• Asian-Australasian Journal of Animal Sciences
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• 제14권10호
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• pp.1383-1388
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• 2001

To explore the factors restricting animal performance in relation to sward structure under a strip-grazing system, measurements of sward factors, herbage intake and milk production at 3 levels of herbage allowance were made on perennial ryegrass (Latium perenne L.) sward for 3 experimental periods. About 29%, 36% and 52% of the biomass offered was removed by grazing in high $(42kg\;OM{\cdot}day^{-1}{\cdot}head^{-1})$, medium $(30kg\;OM{\cdot}day^{-1}{\cdot}head^{-1})$ and low $(18kg\;OM{\cdot}day^{-1}{\cdot}head^{-1})$ herbage allowance plots. Live leaf material was much more affected by grazing under different herbage allowance levels than dead material or leaf sheath. Grazing with a low herbage allowance decreased the proportion of live lamina by 93% and live lamina density by 96% before grazing. The density of dead material plus sheath was decreased by 17% after grazing at a low allowance, while it slightly increased or remained constant in the plots applied with high and medium allowances, respectively. The highly significant (p<0.01) correlations between herbage allowance and proportion (r=0.94) and density (r=0.91) of live lamina in residual sward after grazing were observed. Daily herbage intakes in the plots with high and medium levels of herbage allowance were not significantly different at $15.3kg\;OM{\cdot}head^{-1}$ in average, whereas with low level it decreased to $13.9kg\;OM{\cdot}head^{-1}$. Daily milk production was significantly (p<0.05) declined from $22.3kg{\cdot}head^{-1}$ (at high herbage allowance) to $19.7kg{\cdot}head^{-1}$ (at low herbage allowance). The data obtained clearly indicated that herbage intake and milk production were highly affected by the characteristics of residual sward, which were closely related to the level of herbage allowance.

• Asian-Australasian Journal of Animal Sciences
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• 제9권5호
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• pp.577-582
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• 1996

In order to investigate the relationship between daily herbage allowance (DHA) and daily herbage intake (DHI) on the points of leaf and stem masses, grazing experiments were carried out on the pasture of tall fescue (Festuca arundinacea Schreb.). The experiments consisted of four 3-days' grazing periods which were from August 14 to 17, August 17 to 20, October 12 to 15 and October 15 to 18 in 1990. The value of DHA was 32.1 to 84.3, and the value of DHI was 9.9 to 27.0. The index of leafiness (leaf to stem ratio, LSR) was 0.74 to 3.06. The relationship between DHI and DHA was quadratic. Both relationship of daily leaf intake (DLI) to daily leaf allowance (DLA) and that of daily stem intake (DSI) to daily stem allowance (DSA) were likely to be asymptotic forms, although DHI did not show any significant relationships to DLA nor to DSA. The relationship between DLI and LSR was quadratic, and a negative relationship was found between DSI and LSR. From the relationship of DLI to LSR and that of DSI to LSR, the relationship of daily intake of leaf and stem (DLSI) to LSR was derived as quadratic and the LSR value at which the maximum DLSI was attained was estimated. The DHA, DHI, DLA, DLI, DSA, DSI and DLAI were expressed as the same unit of g/kg live body weight/day.

• 한국초지조사료학회지
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• 제14권2호
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• pp.110-119
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• 1994

대상방목 체계하에서 Lolium perenne초생의 채식 허용량을 3 수준으로 달리 하여 고능력 착유우에 의한 방목시험으로부터 얻은 채식량과 산유량을 조사하여 얻을 결과를 요약하면 아래와 같다. 채식된 사포로부터 배설된 분증질소, 크롬 및 회분 함량은 시험시기가 늦을수록, 채식허용량이 낮을수록 약간 감소되는 경향이었다. 시험시기별 채식 허용량의 수준에 따른 채식초의 소화율은 시험시기 1의 82.7%에서 시험시기 3의 79.1%로 감소하였고, 고수준의 채식허용량일 때 81.6%에서 저수준일 때 79.9%로 감소하였다. 일당 채식량은 고와 중 수준의 채식허용량에서 15.8과15.9kg OM/cow로 비슷한 수준이었으나 저수준에서는 14.6 kg OM/cow로 유의적으로 감소하였다. 시험시기별 채식량은 시험시기가 늦을수록 감소하는 경향이었으나 유의적인 차이는 없었다. 일당 4%유지방 보정 산유량은 시험시기 1의 23.6kg OM/cow에서 시험시기 3에서는 20.6kg OM/cow로 유의적으로 감소하였으며, 채식허용량의 수준에 따른 일당 산유량은 고와 중 수준일 때 각각 23.5와 22.2kg OM/cow로 유의적으로 감소하였다. 채식허용량의 수준과 채식량(r=0.88)및 산유량(r=0.81)간에 고도(p<0.01)의 정의 상관관계가 인정되었다.

• 한국초지조사료학회지
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• 제14권2호
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• pp.99-109
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• 1994

방목체계하에서 일당 채식허용량(kg OM/cow)의 수준에 따른 일당 채식량 및 산유량의 경향을 방목에 따른 초생의 구성 및 구조적 변화와 관련하여 검토하는데 목적을 두었다. 본 보에서는 5일간 24시간 대상 방목체계하에서 고능력 착유우에 대한 3 수준의 일당 채식허용량에서 방목후 초생의 구조와 관련된 요인들의 변화를 조사한 결과를 요약하였다. 시험시기별 방목적 초생량 및 초장은 시험시기 1에서 5,047kg OM/ha와 341mm에서 초생의 생육이 진행됨에 따라 유의적으로 증가하여 시험시기 3에서 6,877kg OM/ha와 446mmduTdmsk, 채식허용량의 수준을 달리한 시험구 간에는 유의적인 차이가 없없다(평균 6,068kg OM/ha와 410mm). 방목후 초생의 구성은 채식허용량의 수준에 의해 많은 영향을 받았는데, 방목후 초생내 청엽의 수직적 분포높이, 비율 및 밀도는 고사엽과 엽초보다 훨씬 높은 감소비율을 보였고, 방목전 청엽은 지상 50cm까지 분포되어다가 방목후 고 및 중 수준이 채식허용량에서는 25cm까지, 저 수준의 채식허용량에서는 20cm까지 분포되어 있던 청엽은 모두 채식되었다. 방목깊이와 예취된 채식초의 부피는 채식허용량의 수준에 따라 유의적인 영향을 받았다. 방목후 초생량은 방목전 수준에 비해 고, 중 및 저 수준의 채식허용량에서 방목전 수준에 비래 각각 35, 36 및 52%가 감소되었다. 채식허용량과 방목후 초장(r=0.79), 생엽의 비율(r=0.94) 및 생엽의 밀도(r=0.91)간에 각각 고도의 정의 상관관계가 인정되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제12권2호
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• pp.209-214
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• 1999

Grazing preference, voluntary dry matter intake, stocking rate and digestibility of forage were investigated or sheep grazed in mature oil palm plantations in Malaysia. Dry matter intake (DMI) was estimated using the chromium sesquioxide marker method. The sheep were allowed to graze about 5 hours/day in oil palm plantations of age ranging from 9 to 21 years old. The crude protein, crude fibre and ash contents of selected herbage were 13.1 %; 24.6 %; and 8.3 %, respectively, while the gross energy (GE) and the metabolisable energy (ME) were 16.9 and 6.0 MJ/kg DM, respectively. Broad leaf plants and grasses were normally found in plantation of all ages. Legumes and oil palm seedlings formed the smallest group in the whole mixture. Fern content increased in older plantations. Legumes, oil palm seedlings, fern, broad leaves and grasses were 0.4, 1.3, 11.4, 28.0 and 59.0 %, respectively of total herbage. Grasses showed the highest preference index followed by broad leaf plants, legumes, oil palm seedlings and ferns in that order. The DMI and the metabolisable energy intake (MEI) of sheep at 6, 8, 10, 12 and 14 months of age were 64.8, 65.0, 65.3, 65.6 and 67.4 g/kg $W^{0.75}$ (p<0.05) and 0.39, 0.40, 0.40, 0.40 and 0.41 MJ/kg $W^{0.75}$, respectively. The average stocking rate was 4.3 sheep/ha. It was concluded that the performance of the sheep could be improved by increasing the daily grazing period and also by appropriate concentrate supplementation.

• 한국초지조사료학회지
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• 제17권3호
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• pp.265-276
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• 1997

This study was investigated the herbage productivity and nutrient contents of corn (Suweon 19 and Kwanganok) and sweet sorghum (Ramiki sorgo and Silage sorgo) at the stage of maturity (10-DBS, silking, milky and dough stages) to identify the utility value of sweet sorghum as a substituting crop for corn. The silage materials (dough stage) were chopped and were storaged for 90 days in polyethlene bag with O.lmm thickness. Chemical composition, nitrogen content and in vitm dry matter digestibility were evaluated. Also, daily intake and palatability were checked in the feeding trial with four male sheep in average weight about 57kg. Both fresh and dry matter yield of corn and sweet sorghum were increased as the maturity processed (P< 0.05), and sweet sorghum showed higher total yield potential than corn. Crude protein content of the cultivars was decreased as the maturity was processed (P< 0.05). Neutral detergent fiber (NDF) content of the cultivars, in general, showed highest at silking stage, followed by 10 days before silking (10-DBS), and milky and dough stages (Pi0.05) in order. Acid detergent fiber (ADF) content was increased as the maturity processed, and it showed the highest value at milk stage. However, the contents of ADF in sorghum plant was decreased during the late maturity. Crude protein content of the silage was not significantly different among cultivars used, while NDF content was highest in Ramiki sorgo, followed by Silage sorgo, Kwanganok and Suweon 19. In v i m DM digestibility of the silage was highest in Kwanganok, followed by Suweon 19, Silage sorgo and Ramiki sorgo. Total N content of the silage was highest in Ramiki sorgo, followed by Suweon 19, Silage sorgo and Kwanganok. DM intake of the silage was highest in Ramiki sorgo, followed by Suweon 19, Silage sorgo and Kwanganok and it was closely related to the palatability value.

• Asian-Australasian Journal of Animal Sciences
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• 제24권6호
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• pp.766-773
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• 2011

The objective of the present study was to examine whether yaks possess any adaptive mechanisms of nitrogen (N) metabolism to survive in the harsh foraging environment of the Qinghai-Tibetan Plateau. A grazing experiment on native alpine meadows was conducted to determine availability of herbage biomass and body weight (BW) change of yaks over the year, followed by two indoor feeding trials to investigate adaptation mechanisms of N metabolism in yaks fed at similar intake level to grazing conditions. Three castrated males of each of three genotypes; yak (Bos grunniens), indigenous cattle (Bos taurus) and their crossbred - cattleyak (Bos taurus male${\times}$Bos grunniens female), were used in the housed trials. Results showed that: i) Monthly herbage biomass production and daily grazing intakes by yaks over the year ranged from 220 to 4,664 kg DM per ha, and 1.90 to 8.50 kg DM, respectively. For about seven months each year, yaks suffer from malnutrition as a result of inadequate pasture conditions; ii) Urinary N excretion and N retention by yaks were significantly affected by feeding level, and yaks had a lower (p<0.05) average daily urinary N excretion (0.39 g/kg $BW^{0.75}$) and a greater (p<0.05) N retention (-0.09 g/kg $BW^{0.75}$) than indigenous cattle (0.47 and -0.16 g/kg $BW^{0.75}$, respectively). Fasting daily urinary N excretion was greater (p<0.05) for indigenous cattle than yaks (353 vs. 248 mg/kg $BW^{0.75}$). Purine derivative N excretion and purine derivative N index (PNI) increased with increasing feeding level, while the value of PNI was greater (p<0.05) for yaks and cattleyak (0.11 and 0.12, respectively) than for indigenous cattle (0.09) during the feeding trials. These results suggest that yaks could rely, in part, on the recycling of N to adapt to the harsh forage environment on the Qinghai-Tibetan Plateau.), were used in the housed trials. Results showed that: i) Monthly herbage biomass production and daily grazing intakes by yaks over the year ranged from 220 to 4,664 kg DM per ha, and 1.90 to 8.50 kg DM, respectively. For about seven months each year, yaks suffer from malnutrition as a result of inadequate pasture conditions; ii) Urinary N excretion and N retention by yaks were significantly affected by feeding level, and yaks had a lower (p<0.05) average daily urinary N excretion (0.39 g/kg $BW^{0.75}$) and a greater (p<0.05) N retention (-0.09 g/kg $BW^{0.75}$) than indigenous cattle (0.47 and -0.16 g/kg $BW^{0.75}$, respectively). Fasting daily urinary N excretion was greater (p<0.05) for indigenous cattle than yaks (353 vs. 248 mg/kg $BW^{0.75}$). Purine derivative N excretion and purine derivative N index (PNI) increased with increasing feeding level, while the value of PNI was greater (p<0.05) for yaks and cattleyak (0.11 and 0.12, respectively) than for indigenous cattle (0.09) during the feeding trials. These results suggest that yaks could rely, in part, on the recycling of N to adapt to the harsh forage environment on the Qinghai-Tibetan Plateau.

• 한국초지조사료학회지
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• 제16권2호
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• pp.127-132
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• 1996

This study was carried out to obtain good livestock production in comparison with 3 different pasture mixture (Control : TI = Potomac orchardgrass + Bastion perennial ryegrass + Fawn tall fescue + Regal white clover, T2 = Potomac orchardgrass + Bastion perennial ryegrass + Roa tall fescue + Regal white clover, T3 = Potomac orchardgrass + Bastion perennial ryegrass + Roa tall fescue + Tahora white clover) by grazing experiment used 45 dairy calves (about lOOkg liveweight) during the period from April to October, 1994 at the Isidole farm, Cheju. Daily liveweight gains of calves grazed during the experiment period were 331${\pm}$29, 352${\pm}$4, 356${\pm}$18g in treatment 1, 2 and 3 respectively, but did not get statistically significant difference. On compared the results with the period investigated, the period which was highest in daily liveweight gain was early grazing season b m May to June while the period shown to be lowest in daily liveweight gain was between late July and late August. Hehage intake rate did not get significant difference among treatments with results shown as 67${\pm}$1.2, 62${\pm}$5.1, 60${\pm}$9.6% in treatment 1, 2 and 3 respectively. And efficiency of conversation into animal product was high in treatment 2. It is considered that good results were not obtained in this study because tall fescue and white clover, important species in this trial did not cover the pasture well with slow establishment in 1st year after seeding.

• Asian-Australasian Journal of Animal Sciences
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• 제18권11호
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• pp.1564-1568
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• 2005

The objective of the study was to evaluate the use of n-alkanes to estimate DM intake and digestibility by beef cattle. Six steers were blocked (3 blocks, 2 animals/block) according to the body weight (279${\pm}$19 kg) and randomly allotted within blocks to two diets (3 steers/diet). A second trial was conducted with the same animals (321${\pm}$18 kg) after 36 days (d), using a switch back design. The diets consisted of two types of chopped sun-cured hay, alfalfa (Medicago sativa L) hay, or fescue (Festuca arundinacea Schreb) and alfalfa mixture, which were fed in equal amounts to steers. Animals were dosed with $C_{32}$ and $C_{36}$ alkanes, employing an intra-ruminal controlled-release device at the beginning of each trial. Hay intake per animal was measured from d 6 to 12 and sub samples were taken for chemical analysis. Rectal samples of feces were taken from each animal once/daily from d 8 to 14, freeze dried, and ground prior to alkane analysis. Alkanes were extracted from ground hay and feces. Feed intake was calculated from the dose rate of $C_{32}$ alkane and, the herbage and fecal concentrations of adjacent odd ($C_{33}$ or $C_{31}$) and even ($C_{32}$) chain length alkanes. Crude Protein, NDF, ADF, ash concentrations and In vitro dry matter digestibility (IVDMD) were 17.7, 42.2, 28.4, 7.9 and 71.7 for alfalfa, and 12.4, 56.5, 30.4, 6.9 and 69.1% for fescue/alfalfa mixture, respectively. For both diets, intake estimated from $C_{33}$:$C_{32}$ ratio was not different from the measured intake, but intake estimated from $C_{31}$:$C_{32}$ ratio was lower (p<0.05), than the measured intake for both diets. The average estimated forage intake from $C_{33}$:$C_{32}$ ratio was 4.86 and 0.69% below than the measured intake for alfalfa and, fescue/alfalfa mixed diets, respectively. The respective estimates with $C_{31}$:$C_{32}$ ratio were 9.59 and 11.33% below than the measured intake. According to these results, alkane $C_{33}$:$C_{32}$ ratio is better than alkane $C_{31}$:$C_{32}$ ratio for the estimation of intake by beef steers.

• 한국초지조사료학회지
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• 제29권4호
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• pp.383-388
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• 2009

본 연구는 혼파초지에서 유 산양을 방목 이용하였을 때의 건물섭취량, 증체량 및 두당 방목초지의 소요면적을 산출하고자 2007년 4월부터 2008년 6월까지 충남대학교 동물사육장내 혼파초지에서 수행하였다. 공시초지는 2006년 9월 21일 orchardgrass (40%) + tall fescue (20%) + perennial ryegrass (10%) + alfalfa (15%) + red clover (15%)를 ha당 30 kg 파종하여 경운초지로 조성한 혼파초지에서 수행하였다. 방목면적은 총 $5,000\;m^2$로 4목구(구당 평균 $1,250\;m^2$)의 윤환 방목으로 12회 방목하였다. 공시축은 Saanen종으로 13두(평균 31.1 kg)를 방목하였다. 방목기간 중 월 별로 조사한 혼파초지의 평균 조단백질 함량은 20.4%, NDF와 ADF 함량은 각각 65.3%와 31.1%이었으며, 건물소화율은 68.9%이었다. 두당 평균 건물섭취량은 1.253 kg 이었으며, 체중 당 3.01%을 섭취하였다. 방목기간 (184일)의 두당 평균 증체량은 17.4 kg이었고, 일당증체량은 98g이었다. 유 산양(체중 50 kg 기준)의 두당 방목초지의 소요면적은 $467.7\;m^2$로 산출되었는데 이를 Animal unit (AU/ha)로 환산하면 약 2.14 AU/ha에 해당하였다.