• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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• pp.181-188
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• 2006

The objective of this research was to determine the effects of synchronizing the rate of dietary energy and nitrogen release on: ruminal fermentation, microbial protein synthesis, blood urea nitrogen, and nutrient digestibility in beef cattle. Four, two-and-a-half year old Brahman-Thai native crossbred steers were selected for the project. Each steer was fitted with a rumen cannula and proximal duodenal cannula. The steers were then randomly assigned in a $4{\times}4$ Latin square design to receive four dietary treatments. Prior to formulation of the dietary treatments, feed ingredients were analyzed for chemical composition and a nylon bag technique was used to analyze the treatments various ingredients for degradability. The treatments were organized in four levels of a synchrony index (0.39, 0.50, 0.62 and 0.74). The results showed that dry matter digestibility trend to be increased (p<0.06), organic matter and acid detergent fiber digestibility increased linearly (p<0.05), while crude protein and neutral detergent fiber digestibility were not significantly different (p>0.05). Higher concentration and fluctuation of ruminal ammonia and blood urea were observed in the animal that received the lower synchrony index diets. As the levels of the synchrony index increased, the concentrations of ruminal ammonia nitrogen and blood urea nitrogen, at the 4 h post feeding, decreased linearly (p<0.05). Total volatile fatty acid and bacteria populations at the 4 h post feeding increased linearly (p<0.05). Microbial protein synthesis trend to be increase (p<0.08). The results of this research indicate that synchronizing the rate of degradation of dietary energy and nitrogen release improves ruminal fermentation, microbial protein synthesis and feed utilization.

• Journal of Veterinary Science
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• v.24 no.2
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• pp.27.1-27.15
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• 2023

Background: The relationships between the postpartum subacute ruminal acidosis (SARA) occurrence and predicted bacterial functions during the periparturient period are still not clear in Holstein cows. Objectives: The present study was performed to investigate the alterations of rumen fermentation, bacterial community structure, and predicted bacterial functional pathways in Holstein cows. Methods: Holstein cows were divided into the SARA (n = 6) or non-SARA (n = 4) groups, depending on whether they developed SARA during the first 2 weeks after parturition. Reticulo-ruminal pH was measured continuously during the study period. Reticulo-ruminal fluid samples were collected 3 weeks prepartum, and 2 and 6 weeks postpartum, and blood samples were collected 3 weeks before, 0, 2, 4 and 6 weeks postpartum. Results: The postpartum decline in 7-day mean reticulo-ruminal pH was more severe and longer-lasting in the SARA group compared with the non-SARA group. Changes in predicted functional pathways were identified in the SARA group. A significant upregulation of pathway "PWY-6383" associated with Mycobacteriaceae species was identified at 3 weeks after parturition in the SARA group. Significantly identified pathways involved in denitrification (DENITRIFICATION-PWY and PWY-7084), detoxification of reactive oxygen and nitrogen species (PWY1G-0), and starch degradation (PWY-622) in the SARA group were downregulated. Conclusions: The postpartum SARA occurrence is likely related to the predicted functions of rumen bacterial community rather than the alterations of rumen fermentation or fluid bacterial community structure. Therefore, our result suggests the underlying mechanisms, namely functional adaptation of bacterial community, causing postpartum SARA in Holstein cows during the periparturient period.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.10
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• pp.1395-1403
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• 2012

The objective of the study was to quantify annual and seasonal differences in the chemical composition, in vitro gas production, in situ degradability and ruminal fermentation of grazing steers… diets. Diet samples were collected with four esophageal cannulated steers ($350{\pm}3$ kg BW); and four ruminally cannulated heifers ($342{\pm}1.5$ kg BW) were used to study the dry matter degradation and fermentation in rumen. Data were analyzed with repeated measurements split plot design. The crude protein, in vitro dry matter digestibility and metabolizable energy were higher during the first year of trial and in the summer (p<0.01). The values of calcium, phosphorus, magnesium, zinc and copper were higher in summer (p<0.05). The gas produced by the soluble and insoluble fractions, as well as the constant rate of gas production were greater in summer and fall (p<0.01). The ammonia nitrogen ($NH_3N$) and total volatile fatty acids concentrations in rumen, the soluble and degradable fractions, the constant rate of degradation and the effective degradability of DM and NDF were affected by year (p<0.05) and season (p<0.01). Our study provides new and useful knowledge for the formulation of protein, energetic and mineral supplements that grazing cattle need to improve their productive and reproductive performance.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.7
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• pp.937-945
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• 2014

Green and black tea by-products, obtained from ready-made tea industry, were ensiled at $10^{\circ}C$, $20^{\circ}C$, and $30^{\circ}C$. Green tea by-product silage (GTS) and black tea by-product silage (BTS) were opened at 5, 10, 45 days after ensiling. Fermentation characteristics and nutrient composition, including tannins, were monitored and the silages on day 45 were subjected to in vitro ruminal fermentation to assess anti-nutritive effects of tannins using polyethylene glycol (PEG) as a tannin-binding agent. Results showed that the GTS and BTS silages were stable and fermented slightly when ensiled at $10^{\circ}C$. The GTS stored at $20^{\circ}C$ and $30^{\circ}C$ showed rapid pH decline and high acetic acid concentration. The BTS was fermented gradually with moderate change of pH and acid concentration. Acetic acid was the main acid product of fermentation in both GTS and BTS. The contents of total extractable phenolics and total extractable tannins in both silages were unaffected by storage temperatures, but condensed tannins in GTS were less when stored at high temperature. The GTS showed no PEG response on in vitro gas production, and revealed only a small increase by PEG on $NH_3$-N concentration. Storage temperature of GTS did not affect the extent of PEG response to both gas production and $NH_3$-N concentration. On the other hand, addition of PEG on BTS markedly increased both the gas production and $NH_3$-N concentration at any ensiled temperature. It can be concluded that tannins in both GTS and BTS suppressed rumen fermentation, and tannins in GTS did more weakly than that in BTS. Ensiling temperature for both tea by-products did not affect the tannin's activity in the rumen.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.2
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• pp.210-214
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• 1997

Ruminal degradation characteristics and intestinal availability of crude protein (CP) in four animal-origin feeds (fish meal, meat meal, viscera meal, feather meal) were estimated by mobile nylon bag technique. Three ruminally and duodenally cannulated Holstein dairy cows (average body wt. 550kg) fed a diet containing 40% concentrate and 60% orchard grass hay on a dry matter (DM) basis. Assuming that the outflow rate of diet in rumen is 5% per hour (k =0.05), contents of quickly degradable CP (QDP), slowly degradable CP (SDP), and undegradable CP (UDP) in the rumen were 27.6%, 9.4%, 63.0% for fish meal, 34.3% 28.1%, 37,6% for meat meal, 43.9%, 12.5%, 43.6% for viscera meal, and 14.4%, 15.8%, 69.8% for feather meal, respectively. Intestinal CP degradability was 51.0% for fish meal, 27.2% for meat meal, 37.9% for viscera meal and 56.2% for feather meal. Available UDP in the intestinal tract was contained 288 g, 217 g, 246 g and 423 g per kilogram DM of diet in fish meal, meat meal, viscera meal and feather meal, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.9
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• pp.1280-1284
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• 2003

The number of protozoa and VFA content in the rumen fluid, in situ disappearance and turnover rate were examined with four rumen-fistulated cattle given either sugarcane stalk or Ruzi grass hay in order to clarify the manner of rumen digestion of sugarcane stalk. Cattle were given either sugarcane stalk or Ruzi grass hay at 1.0% of body weight level with commercial concentrate feed. Feeding sugarcane stalk reduced acetate content and increased propionate and butyrate contents in rumen fluid. While rapidlysoluble fraction of sugarcane stalk was 42%, the insoluble but potentially degradable fraction was only 17%. This clearly showed that sugarcane stalk mainly consisted of water soluble fraction (i.e. sugar) and tough fiber (i.e. bagasse). The ruminal degradation rate of both Ruzi grass hay and sugarcane stalk was lower in the animal given sugarcane stalk in comparison with those given Ruzi grass hay. While the turnover rate of liquid phase was about 50% higher in the animals given sugarcane stalk than in the animals given Ruzi grass hay, that of the solid phase was about 40% lower in the animals given sugarcane stalk. The effective degradability of DM of sugarcane stalk was higher than that of Ruzi grass hay. Sugarcane would be a promising roughage for ruminants in the tropics especially, in the dry season.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.3
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• pp.389-393
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• 2003

Present study investigate the effect of enzyme supplementation, methods (applied to rumen or enzyme treated diet) compared with no enzyme diet, on rumen fermentation and apparent nutrient digestibility in a $3{\times}3$ Latin square design with three rumen cannulated Korean Native goats. In situ rumen degradation kinetics was studied in three rumen cannulated Holstein steers. Three diets were, no enzyme, 1% enzyme in rumen and 1% enzyme in diet. The enzyme was sprayed onto forage, and the forage: concentrate ratio was 30:70. Degradation kinetics was studied with three enzyme levels (0, 1 and 2%, w/w) and four pre-treatment times (0, 1, 12 and 24 h). Results suggested that enzyme application method did not affect rumen fermentation, ruminal enzyme activity and total tract apparent digestibility. Nutrient degradation rate and effective degradability of DM, NDF and ADF increased with increasing enzyme level and pre-treatment times. Degradation of nutrients was affected by enzymes levels or pre-treatment times. Therefore, it is probable that the improved degradation may be due to the supplemented exogenous hydrolytic enzymes under a certain condition.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.6
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• pp.541-550
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• 1997

Anaerobic chytridiomycete fungi are now well recognized as one of the major components of rumen microflora. Since the discovery of anaerobic fungi, the knowledge upon their morphology and physiology has been accumulated. It is certain that they gave roles in ruminal fiber digestion, although their quantitative contribution to rumen digestion is still unclear. Their role in fiber digestion is complicated by the dietary factors and the interaction with other microorganisms. We aim at reviewing such information in this article. Considerable attention gas been paid to the polysaccharidase of these fungi. Analysis on the fungal genes encoding these enzymes has been performed in several laboratories. This article also covers the genetical analysis of fungal polysaccharidases.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.887-893
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• 2007

Influences of forage DM and addition of cane molasses on silage characteristics of berseem (Trifolium alexandrium) and lucerne (Medicago sativa) and their ruminal digestion kinetics in Nili buffaloes were studied. Berseem and lucerne fodders (at one tenth bloom) were ensiled with wheat straw in laboratory silos to achieve 20, 30, 40% forage DM and without wheat straw (control); each forage DM level was supplemented with 2, 4 and 6% of cane molasses at ensiling. The pH and lactic acid contents of berseem and lucerne silages were affected by both forage DM and addition of molasses. Dry matter, CP and true protein (TP) of berseem and lucerne silages were affected by forage DM at ensiling but were not affected by the addition of cane molasses. Higher DM, CP and TP losses were observed when berseem and lucerne fodders were ensiled either without wheat straw or with wheat straw to achieve 20% and 40% forage DM at ensiling compared with 30% DM at ensiling. Fiber fractions (NDF, ADF, hemicellulose and cellulose) of berseem silage and lucerne silage were significantly increased with increasing forage DM at ensiling. Addition of cane molasses did not affect the DM, CP, TP and fiber fractions of both berseem and lucerne silages. Berseem and lucerne ensiled at 30% DM with 2% cane molasses were screened for comparative ruminal digestion kinetics with their respective fodders. Addition of wheat straw to berseem or lucerne fodder at ensiling depressed DM and NDF ruminal degradability. However, ruminal lag time, rate of degradation and extent of digestion of silages were similar to their respective fodders. In conclusion, berseem and lucerne could be ensiled with wheat straw to increase their DM to 30% along with 2% molasses for buffaloes.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.8
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• pp.1205-1214
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• 1999

Whole lupinus albus seeds were pressure toasted at temperatures of 100, 118 and $136^{\circ}C$ for 3, 7, 15 and 30 min to study rumen degradation and post-rumen digestion and to determine optimal heating conditions for the Dutch dairy feed industry. In sacco nylon bag and mobile bag techniques were employed for rumen and intestine incubations to determine ruminal degradation characteristics and intestinal digestion of crude protein (CP) in 4 lactation rumen cannulated and 4 lactating intestinal cannulated Dutch dairy cows fed 47% hay and 53% concentrate according to Dutch dairy requirements. Measured rumen degradation characteristics were soluble fraction (S), undegradable fraction (U), potentially degradable fraction (D), lag time (T0) and rate of degradation (Kd) of insoluble but degradable fraction. Percentage bypass feed protein (BCP), ruminal microbial protein synthesized based on available nitrogen (N_MP) and that based on available energy (E_MP), true protein supplied to the small intestine (TPSI), truly absorbed BCP (ABCP), absorbed microbial protein (AVP) in the small intestine, endogenous protein losses in the digestion (ENDP), true digested protein in the small intestine (TAP or DVE in Dutch) and degraded protein balance (PDB or OEB in Dutch) were totally evaluated using the new Dutch DVE/OEB System. Pressure toasting decreased (p<0.001) rumen degradability of CP. It reduced S (p<0.05) and Kd (p=0.06), increased D (p<0.05) and U (p<0.01) but did not alter T0 (p>0.05), thus resulting in dramatically increased BCP (p<0.001) with increasing time and temperature from 73.7 (raw) up to 182.5 g/kg DM ($136^{\circ}C/15min$). Although rumen microbial protein synthesized based on available energy (E_MP) was reduced, true protein (microbial and bypass feed protein) supplied to the small intestine (TPSI) was increased (p<0.001) from 153.1 (raw) to 247.6 g/kg DM ($136^{\circ}C/15min$). Due to digestibility of BCP in the intestine not changing (p>0.05) average 87.8%, the absorbed BCP increased (p<0.001) from 62.3 (raw) to 153.7 g/kg DM ($136^{\circ}C/15min$). Therefore DVE value of true digested protein in the small intestine was significantly increased (p<0.001) from 118.9 (raw) to 197.0 g/kg DM ($136^{\circ}C/15min$) and OEB value of degraded protein balance was significantly reduced (p<0.001) from 147.2 (raw) to 63.1 g/kg DM ($136^{\circ}C/15min$). It was concluded that pressure toasting was effective in shifting degradation of CP of lupinus albus from the rumen to small intestine without changing intestinal digestion. Further studies are required on the degradation and digestion of individual amino acids and on the damaging effects of processing on amino acids, especially the first limiting amino acids.