• Journal of Animal Science and Technology
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• 제65권6호
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• pp.1270-1289
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• 2023

This study evaluates how different feeding systems impact ruminal fermentation, methane production, and microbiota of Hanwoo steers native to Korea. In a replicated 2 × 2 crossover design over 29 days per period, eight Hanwoo steers (507.1 ± 67.4 kg) were fed twice daily using a separate feeding (SF) system comprising separate concentrate mix and forage or total mixed rations (TMR) in a 15:85 ratio. The TMR-feeding group exhibited a considerable neutral detergent fiber digestibility increase than the SF group. However, ruminal fermentation parameters and methane production did not differ between two feeding strategies. In addition, TMR-fed steers expressed elevated Prevotellaceae family, Christensenellaceae R-7 group, and an unidentified Veillonellaceae family genus abundance in their rumen, whereas SF-fed steers were rich in the Rikenellaceae RC9 gut group, Erysipelotrichaceae UCG-004, and Succinivibrio. Through linear regression modeling, positive correlations were observed between the Shannon Diversity Index and the SF group's dry matter intake and methane production. Although feeding systems do not affect methane production, they can alter ruminal microbes. These results may guide future feeding system investigations or ruminal microbiota manipulations as a methane-mitigation practice examining different feed ingredients.

• 농업과학연구
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• 제48권1호
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• pp.171-178
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• 2021

A comparative study was conducted to examine the effects of mixed and separate gender feeding on growth performance of Korean native chickens (KNC) against a white semi-broiler (WSB) and a commercial broiler (CB) over five weeks. 576 chicks were used with eight birds per cage in a randomized complete block design with 18 replicates per breed. For the KNC lines, three groups of male (M), female (F) and mixed-gender (FM) were used. Fresh water and feed were supplied on an ad-libitum basis. Birds were fed a standard starter (d 1 - 22) and grower diet (d 23 - 35). Body weight (BW), feed intake, and shank length (SL) were measured weekly. From the BW and feed consumed data, the average daily feed intake (ADFI), average daily gain (ADG), and feed conversion ratio (FCR) were calculated. The commercial broiler showed higher performance (p < 0.05) for all the indices measured for the entire period. The CB group consumed more feed and were more feed-efficient thus grew faster. This group was followed by the white semi-broiler and the KNC, in order. An intra-breed comparison for KNCs revealed that the males showed better growth performance with longer SL (p < 0.05) compared to the female and mixed-gender groups. The results showed that other than the breed type, mixed and separate gender feeding impacted on the growth performance of the two lines of Korean native chickens. Males for both lines of KNC generally performed better for the parameters measured, as determined by a greater BW and reduced FCR.

• Asian-Australasian Journal of Animal Sciences
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• 제6권1호
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• pp.91-97
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• 1993

This experiment was carried out to examine the effects of urea-treated rice straw feeding on the growth performance of crossbred Holstein heifers under different feeding conditions. In the first experiment, the animals were given diets having 2 levels of TDN and CP and 3 levels of crude fiber (22, 30 and 36%) which were formulated with urea-treated rice straw and concentrates. Daily weight gain of heifers was not different between 22% and 30% CF diets, but the reduction of TDN or CP level to 90% of the requirements decreased the weight gain. Fiber content of 36% also reduced the body weight gain. The reduction of TDN significantly reduced DM intake and increased feed conversion ratio. Feed cost per kg weight gain was significantly increased by an increase in CF to 36%. In the second experiment, separate feeding and total mixing feeding were compared. There were no significant differences between the two feeding systems in body weight gain although the possibility of superiority in SF to TMF remained. DM intake was not affected by the feeding system, but 30% CF diet gave higher DM intake. Feed cost per kg weight gain was lower in the 30% CF diet.

• Asian-Australasian Journal of Animal Sciences
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• 제16권10호
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• pp.1482-1486
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• 2003

In order to compare effects of feeding systems on rumen fermentation characteristics and nutrient digestion, steers were fed either total mixed ration (TMR) or separate concentrate-roughage ration (CR). Total tract digestibility of nutrients was higher in steers receiving TMR. Especially, DM, ADF and NDF in TMR were digested to a greater extent than those in CR. Rumen pH was not influenced by the feeding systems. Holstein steers on TMR had higher ruminal $NH_3$-N than those on CR. Feeding system did not alter VFA production but TMR feeding resulted in lower A/P ratio. TMR feeding tended to increase the number of bacteria and protozoa in the rumen fluid. Also steers fed TMR generally had higher fiber degrading enzyme activities, which might be the result of increased number of cellulolytic microbes in the rumen of animals on TMR. Our results indicate that TMR may provide more favorable condition for nutrient digestion both in the rumen and in the total tract of steers.

• 한국초지조사료학회지
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• 제33권2호
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• pp.131-138
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• 2013

본 연구는 국내에서 생산된 주요 동계 사료작물인 청보리 및 청호밀 사일리지를 이용하여 거세 한우의 비육후기(25~30개월 령) 용으로 조제된 TMR의 소 체내 이용성을 배합사료 및 볏짚으로 구성된 관행 사료와 비교하고자 반추위 누관이 장착된 소 3두를 이용하여 $3{\times}3$ Latin square design 방법으로 실시되었다. 시험동물에는 비육 후기용 배합사료 및 볏짚을 분리 급여하였거나 (대조구) 청보리 사일리지 TMR (BS-TMR) 또는 청호밀 사일리지 TMR (RS-TMR)을 급여하였다. 전체 채취시간에 걸쳐 반추위액의 pH, 암모니아 농도 및 총 휘발성지방산 농도는 시험사료간 차이가 없었다. Acetate ($C_2$)의 조성 비율은 사료 급여후 1시간에서 청보리 사일리지를 섭취한 처리구 (BS-TMR)에서 낮은 (p<0.033) 값을 제외하고는 대부분의 채취시간에서 시험사료 간 차이가 없었다. Propionate ($C_3$) 및 butyrate 조성비율과 $C_2/C_3$ 비율 역시 모든 채취시간에서 시험사료간 차이가 없었다. 사료 내 주요 성분의 반추위 유효분해율과 전장소화율은 전체 시험사료 간은 물론 BS-TMR과 RS-TMR 간에도 차이가 없는 것으로 나타났다. 본 대사시험 결과로 미루어보아 청보리 및 청호밀로 제조된 TMR의 급여 가치가 배합사료 및 볏짚의 분리급여와 차이가 없는 것으로 여겨진다.

• 한국유기농업학회지
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• 제27권3호
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• pp.365-380
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• 2019

본 연구는 봄에 출생한 송아지 10두(3.90±0.26개월령)와 가을에 출생한 송아지 10두(4.10±0.30개월령)를 약 24개월간 조사료와 농후사료를 분리 급여하거나 또는 TMR을 급여하여 분만 후의 유생산과 비유지속성을 조사하였다. 처리구는 사료 급여 형태와 분만계절의 2가지 요인으로 육성기에 조사료와 농후사료를 분리하여 급여하고 봄에 분만한 CS구, 육성기에 조농분리 급여한 후 가을 분만한 CF구, 육성기에 TMR을 급여한 후 봄에 분만한 TS구 그리고 육성기에 TMR을 급여하고 가을에 분만한 TF구의 4가지로 구분하였다. 육성기의 건물섭취량은 분만계절의 영향을 받아 가을에 분만한 구가 봄에 분만한 구보다 높게 나타났으나(P<0.01), 사료급여 방법에 의해서는 유의한 차이를 나타내지 않았다. CP 섭취량과 TDN 섭취량은 분만계절(P<0.05)과 사료급여(P<0.01)에 의해 유의한 영향을 받았으며 가을에 분만한 구가 봄에 분만한 구에 비해 약 1.2% 높게 나타났고 TMR 급여구가 조농분리 급여구보다 약 4.7%정도 높은 결과를 보였다. 평균 산유량과 9, 10개월차의 산유량은 사료급여 방법에 의해 유의한 영향을 받아 TMR 급여구(TS구, TF구)가 조농분리 급여구(CS구, CF구) 보다 높은 결과를 나타내었다(평균 P<0.05; 9개월차와 10개월차 P<0.01). 평균 비유지속성은 분만계절(P<0.05)과 사료급여 방법(P<0.01)에 의해 유의한 영향을 받아 가을에 분만한 구가 봄에 분만한 구에 비해 높은 결과를 보였으며 TMR 급여구가 조농분리 급여구 보다 높은 결과를 나타냈다. 산유량의 결과와 유사하게 비유후기인 9, 10개월차에 사료급여에 의해 통계적 유의차를 보여(P<0.01) TMR 급여구가 약 8% 높았으며, 7개월차(P=0.12)와 8개월차(P=0.09)에도 높은 경향을 나타내었다. 따라서 육성기에 TMR을 급여하고 가을에 분만할 경우 초산우의 산유량과 비유지속성 증진에 효과적일 것으로 사료된다. 평균 유지율은 사료급여의 영향을 받아 TMR 급여구가 조농분리 급여구 보다 7.8% 높았는데(P<0.01) 육성기 TMR 급여가 분만 후 섭취행동에 영향을 주어 반추위의 안정화로 인해 유지율이 증가한 것으로 사료된다. 분만 후 3개월차에는 봄에 분만한 구가 가을에 분만한 구보다 유지방 함량이 낮았으며(P<0.05) 이는 계절적 차이에 의한 것으로 사료된다. MUN은 평균과 4, 5 및 6개월차에 조농분리 급여구에서 유의하게 높았다(4개월차 P<0.01; 5, 6개월차 P<0.05). 체세포수는 평균과 분만 후 3, 4개월차에 TMR 급여구가 조농분리 급여구 보다 높은 결과를 보였다(P<0.01). 결과를 종합해보면, 육성기에 TMR 급여방법을 적용하고 가을에 분만하는 경우 봄에 분만하는 경우에 비해 여름철 고온의 영향을 비교적 덜 받아 산유량과 비유지속성 뿐만 아니라 유지율 등이 개선되어 경제성이 향상되는 효과를 보았다. 그러나 본 실험은 봄과 가을의 분만계절이 미치는 영향만을 보았기 때문에 여름과 겨울의 분만계절의 영향에 대한 추가 실험이 필요할 것으로 사료된다.

• Molecules and Cells
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• 제39권4호
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• pp.310-315
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• 2016

Coumarin is a phenolic compound that mainly affects the liver due to its metabolization into a toxic compound. The deterrent and ovicidal activities of coumarin in insect models such as Drosophila melanogaster have been reported. Here we explore the molecular mechanisms by which these insects protect themselves and their eggs from this toxic plant metabolite. Coumarin was fatal to the flies in a dosage-dependent manner. However, coumarin feeding could be inhibited through activation of the aversive gustatory receptor neurons (GRNs), but not the olfactory receptor neurons. Furthermore, three gustatory receptors, GR33a, GR66a, and GR93a, functioned together in coumarin detection by the proboscis. However, GR33a, but not GR66a and GR93a, was required to avoid coumarin during oviposition, with a choice of the same substrates provided as in binary food choice assay. Taken together, these findings suggest that anti-feeding activity and oviposition to avoid coumarin occur via separate mechanisms.

• Fisheries and Aquatic Sciences
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• 제24권12호
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• pp.415-427
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• 2021

Wetland ecosystems act as natural freshwater purification systems, but their rich biodiversity is being threatened with the introduction of the non-native freshwater snail, Pomacea canaliculata. This study was conducted to measure the herbivory effects and growth rate of P. canaliculata on common macrophytes: Ipomoea aquatica, Ipomoea batatas, Pandanus amaryllifolius and Cucurma longa. In separate experiments, the macrophyte species were served as the snails' food as individual species and simultaneously. In the individual treatment, the growth pattern and rate were based on the snails' weight (mg/snail/day; n = 9) while the individual feeding consumption (mg/snail/day) was calculated from the leftover food. In the simultaneous treatment, the herbivory effects were evaluated as the feeding preference (%) from observations every two hours, while the total feeding consumption (mg) was calculated based on the food remaining after a 12-hour experiment (3 replicates: total n = 27). The results indicated that the growth pattern was significant for snails grazing on I. aquatica but not when other macrophyte species were eaten. The individual feeding consumption was higher when using I. aquatica than P. amaryllifolius but the growth rate for snails grazing on I. aquatica and P. amaryllifolius did not differ significantly. Meanwhile, the consumption of C. longa deterred the snails' growth rate. Although the snails consumed all the macrophytes in the individual experiment, when given the species simultaneously, the feeding preference and total feeding consumption were directed significantly more toward I. aquatica than P. amaryfollius and C. longa. We conclude that P. canaliculata is a generalist feeder given a limited choice of food but tends to show a strong feeding preference after being introduced to more food choices. These findings indicate that the introduction of P. canaliculata into wetland ecosystems may increase the herbivory effects on macrophytes, making these ecosystems vulnerable to the impact of eutrophication and biodiversity reduction.

• Journal of Ecology and Environment
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• 제30권4호
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• pp.357-361
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• 2007

To determine the feeding sites preferred by adult gold-spotted pond frogs, Rana plancyi chosenica, and the foods that induce favorable growth of the frogs in the laboratory, we conducted two separate experiments between 27 May and 12 July 2007 in a vivarium. In the first experiment, we counted the number of crickets eaten by four gold-spotted pond frogs in a 60 min period at four different feeding sites within the experimental arenas: on the water surface, at the edge of a pond, and at two terrestrial sites. Adult gold-spotted pond frogs ate more crickets on the water surface and at the edge of the pond than the terrestrial sites. In the second experiment, we measured the growth of SVL (snout-vent length) and body mass of adult gold-spotted pond frogs fed crickets, mealworms, maggots, or earthworms in individual experimental boxes over a one month period. The SVL and body mass of the adult gold-spotted pond frogs fed crickets, mealworms, or maggots were greater than those of the frogs that were fed earthworms. These results indicate that providing crickets, mealworms, or maggots on the water or at the edge of a pond should induce favorable growth of captive-reared adult gold-spotted pond frogs.

• Asian-Australasian Journal of Animal Sciences
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• 제13권10호
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• pp.1461-1466
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• 2000

The use of the dairy male calf for beef production has been found to be economically unprofitable during the past due to high cost of feeds and relatively low beef price. However, due to current shortage of domestic beef supply and rising beef price, this research aimed to assess feeding methods and costs and returns in raising dairy male calves for beef production under changing economic conditions. Two diets were compared: calves on an optimal feeding level were given milk replacer for 44 d and a concentrate (with ad lib. hay) to 150 kg bodyweight that contained 16% crude protein; those given a sub-optimal diet, more appropriate for smallholder farms, received milk replacer for 30 d and 14% CP concentrate. Twelve pairs of dairy male calves (average age 32 days) of Holstein-Friesian high grades were used, each pair having similar influencing factors such as weight, age, and genotype. Each animal was kept in a separate feeding stall until reaching the final weight of 150 kg. The results from this experiment showed that the differences of traits concerning growth performance and feed efficiency of the animals raised under the two feeding regimes were statistically nonsignificant. The optimal group was just slightly better, but the cost of production of the sub-optimal group was 24 percent lower (4,667 vs. 6,144 baht per animal) and the cost difference was highly significant. The results from this investigation showed that beef production from dairy male calves can be economically viable when sub-optimal feeding method is used and market beef price is at current level.