• Journal of Animal Science and Technology
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• 제61권2호
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• pp.98-108
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• 2019

Four Korean native steers ($511{\pm}17.2kg$; $2{\times}2$ replicated crossover design) fitted with duodenal cannulas were used to investigate the influence of oral administration of soluble whey protein (WP; 82.29% crude protein) on ruminal fermentation, gastrointestinal (GI) hormone secretion in the blood, pancreatic ${\alpha}$-amylase activity in the duodenum, and disappearance rate in each segment of the GI tract. Steers were orally fed the basal diet (control; TMR [total mixed ration] 9 kg/d) or the basal diet with enriched WP (400 g/d) for 14 days. The apparent crude protein disappearance rate in the rumen of the WP was higher than in control (p < 0.05). However, no difference between groups was observed in the apparent crude protein disappearance rate in the intestine and the apparent starch disappearance rates in the rumen, GI tract. The level of cholecystokinin, secretin, and ghrelin in serum and pancreatic ${\alpha}$-amylase activity in the duodenum of the WP also did not change. The changes in the level of blood urea nitrogen related to protein metabolism were higher in the WP than in the control (p < 0.05). However, the levels of total protein, lipid, carbohydrate and mineral metabolites did not change. Consequently, we suggest that the oral administration of WP in steers assisted in ruminal fermentation due to the population increase of microbes in the rumen but did not improve the starch digestion rate in the small intestine because GI hormone secretion in the blood and pancreatic ${\alpha}$-amylase activity did not change.

• Asian-Australasian Journal of Animal Sciences
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• 제31권2호
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• pp.230-236
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• 2018

Objective: Two ex vivo experiments were conducted to verify the effect of barley grain (Nusrat cultivar) treated with alkaline compounds (AC) including alum, ammonium, and sodium hydroxide or cation-exchanged organic extracts (OE) prepared from alfalfa hay, sugar beet pulp and Ulva Fasciata, on extent and digestion of starch. Methods: In the first study, the in vitro first order disappearance kinetic parameters of dry matter (DM), crude protein (CP) and starch were estimated using a non-linear model ($D_{(t)}=D_{(i)}{\cdot}e^{(-k_d{\cdot}time)}+I$, where: $D_{(t)}$ = potentially digestible residues at any time, $D_{(i)}$ = potentially digestible fraction at any time, $k_d$ = fractional rate constant of digestion (/h), I = indigestible fraction at any time). In the second experiment, the ruminal and post-ruminal disappearance of DM, CP, and starch were determined using in situ mobile nylon bag. Results: Barley grains treated with alum and alfalfa extract had a higher constant rate of starch digestion (0.11 and 0.09/h) than others. Barley grain treated with OE had a higher constant rate of CP digestion and that of treated with AC had a higher constant rate of starch digestion (0.08 and 0.11/h) compared with those of the other treatments. The indigestible fraction of starch treated with alum and sugar beet pulp extract was higher than that of the control group (0.24 and 0.25 vs 0.21). Barley grain treated with AC and OE had significant CP disappearance in the rumen, post-rumen and total tract, and also starch disappearance for post-rumen and total tract compared with the untreated (p<0.001). Conclusion: This study demonstrated that AC and OE might have positive effects on the starch degradation of the barley grain. In addition, treating barley grain with alum and sugar beet pulp extract could change the site and extend digestion of protein and starch.

• Asian-Australasian Journal of Animal Sciences
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• 제24권7호
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• pp.929-939
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• 2011

The effects of micronization on in situ and in vitro nutrient disappearances of wheat, barley and corn were investigated in a series of experiments. In Experiment 1, chemical composition and in situ dry matter disappearance (DMD) of six varieties of wheat were determined. In addition, an in vitro study was completed using ground micronized and unmicronized wheat (var. Kansas). In Experiment 2, three varieties of wheat (Kansas, Sceptre and Laura) and in Experiment 3, three cereal grains (wheat, barley and corn) were either micronized for 1 min to attain internal kernel temperatures of 90-100$^{\circ}C$ or not (controls), and DM, protein and starch disappearances were estimated. In Experiment 2, an in vitro study was also completed using ground micronized and unmicronized wheat (var. Kansas). Wheat samples varied with respect to crude protein (10.0-21.2%), starch (61.6-73.9%), NDF (8.5-11.8%), volume weight (753-842 g/L) and kernel hardness (0.0-32.0). Rate (p = 0.003) and extent (p = 0.001) of in situ DMD differed among wheat varieties. Correlations between in situ kinetics, and chemical and physical properties of wheat varieties showed that protein content was negatively correlated with the rate of disappearance ($r^2$ = -0.77). Micronization of all grains markedly reduced (p = 0.001) the rate and extent of DM, and protein disappearances as compared to control samples. Micronization increased (p<0.05) the digestion of starch in wheat. However, release of ammonia into the incubation medium was markedly reduced (p<0.05), suggesting that micronization increased the resistance of protein to microbial digestion. Disappearances of DM, protein and starch differed (p = 0.001) among cereal grains with wheat>barley>corn. Micronization reduced the rate of DM disappearance (p = 0.011) and slowly degradable protein fractions (p = 0.03), however, increased (p = 0.004) slowly degradable starch fractions of all three cereals. Examination of in situ samples by scanning electron microscopy confirmed that microbial colonization focused on starch granules in micronized grains, and that the protein matrix exhibited resistance to microbial colonization. These results suggest that micronization may be used to increase the ruminal escape value of protein in cereal grains, but may lead to increased starch digestion if grains are finely ground.

• Animal Bioscience
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• 제35권2호
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• pp.217-223
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• 2022

Objective: The aim of this study was to determine the effects of feeding starch sugar byproducts (SSBs) on in situ disappearance rate, performance, and carcass characteristics of Hanwoo steers in the late finishing stage. Methods: To determine the in situ disappearance rate, nylon bags filled with 5 g of SSB were inserted into the ventral sac of two cannulated Holsteins cows and incubated for 0, 2, 4, 8, 16, 24, and 48 h. A total of 30 Hanwoo steers were fed the experimental diets, which were basal diet (control) and 7% SSB on an as-fed basis (4.35% dry matter [DM]), formulated according to requirements of the Korean Feeding Standard for Hanwoo. The experiment was conducted over 80 days using a completely randomized block design. Results: Soluble fraction a of DM and organic matter (OM) was 44.20% and 64.60% DM, fraction b was 23.00% and 19.40% DM, and c values (the rate of degradation of fraction b) were 0.04 and 0.04/h, respectively. The effective degradability of DM at rumen solid outflow rates of 0.02, 0.05, and 0.08/h was 59.83, 54.75, and 52.16, respectively, and for OM was 77.78, 73.52, and 71.34, respectively. Initial and final body weight, average daily gain, DM intake, and gain:feed did not differ significantly between control and SSB groups during the entire experimental period. Carcass traits of Hanwoo steers with SSB supplementation were not significantly different between treatments except for dressing percentage, which was greater with SSB treatment. The content of saturated fatty acid (SFA) was greater and that of unsaturated fatty acids (UFA) was lower in the SSB group than in the control group. The ratio of UFA to SFA was significantly lower in the SSB group than in the control group. Conclusion: A total mixed ration containing less than 4.0% DM of SSBs can be used in Hanwoo steers without a decrease in productivity and carcass traits.

• Journal of Animal Science and Technology
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• 제47권5호
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• pp.789-804
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• 2005

본 연구는 액상 DFM(Bacillus spp.)을 완전혼합사료(실험 1) 및 다양한 비율의 starch와 cellulose에 적용(실험 2) 하였을 때, 반추위내 발효와 섬유소분해효소활성에 미치는 영향을 평가하기 위해 in vitro 배양을 24시간동안 실시하였다. 실험 1의 처리구는 완전혼합사료에 액상 DFM 0%(대조구), 0.025%, 0.05%로 각각 첨가하였다. 실험 1에서, 0.025%구는 배양 6, 9시간에서 대조구와는 유의한 차이가 없었으나, 0.05%구보다는 유의하게 낮은 결과를 보였다(P<0.05). 암모니아질소농도와 휘발성지방산농도는 액상 DFM에 의하여 영향을 받지 않았다. 하지만, A:P비율은 DFM의 적용으로 배양 24시간에 대조구에 비하여 0.05%구에서 유의한 증가를 나타내었다(P<0.05). 액상 DFM적용에 의한 섬유소분해효소활력은 전반적으로 유의한 효과가 나타나지 않았지만, CMCase는 배양 6시간에 대조구에 비하여 유의한 증가를 나타내었다(P<0.05). 하지만, xylanase는 배양 12시간의 0.05%구에서 오히려 액상 DFM의 적용으로 유의하게 감소하였다(P<0.05). 반추위내 건물소실율은 액상 DFM의 첨가수준에 의해 유의한 차이가 나타나지 않았다. 실험 2는 다양한 비율(90:10, 70:30, 50:50, 30:70, 10:90)의 starch와 cellulose에 액상 DFM을 각 비율에 대하여 대조구(0%)와 첨가구(0.025%)로 나누어 반추위액을 이용하여 배양하였다. 반추위내 pH는 액상 DFM의 첨가로 유의한 영향을 받지 않았고, starch의 비율이 증가함에 따라 부분적으로 유의하게 감소하였다(P<0.05). 암모니아질소농도는 액상 DFM의 첨가와 starch 및 cellulose의 비율에 의하여 유의한 영향을 받지 않았다. 하지만, 배양 9시간의 70:30비율에서 액상 DFM첨가구가 35.65mg/dL의 암모니아질소농도를 나타내어 대조구의 65.05mg/dL에 비하여 유의하게 감소하였다(P<0.05). 휘발성지방산농도는 70:30비율의 6시간 배양에서 액상 DFM구가 대조구에 비하여 유의한 증가를 나타내었다(P<0.05). 액상 DFM의 첨가는 CMCase에는 전반적으로 유의한 영향을 미치지 않았다. 그러나 xylanase에는 90:10, 30:70 및 10:90구에서 부분적인 유의성이 인정되었다. 본 연구결과로부터, 액상 DFM의 적용은 in vitro 발효성상과 섬유소분해효소활성을 유의적으로 향상시키지 않았고, 사료의 조성에 따라 그 효과는 다양하게 나타나 일관성이 없는 것으로 평가되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제24권12호
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• pp.1690-1698
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• 2011

Feedlot and in vitro ruminal experiments were conducted to assess the effects of saponin-containing surfactant applied during tempering of barley grain on cattle growth performance and on ruminal fermentation. In the feedlot experiment, treatments with three barley grain/barley silage based diets were prepared using barley grain at 7.7% moisture (dry, D), after tempering to 18% moisture (M), or after tempering with a saponin-based surfactant included at 60 ml/t (MS). Each treatment was rolled at settings determined previously to yield optimally processed barley. A total of 180 newly weaned British${\times}$Charolais steers were fed three diets in 18 pens for a 63-d backgrounding period and 91-d finishing period to determine feed intake, growth rate and feed efficiency. Cattle were slaughtered at the end of the experiment to measure the carcass characteristics. Tempering reduced (p<0.001) volume weight and processing index, but processing characteristics were similar between MS and M. Tempering increased (p<0.05) growth during backgrounding only, compared with D, but did not affect feed intake in either phase. During backgrounding, feed efficiency was improved with tempering, but during finishing and overall this response was only observed with the surfactant. Tempering did not affect carcass weight, fat content or meat yield. Surfactant doubled the proportion of carcasses grading AAA. In the in vitro experiment, barley (500 mg; ground to <1.0 mm or steam-rolled) was incubated in buffered ruminal fluid (40 ml) without or with surfactant up to 20 ${\mu}l/g$ DM substrate for 24 h. Surfactant increased (p<0.05) apparent DM disappearance and starch digestibility but reduced productions of gas and the volatile fatty acid and acetate:propionate ratio, irrespective of barley particle size. Compared with feeding diets prepared with non-tempered barley, tempering with surfactant increased the feed efficiency of feedlot steers. This may have arisen from alteration in processing characteristics of barley grain by surfactant rather than its direct effect on rumen microbial fermentation.