Increasing livestock depredation by recovering large carnivore populations undermines local support for long-term conservation. Past studies on livestock depredation have primarily focused on biophysical predictors, often overlooking the role of household-level husbandry and protection practices in shaping depredation risk. We used multivariate logistic regression models on a database of 1180 households (including 597 livestock depredation events) from the tropical lowlands of Nepal to identify predictors of livestock depredation by tigers (Panthera tigris tigris) and leopards (Panthera pardus). In line with previous research, models reported significant biophysical and livestock husbandry predictors of depredation risk, which are intrinsic geospatial and livelihood variables and unlikely to respond to interventions. In addition, we found novel evidence that the low-cost protection strategies of fixed night lighting and domestic dog ownership significantly lowered the odds of small livestock depredation. With careful implementation, these two mitigation measures have the potential to reduce livestock depredation risk and contribute to human–wildlife coexistence.
Tag: animal husbandry
Visit to NASC Museum: History of Agriculture
Symbiotic Nitrogen Fixation in Soil Contaminated with the Veterinary Antibiotics Oxytetracycline and Sulfamethazine
Veterinary and growth‐promoting antibiotics are widely used in animal husbandry and accumulate in manure‐fertilized soils. However, the impact of these antibiotics on symbiotic nitrogen fixation is poorly understood. We investigated the effect of the veterinary antibiotics oxytetracycline and sulfamethazine, and a combination of both, on nitrogen fixation in alfalfa (Medicago sativa L.) inoculated with Sinorhizobium meliloti. In a pot experiment, M. sativa was grown in soils fertilized with fresh manure that contained environmentally relevant antibiotic concentrations (0.2, 2, and 200 mg kg−1). Nodulation, nitrogen fixation, and nutrient concentrations were determined in the alfalfa plants and soils after 12 wk. Compared with the antibiotic‐free control, symbiotic nitrogen fixation increased significantly in soils mixed with manure containing 2 and 200 mg kg−1 oxytetracycline (20.1 and 20.8% increase, respectively) and a mixture of 200 mg kg−1 oxytetracycline and sulfamethazine (12.4% increase). The measured plant‐ and soil‐related parameters failed to explain the observed increase in nitrogen fixation. However, using concentration levels that accurately reflect common agricultural practices, we obtained results that directly contradict other experiments conducted under unrealistically high antibiotic concentrations.
Bioassay and enzymatic comparison of six entomopathogenic fungal isolates for virulence or toxicity against green peach aphids Myzus persicae
Myzus persicae is an economically important pest infecting more than 40 families of crops throughout the world. Six entomopathogenic fungal isolates, three each ofBeauveria bassiana and Verticillium lecanii, were screened for pathogenicity test against the M. persicae to select high virulent isolate with the most suitable application and to determine the role of individual enzyme in its virulence. Two treatments that is, conidial shower (190±23 conidia/mm2) and filtrate (3 ml filtrate per treatment from six days liquid broth culture of 1.0×108 conidia ml-1) were conducted for virulence or toxicity test and a comparison was made between treatments and among fungal isolates against the target pest. The percent mortality rates of filtrate at each day, after inoculation was found higher as compared to percent mortality of conidial showering.V. lecanii 3 showed highest virulence or toxicity against the target pest treated either with conidial (80.70%) or filtrate (88.36%) application while B. bassiana 70 and B. bassiana 76 showed high toxicity (77.14 and 80.86%, respectively) in filtrate application at 6th day of incubation. The aphidicial activities of the fungal isolates were evaluated by correlating the enzymes (Chitinase, protease and lipase) activities with enzymes production. On the basis of enzymatic activities, lipase was assumed to participate more in the total virulence or pathogenicity as compared to protease and chitinase while protease was assumed to participate more than chitinase. The pathogenicity test reveals the selection, effective application of most virulent isolate and the role of individual enzyme to develop an alternative control agent against M. persicae.
Fresh Phyllanthus emblica (Amla) Fruit Supplementation Enhances Milk Fatty Acid Profiles and the Antioxidant Capacities of Milk and Blood in Dairy Cows
The objective of this study was to investigate the effect of a diet supplemented with fresh amla fruit as a natural feed additive on blood metabolic parameters, milk antioxidant capacity, and milk fatty acid (FA) proportions in lactating dairy cows. Eight ruminally cannulated mid-lactation dairy cows were used in a repeated crossover design. The first group of four cows received total mixed ration (TMR) feed without fresh amla fruit (control group). The remaining four cows sequentially supplemented fresh amla fruit (FAF) at three levels (200, 400, then 600 g/d) (treatment group) at 14-day intervals. In second period, control and treatment groups were exchanged. The first ten days were adjusted to diet adaptation for each sub-period, and the last four days for sampling milk and blood. A total of 514 metabolites were detected from FAF using UPLC-ESI-MS/MS. The five main metabolites in FAF were phenolic acids (22%), flavonoids (20%), lipids (20%), amino acids and derivatives (9%), and tannins (7%). Amla fruit supplementation reduced total saturated fatty acid and the omega-6/omega-3 ratio at 200 or 400 g/d FAF dose compared to controls. In addition, amla fruit increased unsaturated FA, such as C20:5 (Eicosapentaenoic acid, EPA) and C22:6 (docosahexaenoic acid, DHA), and branched-chain FA in a dose-dependent manner at 200 or 400 g/d compared to controls. In addition, amla fruit increased the antioxidant capacity biomarkers in the blood, such as superoxide dismutase (SOD) and albumin; this confirms that amla fruit is an excellent antioxidant, inhibiting reactive oxygen species’ (ROS) metabolism, and can thereby protect cells from oxidative stress. Moreover, the most remarkable improvement of ferric reducing-antioxidant power (FRAP) and total antioxidant capacity (TAC) in milk was recorded at 400 g/d FAF doses compared to controls. Therefore, fresh amla fruit doses for lactating cows at 400 g/d on an as-fed basis can be used as an alternative additive feed in dairy cow diets to improve antioxidant capacity, protein efficiency, butter quality, and to produce more desirable milk fatty acid profiles for human consumption.
Will heat stress take its toll on milk production in China?
There are clear signs that milk production growth is leveling off, and recently even declining, in China. Heat stress is one of the main reasons for the recent reduction in milk production. In this study, we computed the change in milk production as a result of heat stress in major milk production areas in China. We constructed a temperature–humidity index (THI) spatial layer to understand the monthly distribution of heat and moisture. We documented specific areas in northern China where cattle were at high risk to heat stress in specific months. THI values exceeded the threshold above which milk production declines during months of June, July, and August. Especially during July, the THI value was higher than the production threshold in recent years (2008 to 2016) and in projected future scenarios (2050 and 2070). THI-based milk yield losses were up from 0.7 to about 4 kg per cow per day in July 2016. These losses are projected to increase from 1.5 to 6.5 kg in 2050 and 2 to 7.2 kg in 2070 (representing production losses between 15 and 50%). These results suggest that climate change will have significant consequences for the dairy sector in major milk-producing areas in China. Our results are useful in identifying areas susceptible to heat stress where adaptive livestock management practices are needed to prevent significant production decreases.