• Asian-Australasian Journal of Animal Sciences
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• 제20권9호
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• pp.1374-1388
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• 2007

Three experiments were conducted to investigate the hypothesis that cows grazing on pasture produce the highest proportion of c-9 t-11 CLA in milk fat and no further increase can be achieved through supplementation of diets rich in linoleic acid, such as full-fat extruded soybeans or soybean oil. In experiment 1, 18 lactating Holstein cows were used in a randomized complete block design with measurements made from wk 4 to 6 of the experiment. In experiment 2, three cannulated lactating Holstein cows were used in a $3{\times}3$ Latin square design. Each period was 4 wk with measurements made in the final wk of each period. Cows in both experiments were assigned at random to treatments: a, conventional total mixed ration (TMR); b, pasture (PS); or c, PS supplemented with 2.5 kg/cow per day of full-fat extruded soybeans (PES). In both experiments, feed intake, milk yield, milk composition, and fatty acid profile of milk and blood serum were measured, along with fatty acid composition of bacteria harvested from rumen digesta in experiment 2. In experiment 3, 10 cows which had continuously grazed a pasture for six weeks were assigned to two groups, with one group (n = 5) on pasture diet alone (PS) and the other group (n = 5) supplemented with 452 g of soy oil/cow per day for 7 d (OIL). In experiment 1, cows in PS treatment produced 350% more c-9, t-11 CLA compared with cows in TMR treatment (1.70 vs. 0.5% of fat), with no further increase for cows in PES treatment (1.50% of fat). Serum c-9, t-11 CLA increased by 233% in PS treatment compared with TMR treatment (0.21 vs. 0.09% of fat) with no further increase for cows in PES treatment (0.18% of fat). In experiment 2, cows in PS treatment produced 300% more c-9 t-11 CLA in their milk fat compared with cows in TMR treatment (1.77 vs. 0.59% of fat), but no further increase for cows in PES treatment (1.84% of fat) was observed. Serum c-9, t-11 CLA increased by 250% for cows in PS treatment compared with cows in TMR treatment (0.27 vs. 0.11% of fat), with no further increase for cows in PES treatment (0.31% of fat). The c-9, t-11 CLA content of ruminal bacteria for cows in PS treatment was 200% or more of TMR treatment, but no further increase in bacterial c-9, t-11 CLA for cows in PES treatment was observed. Supplementation of soy oil in experiment 3 also did not increase the c-9 t-11 CLA content of milk fat compared with cows fed a full pasture diet (1.60 vs. 1.54% of fat). Based on these findings, it was concluded that supplementing with feeds rich in linoleic acid, such as full-fat extruded soybeans or an equivalent amount of soy oil, to cows grazing perennial ryegrass pasture may not increase milk fat c-9 t-11 CLA contents.

• Asian-Australasian Journal of Animal Sciences
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• 제29권4호
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• pp.500-508
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• 2016

This study was conducted to investigate the effects of Momordica charantia saponin (MCS) on ruminal fermentation of maize stover and abundance of selected microbial populations in vitro. Five levels of MCS supplements (0, 0.01, 0.06, 0.30, 0.60 mg/mL) were tested. The pH, $NH_3-N$, and volatile fatty acid were measured at 6, 24, 48 h of in vitro mixed incubation fluids, whilst the selected microbial populations were determined at 6 and 24 h. The high dose of MCS increased the initial fractional rate of degradation at t-value = 0 ($FRD_0$) and the fractional rate of gas production (k), but decreased the theoretical maximum of gas production ($V_F$) and the half-life ($t_{0.5}$) compared with the control. The $NH_3-N$ concentration reached the lowest concentration with 0.01 mg MCS/mL at 6 h. The MSC inclusion increased (p<0.001) the molar proportion of butyrate, isovalerate at 24 h and 48 h, and the molar proportion of acetate at 24 h, but then decreased (p<0.05) them at 48 h. The molar proportion of valerate was increased (p<0.05) at 24 h. The acetate to propionate ratio (A/P; linear, p<0.01) was increased at 24 h, but reached the least value at the level of 0.30 mg/mL MCS. The MCS inclusion decreased (p<0.05) the molar proportion of propionate at 24 h and then increased it at 48 h. The concentration of total volatile fatty acid was decreased (p<0.001) at 24 h, but reached the greatest concentration at the level of 0.01 mg/mL and the least concentration at the level of 0.60 mg/mL. The relative abundance of Ruminococcus albus was increased at 6 h and 24 h, and the relative abundance of Fibrobacter succinogenes was the lowest (p<0.05) at 0.60 mg/mL at 6 h and 24 h. The relative abundance of Butyrivibrio fibrisolvens and fungus reached the greatest value (p<0.05) at low doses of MCS inclusion and the least value (p<0.05) at 0.60 mg/mL at 24 h. The present results demonstrates that a high level of MCS quickly inhibits in vitro fermentation of maize stover, while MCS at low doses has the ability to modulate the ruminal fermentation pattern by regulating the number of functional rumen microbes including cellulolytic bacteria and fungi populations, and may have potential as a feed additive applied in the diets of ruminants.

• Asian-Australasian Journal of Animal Sciences
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• 제11권5호
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• pp.510-521
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• 1998

The effects of two types of protein, soybean meal (SBM) and fish meal (FM); and two types of energy supplements, corn flour (CF) and paper pulp (PP), on intake of guinea grass (Panicum maximum), fibre digestion and microbial activities in four Merino rams with an average weight of $54.4{\pm}4.5kg$ were studied. Each animal was fitted with a ruminal cannula and a duodenal cannula at the proximal position. The animals were fed twice daily with chopped guinea grass (5 cm) ad libitum and one of the four dietary supplements: 170 g FM+268 g PP; 170 g FM+268 g CF; 200 g SBM+200 g PP or 200 g SBM+200 g CF. All the supplements were mixed with 100 g molasses. In sacco and in vivo digestibilities, digesta flow rates, fermentation and microbial population were studied in a $4{\times}4$ Latin square design with a $2{\times}2$ factorial arrangement of dietary treatments. The effects of energy or protein sources were not significant on grass intake of sheep. The potential degradabilities of NDF and ADF were not significantly affected by any of the supplements. However, the energy and protein sources had significant efects on disappearance rate of NDF and ADF. The disappearance rate of both NDF and ADF were significantly (p < 0.05) higher in animals fed PP when compared to animals fed CF. Animals fed FM also showed significantly (p < 0.03) higher disappearance rate of ADF than those fed SBM. Animals fed PP showed better digestion in the rumen and total tract. Total flow of NDF and ADF through the duodenum was not significantly affected by the various supplements. The mean rumen pH values (5.8-6.1) were not significantly different among the four different diets. The concentration of rumen ammonia was significantly (p < 0.0001) higher in animals fed SBM (235-266.4 mg N/L) supplement than in animals fed FM (174.9-179.7 mg N/L), while total VFA concentration was not significantly affected by both energy and protein supplements. Mean values of total VFA ranged from 72.5-82.3 mM. Molar proportions of acetate, propionate and butyrate were typical of a roughage type fermentation. Molar proportion of acetate was significantly (p < 0.0001) higher in sheep fed PP when compared to sheep fed CF. Animals fed FM had higher total viable bacterial counts, while animals fed CF showed higher protozoal numbers. Proportions of cellulolytic bacteria were only slightly higher in animals fed SBM or PP.

• Journal of Animal Science and Technology
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• 제65권1호
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• pp.132-148
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• 2023

Ruminants are the main contributors to methane (CH₄), a greenhouse gas emitted by livestock, which leads to global warming. In addition, animals experience heat stress (HS) when exposed to high ambient temperatures. Organic trace minerals are commonly used to prevent the adverse effects of HS in ruminants; however, little is known about the role of these minerals in reducing enteric methane emissions. Hence, this study aimed to investigate the influence of dietary organic trace minerals on rumen fermentation characteristics, enteric methane emissions, and the composition of rumen bacteria and methanogens in heat-stressed dairy steers. Holstein (n=3) and Jersey (n=3) steers were kept separately within a 3×3 Latin square design, and the animals were exposed to HS conditions (Temperature-Humidity Index [THI], 82.79 ± 1.10). For each experiment, the treatments included a Control (Con) consisting of only basal total mixed rations (TMR), National Research Council (NRC) recommended mineral supplementation group (NM; TMR + [Se 0.1 ppm + Zn 30 ppm + Cu 10 ppm]/kg dry matter), and higher concentration of mineral supplementation group (HM; basal TMR + [Se 3.5 ppm + Zn 350 ppm + Cu 28 ppm]/kg dry matter). Higher concentrations of trace mineral supplementation had no influence on methane emissions and rumen bacterial and methanogen communities regardless of breed (p > 0.05). Holstein steers had higher ruminal pH and lower total volatile fatty acid (VFA) concentrations than Jersey steers (p < 0.05). Methane production (g/d) and yield (g/kg dry matter intake) were higher in Jersey steers than in Holstein steers (p < 0.05). The relative abundances of Methanosarcina and Methanobrevibacter olleyae were significantly higher in Holstein steers than in Jersey steers (p < 0.05). Overall, dietary organic trace minerals have no influence on enteric methane emissions in heat-stressed dairy steers; however, breed can influence it through selective alteration of the rumen methanogen community.

• 한국축산시설환경학회지
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• 제17권sup호
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• pp.7-20
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• 2011

본 연구는 친환경 한우생산을 위해 다양한 원료사료의 선택 및 구성비율 변경을 통해 메탄 저감용 사료배합비의 작성 및 적정 사육밀도에 관한 연구를 규명하기 위하여 실시하였다. 본 연구의 메탄 저감용 사료배합에 활용한 원료사료는 파쇄 옥수수와 알팔파 외 21종이었다. 또한 적정 사육밀도를 조사하기 위한 공시동물은 평균 체중 150 kg의 한우 송아지 12두를 선정하여 4개월간 실험을 수행하였다. TMR 1, 2, 3에 비해 TMR 4에서 약 3~4배정도 낮은 메탄가스 발생량을 보였으며, 사료가격에서도 저렴한 결과를 보였다. TMR 4는 TMR 1, 2 및 3에 비해 건물 소실율에서 낮은 경향을 보였으며, 메탄생성량은 24~37%정도 감소하는 결과를 보였다. 한편, 한우 육성우의 적정 사육밀도 실험에서 저밀도 ($18m^2/head$) 및 일반 처리구 ($9m^2/head$)는 과밀도 처리구 ($6m^2/head$)에 비해 총 증체량, 일당증체량 및 사료요구율이 개선되는 결과를 보였다. 또한 건강과 질병에 관련된 혈액성분에서 저밀도 및 일반 처리구는 영양대사 및 건강에 관련된 total protein, glucose, AST, ALT 및 GGT 농도가 과밀도 처리구에 비해 효과적으로 개선되는 결과를 보였다. 체위 발육(development of body size)의 경우 저밀도 및 일반 처리구의 체중, 흉폭, 요각폭 및 곤폭은 고밀도 처리구에 비해 현저하게 증가하였으며, 특히, 저밀도 처리구는 일반 처리구보다 체위발육이 우수한 결과를 보였다. 그리고 저밀도 및 일반 처리구는 고밀도 처리구에 비해 깔짚의 수분 함량, 대장균 및 콕시듐의 조절에서도 긍정적인 결과를 보였다. 이와같이 한우 육성우의 적정 사육밀도는 두당 $6m^2$ 이상이 바람직한 것으로 판단된다. 따라서 본 연구에서는 원료사료의 선택 및 구성비율 변경을 통해 메탄 생성량을 저감시킬 수 있는 가능성을 사료자원의 배합비 조정으로 메탄 저감용 사료생산의 가능성을 제시하였으며, 사육밀도는 한우의 성장과 발육에 중요한 요인임을 알 수 있었다. 따라서 본 연구에서는 적절한 원료사료의 선택 및 구성비율 변경을 통해 메탄 발생량 조절의 가능성을 제시하였으며, 사육밀도는 한우의 성장과 발육에 중요한 요인임을 확인할 수 있었다.