• Asian-Australasian Journal of Animal Sciences
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• v.3 no.3
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• pp.225-229
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• 1990

Sixteen mature sheep were fed chaffed orchardgrass hay once a day. Jaw movement of the sheep was recorded for 24 hours before slaughter. Four sheep were slaughtered either prior to eating, 2, 8 or 16 hours after the commencement of eating to measure digesta pool size and particle size distribution in the reticulo-rumen. Eating time was restricted to 120 minutes. Rumination time and actual chewing time during rumination increased with time after the meal. Mean dry matter (DM) pool size before and 2 hours after the meal were 1.36 and 2.45 times of DM intake, respectively. The proportion of large particle (>1.18 mm; LP) in the DM ingested during the meal was caculated to be about 70%. The mean DM and LP pool sizes per DM intake and the mean proportion of LP in the DM pool decreased with time after the meal. There were close negative relationships between either DM or LP pool sizes per DM intake and the chewing activities either expressed as time spent rumination, actual chewing time during rumination or total actual chewing time(total of eating time and actual chewing time during rumination). The difference between DM intake and LP pool size were assumed to be LP degradation in the present experiment, and correlated positively with the chewing activities. A large proportion of the digesta load was comprised of small particles, in excess of the daily intake.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.379-386
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• 2016

Four ruminally cannulated Holstein steers (BW $482.9{\pm}8.10kg$), fed low protein TMR (CP 11.7%) as a basal diet, were used to investigate changes in rumen fermentation and blood metabolism according to protein fraction, cornell net carbohydrates and protein system (CNCPS), and enriched feeds. The steers, arranged in a $4{\times}4$ Latin square design, consumed TMR only (control), TMR supplemented with rapeseed meal (AB1), soybean meal (B2), and perilla meal (B3C), respectively. The protein feeds were substituted for 23.0% of CP in TMR. Ruminal pH, ammonia-N, and volatile fatty acids (VFA) in rumen digesta, sampled through ruminal cannula at 1 h-interval after the morning feeding, were analyzed. For plasma metabolites analysis, blood was sampled via the jugular vein after the rumen digesta sampling. Different N fraction-enriched protein feeds did not affect (p > 0.05) mean ruminal pH except AB1 being numerically lower 1 - 3 h post-feeding than the other groups. Mean ammonia-N was statistically (p < 0.05) higher for AB1 than for the other groups, but VFA did not differ among the groups. Blood urea nitrogen was statistically (p < 0.05) higher for B2 than for the other groups, which was rather unclear due to relatively low ruminal ammonia-N. This indicates that additional studies on relationships between dietary N fractions and ruminant metabolism according to different levels of CP in a basal diet should be required.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.4
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• pp.617-622
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• 1992

Four rumen-fistulated swamp buffaloes steers were used in a change-over experiment. This experiment was designed to provide a comparison of the effect of urea-ammonia treatment of rice straw with untreated rice straw. Nitrogen, mineral and trace elements were supplied at adequate levels to both diets in order to overcome deficiencies which may have otherwise confounded a direct comparison. There was a 46% increase in the intake of digestible organic matter (OM) with the urea-ammonia treated diet. This was contributed by a 17% increase in the digestibility of OM and a 25% increase in the voluntary intake of OM. Of the cell wall fraction, the digestibility of hemicellulose increased by the greatest amount (26%). There was an increased rate of passage of particulate matter out of the rumen for the treated straw, along with the increased rate of OM fermentation resulted in a 9% decrease in the amount of digesta dry matter (DM) contained in the rumen. The volatile fatty acid (VFA) pool in the rumen was 24% higher for the treated diet.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.317-318
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.411-412
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.55-61
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• 1992

To determine the effect of time after feeding on distribution of particle size of digesta in the gastrointestinal tract, 16 sheep given orchardgrass first cut hay were slaughtered at 2, 8, 16 and 24 hours after feeding and digesta in diverse sites of the tract were sieved into four fractions of particle size larger than $1180{\mu}m$, 300-1180, 45-300 and less than 45. Following results were obtained: 1) In the reticulo-rumen, the proportion of particles larger than $1180{\mu}m$ decreased with the time after feeding, while the other particle size fractions did not change with time after feeding. 2) In the post-ruminal alimentary tract, the proportion of particles larger than $1180{\mu}m$ was significantly smaller than that in the reticulo-rumen and distribution of fractions of every particle size stayed consistently at about the same level irrespective of the time after feeding. 3) In the cecum, the fraction of particle size less than $45{\mu}m$ appeared to be selectively retained when the passage rate was considered.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.1
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• pp.113-128
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• 1999

Protozoa can represent as half of the total rumen microbial biomass. Around 10 genera are generally present on the same time in the rumen. Based on nutritional aspects they can be divided in large entodiniomorphs, small entodiniomorphs and isotrichs. Their feeding behaviour and their enzymatic activities differ considerably. Many comparisons between defaunated and refaunated animals were carried out during the last two decades to explain the global role of protozoa at the ruminal or animal levels. It is now generally considered that a presence of an abundant protozoal population in the rumen has a negative effect on the amino acid (AA) supply to ruminants and contribute to generate more methane but, nevertheless, protozoa must not be considered as parasites. They are useful for numerous reasons. They stabilise rumen pH when animal are fed diets rich in available starch and decrease the redox potential of rumen digesta. Because cellulolytic bacteria are very sensitive to these two parameters, protozoa indirectly stimulate the bacterial cellulolytic activity and supply their own activity to the rumen microbial ecosystem. They could also supply some peptides in the rumen medium which can stimulate the growth of the rumen microbiota, but this aspect has never been considered in the past. Their high contribution to ammonia production has bad consequences on the urinary nitrogen excretion but means also that less dietary soluble nitrogen is necessary when protozoa are present. Changes in the molar percentages of VFA and gases from rumen fermentations are not so large that they could alter significantly the use of energy by animals. The answer of animals to elimination of protozoa (defaunation) depends on the balance between energy and protein needs of animals and the supply of nutrients supplied through the diet. Defaunation is useful in case of diets short in protein nitrogen but not limited in energy supply for animals having high needs of proteins.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.3
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• pp.267-273
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• 1995

The differences in rumen particle pool size, passage rate and rumen degradability in sheep receiving three varieties of orchardgrass hay harvested at pre-heading (H1), early-bloom (H2) and late-bloom (H3) were investigated using four ruminal-cannulated wethers (68 kg) fed 1,300 g of the hay once a day. Representative samples of whole rumen contents were collected at different times after feeding and the quantities of rumen particle pools [large particle pool (LPP), retained on a $1,180{\mu}m$ sieve; small particle pool (SPP), retained on a 47 but passed a $1,180{\mu}m$ sieve; and soluble fraction (SOL), passed a $47{\mu}m$ sieve (SOL)] were determined by a wet-sieving technique. The fullowing results were obtained: 1) The dry weight of whole rumen contents were significantly lower (p < 0.05) for HI than for H2 or H3. The reduction rate of whole rumen contents was slightly but significantly greater for HI that, the other hay varieties. 2) The LPP disappearance rates were 26.2, 25.3 and 21.7 g DM/h for H1, H2 and H3, respectively, and no statistical differences were found among the hay varieties. Appreciable changes were not observed with SPP and SOL throughout measurements for all hay varieties; however the SPP was markedly greater (p <0.05) for H2 and ill than for HI, while SOL did not differ among hay varieties. 3) The SPP passage rate (g DM/h) and effective rumen degradability (%) for HI, H2 and ill were, respectively, 9.7, 56.6; 16.9, 42.3; and 18.0, 28.9. The ruminal tum-over rate for SPP appeared to be higher for HI than for the other hay varieties.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.1
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• pp.137-145
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• 1994

Amino acid (AA) substituted diets had no influence on rumen levels of total volatile fatty acids (VFA), ammonia and ${\alpha}$-amino-N, but tended to increase molar proportions of isovalerate and counts of total viable AA utilizing and celluloytic bacteria in the rumen as compared with the control urea diet. The AA diets did not affect daily flow to the duodenum of dry matter (DM), organic mater (OM) and acid detergent fibre (ADF), and rumen digestibility of these nutrients. However, the AA diets, in particular the 10 essential AA (EAA) diet improved total digestibility of DM, OM and ADF by decreasing faecal output of these fractions. Although N flow to the duodenum and N retention were not affected with the dietary treatments, duodenal bacterial flow appeared to increase by the AA diets when it was estimated by means of 2,6-diaminopimelic acid (DAP) and nucleic acid-purine bases (PB) as markers. The results suggest that AA supplements to a urea diet could improve feed utilization by stimulating microbial activity and proliferation in the rumen but and increased microbial activity per se is not necessarily associated with improvement of feed conversion.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.19-24
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• 1992

Formula feed for fattening cattle ground through 2 mm screen was incubated in the rumen of sheep and goats to evaluate effects of ratio of concentrate to hay and kinds of hay in a ration on determining the degradability (dg) value of protein using in sacco technique. Following results were obtained: 1) Residual dry matter (DM) and crude protein (CP) of formula feed decreased as the time of incubation increased. Regression analyses showed that rates of degradation of DM and CP in the rumen were not the same when they were determined under feeding of rations with different percentages of concentrate. 2) Rate of passage of digesta from the rumen differed between feeding of Italian ryegrass hay ration and that of alfalfa hay ration, but was not influenced by the percentage of concentrate in a ration. 3) The dg value was different when it was estimated with results obtained from determinations under feeding of Italian ryegrass hay ration or that of alfalfa hay ration. The percentage of concentrate in a ration had no influence on the dg value of protein in formula feed.