Effect of source of cattle and distance transported to a commercial slaughter facility on carcass bruises in mature beef cows.

OBJECTIVE: To determine the effect of source of cattle and distance cattle were transported to a commercial slaughter facility on prevalence and severity of carcass bruises in mature beef cows. DESIGN: Epidemiologic investigation. SAMPLE POPULATION: Carcasses from 3,955 beef cows from 11 states assembled in 89 procurement lots. PROCEDURE: Each carcass was scored for bruise severity and location. Source of cattle was categorized. Distance from source to slaughter facility was determined. An ANCOVA was used to determine effects of variables on carcass bruises. RESULTS: Mature beef cows marketed through livestock auctions conducting first-point testing for brucellosis, especially when transported longer distances (> 325 km) to slaughter facilities, had a greater number and severity of carcass bruises than cows originating from ranches or livestock auctions not conducting first-point testing. There was an increase in number of rib bruises in cows originating from livestock auctions not conducting first-point testing. Prevalence and severity of bruises were not significantly affected by transportation distance between cows originating from auctions not conducting first-point testing and cows originating from ranches. CLINICAL IMPLICATIONS: A strong association existed between handling for brucellosis testing prior to sale for slaughter and distance transported to slaughter facility with carcass bruises in mature beef cows. Bruises are major quality defects that decrease carcass value and slaughter-cow prices. Repeated handling and restraint as well as long-distance transport are issues to consider regarding the responsibility of the livestock industry to provide for the safety and well-being of cattle sold for slaughter.

Persistent pulmonary hypertension of the neonate and asymmetric growth restriction.

OBJECTIVE: To evaluate the possible associations between persistent pulmonary hypertension of the neonate, need for extra-corporeal membranous oxygenation, small for gestational age (SGA), and low ponderal index for gestational age in infants with persistent pulmonary hypertension of the neonate and in matched controls. METHODS: Eighty-six infants with persistent pulmonary hypertension of the neonate delivered from 1991 to 1994 at our hospital were matched with 430 contemporaneous control singleton neonates. Birth weight and ponderal indices (100 x weight/length3) less than the tenth percentile for gestational age and gender were defined as SGA and low ponderal index, respectively. We assessed associations between these markers, the presence of persistent pulmonary hypertension of the neonate, and the need for extracorporeal membranous oxygenation. RESULTS: Low ponderal index was associated with persistent pulmonary hypertension of the neonate (odds ratio [OR] 5.4), whereas SGA was not. Low ponderal index (OR 4.0) was an independent correlate of persistent pulmonary hypertension of the neonate after adjustment with logistic regression for 5-minute Apgar scores less than 7, umbilical arterial pH less than 7.10, and presence of meconium. Low ponderal index was associated with need for extracorporeal membranous oxygenation in neonates with persistent pulmonary hypertension (P < .001). CONCLUSION: Fetal developmental events may significantly affect neonatal pulmonary status. Diminished neonatal nutritional status, as measured by low ponderal index for gestational age, is associated with increased risk of persistent pulmonary hypertension of the neonate and severity of the disease process.

Estimating the maximum effective dose in a quantitative dose-response experiment.

A simulation study was conducted to compare several procedures for estimating the maximum effective dose in a quantitative dose-response experiment. Using four equally spaced dose levels, data were generated from four different model types: the quadratic growth curve, the Mitcherlich growth curve, the linear-linear plateau spline model, and the quadratic-linear plateau spline model. Each model type was parameterized to create three different model ranges, and for each range, data were generated from populations with three different standard deviations. The existence of unique dose-response curves is assumed; thus, all the procedures compared in this paper require that the data have been modeled by a polynomial or nonlinear regression model. An attempt was made to fit each generated data set with each of the four model types. Maximum effective dose estimation procedures were applied to a data set only when the data were adequately described by a given model. The stimulation indicated that the estimate of the maximum effective dose is influenced more by the choice of model than by the method of estimation. Because of the consistently low estimates produced when the data were modeled by the linear-linear plateau spline, this model is not recommended for use an maximum effective dose estimation experiments. The simulation also demonstrated that the design failed to provide sufficient information about the form of the dose-response curve. Designs with more than four dose levels should be considered.

Sensory evaluation of beef-flavor-intensity, tenderness, and juiciness among major muscles.

Twelve muscles from eight USDA Select/Choice grade steers were evaluated for beef-flavor intensity, tenderness, and juiciness. The biceps femoris, psoas major, gluteus medius, semimembranosus, and triceps brachii were similar in beef-flavor-intensity (P > 0·05) and were ranked as the most intensely flavored of all muscles. The rectus femoris, longissimus lumborum, serratus ventralis, infraspinatus, semitendinosus, pectoralis profundus, and supraspinatus generally were less intense in beef-flavor than the other muscles and were ranked from highest to lowest intensity in that order. The psoas major was the most tender (P > 0·05) followed by the infraspinatus, longissimus lumborum, and rectus femoris, which were similar (P > 0·05). Generally, muscles from the chuck and loin were juicier than those from the round.

Comparisons of the effect of electrical stimulation methods on postmortem pH decline in beef muscle.

Results of four electrical stimulation (ES) studies were summarized to demonstrate the impact of different ES parameters on pH decline patterns in postmortem M. longissimus thoracis et lumborum. Postmortem pH decline was modeled as a non-linear function of time, and estimates of minimum obtainable pH, pH decline rates, and time to reach pH 6·0 were compared for each study. The decline model for study 4 (AC, 60 Hz, 50 V; 5 min post mortem) had a larger (P < 0·05) estimate for decline rate than that for study 1 (AC, 60 Hz, 400 V; 1 h post mortem) and the control (non-stimulated) data. The model estimate of time to pH 6·0 (0·56 h) for study 4 was the shortest (P < 0·05) for all treatments. Different ES parameters produce different pH decline patterns post mortem and, therefore, may impact product quality and fabrication and chilling protocols adopted in fresh beef processing.

Longevity of rabies antibody titre in recipients of human diploid cell rabies vaccine.

Sera from individuals across the USA and Peace Corps Volunteers (PCV) were assayed for neutralizing antibody to human diploid cell rabies vaccine (HDCV). A pairwise comparison between intramuscular (i.m.) and intradermal (i.d.) administration, PCV and non-PCV, revealed statistically significant differences between i.m. and i.d. for PCV and non-PCV, and between PCV and non-PCV for i.d. and i.m. administration. Survival analysis and frequency tables employing chi 2 tests determined that the percentage probability of maintaining an adequate titre from 1.5-2.0 years after primary vaccination was 99% in non-PCV i.m., 93% in non-PCV i.d., 88% in PCV i.m., and 64% in PCV i.d.

Landing pattern of stable flies (Diptera: Muscidae) on the alsynite cylinder trap: effect of wind speed and direction.

The distribution of stable flies, Stomoxys calcitrans (L.), caught on adhesive-coated Alsynite cylinder traps indicated that a significantly higher proportion of flies landed on the side most protected from the wind, and that flies were distributed equally on both sides of the traps bisected by the direction of the prevailing wind, and that the proportion of trapped flies decreased significantly with height on the trap. The landing pattern of house flies, Musca domestica L., appeared to differ from that of stable flies. As wind speed increased, the proportion of stable flies landing on the lower and downwind parts of the trap increased.

Autoregressive errors with a repeated measures design in clinical trials.

Repeated measures designs are common in clinical trials where recordings on a patient are made repeatedly over time. A basic assumption for the analysis of repeated measures designs is that a common correlation structure between observations for a given patient exists. When several observations are made for each patient this assumption may be tenuous at best. This article presents a pragmatic approach for combining a repeated measures design with a first-order autoregressive error component. A method of filtering the observed data to account for the autoregressive structure of the errors is considered. The effect on the analysis of variance results after extraction of the autoregressive component is seen by comparison of ANOVA summaries.