United States Department of Agriculture-Agricultural Research Service research on natural products for pest management

Recent research of the Agricultural Research Service of USDA on the use of natural products to manage pests is summarized. Studies of the use of both phytochemicals and diatomaceous earth to manage insect pests are discussed. Chemically characterized compounds, such as a saponin from pepper (Capsicum frutescens L), benzaldehyde, chitosan and 2-deoxy-D-glucose are being studied as natural fungicides. Resin glycosides for pathogen resistance in sweet potato and residues of semi-tropical leguminous plants for nematode control are also under investigation. Bioassay-guided isolation of compounds with potential use as herbicides or herbicide leads is underway at several locations. New natural phytotoxin molecular target sites (asparagine synthetase and fructose-1,6-bisphosphate aldolase) have been discovered. Weed control in sweet potato and rice by allelopathy is under investigation. Molecular approaches to enhance allelopathy in sorghum are also being undertaken. The genes for polyketide synthases involved in production of pesticidal polyketide compounds in fungi are found to provide clues for pesticide discovery. Gene expression profiles in response to fungicides and herbicides are being generated as tools to understand more fully the mode of action and to rapidly determine the molecular target site of new, natural fungicides and herbicides.     

Effect of transport loading or noise on blood biochemical variables in calves

The influence of 2 transport stressors (loading and noise) on several serum and plasma biochemical variables was studied in 4 calves. When calves were loaded and kept for 30 minutes on a motionless transport simulator or were exposed to the noise of the working simulator, increases in plasma epinephrine and serum cortisol and nonesterified fatty acids concentrations were similar to changes observed in calves subjected to simulated transport for 30 minutes. Results indicate that loading and noise have an important role in transport stress.     

The effect of nerve growth factor on nuclear progression of porcine oocytes during in vitro maturation and embryo development

The present study examined the effect of nerve growth factor (NGF) on in vitro maturation (IVM), in vitro fertilisation (IVF) and subsequent embryonic development of porcine oocytes. Cumulus-oocyte complexes were cultured with or without 1.0 ng/ml NGF for 40 h. After IVF, they were cultured in vitro for 6 days. After 10 and 20 h of IVM, there was no difference in nuclear status between the NGF-treated and control oocytes. Significant differences were detected in nuclear progression of oocytes matured in the presence or absence of NGF at 30 h of culture. A higher proportion of NGF-treated oocytes were at M-II stage compared to the control. Nevertheless, at the end of the 40-h IVM period, there was no difference in the proportion of M-II stage oocytes between the NGF-treated and control groups. NGF in IVM medium did not influence the developmental competence of putative embryos. Most embryos remained at the 2- to 4-cell stage; however, a significant amount of embryos reached the morula stage both in the NGF and the control groups. These results suggest that NGF during IVM accelerates nuclear progression of porcine oocytes by enhancing the post-diakinetic events of meiosis.     

Hatchery hygiene evaluation as measured by microbiological examination of samples of fluff

The microbial content of 1,180 samples of fluff from hatchers at 18 chick and 6 turkey hatcheries has been determined. The samples were taken (a) 12–15 hr before removal of birds from the hatchers, (b) just before or after theremoval of chicks orpoults, (c) after fumigation and (d) inreplicate from the same hatcher.

Fifty‐eight per cent of the samples of chick fluff contained one million or more bacteria but only 24 per cent contained more than 100,000 coli‐aerogenes bacteria. Moulds were not found in 68 per cent of the samples. Some samples of fluff were examined for coagulase positive staphylococci and fluorescent pseudomonads but these organisms were generally not detected. Bacillus cereus was recovered in very large numbers from a few samples. Bacterial and coli‐aerogenes counts from poult fluff were generally higher than those from chick fluff but the numbers of pseudomonads and coagulase positive staphylococci recovered were generally negligible.

In an intensive study of samples of fluff from one turkey hatchery, it was found that the level of contamination of fluff increased during hatching and the laying season and was accompanied by a decrease in poult quality. Sampling from any location in the hatcher appears to provide a representative indication of overall contamination at that time. Fumigation of fluff and debris generally caused a reduction in the level of contamination in the fluff.

A suggested assessment of hatchery hygiene based on the microbial examination of fluff is given and the advantages and disadvantages of this method are discussed.     

Amino acid composition,relative nutritive value and in vitro protein digestibility of several Philippine indigenous legumes

This study demonstrates variability in amino acid composition among accessions of several Philippine indigenous legumes. Moreover, two accessions ofD. lablab were identified to have high level of methionine (>2%). Methionine was identified as the first limiting amino acid with leucine, and threonine as the second limiting amino acids for most legumes studies.The IVPDs of the legumes under study ranged from >70 to 79%. Raw mature seeds had relatively low RNVs of 11 to 68% which increased to 68 to 94% and 51 to 89% after boiling and roasting, respectively.     

Anthocyanin-rich açai (Euterpe oleracea Mart.) fruit pulp fractions attenuate inflammatory stress signaling in mouse brain BV-2 microglial cells

Age-related diseases of the brain compromise memory, learning, and movement and are directly linked with increases in oxidative stress and inflammation. Previous research has shown that supplementation with berries can modulate signaling in primary hippocampal neurons or BV-2 mouse microglial cells. Because of their high polyphenolic content, fruit pulp fractions of a?ai ( Euterpe oleracea Mart.) were explored for their protective effect on BV-2 mouse microglial cells. Freeze-dried a?ai pulp was fractionated using solvents with different polarities and analyzed using HPLC for major anthocyanins and other phenolics. Fractions extracted using methanol (MEOH) and ethanol (ETOH) were particularly rich in anthocyanins such as cyanidin, delphinidin, malvidin, pelargonidin, and peonidin, whereas the fraction extracted using acetone (ACE) was rich in other phenolics such as catechin, ferulic acid, quercetin, resveratrol, and synergic and vanillic acids. Studies were conducted to investigate the mitigating effects of a?ai pulp extracts on lipopolysaccharide (LPS, 100 ng/mL) induced oxidative stress and inflammation; treatment of BV-2 cells with acai fractions resulted in significant (p < 0.05) decreases in nitrite production, accompanied by a reduction in inducible nitric oxide synthase (iNOS) expression. The inhibition pattern was emulated with the ferulic acid content among the fractions. The protection of microglial cells by a?ai pulp extracts, particularly that of MEOH, ETOH, and ACE fractions, was also accompanied by a significant concentration-dependent reduction in cyclooxygenase-2 (COX-2), p38 mitogen-activated protein kinase (p38-MAPK), tumor necrosis factor-α (TNFα), and nuclear factor κB (NF-κB). The current study offers valuable insights into the protective effects of a?ai pulp fractions on brain cells, which could have implications for improved cognitive and motor functions.     

Ecological network analysis: an application to the evaluation of effects of pesticide use in an agricultural environment

Ecological network analysis is used to evaluate the impact of pesticide use on ecological systems in the context of agricultural farmland environments. The aim is to provide support for the design of effective and minimally damaging pest control strategies. The ecological network analysis can identify species that are important to the integrity of the ecological network. The methodology can be used to monitor the impact of shifts in terms of types of pesticide used on the ecological system. The authors' intention is to use this methodology to provide supporting evidence for the UK Voluntary Initiative programme aimed at convincing farmers voluntarily to make improved choices in the use of a wide range of pesticides.