Imprecision when using measuring cups to weigh out extruded dry kibbled food

Many pet cats and dogs are fed dry extruded kibbled food by measuring cup, yet the precision and accuracy of this feeding strategy is not known. Over 12 studies, we assessed precision and accuracy of weighing out food portions, of various dry kibbled foods, by measuring cup. Poor precision was noted in all studies, with intra- and inter-subject coefficients of variation ranging from 2 to 13% and 2 to 28% respectively. Variable accuracy was also noted, which ranged from an 18% under-estimate to an 80% over-estimate in portion size. No specific factors were associated with imprecision, but the degree of inaccuracy was negatively associated with portion size (R = -0.67, p = 0.022), and positively associated with the number of subjects participating in the study (R = 0.60, p = 0.048). This is the first study to document imprecision and inaccuracy of using measuring cups to estimate portions of extruded dry kibbled food. Over time, such errors could contribute to insidious weight gain in companion animals, potentially contributing to the development of obesity. Imprecision in measuring food portions could also contribute to failure of weight management programmes for obese animals.     

Optimization of hydrolytic and oxidative enzyme methods for ecosystem studies

Microbial digestive enzymes in soil and litter have been studied for over a half century, yet the understanding of microbial enzymes as drivers of ecosystem processes remains hindered by methodological differences among researchers and laboratories. Modern techniques enable the comparison of enzyme activities from different sites and experiments, but most researchers do not optimize enzyme assay methods for their study sites, and thus may not properly assay potential enzyme activity. In this review, we characterize important procedural details of enzyme assays, and define the steps necessary to properly assay potential enzyme activities in environmental samples. We make the following recommendations to investigators measuring soil enzyme activities: 1) run enzyme assays at the environmental pH and temperature; 2) run proper standards, and if using fluorescent substrates with NaOH addition, use a standard time of 1 min between the addition of NaOH and reading in a fluorometer; 3) run enzyme assays under saturating substrate concentrations to ensure V_max is being measured; 4) confirm that product is produced linearly over the duration of the assay; 5) examine whether mixing during the reaction is necessary to properly measure enzyme activity; 6) find the balance between dilution of soil homogenate and assay variation; and 7) ensure that enzyme activity values are properly calculated. These steps should help develop a unified understanding of enzyme activities in ecosystem ecology.     

Morphology of the Atlantic salmon (Salmo salar) tongue

The Atlantic salmon (Salmo salar) is a freshwater and marine fish of the family Salmonidae, widely farmed in aquaculture facilities in several countries. The salmon are carnivorous, but in aquaculture, alternative foods have been experienced. It is well known that feeding in captivity should cause adaptation and modifications of the morphological characteristics of the oral cavity, especially of tongue; therefore, the aim of this study was to investigate, by light, laser confocal and scanning electron microscopy, the morphological characteristics of the tongue dorsal surface, considering the importance of the correlations between feeding habits and the anatomy of the tongue. Scanning electron microscopy demonstrates the presence of caniniform teeth with oro-aboral orientation surrounded by numerous filiform papillae, single, fused or arranged in row. Oro-aborally, the papillae show an appearance like a rosette and they disappear at level of the root. Light and laser confocal microscopy demonstrates that the mucosa is covered by a non-keratinized stratified pavement epithelium with, in the deepest layer, the presence of a triangular structure whose apex is cranially directed and base facing aborally. In this structure, spindle-shaped cells are present, with a vimentin immunoreactivity, that for their characteristics could be adult mesenchymal stem cells. The obtained data could be useful not only for further studies on the nutrition, but it is interesting the detection of tissues typical of the embryo-fetal phase in the adult specimens tongue, thus giving a basis for studies of potential applications, if any, regarding cell therapies for different clinical indications.     

Chemical composition and antimicrobial activity of Momordica charantia seed essential oil

The essential oil obtained from the seeds of Momordica charantia was analyzed by GC/MS. Twenty-five components, representing 90.9% of the oil, were identified. The main constituents were trans-nerolidol, apiole, cis-dihydrocarveol and germacrene D. Furthermore, the oil was tested for its antibacterial and antifungal activities. Staphylococcus aureus was found to be the most sensitive microorganism with MIC values <500 microg/ml.     

Long‐term Effects of Pyrethrin and Cyfluthrin,a Type II Synthetic Pyrethroid,Insecticide Applications on Bull Reproductive Parameters

The objectives of this study were to determine effects of cyfluthrin and pyrethrin spray products, used in combination with cyfluthrin topical and ear tag applications, on bull reproductive parameters over 18 weeks. Angus or Angus x Simmental bulls were randomly assigned to one of three treatment groups: (i) no exposure to pyrethrins/cyfluthrin (CONT; n = 10), (ii) cyfluthrin ear tag and topical applications (ET; n = 10), or (iii) cyfluthrin ear tag, topical, premise spray and pyrethrin fog spray applications (ET+S; n = 8). Bull body weight was measured every 3 week, and body condition score and scrotal circumference were recorded on weeks 0, 9 and 18. Semen and serum were collected every 3 weeks for sperm evaluation and testosterone measurement, respectively. There was a treatment × week interaction (p < 0.01) for sperm with primary defects; bulls in CONT group had a greater (p = 0.01) percentage of sperm with primary defects than bulls treated with insecticides at week 18. Overall and progressive sperm motility, normal sperm morphology, secondary sperm defects and serum testosterone concentrations changed (p < 0.01) over time in all bulls; however, treatment did not affect (p ≥ 0.13) any of these parameters. There were also no treatment effects (p ≥ 0.08) on bull body weight, body condition score or scrotal circumference. The use of pyrethrin‐ and cyfluthrin‐based insecticides, regardless of application, did not negatively affect reproductive parameters in beef bulls when administered over 18 weeks.     

Presence and distribution of leptin and its receptor in the gut of adult zebrafish in response to feeding and fasting

Leptin is an anorectic hormone secreted mainly by peripheral adipocytes but also by other central and peripheral tissues. It acts by means of a receptor called OB‐R, influencing not only appetite and body mass but being also involved in many fields like endocrinology, metabolism and reproduction. Immunohistochemistry and qRT‐PCR techniques were, respectively, used to demonstrate the presence of leptin and its receptor in the gut of adult zebrafish and to evaluate the leptin gene expression response to feeding and fasting. Immunoreactivity for the antibodies utilized was demonstrated in feeding but not in fasting fish, and the gene expression analysis corroborates the data obtained by immunohistochemistry. Therefore, all the obtained results support the hypothesis of the role of this hormone in food regulation in zebrafish.     

Assessing extractable soil phosphorus methods in estimating phosphorus concentrations in surface run‐off from Calcic Hapludolls

Understanding soil test phosphorus (STP) and surface run‐off phosphorus (P) relationships for soils is necessary for P management. The objective of the study was to evaluate the efficacy of various soil test indices to predict P losses in surface run‐off. Selected sites were subjected to in situ rainfall simulations according to the protocol of the National Phosphorus Research Project ( NPRP, 2001 ). P from a composite of twenty‐four 2.0‐cm‐diameter core soil samples (0–5 cm) was extracted using the Olsen, Bray–Kurtz, Mehlich III, distilled water and 0.01 m calcium chloride procedures. All of these P extraction methods explained a significant amount of variability in surface run‐off total dissolved P [TP (<0.45)] (r² ≥ 0.67; P ≤ 0.01), where 0.45 is the filter pore diameter in microns. Multiple regression models showed extractable P to be the best soil predictor of surface run‐off TP (<0.45) among the studied soils. Despite extraction method or soil type, extractable P was the best soil predictor of surface run‐off TP (<0.45). Either agronomic (0.92 ≤ r² ≤ 0.96) or environmental (0.94 ≤ r² ≤ 0.96) soil tests were effective in estimating surface run‐off TP (<0.45) in select Mollisols.