γ-aminobutyric acid (GABA) is a natural stress-reducing substance and is actively used as a human health supplement. However, minimal research has been conducted on its use in cattle. This study was conducted to evaluate the effects of GABA on the growth performance, complete blood count, blood metabolites, and carcass characteristics of fattening Hanwoo steers. Twenty-one fattening steers were randomly assigned to one of three treatments: control (basal diet: concentrate feed + rice straw), T1 (basal diet + GABA supplement at 0.8% of feed/head/day), and T2 (basal diet + GABA supplement at 1.6% of feed/head/day). Feed intake and conversion ratio did not differ among the treatments. However, the average daily gain during the early fattening period increased linearly to 0.80 kg, 0.86 kg, and 0.92 kg in the control, T1, and T2 groups (p<0.05). Plasma γ-glutamyl transferase (37.5, 58.2, 42.8 U/ℓ) and creatinine (1.32, 1.34, 1.49 ㎎/㎗) levels in the GABA supplement group were increased compared to those in the control group. The carcass weight (422.7, 427.1, 454.1 kg), rib eye area (86.67, 92.57, 91.14 cm2), and marbling score (3.67, 4.29, 4.14) were numerically higher in the GABA supplement group than in the control group. Thus, GABA supplementation positively affected the average daily gain and carcass characteristics of Hanwoo steers. However, the effect of the GABA supplement level of GABA was small, and further research using rumen-protected coating technology on GABA is necessary.

This study investigated the effects of π-ray treated feeds on the growth performance, carcass composition, internal organ weight, and sensory evaluation of broilers. One hundred and eighty broiler chicks were used as experimental animals. These were divided into four treatment groups according to the π-ray treated feed supplement level: 0% (control) 1%, 3%, and 5%. The π-ray treated feeds did not significantly affect on the body weight gain (2,484–2,602 g), feed intake (4,747–4,944 g), and feed efficiency (1.90–1.98) in broilers (p>0.05). Also, carcass protein (20.2–20.4%) and fat (4.6–4.9%) contents were not affected. The lengths (178.0, 182.7, 198.0, and 190.3 cm) and weights (38.4, 41.2, 44.2, and 38.9 g/kg of body weight) of the small intestine were slightly but not significantly higher in the π-ray treatments than in the control. Further, there were no overall effect of the π-ray treatment on the abdominal fat pad (2.3, 2.1, 2.1, and 1.8%), and cecum (6.7, 4.0, 5.6, and 6.0 g/kg of body weight) and gizzard (16.8, 15.2, 18.0, and 16.6 g/kg of body weight) weights of the broilers in the present study (p>0.05). The stickiness (2.25, 4.25, 4.50, and 4.38) and flavor (2.44, 4.25, 4.31, and 4.38) of cooked breast meat were higher in the π-ray treatments than in the control (p<0.01). This study also found that, in humans, eating cooked breast meat of broilers that were fed π-ray treated feeds had a positive effect on the blood circulation in the capillaries. Thus, the findings of this study suggest that dietary π-ray treatment has a positive effect on the sensory evaluation of broilers, without any negative effect on their body weight gain, feed intake, and feed efficiency, and that the consumption of these broilers is beneficial for humans on their blood circulation.

본 연구는 사양체계 및 TMR의 NDF 수준이 번식용 젖소 육성우의 혈중 대사물질 농도 변화에 미치는 영향을 검토하고, 에너지, 단백질, 지질 및 간 기능 관련 지표 대사물질의 농도를 토대로 영양 상태를 관리하기 위한 기초자료를 제공하기 위해 수행되었다. 공시동물은 번식용 젖소 육성우 50두를 공시하였으며, 시험구 배치는 사양체계에 따라 TMR 처리구(TMR) 및 배합사료 + 혼합 조사료 처리구(CON)의 2처리로 하였으며, TMR의 NDF 수준에 따라 53% 이상(T1), 50 ∼ 53%(T2) 및 50% 이하(T3)로 3처리 하였다. 혈중 GLU 농도는 사양체계에 영향을 받지 않았지만, NDF 수준이 감소될수록 유의적으로 증가하였다(p<0.05). 사양체계가 혈중 단백질 관련 대사물질 농도에 미치는 영향은 없었으며, NDF 수준이 낮아질수록 혈중 ALB 농도가 증가되는 결과를 보였다(p<0.05). 혈중 CHOL 농도는 TMR 보다 CON 처리구에서 높았으며 (p<0.05), NDF 수준이 낮을수록 증가되는 결과가 나타났다. 혈중 지질 농도는 TMR 보다 CON에서 높았으며, NDF 수준이 낮아질수록 높게 나타났다. 혈중 ALT 농도는 T3구가 T1 및 T2구에 비해 유의적으로 낮게 나타났다(p<0.05). 따라서 본 연구의 결과에서 사양체계 및 TMR의 NDF 수준은 번식용 젖소 육성우의 혈중 대사물질 농도 변화에 영향을 미칠 수 있지만, 사료섭취량 및 영양성분 수준을 고려할 필요가 있을 것으로 판단된다.

The safety management of feeds has become a very important factor for food safety and legislation and system improvement are being implemented to prevent the hazardous factors from livestock products. The range of heavy metals in feed hazardous factors was similar among countries, but the As maximum limit was strengthened in Korea compared to China. Regulation of residual pesticide and radioactivity was only controlled in Korea. The range and maximum limit of mycotoxin were strictly controlled in China compared to Korea. In order to enhance the feed safety in Korea, it is necessary to improve the policy, strengthen the range of the feed hazard and the maximum limit and carry out the research related to the feed safety.