• Asian-Australasian Journal of Animal Sciences
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• 제31권10호
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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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• 제3권4호
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• pp.323-330
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• 1990

Two experiments were conducted to evaluate the effect of processing and method of ensiling on the digestion and utilization of high moisture barley (HMB) in cattle. In experiment 1, four Holstein heifers were assigned in a Latin square design to diets containing 70% barley, 25% alfalfa hay and 5% supplement on a dry matter (DM) basis. Diets differed only in the type of barley fed: rolled dry barley (R-DB), rolled HBM (R-HMB), ground HMB (G-HMB) or unprocessed HMB (U-HMB). In experiment 2, three Holstein steers were fed 85.2% barley, 10.2% whole plant barley silage and 4.6% supplement on a DM basis. Again, diets differed only in the type of barley fed: R-DB, rolled HMB from a pit silo (Pit-HMB) or rolled HMB from a Harvestore silo (HAV-HMB). In experiment 1, digestibility coefficients for animals fed R-HMB were significantly higher than observed for U-HMB. While not significant, a similar trend for decreased digestibility was observed for R-DB and G-HMB. Animals fed HMB had significantly lower ruminal propionate concentrations. In addition, the rate of degradation of the degradable DM and crude protein (CP) fractions was slower for HMB than for dry barley. In experiment 2, a trend to lower digestibility coefficients was observed for animal fed R-DB compared to those fed Pit-HMB or HAV-HMB. Ruminal propionate concentrations for animals fed R-DB also tended to be higher than for those fed the HMB diets. Dry matter and CP disappearances from nylon bags was substantially lower for Pit-HMB than for R-DB or HAV-HMB. The results suggest that replacement of dry barley by rolled or unprocessed HMB in the diet of animals fed high grain diets may contribute to a more stable rumen environment.

• Asian-Australasian Journal of Animal Sciences
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• 제20권2호
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• pp.220-228
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• 2007

The nutritive value and the effect of tannins on the utilization of foliage from three commonly used legumes, Acacia nilotica, Albizia procera, and Sesbania acculeata, were determined. Three mature rumen-fistulated bullocks were used to study in sacco degradability and twelve adult sheep were randomly allocated on the basis of live weight to 4 groups of 3 in each to study the in vivo digestibility of the foliages. In all foliages, the contents of crude protein (17 to 24% of DM) were high. Fibre was especially high in Albizia (NDF 58.8% of DM vs. 21% in Sesbania and 15.4% in Acacia). Contents of both hydrolysable (4.4 to 0.05%) and condensed tannins (1.2 to 0.04%) varied from medium to low in the foliages. Acacia contained the highest level of total phenolics (20.1%), protein precipitable phenolics (13.2%) and had the highest capacity to precipitate protein (14.7%). Drying in shade reduced the tannin content in Acacia and Albizia by 48.6 and 69.3% respectively. The foliages ranked similarly for each of the different methods used to estimate tannin content and activity. Acacia and Sesbania foliage was highly degradable (85-87% potential degradability of DM in sacco), compared to Albizia (52%), indicating a minimal effect of tannins in Acacia and Sesbania. Yet, in vitro, the tannins in the Acacia inhibited microbial activity more than those in Albizia and Sesbania. Following the addition of polyethylene glycol to neutralise the tannins, gas production and microbial growth increased by 59% and 0.09 mg RNA equiv./dg microbial yield respectively in the Acacia, compared to 16-17% and 0.06 mg RNA equiv./dg microbial yield in the other foliages. There was a trend for low in vivo apparent digestibility of N in the Acacia (43.2%) and Albizia (44.2%) compared to the Sesbania (54.5%) supplemented groups. This was likely to be due to presence of tannins. Consistent with this was the low N retention (0.22 and 0.19 g N/g NI) in sheep supplemented with Acacia and Albizia compared to that for the Sesbania (0.32). Similarly, a trend for poor microbial N yield was observed in sheep fed these foliages. Across the foliages tested, an increase in tannin content was associated with a reduction in ruminal fermentation, N digestibility and N retention. For overall nutritive value, Sesbania proved to be the superior forage of the three tested.

• 한국초지조사료학회지
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• 제30권2호
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• pp.143-150
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• 2010

본 연구는 반추위 및 십이지장 cannula를 동시장착한 거세한우 3두 (평균체중 $623{\pm}18.5kg$)를 공시하여 in situ 기법으로 수확시기별 총체 벼 사일리지의 한우 생체 영양소 분해율 및 TDN을 분석하고자 실시하였다. 총체벼 사일리지의 조단백질 함량 (평균 4.81%)은 황숙기를 제외하고는 수확시기가 늦어질수록 감소하는 경향을 보였다. 총체벼 사일리지 건물의 반추 위 시간대별 분해율은 유숙기에서 배양 후 12시간 이후부터 다른 수확시기에 비해서 다소 낮은 경향을 보였다. 반추위 단백질 a-fraction은 유숙기에서 호숙기에 비해 유의성있게 높았고 (p<0.05), b-fraction의 경우, 황숙기와 호숙기가 다른 수확시기의 총체벼 사일리지보다 통계적으로 높게 나타났다 (p<0.05). 반추위 EPD는 황숙기가 다른 수확시기에 비해 수치적 (호숙기 및 유숙기) 및 통계적 (완숙기)으로 높게 나타났다. 소화장관별 총체벼 사일리지 단백질 소화율에서는 전체적으로 수확시기별 차이가 나타나지 않았다. 한우 생체 사료가치 평가를 통한 총체벼 사일리지의 TDN은 황숙기가 다른 수확시기에 비해 통계적 (유숙기) 및 수치적 (호숙기 및 완숙기)으로 높게 나타났다. 현재 연구 결과를 종합해 볼 때, 거세한우 생체 내 총체 벼 사일리지는 황숙기에 수확 시 그 사료가치가 가장 높을 것으로 판단된다. 향후 보다 정확한 사료가치 평가를 위해서 in vivo 반추위 발효 패턴 탐색 및 수확시 영양소 손실 최소화 등의 추가 연구가 필요할 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권10호
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• pp.1407-1413
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• 2005

An experiment was conducted in order to assess the effect of level of RDP:UDP ratio and level of feeding concentrate on milk yield, milk composition and nutrient utilization in lactating crossbred cattle. Twenty four medium producing (-10 kg/d, 45 to 135 days postpartum) lactating crossbred cows were divided into four groups of six animals each in a 2${\times}$2 factorial completely randomized design. The cows in group 1 were fed concentrate mixture I containing 59:41 RDP:UDP ratio (low UDP) at normal plane (LUDP+NP), in group 2 were fed low UDP ration at 115% of NRC (1989) requirements (LUDP+HP), whereas cows in group 3 were fed concentrate mixture II containing 52:48 RDP:UDP ratio (high UDP) at normal plane (HUDP+NP) and in group 4 were fed high UDP ration at 115% of NRC (1989) requirements (HUDP+HP). Green jowar was fed ad libitum as the sole roughage to all the animals. The experimental feeding trial lasted for 105 days. The total dry matter intake (DMI), DMI/100 kg body weight, DMI/kg $W^{0.75}$, digestibilities of DM, OM, CP, CF, EE and NFE and intakes of TDN and DCP did not differ significantly among the different groups and also due to both UDP level and plane of nutrition and also due to their interaction. The total dry matter intake varied from 145 g in group 1 (LUDP +NP) to 152.57 g/kg $W^{0.75}$ in group 2 (LUDP+HP) diet. However, increase in milk yield with increased UDP level and also with increased plane of nutrition was observed consistently throughout the experimental period. The average milk yield was 7.66, 8.15, 8.64 and 9.35 kg in groups 1, 2, 3 and 4, respectively and there was no significant difference in milk yield among different groups of cows. The overall daily average milk yields in cows fed with low and high UDP diets were 7.91 and 8.99 kg, respectively and at normal and higher plane of feeding the milk yields were 8.15 and 8.75 kg/day, respectively. Thus, there was 13.65% increase in milk yield due to high UDP level and 7.36% due to higher plane of feeding. The daily 4% FCM yields were 9.20 kg for low UDP diet and 10.28 kg for high UDP diet, whereas it was 9.11 kg at normal plane of feeding and 10.37 kg at higher plane of feeding. Fat yields for the corresponding treatment groups were 0.37, 0.43, 0.41 and 0.48 kg, respectively. The 4% FCM yield and also fat yield did not differ significantly among different dietary treatments and also due to UDP level and plane of nutrition, however, 4% FCM yield was increased by 11.74% with high UDP level and 13.83% with higher plane of feeding. The values for total solids, fat, lactose, solids-not-fat and gross energy contents in milk differed significantly (p<0.05) among the different groups and were significantly (p<0.05) higher in milk of cows fed LUDP+HP diet followed by HUDP+HP diet. Total solids (14.65 and 13.83%), lactose (5.44 and 4.92%), solids-not-fat (9.44 and 8.83%) and gross energy (887 and 838 kcal/kg) of milk decreased significantly (p<0.05) with increased UDP level while total solids (13.84 and 14.64), fat (4.84 and 5.36%) and gross energy (832 and 894 kcal/kg) increased significantly (p<0.05) with increase in plane of feeding. Gross and net energetic efficiencies and also gross and net efficiencies of nitrogen utilization for milk production were not significantly different among different groups and also were not affected significantly due to either UDP levels or plane of feeding. Results of the present study suggest that, increasing UDP level from 41% to 48% of CP in concentrate mixture and also increasing plane of feeding from normal (100%) to 115% of NRC requirements maintain a consistently higher milk production.