BACKGROUND AND PURPOSE:The training to acquire or practicing to perform a skill, which may lead to structural changes in the brain, is called experience-dependent structural plasticity. The main purpose of this cross-sectional study was to investigate the presence of experience-dependent structural plasticity in mathematicians' brains, which may develop after long-term practice of mathematic thinking.

Certain meat quality traits of guinea fowl that were reared in two production systems were determined in this study. Grey guinea fowl were reared in free-range and barn conditions. Birds were slaughtered at 14, 16 and 18 weeks old to determine meat quality traits. Some digestive traits were also determined. The type of production system affected the yellowness of breast meat significantly, and guinea fowl reared in the freerange system had yellower breast meat. The pH of both breast and thigh meat increased at older ages. Water-holding capacity, cooking loss and drip loss of breast and thigh meat were not affected by production system. Drip loss of meat decreased at older slaughter ages. The ratios of digestive system organ weights to body weight mostly decreased at older ages.

The current study investigated the effect of chick body (rectal) temperature during the post-hatch handling period on body weight (BW) loss, yolk sac utilization, organ weights, and broiler live performance. Hatching eggs were obtained from a commercial flock of Ross 308 broiler breeders at 44 wk of age. A total of 384 chicks were separated into 3 groups during the 12 h post-hatch handling period: control, high and low temperature groups, with average body temperatures of 40.0, 42.6, and 38.1°C, respectively. Residual yolk sac weight was not affected by temperature group, whereas the weights of organs such as the heart, gizzard, proventriculus, and bursa of Fabricius were significantly lower in the high body temperature group than in the control and low body temperature groups. BW was significantly lower at placement in chicks in the high temperature group than in chicks in the control and low body temperature groups due to greater weight loss during the post-hatch handling period (P ≤ 0.05). Lower BW was maintained in the chicks in the high body temperature group than in the chicks in the other 2 groups until the end of the experiment at 35 d (P ≤ 0.05) because chicks in the high temperature group consumed less feed throughout the experiment (P ≤ 0.05). Feed conversion ratio (FCR) and mortality were numerically greater in the high body temperature chicks than in the control group, whereas FCR and the mortality in the low body temperature chicks were intermediate at 35 d. The results of the present study indicate that day-old chicks with high body temperatures (42.6°C) exhibited a greater percentage of BW loss due to dehydration and lower organ weights during the 12 h post-hatch handling period, which was followed by significantly poorer broiler performance. There were no significant differences in performance between the chicks in the control (40.0°C) and low (38.1°C) body temperature groups. In conclusion, day-old chicks are more sensitive to higher body temperatures than to lower temperatures during the post-hatch handling period.

1. A total of 400 Alectoris chukar partridges were reared in either barn or free-range production systems and slaughtered at 14, 16 or 18 weeks of age in order to determine the effects of production system, age and gender on carcass traits (live weight, carcass weight, carcass yield, carcass part and edible inner organ percentages at slaughtering) and meat quality (L*, a* and b* meat colour and pH). 2. Production system had a significant effect on both slaughter traits and meat quality. 3. Partridges raised in barn conditions had higher live weights and carcass weights whereas meat quality was better in birds raised in the free-range system.

Successful incubation affects the number of healthy chicks in all poultry species. This study examined the effect of eggshell thickness on the hatching rates of guinea fowl and pheasant eggs. In total, 964 guinea fowl and 1,728 pheasant eggs were used in the study. Eggshell thickness was measured directly with an ultrasound gauge. Thicknesses ranged between 0.27-0.47 mm in guinea fowl and 0.24-0.49 mm in pheasant eggs. Incubation periods were 28 days for guinea fowl and 25 days for pheasant eggs. At the end of the incubation period, unhatched eggs were broken to identify the causes of embryonic mortality. Eggs were classified as thin-, medium-and thick-shelled, and hatching rates were calculated as a function of eggshell thickness. Differences in hatching rates of guinea fowl and pheasant eggs with different shell thicknesses were not statistically significant (p>0.05).