• 농업과학연구
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• 제8권1호
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• pp.3-10
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• 1981

수도개체군(手稻個體群)의 생장(生長)과 수량(收量)을 생산생태자적관점(生産生態字的觀点)에서 해석(解析)하고저 그 생산구조(生産構造)와 평균생장속도(平均生長速度) 및 관련요인(關聯要因)의 영향(影響)을 구명(究明)하여 다음과 같은 결과(結果)를 얻었다. 1. 개체군하(個體群下)에서는 개체상태(個體狀態)보다 전생육기간(全生育期間)에 걸쳐 높은 평균생장속도(平均生長速度)를 지속(持續)하였으며 등숙기간(登熟期間)의 생장속도(生長速度)가 비교적(比較的) 높아 수량(收量)이 증가(增加) 하였다. 2. 벼의 개체군(個體群)이 평균생장속도(平均生長速度)를 높게 유지(維持)하였음은 순동화율(純同化率)보다 엽면적증대(葉面積增大)의 영향(影響)이 더 컸었다. 3. 개체군(個體群)서 품종(品種)에 따라서는 상위엽층(上位葉層)의 과번무(過繁茂)로 하위층엽(下位層葉)에 대(對)한 투광(透光)를 저해(沮害)하여 그 고사(枯死)를 많게 하였다. 4. 개체군(個體群)에서는 생육후기(生育後期)에 갈수록 동화기관(同化器官) 대(對) 비동화기관(非同化器官)의 비율(比率), 투광율(透光率) 및 엽신(葉身)의 질소함량(窒素含量)이 상대적(相對的)으로 저하(低下)하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권4호
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• pp.486-495
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• 2012

Twenty four periparturient cows were used to determine the effects of DCAD on acid-base balance, plasma and urine mineral concentrations, health status, and subsequent lactation performance. Each group of 12 cows received either a diet containing -100 DCAD or +100 DCAD for 21 d prepartum. Both anionic and cationic groups were divided into two groups, one received a +200 DCAD and the other +400 DCAD diet for 60 d postpartum. Prepartum reduction of DCAD decreased DMI, urinary and blood pH, urinary concentrations of Na or K and increased plasma and urinary Ca, Mg, Cl and S. Also cows fed -100 DCAD diet consumed the most dry matter in the first 60 d after calving. Postpartum +400 DCAD increased milk fat and total solid percentages, urinary and blood pH and urinary Na and K concentrations, but urinary Ca, P, Cl and S contents decreased. Greater DMI, FCM yields were observed in cows fed a diet of +400 DCAD than +200 DCAD. No case of milk fever occurred for any diets but feeding with a negative DCAD diet reduced placenta expulsion time. In conclusion, feeding negative DCAD in late gestation period and high DCAD in early lactation improves performance and productivity of dairy cows.

• Asian-Australasian Journal of Animal Sciences
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• 제28권5호
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• pp.703-715
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• 2015

One of the challenges to increase milk production in a large pasture-based herd with an automatic milking system (AMS) is to grow forages within a 1- km radius, as increases in walking distance increases milking interval and reduces yield. The main objective of this study was to explore sustainable forage option technologies that can supply high amount of grazeable forages for AMS herds using the Agricultural Production Systems Simulator (APSIM) model. Three different basic simulation scenarios (with irrigation) were carried out using forage crops (namely maize, soybean and sorghum) for the spring-summer period. Subsequent crops in the three scenarios were forage rape over-sown with ryegrass. Each individual simulation was run using actual climatic records for the period from 1900 to 2010. Simulated highest forage yields in maize, soybean and sorghum- (each followed by forage rape-ryegrass) based rotations were 28.2, 22.9, and 19.3 t dry matter/ha, respectively. The simulations suggested that the irrigation requirement could increase by up to 18%, 16%, and 17% respectively in those rotations in El-Nino years compared to neutral years. On the other hand, irrigation requirement could increase by up to 25%, 23%, and 32% in maize, soybean and sorghum based rotations in El-Nino years compared to La-Nina years. However, irrigation requirement could decrease by up to 8%, 7%, and 13% in maize, soybean and sorghum based rotations in La-Nina years compared to neutral years. The major implication of this study is that APSIM models have potentials in devising preferred forage options to maximise grazeable forage yield which may create the opportunity to grow more forage in small areas around the AMS which in turn will minimise walking distance and milking interval and thus increase milk production. Our analyses also suggest that simulation analysis may provide decision support during climatic uncertainty.

• Asian-Australasian Journal of Animal Sciences
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• 제14권12호
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• pp.1728-1733
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• 2001

An experiment was conducted at the experimental duck farm of Cantho University in the Mekong Delta of Vietnam to evaluate the effects of offering pairwise feeds with different crude protein (CP) levels to Cherry Valley broiler ducks from 28-63 days of age on feed intake and performance. Five diets consisting of mixtures of soya bean meal, fish meal, maize meal and fine rice bran, were formulated to give isocaloric diets with 30, 24, 18, 16 and 12% CP. These were offered separately as pellets to growing ducklings in the following combinations: 30+18, 30+12, 24+16 and 18+12. A diet with 20% CP (CP20) was used as control. All the diets were offered ad libitum. Daily feed intakes (g dry matter, DM) were 161, 168, 150, 101 and 143 g for the 30+18, 30+12, 24+16, 18+12 and CP20 treatments, respectively. CP intakes were 29.6, 27.0, 24.8, 17.1 and 22.9% of total DM intake, and the ratio of methionine+cystine to lysine was 0.76, 0.75, 0.75, 0.76 and 0.75 for the 30+18, 30+12, 24+16, 18+12 and CP20 treatments, respectively. Live weights at 63 days of age were 2,937, 3,054, 2,898, 2,200, and 2,811 g (p<0.001), and daily live weight gains 57.8, 61.7, 57.0, 38.5 and 55.7 g (p<0.001) for the 30+18, 30+12, 24+16, 18+12 and CP20 treatments, respectively. The weights and yields of the carcass, breast and thigh muscles, and heart decreased in the order 30+18, 30+12, 24+16, CP20 and 18+12 (p<0.001). The present study suggests that growing broiler offered a combination of high and low protein feeds pairwise will eat excessive amounts of the high protein feed, thus resulting in protein intakes above requirements.

• Asian-Australasian Journal of Animal Sciences
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• 제17권4호
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• pp.473-478
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• 2004

Processing and storage of the silage from agricultural by-products were studied in two experiments. The first experiment was conducted to investigate the chemical composition and degradability of various silages with varying ensiling times. The experiment was a 5$\times$3 factorial design, completely randomized, with factor A as the different formulated mixtures by varying level of urea addition (0, 0.5, 1.0, 1.5 and 2.0%) and factor B as the time of ensiling. Chemical composition changed little with time and varied only slightly with levels of urea in the mixtures. Dry matter (DM) degradability increased with increasing cassava levels while crude protein degradability and pH level increased with increasing urea addition. By using 'Flieg point', which relates to organic acid yields, there were no significant difference among ensiled mixtures and times of ensiling. Therefore it can be concluded that the 5th silage formulation is the most appropriate since its DM and crude protein (CP) degradability were highest. The second experiment was carried out to determine the quality of the 5th silage mixtures (from the previous trial) after being stored for up to 6 months. The experiment was a complete randomized design with samples taken at monthly intervals up to 6 months and subjected to laboratory and degradability analyses. The results showed no significant (p>0.05) difference in chemical composition except for increased neutral detergent fiber and acid detergent fiber percentage in association with increasing storage time. There were no significant (p>0.05) differences in 'Flieg point' among times of storage. In conclusion, this experiment showed that the silage from agricultural by-products can be stored for more than 6 months.

• Journal of Animal Science and Technology
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• 제60권5호
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• pp.12.1-12.5
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• 2018

Background: The use of agroindustrial by-products in ruminant nutrition to be an interesting alternative in order to reduce production costs and environmental impacts arising from the inadequate destination of residues. The initial step of beer production yields a large volume of wet brewer's grains all year around, which is available at a low cost and has a high nutritional quality, and hence a big potential for animal production. Methods: Twenty-four Suffolk non-castrated male lambs, from simple parturition were kept in individual spots and allocated to four treatments constituted by four levels of substitution of sorghum silage by WBG (i.e.0; 33.5; 66.5 and 100% of substitution). It was used roughage: concentrate rate of 50:50, based on dry matter. Results: The ether extract intake increased while the acid detergent fiber intake decreased linearly ($P{\leq}0.05$). Substituion of sorghum silage by WBG did not change lambs' feed DMI, daily weight gain and feed conversion. Conclusion: The substitution of sorghum silage by WBG as roughage showed to be a viable alternative from the productive and economic point of view for finishing of feedlot lambs.

• 한국초지조사료학회지
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• 제17권1호
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• pp.27-34
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• 1997

This experiment was carried out to determine growth characteristics, dry matter (DM) yield, seasonal yield distribution and nutritive value of early- and late maturity orchardgrass, 1990 to 1992. The cultivars used in this study were Potomac, Hallmark (early maturing cultivar) and Lidacta, Rancho (late maturing cultivar), and a mixture plot (Potomac 25% + Hallmark 25% + Lidacta 25% + Rancho 25%) was involved. The seeding rate was 20 kgha in all treatments. Plant height of Potomac and Hallmark was longer than that of Lidacta and Rancho. The dates of initial heading and 50% heading of early maturing cultivars (Apr. 30 and May 10) were 10 days earlier than those of late matuing cultivars. Potomac and Hallmark were upright, and Lidacta and Rancho were semi-upright type, and severe disease and weeds (30 ~ 40%) were observed at Lidacta plot. On an average of three years, the DM yields of Potomac (10,549 kglna), Hallmark (10,435 kg) and mixture (10,356 kg) were significantly (P<0.05) higher than those of Rancho (9,457 kg) and Lidacta (8,218 kg). However, seasonal yield distribution of late maturing cultivars was better than that of early maturing cultivars. The contents of crude protein, crude fat, crude fiber, nitrogen %ee extract, aude ash, neutral detergent fiber, P, K, Ca, and Mg were not significantly different between cultivars, but higher aude protein yield was found at Potomac, Hallmark and mixture plots. Based on the above results, it may be concluded that early maturing cultivars for high productivity, late maturing cultivars for seasonal yield distribution, and seeding of mixture andlor separation of early- and late maturing cultivars are recommended. Also Lidacta was a not promising cultivar due to low productivity, severe disease, and high weeds development.

• 한국초지조사료학회지
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• 제21권2호
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• pp.59-66
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• 2001

In order to determine the influence of nitrogen on agronomic characters, forage yield and quality, a Kenaf was cultured on the volcanic ash soil at the Experimental Farm of Cheju national University under the seven levels of nitrogen rates(0, 50, 100, 150, 200, 250kg/ha) from April 25 to Dec. 25, 1999. The plant height increased by increase of nitrogen rate, showing longest 250kg/ha with 286.6cm and shortest at no application plot with 255.7cm. The difference on leaf number, leaf withering number, stem diameter and branches number by nitrogen rate showed a similar tendency to the plant height. Increasing N rate from 0 to 250kg/ha fresh forage yield form 55.8 to 99.8MT/ha, dry matter (DM) yield from 8.8 to 15.8MT/ha, crude protein(CP) yield form 1.2 to 3.1MT/ha, total digestible nutrients (TDN) yield from 3.8 to 8.6MT/ha. However, no significant differences in these yields were found between 200 and 250kg N/ha. Nitrogen uptake increased form 192.9 to 496.2 kg/ha but N use efficiency decreased form 95.0 to 66.6 kg DM$^{a}$ /kg N with increasing from 0 to 250 kg/ha. As N rate increased from 0 to 250kg/ha, leaf and stem out of CP, crude fat (CF), nitrogen free extract (NFE), TDN contents increased from 20.1% to 25.8% and from 9.7% to 12.4%, from 5.6% to 8.1% and from 3.3% to 4.4%, from 36.1% to 40.2% and from 21.9% to 32.4%, from 59.3% to 75.0% and from 32.2% to 38.2%, respectively, while leaf and stem out of crude fiber decreased from 18.5% to 16.7% and from 51.5% to 39.3%. Based on the these findings, the optimum N rate for forage production of kenaf seems to be about 200 kg/ha in atmospheric phenomena and volcanic ash soils of jeju island.

• 한국초지조사료학회지
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• 제9권1호
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• pp.56-61
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• 1989

本 연구는 濟州道內 放救用 野草地(마을共同收場)에서 野草類의 植生 및 收量性을 조사하여 草地改良 및 野草地의 利用度 增進을 위한 基鍵資料로 活用코자 放牧期間인 7 月부터 9 月까지 수행되었으며 quadrat method를 利用하여 조사한 結果는 다음과 같다. 1. 野草의 總草種은 64種으로 未本科 13草種, 두과 8草種, 엉거시科 12草種, 그리고 기타 31草 종으로 대부분 多年生 草類였다. 2.. 식생적性率은 띠 (Imperata cylindrica) 32.7%, 고사리 (Pteridium aquilinum) 18.9%, 억새 (Miscanthus sinensis) 8.4% 順이었고, 科別로는 未本科草種이 47.5%를 차지하였다. 3. 野草地의 l0a當 乾物收量은 7月이 160kg, 8月이 200-400kg, 9月 이 400-1,000kg으로 평균收量은 383 kg였으며, 生草收量은 평균 1,030kg으로 生育이 進行되면서 점차 증가하였다.

• Journal of Animal Science and Technology
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• 제56권2호
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• pp.5.1-5.5
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• 2014

The objectives of this study were thus to identify most significant factors that determine milk component yield (MCY) using a meta-analysis and, if possible, to develop equations to predict MCY using variables that can be easily measured in the field. A literature database was constructed based on the research articles published in the Journal of Dairy Science from Oct., 2007 till May, 2010. The database consisted of a total of 442 observed means for MCY from 118 studies. The candidate factors that determine MCY were those which can be routinely measured in the field (e.g. DMI, BW, dietary forage content, chemical composition of diets). Using a simple linear regression, the best equations for predicting milk fat yield(MFY) and milk protein yield (MPY) were $MFY=0.351({\pm}0.068)+0.038({\pm}0.003)$ DMI ($R^2=0.27$), and $MPY=0.552({\pm}0.071)+0.031({\pm}0.002)DMI-0.004({\pm}0.001)$ FpDM (%, forage as a percentage of dietary DM) ($R^2=0.38$), respectively. The best equation for predicting milk fat content (%) explained only 12% of variations in milk fat content, and none of a single variable can explain more than 5% of variations in milk protein content. We concluded that among the tested variables, DMI was the only significant factor that affects MFY and both DMI and FpDM significantly affect MPY. However, predictability of linear equations was relatively low. Further studies are needed to identify other variables that can predict milk component yield more accurately.