BackgroundRecently, as production costs have been increasing owing to rising feed prices worldwide, shortening the age of slaughter has been recognized as a way to increase farm income. In Korea, the raising period for Hanwoo steers is over 31 months with the delay of weaning and castration stated as one of the reasons for the increase in the raising period. Thus far, studies on age of weaning and castration have been conducted individually, and there have been no studies on the combined effects of weaning and castration ages on the growth performance and carcass characteristics in Hanwoo steers.MethodsWeaning ages were calculated at 80 or 130 days of age, and castration ages were calculated at 90 days and 180 days of age. Calves were allocated to one of the four treatment groups: W80C90 (weaning at 80 days of age and castration at 90 days of age), W80C180, W130C90, and W130C180.ResultsFor the entire experimental period, weaning and castration ages did not significantly affect growth performance of Hanwoo steers. In addition, weaning and castration ages did not affect the overall yield and quality traits of carcass in Hanwoo steers.ConclusionWeaning and castration ages had small effects on growth performance and carcass characteristics in Hanwoo steers. Therefore, the early weaning and castration ages are recommended to reduce the slaughter age without any negative effects on meat quality grade.

This study was conducted to investigate the effect of the total digestible nutrients (TDN) level of commercial concentrates on growth performance, carcass characteristics, and meat composition of late fattening Hanwoo steers. A total of 28 steers were randomly assigned to one of four dietary groups; T1 (73.30% TDN), T2 (74.50% TDN), T3 (76.40% TDN), and T4 (77.10% TDN). Average daily gain (ADG) was slightly but not significantly higher in the T2 than in the other treatments. Dry matter intake (DMI) and feed conversion ratio (FCR) were higher in the T2 than in the other treatments; however, the differences were not statistically significant. Carcass back fat thickness was thicker in the T4 and marbling score was higher in the T2 than in the other treatments; however, the differences were not statistically significant. The TDN level of concentrates had no effect on the physicochemical characteristics and fatty acid composition of the longissimus muscle. The finding of this study indicate that less than 74% or greater than 75% TDN in the commercial concentrate did not contribute to improve ADG, FCR, marbling score; therefore, in the present study, the recommendable TDN level in the commercial concentrate for late fattening period was 74% to 75% in terms of growth performance and marbling score of Hanwoo steer.

Objective This study was conducted to investigate the effects of dietary levels of tapioca residue on growth performance, carcass characteristics, and meat composition in Hanwoo steers. Methods Twenty-eight steers were randomly assigned to one of four dietary groups; T0 (0% tapioca residue), T6.7 (6.7% tapioca residue), T9 (9% tapioca residue), and T12 (12% tapioca residue). Results Supplementation with tapioca residue had no effect on overall growth performance. The concentration of plasma total cholesterol was higher in T6.7 than in other treatments (p<0.05). Dietary levels of tapioca residue did not affect carcass yield or the quality traits of Hanwoo steers. The lightness, redness, and yellowness of the longissimus muscle of Hanwoo steers were higher in T6.7 than in other treatments (p<0.05). Cohesiveness, gumminess, chewiness, and resilience were lower in T6.7 than in other treatments (p<0.05). Conclusion The results of the present study indicate that supplementation with tapioca residue does not exert any negative effects on growth performance, carcass characteristics, and meat composition in Hanwoo steers. However, as the dietary level of tapioca residue increased, the intake of concentrate intake decreased, and tapioca supplementation greater than 6.7% did not substantially improved the marbling score.

Background: Methane reduction technology has not yet been put into practical use because of problems such as reduced digestibility, increased costs, additives remaining and microbial adaptations. The objectives of this study were to evaluate the effects of allicin and illite supplementation on ruminal methane production, growth performance and carcass characteristics of the Hanwoo steers. Methods: For the in vitro experiment, 3 Hanwoo cows equipped with rumen fistula were used. The 28 Hanwoo steers were randomly assigned to one of the four dietary groups: control (CON), T1 (1.0% illite), T2 (0.1% allicin), or T3 (1.0% illite and 0.1% allicin). All data were analyzed using the generalized linear model procedure. Result: The methane production was rapidly increased for all the treatments after 8 h, but decreased compared to the control after 24 h (P less than 0.05) of incubation. There was no difference in the growth performance and carcass characteristics of steers among the treatments. Thus, allicin 0.1% and/or illite 1.0% have the potential to be used as natural feed additives to reduce methane production.

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