This study was conducted to investigate the effects by supplementing concentrates during the late fattening phase in TMR (total mixed ration) feeding of Korean steer on the performance, carcass traits, physico-chemical characteristics and sensory test of the longissimus dorsi muscle. Eight Korean steers (24 months of age) averaging 604 kg in body weight were fed the TMR (Control) or the TMR supplemented with concentrates (TMR+conc.) until 30 months of age, then they were slaughtered. Steers fed the TMR supplemented with concentrates had a higher (p<0.05) intakes of dry matter and TDN (total digestible nutrient), carcass weight and marbling score compared to those fed TMR only, but carcass grade did not differ (p>0.05) between treatments. Amino acid concentration of the longissimus dorsi muscle did not differ between treatments, However, the highest concentrations were for glutamic acid and lowest for cystine; further, and the content of essential amino acids was highest for lysine, leucine, threonine, arginine, and isoleucine in that order. Cis-oleic acid and arachidonic acid of fatty acids in the longissimus dorsi muscle were higher (p<0.05) in the control condition compared to TMR+conc. The contents of oleic acids, palmitic acid, stearic acid constituted about 88% of the total fatty acids. Although the physico-chemical characteristics of the longissimus dorsi muscle did not significantly differ between treatments (p>0.05), but the sensory test results were lower for the TMR+conc. condition. These results suggest that supplementing concentrates during the late fattening phase of Korean steers resulted in increasing the carcass weight and marbling score. However, the cis-oleic acid content of the longissimus dorsi muscle was decreased as a result of supplementing concentrates, which could affect negatively in meat sensory evaluation.

The feeding habits of the bighead croaker Collichthys niveatus were studied using 745 specimens collected by bottom trawl net in the West Sea, Korea, in April and October of 2016, 2017 and 2018. The size of C. niveatus ranged from 4.8 to 16.0 cm in total length. The stomach contents analysis indicated that C. niveatus consumed mainly euphausiids and copepods. C. niveatus consumed mainly euphausiids and copepods in all size classes. The dietary compositions of C. niveatus was not significantly different among size classes (One-way ANOVA, P > 0.05). As body size of C. niveatus increased, the mean weight of prey per stomach (mW/ST) tended to increase.

The purpose of this study was to determine the effects of mixed or split-sex feeding on growth performance and behavior of Korean native chickens. Three variants of the sex ratio, FO (female only), MO (male only) and MI (mixed) were tested in Korean native chickens (Hanhyop 3) that were between the ages of 7 and 91 days. Body weight gain was the highest (p<0.05) in the MO treatment and the lowest (p<0.05) in the MI treatment. The feed intake (FI) of birds in the MO treatment was higher (p<0.05) than that of birds in the MI treatment during days 14-21, also MO treatment was higher (p<0.05) than that of birds in the MI treatment during days 21-28. However, the FI of birds in the MI group was higher (p<0.05) than that of birds in FO treatment during days 35-42. The behavioral frequency of walking, drinking, and aggressive pecking were not affected by sex ratio treatment. The behavioral frequency of feeding was higher in the FO treatment than that of birds in the other treatments. The comfort time of birds in the MI treatment was longer (p<0.05) than that of birds in the other treatments. The behavioral frequency of pecking was higher in the MO treatment than that of birds in the other treatments. The study suggests that when male and female Korean native chickens are reared together, sex ratio can influence growth performance and behavior frequency.

본 연구는 지난 50년간 (1969~2018년) 우리나라 연안 - 하구에서 수행된 어류먹이원 분석과 관련된 논문을 수집하여 현황을 파악하였다. 확인된 연구논문은 총 101편 이었으며, 이 중 국내 학회지에 발표된 논문은 81편, 보고서는 6편 그리고 국제 학회지에 발표된 논문은 14편 이었다. 발표된 연구 논문을 10년 단위로 나누어 보면, 1990~1999년에 21편 (19.4%; 2.1편±3.0/년 [평균±표준 편차]), 2000~2009년에 26편 (24.1%; 2.6편±2.3/년) 이후 크게 증가하여 2010~2018년에는 52편 (48.1%; 5.8편±2.3/ 년)의 논문이 출판되었다. 국내 연안 - 하구에서 어류먹이원 분석을 수행한 조사수역의 해역을 방위 (남해, 남 - 동해, 동해, 서해)로 나누어보면, 남해에서 65편 (69.1%)으로 가장 많은 연구가 이루어졌다. 그 뒤를 동해가 13편 (13.8%), 서해와 남 - 동해에서 각각 8편씩 (8.5%) 연구가 수행되었다. 조사 지역의 분포를 보면 광양만에서 18편 (24.3%)으로 가장 많은 연구가 수행되었으며, 가덕도에서 8편 (10.8%)으로 그 뒤를 이었다. 출간된 논문의 방법론적 특성을 보면, 먹이원 중요도나 생태적 지위의 범위를 나타내주는 지표 를 계산하는 방법은 총 14가지가 사용되었으며, 이 중 가장 많이 사용된 지수는 IRI (Index of relative importance) 와 Pi (Prey-specific abundance)였으며, E (electivity index) 와 Bi (dietary breadth index)가 그 뒤를 이었다. 총 11가지 통계적 방법을 사용하였으며 이 중 correlation analysis와 Bray-Curtis similarity matrix를 가장 많이 적용하였다. 생태학적 연구 주제 변화를 살펴보면 초기 논문들은 계절적 또는 조사 지점별 차이에 초점을 맞추고 있었으나, 2000년도 이후부터는 국제 학회지에 출판되기 시작한 논문들은 종간 경쟁 (competition), 동소성 (sympatric), 생태직위중첩 (niche overlap) 등과 같은 세부적인 생태학적 연구가 이루어졌다. 국내 학회지에 출판된 논문들의 경우 다소 정형화 된 형태로 연구가 수행되고 있었으며 조사되지 않은 종에 대한 기초자료 제공 형태가 주류를 이루고 있었는데, 향후 국내 학회지에 발표되는 연구논문에서도 종간 경쟁, 먹이 망 구조 파악 등과 같은 생태학적 주제를 반증할 수 있는 연구 방향이 지향되어야 할 것이다.

This experiment was conducted to investigate the effect of whole crop rice (WCR) based TMR on growth performance and carcass characteristics of Hanwoo steers. WCR “Yeongwoo”was harvested at yellow ripen stage and ensiled for 60 days. The crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), in vitro dry matter digestibility (IVDMD) and total digestible nutrient (TDN) content was 8.4 %, 28.0 %, 53.8 %, 72.4 % and 66.8 %, respectively. For silage quality, pH was 4.37 and lactic and butyric acid content were 2.84 and 0.04 % in DM. Sixteen Hanwoo steers (8-mon-old) were allocated into either a control (commercial TMR) and WCR-TMR (WCR-based TMR) group. The TMR were fed according to the feeding stage phase: growing (Initiate∼14 month), early fattening (15 month∼21 month) and late fattening (22 month∼30 month). The body weight of control group increased (P<0.05) until early fattening stage, but late growing stage of WCR-TMR group was higher than that of control (P<0.05). Average daily gain (ADG) was significantly greater (P<0.05) in WCR-TMR group (total 0.78 kg/head) compared to control (total 0.66 kg/head) except for late fattening stage. The marketing weight and carcass weight were higher in WCR-TMR group (726 vs 765 kg; 417.8 vs 450.4 kg). The back fat thickness (11.75 vs 13.00 mm), Longissimus dorsi area (88.00 vs 89.88 ㎠) and yield index (65.87 vs 64.30) were not different between the two groups (P>0.05) and also no difference in meat yield grade (A : B : C = 2 : 4 : 2). Marbling score (4.00 vs 4.13), meat color (4.75 vs 4.75), fat color (3.13 vs 2.88), texture (1.25 vs 1.50) and maturity (2.00 vs 2.00) were not significant difference between the two groups and meat quality grade (1++:1+:1:2:3=0:2:4:2:0) was also not different. In conclusion, TMR feeding based on WCR silage showed superiority in carcass yield and ADG compared to control TMR. It is considered that the use of WCR for feed is a necessary option for the substitution of the imported forages and the government's policy for rice production adjustment.

This study was conducted to investigate the effect of supplementary feeding levels on livestck and forage productivity and grazing intensity in Elk stags (Cervus canadensis). A fifteen 2-year-old Elk stags about 195 kg were randomly assigned to one of three dietary treatments (five animals per treatment). The dietary treatments consisted of a feeding concentrate of 1.0% of body weight (T1), 1.5% of body weight (T2) and 2.0% of body weight. Total dry matter intake (TDMI) was increased with increased with an increasing supplementary feeding levels. Average daily gain (ADG) were significantly increased with an increasing supplementary feeding levels (p<0.05) and reached a maximum on July and was lower in spring than autumn. The velvet antler production was no differences among treatment groups. Forage productivity of pasture and crude protein content were highest on May and decreased thereafter, however, crude fiber content was the reversed. The grazing intensity of Elk stags was increased in spring (38 to 59 head per ha) than summer and autumn (13 to 32 head per ha). The average grazing intensity of Elk stags ranged from 21 to 34 head per ha, which is affected by supplementary feeding levels. This result suggests that feeding supplementary diet at 1.5 % of body weight was needed to maintain the stable wight gain in antler growing periods and control the proper grazing intensity of Elk deer stags.

본 연구는 번식기에 논을 이용하는 저어새의 섭식행동에 논의 다양한 환경요소가 어떤 영향을 주는지 알아보고자 실시되었다. 2017년 4월부터 6월, 2018년 4월부터 6월까지 한 달에 3회씩 강화도 논을 대상으로 저어새의 개체수를 조사하였다. 저어새가 영향을 받을 것으로 예상되는 환경요소로 수심, 경작에 따른 논의 구조적 형태, 잠재먹이원의 생물량을 선정하여 측정하였고, 논의 환경에 따른 저어새의 섭식행동의 차이를 알아보기 위하여 관찰된 섭식행동을 촬영하였다. 조사결과 저어새는 번식기간 중 4월 말부터 5월 말까지 논에 가장 많은 수가 도래했다. 총 308마리의 개체 중 86.4%(n=266)가 섭식행동을 하고 있었고 90.6%(n=279)가 성조였으며, 물이 없는 논에서는 발견되지 않았다. 강화도 논의 생물량은 어류의 산란기가 시작되는 5월부터 크게 증가하였으며 저어새가 관찰된 논과 관찰되지 않은 논의 생물량은 유의한 차이가 나타났다. 저어새의 섭식행동 분석 결과 논에 생물량이 많아지는 시기에 저어새의 섭식효 율과 섭식성공률이 크게 증가하였고, 저어새의 분당 발걸음 수는 모내기를 한 논에서 크게 증가하였다. 분당 부리를 젓는 횟수는 섭식효율 및 섭식성공률과 상관관계가 없었고, 논의 구조적 형태와도 관련이 없었다.

Aedes albopictus is an invasive mosquito that can be found in all continents. This species, considered as secondary vector of Dengue virus, has recently been suggested to play a role in the transmission of Zika virus in several countries bordering Brazil. In this study, We surveyed the distribution, abundance and main micro habitats of Ae. albopictus in Koera. The main bloodmeal source of this mosquito was mammals (71%) followed by birds (26%), and fish (1%). In flavivius detection, no virus was detected in this mosquito, but a total of six Japanese encephalitis virus (JEV) positive pools were detected from Culex orientalis and Culex pipiens. To investigate the possibility of using Wolbachia, as one of biological control strategy, we investigated the distribution of Wolbachia infection in Ae. albopicutus according to geographical distribution. Over 99% of the collected this mosquitoes harbored Wolbachia.