• Journal of Dairy Science and Biotechnology
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• 제19권1호
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• pp.1-3
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• 2001

This study was conducted to increase the content of taurine in milk from the dairy cows fed the rumen protected DL-methionine matrix and methionie hydroxy analog matrix for 42days. Dairy cows fed rumen protected DL-methionine matrix showed 23% increased milk taurine concentration compared to the value of the control groups. Dairy cows fed rumen protected methionine hydroxy analog matrix showed 53% increased milk taurine concentration compared to the value for the control groups (p<0.01).

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.247-248
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.279-288
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• 1994

Three experiments were conducted with female Japanese Saanen goats to investigate the effects of rumen protected methionine (RPMet) on N utilization and whole-body protein turnover. Whole-body leucine flux from which whole-body protein turnover rates were derived was measured by primed- continuous infusion of L-[$^{15}N$] leucine in combination with gas chromatography-mass spectrometry. Throughout the experiments RPMet was added to a diet to supply 1.5 g DL-methionine per goat per day. Irrespective of the major N sources (i.e., protein or urea) in the diet, both N deposition and whole-body protein synthesis were increased (p<0.05), and urinary N excretion was decreased (p<0.05) by supplementing with RPMet, but not by supplementing with methionine. It was concluded, therefore, that under the present experimental conditions, the RPMet supplement was efficiently bypassed to result in enhanced body protein synthesis of the goat.

• Asian-Australasian Journal of Animal Sciences
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• 제13권9호
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• pp.1235-1238
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• 2000

Thirty-six Holstein dairy cows were used to evaluate the effect of a rumen protected methionine supplement (RPMet). The cows were divided into two groups of 18 each (control/experimental). The experimental group was given 15 g/d of RPMet (Mepron $^{(R)}$M85, Degussa) from the 4th to the 26th week postpartum. All cows were fed a similar amount of forage including alfalfa silage, corn silage and timothy silage. Concentrate mixture was offered in proportion to the milk yield of each cow. Sufficiency of major metabolizable AAs was checked. Milk yield and milk composition was monitored for each individual cow. A metabolic profile test (MPT) was carried out at the 7th, 11th and 21st week postpartum. Without supplement, both methionine and leucine fell short of the daily requirement. Supplementation with 15 g/d RPMet was calculated to be within a sufficient margin of safety. Milk yield tended to remain higher in the supplemented group than in the controls during supplementation with RPMet. The differences in weekly milk production at the 17th, 18th, 19th and 22nd weeks postpartum were significantly high in the RPMet group (p<0.05). The average 305-d milk yield and the percentages of milk fat, milk protein and solids-not-fat were not affected by the treatment. No differences were observed in either the somatic cell count in the milk or the reproductive status. Judging from MPT, all the cows were in good health during lactation.

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.544-545
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• 제9권2호
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• pp.223-229
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• 1996

This experiment was conducted to investigate the protein sparing effect of rumen protected lysine(RPLys) and methionine hydroxyl analogue(MHA) in sheep. The treatments were $T_1$ (CP 15% + RPLys 0%), $T_2$ (CP 12% + RPLys 0%), $T_3$ (CP 12% + RPLys 0.4%) and $T_4$ (CP 12% + RPLys 0.4% + MHA 0.3%). Ruminal characteristics, in situ and in vitro digestibility and nitrogen retention rate were measured in sheep receiving different combinations of dietary supplement. The results are summarized as follows: 1. Ruminal pH and VFA concentrations were not affected by the treatments. Ruminal ammonia-N concentration was high in sheep fed diets $T_2$, $T_3$ and $T_4$ with the highest value in the $T_4$ treatment(p<0.05). 2. The digestibilities of dry matter and organic matter were not affected by the treatments. 3. Nitrogen losses through feces and urine were the highest with $T_1$ (p<0.05) and nitrogen retention rates of groups $T_1$, $T_2$, $T_3$ and $T_4$ were 18.6, 32.4, 35.5 and 27.5% of nitrogen intake, respectively, indicating that RPLys supplementation improved nitrogen retention in sheep.

• Asian-Australasian Journal of Animal Sciences
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• 제22권5호
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• pp.659-666
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• 2009

Metabolizable protein (MP) supply and amino acid balance in the intestine were manipulated through selection of highly digestible rumen-undegradable protein (RUP) sources and protected methionine (Met) supplementation. Four ruminallycannulated, multiparous Holstein cows averaging 193${\pm}$13 days in milk were used in a 4${\times}$4 Latin square design to assess N utilization and milk production responses to changes in RUP level, post-ruminal RUP digestibility and protected Met supplementation. Treatments were A) 14.0% crude protein (CP), 8.0% rumen degradable protein (RDP) and 6.0% RUP of low intestinal digestibility (HiRUP-LoDRUP); B) 14.1% CP, 8.1% RDP and 6.0% RUP of high intestinal digestibility (HiRUP-HiDRUP); C) 13.1% CP, 7.9% RDP and 5.2% RUP of high intestinal digestibility (LoRUP-HiDRUP), and D) 13.1% CP, 7.9% RDP and 5.2% RUP of high intestinal digestibility plus rumen escape sources of Met (LoRUP-HiDRUP+Met). Experimental diets were formulated to have similar concentrations of RDP, net energy of lactation ($NE_L$), neutral detergent fiber (NDF), acid detergent fiber (ADF), calcium, phosphorus and ether extract using the NRC model (2001). Results showed that dry matter intake (DMI), production of milk fat and protein were similar among treatments. Milk production was similar for diet HiRUP-LoDRUP, HiRUP-HiDRUP and LoRUP-HiDRUP+Met, and significantly higher than diet LoRUP-HiDRUP. Milk fat and protein percentage were higher for cows receiving HiDRUP treatments, with the greatest increases in the diet LoRUP-HiDRUP+Met. There was no significant change in ruminal pH, $NH_3g-N$ and volatile fatty acid (VFA) concentration among all treatments. Apparent digestibility of dry matter (DM), CP, NDF and ADF and estimated bacterial CP synthesis were similar for all treatments. Nitrogen intakes, blood and milk urea-N concentrations were significantly higher for cows receiving HiRUP diets. Urine volume and total urinary N excretion were significantly lowered by LoRUP diets. Lowering dietary RUP level while supplementing the highly digestible RUP source with rumen escape sources of Met resulted in similar milk production, maximal milk fat and protein concentration and maximum N efficiency, indicating that post-ruminal digestibility of RUP and amino acid balance in the small intestine can be more important than total RUP supplementation.

• Animal Bioscience
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• 제35권10호
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• pp.1556-1565
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• 2022

Objective: Tan lambs (n = 36, 3 mo old, 19.1±0.53 kg) were used to assess effects of dietary guanidinoacetic acid (GAA) and rumen-protected methionine (RPM) on growth performance, carcass traits, meat quality, and serum parameters. Methods: Lambs were randomly assigned to three treatment groups, with 6 pens per group and 2 lambs per pen. Dietary treatments were: basal diet alone (I); basal diet supplemented with 0.08% GAA+0.06% RPM (II); and basal diet supplemented with 0.08% GAA+0.08% RPM (III). Diets were provided three times a day for 90 d. Intake per pen was recorded daily and individual lamb body weight (BW) was measured monthly. Carcass traits were measured after slaughter and meat quality at the end of the experiment, blood samples were taken on a subgroup of lambs for analysis of indicators mostly related to protein metabolism. Results: Final BW and average daily gain for the first and second month, and for the entire experiment were greater in Treatment II compared to Treatment I (p<0.05), whereas feed to gain ratio was lower (p<0.05). Treatment II had the optimal dressing percentage and net meat weight proportion, as well as crude protein and intramuscular fat concentrations in muscles. Treatment II improved meat quality, as indicated by the greater water holding capacity, pH after 45 min and 48 h, and lower shear force and cooking loss. Dietary supplementation of GAA and RPM also increased the meat color a^* and b^* values at 24 h. Finally, Treatment II increased total protein, and serum concentrations of albumin and creatinine, but decreased serum urea nitrogen concentrations, indicating improved protein efficiency. Conclusion: In this study, 0.08% GAA+0.06% RPM supplementation improved growth performance and meat quality of Tan lambs.

• 농업과학연구
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• 제48권4호
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• pp.669-679
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• 2021

This study was conducted to evaluate the effects of rumen-protected amino acid (RPAA) prototypes, which were chemically synthesized, on in vitro rumen fermentation and protection rate outcomes. Several RPAA prototypes were incubated with timothy hay and concentrate. Treatments consisted of 1) control (CON; no RPAA prototype supplement), and prototypes of 2) 0.5% RP-methionine (RPMet), 3) 0.5% RP-tryptophan (RPTrp), 4) 0.5% RP-valine (RPVal), 5) 0.5% RP-phenylalanine (RPPhe), 6) 0.5% RP-leucine (RPLeu), 7) 0.5% RP-histidine (RPHis), 8) 20% RPMet, and 9) 20% RPTrp (w·w^-1 feed). The inoculum (50 mL) prepared with rumen fluid and McDougall's buffer (1 : 4) was dispensed in individual serum bottles and was anaerobically incubated for 0, 6, and 24 h at 39℃ in triplicate. The dry matter degradability did not differ among the groups, except for the 20% RPMet and the 20% RPTrp treatments at 6 and 24 h. The total volatile fatty acid concentration in the 20% RPMet was higher (p < 0.05) than the rest of the groups at 6 h, and 20% RPMet showed the highest molar proportion of acetate, whereas the lowest proportion of propionate was found at 6 h (p < 0.05). The protection rate of the RPAA prototypes ranged from 29.85 to 109.21%. at 24 h. In conclusion, the chemically synthesized RPAA prototypes studied here had no detrimental effects on rumen fermentation parameters. Further studies using animal models are needed for more accurate evaluations of the effectiveness of RPAA.

• Asian-Australasian Journal of Animal Sciences
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• 제27권12호
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• pp.1705-1711
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• 2014

The objective of this study was to evaluate the effect of ruminally protected amino acids (RPAAs) and ruminally protected fat (RPF) supplementation on ruminal fermentation characteristics (in vitro) and milk yield and milk composition (in vivo). Fourteen mid-lactating Holstein dairy cows (mean weight $653{\pm}62.59kg$) were divided into two groups according to mean milk yield and number of days of postpartum. The cows were then fed a basal diet during adaptation (2 wk) and experimental diets during the treatment period (6 wk). Dietary treatments were i) a basal diet (control) and ii) basal diet containing 50 g of RPAAs (lysine and methionine, 3:1 ratio) and 50 g of RPF. In rumen fermentation trail (in vitro), RPAAs and RPF supplementation had no influence on the ruminal pH, dry matter digestibility, total volatile fatty acid production and ammonia-N concentration. In feeding trial (in vivo), milk yield (p<0.001), 4% fat corrected milk (p<0.05), milk fat (p<0.05), milk protein (p<0.001), and milk urea nitrogen (p<0.05) were greater in cows fed RPAAs and RPF than the corresponding values in the control group. With an index against as 0%, the rates of decrease in milk yield and milk protein were lower in RPAAs and RPF treated diet than those of basal diet group (p<0.05). In conclusion, diet supplemented with RPAAs and RPF can improve milk yield and milk composition without negatively affecting ruminal functions in Holstein dairy cows at mid-lactating.