The effect of corn distiller's dried grains with solubles, ractopamine, and conjugated linoleic acid on the carcass performance, meat quality, and shelf-life characteristics of fresh pork following three different storage methods

The objective of this study was to evaluate dietary corn distiller's dried grains with solubles (DDGS), ractopamine hydrochloride (RAC), and conjugated linoleic acid (CLA) on growth performance, carcass and fat quality, and shelf-life of fresh pork from finishing pigs. Barrows (n = 72) were fed one of eight treatments consisting of two diet sources (corn-soy and corn-soy + 20% DDGS), two levels of RAC (0 and 7.4 ppm), and two levels of CLA (0 and 0.6%) for 28 days. Loins were portioned (n = 3) into one of three storage conditions (fresh, cold, frozen); each followed with seven days of retail display. Feeding RAC improved ADG and G:F (P < 0.05), whereas DDGS decreased belly fat firmness (P < 0.05). Dietary DDGS increased total polyunsaturated fatty acids in jowl and belly samples and increased Iodine Value (IV) (P < 0.05), but addition of CLA decreased IV. Dietary DDGS, RAC, or CLA had minimal impact on pork quality following varied storage methods.     

The potential of volatile organic compound analysis in cervicovaginal mucus to predict estrus and ovulation in estrus-synchronized heifers

Cervicovaginal mucus is a mixture of mucins, ions, salts, and water, the proportions of which change during the reproductive cycle. It is suspected that this mucus emits an important volatile signal indicative of the reproductive state of the female. The objective of this study was to identify volatile organic compounds (VOC) in bovine cervicovaginal mucus that are modulated during the estrous cycle and could potentially be used as biomarkers of estrus and ovulation. Cervicovaginal mucus was collected from crossbred beef heifers (n = 8), which were synchronized using an 8-d controlled internal drug release (CIDR) protocol and in which onset of estrus and time of ovulation were determined by visual observation and ultrasonography, respectively. Mucus samples were collected between 0 and 96 h after CIDR removal (estrus onset occurred at 49.1 ± 3.3 h after CIDR removal). A validation study was performed on an independent group of 15 heifers from which cervicovaginal mucus samples were collected every 8 h from 40 to 80 h after CIDR removal. The VOC in mucus were identified using gas chromatography-mass spectrometry and selected compounds were quantified using selected-ion flow-tube mass spectrometry. The presence of 47 VOC was detected in mucus samples by gas chromatography-mass spectrometry with those exhibiting highest abundance including 2-butanone, acetone, 2-pentanone, 4-methyl-2-pentanone, 1-(1-methylethoxy)-2-propanone, ethanol, 2-methyl-2-propanol, and 2-butanol. All VOC peaked between 24 to 47 h after the onset of estrus (ovulation occurred 26.6 ± 5.6 h after estrus onset). Two VOC, 2-pentanone and 4-methyl-2-pentanone, exhibited a significant increase at the onset of estrus, whereas concentration of 2-butanone increased significantly just after estrus onset, indicating that these VOC may be used as putative biomarkers of estrus. The results of our study may contribute to the development of a sensor device based on VOC to aid the detection of estrus and ovulation in cattle, with particular relevance for the dairy industry where the majority of females are bred by artificial insemination.     

Prediction of genetic merit for live weight and body condition score in dairy cows using routinely available linear type and carcass data

Accurate estimates of genetic merit for both live weight and body condition score (BCS) could be useful additions to both national- and herd-breeding programs. Although recording live weight and BCS is not technologically arduous, data available for use in routine genetic evaluations are generally lacking. The objective of the present study was to explore the usefulness of routinely recorded data, namely linear type traits (which also included BCS but only assessed visually) and carcass traits in the pursuit of genetic evaluations for both live weight and BCS in dairy cows. The data consisted of on-farm records of live weight and BCS (assessed using both visual and tactile cues) from 33,242 dairy cows in 201 commercial Irish herds. These data were complemented with information on 6 body-related linear type traits (i.e., stature, angularity, chest width, body depth, BCS, and rump width) and 3 cull cow carcass measures (i.e., carcass weight, conformation, and fat cover) on a selection of these animals plus close relatives. (Co)variance components were estimated using animal linear mixed models. The genetic correlation between the type traits stature, angularity, body depth, chest width, rump width, and visually-assessed BCS with live weight was 0.68, ?0.28, 0.43, 0.64, 0.61, and 0.44, respectively. The genetic correlation between angularity and BCS measured on farm (based on both visual and tactile appraisal) was ?0.79; the genetic and phenotypic correlation between BCS assessed visually as part of the linear assessment with BCS assessed by producers using both tactile and visual cues was 0.90 and 0.27, respectively. The genetic (phenotypic) correlation between cull cow carcass weight and live weight was 0.81 (0.21), and the genetic (phenotypic) correlation between cull cow carcass fat cover and BCS assessed on live cows was 0.44 (0.12). Estimated breeding values (EBV) for live weight and BCS in a validation population of cows were generated using a multitrait evaluation with observations for just the type traits, just the carcass traits, and both the type traits and carcass traits; the EBV were compared with the respective live weight and BCS phenotypic observations. The regression of phenotypic live weight on its EBV from the multitrait evaluations was 1.00 (i.e., the expectation) when the EBV was generated using just linear type trait data, but less than 1 (0.83) when using just carcass data. However, the regression changed across parities and stages of lactation. The partial correlation (after adjusting for contemporary group, parity by stage of lactation, heterosis, and recombination loss) between phenotypic live weight and EBV for live weight estimated using the 3 different scenarios (i.e., type only, carcass only, type plus carcass) ranged from 0.38 to 0.43. Although the prediction of phenotypic BCS from its respective EBV was relatively good when using just the linear type trait data (regression coefficient of 0.83 with a partial correlation of 0.22), the predictive ability of BCS EBV based on just carcass data was poor and should not be used. Overall, linear type trait data are a useful source of information to predict live weight and BCS with minimal additional predictive value from also including carcass data. Nonetheless, in the absence of linear type trait data, information on carcass traits can be useful in predicting genetic merit for mature cow live weight. Prediction of cow BCS from cow carcass data is not recommended.     

Establishment of the mammalian membrane block to polyspermy: evidence for calcium-dependent and -independent regulation

One crucial result of egg activation is the establishment of blocks on the zona pellucida and the egg plasma membrane to prevent fertilization by additional sperm. The mechanism(s) by which a mammalian egg regulates the establishment of the membrane block to polyspermy is largely unknown. Since Ca(2+) signaling regulates several egg activation events, this study investigates how sperm-induced Ca(2+) transients affect the membrane block to polyspermy, building on our previous work (Biology of Reproduction 67:1342). We demonstrate that mouse eggs that experience only one sperm-induced Ca(2+) transient establish a membrane block that is less effective, than in eggs that experience normal sperm-induced Ca(2+) transients but that is more effective than in eggs with completely suppressed [Ca(2+)](cyt) increases. Sperm-induced increases in [Ca(2+)](cyt) regulate the timing of membrane block establishment, as this block is established more slowly in eggs that experience one or no sperm-induced Ca(2+) transients. Finally, our studies produce the intriguing discovery that there is also a Ca(2+)-independent event that is associated with fertilization in the pathway leading to membrane block establishment. Taken together, these data indicate that Ca(2+) plays a role in facilitating membrane block establishment by regulating the timing with which this change in egg membrane function occurs, and also that the membrane block differs from other post-fertilization egg activation responses as Ca(2+) is not the only stimulus. The membrane block to polyspermy in mammalian eggs is likely to be the culmination of multiple post-fertilization events that together modify the egg membrane's receptivity to sperm.     

Verbal deception from late childhood to middle adolescence and its relation to executive functioning skills.

The present investigation examined 8- to 16-year-olds' tendency to lie, the sophistication of their lies, and related cognitive factors. Participants were left alone and asked not to look at the answers to a test, but the majority peeked. The researcher then asked a series of questions to examine whether the participants would lie about their cheating and, if they did lie, evaluate the sophistication of their lies. Additionally, participants completed measures of working memory, inhibitory control, and planning skills. Results revealed that the sophistication of 8- to 16-year-olds' lies, but not their decision to lie, was significantly related to executive functioning skills. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

When all signs point to you: Lies told in the face of evidence.

Young children's ability to tell a strategic lie by making it consistent with the physical evidence of their transgression was investigated along with the sociocognitive correlates of such lie-telling behaviors. In Experiment 1, 247 Chinese children between 3 and 5 years of age (126 boys) were left alone in a room and asked not to lift a cup to see the contents. If children lifted up the cup, the contents would be spilled and evidence of their transgression would be left behind. Upon returning to the room, the experimenter asked children whether they peeked and how the contents of the cup ended up on the table. Experiment 1 revealed that young children are able to tell strategic lies to be consistent with the physical evidence by about 4 or 5 years of age, and this ability increases in sophistication with age. Experiment 2, which included 252 Chinese 4-year-olds (127 boys), identified 2 sociocognitive factors related to children's ability to tell strategic lies. Specifically, both children's theory-of-mind understanding and inhibitory control skills were significantly related to their ability to tell strategic lies in the face of physical evidence. The present investigation reveals that contrary to the prevailing views, even young children are able to tell strategic lies in some contexts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Numerical analysis of critical state behaviors of granular soils under different loading conditions

Discrete element method is used to simulate granular assembly behaviors with different initial conditions under three different loading conditions—plain strain, conventional triaxial compression, and direct shear. Different deformation modes of specimens with different conditions are presented. Some important parameters of the critical state theory are investigated. Uniqueness of the critical state line is checked which shows that there is no a unique critical state line for specimens with different initial void ratios under different loading conditions. Frictional angles and dilation angles of specimens with different conditions at critical state are compared. Void ratios and coordination numbers of specimens at critical state are studied. Anisotropies of the particle orientation and normal contact force at initial state, critical state, as well as the evolutions during shearing are analyzed. The anisotropy is shown to have significant effects on the soil behaviors and is related to the non-uniqueness of the critical state line. The developed numerical models can be used to study the micromechanics and microstructure of the specimen subjected to different loading conditions in the future.     

Small samples do not cause greater accuracy—but clear data may cause small samples: Comment on Fiedler and Kareev (2006).

Fiedler and Kareev (2006) have claimed that taking a small sample of information (as opposed to a large one) can, in certain specific situations, lead to greater accuracy—beyond that gained by avoiding fatigue or overload. Specifically, they have argued that the propensity of small samples to provide more extreme evidence is sufficient to create an accuracy advantage in situations of high caution and uncertainty. However, a close examination of Fiedler and Kareev's experimental results does not reveal any strong reason to conclude that small samples can cause greater accuracy. We argue that the negative correlation between sample size and accuracy that they reported (found only for the second half of Experiment 1) is also consistent with mental fatigue and that their data in general are consistent with the causal structure opposite to the one they suggest: Rather than small samples causing clear data, early clear data may cause participants to stop sampling. More importantly, Experiment 2 provides unequivocal evidence that large samples result in greater accuracy; Fiedler and Kareev only found a small sample advantage here when they artificially reduced the data set. Finally, we examine the model that Fiedler and Kareev used; they surmised that decision makers operate with a fixed threshold independent of sample size. We discuss evidence for an alternative (better performing) model that incorporates a dynamic threshold that lowers with sample size. We conclude that there is no evidence currently to suggest that humans benefit from taking a small sample, other than as a tactic for avoiding fatigue, overload, and/or opportunity cost—that is, there is no accuracy advantage inherent to small samples. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

An evaluation of fluidized-bed heating as a means of disinfesting wheat

Wheat of 14% m.c. containing all immature stages of Sitophilus oryzae (L.), Rhyzopertha dominica (F.) and Sitotroga cerealella (Oliv.) was exposed to air temperatures of 60, 70 or 80°C in a 10 kg capacity fluidized-bed operated with an airflow of 14.51 ls^?1 kg^?1 at 1.6 m s^?1. Exposures of 12, 6 and 4 min respectively produced grain surface temperatures of 59, 62 and 65°C and gave almost complete disinfestation. The required minimum exposure was determined by the heat tolerance of R. dominica which exceeded that of the other species. The moisture content of treated wheat was not changed appreciably and its baking quality was not impaired. Experiments with S. oryzae and R. dominica showed that the adults were also controlled by such exposures. The cost of fluidized-bed heating is discussed and appears to be comparable to that of recirculatory fumigation with methyl bromide.     

The influence of some biological and physical factors on the heat tolerance relationships for Rhyzopertha dominica (F.) and Sitophilus oryzae (L.) (Coleoptera: Bostrychidae and Curculionidae)

The influence of several biological and physical factors on the exposure time required to obtain a given level of mortality of immature Rhyzopertha dominica and Sitophilus oryzae exposed to air at 70 or 80°C in a fluidized bed of wheat was determined.The tolerances of five Australian populations of R. dominica differed little. In this species, median tolerance and variance increased as the age span of the exposed insects widened from 0–7 to 0–35 days. Acclimation of R. dominica at 22 or 32°C and S. oryzae at 15 or 30°C before exposure had no appreciable influence on heat tolerance.Changing the initial grain temperature from 32 to 22°C did not alter LT values for R. dominica. However, the LT_99.9s for both warm and cold acclimated S. oryzae in 15°C grain were greater than those in 30°C grain. The LT_99.9s for R. dominica in wheat of 14% m.c. exceeded those in 11.3% m.c. wheat. Heating curves showed that the time taken for cold or moist grain to reach a given high temperature was extended.