Impact of a mixed chain length omega-3 fatty acid diet on production variables in commercial free-range laying hens

1. Previous studies found beneficial effects on the prevalence of keel fractures and bone health in laying hens receiving a short chain ω3 fatty acid diet. However, subsequent work using a mixed short and long chain ω3 diet (MCD) found little benefit to bone health and substantial production losses.

2. The current study examined commercial use of a mixed chain length ration in multiple farms and flocks and identified a detrimental effect on productivity including: mortality, number of poor quality eggs, hen daily average, feed consumption, and increased egg weight.

3. Production data were acquired from 11 flocks housed on 5 farms and modelled using MlwiN, a statistical package developed for analysis of hierarchical data. Production responses were individually modelled with duration of exposure to the diet, age of introduction, flock size and farm, included as prediction variables.

4. Analysis indicated birds receiving the MCD manifested dramatic increases in mortality, poor quality eggs, mean egg weight, feed consumption and decreased production in comparison to control flocks receiving a standard ration. Increased exposure time appeared to increase the magnitude of the diet effect.

5. Although no data were collected to explain the potential mechanisms of this diet, the authors discuss several possible scenarios including excessive long chain ω3 content overwhelming eicosanoid regulatory capacity and changes in behaviour patterns.     

Determination of altosid insect growth regulator in waters, soils, plants, and animals by gas-liquid chromatography.

Residues of isopropyl (2E,4E)-11-methoxy-3,7,11-trimethyl-2,4-dodecadienoate (Altosid) insect growth regulator are determined in waters, soils, plants, milk, eggs, fish, shellfish, poultry and cattle tissues, blood, urine, and feces. Acetonitrile is the primary extraction solvent for all samples. Residues are extracted by high-speed blending followed by vacuum filtration. Fatty extracts are subjected to cold-temperature precipitation and filtration. Samples are cleaned up by petroleum ether partitioning and Florisil and neutral alumina chromatography. The concentrated eluants are analyzed by gas-liquid chromatography (GLC) on columns of differing polarity, using hydrogen flame ionization detectors. The identity of suspected residues is confirmed by additional GLC and by mass fragmentography. The lower limits of detection were: water samples, 0.0004-0.001 ppm; soils, blood, and urine, 0.001 ppm; forage grasses, forage legumes, and rice foliage, 0.005 ppm; and milk, eggs, fish, shellfish, poultry and cattle tissues, and feces, 0.010 ppm.     

Fluid inclusion assemblages of the stratiform broken hill ore deposit, new South wales, australia

Minerals of the Broken Hill lode in New South Wales, Australia, have a rich assemblage of fluid inclusions. Most typically they contain a high-salinity aqueous liquid and a high-density carbon dioxide and methane gas. Northerly trending shear zones in the area are characterized by a distinct assemblage of inclusions. The inclusions provide a record of the sequence of metamorphic fluids since the period of high-grade metamorphism. Inclusions from the period of ore formation have been eliminated by repeated deformation and recrystallization.     

Buying into the food system: Trends in food retailing in the US and implications for local foods

The contemporary US food systemis characterized by both an unprecedentedconcentration of corporate control as well as afragmentation of sourcing and marketingprocesses, introducing both new constraints andnew opportunities for more localized foodsystems. The purpose of our study is to explorethese issues by investigating three keyquestions. First, what are the key trends inthe US grocery industry? Second, how dodifferent kinds of food outlets choose,procure, and promote food products? Finally,what are the implications of recent trends inthe food retailing process for strengtheninglocal flows of the production, distribution,and consumption of food? Background informationon the grocery industry and the results ofseven open-ended interviews conducted withowners and managers of grocery stores in oneupstate New York county indicate that theretailing process differs in complex ways fromstore to store and in most aspects cannot beinferred from store type. The paper concludeswith a discussion of the implications of ourfindings for local food system efforts,specifically in terms of new collaborationsamong producers, distributors, retailers, andshoppers, who play an indispensable role indeveloping viable alternatives to increasingcorporate control.     

THE ENSILAGE OF AUTUMN-SOWN RYE

Autumn-sown rye was cut on five dates in spring and ensiled in laboratory silos. On two of the dates forage-harvested material was ensiled in PVC silos (containing about 1 t of fresh crop) as well as in laboratory silos. Ensiling was carried out with and without the addition of formic acid or glucose solution. After 96 days in laboratory silos, rye cut before ear-emergence and ensiled without additives gave silages of high pH value and high ammonia content. After ear-emergence satisfactory silage was produced without an additive, but the addition of formic acid always resulted in silages having lower pH values and lower ammonia contents. The addition of glucose resulted in silages with only slightly lower pH values and ammonia contents which were closely similar to those made without addition. Silages made in PVC silos were all well preserved, as indicated by low contents of acetic and butyric acids, but the addition of formic acid resulted in pH values and ammonia contents lower than those found in other treatments.     

Comparison of bacterial culture, polymerase chain reaction, and a mix-enzyme-linked immunosorbent assay for the detection of Salmonella status in grow-to-finish pigs in western Canada with a Bayesian approach

Among grow-to-finish pigs from 10 herds in Alberta and Saskatchewan, 23 (16%) of 144 fecal samples were culture-positive and 40 (28%) of 144 pigs were seropositive for Salmonella. With a Bayesian model specifying dependence between the 2 tests, the sensitivity (Se) of culture and real-time polymerase chain reaction (RT-PCR) was 79% to 86%, depending on the cut-off value for the enzyme-linked immunosorbent assay (ELISA). Culture specificity (Sp) was assumed to be 100%; RT-PCR Sp was found to be 94%. The ELISA Se was 76% and 51% at optical density cut-off values ≥ 20% and ≥ 40%, respectively; the Sp was 94% at each cut-off value. The model showed some sensitivity to ELISA prior information, the ELISA Se being approximately 8% lower when informative prior information was specified in the model. When there was no adjustment for dependence between culture and RT-PCR, the posterior estimates for both culture and RT-PCR Se were 11% higher than with the conditional-dependence model and had considerably narrower probability intervals, which suggests that correlation between culture and PCR is important and should be adjusted for in future studies.