12 identical concrete tanks (1.2m x 0.75m x 1m) each filled with 400 liters of water. The 2 doses applied at 2 frequencies were applied randomly in the 12 tanks in a complete random device comprising 3 treatments and 2 repetitions. Six days after fertilization, each tank was sown with zooplankton at a density of 7 individuals per liter (ind/l). The loading was carried out 12 days after fertilization at a density of 100 ind/m2. The results show that regardless of the dose and the frequency of droppings applied, the production of zooplankton was optimal 10 to 12 days after fertilization. Considering the growth performance, the tanks receiving the 600 g/m3 dose every 2 weeks presented the highest significant values ​​(p <0.05). On the other hand, the survival rate (36% on average) was not significantly influenced (p˃0.05) by the dose and the frequency of fertilization. The 600 g/m3 dose applied every two weeks can be recommended for the rearing of post-larvae common carp.

Growth Performance of Heteroclarias Juveniles Fed Graded Levels of Autoclaved Castor Seed (Ricinus communis L.) Cake Based Diets

An 84 day feeding trial was conducted on the juveniles (42.51±0.09g) of hybrid catfish, Heteroclarias, in order to evaluate the nutritional potential of 30 minutes autoclaved castor seed cake isonitrogenous (40% crude protein) and isocaloric (3212Kcal/Kg) diets replacing soybean meal at 0, 12.5, 25, 37.5 and 50%, the diets being designated D1, D2, D3, D4 and D5 respectively. Prior to this, the castor seeds (Ricinus communis L.), ZiboCastor No. 3 variety, collected from Ado-Ekiti metropolis, Nigeria were subjected to 0, 20, 30 and 40 minutes autoclaved at 121oC, dehauled, grounded, oil extracted to form cake, then the proximate and antinutrients analysis were carried out. The preliminary tests on the seeds revealed 30 minutes level of autoclaved seeds was the best. The growth performance result showed that there were significant differences (p<0.05) in the mean weight gain (MWG), specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER) and apparent net protein utilization (NPU) among the various diet levels with the progressive decline in the values of each parameter (except FCR that showed progressive increment) along the trend of increment of castor seed cake inclusion (D1, 0%; D2, 12.5%; D3, 25%; D4, 37.5% and D5, 50%). The survival rate followed the same trend of declination with the highest percentage recorded for D1 (93.33±6.67%), followed by D2 (83.33±3.33%), D3 (76.57±3.33%), D4 (66.67±3.33%) and D5 (60.00±5.77%) respectively. Hence the best growth performance and nutrient utilization was shown in D1 (control) followed by D2. It is therefore recommended that autoclaved castor seed cake at 121oC be included at not more than 12.5% inclusion level to reduce cost of feed without necessarily compromising fish growth rate.

Reproductive Parameters of Three Populations of Oreochromis Niloticus (Linnaeus, 1758) in the Sudano-Guinean Altitude Zone of Cameroon

In order to contribute to the improvement of aquaculture production, reproductive parameters of three populations of Oreochromis niloticus of Cameroon were studied between March and May 2019 at the research station of Foumban. At this effect, a total of 81 parents (27 males and 51 females with respective weight 124 ± 6g and 144 ± 5​​g) coming from three hydrogeographicals origins (Niger, Sanaga and IRAD Station) were randomly distributed in triplicate in nine concrete tanks of a m² each with a sex ratio of one male for two females (1♂/2♀). Throughout the test, six females carrying eggs in the oral cavity were collected in each population and 45 days after the start of the trial, all the offspring were collected and the adults sacrificed. At the end of experiment, the IRAD population presented highest significant values (p ≤ 0.05) regardless of the performances considered. The values of the gonado-somatic and the gonado-metric characteristics significantly lower (p ≤ 0.05) were obtained in Niger population (GSR = 0.04 ± 0.02, GSI = 0.05 ± 0.03 and GMR=0.19 ± 0.08;GMI= 0.24±0.07). Considering sex, males presented the lowest significant values (p ≤ 0.05) for all the characteristics studied (GSR = 0.04±0.01, GSI = 0.04±0.01 and GMR= 0.23±0.08;GMI= 0.29±0.09).

Study of Organic Pollutants in the Muscles of fish Collected from El-Mahmodia Stream at El-Beheira Governorate, Egypt

The purpose of this study is to evaluate the impact of organic pollution of EL-Mahmodia canal on the fish (Oreochromis niloticus)muscles tissues collected from two sites at EL-Mahmodia canal in summer and winter 2017. EL-Mahmodia canal is exposed to excessive of effluents which impact fish. The present results showed high concentrations of organic pollutants, particularly in winter. Organic pollutants were analyzed using the gas-chromatography-mass spectrometry (GC-MS). A variety of environmental screening studies concerning varieties of water pollutants in Egypt, the target of the present study was to scan the organic pollutants of El-Mahmodia stream at El-Beheira Governorate, Egypt within the muscles of Tilapia fish. Within the present study, it was found that; the analysis of fish muscles in summer season showed a high level of organic pollutants. The organic pollutants that are reported in the muscle of fish in the polluted site were reported as; Dimethomorph-(E), Hexestrol, Diisobutyl phthalate, Diamyl phthalate, Di-n-propyl phthalate, Chlorpyrifos, Phorate sulfoxide, Exaltolide (15-Pentadecanolide), Chlorfenapyr, Pyridate, Ethofumesate, Bis (2-ethylhexyl)phthalate, Dicyclohexyl phthalate, Di-n-octyl phthalate, Tricresylphosphate, meta-, XMC (3, 4-Dimethylphenyl N-methyl, XMC (3,5-Dimethylphenyl N-methyl, Hexestrol, Thymol, Kinoprene, Diisobutyl phthalate, Diisobutyl phthalate, Di-n-hexyl phthalate, Di-n-hexyl phthalate, Carbofuran-3-keto, Tefluthrin, cis-, Carbofuran-7-phenol, Carbofuran, Dicyclohexyl phthalate, Di-n-propyl phthalate, Di-n-propyl phthalate, Bis(2-ethylhexyl)phthalate, Ethofumesate, Hexestrol, Kinoprene, Di-n-hexyl phthalate, Exaltolide (15-Pentadecanolide), Spiroxamine metabolite (4-tert-b), Chlorfenapyr, Tricresylphosphate, para, Tricresylphosphate, meta-, Tricresylphosphate, ortho-, XMC (3, 5-Dimethylphenyl N-methyl, XMC (3,4-Dimethylphenyl N-methyl, Fluroxypyr-1-methylheptyl ester, Cashmeran, Propargite metabolite (Cyclohexa), and Quinoclamine. The present results showed that Diisobutyl phthalate, Bis(2-ethylhexyl)phthalate, Pyridate and Ethofumesate were detected in winter season in the polluted site, whereas, Bis (2-ethylhexyl) phthalate, and Pyridate were the only organic pollutants that were found in winter in the reference site. The accumulation patterns of organic pollutants percentage in the polluted site in summer in the muscles of O. niloticus were in the following order: Chlorpyrifos> Diamyl phthalate> Diisobutylphthalate> Di-n-butylphthalate> Diamyl phthalate> Bis (2-ethylhexyl) phthalate, whereas, in the reference site in summer, it was Chlorpyrifos> Chlorfenapyr> Di-n-butylphthalate> Diisobutylphthalate> Hexestrol> Di-nhexyl phthalate. The accumulation patterns of organic pollutants in the polluted site in winter in the muscles of O. niloticus, were in the following order: Bis(2-ethylhexyl)phthalate> Pyridate> Ethofumesate, whereas in the reference site it was; Bis (2-ethylhexyl)phthalate> Pyridate.

Prospects of Integrating Caviaculture and Fish Farming in the Western Region of Cameroon

This study was conducted within three months at the University of Dschang Research and Application Farm (5°44’-5°36’ et 5°44’-5°37’ LN ; 10°06’-9°94’ et 10°06’-9°85’ LE). The main objective was to evaluate the integration perspectives of caviaculture and fishery. Specifically, the study was aimed at evaluating the production of guinea pig dungs, its bromatological composition and appreciating the nitrogen/phosphorus ratio in other to determine the adequate quantities of manure for a proper fertilization of fish ponds. Hence, 96 guinea pigs weighing averagely 390 ± 110g each were randomly distributed into two comparable lots (floor covered with litter and floor without litter) and were subjected to 8 feeds (5 grasses and 3 legumes). Each lot had 6 repetitions of 8 individuals. The animals were fed three times daily within 30 days. The dungs of guinea pigs were collected after three days between 6 and 8am during the experimental period. They were then selected and weighed using and electric balance of 0.1g sensitivity. At the end of the study, the following results were obtained: a guinea pig of 390 ± 110 g in confinement produced between 51.7 ± 0.4 to 60.5 ± 0.7g (fresh weight) of dung per day. The bromatological analysis of these dungs showed that they are made of organic material (80.0%), dry matter (94.3%), crude protein (10.7%), ash (19.9%) and nitrogen (22.7%). These results attesting the richness of these dungs helped in estimating the quantities (103.4g to 206.8g) of dung/day/100m2 for the breeding of 2 to 4 guinea pigs per fish pond of 100 m2 for an integrated breeding (guinea pig-fish).

Effect of Replacement of Fishmeal With Lima Bean Meal on the Zootechnical Performances of African Catfish (Clarias Gariepinus) in the Batié Sub-Division, West Region of Cameroun

This study was conducted to evaluate the effect of the substitution of fishmeal by Lima bean flouron the growth performance, survival rate and feed cost of Clariasgariepinusbetween March and May 2018 within the AIO ICG of the Batié District. It also aimed to contribute to the development of alternative sources of animal protein on a global scale. For this purpose, 300 fry of Clariasgariepinuswith an average weight of 3 ± 1.41g were divided into five batches and fed three times a day with rations corresponding to 5% of their ichthyobiomass. The rations R0, R25 R50, R75 and R100 respectively corresponded to the substitution rates of 0, 25, 50, 75 and 100% of fish meal by that of Lima bean. The physic-chemical characteristics of the water (pH, temperature, dissolved oxygen, nitrites and nitrates) were measured daily. The following results were obtained: The highest weight gains were obtained with the rations R25 (20.56 ± 0.40 g), R50 (20.64 ± 0.32 g), R75 (20.98 ± 0.46 g) and the lowest with the rations of R100 (16.21 ± 0.28 g). The highest average daily gain were 0.36 ± 0.02 g; 0.37 ± 0.01 g ; 0.38 ± 0.01 g respectively for the R0, R50 and R75 rations and the lowest with R100 (0.29 ± 0.01 g). The highest value of the specific growth rate (2.47 ± 0.07%) was obtained with the ration R0 and the lowest (1.61%) with the ration R100. The consumption index reached its highest and lowest values with the rations R100 (4.74 ± 0.42) and R50 (3.57 ± 0.43) respectively, compared to the value of the ration R0 (3.31 ± 0.37) for this parameter. Concerning the condition factor K, the highest value was recorded with the R50 diet (1.11 ± 0.49) while the lowest value was obtained with the R75 diet (0.95 ± 0.45). The cost of producing one kilogram of food was higher with the R25 ration (504.59 FCFA) and lower with the R100 ration (443.20 FCFA). Our results revealed that incorporating 75% Lima bean flour into the feed increases the growth performance of Clariasgariepinus fry and reduces the cost of food production.