scholarly journals Efficacy of Broilers as a Method of Face Fly (Musca autumnalis De Geer) Larva Control for Organic Dairy Production

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2429
Author(s):  
Hannah N. Phillips ◽  
Roger D. Moon ◽  
Ulrike S. Sorge ◽  
Bradley J. Heins
Keyword(s):  
Broiler Chickens ◽  
Survival Rates ◽  
Weather Conditions ◽  
Cow Dung ◽  
First Instar ◽  
Treatment Conditions ◽  
Organic Dairy ◽  
Outdoor Area ◽  
Musca Autumnalis ◽  
Organic Dairy Production

The objective of this study was to evaluate Freedom-Ranger broiler chickens as a method to control face fly (Musca autumnalis De Geer) larvae in cow dung pats on pasture. Ninety-nine pats in three replicates were inoculated with first-instar larvae and exposed to one of four treatment conditions for 3 to 4 days: (1) an environment-controlled greenhouse (GH); (2) pasture without broilers (NEG); (3) pasture with 25 broilers stocked at a low density of 2.5 m2 of outdoor area per broiler (LOW); and (4) pasture with 25 broilers stocked at a high density of 0.5 m2 of outdoor area per broiler (HIGH). Broiler behaviors and weather conditions were recorded twice daily. Survival rates of larvae (mean, 95% CI) were similar for pats in the NEG (4.4%, 2–9%), LOW (5.6%, 3–11%), and HIGH (3.2%, 2–7%) groups, and was greatest for larvae reared in the GH (54.4%, 36–72%) group compared to all other groups. The proportion of broilers observed pasture ranging was 14.0% (6–28%) but was negatively related to solar radiation. Broilers were never observed foraging in pats. Results indicate that use of broilers may not be an effective method for controlling larvae of dung pat breeding flies.

scholarly journals Predicting the effect of decompression sickness on survival following submarine tower escape

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Geoff A.M. Loveman ◽  
Joel J.E. Edney
Keyword(s):  
Subject Matter ◽  
Decompression Sickness ◽  
Survival Rates ◽  
Weather Conditions ◽  
Subject Matter Expert ◽  
Content Type ◽  
Probability Of Survival ◽  
Predicted Probability ◽  
Standard Probability ◽  
Current Advice

Purpose The purpose of the present study was the development of a methodology for translating predicted rates of decompression sickness (DCS), following tower escape from a sunken submarine, into predicted probability of survival, a more useful statistic for making operational decisions. Design/methodology/approach Predictions were made, using existing models, for the probabilities of a range of DCS symptoms following submarine tower escape. Subject matter expert estimates of the effect of these symptoms on a submariner’s ability to survive in benign weather conditions on the sea surface until rescued were combined with the likelihoods of the different symptoms occurring using standard probability theory. Plots were generated showing the dependence of predicted probability of survival following escape on the escape depth and the pressure within the stricken submarine. Findings Current advice on whether to attempt tower escape is based on avoiding rates of DCS above approximately 5%–10%. Consideration of predicted survival rates, based on subject matter expert opinion, suggests that the current advice might be considered as conservative in the distressed submarine scenario, as DCS rates of 10% are not anticipated to markedly affect survival rates. Originality/value According to the authors’ knowledge, this study represents the first attempt to quantify the effect of different DCS symptoms on the probability of survival in submarine tower escape.

An efficient technique for laboratory rearing of Simulium verecundum S. &J. (Diptera: Simuliidae)

1978 ◽  
Vol 56 (3) ◽  
pp. 507-510 ◽  
Author(s):  
M. H. Colbo ◽  
B. H. Thompson
Keyword(s):  
Larval Development ◽  
Fish Meal ◽  
Survival Rates ◽  
Tropical Fish ◽  
Efficient Technique ◽  
Laboratory Rearing ◽  
First Instar ◽  
Magnetic Stirring ◽  
The Mean

A series of 10 similar rearing vessels, each containing 500 ml of water circulated by a rotating magnetic stirring bar, was used to rear cohorts of 50 first-instar Simulium verecundum larvae to adults. Ground 'TETRA' tropical fish meal was used as food. The culture water was replaced daily to remove toxic nitrogenous products excreted by the larvae. In three experiments, the mean [Formula: see text] survival rates were 71.60 ± 3.19%, 81.73 ± 2.78%, and 66.60 ± 2.60%; larval development was reasonably synchronous and the median periods required for growth from first instar to adult were 25, 22, and 21 days.

scholarly journals Effects of shelter type, early environmental enrichment and weather conditions on free-range behaviour of slow-growing broiler chickens

animal ◽  
2017 ◽  
Vol 11 (6) ◽  
pp. 1046-1053 ◽  
Author(s):  
L.M. Stadig ◽  
T.B. Rodenburg ◽  
B. Ampe ◽  
B. Reubens ◽  
F.A.M. Tuyttens
Keyword(s):  
Broiler Chickens ◽  
Environmental Enrichment ◽  
Weather Conditions ◽  
Free Range ◽  
Slow Growing

Effect of free-range access, shelter type and weather conditions on free-range use and welfare of slow-growing broiler chickens

2017 ◽  
Vol 192 ◽  
pp. 15-23 ◽  
Author(s):  
Lisanne M. Stadig ◽  
T. Bas Rodenburg ◽  
Bart Ampe ◽  
Bert Reubens ◽  
Frank A.M. Tuyttens
Keyword(s):  
Broiler Chickens ◽  
Weather Conditions ◽  
Range Use ◽  
Free Range ◽  
Slow Growing

Effects of heat stress on the quality of Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae)

2014 ◽  
Vol 104 (5) ◽  
pp. 543-551 ◽  
Author(s):  
De S. Wang ◽  
Yu R. He ◽  
Wei Zhang ◽  
Xiao G. Nian ◽  
Tao Lin ◽  
...  
Keyword(s):  
Heat Stress ◽  
Developmental Stage ◽  
Life Table ◽  
Natural Enemy ◽  
Pupal Stage ◽  
Weather Conditions ◽  
Life Table Parameters ◽  
First Instar ◽  
Trichogrammatoidea Bactrae

AbstractTrichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae) is an important natural enemy of many species of lepidopterous pests. The effects of heat stress temperature (33, 36, and 39 °C), duration of exposure (2, 4, 6, and 8 h), and developmental stage during exposure (embryo-first instar larvae, second instar larvae, prepupae, and pupae) on the development and reproduction of parasitoid T. bactrae were investigated in the laboratory. When exposed to 39 °C for 8 h during pupal stage, only 19.90% adults emerged from host eggs, and more than 14% were deformed (wings were folded or incomplete). Parasitoid females exposed to 39 °C for 8 h as prepupae only lived for 1.45 days and parasitized about 23.5 host eggs. Moreover, life-table parameters of T. bactrae were also influenced by exposure to heat stress temperatures during each preimaginal developmental stage. Based on these results, we propose that T. bactrae is susceptible to high temperatures, especially at 39 °C. Thus, this parasitoid may be more effectively controlling lepidopterous pests during cooler weather conditions.

scholarly journals Organic dairy production based on rapeseed, rapeseed cake or cereals as supplement to silagead libitum

2004 ◽  
Vol 54 (2) ◽  
pp. 81-93 ◽  
Author(s):  
Lisbeth Mogensen ◽  
Klaus L. Ingvartsen ◽  
Troels Kristensen ◽  
Susanne Seested ◽  
Stig M. Thamsborg
Keyword(s):  
Dairy Production ◽  
Rapeseed Cake ◽  
Organic Dairy ◽  
Organic Dairy Production

scholarly journals The Red Harmful Plague in Times of Climate Change: Blooms of the Cyanobacterium Planktothrix rubescens Triggered by Stratification Dynamics and Irradiance

2021 ◽  
Vol 12 ◽  
Author(s):  
Deborah Knapp ◽  
Bieito Fernández Castro ◽  
Daniel Marty ◽  
Eugen Loher ◽  
Oliver Köster ◽  
...  
Keyword(s):  
Thermal Stratification ◽  
Survival Rates ◽  
Standing Stock ◽  
Keystone Species ◽  
Weather Conditions ◽  
High Survival ◽  
Negative Consequences ◽  
Planktothrix Rubescens ◽  
Water Column Stability ◽  
Long Term Study

Planktothrix rubescens is a harmful planktonic cyanobacterium, forming concentrated metalimnetic populations in deep oligo- and mesotrophic lakes, even after successful restoration. In Lake Zurich (Switzerland), P. rubescens emerged as a keystone species with annual mass developments since the 1970s. Its success was partly attributed to effects of lake warming, such as changes in thermal stratification and seasonal deep mixing. However, recent observations based on a biweekly monitoring campaign (2009–2020) revealed two massive breakdowns and striking seasonal oscillations of the population. Here, we disentangle positive from negative consequences of secular lake warming and annual variations in weather conditions on P. rubescens dynamics: (i) despite the high survival rates of overwintering populations (up to 25%) during three consecutive winters (2014–2016) of incomplete deep convective mixing, cyanobacterial regrowth during the following stratified season was moderate and not overshooting a distinct standing stock threshold. Moreover, we recorded a negative trend for annual population maxima and total population size, pointing to a potential nutrient limitation after a series of incomplete winter mixing. Thus, the predication of steadily increasing blooms of P. rubescens could not be confirmed for the last decade. (ii) The seasonal reestablishment of P. rubescens was strongly coupled with a timely formation of a stable metalimnion structure, where the first positive net growth in the following productive summer season was observed. The trigger for the vertical positioning of filaments within the metalimnion was irradiance and not maximal water column stability. Repetitive disruptions of the vernal metalimnion owing to unstable weather conditions, as in spring 2019, went in parallel with a massive breakdown of the standing stock and marginal regrowth during thermal stratification. (iii) Driven by light intensity, P. rubescens was entrained into the turbulent epilimnion in autumn, followed by a second peak in population growth. Thus, the typical bimodal growth pattern was still intact during the last decade. Our long-term study highlights the finely tuned interplay between climate-induced changes and variability of thermal stratification dynamics and physiological traits of P. rubescens, determining its survival in a mesotrophic temperate lake.

scholarly journals Overexpression of OsF3H modulates WBPH stress by alteration of phenylpropanoid pathway at a transcriptomic and metabolomic level in Oryza sativa

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rahmatullah Jan ◽  
Muhammad Aqil Khan ◽  
Sajjad Asaf ◽  
In-Jung Lee ◽  
Kyung-Min Kim
Keyword(s):  
Survival Rates ◽  
Rice Cultivar ◽  
Phenylpropanoid Pathway ◽  
Wild Type ◽  
Flavonoid Pathway ◽  
First Instar ◽  
Physiological Pathways ◽  
Metabolomic Level ◽  
Whitebacked Planthopper ◽  
Related Proteins

Abstract The whitebacked planthopper (WBPH), has become a devastating pest for rice crops, causes serious yield losses each year, and urgently needs biological control. Here, we developed a WBPH-resistant rice cultivar by overexpressing the OsF3H gene. A genetic functional analysis of the OsF3H gene confirmed its role in facilitating flavonoid contents and have indicated that the expression of the OsF3H gene is involved in regulation of the downstream genes (OsDFR and OsFLS) of the flavonoid pathway and genes (OsSLR1 and OsWRKY13) involved in other physiological pathways. OxF3H (OsF3H transgenic) plants accumulated significant amounts of the flavonols kaempferol (Kr) and quercetin (Qu) and the anthocyanins delphinidin and cyanidin, compared to the wild type, in response to the stress induced by WBPH. Similarly, OsF3H-related proteins were significantly expressed in OxF3H lines after WBPH infestation. The present study, indicated that the regulation of JA in OxF3H plants was suppressed due the overexpression of the OsF3H gene, which induced the expression of downstream genes related to anthocyanin. Similarly, the OsWRKY13 transcriptional factor was significantly suppressed in OxF3H plants during WBPH infestation. Exogenous application of Kr and Qu increased the survival rates of susceptible TN1 lines in response to WBPH, while decreased the survival rate of first instar WBPHs, indicating that both flavonols exhibit pesticide activity. Phenotypic demonstration also affirms that OxF3H plants show strong resistance to WBPH compared with wild type. Collectively, our result suggested that OsF3H overexpression led to the up-regulation of defense related genes and enhanced rice resistance to WBPH infestation.

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