• 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.

• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.200-209
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• 2011

Animals produce important co-products such as meat, milk, and egg. Higher consumption and urbanization asked for more animal products and the demand was so strong that lager livestocks are now being raised densely in small farm. Large production of excreta and maldor is an inevitable consequence of condensed breeding. If this malodor couldn't be controlled, it could be chief obstacle to development of both livestock industry and environment of future. Major odor produced from livestock environments could be subdivided into four major sections: volatile fatty acids, ammonia and volatile amine, indole and phenols, and sulfur compounds. More than half of nitrogen excreted urea, so low protein feeding, synthetic amino acid feeding and supplementing with digestive enzyme, microbial agents and/or probiotics are methods for reducing nitrogen excretion. A lot of studies about feeding and probiotics, co-feed have been researched to improve environment and/or productivity in livestock industry.

• Fisheries and Aquatic Sciences
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• v.24 no.2
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• pp.99-107
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• 2021

Water temperature (WT) is a major environmental factor of metabolic rate in fish; it directly affects food intake, ammonia excretion, oxygen consumption (OC), growth, and survival. Thus, the purpose of this study was to investigate changes in the OC and the hematological response of olive flounder Paralichthys olivaceus because of WT changes. In Exp. I, WT was increased from 20℃ to 29℃ within 18 h and maintained at 29℃ for 96 h. Then, WT was decreased from 29℃ to 20℃ within 18 h and maintained at 20℃ for 24 h. In Exp. II, WT was decreased from 20℃ to 11℃ within 18 h and maintained at 11℃ for 96 h. Then, WT was increased from 11℃ to 20℃ within 18 h and maintained at 20℃ for 24 h. The Exp. III maintained that the Exp. I and II was consecutively. In Exp. I, the OC increased from 116.7 mg O₂ kg^-1 hr^-1 to 317.5 mg O₂ kg^-1 hr^-1 with increasing WT. In Exp. II, the OC decreased from 96.5 mg O₂ kg^-1 hr^-1 to 71.3 mg O₂ kg^-1 hr^-1 with decreasing WT. In Exp. III, OC tended to increase or decrease in inverse proportion to temperature. In Exp. I, cortisol, glucose, and aspartate aminotransferase (AST) values increased with increasing WT. In Exp. II, Cl^-, osmolality, AST, and alanine aminotransferase (ALT) values significantly changed during the experimental period: glucose values increased, whereas cortisol values decreased with decreasing WT. Exp. III was shown to be a more stressful environment to olive flounder than Exp. I and Exp. II. The results of our study will be useful for evaluating current aquaculture procedures of olive flounder and developing techniques to minimize stress in aquaculture farms.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.1
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• pp.46-54
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• 2014

This study was conducted to investigate the effects of eucalyptus (E. Camaldulensis) crude oils (EuO) supplementation on voluntary feed intake and rumen fermentation characteristics in swamp buffaloes. Four rumen fistulated swamp buffaloes, body weight (BW) of $420{\pm}15.0$ kg, were randomly assigned according to a $2{\times}2$ factorial arrangement in a $4{\times}4$ Latin square design. The dietary treatments were untreated rice straw (RS) without EuO (T1) and with EuO (T2) supplementation, and 3% urea-treated rice straw (UTRS) without EuO (T3) and with EuO (T4) supplementation. The EuO was supplemented at 2 mL/h/d in respective treatment. Experimental animals were kept in individual pens and concentrate mixture was offered at 3 g/kg BW while roughage was fed ad libitum. Total dry matter and roughage intake, and apparent digestibilites of organic matter and neutral detergent fiber were improved (p<0.01) by UTRS. There was no effect of EuO supplementation on feed intake and nutrient digestibility. Ruminal pH and temperature were not (p>0.05) affected by either roughage sources or EuO supplementation. However, buffaloes fed UTRS had higher ruminal ammonia nitrogen and blood urea nitrogen as compared with RS. Total volatile fatty acid and butyrate proportion were similar among treatments, whereas acetate was decreased and propionate molar proportion was increased by EuO supplementation. Feeding UTRS resulted in lower acetate and higher propionate concentration compared to RS. Moreover, supplementation of EuO reduced methane production especially in UTRS treatment. Protozoa populations were reduced by EuO supplementation while fungi zoospores remained the same. Total, amylolytic and cellulolytic bacterial populations were increased (p<0.01) by UTRS; However, EuO supplementation did not affect viable bacteria. Nitrogen intake and in feces were found higher in buffaloes fed UTRS. A positive nitrogen balance (absorption and retention) was in buffaloes fed UTRS. Supplementation of EuO did not affect nitrogen utilization. Both allantoin excretion and absorption and microbial nitrogen supply were increased by UTRS whereas efficiency of microbial protein synthesis was similar in all treatments. Findings of present study suggested that EuO could be used as a feed additive to modify the rumen fermentation in reducing methane production both in RS and UTRS. Feeding UTRS could improve feed intake and efficiency of rumen fermentation in swamp buffaloes. However, more research is warranted to determine the effect of EuO supplementation in production animals.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.8
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• pp.1111-1119
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• 2016

Mao seed is a by-product of the wine and juice industry, which could be used in animal nutrition. The current study was designed to determine the effect of supplementation of mao (Antidesma thwaitesianum Muell. Arg.) seed meal (MOSM) containing condensed tannins (CT) on rumen fermentation, nitrogen (N) utilization and microbial protein synthesis in goats. Four crossbred (Thai Native${\times}$Anglo Nubian) goats with initial body weight (BW) $20{\pm}2kg$ were randomly assigned to a $4{\times}4$ Latin square design. The four dietary treatments were MOSM supplementation at 0%, 0.8%, 1.6%, and 2.4% of total dry matter (DM) intake, respectively. During the experimental periods, all goats were fed a diet containing roughage to concentrate ratio of 60:40 at 3.0% BW/d and pangola grass hay was used as a roughage source. Results showed that supplementation with MOSM did not affect feed intake, nutrient intakes and apparent nutrient digestibility (p>0.05). In addition, ruminal pH and ammonia nitrogen ($NH_3$-N) were not influenced by MOSM supplementation, whilst blood urea nitrogen was decreased quadraticly (p<0.05) in goats supplemented with MOSM at 2.4% of total DM intake. Propionate was increased linearly with MOSM supplementation, whereas acetate and butyrate were remained the same. Moreover, estimated ruminal methane ($CH_4$) was decreased linearly (p<0.05) when goats were fed with MOSM at 1.6% and 2.4% of total DM intake. Numbers of bacteria and protozoa were similar among treatments (p>0.05). There were linear decreases in urinary N (p<0.01) and total N excretion (p<0.01) by MOSM supplementation. Furthermore, N retention was increased linearly (p<0.05) when goats were fed with MOSM supplementation at 1.6% and 2.4% of total DM intake. Microbial protein synthesis were not significantly different among treatments (p>0.05). From the current study, it can be concluded that supplementation of MOSM at 1.6% to 2.4% of total DM intake can be used to modify ruminal fermentation, especially propionate and N utilization in goats, without affecting the nutrient digestibility, microbial populations and microbial protein synthesis.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.11
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• pp.1455-1461
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• 2010

Three rumen-cannulated Holstein steers were fed three diets, each with a different synchrony index (SI) (LS: 0.77, MS: 0.81, and HS: 0.83), in order to examine the effect of diet on rumen fermentation, nitrogen balance, and microbial protein synthesis. Synchrony index was calculated based on the carbohydrate and crude protein fractions of each ingredient and their degradation rates. Feeding the steers diets with different SIs did not influence dry matter, crude protein, NDF, or ADF digestibility. The concentrations of total and individual VFA in the rumens of steers that were fed the two higher-SI diets were higher than in those fed the low-SI diet (p<0.05), but there was no significant difference between the two higher-SI diets. One hour after feeding, steers on the LS diet had lower ruminal pHs than did those fed the MS or HS diets (p<0.05), and animals on the LS diet generally showed higher ruminal $NH_3$-N levels than did animals on the other diets, with the 4-h post-feeding difference being significant (p<0.05). Steers receiving the LS diet excreted more nitrogen (N) in their urine than did those on the two higher-SI diets (p<0.05), and the total N excretion of those on the LS diet was also higher (p<0.05). Microbial N levels calculated from the concentration of urinary purine derivatives were generally higher when the SI was higher, with the highest microbial protein synthesis being produced by steers on the HS diet (p<0.05). In conclusion, in the current study, ingestion of a synchronous diet by Holstein steers improved microbial protein synthesis and VFA production and decreased total N output.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.3
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• pp.351-359
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• 2015

Twelve multiparous Holstein dairy cows in mid-lactation were selected for a replicated $4{\times}4$ Latin square design with a $2{\times}2$ factorial arrangement to investigate the effects of corn and soybean meal (SBM) types on rumen fermentation, N metabolism and lactation performance in dairy cows. Two types of corn (dry ground [DGC] and steam-flaked corn [SFC]) and two types of SBM (solvent-extracted and heat-treated SBM) with different ruminal degradation rates and extents were used to formulate four diets with the same basal ingredients. Each period lasted for 21 days, including 14 d for adaptation and 7 d for sample collection. Cows receiving SFC had a lower dry matter (DM) and total N intake than those fed DGC. However, the milk yield and milk protein yield were not influenced by the corn type, resulting in higher feed and N utilization efficiency in SFC-fed cows than those receiving DGC. Ruminal acetate concentrations was greater and total volatile fatty acids concentrations tended to be greater for cows receiving DGC relative to cows fed SFC, but milk fat content was not influenced by corn type. The SFC-fed cows had lower ruminal ammonia-N, less urea N in their blood and milk, and lower fecal N excretion than those on DGC. Compared with solvent-extracted SBM-fed cows, cows receiving heat-treated SBM had lower microbial protein yield in the rumen, but similar total tract apparent nutrient digestibility, N metabolism measurements, and productivity. Excessive supply of metabolizable protein in all diets may have caused the lack of difference in lactation performance between SBM types. Results of the present study indicated that increasing the energy degradability in the rumen could improve feed efficiency, and reduce environmental pollution.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.4
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• pp.479-484
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• 2001

The effect of dietary supplementation of sodium salt of isobutyric acid in low protein (10% CP) wheat straw based diet on nutrient utilization and rumen fermentation was studied in ruminally fistulated male crossbred cattle. The study included a 7 day metabolism and a 3 day rumen fermentation trials. The cattle were distributed into two equal groups of 4 each. The animals of control group were fed a basal diet consisting of wheat straw, concentrate mixture and green maize fodder in 40:40:20 proportion whereas branched chain volatile fatty acid (BCFA) supplemented group received a basal diet + isobutyric acid at 0.75 percent of basal diet. The duration of study was 36 days. The feed intake between experimental groups did not differ significantly and the average total DMI (% BW) was 2.01 and $2.28kg\;day^{-1}$ in control and BCFA supplemented diets. The dietary supplementation of BCFA improved (p<0.05) the DM, OM, NDF and cellulose digestibility by 4.46, 6.63, 10.57 and 11.31 per cent over those fed control diet. The total N retention on BCFA supplementation was improved (p<0.01) due to decreased (p<0.05) urinary N excretion. The concentrations of ruminal total N was 37.07 and $34.77mg\;100ml^{-1}$ in control and BCFA fed groups, respectively. Dietary supplementation BCFA significantly (p<0.01) reduced the ruminal ammonia N concentration as compared to control and the mean values ($mg\;100ml^{-1}$) were 13.18 and 9.42 in control and BCFA fed groups. The total VFA concentration was higher (p<0.01) in BCFA supplemented group (101.14 mM) than the control (93.05 mM). Among the VFAs, the molar proportion of acetate was higher (p<0.01) in BCFA supplemented group (71.07 mM) as compared to control (64.98 mM). However, the concentration of propionate and butyrate remained unchanged. Amino acids composition of bacterial hydrolysates was similar in both the groups. Ruminal outflow rate of liquid digesta was higher (p<0.01) in BCFA fed group ($67.56l\;day^{-1}$) than control ($52.73l\;day^{-1}$). It is concluded that the dietary supplementation of Na-salt of isobutyric acid in low protein diet improved the nutrient utilization and ruminal fermentation characteristics.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.10
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• pp.1643-1653
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• 2018

Objective: This study investigated the effect of dietary crude protein (CP) supplementation on nutrient intake, nitrogen (N) utilisation, blood metabolites, ruminal fermentation and growth performance of young Holstein bulls. Methods: Twenty-one young bulls weighing $277{\pm}11.2kg$ were equally divided into three groups and were offered diets formulated with low CP (LCP; 10.21% CP and 4.22% rumen degradable protein [RDP]), medium CP (MCP; 12.35% CP and 5.17% RDP) and high CP (HCP; 14.24% CP and 6.03% RDP). Yellow corn silage was used as a unique forage source and was mixed with concentrate. This mixed feed was given ad libitum to the young bulls included in the study. Results: Results showed that CP intake, blood urea nitrogen, N intake, total N excretion and N balance increased linearly with an increase in dietary CP level (p<0.05). However, no significant difference was observed in nutrient digestibility among the bulls receiving the different diets. Ruminal pH (p<0.05) and ammonia nitrogen ($NH_3-N$) concentration (p<0.01) were significantly higher in the bulls receiving the MCP and HCP diets than in those receiving the LCP diet. The bulls receiving the HCP diet showed significantly higher ruminal bacterial protein level, propionate, acetate and total volatile fatty acid (TVFA) concentrations than bulls receiving the LCP diet (p<0.05). Moreover, dietary CP level exerted a significant positive effect on the final body weight, average daily gain and gain-to-feed ratio of the bulls (p<0.05). Conclusion: High dietary CP level is optimal for achieving maximum growth and high profitability without exerting a negative effect on the physiology of growing Holstein bulls.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.4
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• pp.497-503
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• 2004

The effect of adding carbohydrate-rich feedstuffs to sweet potato leaves (SPL) on silage quality was studied using a total of 180 laboratory silos. Silage quality was assessed by changes of pH, dry matter (DM), crude protein (CP) and ammonia nitrogen ($NH_{3}$-N). Pre-wilted SPL was mixed with cassava root meal (CRM), sweet potato root meal (SPM) or sugar cane molasses (Mo) at levels of 0, 30, 60 and 90 g $kg^{-1}$ (air-dry weight of additives to pre-wilted weight of SPL). Samples for assessing silage quality were collected after mixing the SPL with the additive and thereafter at 7, 14, 28 and 56 days of ensiling. There was a marked decrease in pH after 7 days and the pH remained low and stable until day 56. Addition of 60 and 90 g $kg^{-1}$ resulted in a lower pH (p<0.05) than the other treatments. The DM content of the silage increased (p<0.05) with increasing levels of additive, while there were no differences in DM with time of ensiling. The CP content of the silage decreased (p<0.05) with increasing levels of additive. The CP content did not change up to 28 days, but was lower (p<0.05) after 56 days in all treatments. The $NH_{3}$-N levels were increasing (p<0.05) with time of ensiling, and were lower (p<0.05) with additive levels of 60 g $kg^{-1}$ or higher. Also, the additive source affected the $NH_{3}$-N values, with the lowest values found for Mo. Castrated male pigs (Large White$\times$Mongcai) were used in 4$\times$4 Latin square design to study the total tract digestibility and nitrogen (N) utilisation of diets with inclusion of ensiled SPL. The diets were based on cassava root meal with inclusion of protein from either fish meal (C) or SPL ensiled with CRM (D1), SPL ensiled with SPM (D2) and SPL ensiled with Mo (D3). The digestibility of DM, organic matter (OM) and CP were higher (p<0.05), and the digestibility of crude fibre (CF) was lower (p<0.05), in diet C than in diets D1, D2 and D3. However, there were no differences (p>0.05) in digestibility of dietary components between diets D1, D2 and D3. Also, the excretion of N in faeces was higher (p<0.05) and the N retention was lower (p<0.05) in diets D1, D2 and D3 than in diet C. It can be concluded from the present experiments, that a good quality silage can be produced from pre-wilted SPL by addition of 60 g $kg^{-1}$ of either CRM, SPM or Mo. Diets with inclusion of 450 g ensiled SPL $kg^{-1}$ DM showed a high digestibility of dietary components and thus ensiled SPL should be considered as a potential feed resource for growing pigs.