• Asian-Australasian Journal of Animal Sciences
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• 제20권1호
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• pp.45-51
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• 2007

A growth trial (Expt. 1) and an in vitro fermentation experiment (Expt. 2) were conducted to determine the response of growth performance, cecal fermentation characteristics and in vitro gas production to incremental levels of substitution of digestible fiber for lignified fiber in the diet of weaned rabbits. Three diets, formulated by substituting soyhulls (SH; used as digestible fiber source) for soybean straw (used as lignified fiber source) at substitution levels of 0, 25 and 50%, were used in a factorial design. In the growth trial (Expt. 1), increasing levels of SH substitution resulted in a quadratic increase in daily body weight gain rate (p<0.04) and feed conversion efficiency (p<0.02), but in a numerical decrease in dietary DM intake (p=0.15). When SH were included in the diet at 25% substitution level, rabbits had the highest rate of liveweight gain and feed conversion efficiency. As SH substitution level increased, pH values and ammonia-N of cecal contents linearly (p<0.001) decreased, but total VFA concentration linearly (p<0.03) increased. With incremental levels of SH substitution, the percentage of acetate and butyrate linearly (p<0.05) reduced, but the percentage of propionate and minor acids linearly (p<0.03) increased. Increasing the SH substitution levels tended to increase incidence of diarrhea. In the in vitro fermentation experiment (Expt. 2), regardless of origin of substrates fermented, increasing SH substitution level resulted in increased maximal gas production (p<0.001) and shortened gas production lag time, but had no effect on gas production rate (p>0.2). These observations suggest that incrementally feeding SH to rabbits could stimulate their cecal microbial activity, allowing cecal fermentation to shift towards favoring fiber digestion. In conclusion, digestible fiber from soyhulls may partially substitute for more lignified fiber, soybean straw, without having an adverse effect on cecal fermentative and microbial activity and growth performance. For growing rabbits, about 73% of total dietary NDF should be supplied by effective NDF, the remainder could come from digestible NDF, such as soyhulls.

• Asian-Australasian Journal of Animal Sciences
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• 제8권3호
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• pp.249-254
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• 1995

The effects of bentonite (B) on rumen protozoal population and rumen fluid characteristics of sheep fed palm kernel cake (PKC) were studied for a period of 21 days. Two groups, each comprising two sheep were fed either PKC or PKC + B ad libitum A third group was left at pasture. Rumen fluid was sampled through a rumen cannula three times daily from all animals. Palm kernel cake contained 16% crude protein, 1 % crude fat and high amounts of copper, zinc, iron and manganese. Protozoal population in the rumen fluid decreased significantly (p < 0.05) after the onset of feeding PKC or PKC + B. However, sheep given bentonite supplementation at 2% of the dietary dry matter, maintained higher protozoal densities ($15{\times}10^4/ml$) when compared to animals fed only PKC ($8{\times}10^4/ml$). With both diets, the protozoa were mainly of the small entodinia species. Animals at pasture had higher protozoal population ($47{\times}10^4/ml$) with varying species of entodiniomorphids and holotrichs. Rumen fluid pH and ammonia concentration was significantly (p < 0.05) higher in animals at pasture compared to animals fed PKC or PKC + B. Volatile fatty acid concentration was significantly (p < 0.05) lower in animals fed PKC when compared to animals at pasture. There was a shift in fermentation pattern in animals fed PKC or PKC + B towards a lower acetate; and higher propionate, isovalerate and valerate. Studies in vitro also showed the positive effect of bentonite on protozoal numbers.

• Asian-Australasian Journal of Animal Sciences
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• 제15권11호
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• pp.1634-1638
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• 2002

Quantification of endogenous amino acid loss at the terminal ileum is an essential means for calculation of the true amino acid digestibility of a feedstuff. Since nitrogen appeared in the determined diet or not could shift the results very much, also, none of digestibility markers could be recovered with 100% rate at the terminal ileum, the objectives of the present study were: (1) to determine endogenous amino acid losses when fed either a casein diet or a protein-free diet and (2) to examine the reliability of chromic oxide or acid insoluble ash in the protein-free diet. Six ileal-cannulated pigs ($65{\pm}1.85 kg$ BW) with a simple T-cannula in the terminal ileum were used in a replicated $3{\times}3$ Latin square designed trial, after allowed a 14 d recuperation period. Each test period ran for 12 days comprised of a 10 d adjustment period and a 2 d collection period. The endogenous AA losses of His, Ile, Lys, Cys, Thr, Val, Trp, Asp, Glu, and Ser from pigs fed the casein diet were significantly higher than those of the protein-free diet (p<0.05). No significant difference was found in the amount of endogenous amino acid loss when determined with the different markers in the protein-free diet (p>0.05). These data suggest that endogenous amino acid loss could be underestimated when a protein-free diet is used. A direct effect of dietary peptides on the endogenous amino acid loss was found when the casein diet was fed. Our results also indicate that acid insoluble ash can be used as an inert marker as an alternative to chromic oxide when measuring endogenous amino acid loss.

• 한국어류학회지
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• 제34권3호
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• pp.172-178
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• 2022

눈볼대는 중, 대형 외끌이 어업을 비롯한 기선저인망어업에 어획되는 대표적인 어종으로 생산금액 증가와 어획량, 수산식품 선호도를 보았을 때, 상업적인 가치는 더욱 높아질 것으로 판단된다. 해양생태계가 변화하고 있지만, 눈볼대 섭식생태에 관한 선행연구는 2004년부터 2008년까지 채집된 개체들을 대상으로 수행이 되어 추가 연구수행이 필요하다. 남해에서 저층트롤어업으로 채집된 눈볼대 701개체의 전장범위는 3.3~33.1 cm로 나타났으며, 공복률은 78.3%였다. 눈볼대의 주먹이생물은 어류였으며, 어류 중에서도 멸치가 가장 우점하였다. 눈볼대는 성장함에 따라 단각류, 새우류와 같은 갑각류에서 어류로 먹이생물의 전환이 이루어지는 것으로 관찰되었다. 먹이 섭식 특성의 경우, 개체당 먹이생물의 평균 중량 (mW/ST)은 성장함에 따라 지속적으로 증가했고, 평균 먹이생물의 개체수(mN/ST)는 감소하다가 증가하는 것으로 나타났다. 영양단계의 범위는 3.31±0.52~3.79±0.70으로 나타났으며, 평균 영양단계는 3.62±0.64로 나타났다.