Short-chain fatty acids affect cell-association and invasion of HEp-2 cells by Salmonella typhimurium.

This study demonstrates that the growth of S. typhimurium in Luria Bertani broth supplemented with acetate, propionate, butyrate, or a mixture of the three SCFA, affected cell-association and the ability to invade cultured HEp-2 cells. Cell-association and invasion was determined after growth for 4 h of growth in the presence of the SCFA at pH 6 and 7.

A halothane test to detect turkeys prone to developing pale, soft, and exudative meat.

The turkey industry suffers from pale, soft, and exudative meat (PSE) that is unsuitable for further processing because of excessive color variation, poor meat binding, and depressed water holding ability. This condition is caused by accelerated postmortem muscle metabolism and is thought to be related to a similarly inherited condition in swine. A quick, nondestructive method of screening animals is needed to avoid further propagation of PSE in breeding flocks.

Meat quality and rigor mortis development in broiler chickens with gas-induced anoxia and postmortem electrical stimulation.

This study was conducted to evaluate the combined rigor-accelerating effects of postmortem electrical stimulation (ES) and argon-induced anoxia (Ar) of broiler chickens. One hundred broilers were processed in the following treatments: untreated controls, ES, Ar, or Ar with ES (Ar + ES). Breast fillets were harvested at 1 h postmortem for all treatments or at 1 and 6 h postmortem for the control carcasses.

Evaluation of sorghum ergot toxicity in broilers.

Three experiments evaluated the performance of broilers fed sorghum ergot consisting of sphacelia/sclerotia of Claviceps africana present in tailings removed by conditioning of seed from grain sorghum hybrid seed production fields near Uvalde (Experiments 1 and 2) and Dumas (Experiment 3), Texas. Percentage sphacelia/sclerotia and total alkaloid content, respectively, in sorghum ergot tailings were 8% and 11.3 ppm for Uvalde and 75% and 235 ppm for Dumas.

A comparison of texture and quality of breast fillets from broilers stunned by electricity and carbon dioxide on a shackle line or killed with carbon dioxide.

To compare the broiler breast muscle quality resulting from three different slaughter methods, 36 broilers in each of two replicates were randomly divided into three groups receiving CO2 stunning, electrical stunning (ES), or CO2 killing. Carbon dioxide stunning was accomplished in a tunnel with a gradient from 40 to 60% CO2 by allowing the broilers on shackles to pass through the tunnel for 25 s. Electrical stunning was done by passing the bird's head through a charged 1% brine solution (35 mA, 7 s).

Consumer poultry meat handling and safety education in three Texas cities.

Shifting demographics, increased poultry consumption and a general ignorance concerning food safety measures provide the potential for increased foodborne illness. In order to determine where food safety educational efforts would be most effective and the needed content of the messages, a survey addressing poultry preparation, storage and thawing methods, and sources of food safety education was constructed and distributed in supermarkets in three Texas urban centers. Between 60 and 67% of consumers prepared poultry once or twice per week.

Antibiotic amendment for suppression of indigenous microflora in feed sources for an Escherichia coli auxotroph lysine assay.

Growth responses of lysine auxotrophic mutants of Escherichia coli have been used as a measurement of bioavailable lysine in protein sources and animal feeds. Sterilizing feed samples by autoclaving to eliminate non-specific background growth of indigenous feed micro-organisms prior to conducting the bacterial assay may introduce chemical and physical alterations to the feeds, influencing the estimation of available feed lysine. In this study, an antibiotic- and antifungal-supplemented medium was constructed to support growth of an E.

Conventional and molecular methods for understanding probiotic bacteria functionality in gastrointestinal tracts.

The recent successes of probiotic application to limit colonization of foodborne pathogens in the gastrointestinal tracts of food animals ensures continued commercialization and widespread use of such cultures. Given that the the fermentation response and ecological balance of the probiotic consortium appears to be essential for the effectiveness of the cultures, it is essential to develop a methodology to accurately identify and quantitate these organisms during commercial production as well as successful in vivo colonization after administration. However, if further optimization of the effectiveness of defined cultures is to be achieved, methods to assess expression of key metabolic processes occurring during establishment of the probiotic culture as well as its subsequent ability to limit foodborne pathogen colonization are needed.

Meat quality during processing.

The study of growth and development of any food animal such as poultry needs to consider the effects of the muscle changes on the use of the muscle as meat. If a treatment could increase muscle growth but the increased meat was of poor quality, then the increase in production would be of little value. Muscle is of particular concern because not only is it the tissue of greatest value for food, but it also is an excitable tissue and responsive to its environment.

Tenderness of broiler breast fillets from carcasses treated with electrical stimulation and extended chilling times.

Postmortem electrical stimulation (ES) (450 V, 450 mA, 2 s on, 1 s off for five pulses) has been shown to decrease the toughness associated with early deboning. Most studies involving this system have been concerned with obtaining "acceptable" tenderness in fillets deboned at about 1 h postmortem, the time of carcass exit from an immersion chiller. However, the effects of ES combined with deboning at 2 h postmortem needs to be evaluated because some processors are considering extended immersion chilling and those already using air chilling require approximately 2 h for this process.

Effect of bursal antisteroidogenic peptide (BASP) on chicken embryonic pituitary secretion of growth hormone (GH) and prolactin (PRL): evaluation in a reverse hemolytic plaque assay (RHPA).

Using the reverse hemolytic plaque assay described in the present investigation, a secretagogue activity of bursal antisteroidogenic peptide (BASP) for growth hormone (GH) or prolactin (PRL) secretion was observed in chicken Day 20e pituitary cell monolayers. Partially purified BASP (ppBASP), at all concentrations evaluated (0.25 BEQ/ml, 0.

Commercial implementation of postmortem electrical stimulation.

Postmortem electrical stimulation (ES) of meat-producing species is not a new technology but has recently been adapted for commercial use with poultry. Unlike its use in red meats to reduce the inherent toughness and facilitate grading, the application of ES in poultry is to reduce the need for aging carcasses before deboning by reducing the toughening that occurs when the meat is deboned early after death. The current practice of aging intact carcasses or breast halves 4 h or more prior to deboning costs the industry millions of dollars in lost yield and creates logistical problems in plants.

Postmortem pH, myofibrillar fragmentation, and calpain activity in Pectoralis from electrically stimulated and muscle tensioned broiler carcasses.

Broiler carcasses were conventionally processed or were electrically stimulated (ES) and had their Pectoralis muscles tensioned during rigor mortis development (ES/MT) to evaluate the relationship between the course of postmortem muscle pH decline and myofibrillar fragmentation. Samples from Pectoralis fillets harvested at 0, 0.5, 1, 2, and 24 h postmortem were analyzed for pH, myofibrillar fragmentation index, and calpain activity.

Bleedout efficiency, carcass damage, and rigor mortis development following electrical stunning or carbon dioxide stunning on a shackle line.

In Experiment 1, 400 male broilers were stunned using a gradient of 40 to 60% CO2 over a period of 25 s or a 1% brine solution that was electrically charged (35 mA) for 7 s. Blood loss during bleeding was measured in 30-s intervals for a total of 120 s. After conventional processing and chilling, carcass damage was subjectively evaluated.

The impact of pH on nitrogen retention in laboratory analysis of broiler litter.

Land application of broiler litter must fully regard agronomic and environmental issues, which requires increased precision in all aspects of land application of poultry litter. Previous researchers note that litter experiences significant nitrogen loss due to ammonia volatilization during the drying process. Others note that pH of poultry houses and litter significantly affects nitrogen loss due to ammonia volatilization.

Meat quality of broiler breast meat following post-mortem electrical stimulation at the neck.

This experiment was conducted to evaluate the effects of electrical stimulation (ES) on breast fillets harvested at 1 h post-mortem and individually quick frozen (IQF) or aged on ice (ICE). Twelve birds were electrically stimulated (450 V, 750 mA, 2 s on/1 s off for 15 s) at the neck in a saline bath. Twenty-four unstimulated birds were used as controls.

Dietary methionine intake effects on egg component yield, composition, functionality, and texture profile analysis.

The influence of supplemental Met levels ranging from 413 to 556 mg per hen per d (mg/HD) on liquid egg component yield, composition, and functionality was examined in mature layers (29 wk of age). Egg weight, component yield, solids, and CP content of albumen and yolk were determined. Texture profile analysis, feed ingredient functionality testing, and PAGE were conducted to determine whether increased egg total solids and CP content resulted in altered egg component functionality or electrophoretic protein banding pattern.

Dietary marine algae maintains egg consumer acceptability while enhancing yolk color.

A drum-dried docosahexaenoic acid (DHA; C22:6n-3) enriched marine microalgal product (MA) was investigated as a n-3 fatty acid (n-3 FA) source in laying hen diets. Hen diets were supplemented with 2.4 or 4.

Detection and quantification of poultry probiotic bacteria in mixed culture using monoclonal antibodies in an enzyme-linked immunosorbent assay.

Murine monoclonal antibodies were used in an enzyme-linked immunosorbent assay (ELISA) for the detection and quantification of selected probiotic bacteria present in a continuous-flow competitive exclusion culture known to be effective at reducing chicken cecal and crop colonization by Salmonella typhimurium. Veillonella, Enterococcus avium and S. typhimurium were grown anaerobically in batch culture of Viande Levure broth in pure culture and mixed culture.

Pale, soft, and exudative meat in turkeys treated with succinylcholine.

Rapid post-mortem metabolism concomitant with the early onset of rigor mortis can lead to the development of pale, soft, and exudative (PSE) meat. However, a reliable, nonlethal method for induction of this syndrome for the ante-mortem identification of abnormal turkeys has not been identified. The present study was conducted to evaluate the potential use of succinylcholine for inducing PSE meat in susceptible turkeys.

Rigor mortis development at elevated temperatures induces pale exudative turkey meat characteristics.

Development of rigor mortis at elevated post-mortem temperatures may contribute to turkey meat characteristics that are similar to those found in pale, soft, exudative pork. To evaluate this effect, 36 Nicholas tom turkeys were processed at 19 wk of age and placed in water at 40, 20, and 0 C immediately after evisceration. Pectoralis muscle samples were taken at 15 min, 30 min, 1 h, 2 h, and 4 h post-mortem and analyzed for R-value (an indirect measure of adenosine triphosphate), glycogen, pH, color, and sarcomere length.

Expression of chicken thyroid-stimulating hormone beta-subunit messenger ribonucleic acid during embryonic and neonatal development.

The importance of thyroid hormone from embryonic through neonatal life has been documented in both avian and mammalian species. However, the regulation of thyroid hormone production during this period is not completely understood. The objective of this study was to characterize expression of chicken TSHbeta messenger RNA (mRNA) compared with that of thyroid hormones and GH in embryonic and neonatal chickens.

The effect of seasonal heat stress on rigor development and the incidence of pale, exudative turkey meat.

Heat stress is one of the prominent ante-mortem stressors that elicits pale, soft, and exudative meat characteristics in stress-susceptible pigs. Industry reports of exudative turkey meat increase in the early summer with the onset of prolonged high temperatures. To study the effect of seasonal heat exposure on turkeys, 122 17-wk-old Nicholas tom turkeys were subjected in January either to growth temperatures of 16/24 C (night/day) (control) or to elevated temperatures of 32/38 C (night/day) (heat-stressed, HS).

Identification of the blood-borne somatotroph-differentiating factor during chicken embryonic development.

Somatotrophs become a significant population by day 16 of chicken embryonic development. We have previously demonstrated that an earlier induction of GH cell differentiation is possible with the addition of day 16 embryonic serum to cultures of day 12 pituitary cells, an age when somatotrophs are rare. The present study was designed to identify the blood-borne signal(s) responsible for the serum activity, using reverse hemolytic plaque assays to identify individual GH-secreting cells.

Differential responsiveness of somatotrophs to growth hormone-releasing hormone and thyrotropin-releasing hormone during chicken embryonic development.

This study was designed to evaluate responsiveness and sensitivity of pituitaries from chickens to growth hormone (GH) secretagogues during late embryonic development. Anterior pituitary cells from 16-, 18- and 20-day-old chicken embryos were subjected to reverse hemolytic plaque assays (RHPAs) for GH in the presence of GH-releasing hormone (GHRH) and thyrotropin-releasing hormone (TRH). The proportion of somatotrophs detected increased between embryonic days 16 and 20, from 16 to 19.