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1.
J Econ Entomol ; 109(4): 1859-71, 2016 08.
Article in English | MEDLINE | ID: mdl-27329627

ABSTRACT

Blended refuge for transgenic plants expressing Bacillus thuringiensis (Bt) toxins has been approved in the northern United States as a resistance management strategy alternative to a structured refuge. A three-year study (2012-2014) was conducted with 54 trials across nine states in the southern United States to evaluate plant injury from lepidopteran pests of corn and yield in a corn hybrid expressing Cry1F × Cry1Ab × Vip3Aa20 (Pioneer Brand Optimum Leptra) planted as a pure stand and in refuge blends of 5, 10, and 20% in both early and late plantings. Injury by corn earworm, Helicoverpa zea Boddie (Lepidoptera: Noctuidae), and fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), was generally proportional to the percentage of non-Bt corn within each refuge blend. Across locations, ear injury in plots with 100% Cry1F × Cry1Ab × Vip3Aa20 (Optimum Leptra) corn ranged from no injury to a maximum of 0.42 cm(2) per ear in Mississippi in 2013. Leaf injury ratings in 100% non-Bt plots in early and late planted trials in 2014 were 86- and 70-fold greater than in 100% Cry1F × Cry1Ab × Vip3Aa20 (Optimum Leptra) plots. Plants in plots with blended refuges had significantly greater leaf injury in 2012 (5, 10, and 20% refuge blends), in the early-planted corn in 2013 (10 and 20% only), and in both early- and late-planted corn in 2014 (20% only) as compared with leaf injury in a pure stand of Cry1F × Cry1Ab × Vip3Aa20 (Optimum Leptra) seen during these years. Corn ears in plots with blended refuges also had significantly greater area of kernels injured in 2012 (5, 10, and 20%), in early- and late-planted corn in 2013 (5, 10, and 20%), and in early (10 and 20% only)- and late-planted corn (5, 10, and 20%) in 2014 as compared with ear injury in a pure stand of Cry1F × Cry1Ab × Vip3Aa20 (Optimum Leptra) seen during these years. Infestations of southwestern corn borer, Diatraea grandiosella Dyar (Lepidoptera: Crambidae), were also significantly reduced by Cry1F × Cry1Ab × Vip3Aa20 (Optimum Leptra). Despite these differences in injury, yield averaged across locations varied among refuge blends only in the late-planted trials in 2013, with greater yields in the 0% refuge blend than in the 20% blend; however, when examining yield separately by location, only two of nine locations had higher yields in the 100% Bt plots than in any of the blended refuge plots. As a complement to studying the contribution of blended refuge to delaying resistance, quantifying injury and yield in a range of refuge blends is a necessary step to provide management information on the range of lepidopteran pests that occur in the southern United States.


Subject(s)
Bacillus thuringiensis/chemistry , Bacterial Proteins/pharmacology , Bacterial Toxins/pharmacology , Moths/physiology , Zea mays/physiology , Animals , Bacillus thuringiensis/genetics , Insecticide Resistance , Pest Control, Biological , United States , Zea mays/genetics , Zea mays/growth & development
2.
J Econ Entomol ; 108(1): 157-65, 2015 Feb.
Article in English | MEDLINE | ID: mdl-26470116

ABSTRACT

Fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae); corn earworm, Helicoverpa zea Boddie (Lepidoptera: Noctuidae); southwestern corn borer, Diatraea grandiosella Dyar (Lepidoptera: Crambidae); sugarcane borer, Diatraea saccharalis F. (Lepidoptera: Crambidae); and lesser cornstalk borer, Elasmopalpus lignosellus Zeller (Lepidoptera: Pyralidae), are lepidopteran pests of corn, Zea mays L., in the southern United States. Blended refuge for transgenic plants expressing the insecticidal protein derivative from Bacillus thuringiensis (Bt) has recently been approved as an alternative resistance management strategy in the northern United States. We conducted a two-year study with 39 experiments across 12 states in the southern United States to evaluate plant injury from these five species of Lepidoptera to corn expressing Cry1F and Cry1Ab, as both single and pyramided traits, a pyramid of Cry1Ab×Vip3Aa20, and a pyramid of Cry1F×Cry1Ab plus non-Bt in a blended refuge. Leaf injury and kernel damage from corn earworm and fall armyworm, and stalking tunneling by southwestern corn borer, were similar in Cry1F×Cry1Ab plants compared with the Cry1F×Cry1Ab plus non-Bt blended refuge averaged across five-plant clusters. When measured on an individual plant basis, leaf injury, kernel damage, stalk tunneling (southwestern corn borer), and dead or injured plants (lesser cornstalk borer) were greater in the blended non-Bt refuge plants compared to Cry1F×Cry1Ab plants in the non-Bt and pyramided Cry1F×Cry1Ab blended refuge treatment. When non-Bt blended refuge plants were compared to a structured refuge of non-Bt plants, no significant difference was detected in leaf injury, kernel damage, or stalk tunneling (southwestern corn borer). Plant stands in the non-Bt and pyramided Cry1F×Cry1Ab blended refuge treatment had more stalk tunneling from sugarcane borer and plant death from lesser cornstalk borer compared to a pyramided Cry1F×Cry1Ab structured refuge treatment. Hybrid plants containing Cry1F×Cry1Ab within the pyramided Cry1F×Cry1Ab blended refuge treatment had significantly less kernel damage than non-Bt structured refuge treatments. Both single and pyramided Bt traits were effective against southwestern corn borer, sugarcane borer, and lesser cornstalk borer.


Subject(s)
Agriculture/methods , Bacterial Proteins , Endotoxins , Hemolysin Proteins , Herbivory , Lepidoptera , Animals , Bacillus thuringiensis Toxins , Spodoptera
3.
Rev Sci Tech ; 31(3): 943-51, 2012 Dec.
Article in French | MEDLINE | ID: mdl-23520747

ABSTRACT

A study of the prevalence of bovine tuberculosis and brucellosis was conducted in dairy cattle farms in and around the city of Ouagadougou, Burkina Faso. It reveals the potential economic and health impact of these two major zoonoses in the study area. Three farming systems were included in the study. A total of 1,420 cattle were tested for tuberculosis and 1,689 cattle were tested for brucellosis. The intradermal tuberculin test was used for tuberculosis, and the buffered antigen test and indirect enzyme-linked immunosorbent assay were used for brucellosis. The overall prevalence rate is estimated to be 6.05% for tuberculosis and 3.61% for brucellosis. The prevalence rates of tuberculosis and brucellosis in urban and peri-urban dairy cattle farms in Ouagadougou were found to be high. As these two production-linked diseases are zoonotic, they could pose a major risk to human health and contribute significantly to reducing animal production and productivity in the areas covered by the study. Animals should be checked systematically prior to introducing them into dairy herds, with the ultimate goal of eradicating these two zoonoses.


Subject(s)
Brucellosis, Bovine/epidemiology , Tuberculosis, Bovine/epidemiology , Age Factors , Agglutination Tests/veterinary , Animals , Burkina Faso/epidemiology , Cattle , Dairying , Enzyme-Linked Immunosorbent Assay/veterinary , Female , Humans , Male , Prevalence , Sex Factors , Suburban Health , Tuberculin Test/veterinary , Urban Health , Zoonoses/epidemiology
4.
J Econ Entomol ; 98(2): 395-401, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15889730

ABSTRACT

The European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), is one of the most important pests of corn, Zea mays L., because it consistently causes high loss of yield. A study was conducted in 2000-2002 at field sites in central and western Kentucky to investigate whether infestation by O. nubilalis differentially affects the production of high-oil corn compared with traditional field corn. Statistical differences in grain weight and percentage of oil content between the five infestation levels were significant at both locations and for all years. Average grain yield was reduced by 0.40% and average oil concentration by 0.011% for each 1% of damaged plants, and there was a strong correlation (0.76) between leaf damage ratings (i.e., Guthrie scale) and yield reduction. In general, corn planted at the early planting date tended to have a higher yield (grain weight) and oil content.


Subject(s)
Corn Oil/analysis , Lepidoptera/growth & development , Plant Diseases , Zea mays/growth & development , Animals , Edible Grain/anatomy & histology , Zea mays/chemistry
5.
Rev Sci Tech ; 23(1): 147-56; discussion 391-401, 2004 Apr.
Article in French | MEDLINE | ID: mdl-15200093

ABSTRACT

Para-professional agents known as auxiliaries, or community animal health workers, provide low-cost basic veterinary services to communities of livestock producers. A 2003 survey of 16 Sub-Saharan African countries, carried out as part of the Pan-African Programme for the Control of Epizootics, showed that in the majority of cases, the official Veterinary Services have no (or very few) links with the auxiliaries, although they are well aware of their existence and in some cases the auxiliaries have been trained by officials of the Veterinary Services. However, there are isolated cases of countries establishing more formal links, for example, recognising the status of an auxiliary, recognising auxiliaries with no definition of a status, attaching auxiliaries to Veterinary Service staff, establishing agreements for the provision of auxiliary services through livestock producer associations, harmonising auxiliary training programmes, issuing professional auxiliary cards, and setting up a consultation framework on the issue of auxiliaries. Unlike private veterinarians, agents of the official services do not generally perceive auxiliaries as competitors, and sometimes collaboration develops at this level. The authors propose several measures to improve links between the official Veterinary Services and auxiliaries, as follows: the fields of competence of auxiliaries should be defined and their curriculum harmonised, the status of auxiliaries should be recognised, a monitoring and assessment mechanism should be established at senior level in the Veterinary Services, training for livestock producers should be improved.


Subject(s)
Animal Technicians , Community-Institutional Relations , Private Sector , Public Sector , Veterinary Medicine/organization & administration , Africa South of the Sahara , Animals , Education, Veterinary , Humans , Veterinarians , Veterinary Medicine/methods
6.
Sante ; 5(3): 189-93, 1995.
Article in French | MEDLINE | ID: mdl-7640902

ABSTRACT

Clinostomum sp. is a trematode, a parasitic worm, of which the larva infest a number of species of wild fish. In intertropical Africa and particularly in artificial lakes in the east of Burkina Faso, the infestation is especially observed in the cichlids fish. Because cichlids constitute 80 to 90% of the fish catches, enzootic infestation could infringe upon the fisheries, and also adversely affect public health. For this epidemiological study conducted during the first three quarters of 1994, we examined a total of 932 cichlids, a mix of all species. Prevalence (Pr) and intensity (I, number of parasites per fish) were the two indicators of the infestation level. 387 fish were carriers of the parasite, comprising 41.5% of the total. Differences were observed between the species of cichlids. Oreochromis niloticus was the most infested (Pr, 56%; I, 17), followed by Sarotherodon galilaeus (Pr, 44%; I,6); and Hemichromis fasciatus (Pr, 20%; I, 5). In 89% of the carriers, the parasite was localized on the internal face of the operculum and in the pericardial septum, compared to 11% of the localizations in subcutaneous and muscular tissues. These last two localizations render the fish repugnant, and can cause the fresh fish to be rejected. If the parasitized fish is not rejected and then insufficiently cooked, as occurs at public grills with multitudes of consumers, the living parasite can penetrate and stay in the upper digestive tract and constitute a threat for consumer health.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Fish Diseases/epidemiology , Fish Diseases/parasitology , Fisheries , Perches/parasitology , Public Health , Trematode Infections/epidemiology , Animals , Burkina Faso/epidemiology , Disease Vectors , Food Handling , Food Parasitology , Health Education , Humans , Larva , Prevalence , Trematoda/growth & development , Trematoda/isolation & purification , Trematode Infections/transmission , Zoonoses
8.
Am J Vet Res ; 53(10): 1732-3, 1992 Oct.
Article in English | MEDLINE | ID: mdl-1280925

ABSTRACT

Three available differential stains, Camco-Quik, Diff-Quik, and Wright-Giesma were compared for detection of intraerythrocytic Anaplasma marginale in bovine blood smears. In samples where < 1% to more than 51% of the RBC were infected, statistical analysis of the data indicated no significant difference in the detection of A marginale with Camco-Quik or Diff-Quik stains. However, a significantly lower percentage of infected RBC were detected when blood smears were stained with the Wright-Giemsa stain, compared with the other 2 methods.


Subject(s)
Anaplasma/isolation & purification , Cattle/microbiology , Erythrocytes/microbiology , Staining and Labeling/veterinary , Animals , Staining and Labeling/methods
9.
Equine Vet J ; 24(3): 187-90, 1992 May.
Article in English | MEDLINE | ID: mdl-1606931

ABSTRACT

Ten hyperinsulinaemic ponies divided into conditioned (N = 5) and rested (N = 5) groups were evaluated for their insulin and glucose response following oral glucose administration at Weeks 0, 2, 4, and 6. All ponies received a controlled intake of a pelleted ration during the study. In both groups body weight had decreased from baseline by Week 4 and remained low. After 2 weeks of exercise, ponies in the conditioned group had significantly decreased insulin and glucose indices, including peak insulin response, area under the insulin curve from 0 to 210 min (TIS), and the TIS value: area under the glucose curve from 0 to 210 min. By Week 4 of conditioning, although the insulin and glucose indices continued to decrease in the exercised ponies, there was no significant difference between the groups. Over the first 6 weeks of the study all ponies improved their insulin sensitivity accompanied by a loss of body weight. The conditioned ponies were further evaluated during deconditioning at Weeks 8, 10 and 12. The improved insulin sensitivity was maintained during deconditioning.


Subject(s)
Eating , Horse Diseases/therapy , Hyperinsulinism/veterinary , Insulin/metabolism , Physical Conditioning, Animal , Animals , Blood Glucose/analysis , Body Weight , Female , Glucose Tolerance Test/veterinary , Horses , Hyperinsulinism/therapy , Insulin/blood , Insulin Secretion , Male , Nutritional Status
10.
Equine Vet J Suppl ; (11): 13-7, 1992 Feb.
Article in English | MEDLINE | ID: mdl-9109953

ABSTRACT

Twenty-three well-conditioned ponies were evaluated for insulin and glucose response following oral glucose administration (1 g/kg bodyweight [bwt] as a 20 per cent solution). Ponies were defined as normal if total insulin secretion (TIS) was less than 149 mu iu/ml h and the glucose concentration was below 11.1 +/- 0.11 mmol/litre (200 +/- 2 mg/dl) at all times following oral glucose administration. When glucose concentrations were maintained below 11.1 +/- 0.11 mmol/litre, the area under the glucose curve (TG) was less than 17.4 mmol/litre/h (314 mg/dl/h). The ponies were assigned to four groups based on insulin and glucose response: Group 1 (n = 7), normal; Group 2 (n = 5), high insulin, normal glucose; Group 3 (n = 8), high insulin, high glucose and Group 4 (n = 3), high glucose, normal insulin. This classification is an initial attempt to define normal insulin and glucose response in ponies. Additional data need to be accumulated to define further insulin resistance and diabetes in ponies.


Subject(s)
Blood Glucose/analysis , Glucose/pharmacology , Horses/metabolism , Insulin/metabolism , Physical Conditioning, Animal/physiology , Administration, Oral , Analysis of Variance , Animals , Blood Specimen Collection/veterinary , Dexamethasone/administration & dosage , Glucose/administration & dosage , Glucose Tolerance Test/veterinary , Hydrocortisone/blood , Injections, Intramuscular/veterinary , Insulin Secretion
11.
J Vet Intern Med ; 5(1): 15-22, 1991.
Article in English | MEDLINE | ID: mdl-2020012

ABSTRACT

Ponies were evaluated for their response to feed withholding and exogenous administration of corticosteroids (dexamethasone 0.04 mg/kg intramuscular [IM]) in an attempt to reproduce the hyperlipemia syndrome. Because insulin resistance has been associated with hyperlipemia, all ponies were initially evaluated for insulin response to an oral glucose load and normal dexamethasone suppression of serum cortisol. Four ponies were identified as hyperinsulinemic reflecting insulin resistance. All ponies had suppressed cortisol concentrations following dexamethasone administration. Feed withdrawal resulted in hypertriglyceridemia by 48 hours in all ponies. Very low density lipoprotein-triglyceride (VLDL) fraction was primarily elevated. The administration of dexamethasone failed to increase the degree of triglyceridemia. Although insulin resistance has been proposed as the likely cause of the hypertriglyceridemia in ponies, in this study four of eight ponies were considered to have normal insulin responses and yet still developed hypertriglyceridemia.


Subject(s)
Fasting/blood , Horses/blood , Hydrocortisone/blood , Insulin/blood , Triglycerides/blood , Animals , Blood Glucose/analysis , Dexamethasone , Female , Glucose Tolerance Test/veterinary , Male
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