• Asian-Australasian Journal of Animal Sciences
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• v.14 no.10
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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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• v.9 no.5
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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.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.2
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• pp.110-119
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• 1994

Measurements of hehage intake and milk yield were made on high yielding dairy cows, which were strip-grazed on Loliurn perenne sward at three levels of herbage allowance in three experimental periods. The contents of nitrogen, chrome and ash in the faeces slightly decreased with the progress of growth period of experimental sward, and the decrease of herbage allowance. There were small difference in herbage digestibility among periods or the levels of herbage allowance with falling from 82.7% to 79.1% from period 1 to period 3 and from 81.6% to79.9% from high to low level of herbage allowance. Daily herbage intake was 15.8 and 15.9 kg OMIcow at the high and medium levels of hecbage aljowance, but reduced significantly to 14.6 kg OM/cow at the low level. Herbage intakes in three periods were shown a slight decrease. Daily milk yield in terms of 4% FCM significantly decreased from 23.6 to 20.6 kg/cow from period 1 to period 3. Milk yield at the high and medium levels of herbage allowance were 23.5 and 22.2 kg/cow at the low level of herbage allowance. The highly significant (P<0.01) correlations between the level of herbage allowance and herbage intake (r=0.88), or milk yield (r=0.81) were obtained.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.2
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• pp.99-109
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• 1994

The objective of this study was to examin some animal and sward factors which determine the daily herbage intake of high yielding dairy cows at different levels of daily herbage allowance. In this paper, the principal data relevent to the changes of sward characteristics after five days of daily strip grazing at three experimental peliods were summarized. The pregrazing herbage mass and extended height increased significantly from 5,047 kg OM/ha and 341 mm in period 1 to 6,877 kg OM/ha and 446 mm in period 3, while there was not a significant difference among herbage allowance treatments(average 6,068 kg OM/ha and 410 mm). The live leaf material in the residual herbage showed a greater reduction than the dead material and leaf sheath in terms of extended height, proportion and density. The decreased rates after grazing were higher when the level of herbage allowance decreased. Live leaves were vertically distributed to 50 cm of sward height before grazing. All live lamina distributed to 25 cm were grazed in the high and medium, and to 20 cm in the low levle of herbage allowance after grazing. The depth of grazing and grazed volume of forage material were heighly affected by the levels of hehage allowance. The biomass after grazing in the high, medium and low daily herbage allowance decreased 35, 36 and 52%, respectively, compared to before grazing level. The highly significant correlations between herbage allowance and extended tiller height(r=0.79), proportion of live lamina(r=0.94) and density of live lamina(r=O.91) after grazing, respectively, were observed.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.2
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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.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.3
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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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• v.24 no.6
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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.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.2
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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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• v.18 no.11
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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.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.4
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• pp.383-388
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• 2009

This study was conducted to investigate the dry matter intake, weight gain and the required area of grazing pasture for dairy goats. The experimental trials were conducted from April, 2007 to June, 2008 at the animal experimental station in Chungnam National University. The seed mixtures of grazing pasture were composed of orchardgrass (40%) + tall fescue (20%) + perennial ryegrass (10%) + alfalfa (15%) + red clover (15%). The grazing area was $5,000\;m^2$ which was composed of 4 paddocks (average $1,250\;m^2$/plot) and the goats were grazed twelve times by a rotational grazing system. The dairy goats (Saanen) were selected which had nearly the same body weight (average 31.1kg). The average chemical composition of herbage of mixture in grazing periods was crude protein (20.4%), NDF (65.3%) and ADF (31.1%) respectively and the in vitro dry matter digestibility was 68.9%. The average dry matter intake amount per head was 1.253 kg, and the intake amount per body weight was 3.01%. The average body weight gain during the grazing periods (184 days) was 17.4 kg, and the daily gain was 98 g. The required area of grazing pasture was calculated at $467.7\;m^2$ a dairy goat (weight 50 kg basis). This figure, being converted into animal unit (AU), corresponded to approximately 2.14 AU/ha.