Eggs play important roles as food resources and nutraceuticals, to alleviate malnutrition and to improve health status in the world. Since free amino acids contribute to the nutritional values and food tastes, we investigated a total of 81 eggs from five chicken breeds, which are Australorp, Nagoya (NGY), Rhode Island Red (RIR), Shamo (SHA), Ukokkei, and two F1 hybrids (NGYxRIR and SHAxRIR) to test impact on genetic differences in 10 egg traits, 20 yolk amino acid traits, and 18 albumen amino acid traits. One-way ANOVA revealed significant breed effects on 10 egg traits, 20 yolk amino acid traits, and 15 albumen amino acid traits. Moreover, a significant heterosis effect on yolk aspartic acid was identified. In addition, positive correlations were found broadly among traits within each trait category (egg traits, yolk amino acid traits, and albumen amino acid traits), whereas there were basically no or weak correlations among the trait categories. These results suggest that almost all traits can be dramatically modified by genetic factor, and there will be partially independent production systems of amino acids into yolk and albumen. Since there will be typical quantitative genetic architecture of egg contents, further genetic analyses will be needed.

Background Japanese indigenous chicken breeds are often used to improve meat quality rather than broilers in the Jidori industry. There are sometimes severe crowding accidents caused by many birds frightened by environmental stimuli. To prevent the economic loss, the chickens need to be more gentle, tame, and imperturbable. Methods In this study, a new handling test for tameness in adult chickens in individual cages was performed with 100 birds from each sex of Shamo, Rhode Island Red, Nagoya, Australorp, and Ukokkei, as well as 10 hens of F1 hybrid between Shamo and Rhode Island Red, to measure both active and passive tameness. We counted the number heading toward human hands (heading) and retreating in other directions (avoiding) in both active and passive tameness phases, as well as the number of steps taken (step) during the handling test. Results Male chickens exhibited higher avoidance behavior than females. Nagoya females displayed the lowest level of avoidance behavior, which implies passive tameness. In terms of active tameness, a variety of phenotypes can be obtained in different combinations of breed and sex. These results suggested the handling test will be good method for rapid screening of individual differences in tameness. In addition, there were heterosis effects on avoidance and locomotive behaviors. Since F1 is often used in the Jidori industry, the breeders should be tested not only for meat production but also for tameness. Conclusions In the future, combining both the behavioral screening and the population genomics will establish typical evidence about mechanisms of tameness and domestication in animals.

The aim of the study was to test the effect of high moisture ear corn (HMEC) and high moisture shelled corn (HMSC) feeds on laying hen performance. A total of 108 Rhode Island Red laying hens were divided by body weight and performance into 12 blocks (9 in each). Each block was assigned to one of three dietary treatments. The hens were fed one of three experimental diets containing 48.0% commercial laying hen diet (CON), 55.7% HMEC (EC) or 48.5% HMSC (SC) on a dry matter (DM) basis. All diets were isocaloric (2.80 mega calorie (Mcal) of (metabolizable energy (ME)/kg of DM) and isonitrogenous (15.5% CP of DM). DM Feed intake (139 to 148 g DM/d per hen), egg production rate (79 to 85%), egg mass (47.6 to 51.2 g/d per hen) and feed utilization (2.7 to 3.1 g of feed DM/g of egg) were not affected by diet. Body weight for the SC diet was significantly less than that for the CON diet ( P <0.05). This was possibly due to the low feed intake during weeks 1 and 2 because of the short adaptation period to the experimental diet. The body weight loss of hens fed the SC diet may not have occurred when there had been a sufficient adaptation period. Eggshell strength (3.27 to 3.52 kg/cm 2 ) and Haugh unit (80.0 to 83.6) were not affected by diet. In conclusion, HMEC and HMSC diets do not significantly affect laying hen performance and can be used as a main ingredient of the laying hen diet.