Using Natural Zeolite as a Feed Additive in Broilers' Diets for Enhancing Growth Performance, Carcass Characteristics, and Meat Quality Traits

BACKGROUND

Using natural zeolites as a food additive in poultry diets offers an intriguing perspective. The objective of this study was to investigate the effects of zeolite addition and particle size on broiler performance, carcass characteristics, meat quality, moisture of excreta and litter, and intestinal measurements during 35 days.

METHODS

A total of 560 1-day-old female Ross-308 broilers were divided into five treatment levels (0, 5, 10, 15, and 20 g zeolite/kg diet) (n = 16 replicates/treatment, n = 8 replicates /particle size of each treatment). Performance was calculated weekly. Carcass characteristics, meat quality, small intestine (SI) measurements, litter pH, and moisture content were determined on day 35.

RESULTS

Litter pH, breast redness, cooking loss, chewiness, total weight, and SI length were all affected by zeolite treatments (p < 0.05). Particle size had an impact on the gastric pH and texture analysis. Their interaction had an effect on color redness, litter pH, and cooking loss. Performance was unaffected by either the main or interaction effects.

CONCLUSION

Zeolite as a feed additive may be useful in broiler diets, particularly large particles. The performance and production efficiency factor improved numerically (p > 0.05) with increasing zeolite doses up to 10 g zeolite/kg diet.

Canonical Size in Haptic Drawings

This study aimed to test differences in drawn size of familiar objects of different physical size in haptic drawings produced by blindfolded sighted participants. Using two sizes of the foil sheets on which they made convex drawings, they drew one object per foil. The results showed that the size of drawings increased linearly with the rising rank of real-world size. Although larger drawings were created on larger foils than on smaller ones, the ratio of the object drawn size within the foil sheet size did not differ across foil sizes. Hence, canonical size-a phenomenon known so far from studies on the visual domain-revealed here in a task performed in the haptic domain.

Changing the Real Viewing Distance Reveals the Temporal Evolution of Size Constancy in Visual Cortex

Our visual system provides a distance-invariant percept of object size by integrating retinal image size with viewing distance (size constancy). Single-unit studies with animals have shown that some distance cues, especially oculomotor cues such as vergence and accommodation, can modulate the signals in the thalamus or V1 at the initial processing stage [1-7]. Accordingly, one might predict that size constancy emerges much earlier in time [8-10], even as visual signals are being processed in the thalamus. So far, the studies that have looked directly at size coding have either used fMRI (poor temporal resolution [11-13]) or relied on inadequate stimuli (pictorial illusions presented on a monitor at a fixed distance [11, 12, 14, 15]). Here, we physically moved the monitor to different distances, a more ecologically valid paradigm that emulates what happens in everyday life and is an example of the increasing trend of "bringing the real world into the lab." Using this paradigm in combination with electroencephalography (EEG), we examined the computation of size constancy in real time with real-world viewing conditions. Our study provides strong evidence that, even though oculomotor distance cues have been shown to modulate the spiking rate of neurons in the thalamus and in V1, the integration of viewing distance cues and retinal image size takes at least 150 ms to unfold, which suggests that the size-constancy-related activation patterns in V1 reported in previous fMRI studies (e.g., [12, 13]) reflect the later processing within V1 and/or top-down input from other high-level visual areas.

Size Matters: Are Physically Large People More Likely to be Violent?

A number of studies suggest that physical size is associated with violent behavior. However, few, if any, studies have examined this relationship using population-based samples. Moreover, limited evidence exists on the relationship between physical size and violence with respect to gender, race/ethnicity, and exposure to childhood maltreatment. The present study, using data from Waves I and II (N = 34,653) of the National Epidemiologic Survey of Alcohol and Related Conditions (NESARC), aims to address these gaps by comparing the prevalence of violent behavior among individuals in the top quintiles in height and weight with that of the general population. Significant associations were identified for both males and females between physical size and bullying/intimidation, intentional injury of other persons, and hitting someone so hard that they required medical attention. Stratified analyses revealed that the magnitude of the relationship between physical size and violence is greater among Hispanics than among non-Hispanic Whites and African Americans. Childhood abuse and neglect significantly moderated the relationship between physical size and violent behavior. While an important degree of variability can be observed with respect to gender, race/ethnicity, and exposure to child maltreatment, results indicate that, in general, physically larger individuals are more likely than their relatively smaller counterparts to be violent.

Children and Adults Use Physical Size and Numerical Alliances in Third-Party Judgments of Dominance

Humans and other social animals interact regularly with conspecifics as part of affiliative groups. Many of these interactions are cooperative, but many others involve competition for resources. Competitive exchanges are often resolved on the basis of dominance relationships, with higher-ranking individuals receiving priority access to desired goods. Although no single cue can establish permanent dominance relationships, there are some cues that predict dominance fairly reliably across context. In the present study, we focused on two such cues relevant to competing groups: (i) the physical sizes of individual members, and (ii) their relative number. Using a social competition task, we examined whether, and how, preschool-aged children and adults used differences in physical size and numerical alliances to judge which of two groups should prevail in a competitive exchange for a desired object. These judgments were made when either physical size or number differed between groups (Experiment 1), and when both were available but pitted against each other (Experiments 1 and 2). Our findings revealed that by 3 years of age, humans use multiple perceptible cues in third-party judgments of dominance. Our findings also revealed that 3-year-olds, like adults, weighted these cues flexibly according to the additional factor of overall group size, with the physical sizes of individuals determining dominance in smaller groups (e.g., 2 vs. 4 characters) and the relative number of individuals determining dominance in larger groups (e.g., 15 vs. 30 characters). Taken together, our findings suggest that a basic formula for determining dominance in competitive exchanges, which weights physical size of individuals and numerical alliances as a function of overall group size, is available to young children and appears fairly stable through to adulthood.