In Wagyu beef, the marbling has been improved, and then the fat quality attracts attention. Recent researches of fat quality on eating quality has been progressed and were reviewed. Wagyu fat has high monounsaturated fatty acids composition including oleic acid mainly, and has low melting point. In the evaluation methods of fat quality, non-destructive, rapid technique by portable near infrared fiber-optic device is applied at meat markets in Japan. The fat measurements are used for the genetic improvement and the branding of Wagyu. In panel tests, Wagyu (pure breed in Japan) and foreign Wagyu (cross) meat have excellent values in flavor, tenderness and juiciness, and show high consumer preference. Wagyu fat with low melting point is related to the high texture and rich juiciness. Free oleic and linoleic acids are noted as a sixth taste substance to stimulate not only fat taste (oleogustus) but also sweet, umami tastes. While polyunsaturated fatty acids cause oxidative off-flavour, together with monounsaturated fatty acids become precursors such as lactones with sweet flavour and aldehydes with beef fat aroma. These findings showed that the fat quality of Wagyu is an important trait of the eating quality composed from texture, juiciness and flavor.

Taste sense plays an important role in controlling the feeding behavior of animals. Therefore, it is considered that understanding of the taste sensing systems in chickens can contribute to the feed design and feeding strategy in poultry farming. In this paper, we review the current progress of studies for the taste sensing systems in chickens, especially for chicken umami taste sensing. In the series of studies, it has been revealed that chickens have gustatory perception of umami taste, and expression of umami taste receptor in the taste bud cells of chickens. These results provide the idea that umami taste plays an important role in palatability of feed in chickens.

Skeletal muscle fibers are divided into two types, type1 (slow-twitch oxidative) and type2 (fast-twitch glycolytic) fibers. Type 1 fibers are rich in mitochondria, have high oxidative metabolism, and are resistant to fatigue. The increase of type1 fibers leads to the improvement of texture, functional ingredients and taste in meat. It was thought that the increase of type1 fibers was only caused by exercise training. We found that oleic acid treatment of skeletal muscle cells significantly increased the expression of type1 fibers marker protein (MyHC1), oxidative metabolic factors, and mitochondrial mass. Furthermore, intake of diets containing oleic acid for 4 weeks induced the increase of MyHC1 expression and improvement of running endurance in mice. In addition, we found that skeletal muscle characteristics were changed by fish oil, yamabushitake mushroom, and apple polyphenol. These results indicate that skeletal muscle characteristics can be regulated by food components.

A restricted-selection for increasing component traits with no change proportion-defined trait was studied by selecting for milk fat percentage as an example. For milk yield and milk fat yield, phenotypic means of 8,000kg and 304kg and coefficient of variation of 20% and 20%, respectively, heritabilities of 0.3 for milk yield and milk fat yield and their genetic and environmental correlations of 0.65 and 0.9, respectively, were used in a stochastic computer simulation. The genetic parameters for milk yield, milk fat yield, and milk fat percentage were estimated from these simulated data and then used to simulate data in a base population and to derive selection index coefficients. Selection was simulated using three relative desired gain indices : (1) milk yield : milk fat yield＝1 : 0.038, (2) milk yield : milk fat percentage＝1 : 0, and (3) milk fat yield : milk fat percentage＝1 : 0. The genetic gain of milk fat percentage in (1) was the smallest of the three methods. For component traits in (2) and (3), selected traits showed a greater genetic gain than non-selected traits. These results suggest that two component traits should be used rather than the ratio trait and a component trait for maximizing component characters with no change in proportion-defined character.

The data of fatty acid composition of intermuscular fat on the graded surface from 1,095 Japanese black cattle were collected both by the handheld fiber-optic near-infrared spectrometry (NIR method) and the gas chromatography (GC method). The phenotypic correlations of fatty acid composition between estimated by NIR method and GC method were high (0.76-0.81), and genetic correlations were also high (0.92-0.97). The heritability of fatty acid composition by GC method (0.64-0.71) was higher than NIR method (0.39-0.45). The predicted breeding values of paternal 121 sires about oleic, monounsaturated, and saturated fatty acid composition were highly correlated between GC method and NIR method.

This experiment was conducted to assess effects of dry matter intake (DMI) and feeding ratios of forage to concentrate (F : C) on the ruminal mat score (RMS) in dairy heifers using a repeated-ruminal-compression method. Twelve Holstein heifers (441.9 days old, BW : 414.5kg) were assigned to three treatment groups of four individuals each : group 1 was fed 100% grass haylage (GH) ad libitum and 1 kg/d concentrate, group 2 received 60% of the voluntary intake of group 1, and group 3 was fed an ad libitum diet with 2 : 8 of F : C (CONC diet). The experiment was conducted for 12 days with an adaptation period of 10 days ; the sampling period was 2 days. Animals were fed once per day at 08 : 00 hr. DMI, RMS, rumen fluid properties, and rumination time were recorded. RMS and rumen fluid were measured 0, 3, and 7 h after feeding. RMS measurement followed the method of Abe et al. (2016). One animal was held in a stanchion, and one person repeatedly compressed the lower part of the left abdomen ten times with one fist without removing the fist from the body surface so as to stir and mix solid and fluid in the rumen. During this procedure, the rumen content containing little forage quickly turns wavy, whereas the content with larger amounts of forage remains clay-like and hard even after compressing ten times. RMS was rated using a five-point scale : RMS 1 indicated a low degree of ruminal forage filling, and RMS 5 indicated a high degree of filling. DMI tended to be higher in the CONC group (9.7kg/d) than in the other groups (100% diet : 8.8kg/d, 60% diet : 5.5kg/d). Rumination time was longer in cows fed the 100% diet than in those fed other diets. At 0 and 7 h, RMS was higher in the 100% group than in the 60% group (0h : P<0.05 ; 7h : P<0.10), and the CONC group produced intermediate values. Rumen pH was lower and total VFA concentrations were higher in cows fed the CONC than in those fed the 100% group at 3 and 7 h. Rumination time was significantly positively correlated with RMS at 0 h (R²＝0.672 ; P＝0.002). Our results demonstrated that rumen fill can be estimated by measuring RMS.

Spontaneous oxidized flavor (SOF) is one of the most troublesome off-flavors of raw milk. It is empirically known that feeding high amounts of soybean curd residue (SBCR) is related to the occurrence of SOF. This study is aimed to investigate the effect of feeding SBCR on the development of SOF of milk. Ten Holstein cows were used in a crossover design. Cows were assigned to one of two diets which contained either 15% SBCR in dry matter (group T) or not (group C) for two weeks. Milk, rumen fluid, and blood samples were collected and analyzed. The strength of SOF by sensory evaluation (SOF score) was significantly increased in group T than group C (P<0.05), and hexanal concentration in milk, as a chemical indicator for fatty acid oxidization, tended to be higher in group T (P<0.10). Positive correlation coefficient between SOF and hexanal concentration in milk was observed (r＝0.90, P<0.05). In rumen fluid collected two hours after feeding, the molar percent of acetic acid was significantly lower (P<0.01), and the concentration of ammonium nitrogen was significantly higher (P<0.05) for group T than group C. The concentrations of blood urea nitrogen and milk urea nitrogen were significantly higher (P<0.01) for group T than group C. The composition of C18:1, C18:2 and C18:3 fatty acids in milk were higher for group T than group C (P<0.01). The concentrations of alpha-tocopherol, an antioxidant and oxidation catalyst copper in blood and milk were similar in both groups. These results indicate that intake of SBCR is related to the occurrence of SOF through increasing PUFA in milk.

This study was conducted to estimate textural properties, drip loss, and degree of curing of beef (M. triceps brachii) during curing by impedance measured using touch type electrodes. Steaks (20×20×50 mm) were cured with 6% (w/w) muscle weight of NaCl for 10, 20, 30, 40, 50, or 60 minutes. Various characteristics of the steaks were measured before and during curing : textual properties, drip loss, and impedance (at 1Hz, 120Hz, and 100kHz). Maximum load, cohesiveness, adhesiveness, load of gumminess, and drip loss did not vary significantly with curing time. Impedance at 1Hz before curing was significantly higher than after curing. Impedances at 120Hz and 100kHz before curing were significantly higher than those after 10 minutes of curing ; however, there were no differences in impedance among steaks cured for 10, 20, or 30 minutes. Impedances at 120Hz and 100kHz after 10 minutes of curing were significantly higher than those of steaks cured for 40, 50, or 60 minutes ; there were no differences in impedance among steaks cured for 40, 50, or 60 minutes. These results suggest that it is difficult to estimate textural properties and drip loss of beef during curing but that it is possible to estimate the degree of curing non-destructively by measuring impedance with touch type electrodes.