This study investigated the effect of dietary lysine and gamma-linolenic acid(GLA) levels on growth performance, carcass traits, and meat quality in finishing pigs. Pigs were provided with feed containing two different levels of lysine(0.45% and 0.75%) with three different levels of gamma-linolenic acid(0.0, 0.3, and 0.6%). Average daily gain(ADG) was significantly lower (p<0.01) in pigs provided with the lower level of lysine. In contrast, feed/gain(p<0.01), diet cost/gain(p<0.05), and intramuscular fat(p<0.01) were all significantly higher in pigs fed the lower level of lysine. Similarly, meat color scores(CIE L*, a*, and b*) and cooking loss were significantly higher(p<0.01) in pigs fed the lower level of lysine, whereas shear force(kg/2.5 inch2)was not affected by dietary lysine. The addition of GLA had no significant effect on any of the parameters measured. The results indicate that providing pigs with 0.45% lysine in their diet may help to increase intramuscular fat content, allowing the industry to produce pork products that meet consumer needs in Korea.

This study was carried out to investigate the comparison of meat quality of Korean native black porks and modern genotype pork fed high and low lysine levels of diets at growing and finishing stages during refrigerated storage after thawing. M. longissimus from Korean native black pigs (gilts) with a live weight of 65 kg and modern genotype pork (gilts) with a live weight of 110 kg were frozen at -80 ℃ for 1 month and placed in the dark room at 1℃ for 7 days after thawing. The moisture content was significantly lower in modern genotype pork fed high lysine level of diets than to the other treatments (p<0.05), but crude fat content was significantly higher in modern genotype pork fed high lysine level of diets (p<0.05). The pH value and sensory evaluation were significantly higher in Korean native black pork than to modern genotype pork (p<0.05), and the drip loss was significantly lower in Korean native black pork (p<0.05). CIE L*, ho and hunter L were significantly lower in modern genotype pork fed high lysine level of diets than to modern genotype pork fed low lysine level of diets (p<0.05). Myristate, palmitate and saturated fatty acid content were significantly lower in Korean native black pork fed high lysine level of diets than to Korean native black pork fed low lysine level of diet (p<0.05), but unsaturated fatty acid content and UFA/SFA ratio were higher in Korean native black pork fed high lysine level of diets (p<0.05). Consequently, as Korean native black pigs were fed high lysine level of diets at growing and finishing stages, saturated fatty acid content of pork increased but unsaturated fatty acid content and UFA/SFA ratio of pork decreased. And the water-holding capacity, color stability and sensory evaluation of Korean native black porks were better than those of modern genotype pork.

This study was carried out to investigate the comparison of quality characteristics of Korean native black porks fed high, medium and low levels of lysine diets at growing and finishing stages during refrigerated storage. M. longissimus from Korean native black pigs (gilts) with a live weight of 65 kg were placed in the dark room at 4℃ for 7 days and utilized for the quality measurements. The proximate composition, drip loss, TBARS value and sensory evaluation of raw and cooked meat were not affected by dietary lysine level. Korean native black pork fed low lysine diets showed the highest redness (a*) at day 7. Consequently, as Korean native black pigs were fed low lysine diets at growing and finishing stages, it was effective in color stability of porks.

This study was carried out to investigate the effect of feeding level of dietary lysine on the quality of Korean native black pork during cold storage (4℃). After 54 Korean native black pigs was fed by the high, medium, low lysine dietaries at 25 kg live weight, the M. longissimus from 6 carcasses (3 gilts, 3 barrows) slaughtered at 65 kg live weight stored at 4℃ for 7 days. The proximate composition, drip loss, cooking loss, sensory evaluation was affected by feeding level of dietary lysine. The pH value was significantly higher in high lysine treatment than in the other treatments until 5 days (p<0.05) and significantly lower in medium lysine treatment (p<0.05). The CIE L* value was significantly higher in gilts among high lysine treatment (p<0.05) and increased significantly in all treatments until 5 days (p<0.05). The CIE a*, b*, C* values were higher in low lysine treatment. The hardness, adhesiveness, springiness, cohesineness, guminess, chewiness were lower in low lysine treatment and those in 7 days were lower than in 0 day.

The present study was conducted to investigate effect of dietary protected amino acid on milk yield and composition in dairy cow using meta-analysis. Total 21 research papers were employed in analysis, and mixed model was used for the analysis of effects. Effect of protected methionine (PM) and combination of protected methionine and lysine (PML) were investigated under two different levels of dietary crude protein (CP, <18% and >18%). For performance of dairy cow, milk yield, milk composition including milk fat and protein content and yield and 4% FCM (fat corrected milk) production were used for analysis. In case of milk yield, a trend of increment was found at PM supplementation at low CP (P=0.055). However, the effect of PM at high CP was detected as not significant (P>0.05). In case of milk protein, inclusion of PM at low CP showed significant decrement (P<0.05). However, there was no significant effect of MP on milk protein at high CP (P>0.05). Supplementation of MP at high CP level showed significant increment of milk fat (P<0.05). MP supplementation represented significant increment of 4% FCM production (P<0.05) regardless of dietary CP levels. Effects of PML on milk yield and composition at both of low and high dietary CP were not significant in this study. However, it seem to be that there was a possible positive effect of MPL application at high dietary CP on performance of dairy cow.