Population dynamics of Chrysichthys nigrodigitatus (Lacépède, 1803) in Ikere-gorge, Oyo State, Nigeria

The growth and mortality parameters of Chrysichthys nigrodigitatus were estimated to assess the sustainability of its exploitation in Ikere-gorge, Oyo State, Nigeria. A total of 1210 of Chrys­ichthys nigrodigitatus were sampled from fishermen catches between January, 2017 and Decem­ber, 2018. C. nigrodigitatus were exploited with gillnet, cast net and traps (Malian trap net and bamboo). Total lengths were measured with fish measuring board. The FAO-ICLARM Stock Assessment Tool (FiSAT II) software was used to analyze length-frequency data of the fish. The estimated growth parameters are: asymptotic length is 60.9 cm, growth coefficient is 0.96, optimum length is 38.51 cm; length at maturity is 33.44 cm while length-at-first-capture is 12.62 cm. The estimated mortality parameters are: total mortality is 3.29 per year, natural mortality is 1.43 per year and fishing mortality is 1.86. It was observed that C. nigrodigitatus of Ikere-gorge were more vulnerable to exploitation at sizes less than their length at maturity. Likewise, the ex­ploitation rate (E = 0.57 yr-1) is greater than sustainable exploitation rate (Emax = 0.46 yr-1). This shows that exploitation of C. nigrodigitatus in Ikere-gorge is not sustainable. Therefore, there is need to reduce fishing pressure on C. nigrodigitatus to ensure its sustainability in Ikere-gorge

Corchorus olitorius stem as corrosion inhibitor on mild steel in sulphuric acid

The corrosion inhibition of mild steel in 0.5M H2SO4 solution was studied in the presence of Corchorus olitorius stem extract as inhibitor. Phytochemical analysis results confirmed the presence of organic constituents such as Alkaloids, Tannins, Glycosides, Saponins and Flavonoids which made the Corchorus olitorius stem extract act as a good inhibitor. The highest inhibition efficiency as observed from the experimental design was 93.29%, with process levels of 4 days, temperature: 60 �C and inhibitor concentration: 1.0 g/L respectively. The optimal process levels were: 4.11 days, temperature: 48.92 �C and inhibitor concentration: 1.16 g/L respectively, which gave an inhibition efficiency of 94.34%. The result from the Scanning Electron Micrographs showed that via the validated experiment, a more passive layer of film was formed on the surface of the coupon, confirming the high efficiency of the Corchorus olitorius extract's inhibiting role in corrosion prevention

Influence of Arbuscular mycorrhiza fungi (AMF) on drought tolerance and charcoal rot disease of cowpea

The influence of Arbuscular mycorrhiza fungi (AMF) (Glomus deserticola and Gigaspora gigantea) were evaluated on drought tolerance and charcoal rot disease of cowpea genotypes: IT90K-277-2, IT84S-2246-4 and IT06K123-1. IT90K-277-2 and IT84S-2246-4 were sown in 3 kg of sterilized soil for drought experiment with five treatments. Treatment was established thirty days after germination with inoculation of G. deserticola, the mycorrhizal treated cowpea withstand the water stress and produced high yield. Biocontrol experiment had 2 kg sterilized soil potted into bags with cultivars IT90K-277-2 and IT06K123-1, fourteen treatments were established with soil drenched before planting and simultaneous inoculation. Soil drenched with AMF before planting and inoculation of M. phaseolina after 10 days of germination recorded higher growth parameters, while the simultaneous inoculated plant was the most effective in reducing disease severity. However, simultaneous treatment of G. deserticola, G. gigantea and M. phaseolina were most effective for both growth parameters and reduction of disease severity

Comparison of strains and feed withdrawal durations on growth, haematological indices and serum biochemistry of broiler chickens at finisher phase

The present investigation was undertaken to assess the response of two broiler strains in terms of growth, haematological and serum indices to different durations of feed withdrawal regimen at finisher phase. A total of 180 day-old broiler chicks comprising 90 chicks each of Arbor Acre and Ross 308 were sourced from reputable hatchery. The chicks on strain basis were distributed into three feed withdrawal durations: T1 (control), T2- morning (8am-12noon) and T3- afternoon (12noon – 4pm). Each of the treatment was replicated three times. Results showed the existence of significant (P<0.01) differences between the two strains in respect of body weight and linear measurements at 4th and 6th week. Ross 308 broilers in most cases recorded superior mean values than Arbor Acre. It means that the former has superior genetic make-up than the latter. Feed withdrawal durations also had significant effects on body weight and linear measurements. Full-fed birds had superior mean values than morning and afternoon fed birds in most of the traits measured. However, morning and afternoon fed birds recorded similar mean values. In addition, there was no significant (P>0.05) effect of strain and feed withdrawal on haematological and serum indices except total protein, cholesterol, creatinine and albumin. The obtained haematological mean values were within the recommended range, and this implies that birds reared under feed withdrawal regimen are safe and healthful for human consumption. Keywords: Strain, Arbor Acre, Ross 308, Haematology, fee