• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.214-221
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• 2011

Effects of the cell wall-degrading enzymes derived from Acremonium cellulolyticus and Trichoderma viride on the silage fermentation and in sacco degradation of tropical grasses i.e. rhodesgrass (Chloris gayana Kunth. cv. Callide) and guineagrass (Panicum maximum Jacq. cv. Natsukaze) were investigated in laboratory-scale experiments. These two grasses were either treated with or without the enzymes before ensiling. Untreated rhodesgrass produced acetate fermentation silage (lactate, $13.0\;g\;kg^{-1}$ DM; acetate, $38.7\;g\;kg^{-1}$ DM) with high final pH value and $NH_3$-N content (5.84 and $215\;g\;kg^{-1}$ DM). Addition of enzymes significantly increased (p<0.01) the lactate production (lactate, 45.6; acetate, $34.0\;g\;kg-^{1}$ DM) and decreased (p<0.01) the pH and $NH_3$-N (4.80 and $154\;g\;kg^{-1}$ DM) in the ensiled forages when compared with the control silages. Untreated guineagrass was successfully preserved with a high lactate proportion (lactate, 45.5; acetate, $24.1\;g\;kg^{-1}$ DM), and the addition of enzymes further enhanced the desirable fermentation (lactate, $57.5\;g\;kg^{-1}$ DM; acetate, $19.4\;g\;kg^{-1}$ DM). The content of NDF was lowered (p<0.05) by enzymes in both silages, but the extent appeared greater in the enzyme-treated rhodesgrass (rhodesgrass, $48\;g\;kg^{-1}$ DM; guineagrass, $21\;g\;kg^{-1}$ DM). Changes in the kinetics of in sacco degradation showed that enzyme treatment increased (p<0.01) the rapidly degradable DM (rhodesgrass, 299 vs. $362\;g\;kg^{-1}$ DM; guineagrass, 324 vs. $343\;g\;kg^{-1}$ DM) but did not influence the potential degradation, lag time and degradation rate of DM and NDF in the two silages.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.522-529
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• 1998

This experiment was conducted to study the effects of lactic acid bacteria (LAB) inoculation either alone or in combination with cell wall degrading enzymes on the fermentation characteristics and chemical compositions of Rhodesgrass silage. Over to 1 kg of fresh Rhodesgrass sample a treatment of inoculant LAB with or without addition of an enzyme of Acremoniumcellulase (A) or Meicelase (M) or a mixture of both enzymes (AM) was applied. The treatments were control untreated, LAB-treated (application rate $1.0{\times}10^5cfu/g$ fresh sample), LAB+A 0.005%, LAB+A 0.01%, LAB+A 0.02%, LAB+M 0.005%, LAB+M 0.01%, LAB+M 0.02 %, LAB+AM 0.005%, LAB+AM 0.01%, and LAB+AM 0.02%. The sample was ensiled into 2-L vinyl bottle silo, with 9 silages of each treatment were made. Three silages of each treatment were incubated at 20, 30 and $40^{\circ}C$ for 2-months of storage period. All silages were well preserved with their fermentation quality has low pH values (3.91-4.26) and high lactic acid concentrations (4.11-9.89 %DM). No differences were found in fermentation quality and chemical composition of the control untreated silage as compared to the LAB-treated silage. Combined treatment of LAB+cellulases improved the fermentation quality of silages measured in terms of lower (p < 0.01) pH values and higher (p < 0.05) lactic concentrations than those of LAB-treated silages. Increasing amount of cellulase addition resulted in decrease (p < 0.05) of pH value and increase (p < 0.05) of lactic acid concentration. LAB + cellulase treatments (all cellulase types) reduced (p < 0.01) NDF, ADF and in vitro dry matter digestibility of silages compared with the control untreated silages. The fermentation quality and the rate of cell wall reduction were higher (p < 0.01) in the silages treated with LAB + cellulase A than in the silages treated with either LAB+cellulase M or LAB + cellulase AM. Incubation temperature of $40^{\circ}C$ was likely to be more appropriate environment for stimulating the fermentation of Rhodesgrass silages than those of 20 and $30^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.531-536
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• 1999

This study was conducted to compare the effects of lactic acid bacteria (LAB) or LAB+cellulases on the cell wall compositions and the in vitro dry matter digestibility (IVDMD) of Rhodesgrass (RG) and Italian ryegrass (IRG) silages. LAB (Lactobacillus cassei) at a concentration of $10{\times}10^5\;cfu.g^{-1}$ fresh forage was added to all ensiling samples (except the untreated control) of RG and IRG. The cellulases used were Acremoniumcellulase (A), Meicelase (M) or a mixture of both (AM). Each cellulase was applied at levels of 0.005, 0.01 and 0.02 % fresh sample. The samples were incubated at 20, 30 and $40^{\circ}C$ for about 2 months of storage. LAB inoculation did not affect cell wall components or IVDMD of both the RG and IRG silages, but LAB+cellulase treatments did. Increasing the amount of cellulase addition resulted in further decreases of cell wall concentrations. This reduction more markedly occurred with cellulases A and AM than it did with cellulase M. Cell wall components losses were higher in the IRG silages than in the RG silages. LAB+cellulase treatments decreased IVDMD of the RG silages, but had no effect on the IRG silages. The different effect of LAB+cellulase treatments on cell wall degradation and IVDMD of the RG and IRG silages suggested that RG contains more structural carbohydrates, which were difficult to degrade with cellulase, than did IRG.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.214-219
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• 2008

An experiment was conducted to evaluate the effects of nitrogen (N) level on the dry matter (DM) yield, N concentration and oxalate content of some tropical grasses, namely Rhodesgrass (Chloris gayana), Guineagrass (Panicum maximum) and Sudangrass (Sorghum vulgare). Three levels of N as urea were applied (Standard- 260, $Standard{\times}2$- 540 and$Standard{\times}4$- 1,060 kg N/ha for Rhodesgrass; Standard- 380, $Standard{\times}2$- 770 and $Standard{\times}4$- 1,570 kg N/ha for Guineagrass and Sudangrass) in a completely randomized design and grasses were harvested twice at approximately two-month intervals. Dry matter yield tended to be higher with increased rate of N fertilizer in all species, while further additional N ($Standard{\times}2$ or $Standard{\times}4$) did not significantly (p>0.05) further increase DM yield, when compared with the Standard level of N fertilizer application. There was also a trend towards higher N concentration in plants as N fertilization increased in all species and it was increased significantly in Rhodesgrass and Sudangrass (p<0.05 or p<0.01, respectively). Further additional N ($Standard{\times}2$ or $Standard{\times}4$) application showed no significant (p>0.05) differences on oxalate content in plant tissue within species, when compared with the Standard level of N. The Rhodesgrass contained 0.11, 0.13 and 0.15% soluble oxalate and 0.23, 0.25 and 0.27% total oxalate with Standard, $Standard{\times}2$ and $Standard{\times}4$ level of N application, respectively. The Guineagrass contained 0.54, 0.50 and 0.42% soluble oxalate and 1.60, 1.56 and 1.45% total oxalate with Standard, $Standard{\times}2$ and $Standard{\times}4$ level of N application, respectively. The Sudangrass contained 0.06, 0.15 and 0.12% soluble oxalate and 0.22, 0.22 and 0.21% total oxalate with Standard, $Standard{\times}2$ and $Standard{\times}4$ level of N application, respectively The results from this study suggest that these grasses do not use further addition of N fertilizer ($Standard{\times}2$ or $Standard{\times}4$) to form high content of oxalate salts, when compared with the Standard level of N. In addition, the levels of oxalate present with these grasses are quite low as far as toxicity to animals is concerned.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.525-530
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• 1999

Prior to ensiling Rhodesgrass (RG) and Italian ryegrass (lRG) were treated with lactic acid bacteria (LAB) or with LAB+cellulases to compare their fermentation characteristics and chemical compositions. LAB (Lactobacillus casei) was added to all ensiling materials (except the untreated control) of RG and IRG at a concentration of $1.0{\times}10^5\;cfu.g^{-1}$ fresh forage. The enzymes used were Acremoniumcellulase (A), Meicelase (M) or a mixture of both (AM). Each enzyme was applied at levels of 0.005, 0.01 and 0.02 % of fresh forage. The silages with each treatment were incubated at 20, 30 and $40^{\circ}C$ and stored for about 2 months. While no marked differences were found between the RG and IRG silages with various treatments on dry matter (DM), volatile basic nitrogen (VBN) and water soluble carbohydrate (WSC) contents, there were significant differences in pH value, and lactic acid and butyric acid contents. LAB inoculation did not affect the fermentation characteristics of either the RG or IRG silages. The combined treatments of LAB+cellulases improved the fermentation quality of both the RG and IRG silages as evidenced by the decrease in pH value and increase in lactic acid content. Increasing the amount of added cellulase resulted in a decrease in pH value and an increase in lactic acid content in both the RG and IRG silages. Cellulases A and AM had a greater effect than cellulase M on the fermentation quality of the RG and IRG silages. Incubation temperatures of 30 and $40^{\circ}C$ appeared to be more appropriate environments for stimulating good fermentation than $20^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.920-924
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• 2007

Two experiments were carried out on a laboratory scale. The first involved a study of the effect of green tea on characteristics of fermented juice of epiphytic lactic acid bacteria (FJLB). FJLB was treated with 50 g/L of green tea products as follows: new shoot powder (FJLB+N), leaf powder (FJLB+L), commercial powder (FJLB+P), sterilized new shoot powder (FJLB+SN), sterilized leaf powder (FJLB+SL) or sterilized commercial powder (FJLB+SP). FJLB without any additive was also prepared (Untreated FJLB). After incubation, the number of microorganisms in FJLB were studied. Subsequently, these FJLB were applied at 10 ml/kg to chopped rhodesgrass to study their effects on fermentation. Compared with untreated FJLB, the addition of green tea increased (p<0.05) lactic acid bacteria (LAB) and also aerobic bacteria counts in FJLB. At 60 d of ensiling, all the FJLB treated silages were well preserved, pH and butyric acid content were lower (p<0.001) and lactic acid was higher (p<0.001) than that of the control. Lactic acid content was significantly higher (p<0.001) with treated FJLB than with untreated FJLB. FJLB treated with sterilized green tea decreased (p<0.001) the pH and the lactic acid content was higher (p<0.001) than that in the unsterilized green tea silages.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.2
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• pp.121-127
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• 1998

Thirty two Omani sheep with eight animals each of; intact males (INT), males castrated with rubber rings immediately after birth (RR), males castrated with a burdizzo at 8 weeks of age (BC) and intact females (IF) were fed ad libitum a concentrate diet (CP 16%) plus chopped Rhodesgrass hay (8% CP) from weaning until slaughter at 28 kg. INT lambs grew faster from 9 to 20 weeks of age (p < 0.05) thus they were significantly heavier at 20 weeks of age than BC and IF, but not RR lambs. INT consumed more total feed than other sex groups over the period from 9 to 20 weeks of age. There were no significant differences between lambs of all experimental groups in feed per gain ratio. INT lambs had lower (p < 0.01) dressing percentage (DP) than RR, BC and IF. As a percentage in the empty body weight (EBW), INT had higher proportions of head, feet, empty gut (p < 0.001), liver (p < 0.05) and genitals (p < 0.05) but lower proportions of lungs and trachea (p < 0.05) than BC and IF lambs. INT males had a significantly higher (p < 0.05) proportion of bone than RR and IF lambs but lower (p < 0.05) proportion of fat than RR and IF. As a percentage in EBW, IF had the highest protortion (p < 0.001) of total body fat (TBF) followed by BC and RR whereas INT males had the lowest proportion. There was a general trend of IF having the highest proportion of individual and total non-carcass fat (TNCF) and total carcass fat (TCF) followed by BC and RR lambs whereas INT lambs had the lowest protortions of individual carcass and non-carcass fat depots. There were only few sex or castration effects on carcass tissue distribution. IF had higher proportions of intermuscular fat in the chuck, plate, leg and flank than INT and BC. The current study demonstrated that castration of intensively-raised male Omani native sheep especially at weaning using a burdizzo retarded growth rate and reduced carcass quality by increasing fat content.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.6
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• pp.611-616
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• 1995

A study was conducted which demonstrated that Dhofari cattle responded well to intensive management systems in terms of growth rates and carcass yields. Twenty-four Omani Dhofari bulls and steers (12 of each) were reared from birth until slaughter at 110, 160 and 210 kg body weight (for of each sex at each slaughter weight). Calves were fed ad libitum a diet of concentrate (16.5% CP) and Rhodesgrass hay (8.8% CP). Bulls and steers reached the predetermined slaughter weights of 110, 160 and 210 kg at 154 and 164; 219 and 233; 273 and 310 days of age, respectively. Respective mean pre and post-weaning daily body weight gains for bulls and steers were 581 and 530; 796 and 706 g averaging 645 and 596 g over 36 weeks. At 210 kg, the heaviest weight of the study, dressing-out percentage (DO) was 54.5 and 56.9 yielding carcasses of 115.9 and 118.5 kg which contained 60.4 and 61.5% muscle; 11.6 and 11.4% bone and 24.5 and 22.9% fat for bulls and steers, respectively. Proportion of bone in the carcass decreased, that of fat increased, whereas that of muscle remained unchanged between slaughter weights of 110 to 210 kg. That resulted in increased muscle : bone and decreased muscle : fat ratios. At 160 kg body weight, bulls had less fat and more muscle and bone than steers but there were no sex differences in carcass composition at 210 kg slaughter weight.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.967-973
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• 2000

A metabolism trial was conducted with 28 Najdi rams allocated into seven dietary groups to evaluate the effect of dietary inclusion of Salicornia bigelovii Torr biomass on nutrient digestibility, rumina I fluid metabolites and nitrogen and mineral balances. Either the stems (ST) or spikes (SP) of this seawater-irrigated halophyte were incorporated into complete diets at rates of 0, 10, 20 and 30% levels, replacing equal amounts of rhodesgrass hay in a ground mixed control diet. Digestibility of DM, OM, EE, NFE and fecal and urinary nitrogen were not affected by increased level of ST in the diet. As level of ST increased from 0 to 20% in the diets, CP digestibility and nitrogen retention approached their maximum (p<0.01), whereas CF digestibility reached its minimum (p<0.01). On the other hand, except for EE, digestion of all nutrients and nitrogen retention were linearly depressed (p<0.01) as SP increased in the diets from 10 to 30% level. Concentration of ammonia-N, total VFA and pH values in the rumen fluid were lower (p<0.01) with the ST- or SP-fed diets than with the control diet. Increasing level of ST or SP in the diet was associated with an increase (p<0.01) in the proportion of acetate and a decline (p<0.01) in molar percentage of propionate in the ruminal fluid. Sodium absorption increased (p<0.01) with increased ST and SP in the diets up to the 10 and 20% level, respectively, followed by constant absorption values up to the 30% level. When the level of ST in the diet gradually increased to 30%, a concomitant increased (p<0:01) in Ca and P absorption were obvious; whereas, increased level of SP in the diets from 0 to 30% resulted in noticeable (p<0.01) depression in Ca and P apparent absorption.