• Asian-Australasian Journal of Animal Sciences
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• v.22 no.12
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• pp.1625-1632
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• 2009

Four lactating Holstein Friesian crossbred cows, with an average initial weight of 450 kg, 48${\pm}$12 days in milk and initial milk yield of 18 kg/h/d, were randomly arranged according to a 2${\times}$2 factorial arrangement in a 4${\times}$4 in Latin square design with 21-d period to investigate the effects of type of total mixed ration (TMR) and type of whole cottonseed (WCS) on intake, digestibility and milk production. The dietary treatments were i) TMR and WCS supplementation at 0.5 kg/h/d, ii) TMR and cracked WCS (cWCS) supplementation at 0.5 kg/h/d, iii) fermented TMR (FTMR) and WCS supplementation at 0.5 kg/h/d, and iv) FTMR and cWCS supplementation at 0.5 kg/h/d. Voluntary feed intake was 15.9, 15.2, 15.4 and 15.6 kg DM/d in dietary treatment 1, 2, 3 and 4, respectively. Digestibility of DM, OM, CP, EE, NDF and ADF were not significantly different among dietary treatments. Ruminal pH, $NH_{3}-N$ and volatile fatty acids in the rumen were also not significantly different among type of TMR or type of WCS. Blood urea-N concentration was not significantly different among dietary treatments. Ruminal bacteria population tended to increase but ruminal protozoa population tended to decrease with supplementation of cWCS, but they were not affected by FTMR. Milk yield and 3.5% FCM were not statistically different among treatments (16.6, 16.2, 17.0, 16.3 kg/d and 18.0, 18.6, 19.9 and 19.0 kg/d, respectively). Milk composition was not significantly different among dietary treatments. However, unsaturated fatty acids in milk fat in cows fed FTMR were lower (p<0.05) than in cows fed TMR. In conclusion, fermentation is a conceivable method to improve the quality of TMR for long-time storage and the cracking method is suitable to release the fat from cottonseed for enhancing fatty acid deposition in milk. Thus, the combination of FTMR and cWCS supplementation would be an alternative strategy to improve performance of lactating cows.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.2
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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.

• Journal of Animal Science and Technology
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• v.56 no.4
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• pp.14.1-14.7
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• 2014

Two trials were conducted to evaluate the influence of supplemental urea withdrawal on characteristics of digestion (Trial 1) and growth performance (Trial 2) of feedlot cattle during the last 40 days on feed. Treatments consisted of a steam-flaked corn-based finishing diet supplemented with urea to provide urea fermentation potential (UFP) of 0, 0.6, and 1.2%. In Trial 1, six Holstein steers ($160{\pm}10kg$) with cannulas in the rumen and proximal duodenum were used in a replicated $3{\times}3$ Latin square experiment. Decreasing supplemental urea decreased (linear effect, $P{\leq}0.05$) ruminal OM digestion. This effect was mediated by decreases (linear effect, $P{\leq}0.05$) in ruminal digestibility of NDF and N. Passage of non-ammonia and microbial N (MN) to the small intestine decreased (linear effect, P = 0.04) with decreasing dietary urea level. Total tract digestion of OM (linear effect, P = 0.06), NDF (linear effect, P = 0.07), N (linear effect, P = 0.04) and dietary DE (linear effect, P = 0.05) decreased with decreasing urea level. Treatment effects on total tract starch digestion, although numerically small, likewise tended (linear effect, P = 0.11) to decrease with decreasing urea level. Decreased fiber digestion accounted for 51% of the variation in OM digestion. Ruminal pH was not affected by treatments averaging 5.82. Decreasing urea level decreased (linear effect, $P{\leq}0.05$) ruminal N-NH and blood urea nitrogen. In Trial 2, 90 crossbred steers ($468kg{\pm}8$), were used in a 40 d feeding trial (5 steers/pen, 6 pens/treatment) to evaluate treatment effects on final-phase growth performance. Decreasing urea level did not affect DMI, but decreased (linear effect, $P{\leq}0.03$) ADG, gain efficiency, and dietary NE. It is concluded that in addition to effects on metabolizable amino acid flow to the small intestine, depriving cattle of otherwise ruminally degradable N (RDP) during the late finishing phase may negatively impact site and extent of digestion of OM, depressing ADG, gain efficiency, and dietary NE.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.8
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• pp.1115-1120
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• 2002

The effects of seed-associated or free linseed oil on fermentation characteristics and long-chain unsaturated fatty acids composition, especially the formation of conjugated linoleic acid (CLA) and octadecenoic acid (trans-11 $C_{18:1}$, $t-C_{18:1}$) by mixed ruminal bacteria were examined in vitro. Concentrate (1% of culture solution, w/v, as-fed basis) with ground linseed (0.6% of culture solution, w/v, DM basis) or linseed oil as absorbed onto ground alfalfa hay was added to 600 ml mixed solution consisting of strained rumen fluid and artificial saliva at the ratio of 1:1 in a glass culture jar. The culture jar was covered with a glass lid with stirrer, and placed into a water-bath ($39^{\circ}C$) and incubated anaerobically up to 24 h. Seed-associated or free linseed oil did not significantly affect the pH and ammonia concentration in the culture solution. Molar percent of acetate tended to increase while that of propionate decreased with the addition of free oil treatment throughout the incubation. Differences in bacterial number were relatively small, regardless of the form of supplements. Decreasing trends in the compositions of linoleic acid ($C_{18:2}$) and linolenic acid ($C_{18:3}$) but increasing trends of stearic acid ($C_{18:0}$), $t-C_{18:1}$ and CLA compositions were found from culture contents up to 12h incubation when incubated with both ground linseed and linseed oil. The compositions of $C_{18:0}$, $C_{18:2}$ and $C_{18:3}$ were greater but those of oleic acid ($C_{18:1}$), $t-C_{18:1}$ and CLA were smaller in a culture solution containing ground linseed than those containing linseed oil. The ratio of $t-C_{18:1}$ to CLA was lower in the culture solutions containing linseed oil up to 12h incubations as compared to those containing ground linseed.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.10
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• pp.1459-1465
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• 2013

Two in vitro experiments were conducted to evaluate the effect of methylcellulose (MC) on i) bacterial detachment from rice straw as well as ii) inhibition of bacterial attachment and fiber digestibility. To evaluate the effect of MC on fibrolytic bacterial detachment (Exp 1), in vitro bacterial cultures with 0.1% (w/v) MC solution were compared with cultures without MC after 8 h incubation. The effect of MC on inhibition of bacterial attachment was determined by comparing with real-time PCR the populations of F. succinogenes, R. flavefaciens and R. albus established on rice straw pre-treated with 0.1% MC with those on untreated straw after incubation for 0, 6 and 12 h (Exp 2). The major fibrolytic bacterial attachment on rice straw showed significantly lower populations with either the addition of MC to the culture or pre-treated rice straw compared to controls (p<0.05). Also, the digestibility of rice straw with MC was significantly lower compared with control (p<0.05). The F. succinogenes population did not show detachment from rice straw, but showed an inhibition of attachment and proliferation on rice straw in accordance with a decrease of fiber digestion. The detachments of Ruminococcus species co-existed preventing the proliferations with subsequent reduction of fiber degradation by MC during the incubation. Their detachments were induced from stable colonization as well as the initial adhesion on rice straw by MC in in vitro ruminal fermentation. Furthermore, the detachment of R. albus was more sensitive to MC than was R. flavefaciens. These results showed the certain evidence that attachment of major fibrolytic bacteria had an effect on fiber digestion in the rumen, and each of fibrolytic bacteria, F. succinogenes, R. flavefaciens and R. albus had a specific mechanism of attachment and detachment to fiber.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.2
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• pp.222-237
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• 2002

Effects of high and low levels of feeding with or without protected protein on the performance of lactating goats were studied. Twenty four German Fawn goats either from 1st ($43.37{\pm}3.937$ kg and 2 year old) or 3rd $62.64{\pm}6.783$ kg and 4-5 year old) parity were used for the trial. Feeding levels were 7.2 (I) and 5.2 (II) MJ ME/litre of milk of 3.5% fat in addition to that of the maintenance allowance. At each feeding level, diet had either unprotected (U) or formaldehyde protected (P) soya-meal. Thus, four diets were IU, IP, IIU and IIP, having six animals in each. The diets were composed of hay and pellet (10:4:1 of beet pulp : barley : soya-meal). Effect of feeding level, protein protection, parity, health status and kid number on intake, milk yield, milk composition, growth rate of goats were recorded across the 21 weeks of study. High feeding level resulted increase (p<0.001) in estimated metabolizable energy (ME) and metabolizable protein (MP) availability. Dietary inclusion of protected soya-meal increased (p<0.001) the estimated MP but not the ME availability. Animals in 1st parity ate more (p<0.001) DM (111 vs. 102 g/kg $W^{0.75}$/d) than those in 3rd parity. Animals with twin kids (110 g/kg $W^{0.75}$/d) had higher (p<0.001) DM intake than those with single kid (102 g/kg $W^{0.75}$/d). Fat (4%) corrected milk (FCM) yield was not effected by high (1,924 g/d) or low (1,927 g/d) feeding level but increased (p<0.001) with protected (2,166 g/d) compared with unprotected (1,703 g/d) soya-meal. FCM yield for four dietary combinations were 1,806, 2,078, 1,600 and 2,254 g/d for diets IU, IP, IIU and IIP, respectively. For unit increase (g) in estimated MP availability relative to ME (MJ) intake, FCM yield increased ($1,418{\pm}275.6$) g daily ($r^2$=0.58; p<0.001). Milk fat (3.14 vs. 3.54%; p<0.001) and protein (2.94 vs. 3.04% p<0.05) contents were lower at high than the low feeding level. Protected protein increased (p<0.001) the fat, lactose and net energy (NE) content of milk. Milk urea concentration of 175, 183, 192 and 204 mg/l for diets IU, IP, IIU and IIP, respectively indicated lower RDP content of these diets. The RDP contents were 6.97, 6.70, 7.30 and 6.83 g/MJ of ME for diets IU, IP, IIU and IIP, respectively. Live weight change over the experimental period were 41, 6, 17 and 19 g/d. Absence of any positive response of high feeding was probably due to inefficient rumen fermentation resulting from inadequate RDP supply. Protected protein improved production performance apparently by increasing MP:ME ratio in the absorbed nutrient.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.2
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• pp.143-150
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• 2010

Three Hanwoo steers (BW $623{\pm}18.5kg$) with ruminal and duodenal cannulae were used to investigate nutrients degradability and total digestible nutrient (TDN) of whole crop rice silage (WRS) harvested at different mature stages using in situ technique. Crude protein content (mean 4.81%) decreased with progressed maturity at harvest except for WRS harvested at yellow stage. Ruminal dry matter degradability of WRS at milk stage tended to be slightly lower than that of the other stages during the entire incubation time from 12 h post-incubation. The rapidly degradable N (a-fraction) of WRS harvested at milk stage was significantly (p<0.05) higher than that of WRS at dough stage whereas the slowly degradable N (b-fraction) of WRS harvested at yellow and dough stages were statistically (p<0.05) higher than those of the other WRS. Effective protein degradability (EPD) of WRS harvested at yellow stage was numerically (compared with dough and milk stages) and statistically (compared with mature stage) higher than EPD of the other WRS. Protein digestibility of WRS at different gastric tracts did not differ (p>0.05) between the harvest stages. TDN of WRS harvested at yellow stage in Hanwoo steers was statistically (compared with milk stage) and numerically (compared with dough and mature stages) higher than TDN of the other WRS. Overall, taking present feed evaluation into consideration, WRS harvested at yellow stage may be recommended for Hanwoo steers. Further studies on in vivo rumen fermentation pattern and minimizing nutrients loss during harvest should be required for accurate feed evaluation.

• Journal of Animal Science and Technology
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• v.45 no.3
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• pp.387-396
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• 2003

This experiment was carried out to compare the effects of feeding commercial formula feed and rice straw separately (control) versus a total mixed ration (TMR) on productivity of Hanwoo steers in late stage of fattening and on ruminal fermentation characteristics and digestibilities. Ruminal digesta from the cannulated cattle were sampled at 0, 1, 2, 3, 5, 8 hour after feeding. The steers fed TMR consumed 7.4kg per day and there was no difference between feeding systems. Daily weight gain was not significantly (P>0.05) between feeding systems, however, TMR group showed lower daily gain than control group. The amount of feed consumption per kg weight gain was higher in TMR group than control group (10.5kg and 9.7kg, respectively), resulting in a greater efficiency of feed utilization for gain. In the result of appearance rates of quality grade A were 33% higher for TMR group than those in control group. Appearance rates of grade 1 showed 56% and 75% when fed the control and TMR, respectively. Digestibilities of dry matter, crude protein, crude fiber and gross energy for TMR treatment were significantly higher (P<0.01) than those of control. Prior to feeding (0 h) and each subsequent hour, the TMR resulted in higher rumen pH (P<0.05) when compared with control ration. The concentration of NH3-N for TMR treatment maintained at higher level up to 8hr after feeding, especially increased up to 28.2mg/$d\ell$ during 1-2 hour which was two times (P<0.05) more than control. The amount of total VFA showed same trends between feeding systems. However, the ratios of branched chained fatty acid such as iso-butyric acid and iso-valeric acid for TMR treatment were significantly(P<0.01) higher than control for 3-5hr. Results showed that TMR in these trials is effective feeding system for fattening Hanwoo steers in the respect of ruminal characteristics, total tract digestibility and productivities.

• Journal of Animal Science and Technology
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• v.53 no.2
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• pp.155-160
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• 2011

Present experiment was carried out to determine maintenance energy requirements for growing Hanwoo steers. Six Hanwoo steers (BW = $180.6{\pm}3.1$ kg) were used in two 3 ${\times}$ 3 latin square design with three different energy intake levels; TDN 1.70 kg (Low), 2.05 kg (Medium), 2.80 kg (High), respectively, based on the Korean Feeding Standards. Each period lasted 18 days including a 14-day adaptation and a 4-day measuring period. The steers were in the head hood chamber system (one cattle per chamber) during each measuring time to measure heat and methane production for 1 day. Dry matter intake was 2,058, 3,256 and 3,881 g/day for Low, Medium and High TDN, respectively. Increase in energy intake did not affect digestibilities of dry matter, crude protein, crude fiber, crude fat, NDF, ADF and nitrogen-free extract. Gross energy intake averaged 180.21, 292.74 and 337.15 kcal/$BW^{0.75}$ for Low, Medium and High TDN, respectively. Energy loss was 28.7% in feces and 2.1% in urine of gross energy intake. Further, energy loss from methane produced during rumen fermentation was 6~8.3%, while body heat loss averaged 34~60%. Intercept of regression equation between ME intake and retained energy indicated that the energy requirement was 109.84 kcal ME/$BW^{0.75}$.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.193-200
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• 2004

This experiment was carried out to determine energy requirements for maintenance of Hanwoo steers. Nine Hanwoo steers weighing 376.6$\pm$12.5kg were used in this experiment and fed rice straw(44%) and concentrate (56%) at three different energy levels; 0.8 times maintenance(0.8M), 1.2 times(1.2M) and 1.6 times(1.6M), respectively. Dry matter intake was 48.5, 65.9 and 86.5g/$BW^{0.75}$ for 0.8M, 1.2M and 1.6M, respectively. Increase in energy intake with the increased DM intake did not affect digestibilities of dry matter, organic matter, crude protein, crude fiber, crude fat and nitrogen-free extract. Gross energy intake averaged 190.8, 255.8 and 340.9kcal/BW0.75 for 0.8M, 1.2M and 1.6M, respectively. Energy loss was 41% feces and 0.6${\sim}$1.5% urine of gross energy intake. Further, energy loss from methane produced during rumen fermentation was 5${\sim}$9%, while body heat loss averaged 40${\sim}$60%. Intercept of the regression equation between ME intake and retained energy indicated that energy requirement for maintenance was 124.3kcal $ME/BW^{0.75}$.