Assessment of short-term mortality of granary weevil,Sitophilus granarius (Coleoptera: Curculionidae) triggered by different microwave irradiation powers

Abstract

The insecticidal efficacy of microwave irradiation against the at 12, 24, 48 and 72?h following exposure to microwave irradiations (100, 300?W) and the progeny production was assessed 45?days later. Linearly increasing irradiation power range (100, 200 and 300?W) was set up for determining mortality tendency. An increase of insect mortality caused by higher irradiation period and times elapsed after treatment has become evident commencing from 12?h after the treatment, which has significantly decreased at later elapsed time after treatment. The irradiation periods inducing the highest mortality at the examined powers were at 10?min and at 100?W power (72?h: 64.93%) and at 4.5?min. and at 300?W power (12?h: 87.01). In addition, a complete suppression of progeny production was achieved by 4.5?min treatment at 300?W power. Lognormal-type mortality process was caused by the linearly increased irradiation range. The properly chosen microwave irradiation can be used for management of Sitophilus granarius larval and adult developmental stages. This treatment could provide an effective and friendly environmental treatment technique in Integrated Pest Management (IPM) program.     

Impact of sublethal di‐n‐butyl phthalate on the aquaculture fish species Nile tilapia (Oreochromis niloticus): histopathology and oxidative stress assessment

Phthalates such as di‐n‐butyl phthalate (DBP) and their esters are widely used plasticizers, their ubiquitous presence in daily life, inevitably leads to their restricted use due to important environmental pollution and health impacts and endocrine disruption potential. The aim of this study was to examine the effects of a sublethal concentration of 10 mg L^?1 DBP on haematocrit (HCT) values, gills and liver histology, malondialdehyde (MDA, 2‐thiobarbituric acid‐TBA reactivity) and reduced glutathione (GSH) levels in gills and liver tissue as oxidative stress biomarkers in the aquaculture fish species Nile tilapia (Oreochromis niloticus) after 24 (DBP‐24) and 96 (DBP‐96) h exposure. No differences were found between per cent HCT values in the 24 h exposure groups (P > 0.05). Response of antioxidant defence systems in liver and gill tissues of the fish were dependent on exposure duration and changed to a higher extent during 96 h. MDA levels in liver tissue increased in DBP treated fish in comparison to the control fish. However, the differences between the exposure and control groups were not significant (P > 0.05). A statistically significant decrease (P > 0.05) was recorded in gill MDA levels in the DBP‐96 group when compared to the control and DBP‐24 groups. The liver GSH levels were unchanged in the DBP treated fish. However, GSH levels were significantly lower in the gill tissue of the DBP‐96 group. Exposure to DBP caused several degenerative changes in the histology of gill and liver tissue. Gills displayed hyperaemia, epithelial lifting, oedema, talengiectasia, epithelial hyperplasia and fusion of secondary lamellae, whereas in liver several circulatory anomalies (hyperaemia, blood congestion and sinosoid dilatation) and vacuolization of hepatocytes were observed. Histopathological results demonstrated that the gills were more affected than the liver perhaps due to their direct contact with DBP.     

The Effect of Kefir as a Dietary Supplement on Nonspecific Immune Response and Disease Resistance in Juvenile Rainbow Trout,Oncorhynchus mykiss (Walbaum 1792)

In this study, juvenile rainbow trout fed with commercial pellets containing kefir provided increased nonspecific immune response and improved disease resistance against lactococcosis and yersiniosis. Kefir was used as a feed supplement at 2, 5, and 10% inclusion rates and several nonspecific immune parameters were observed at day(s) 1, 7, 14, 21, 28, and 35 following the treatment. A total of four experimental groups, including control, was established. The various parameters including hematocrits, nitroblue tetrazolium positive neutrophils, total leukocytes, serum lysozyme activity, total serum protein, and immunoglobulin M (IgM) levels were examined. As a result of this study, kefir‐fed fish had an increase in measured nonspecific immune parameters, especially in the group received the 10% kefir treatment. The challenged fish fed with kefir‐supplemented diet showed a better survival rate against Lactococcus garvieae than Yersinia ruckeri. Kefir supplementation reduced fish mortality significantly against L. garvieae.     

Parallelism in thermal growth response in otoliths and scales of brown trout (Salmo trutta L.) from alpine lakes independent of genetic background

Low density in natural populations of salmonids has predominantly been managed by stocking of non‐native conspecifics. Due partly to domestication, introduced non‐native fish may be maladapted under natural conditions. Interbreeding between introduced and wild individuals may therefore impair local adaptation and potentially population viability. Brown trout (Salmo trutta L.) from three headwaters (with stocked fish) and three interconnected lakes (with native fish) on the Hardangervidda mountain plateau, southern Norway, were tested for differences in thermal effects on scale and otolith growth. Otolith and scale annuli widths from immature brown trout showed positive correlation with mean annual summer temperature for all six sampled populations. In mature individuals, a similar positive thermal correlation was evident for the otoliths only. Interannuli width measurements from scales indicate a halt in somatic growth for brown trout in this alpine environment when reaching ages between 7 and 9 winters, coinciding with age at maturity. Our study indicates that otolith growth follows summer temperature even when individuals do not respond with somatic growth in these populations and that introduced brown trout and introgressed populations have similar thermal growth responses. Due to the continued otolith growth after stagnation in somatic growth and the impact of fluctuations in summer temperature, the utilisation of otolith annuli widths for back calculation of length at age should be treated with caution.     

Silage and haylage as forage in slow and fast-growing broilers – effects on performance in Campylobacter jejuni infected birds

ABSTRACT

1. This study investigated the effects of daily intake of silage or haylage on broiler production performance and organ development. Furthermore, effects of daily intake of Lactobacillus plantarum either via silage or by supplemented drinking water, on Campylobacter jejuni loads in faeces were studied.

2. To test this, a 42-d experiment using Ross 308 and a 63-d experiment with Rowan Rangers hybrids, were performed. Silage inoculated with L. plantarum strain 256 and haylage were fed in total mixed rations with mixtures of 85% of pellets and 15% of respective forage (DM-based weight). Feed intake (FI), forage intake, body weight (BW) and feed conversion ration (FCR) were monitored weekly. Mortality was recorded daily, and organ weights were registered at slaughter. Quantification of C. jejuni was performed by colony counts from faecal samples after culture on agar plates.

3. There was a negative effect of haylage on BW and FI in the fast-growing Ross 308 hybrid. Silage had a negative effect on BW only on week four and six. Water inoculated with L. plantarum 256 increased BW in the starter period. Interestingly, no significant adverse effect of forage inclusion was observed in the Rowan Ranger birds.

4. Relative weight of the emptied gizzard was higher in both Ross 308 and Rowan Ranger birds fed haylage and silage than in the control group. In Ross 308 birds, both forages significantly reased the relative weight of gizzard with digestive content when compared to birds fed solely pellets.

5. In both studies, higher consumption of silage than haylage was observed.

6. In conclusion, daily intake of L. plantarum 256 either via silage or supplemented in drinking water, was not effective in reducing the shedding of C. jejuni in either Ross 308 or Rowan Ranger hybrids at the end of the rearing period.     

Reduced high intensity training distance had no effect on VLa4 but attenuated heart rate response in 2-3-year-old Standardbred horses

Background

Training of Standardbred race horses aims to improve cardiovascular and metabolic functions but studies on the effects of different training strategies from breaking till racing are lacking. Sixteen horses with the goal to race as 3-year-olds were studied from breaking (1-year-olds) to December as 3-year-olds. Horses were allocated to either a control (C) or reduced (R) training program from 2 years of age. The aim was to evaluate the effect of reducing the distance of high intensity exercise by 30% with respect to velocity at lactate concentration 4 mmol/l (V_La4), blood lactate and cardiovascular response. All training sessions were documented and heart rate (HR) was recorded. A standardized exercise test of 1,600 m was performed 10 times and a V_La4 test was performed five times.

Results

C horses initially exercised for a longer time with a HR >180 beats per minute compared to R horses (P < 0.05) but after 6–9 months, time with HR >180 bpm decreased in C and were similar in the two groups (P > 0.05). Over the 2-year period, recovery HR after the 1,600 m-test decreased in both groups but was within 2 months lower in C than in R (P < 0.05). C horses also had lower resting HR as 3-year-olds (P < 0.01) than R horses. In C, post exercise hematocrit was higher than in R (P < 0.05). There was a tendency (P < 0.1) towards a larger aortic diameter in C as 3-year-olds (C: 1.75 ± 0.05, R: 1.70 ± 0.05 cm/100 kg BW). Left ventricle diameter and blood volume (in December as 2-year-olds) did not differ between groups. There were no differences between groups in post exercise blood lactate concentration or in V_La4. Both groups were equally successful in reaching the goal of participation in races.

Conclusions

Horses subjected to a reduced distance of high intensity training from the age of 2 showed an attenuated heart rate response, but were able to maintain the same V_La4 and race participation as horses subjected to longer training distances.     

Factors affecting costs for on-farm control of salmonella in Swedish dairy herds

Background

The Swedish control program for salmonella includes restrictions and on-farm control measures when salmonella is detected in a herd. Required control measures are subsidised by the government. This provides an opportunity to study costs for on-farm salmonella control. The aim of this study was to describe the costs for on-farm salmonella control in Swedish cattle herds and to investigate the effects of herd factors on these costs in dairy herds.

Results

During the 15 years studied there had been a total of 124 restriction periods in 118 cattle herds; 89 dairy herds, 28 specialised fattening herds and three suckler herds. The average costs per herd for on-farm salmonella control was 4.60 million SEK with a median of 1.06 million SEK corresponding to approximately 490 000 and 110 000 EUR. The range was 0.01 to 41 million SEK corresponding to 1080 EUR to 4.44 million EUR per farm. The costs cover measures required in herd-specific control plans, generally measures improving herd hygiene. A mixed linear model was used to investigate associations between herd factors and costs for on-farm salmonella control in dairy herds. Herd size and length of the restriction period were both significantly associated with costs for on-farm control of salmonella with larger herds and longer periods of restrictions leading to higher costs. Serotype detected and administrative changes in the Swedish Board of Agriculture aiming at reducing costs were not associated with costs for on-farm salmonella control.

Conclusions

On-farm control of salmonella in Swedish cattle herds incurred high costs but the costs also varied largely between herds. Larger herds and longer restriction periods increased the costs for on-farm control of salmonella in Swedish dairy herds. This causes concern for future costs for the Swedish salmonella control program as herd sizes are increasing.     

Information Needs of Non-industrial Private Forest Owners After Logging Operations in Finland: A Case Study

In this study, the information needs of non-industrial private forest owners in Finland, after logging operations, were investigated. The study was carried out as an online survey in 2017. The survey was targeted at non-industrial private forest owners who had sold their timber during the previous 10 years (2008–2017) and whose email addresses were in the customer relationship management system of a large wood procurement company in Finland. A response link for the survey was successfully sent to 31,988 forest owners, of whom 3323 replied (response rate: 10.4%). The final study data included 3284 non-industrial private forest owners. The results of the study, which need to be interpreted cautiously due to the low response rate, showed that the forest owners want better-quality reporting after logging operations. Furthermore, the results suggested that gender, age, education, occupational status, place of living, size of, and access to, forest property, and length of, and objectives for, forest ownership have a significant effect on their information needs. Younger, highly-educated, female, urban-living and multi-objective forest owners with larger forest holdings and short forest ownership tenures desired more information. Particularly, the respondents conveyed that they would like more and better information about thinning harvesting result. The results also indicated that when different groups of forest owners call for certain information, there is a need for producing different types of reports after logging operations for different forest owner segments.

     

Transformation of <Emphasis Type="Italic">Campanula</Emphasis> by wild type <Emphasis Type="Italic">Agrobacterium rhizogenes</Emphasis>

Compact growth is an important quality criterion in horticulture. Many Campanula species and cultivars exhibit elongated growth which is suppressed by chemical retardation and cultural practice during production to accommodate to the consumer’s desire. The production of compact plants via transformation with wild type Agrobacterium rhizogenes is an approach with great potential to produce plants that are non-GMO. Efficient transformation and regeneration procedures vary widely among both plant genera and species. Here we present a transformation protocol for Campanula. Hairy roots were produced on 26–90% of the petioles that were used for transformation of C. portenschlagiana (Cp), a C. takesimana × C. punctata hybrid (Chybr) and C. glomerata (Cg). Isolated hairy roots grew autonomously and vigorously without added hormones. The Cg hairy roots produced chlorophyll and generated plantlets in response to treatments with cytokinin (42 µM 2iP) and auxin (0.67 µM NAA). In contrast, regeneration attempts of transformed Cp and Chybr roots lead neither to the production of chlorophyll nor to the regeneration of shoots. Agropine A. rhizogenes strains integrate split T-DNA in T_L- and T_R-DNA fragments into the plant genome. In this study, regenerated plants of Cg did not contain T_R-DNA, indicating that a selective pressure against this T-DNA fragment may exist in Campanula.