• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.131-142
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• 2003

We evaluated the effects of adding fibrolytic enzyme into ruminant diets on ruminal fermentation (in vitro) and lactational performances of dairy cows (in vivo). Through the in vitro experiment that was carried out with different contents of NDF (34, 38, 43%) in diets, digestibilities of NDF in the rumen appeared not significantly different by the addition of enzyme but were different by NDF content in diets showing higher digestibility in NDF 43% diet. It could be attributed by the relatively higher amount of hemicellulose in the current experimental diets than in conventional diets that might have been digested easily by the addition of fibrolytic enzyme in the rumen. The addition of fibrolytic enzyme tended to increase NDF digestibilities to a little extent both in 0.05 and 0.1% enzyme levels. Ruminal pH, NH3-N concentrations and VFA production in the rumen were not affected by the addition of fibrolytic enzyme. Activities of CMCase and xylanase were higher in enzyme treated diets of both NDF 34 and 38%. In particular, the activities of xylanase that slowly decreased from 0 to 12 hr but rapidly after 24 hr indicates that the major action of the enzyme in the rumen occurs in early period of incubation. Through an in vivo experiment, fibrolytic enzyme addition into the diets of dairy cows indeed affected lactational performance of milk yield. The cows fed enzyme treated diets produced 8% (1.9kg/d) more amounts of milk than with no enzyme addition. Milk composition of milk fat and protein was not affected by enzyme addition. Overall, the results of this in vivo study indicates that fibrolytic enzyme can be used to improve milk production in lactating cows. In respect that animals in different treatments of this study had the same amounts of intake, the increased milk yield with enzyme addition may be attributed to the improved utilization of nutrients in the digestive tract.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.536-542
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• 2007

The responses of whole body protein and glucose kinetics and of nitrogen (N) metabolism to non-protein energy intake (NPEI) were determined using an isotope dilution approach and measurement of N balance in three adult male goats. The diets containing 1.0, 1.5 and 2.0 times ME maintenance requirement, with fixed intake of CP (1.5 times maintenance) and percentage of hay (33%), were fed twice daily for each 21 d experimental period. After an adaptation period of 11 d, N balance was determined over 3 d. On day 17, whole body protein synthesis (WBPS) and glucose irreversible loss rate (ILR) were determined during the absorptive state by a primed-continuous infusion of [$^2H_5$]phenylalanine, [$^2H_2$]tyrosine, [$^2H_4$]tyrosine and [$^{13}C_6$]glucose, with simultaneous measurements of plasma concentrations of metabolites and insulin. Ruminal characteristics were also measured at 6 h after feeding over 3 d. Nitrogen retention tended to increase (p<0.10) with increasing NPEI, although digestible N decreased linearly (p<0.05). Increasing NPEI decreased (p<0.01) ammonia N concentration, but increased acetate (p<0.05) and propionate (p<0.05) concentrations in the rumen. Despite decreased plasma urea N concentration (p<0.01), increased plasma tyrosine concentration (p<0.05), and trends toward increased plasma total amino N (p<0.10) and phenylalanine concentrations (p<0.10) were found in response to increasing NPEI. Increasing NPEI increased ILR of both glucose (p<0.01) and phenylalanine (p<0.05), but did not affect ($p{\geq}0.10$) that of tyrosine. Whole body protein synthesis increased (p<0.05) in response to increasing NPEI, resulting from increased utilization rate for protein synthesis (p<0.05) and unchanged hydroxylation rate of phenylalanine ($p{\geq}0.10$). These results suggest that increasing NPEI may enhance WBPS and glucose turnover at the absorptive state and improve the efficiency of digestible N retention in goats, with possibly decreased ammonia and increased amino acid absorption. In addition, simultaneous increases in WBPS and glucose ILR suggest stimulatory effect of glucose availability on WBPS, especially when sufficient amino acid is supplied.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1098-1106
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• 2004

In a split-unit design, 12 Javan rusa (Cervus timorensis russa) stags (6 castrated and 6 entire) were used to investigate seasonal (winter, spring and summer) effects on intake, digestibility of food constituents, volatile fatty acid profile, and nitrogen retention, when given lucerne (Medicago sativa) or rhodes grass (Chloris guyana) hays. Entire stags ate 9% more dry matter (DM) than castrates (p<0.05). Both castrated and entire stags exhibited seasonal changes in DM intake, these being higher (p<0.05) in winter (62.3 g/kg $W^{0.75}$) than spring (56.9 g/kg $W^{0.75}$) or summer (55.3 g/kg $W^{0.75}$). Intakes of lucerne hay (211 g protein/kg DM) were significantly higher than of rhodes grass hay (49 g protein/kg DM) in all seasons (p<0.05). Digestibilities of DM (0.58), neutral detergent fibre (0.59) and acid detergent fibre (0.47) were similar between castrates and entires. DM digestibility was higher (p<0.0001) for lucerne (0.66) than rhodes grass (0.55), and was higher (p<0.05) in winter (0.60) than spring (0.58) or summer (0.57). The ruminal acetate concentrations were higher (p<0.001) in spring than summer (78 and 73 molar % respectively). Apparent digestibility of protein was significantly less (p<0.0001) for rhodes grass (0.37) than lucerne (0.75). N retention was positive for lucerne (15.2 g/d) but negative for rhodes grass (-2.8 g/d) (p<0.0001), and was higher (p<0.001) in summer (12.0 g/d) than spring (4.3 g/d) or winter (2.4 g/d). The tropical rusa deer exhibits seasonal variations in feed intake, food constituent digestibilities, VFA profile and N retention. Castration did not alter these traits. The results do not support the view that rusa deer can thrive on low-quality pastures. The productivity and commercial exploitation of rusa deer could be optimised if they are given high-protein feed during spring and summer.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.11
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• pp.1604-1609
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• 2008

A series of in vitro and in vivo experiments were conducted to investigate the effects of the mixture of Tween 80 and cellulolytic enzymes (xylanase and cellulase) on total tract nutrient digestibility and rumen cellulolytic bacterial adhesion rates in Holstein steers. Ground timothy hay sprayed with various levels of Tween 80 and cellulolytic enzymes was used as substrates in an in vitro experiment to find out the best combinations for DM degradation. The application level of 2.5% (v/w) Tween 80 and the combination of 5 U xylanase and 2.5 U cellulase per gram of ground timothy hay (DM basis) resulted in the highest in vitro dry matter degradation rate (p<0.05). Feeding the same timothy hay to Holstein steers also improved in vivo nutrient (DM, CP, CF, NDF and ADF) digesibilities compared to non-treated hay (p<0.05). Moreover, Tween 80 and enzyme combination treatment increased total ruminal VFA and concentrations of propionic acid and isovaleric acid with decreased acetate to propionate ratio (p<0.001). However, adhesion rates of Fibrobacter succinogenes and Ruminococcus flavefaciens determined by Real Time PCR were not influenced by the treatment while that of Ruminococcus albus was decreased (p<0.05). The present results indicate that a mixture of Tween 80 and cellulolytic enzymes can improve rumen environment and feed digestibility with variable influence on cellulolytic bacterial adhesion on feed.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.617-626
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• 2003

This experiment employed a rumen simulated continuous culture system to examine the possibility of improving the rumen bypass of polyunsaturated fatty acids (PUFA) by using a high proportion of concentrate in the feed, and compared soya and linseed in terms of conjugated linoleic acid (CLA) production. No effect of type of fat source was observed on ruminal fermentation. A high proportion of concentrate (80%) in the feed decreased (P<0.001) vessel pH but increased (P<0.01) ammonia nitrogen, total VFA, acetate, butyrate and valerate concentrations compared with a low proportion (40%). Fat sources (soya vs. linseed) and concentrate ratio in the feed did not affect digestibilities of organic matter (OM), total nitrogen, neutral detergent fiber (NDF) and acid detergent fiber (ADF). Soya increased the flows of trans C18:1, C18:2 n-6 and C18:3 n-3 compared with linseed. The difference in fat source alone did not affect the flow of CLA but this was increased when high levels of soya and linseed were associated with a high proportion of concentrate in the feed. There was no effect of fat source on biohydrogenation of C18:1 n-9 and C18:2 n-6, but biohydrogenation of C18:3 n-3 and total C18 PUFA was higher with the linseed than with the soya treatment. A high proportion of concentrate decreased biohydrogenation of C18:2 n-6, C18:3 n-3 and total C18 PUFA compared with a low proportion.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.1
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• pp.50-57
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• 2015

This study was conducted to investigate the effect of soybean meal (SM) and soluble starch (SS) on biogenic amine production and microbial diversity using in vitro ruminal fermentation. Treatments comprised of incubation of 2 g of mixture (expressed as 10 parts) containing different ratios of SM to SS as: 0:0, 10:0, 7:3, 5:5, 3:7, or 0:10. In vitro ruminal fermentation parameters were determined at 0, 12, 24, and 48 h of incubation while the biogenic amine and microbial diversity were determined at 48 h of incubation. Treatment with highest proportion of SM had higher (p<0.05) gas production than those with higher proportions of SS. Samples with higher proportion of SS resulted in lower pH than those with higher proportion of SM after 48 h of incubation. The largest change in $NH_3$-N concentration from 0 to 48 h was observed on all SM while the smallest was observed on exclusive SS. Similarly, exclusive SS had the lowest $NH_3$-N concentration among all groups after 24 h of incubation. Increasing methane ($CH_4$) concentrations were observed with time, and $CH_4$ concentrations were higher (p<0.05) with greater proportions of SM than SS. Balanced proportion of SM and SS had the highest (p<0.05) total volatile fatty acid (TVFA) while propionate was found highest in higher proportion of SS. Moreover, biogenic amine (BA) was higher (p<0.05) in samples containing greater proportions of SM. Histamines, amine index and total amines were highest in exclusive SM followed in sequence mixtures with increasing proportion of SS (and lowered proportion of SM) at 48 h of incubation. Nine dominant bands were identified by denaturing gradient gel electrophoresis (DGGE) and their identity ranged from 87% to 100% which were mostly isolated from rumen and feces. Bands R2 (uncultured bacterium clone RB-5E1) and R4 (uncultured rumen bacterium clone L7A_C10) bands were found in samples with higher proportions of SM while R3 (uncultured Firmicutes bacterium clone NI_52), R7 (Selenomonas sp. MCB2), R8 (Selenomonas ruminantium gene) and R9 (Selenomonas ruminantium strain LongY6) were found in samples with higher proportions of SS. Different feed ratios affect rumen fermentation in terms of pH, $NH_3$-N, $CH_4$, BA, volatile fatty acid and other metabolite concentrations and microbial diversity. Balanced protein and carbohydrate ratios are needed for rumen fermentation.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.1
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• pp.65-71
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• 2013

Two digestion trials, one with sheep and another with goats, were conducted to evaluate the long-term bias (LTB) of the indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) internal markers. The study used eight Santa In$\hat{e}$s castrated male sheep (average body weight of 16.6 kg) distributed in two $4{\times}4$ Latin squares and eight Saanen castrated male goats (average body weight of 22.6 kg) distributed in two $4{\times}4$ Latin squares. The experiments were conducted simultaneously, and the animals were housed in 1.2 $m^2$ individual pens with wood-battened floors equipped with individual feeders and drinkers. The animals received isonitrogenous diets that were offered ad libitum and contained 14% crude protein and 70% sugar cane (with 0, 0.75, 1.5 or 2.25% CaO, in natural matter percentage), corrected with 1% urea and 30% concentrate. The experiment consisted of four experimental periods of 14 d each, with the feed, leftovers and feces sampled on the last four days of each period. The marker concentrations in the feed, leftovers and fecal samples were estimated by an in situ ruminal incubation procedure with a duration 240 h. The relationship between the intake and excretion of the markers was obtained by adjusting a simple linear regression model, independently from the treatment (diets) fixed effects and Latin squares. For both the sheep and goats, a complete recovery of the iDM and iNDF markers was observed (p>0.05), indicating the absence of LTB for these markers. However, the iADF was not completely recovered, exhibiting an LTB of -9.12% (p<0.05) in the sheep evaluation and -3.02% (p<0.05) in the goat evaluation.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.4
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• pp.478-482
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• 2000

Whole cassava (Manihot esculenta, Crantz) crop was harvested about 10-15 cm above ground at 3 months after planting and sun dried for 1-3 days or until the leaves were crispy-dried and the branches and stems were mostly wilted to produce cassava hay. Cassava hay (CH) contained 86.3% DM, 8.9% ash, 23.6% CP, 44.3% NDF, 30.0% ADF, 5.8% ADL, 0.257% condensed tannin and 0.35 mg % HCN, respectively. In addition, CH contained relatively higher amino acid than alfalfa hay especially methionine, isoleucine, leucine and lysine. Ruminal fermentation of CH resulted in high concentrations of $C_2$, $C_3$, and $C_4$ at 72, 17 and 7 mol/100 mole, respectively. A feeding trial was conducted to study on effect of feeding of cassava hay in late lactating dairy cows fed on urea-treated rice straw during the dry season on their intake, ruminal pH, $NH_3$-N, milk yield and compositions. Thirty, Holstein-Friesian crossbred cows in their first lactation were randomly assigned in a randomized complete block design to receive five different dietary treatments: T1=supplementation of concentrate to milk yield at 1:2, T2=supplementation of concentrate to milk yield at 1:2+0.56 kg DM, T3=supplementation of concentrate to milk yield at 1:3+1.3 kg DM CH, T4=supplementation of concentrate to milk yield at 1:4+1.70 kg DM CH, T5=CH fed on ad libitum+small concentrate supplement. All cows received urea-treated rice straw as a roughage source throughout a 80 d feeding trial. The experiment revealed that cassava hay contained high level of protein and minimal level of tannin at 3 months of harvest. Tannin intake ranged from 1.44 to 13.36 g/hd/d and did not affect on urea-treated rice straw intake. Milk yield across treatments were similar (5.4-6.3 kg/hd/d) (p>0.05) but 3.5% FCM was highest in cows received CH at 1.70 kg/hd/d. Feeding of cassava hay resulted in increasing milk fat (4.0 to 4.6%) (p<0.05) and milk protein (3.8 to 5.3%) (p<0.05). Moreover, the use of CH could reduce concentrate supplementation to milk yield from 1:2 to 1:4, respectively, thus resulted in more milk income return.

• Animal Bioscience
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• v.34 no.1
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• pp.74-84
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• 2021

Objective: Feed additives that modify rumen fermentation can be used to prevent metabolic disturbances such as acidosis and optimize beef cattle production. The study evaluated the effects of liquid and powdered forms of polyclonal antibody preparation (PAP) against Streptococcus bovis and Fusobacterium necrophorum on rumen fermentation parameters in ruminally cannulated non-lactating dairy cows that were adapted or unadapted to a high concentrate diet. Methods: A double 3×3 Latin square design was used with three PAP treatments (control, powdered, and liquid PAP) and two adaptation protocols (adapted, unadapted; applied to the square). Adapted animals were transitioned for 2 weeks from an all-forage to an 80% concentrate diet, while unadapted animals were switched abruptly. Results: Interactions between sampling time and adaptation were observed; 12 h after feeding, the adapted group had lower ruminal pH and greater total short chain fatty acid concentrations than the unadapted group, while the opposite was observed after 24 h. Acetate:propionate ratio, molar proportion of butyrate and ammonia nitrogen concentration were generally greater in adapted than unadapted cattle up to 36 h after feeding. Adaptation promoted 3.5 times the number of Entodinium protozoa but copy numbers of Streptococcus bovis and Fibrobacter succinogens genes in rumen fluid were not affected. However, neither liquid nor powdered forms of PAP altered rumen acidosis variables in adapted or unadapted animals. Conclusion: Adaptation of cattle to highly fermentable carbohydrate diets promoted a more stable ruminal environment, but PAP was not effective in this study in which no animal experienced acute or sub-acute rumen acidosis.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.657-666
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• 2007

This study was conducted to evaluate the effects of dietary addition of caprylic acid(CA)-cyclodextrin (CD) complex on in vitro fermentation characteristics, total gas and methane production. Experiment was done with six treatment groups; 1) no CA-CD complex(control), 2) CA 20 mg(T1), 3) CD 830 mg(T2), 4) CA-CD complex 425 mg(T3), CA-CD complex 850mg(T4), CA-CD complex 1,700 mg(T5). Ruminal pH, ammonia and total VFA concentrations of T2, T3, T4 and T5 were lower(P<0.05) than those of control and T1 for the 12h incubation. The increase in molar percentage of propionate was observed in T4 and T5 compared with control and T2 for the 8h incubation(P<0.05), however, the ratio of acetate to propionate was unchanged in all treatments. Total gas of T1 was lower than that of control, but T2, T3, T4 and T5 were higher compared with control for 12h incubation(P<0.05). If the methane ratio (as %) to total gas for all treatments was compared, T3, T4 and T5(CA-CD supplemented groups) averaged 2.7% whereas control, T1 and T2 showed 3.4, 2.8 and 5.1%, respectively. Therefore, according to these results, it might be concluded that supplementation of CA-CD complex could reduce methane production without disrupting ruminal fermentation.