• Journal of Animal Science and Technology
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• v.52 no.6
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• pp.499-504
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• 2010

This study was conducted to determine the effects of ruminally protected amino acid-enriched fatty acids (RPAAFA) on body weight gain, feed intake and carcass characteristics of fattening Hanwoo cows. Twenty eight Hanwoo cows, $6.0{\pm}1.7$ years old and weighing an average of $463.2{\pm}77.6\;kg$, were used for 4 months. Animals were fed a basal diet supplemented with RPAAFA at 0 g (control) and 100 g (treatment), respectively. Average daily gain, dry matter intake and feed conversion ratio were not different among the control and treatment. The supplementation of RPAAFA did not affect carcass weight and rib eye areas. Quality grade score ($1^{++}$, $1^+$ and 1) for treatment was higher in RPAAFA supplemented group compared with the control, whereas no differences appeared in meat color, fat color, texture and maturity. Thus present results indicate that supplementation of RPAAFA may be recommended for producing high quality beef from fattening Hanwoo cows.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.8
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• pp.1013-1021
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• 2010

This study was conducted to determine the effects of amino acid-enriched ruminally protected fatty acid (AARPFA) on plasma fatty acids and amino acids, growth performance and carcass characteristics of Korean native steers (Hanwoo) by simultaneous supply of fatty acids and limiting amino acids (methionine and lysine). Eighteen finishing Hanwoo steers, 18 months of age and weighing an average of $459.0{\pm}38.9\;kg$, were used for studies of the metabolism of plasma fatty acids and amino acids during supplementation of AARPFA. Also, 45 finishing Hanwoo steers, 16 months of age and weighing an average of $408.6{\pm}26.5\;kg$, were used for growth performance and carcass characteristics during supplemention of AARPFA. There were three treatments which comprised a basal diet supplemented with AARPFA at 0 g (T1), 50 g (T2) or 100 g (T3), respectively. Concentrations of saturated, unsaturated and total fatty acids in plasma were increased in T3 compared with other treatments (p<0.05). Concentrations of methionine and lysine in plasma were linearly increased with increasing levels of AARPFA (p<0.01). Average daily gain, dry matter intake and feed conversion ratio were not different among the treatments. Marbling score measured by ultra-sound scanning was higher in T3 than in T1 at 24 months of age (p<0.05). Rib eye area, back fat thickness, yield index and yield grade score were similar across the treatments. Marbling score and quality grade score were higher in T3 compared with other treatments (p<0.01). Thus, plasma fatty acids, methionine and lysine metabolism were affected by supplementing with 100 g of AARPFA which also had positive effects on marbling score and meat quality grade of finishing Hanwoo steers.