• Animal Bioscience
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• v.34 no.10
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• pp.1623-1631
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• 2021

Objective: This study aimed to validate and evaluate the dry matter (DM) intake prediction model of the Korean feeding standards for dairy cattle (KFSD). Methods: The KFSD DM intake (DMI) model was developed using a database containing the data from the Journal of Dairy Science from 2006 to 2011 (1,065 observations 287 studies). The development (458 observations from 103 studies) and evaluation databases (168 observations from 74 studies) were constructed from the database. The body weight (kg; BW), metabolic BW (BW^0.75, MBW), 4% fat-corrected milk (FCM), forage as a percentage of dietary DM, and the dietary content of nutrients (% DM) were chosen as possible explanatory variables. A random coefficient model with the study as a random variable and a linear model without the random effect was used to select model variables and estimate parameters, respectively, during the model development. The best-fit equation was compared to published equations, and sensitivity analysis of the prediction equation was conducted. The KFSD model was also evaluated using in vivo feeding trial data. Results: The KFSD DMI equation is 4.103 (±2.994)+0.112 (±0.022)×MBW+0.284 (±0.020)×FCM-0.119 (±0.028)×neutral detergent fiber (NDF), explaining 47% of the variation in the evaluation dataset with no mean nor slope bias (p>0.05). The root mean square prediction error was 2.70 kg/d, best among the tested equations. The sensitivity analysis showed that the model is the most sensitive to FCM, followed by MBW and NDF. With the in vivo data, the KFSD equation showed slightly higher precision (R² = 0.39) than the NRC equation (R² = 0.37), with a mean bias of 1.19 kg and no slope bias (p>0.05). Conclusion: The KFSD DMI model is suitable for predicting the DMI of lactating dairy cows in practical situations in Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.5
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• pp.735-741
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• 1999

The effects of supplementation with nitrogen molasses mineral blocks and molasses urea mix during and immediately prior to the dry season on the production of dairy cows were studied on-station and on-farm near Morogoro, Tanzania. Supplementation of blocks to on-station cows also receiving ad libitum grass hay and 6 kg/d of maize bran increased milk production from 6.7 L/d to 11.2 L/d (p<0.05), increased dry matter intake from 10.1 kg/d to 12.0 kg/d (p<0.05), but did not significantly affect milk composition, intake of hay, and live weight changes. This increase in milk yield is mainly explained by increased intakes of energy and nitrogen. Supplementation with the molasses urea mix increased daily milk yield from 6.7 L/d to 8.8 L/d (p<0.05), but did not significantly affect the other measured production parameters. The on-farm supplementation of the blocks increased daily milk yield by 1.5 L/d in the dry season (p<0.05). This supplementation did not increase milk yields prior to the dry season, since quality forage was still available. Taking the production costs into account, supplementation with the blocks and supplementation with mix were cost effective if milk yields increased by 0.7 L/d. Hence supplementation with blocks and supplementation with mix were effective on-station, and supplementation with blocks was cost effective on-farm during the dry season.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.1
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• pp.61-68
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• 1998

This research was canied out to investigate the effect of castration and injection time of sustained release recombinant bovine somatotropin(SR-rbST) on dry matter intake(DM1) and nutrient intake of surgically castrated 32 Holstein young bulls by growth stage. The main results were as follows: 1. DM intakes were not different between in bull and steer groups, but those in rbSTl and rbST2 were 7.88 and 7.65kg respectively, which were lower 6-9% compared to bull and steer groups. 2. Actual DM intake to DM requirement of Beef cattle(NRC) was 88.5~97.7%, while net energy intake was sufficient for NE requirement in all groups during all growth stage except rbST group during fmishing stage. 3. Overall mean concentrate intake to body weight in steer group was the highest as 1.94%, and then those in rbST groups were 1.87~1.89% which were higher 0.07~0.09% unit than in bull group. 4. Feed conversion ratios(DM) in bull, rbSTl and rbST2 groups were 8.29, 8.18 and 7.60kg respectively, which were improved 12.4, 13.9 and 22.6%, respectively, compared to steer group.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.914-919
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• 2007

The effect of the addition of exogenous fibrolytic enzymes (mainly xylanase and cellulase activities, 15 ml/15 kg of fresh forage), on intake, total tract digestibility and nylon bag degradability of a chopped fresh Digitaria decumbens grass was studied at 2 stages of regrowth ( 21 and 56-day old grasses). Moreover, comparisons between ground and chopped grass were done using the nylon bag degradability method. DM intake (g/kg $BW^{0.75}$) and organic matter total tract digestibility for control and enzyme treatments respectively were 69.1 vs. 65.9 (p>0.05) and 0.723 vs. 0.727 (p>0.05) with the 21-day old regrowth. Based on the same parameters, values for the 56-day old grass were 58.1 vs. 52.7 (p>0.05) and 0.621 vs. 0.591 (p>0.05). Nylon bag degradation at 24 h of the dry matter for control versus enzyme treatments were 0.653 vs. 0.70 (p<0.05) and 0.644 vs. 0.733 (p<0.0001) for the 21-day old chopped and ground forage respectively, whereas with the 56-day old grass, corresponding values were 0.321 vs. 0.392 (p<0.0001) and 0.463 vs. 0.481 (p>0.05). The positive impact of exogenous fibrolytic enzymes (EFE) on degradability of the young and ground pangola grass may suggest that in some cases, enzyme accessibility to potentially digestible cell wall is a limiting factor in their digestion.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.1
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• pp.45-51
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• 1993

With the purpose to utilize cage layer manure (CLM), whole crop corn forage was ensiled with 30% CLM (MS silage) and without CLM (CS silage). MS silage was significantly (p < 0.05) higher in pH value, total VFA, propionic and butyric acids, and the ratio of ammonia nitrogen to total nitrogen, but lower (p < 0.05) in lactic acid and water soluble carbohydrate (WSC) contents than CS silage. Digestibility was evaluated using Shiba strain Japanese goats. Urea was supplemented to CS silage at feeding to adjust nitrogen intake to MS silage (US silage). There were no differences in digestibilities of dry matter (DM) and energy among the three silages. However, US silage showed higher (p < 0.05) digestibility of crude protein, but digestibilities of NDF, ADF, hemicellulose and cellulose were higher (p < 0.05) in MS silage. Nitrogen retention was positive in US and MS silages, but it was negative in CS silage. Voluntary feed intake of goats was 11.02, 12.03 and 13.34 g of DM per metabolic body weight ($kg^{0.75}$) for 10 minutes, for CS, US and MS silages, respectively.

• 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.15 no.4
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• pp.516-521
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• 2002

The objective of this study was to compare two varieties of Napier grass (Bana Napier grass vs French Cameroon Napier grass) and to determine whether feed intake, digestibility, average daily gain (ADG) and milk yield of lactating Friesian cows from fresh cut Bana Napier grass was greater than from French Cameroon Napier grass, using a completely randomized design. Results show that Bana Napier grass had similar percent dry matter (DM), ash and gross energy (GE) to French Cameroon. Bana grass had higher percent crude protein (CP) and lower fiber fractions, acid detergent fibre (ADF), neutral detergent fibre (NDF) and lignin compared to French Cameroon. Overall the forage quality was marginally higher in Bana Napier grass compared to French Cameroon. The DM and NDF intake expressed as a percentage of body weight (BW) were similar in both Napier grass types. Both grasses had similar digestible DM and energy. Bana had higher digestible CP but lower digestible ADF and NDF than French Cameroon. Bana Napier was not different from French Cameroon when fed as a sole diet to lactating cows in terms of low DM intake, milk yield and a loss of BW and condition. To improve the efficient utilization of both Napier grass varieties, a supplement capable of supplying 1085-1227 g CP/d and 17.0-18.0 Mcal ME/d is required for cows to support moderate gains 0.22 kg/d and 15 kg 4% fat corrected milk/d.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.57-71
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• 2009

Crop-livestock mixed farming systems depend on the efficiency with which nutrients are conserved and recycled. Home-grown forage is used as animal feed and animal excretions are applied to cultivated crop lands as manure. The objective of this study was to develop a mixed farming system model for dairy cattle in Japan. The model consisted of four sub-models: the nutrient requirement model, based on the Japanese Feeding Standards to determine requirements for energy, crude protein, dry matter intake, calcium, phosphorus and vitamin A; the optimum diet formulation model for determining the optimum diets that satisfy nutrient requirements at lowest cost, using linear programming; the herd dynamic model to calculate the numbers of cows in each reproductive cycle; and the whole farm optimization model to evaluate whole farm management from economic and environmental viewpoints and to optimize strategies for the target farm or system. To examine the model' validity, its predictions were compared against best practices for dairy farm management. Sensitivity analyses indicated that higher yielding cows lead to better economic results but higher emvironmental load in dairy cattle systems integrated with forage crop production.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.4
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• pp.260-265
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• 2018

Limited researches are available to demonstrate the effect of TMR (Total Mixed Ration) and SF (Separate feeding) system on ruminal methane production. Two experiments were performed at two different levels of daily feed intake (1.8 and 2.4% of BW) to investigate methane production by using a triplicated $2{\times}2$ Latin square design. Each experiment was conducted using six Holstein steers. Animals were provided either TMR or SF containing 73% concentrate and 27% forage, with the same ration of same ingredients. No differences in daily methane productions (MP) and per dry matter intake (DMI) were observed in both experiments. Relationship for daily methane production on DMI was $MP(g/d)=11.5({\pm}1.3){\times}DMI(kg/d)+14.2$, $R_2=0.73$, p<0.001.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.1
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• pp.35-40
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• 2021

This study was conducted to evaluate the forage productivity and feed value of Sasa borealis (S. borealis) using growing black goats(S. borealis) in order to improve the utilization of S. borealis and to help mitigate the problem of reduced plant species diversity caused by S. borealis in Hanlla Mountain. One control and three treatments were made by the level of addition of S. borealis silage to the TMR feed. T1(10%), T2(20%), and T3(30%) treatments showed more daily weight gains than control group. Feed conversion ratio of T2 is 4.4g, which is significantly lower than control(P<0.05). The nitrogen retention in the control, which had relatively high dry matter intake, was 12.5g, which was significantly higher than that of T3. Sasa. borealis silage is considered to be able to use as a forage source for black goats, and if it is fed in an appropriate amount, it is considered that it will help improve livestock productivity, such as weight gain and feed conversion ratio.