• Asian-Australasian Journal of Animal Sciences
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• 제22권5호
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• pp.651-658
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• 2009

Four multiparous lactating Holstein cows fitted with rumen cannulae were fed diets varying in the amount and source of rumen-degradable carbohydrates (starch vs. sucrose) to examine their effects on rumen fermentation, nitrogen metabolism and lactation performance. A $4{\times}4$ Latin square with four diets and four periods of 28 days each was employed. Corn starch and sucrose were added to diets and corn starch was replaced with sucrose at 0 (0 S), 2.5 (2.5 S), 5.0 (5.0 S) 7.5% (7.5 S) of diet dry matter in a total mixed ration (TMR) containing 60% concentrate and 40% forage (DM basis). Replacing corn starch with sucrose did not affect (p>0.05) ruminal pH which averaged 6.41, but the ruminal pH for 7.5 S decreased more rapidly at 2 h after morning feeding compared with other treatments. Sucrose reduced ($p{\leq}0.05$) ruminal $NH_3-N$ concentration (13.90 vs. 17.09 mg/dl) but did not affect peptide-N concentration. There was no dietary effect on total volatile fatty acids (110.53 mmol/L) or the acetate to propionate ratio (2.72). No differences (p>0.05) in molar proportion of most of the individual VFA were found among diets, except for the molar proportion of butyrate that was increased ($p{\leq}0.05$) with the inclusion of sucrose. Total branched chain volatile fatty acids tended to increase ($p{\geq}0.051$) for the control treatment (0 S) compared with the 7.5 S treatment. Dry matter intake, body weight changes and digestibility of DM, OM, CP, NDF and ADF were not affected by treatments. Sucrose inclusion in the total mixed ration did not affect milk yield, but increased milk fat and total solid percentage ($p{\leq}0.05$). Sucrose tended ($p{\geq}0.063$) to increase milk protein percentage (3.28 vs. 3.05) and reduced ($p{\leq}0.05$) milk urea nitrogen concentration (12.75 vs. 15.48 mg/dl), suggesting a more efficient utilization of the rapidly available nitrogen components in the diet and hence improving nitrogen metabolism in the rumen.

• Asian-Australasian Journal of Animal Sciences
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• 제31권5호
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• pp.677-685
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• 2018

Objective: The objective of the present study was to determine ammonium chloride tolerance of lactating dairy cows, by examining effects of negative dietary cation anion difference (DCAD) induced by ruminal ammonium chloride infusion on performance, serum and urine minerals, serum metabolites and enzymes of lactating dairy cows. Methods: Four primiparous lactating Chinese Holstein cows fitted with ruminal cannulas were infused with increasing amounts (0, 150, 300, or 450 g/d) of ammonium chloride in a crossover design. The DCAD of the base diet was 279 mEq/kg dry matter (DM) using the DCAD formula (Na + K - Cl - S)/kg of DM. Ammonium chloride infusion added the equivalent of 0, 128, 330, and 536 mEq/kg DM of Cl in treatments. According to the different dry matter intakes (DMI), the resulting actual DCAD of the four treatments was 279, 151, -51, and -257 mEq/kg DM, respectively. Results: DMI decreased linearly as DCAD decreased. Yields of milk, 4% fat-corrected milk, energy-corrected milk, milk fat, and milk protein decreased linearly as DCAD decreased. Concentrations of milk protein and milk urea nitrogen increased linearly with decreasing DCAD. Concentration of Cl- in serum increased linearly and concentration of PO43- in serum increased quadratically as DCAD decreased. Urine pH decreased linearly and calculated urine volume increased linearly with decreasing DCAD. Linear increases in daily urinary excretion of $Cl^-$, $Ca^{2+}$, $PO_4{^{3-}}$, urea N, and ammonium were observed as DCAD decreased. Activities of alanine aminotransferase, aspartate aminotransferase, and ${\gamma}-glutamyl$ transferase in serum and urea N concentration in serum increased linearly as DCAD decreased. Conclusion: In conclusion, negative DCAD induced by ruminal ammonium chloride infusion resulted in a metabolic acidosis, had a negative influence on performance, and increased serum enzymes indicating potential liver and kidney damage in lactating dairy cows. Daily ammonium chloride intake by lactating dairy cows should not exceed 300 g, and 150 g/d per cow may be better.

• 농업생명과학연구
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• 제51권4호
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• pp.97-109
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• 2017

본 시험은 항염에 효과가 있다고 알려진 식물 추출물의 첨가가 반추위 발효와 메탄 생성에 미치는 영향을 알아보기 위해 in vitro 실험을 수행하였다. 항염과 항산화 효과가 있는 산뽕나무, 뽕나무, 예덕나무, 오동나무, 방아풀과 은행나무 6종을 선발하였다. 반추위액과 McDougall buffer 혼합액 15mL과 티모시 0.3g, 각각의 추출물을 기질의 5%로 넣고 $39^{\circ}C$에서 3, 9, 12, 24, 48 그리고 72시간 배양하였다. 항염 효과가 있는 식물 추출물의 첨가는 반추위 발효 성상(pH, 건물소화율, Glucose 농도, 암모니아 농도, 단백질 농도, 미생물 성장량, 휘발성지방산)에는 영향을 미치지 않았다. 총 가스 발생량은 각기 다른 양상을 보였으며, 이산화탄소 발생량은 48시간대에서 예덕나무와 방아풀에서 대조구에 비해 유의적(p<0.05)으로 높았다. 또한 메탄 발생량은 배양 초기에는 대조구보다 첨가구에서 유의적(p<0.05)으로 감소하였으나, 발효가 진행될수록 대조구에 비해 첨가구에서 더 많은 메탄이 발생하였다. Polyphenol과 flavonoid는 은행나무 추출물구에서 가장 높았다. 본 시험의 결과에서 항염에 효과가 있는 식물 추출물을 in vitro 반추위 배양액에 첨가하였을 때, 반추위 발효에는 영향을 미치지 않았고, 메탄은 초기 발효에 저감 효과가 있는 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제21권12호
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• pp.1736-1744
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• 2008

Two experiments were conducted in central Vietnam to test the hypothesis that supplementation with a concentrate, comprising rice bran (45% fresh basis), maize (49%), fish meal (3%), urea (2%) and salt (1%), up to 2% of live weight (LW)/d (dry matter (DM) basis) would linearly increase digestible organic matter intake and LW gain of yellow cattle. In both experiments, there were five treatments, namely a basal diet of fresh grass fed at 1.25% of LW (experiment 1, elephant grass, Pennisetum purpureum; experiment 2, native grass) and rice straw (Oryza sativa) fed ad libitum or this diet supplemented with concentrate at about 0.3, 0.7, 1.3 or 2.0% LW. There were 4 male growing cattle per treatment in experiment 1 and 3 in experiment 2. Diets were fed for 44 (experiment 1) or 49 (experiment 2) days, with feed intake recorded daily, LW measured about weekly and digestibility measurements made over 7 days commencing on day 24 (experiment 1) or day 10 (experiment 2). The elephant grass and native grass had neutral detergent fibre (NDF) concentrations of 82 and 73% DM, and nitrogen concentrations of 1.3 and 1.8% DM, respectively. The rice straw used had a NDF concentration of 79-84% DM and nitrogen concentration of 0.8% DM. The concentrate had NDF and nitrogen concentrations of 33 and 2.8% DM. In both experiments, DM intake increased (p<0.001) linearly as the amount of concentrate consumed increased. Rice straw intake declined (p<0.001) (experiment 1: 1.24 to 0.48 kg DM/d; experiment 2: 0.95 to 0.50 kg DM/d) as concentrate intake increased. Grass intake was not significantly affected by concentrate intake in either experiment. The lowest amount of concentrate supplement increased forage intake, after which substitution rate increased as the amount of concentrate consumed increased. However, substitution rates at the highest amount of concentrate consumed were modest at 0.3 to 0.5 kg DM reduction in forage intake/kg DM supplement consumed. In both experiments, digestible organic matter intake increased linearly (p<0.001) (experiment 1: 1.16 to 2.38 kg/d; experiment 2: 1.30 to 2.49 kg/d) as the amount of supplement consumed increased, as did LW gain (experiment 1: 0.15 to 0.81 kg/d; experiment 2: 0.15 to 0.77 kg/d). This was associated with significant (p<0.01) linear increases in organic matter intake and apparent organic matter digestibility. Neutral detergent fibre digestibility declined as concentrate intake increased, but the effect was not significant (p = 0.051) in experiment 2. These results are discussed in relation to existing literature and potential to improve the profitability of cattle fattening in central Vietnam.

• Asian-Australasian Journal of Animal Sciences
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• 제29권6호
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• pp.823-829
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• 2016

Eight Holstein steers ($216{\pm}48kg$ body weight) fitted with ruminal and duodenal cannulas were used to evaluate effects of wheat straw processing (ground vs pelleted) at two straw inclusion rates (7% and 14%; dry matter basis) in dry rolled or steam-flaked corn-based finishing diets on characteristics of digestion. The experimental design was a split plot consisting of two simultaneous $4{\times}4$ Latin squares. Increasing straw level reduced ruminal (p<0.01) and total tract (p = 0.03) organic matter (OM) digestion. As expected, increasing wheat straw level from 7% to 14% decreased (p<0.05) ruminal and total tract digestion of OM. Digestion of neutral detergent fiber (NDF) and starch, per se, were not affected (p>0.10) by wheat straw level. Likewise, straw level did not influence ruminal acetate and propionate molar proportions or estimated methane production (p>0.10). Pelleting straw did not affect ($p{\geq}0.48$) ruminal digestion of OM, NDF, and starch, or microbial efficiency. Ruminal feed N digestion was greater (7.4%; p = 0.02) for ground than for pelleted wheat straw diets. Although ruminal starch digestion was not affected by straw processing, post-ruminal (p<0.01), and total-tract starch (p = 0.05) digestion were greater for ground than for pelleted wheat straw diets, resulting in a tendency for increased post-ruminal (p = 0.06) and total tract (p = 0.07) OM digestion. Pelleting wheat straw decreased (p<0.01) ruminal pH, although ruminal volatile fatty acids (VFA) concentration and estimated methane were not affected ($p{\geq}0.27$). Ruminal digestion of OM and starch, and post-ruminal and total tract digestion of OM, starch and N were greater (p<0.01) for steam-flaked than for dry rolled corn-based diets. Ruminal NDF digestion was greater (p = 0.02) for dry rolled than for steam-flaked corn, although total tract NDF digestion was unaffected (p = 0.94). Ruminal microbial efficiency and ruminal degradation of feed N were not affected (p>0.14) by corn processing. However, microbial N flow to the small intestine and ruminal N efficiency (non-ammonia N flow to the small intestine/N intake) were greater (p<0.01) for steam-flaked than for dry rolled corn-based diets. Ruminal pH and total VFA concentration were not affected ($p{\geq}0.16$) by corn processing method. Compared with dry rolled corn, steam-flaked corn-based diets resulted in decreased acetate:propionate molar ratio (p = 0.02). It is concluded that at 7% or 14% straw inclusion rate, changes in physical characteristics of wheat straw brought about by pelleting negatively impact OM digestion of both steam-flaked and dry-rolled corn-based finishing diets. This effect is due to decreased post-ruminal starch digestion. Replacement of ground straw with pelleted straw also may decrease ruminal pH.

• Asian-Australasian Journal of Animal Sciences
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• 제29권11호
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• pp.1585-1592
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• 2016

The present experiment was conducted to evaluate the effect of simulated heat stress on digestibility and methane ($CH_4$) emission. Four non-lactating crossbred cattle were exposed to $25^{\circ}C$, $30^{\circ}C$, $35^{\circ}C$, and $40^{\circ}C$ temperature with a relative humidity of 40% to 50% in a climatic chamber from 10:00 hours to 15:00 hours every day for 27 days. The physiological responses were recorded at 15:00 hours every day. The blood samples were collected at 15:00 hours on 1st, 6th, 11th, 16th, and 21st days and serum was collected for biochemical analysis. After 21 days, fecal and feed samples were collected continuously for six days for the estimation of digestibility. In the last 48 hours gas samples were collected continuously to estimate $CH_4$ emission. Heat stress in experimental animals at $35^{\circ}C$ and $40^{\circ}C$ was evident from an alteration (p<0.05) in rectal temperature, respiratory rate, pulse rate, water intake and serum thyroxin levels. The serum lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase activity and protein, urea, creatinine and triglyceride concentration changed (p<0.05), and body weight of the animals decreased (p<0.05) after temperature exposure at $40^{\circ}C$. The dry matter intake (DMI) was lower (p<0.05) at $40^{\circ}C$ exposure. The dry matter and neutral detergent fibre digestibilities were higher (p<0.05) at $35^{\circ}C$ compared to $25^{\circ}C$ and $30^{\circ}C$ exposure whereas, organic matter (OM) and acid detergent fibre digestibilities were higher (p<0.05) at $35^{\circ}C$ than $40^{\circ}C$ thermal exposure. The $CH_4$ emission/kg DMI and organic matter intake (OMI) declined (p<0.05) with increase in exposure temperature and reached its lowest levels at $40^{\circ}C$. It can be concluded from the present study that the digestibility and $CH_4$ emission were affected by intensity of heat stress. Further studies are necessary with respect to ruminal microbial changes to justify the variation in the digestibility and $CH_4$ emission during differential heat stress.

• Asian-Australasian Journal of Animal Sciences
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• 제27권8호
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• pp.1082-1087
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• 2014

Thirty-two lambs were distributed in eight treatments under $2{\times}2{\times}2$ factorial experiment to compare the effects of two levels of selenium (0.2 to 5 mg/kg dry matter [DM]), sulphur (0.25% and 0.37%) and copper (8 and 25 mg/kg DM) levels on selenium concentration in liver and serum of lambs. A liver biopsy was done on all animals and blood samples were collected from the jugular vein prior to the beginning of the treatments. The blood was sampled every thirty days and the liver was sampled after 90 days, at the slaughter. Increasing differences were noticed during the data collection period for the serum selenium concentration, and it was found to be 0.667 mg/L in animals fed with 5 mg Se/kg DM and normal sulphur and copper concentrations in their diet. However, a three-way interaction and a reduction of selenium concentration to 0.483 mg/L was verified when increasing copper and sulphur concentration levels to 25 ppm and 0.37% respectively. The liver selenium concentration was also high for diets containing higher selenium concentrations, but the antagonist effect with the increased copper and sulphur levels remained, due to interactions between these minerals. Therefore, for regions where selenium is scarce, increasing its concentration in animal diets can be an interesting option. For regions with higher levels of selenium, the antagonistic effect of interaction between these three minerals should be used by increasing copper and sulphur dietary concentrations, thus preventing possible selenium poisoning.

• 한국초지조사료학회지
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• 제23권3호
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• pp.211-218
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• 2003

본 시험은 티모시 8품종 Climax(대조), Itasca, Alma, Comtal, Liphlea, Erecta, Argus 및 Kunpu를 축산기술연구소 대관령지소와 남원지소에서, 오차드그라스 7품종 Potomac(대조), Warrior, Ambassador, Hapsung 2호, Hapsung 20호, 93E 및 Kitamidori를 대관령지소에서 1999년부터 2002년까지 수행하였다. 티모시의 풍엽성은 Liphlea, Erecta 및 Kunpu가 다른 품종들에 비하여 좋았으며 출수시기도 Liphlea와 Kunpu가 다른 품종에 비하여 매우 빨랐다. 초장은 대조품종 Climax보다 길은 품종은 Kunpu로 다른 품종에 비하여 월등히 길었으며 월동성은 Erecta와 Kunpu가 94.0%로 가장 높았다. 오차드그라스의 풍엽성은 Hapsung 20호가 가장 우수하였고, 오차드그라스의 출수시기는 대체로 늦은 편에 속하였으나 그 중에서 Potomac이 가장 빨랐다. 또한 초장은 Hapsung 2호가 가장 길었으며 월동성도 가장 우수하였다. 티모시의 건물수량은 대관령과 남원에서 Kunpu가 각각 9,493와 13,890kg/ha로 가장 많았다. 대관령지역에서 오차드그라스의 건물수량은 국내 육성품종인 Hapsung 2호와 Hapsung 20호가 각각 8,690과 8,818kg/ha으로 가장 많았다. 두 지역에서 티모시의 ADF 평균 함량은 Climax가 33.4%로 가장 낮았고 Kunpu가 39.2%로 가장 높았다. 또한 평균 NDF 함량은 Argus가 65.4%로 낮았고 Kunpu가 69.4%로 가장 높았다. 두 지역에서 티모시의 평균 조단백질 함량은 Alma가 16.5%로 높았으며, Kunpu가 13.9%로 가장 낮았다. 조단백질 수량은 두 지역을 평균하여 대조품종 Climax 보다 높은 수량을 보인 것은 Kunpu의 1,710.5와 Liphlea의 1,536.5kg/ha였다. 대관령에서 오차드그라스의 ADF 함량은Hapsung 20호가 가장 낮았으며(33.4%), 나머지 품종들은 36.2∼37.8% 사이로 비슷한 경향을 보였으며, NDF 함량은 93E가 67.5%로 가장 낮았다. 조단백질 함량은 Hapsung 2호가 가장 높았으며(13.5%), 조단백질 수량도 1,173.2kg/ha으로 가장 높았다. 본 연구결과에 의하면, 고랭지에서 잘 적응하고 생산성이 높은 티모시 품종과 오차드그라스 품종은 각각 Kunpu와 Liphlea 및 Hapsung 2호로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권11호
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• pp.1617-1622
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• 2006

Long-term storage of feeds or feedstuffs in high temperature and humid conditions can be difficult because of microbial contamination. Essential oil isolated from industrial waste citrus peel could be used as a preservative because it is likely to have anti-bacterial and anti-fungal activity. Our objective was to determine whether different levels (0.028, 0.056 and 0.112 g/kg) of citrus essential oil (CEO) would provide anti-microbial activity and enhance preservation of animal feed without influencing rumen fermentation. At 0.112 g/kg, CEO inhibited growth of Escherichia coli (ATCC 25922) and Salmonela enteritidis (IFO 3313). Growth of E. coli recovered after 24 h of incubation, but S. enteritidis continued to be inhibited for 72 h. Preservation of antibiotic-free diets for swine was assessed by observing anti-aflatoxin activity. Aflatoxin was detected in control feed samples on days 16 (8 ppb) and 21 (8 ppb) and in anti-fungal agent (AA) treated samples on days 16 (2 ppb) and 21 (4 ppb). However, aflatoxin was not detected in feed samples treated with CEO. Treatment with CEO and AA did not influence ruminal pH, dry matter digestibility (DMD) or organic matter digestibility (OMD) over 48 h of incubation in rumen fluid. Acetate and propionate were slightly higher with CEO treatment (p<0.05), but total concentration of volatile fatty acid (VFA) was not significantly affected by treatment. Ammonia-N concentration was slightly higher for the control treatment (p<0.05). This study showed that treating feed with CEO enhances preservation of animal feed without influencing in vitro rumen fermentation.

• Asian-Australasian Journal of Animal Sciences
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• 제29권8호
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• pp.1136-1144
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• 2016

Leucaena silage was supplemented with different levels of molasses and urea to study its nutritive value and in vitro rumen fermentation efficiency. The ensiling study was randomly assigned according to a $3{\times}3$ factorial arrangement in which the first factor was molasses (M) supplement at 0%, 1%, and 2% of crop dry matter (DM) and the second was urea (U) supplement as 0%, 0.5%, and 1% of the crop DM, respectively. After 28 days of ensiling, the silage samples were collected and analyzed for chemical composition. All the nine Leucaena silages were kept for study of rumen fermentation efficiency using in vitro gas production techniques. The present result shows that supplementation of U or M did not affect DM, organic matter, neutral detergent fiber, and acid detergent fiber content in the silage. However, increasing level of U supplementation increased crude protein content while M level did not show any effect. Moreover, the combination of U and M supplement decreased the content of mimosine concentration especially with M2U1 (molasses 2% and urea 1%) silage. The result of the in vitro study shows that gas production kinetics, cumulation gas at 96 h and in vitro true digestibility increased with the increasing level of U and M supplementation especially in the combination treatments. Supplementation of M and U resulted in increasing propionic acid and total volatile fatty acid whereas, acetic acid, butyric acid concentrations and methane production were not changed. In addition, increasing U level supplementation increased $NH_3$-N concentration. Result from real-time polymerase chain reaction revealed a significant effect on total bacteria, whereas F. succinogenes and R. flavefaciens population while R. albus was not affected by the M and U supplementation. Based on this study, it could be concluded that M and urea U supplementation could improve the nutritive value of Leucaena silage and enhance in vitro rumen fermentation efficiency. This study also suggested that the combination use of M and U supplementation level was at 2% and 1%, respectively.