• Journal of Animal Science and Technology
• /
• v.45 no.3
• /
• pp.421-432
• /
• 2003

The objective of this study was to examine the effects of processing methods of corn grains on protein and starch degradability in the rumen by three ruminally cannulated dry Holstein cows. The corns for these experiments were untreated; whole corn L(density; 660 g/$\ell$), whole corn H(density; 740 g/$\ell$), and treated by four different types: Ground corn, 3.8 mm, 2.8 mm, and 1.5 mm flaked corn. The results obtained were summarized as follows: For 48 hrs, the protein degradabilities were high in order, ground corn, 1.5 mm, 2.8 mm, and 3.8 mm flaked corn(82.6, 76.5, 64.5, and 33.9%, respectively). Flaked corn grains were degraded lower than ground corn. However, as increasing the processing degree of flaking, the protein degradabilities, from 4 hrs to 48 hrs, were increased. The starch degradabilities on 48 hrs were higher in 1.5 and 2.8 mm flaked corns, ground corn, 3.8 mm flaked corn(99.1, 91.5, 89.5, and 68.9%, respectively) than whole corn L(32.0%) and whole corn H(20.5%)(P<0.05). By increasing the processing degree of flaking, the protein degradabilty between 2.8 mm and 3.8 mm was increased significantly from 68.9% to 91.5%, however, that of 1.5 mm flaked corn, processed thinner, tended to be increased slightly, but was not significantly different. From 12 hrs to 24 hrs, whole corn L was degraded little more than whole corn H in starch, was not significantly different. However, after 48 hr incubation in the rumen, whole corn L was degraded more 50% than whole corn H(P<0.05). The value of degradation parameter “a” of protein was lower in all flaked corns than in ground corn. In contrast, the value of degradation parameter “a” of starch was significantly higher in all flaked corns than in ground corn(P<0.05). It seemed that by flaking the corn grains, starch particles were gelatinized, and then, starch was degraded more rapidly, while protein was degraded more slowly. Referring to these kinds of physical characteristics of grain sources in ruminal degradabilities, it is possible to synchronize the fermentation of nitrogen and carbohydrate sources, in formulating the cattle diets.

• Journal of Animal Science and Technology
• /
• v.46 no.4
• /
• pp.613-624
• /
• 2004

This study was aimed at investigating the effect of fat supplementation with divalent ions such as MgO and $CaCl_2$ on 1) in vitro ruminal fermentation characteristics and insoluble fatty acid formation, and on 2) animal performance in finishing Hanwoo bulls. In in vitro trial, five different types of diets based on supplementation sources of fat and divalent ions, i.e. T=basal diet+4% tallow, T-Ca=T+0.5% $CaCl_2$, T-Mg=TA+0.5% MgO, T-MgCa = T +0.5% $CaCl_2$+0.5% MgO, T-caS =4% Ca salt tallow, were tested. Higher pH values were observed at 6 hr incubation(P<0.01) while higher amount of VFA were produced in diets 4 and 5 at 12 hr incubation(P<0.05). Nutrients(DM, OM, Crude protein and NDF) degradation tended to increase in divalent ions or Ca-salts treated tallow treatments compared with tallow treatment after 12 h. The amount of insoluble fatty acid increased by adding MgO or $CaCl_2$ to tallow or Ca soap tallow during incubation(P<0.05). In in vivo trial, thirty finishing Hanwoo(average BW 460kg) were divided into three groups based on fat sources and divalent ions, i.e. Control(EE 2.40), T-MgCa = control + tallow + $CaCl_2$ + MgO, T-CaS = control + Ca soap tallow (EE 5.30%). After feeding each diet for 80 days, average daily weight gain showed 0.89, 1.02, 1.17kg in diets 1, 2 and 3, respectively. The highest feed efficiency was observed(0.12) in diet 2 group, followed by diet 3 (0.10) and 1 groups(0.08; P < 0.05). In conclusion, the present results could be sununarized that the performance of Hanwoo bulls was improved by tallow with divalent ions without any negative effect on rumen fermentation.

• Journal of Animal Science and Technology
• /
• v.49 no.5
• /
• pp.657-666
• /
• 2007

This study was conducted to evaluate the effects of dietary addition of caprylic acid(CA)-cyclodextrin (CD) complex on in vitro fermentation characteristics, total gas and methane production. Experiment was done with six treatment groups; 1) no CA-CD complex(control), 2) CA 20 mg(T1), 3) CD 830 mg(T2), 4) CA-CD complex 425 mg(T3), CA-CD complex 850mg(T4), CA-CD complex 1,700 mg(T5). Ruminal pH, ammonia and total VFA concentrations of T2, T3, T4 and T5 were lower(P<0.05) than those of control and T1 for the 12h incubation. The increase in molar percentage of propionate was observed in T4 and T5 compared with control and T2 for the 8h incubation(P<0.05), however, the ratio of acetate to propionate was unchanged in all treatments. Total gas of T1 was lower than that of control, but T2, T3, T4 and T5 were higher compared with control for 12h incubation(P<0.05). If the methane ratio (as %) to total gas for all treatments was compared, T3, T4 and T5(CA-CD supplemented groups) averaged 2.7% whereas control, T1 and T2 showed 3.4, 2.8 and 5.1%, respectively. Therefore, according to these results, it might be concluded that supplementation of CA-CD complex could reduce methane production without disrupting ruminal fermentation.

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

• Journal of Animal Science and Technology
• /
• v.49 no.6
• /
• pp.801-818
• /
• 2007

This study was carried out to determine the effects of processing methods of barley as a proper source of grain in diets of Hanwoo on fermentation pattern in the rumen fluid and digestibility of the diets, the growth performance and carcass characteristics of Hanwoo. The degree of ruminal pH change in the cows fed diets of the Corn(corn basis) and GDRB(ground and dry-rolled barley) tended to be greater than those in the cows fed other two diets (ground barley, GB and dry-rolled barley, DRB). The diet of GDRB showed the lowest ruminal pH(5.5), indicating the rapid degradation of the diet in the rumen. Although ammonia concentration was not affected by diet, the GR and DBR diets maintained the low concentrations of ruminal ammonia compared with other two treatments. And the effects of feeding processed barley grain on body weight gain and meat quality of Hanwoo steers were as follows. Steers fed DRB diet had the highest body weight, 683.0kg at 28 months old, while those fed the GDRB showed the lowest body weight, 653.3kg. The average daily gain(ADG) was similar between the steers fed Corn and GR throughout the whole period, but the GDRB showed the lowest ADG. The steers fed the DRB showed the significant increase in ADG(0.89kg/d from 19 to 23 months old and 0.43kg/d from 24 to 28 months old) compared with those fed other diets. Feeding diets containing corn and/or barley did not influence live body weight, cold carcass weight, carcass yield, back-fat thickness and carcass grade of Hanwoo steers.

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

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