Six iso-nitrogenous (350 g protein kg⁻¹) and iso-caloric (4100 kcal kg⁻¹) diets with or without probiotics supplementation namely T₁ (Basal feed (BF) without probiotics; control), T₂ (BF + Bacillus subtilis and Lactococcus lactis), T₃ (BF + L. lactis and Saccharomyces cerevisiae), T₄ (BF + B. subtilis and S. cerevisiae), T₅ (BF + B. subtilis, L. lactis and S. cerevisiae) and T₆ (BF + heat-killed bacteria of B. subtilis, L. lactis and S. cerevisiae) were fed to Labeo rohita fingerlings (6.0 ± 0.06 g) for 60 days in triplicate tanks (30 fish per tank). In all probiotic-supplemented diets, the probiotic concentration was maintained at 10¹¹ cfu kg⁻¹ feed. After 60 days of culture, the fish fed combination of three probiotics at equal proportion (T₅) had higher (P < 0.05) growth, protein efficiency ratio, nutrient retention and digestibility and lower (P > 0.05) feed conversion ratio over other treatment groups. Total heterotrophic bacterial population in intestine was drastically reduced on 15th and 30th days of sampling than the initial value (0 day of sampling) for T₃, T₄ and T₅ groups. Except T₆, the gut colonization of respective probiotics, which were supplemented through the diets, was also increased up to 30 days of culture of fish and thereafter remained constant.

Probiotics play an important role in growth increment, immune enhancement and stress mitigation in fish. Increasing temperature is a major concern in present aquaculture practices as it markedly deteriorates the health condition and reduces the growth in fish. In order to explore the possibilities of using probiotics as a counter measure for temperature associated problems, a 30 days feeding trial was conducted to study the hemato-immunological and apoptosis response of Labeo rohita (8.3±0.4 g) reared at different water temperatures, fed with or without dietary supplementation of a probiotic mixture (PM) consisting of Bacillus subtilis, Lactococcus lactis and Saccharomyces cerevisiae) (10¹¹ cfu kg⁻¹). Three hundred and sixty fish were randomly distributed into eight treatment groups in triplicates, namely, T1(28°C+BF(Basal feed)+PM), T2(31°C+BF+PM), T3(34°C+BF+PM), T4(37°C+BF+PM), T5(28°C+BF), T6(31°C+BF), T7(34°C+BF) and T8(37°C+BF). A significant increase (P<0.01) in weight gain percentage was observed in the probiotic fed fish even when reared at higher water temperature (34–37°C). Respiratory burst assay, blood glucose, erythrocyte count, total serum protein, albumin, alkaline phosphatase and acid phosphatase were significantly higher (P<0.01) in the probiotic fed groups compared to the non-probiotic fed groups. A significant (P<0.01) effect of rearing temperature and dietary probiotic mixture on serum myeloperoxidase activity, HSP70 level and immunoglobulin production was observed. Degree of apoptosis in different tissues was also significantly reduced in probiotic-supplemented groups. Hence, the present results show that a dietary PM could be beneficial in enhancing the immune status of the fish and also help in combating the stress caused to the organism by higher rearing water temperature.

As a new class of agricultural insecticides, synthetic pyrethroids are widely used to control insect pests. Synthetic pyrethroids have been shown to enter the aquatic environment from agricultural runoff or drift from aerial and ground-based spraying applications posing threat to fishes which are less tolerant to pesticides through direct exposure. These insecticides interfere with the sodium channel of the nervous system resulting in prolonged sodium tail current. Widespread application of these chemicals has warranted the attention of the ecologist to understand the impact of these chemicals on the aquatic environment. In this perspective, an updated account of toxicological evaluation of three type II synthetic pyrethroids, viz. deltamethrin, cypermethrin and fenvalerate in terms of their physico-chemical, metabolic, hematological, histological, behavioral and reproductive aspects with respect to the fishes has been presented which may be useful for policy makers, academics, environmental scientists and agricultural professionals needing ready access to this information. The aim of the present synoptic literature appraisal was to summarize the main effect of current use, type II synthetic pyrethroids (deltamethrin, cypermethrin and fenvalerate) on aquatic environment due to their persistence and accumulation. This article will focus on non-target organisms in inland fresh water environment with special reference to fin fishes and will critically evaluate the toxicity of these pyrethroids in terms of growth inhibition, metabolic disorders, neurotoxicity, reproductive failure, enzymatic dysfunction, haematological alterations, and tissue damages. The rationalized information in this milieu may be useful in ecological risk evaluation and human health management as fish serves as an important bio-indicator for aquatic systems health.

Due to complexity of smallholder farms, many times technologies with great potential fail to achieve the desired impact in leveraging productivity and profitability of the farming community. In the Indo-Gangetic Plains there is an urgent need to understand the diversity of farm households, identifying the main drivers deciding their system thus, classifying them into homogenous groups. In the present study, the diversity of smallholder farms was assessed using crop, livestock and income related characteristics and associated farm mechanization. Using principal component analysis and cluster analysis for 252 farm households, 4 farm types were identified i.e. Type 1. Small Farm households with cereal-based cropping system and subsistence livestock (39%), Type 2. Small Farm households with diversified cropping system dominated by cereal and fodder crops with only cattle herd (9%), Type 3. Marginal Farm household with diversified cropping system dominated by cash crop and herd comprising of only cattle (39%), Type 4. Marginal Farm household with diversified cropping system dominated by cereal crops and herd dominated by small ruminants (12%). Based on the constraints identified for different components of farming systems, low-cost interventions were planned for each farm type. These interventions have resulted in 84.8–103.2 per cent increase in the income of the farm HH under study suggesting usefulness of typology-based intervention planning in increasing income of small farm holders.