Determinants of adoption behaviour of the fish farmers of Pabda fish culture (Ompok bimaculatus Bloch, 1794) in Tripura,Northeast India

Aquaculture International - Most of the adoption studies in catfish culture were restricted to feeding habits, growth rate and morphological studies, neglecting the social factors and adoption of...     

Effect of probiotic on reproductive performance in female livebearing ornamental fish

A probiotic bacterial strain, Bacillus subtilis, isolated from the intestine of Cirrhinus mrigala (Hamilton), was incorporated in fish feed at four different concentrations (5 × 10⁸ cells g⁻², 5 × 10⁷ cells g⁻², 5 × 10⁶cells g⁻¹ and 5 × 10⁵ cells g⁻¹) and fed to four species of livebearing ornamental fish, Poecilia reticulata (Peters), Poecilia sphenops (Valenciennes), Xiphophorus helleri (Heckel) and Xiphophorus maculatus (Gunther) for one year duration to observe the effect of dietary probiotic supplementation on their reproductive performance. Sixty virgin females of each species were stocked separately in circular FRP tanks (350 L) and fed diets with varying levels of probiotic cells and control feed. Broodstock performance was evaluated based on gonadosomatic index (GSI), fecundity and fry production of female broodstock. The results showed that supplementation of feed with probiotics increased significantly (P<0.05) the GSI, fecundity and fry production of spawning females and length and weight of fry in all the four species of fish. The number of dead and deformed fry were also significantly lower (P<0.05) in fish fed with the probiotic feeds. The use of higher concentration of the probiont in diet did not always lead to significantly improved reproductive performance of the spawners. Collectively, this study showed that female livebearers benefit from inclusion of probiotics in diet during their reproductive stages.     

Preparation and characterization of papain-modified sesame (Sesamum indicum L.) protein isolates

Defatted sesame meal ( approximately 40-50% protein content) is very important as a protein source for human consumption due to the presence of sulfur-containing amino acids, mainly methionine. Sesame protein isolate (SPI) is produced from dehulled, defatted sesame meal and used as a starting material to produce protein hydrolysate by papain. Protein solubility at different pH values, emulsifying properties in terms of emulsion activity index (EAI) and emulsion stability index (ESI), foaming properties in terms of foam capacity (FC) and foam stability (FS), and molecular weight distribution of the SPI hydrolysates were investigated. Within 10 min of hydrolysis, the maximum cleavage of peptide bonds occurred as observed from the degree of hydrolysis. Protein hydrolysates have better functional properties than the original SPI. Significant increase in protein solubility, EAI, and ESI were observed. The greatest increase in solubility was observed between pH 5.0 and 7.0. The molecular weight of the hydrolysates was also reduced significantly during hydrolysis. These improved functional properties of different protein hydrolysates would make them useful products, especially in the food, pharmaceutical, and related industries.     

Nitrous oxide emissions from kharif and rabi legumes grown on an alluvial soil

Nitrous oxide (N₂O) emissions were monitored for a period of 60 days in a pot culture study, from two kharif (June-September) and two rabi (October-March) season legumes, which were grown on a Typic Ustochrept, alluvial sandy loam soil. Black gram (Vigna mungo L. Hepper), var. T-9, and soybean (Glycine max L. Merril), var. Punjab 1, were taken up in kharif season whereas lentil (Lens esculenta Moench), var. JLS-1, and Bengal gram (Cicer arietinum L.), var. BGD-86, were grown in rabi season. All the crops were grown with and without urea and one pot (containing soil but with no fertilizer or crop) was used as a control. Nitrous oxide emissions were significantly higher in unfertilized cropped soil than in the control, while the addition of urea to the crops further increased the emissions. Significant emissions occurred during third and seventh week after sowing for all the treatments in both kharif and rabi seasons. In kharif, soil cropped with soybean had higher total N₂O-N emission than soil sown with black gram both under fertilized and unfertilized conditions; while in rabi, lentil had a higher total N₂O-N emission than Bengal gram under both fertilized and unfertilized conditions. In kharif, total N₂O-N emissions ranged from 0.53 (control) to 3.84 kg ha^-1 (soybean+urea), while in rabi it ranged from 0.45 (control) to 3.06 kg ha^-1 (lentil+urea). Higher N₂O-N emissions in kharif than in rabi was probably due to the favorable effect of temperature on nitrification and denitrification in the former season. The results of the study indicated that legume crops may lead to an increase in N₂O formation and emission from soils, the extent of which varies from crop to crop.     

Performance of crossbred calves with dietary supplementation of garlic extract

Twelve crossbred calves (Holstein cross) in their pre-ruminant stage were used to study the effect of garlic extract feeding on their performance and they were randomly allotted into treatment and control groups in equal number. Performance was evaluated by measuring average body weight (BW) gain, feed intake [dry matter (DM); total digestible nutrient (TDN) and crude protein (CP)], feed conversion efficiency (DM, TDN and CP), fecal score and fecal coliform count. Diets were same for both groups. In addition, treatment group received garlic extract supplementation at 250 mg/kg BW/day/calf. BW measured weekly, feed intake measured twice daily, proximate analysis of feeds and fodders analysed weekly, fecal scores monitored daily and fecal coliform count done weekly. There was a significant (p < 0.01) increase in mean BW gain and feed intake and a significant (p < 0.01) decrease in severity of scours as measured by fecal score in the treatment group compared to the control group. The results suggest that garlic extract can be supplemented to the calves for better performance.     

Adrenocortical Interactions following Dehydration, Sodium chloride, Potassium chloride, Cortisone acetate and Desoxycorticosterone acetate Treatments in the Parakeet, Quail and Myna

Dehydration results in an extreme hypertrophy and hyperplasia of the adrenocortical tissue, whereas NaCl produces a profound atrophic change. KCl brings the gland to some hypertrophy in parakeet and myna, but to some atrophy in quail. The response to cortisone and desoxycorticosterone acetate clearly indicates an atrophic look in quail and myna, however, in parakeet both the subcapsular and the central zones respond uniformly towards hypertrophy. No specific zonal responses could be detected even in cases with a histomorphological zonation. This may be due to the hormonal situation discussed by other authors.     

Determination of Critical Tissue Phosphorus Concentration in Mungbean and Urdbean for Plant Diagnostics

A pot experiment was conducted to study the effect of phosphorus (P) nutrition on mungbean and urdbean genotypes and to determine the critical concentration of tissue phosphorus at different growth stages for plant diagonostic and P management. There were eight treatments consisting of different levels of P added in the form of monopotassium phosphate (KH₂PO₄). Destructive plant samples were taken to determine tissue P concentration and plant dry matter at different growth stages. Plant tissue P concentration was found highly correlated with dry matter production in mungbean (r² = 0.84–0.98) and urdbean (r² = 0.98–0.998) at corresponding sampling period throughout the growth stages. Considerable variation was observed in critical P concentration with genotypes and leaf position in mungbean and urdbean. Critical P concentration varied between 0.45–0.49 in mungbean and 0.45 to 0.57 in urdbean at early stages of crop growth, and these values declined sharply with advancement in crop growth.     

Performance of larval parasitoid,Bracon brevicornis on two Spodoptera hosts: implication in bio-control of Spodoptera frugiperda

Successful pest management using parasitoids requires careful evaluation of host-parasitoid interactions. Here, we report the performance of larval ecto-parasitoid wasp, Bracon brevicornis (Wesmael) on important agricultural pests, Spodoptera litura (Fabricius) and S. frugiperda (J.E. Smith). Biology of B. brevicornis was studied on different host instars under laboratory and cage setup. In no-choice assay, the parasitoid development was highest on fifth-instar S. litura larvae as the wasp laid?~?253 eggs with 62% hatching, 76% pupae formation and 78% adult emergence. Similarly, these parameters were highest on fifth instar S. frugiperda larvae (293 eggs, 57% hatching, 80% pupae formation, 70% adult emergence). In two-choice assay, B. brevicornis preferred fourth or fifth over third instar larvae of both hosts. Successful parasitism depends on host paralysis and suppression of host immunity. B. brevicornis interaction downregulated cellular immunity of both hosts as shown by reduced hemocyte viability and spreading. The percent parasitism rate of B. brevicornis was unaltered in the presence of host plant, Zea mays in cage study. 76 and 84% parasitism was observed on fifth-instar larvae of S. litura and S. frugiperda, respectively. We evaluated the performance of B. brevicornis as a biocontrol agent on S. frugiperda in maize field. Our results show 54% average reduction in infestation after release of B. brevicornis. Taken together, we report the performance of B. brevicornis on important insect pests for the first time in laboratory and field conditions. Our findings indicate that B. brevicornis is a promising candidate for integrated pest management.