Changes in Mithun (Bos frontalis) spermatozoa during epididymal passage

Genital organs of 10 healthy, adult Mithun bulls (6-8 years old) that were slaughtered at the dwellings of tribal people for meat were collected. Immediately after collection, spermatozoa from 3 different regions of the epididymis, i.e. the head, body and tail, were obtained to study morphological changes of the spermatozoa during passage through these regions. The prevalence of proximal cytoplasmic droplets significantly decreased from the head to the tail of the epididymis. Conversely, the percentage of distal cytoplasmic droplets increased significantly from the head to the tail region. The incidence of tailless heads rose significantly from head to body and then reduced significantly in the tail region. The percentage of total head abnormalities did, however, not change markedly, but total mid-piece and tail abnormalities differed significantly between the three epididymal regions.     

孟加拉吉大港山区Khagraohari的现代和传统农业系统中土壤化学性质

Land degradation in Chittagong hill tracts has been taking place due to shrinkage of forest cover, policy weakness, population explosion, and inappropriate hill farming system. Modern farming system in the Chittagong hill tracts like Sloping Agricultural Land Technology (SALT) is practiced to provide a new strategy for developing lands for economic productivity and bio-diversity conservation through establishment of ecological community rather than traditional shifting cultivation which is no longer sustainable according to the carrying capacity of ecosystem of Chittagong hill tracts. This study is to find out changing trends of soil chemical properties of sites under modern and traditional farming systems at Khagrachari district of Chittagong hill tracts. The result of the research shows that Sloping Agricultural Land Technology has significantly higher capacity of production due to the presence of the highest percentage of organic carbon, organic matter, compared with shifting cultivated site. The study recommends that shifting cultivation may be changed into a relatively stable semi-permanent farming system through developing participatory integrated farming systems to establish stable production environment in the Chittagong Hill Tracts.     

Phytochemical investigation and in vitro antinociceptive activity of Clerodendrum indicum leaves

The crude ethanolic extracts of Clerodendrum indicum Linn. leaves were investigated for possible antinociceptive activity using acetic acid induced writhing model in mice. Phytochemical analysis was also carried out according to the standard procedures to identify the presence of different phytoconstituents in the ethanolic extract of the plant leaves. The study results showed 38.91 and 55.24% inhibition of writhings in the tested mice when ethanolic extract of Clerodendrum indicum Linn. leaves at doses of 250 and 500 mg kg(-1) body weight was given intraperitoneally, respectively. The study results were also compared with antinociceptive activity of the standard drug, Diclofenac sodium (68.37% inhibition) used at 25 mg kg(-1) body weight. At the above doses, the crude ethanolic extract of the plant showed significant antinociceptive activity in dose dependent fashion in acetic acid-induced writhing model in mice. The inhibition of writhings was calculated in respective to control group and it was found that p-values (<0.0001) obtained in all cases were extremely statistically significant. However, the phytochemical analysis showed the presence of alkaloid, steroid, saponin, tannin, reducing sugar and gum. The results suggest that crude ethanolic extracts of Clerodendrum indicum leaves possess significant antinociceptive properties justifying its folkloric use as analgesics and further research is necessary to isolate the principle phytochemical constituent(s) responsible for this activity.     

Slow wilting components in pigeonpea (<Emphasis Type="Italic">Cajanus cajan</Emphasis>(L.) Millsp.)

Partial resistance to Fusarium wilt was characterized based on root inoculation on seven pigeonpea genotypes with a virulent isolate of Fusarium udum. Resistance to wilt seems to be mainly due to localization of the pathogen in roots and vascular systems in the stem. Three components of resistance (wilting rate or incubation period, weighted wilt index and number of colonized plants) were determined and compared to those of susceptible genotypes Bahar and TTB7. There were significant differences between the genotypes for the resistance components. The mechanisms of resistance in the genotypes appeared to be different, with genotype ICP8863, having a longer incubation period, minimum wilt index and minimum pathogen colonization as compared to other resistant genotypes (ICP9174, ICP87119 and ICP8858). Wilting rate or incubation period and number of colonized plant were significantly correlated with resistance in adult plants in the field (AUDPC). Wilt index was useful in discriminating between genotypes that had a similar incubation period and number of colonized plants. The partial character of resistance is probably based on quantitative differences in localization capacity among the genotypes. A quantitative relationship between components, incubation period and number of colonized plants and the AUDPC, if verified for a large number of genotypes, may be used to obtain an index of resistance that may predict resistance levels in the field.     

Annually twice induced spawnings provide multiple benefits: Experimental evidence from an Indian major carp (Catla catla,Hamilton 1822)

Multiple spawnings are special reproductive tactics that many fish evolved to obtain different types of direct and/or indirect spawning benefits. This has led to two pertinent questions: (a) what types of benefit does a commercially important fish provide during multiple induced spawnings annually? and (b) is there any trade‐off between traits during these spawnings? To address these questions, the present study was carried out with two separate experiments during two spawning events of an Indian major carp (Catla catla) to assess: (a) male's spawning performances and (b) female's spawning performances. The male's spawning data revealed that they produced significantly higher amount of milt and hatchlings during the first spawning, while they significantly reduced hatchling deformation rate, enhanced offspring survival rate and enlarged offspring body size during the second spawning. The female's spawning information unveiled no significant differences in total egg weight, hatching rate and hatchling deformation rate between the first and second spawning. However, females had significantly higher offspring survival rate during the first spawning and enhanced offspring body size during the second spawning. Interestingly, the analysis of trait associations revealed that males allocated energy with a trade‐off between milt weight and offspring survival rate, whereas females showed a trade‐off between hatching rate and offspring survival rate. Thus, the study provides some important information for carp breeders and associated stakeholders to know which spawning season is preferable for the higher production of eggs, milt and good quality larvae.     

The role of gape‐limitation in intraguild predation between endangered Mohave tui chub and non‐native western mosquitofish

Intraguild predation (IGP) is a mechanism that may facilitate the co‐existence of native species with non‐native invasive species. We conducted laboratory predation trials to assess the role of predator gape‐limitation in the context of IGP between the endangered Mohave tui chub (Siphateles bicolor mohavensis) and invasive western mosquitofish (Gambusia affinis). Larval tui chubs had significantly lower (χ² = 74.74; P < 0.001) survival in the presence of female mosquitofish (10.0%) than in the presence of male mosquitofish (73.3%). Reciprocally, adult tui chubs preyed upon adult mosquitofish, causing a significantly lower (χ² = 11.33; P < 0.001) survival for male mosquitofish (60%) compared to female mosquitofish survival (96.7%). Vulnerability modelling revealed that mosquitofish with a body depth < 4.6 mm and a larval tui chub with a body depth < 1.2 mm were completely vulnerable to predation by adult Mohave tui chub and adult mosquitofish, respectively. IGP in this study system is size‐structured based on gape‐size limitation and may have some conservation implications for the recovery of endangered Mohave tui chub. Our findings also provide an important caveat to the dogmatic view of mosquitofish as a threat whenever they invade. It is important to note that many previous studies that reported negative impacts of mosquitofish involved native species with relatively small body sizes, often the same size as mosquitofish.     

Distillery effluents effect on soil organic carbon and aggregate stability of a Vertisol in India

Distillery effluent, a waste by-product of distillery industries, is usually applied to arable land near the distilleries as irrigation water or as a soil amendment. To evaluate the effect of distillery effluent, both spent wash (SW) and post-methanated effluent (PME), on soil organic carbon and aggregate stability, a field experiment on a soybean (Glysine max L.)–wheat (Triticum aestivum L.) system was conducted for five years on a Vertisol of central India. The treatments were control (no fertilizer or manure or SW or PME, T₁), 100% NPK + farmyard manure (FYM) @ 4 Mg ha⁻¹ to soybean (T₂), four graded levels of SW, viz., 2.5 cm SW to soybean and none to wheat (T₃), 2.5 cm SW to soybean and 1.25 cm to wheat (T₄), 5 cm SW to soybean and none to wheat (T₅), 5 cm SW to soybean and 2.5 cm to wheat (T₆), and four graded levels of PME, viz., 2.5 cm PME to soybean and none to wheat (T₇), 2.5 cm PME to soybean and 1.25 cm to wheat (T₈), 5 cm PME to soybean and none to wheat (T₉), 5 cm PME to soybean and 2.5 cm to wheat (T₁₀). The organic carbon of the surface (0–15 cm) soil that received either PME or SW (treatments T₃–T₁₀), was significantly (P < 0.05) higher than in treatments T₁ and T₂. The mean weight diameter (MWD) of water stable aggregates in this soil layer was also significantly higher in treatments T₃–T₁₀, compared with T₁ and T₂. The MWD showed a positive linear relationship with the organic carbon content of the soil (R² = 0.54**). The proportion of macro-aggregates was higher in SW treated plots than PME, no distillery effluents and NPK + FYM treatments. However, the micro-aggregates showed the reverse trend. The macro-aggregate-associated carbon was higher in SW treated plots. It was highest in T₆ and lowest in T₁. The plots receiving the PME and SW showed increased soil organic carbon, MWD, percentage macro- and micro-aggregate-associated carbon than T₁ and T₂. Application of distillery effluents increased the aggregate stability of the Vertisol through enhanced soil organic carbon as well as the aggregate-associated carbon. So application of SW or PME could be a viable option for soil aggregate stability and enhanced productivity.     

Effect of higher levels of dietary selenium on production performance and immune responses in growing Japanese quail

1. The effect of increasing dietary selenium (Se) on production performance and immune responses in growing (0 to 6 weeks) Japanese quail was investigated. 2. One-day-old chicks (240) were randomly selected and divided into 12 groups with 20 chicks in each group (3 dietary treatments x 4 replicates). The basal diet contained 0.2 mg Se/kg and the two experimental diets were supplemented with 0.5 and 1.0 mg Se/kg. 3. Body weight gain, food intake and food conversion ratio and mortality were not affected by Se supplementation. 4. On d 28, antibody responses to inoculated sheep red blood cells were determined. Antibody titres were significantly higher after feeding the two Se-supplemented diets. 5. During week 4, the response to intradermally injected phytohaemagglutinin, an index of the in vivo cell-mediated immune response, was shown to be increased in the groups fed on the Se-supplemented diets. 6. After 6 weeks, the relative weights of the bursa of Fabricius and thymus were greater in the chicks given the Se-supplemented diets but there was no effect on the relative weight of spleen and liver. 7. It is concluded that supplementing the diet with Se has a beneficial effect on immune responses but does not affect production performance in growing Japanese quail.     

Suppressing methane emission and global warming potential from rice fields through intermittent drainage and green biomass amendment

Winter cover crops are recommended to improve soil quality and carbon sequestration, although their use as green manure can significantly increase methane (CH₄) emission from paddy soils. Soil management practices can be used to reduce CH₄ emission from paddy soils, but intermittent drainage is regarded as a key practice to reduce CH₄ emission and global warming potential (GWP). However, significantly greater emissions of carbon dioxide (CO₂) and nitrous oxide (N₂O) are expected when large amounts of cover crop biomass are incorporated into soils. In this study, we investigated the effects of midseason drainage on CH₄ emission and GWP following incorporation of 0, 3, 6 and 12 Mg/ha of cover crop biomass. Methane, CO₂ and N₂O emission rates significantly (P < 0.05) increased with higher rates of cover crop biomass incorporation under both irrigation conditions. However, intermittent drainage effectively reduced seasonal CH₄ fluxes by ca. 42–46% and GWP by 17–31% compared to continuous flooding. Moreover, there were no significant differences in rice yield between the two water management practices with similar biomass incorporation rates. In conclusion, intermittent drainage and incorporation of 3 Mg/ha of green biomass could be a good management option to reduce GWP.