• Journal of Animal Science and Technology
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• v.65 no.1
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• pp.132-148
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• 2023

Ruminants are the main contributors to methane (CH₄), a greenhouse gas emitted by livestock, which leads to global warming. In addition, animals experience heat stress (HS) when exposed to high ambient temperatures. Organic trace minerals are commonly used to prevent the adverse effects of HS in ruminants; however, little is known about the role of these minerals in reducing enteric methane emissions. Hence, this study aimed to investigate the influence of dietary organic trace minerals on rumen fermentation characteristics, enteric methane emissions, and the composition of rumen bacteria and methanogens in heat-stressed dairy steers. Holstein (n=3) and Jersey (n=3) steers were kept separately within a 3×3 Latin square design, and the animals were exposed to HS conditions (Temperature-Humidity Index [THI], 82.79 ± 1.10). For each experiment, the treatments included a Control (Con) consisting of only basal total mixed rations (TMR), National Research Council (NRC) recommended mineral supplementation group (NM; TMR + [Se 0.1 ppm + Zn 30 ppm + Cu 10 ppm]/kg dry matter), and higher concentration of mineral supplementation group (HM; basal TMR + [Se 3.5 ppm + Zn 350 ppm + Cu 28 ppm]/kg dry matter). Higher concentrations of trace mineral supplementation had no influence on methane emissions and rumen bacterial and methanogen communities regardless of breed (p > 0.05). Holstein steers had higher ruminal pH and lower total volatile fatty acid (VFA) concentrations than Jersey steers (p < 0.05). Methane production (g/d) and yield (g/kg dry matter intake) were higher in Jersey steers than in Holstein steers (p < 0.05). The relative abundances of Methanosarcina and Methanobrevibacter olleyae were significantly higher in Holstein steers than in Jersey steers (p < 0.05). Overall, dietary organic trace minerals have no influence on enteric methane emissions in heat-stressed dairy steers; however, breed can influence it through selective alteration of the rumen methanogen community.

• 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.55 no.1
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• pp.51-59
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• 2013

This study was conducted to investigate the dietary effect of total mixed rations (TMR) containing brewers grain, soybean curd and rice straw, respectively, on growth performance and carcass characteristics of Hanwoo steers. Twenty four Hanwoo steers (average body weight 168 kg) in 6 months age were randomly allocated to 4 experimental groups, which contained 6 animals per group during 22-months feeding trial. The treatment was composed of the group fed concentrate and rice straw separately (T1), the group fed TMR containing brewers grain (T2), the group fed TMR containing soybean curd (T3) and the group fed TMR containing rice straw (T4). Body weight (BW) was not different among treatment groups during the growing and middle fattening period. However, it was significantly greater in T4 group than in T2 group on the final BW (p<0.05). Average daily gain was significantly greater in TMR groups compared to T1 group on the growing and late fattening (p<0.05). However, it was not different in total average. Dry matter intake tended to be increased in TMR groups. The feed conversion ratio was significantly lower in T4 group compare to T2 group (p<0.05). According to the yield traits, carcass weight of T1, T2, T3 and T4 were 389.0, 368.4, 387.5 and 384.3 kg, respectively. The back fat thickness, rib-eye area, and yield index were not different among the groups. Meat color, fat color, texture and maturity were not significantly different among groups. However, marbling score and appearance rate of meat quality grade of over $1^+$ were greater in T2 and T3 groups compare to other groups. Therefore, these results indicated that TMR with brewers grain and soybean curd may be ameliorated the growth performance and carcass characteristics of Hanwoo steers.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.1001-1008
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• 2005

This study examined the effect of corn processing with varying rumen undegradable protein (RUP) on feed intake, milk yield, its composition and, blood characteristics in Holstein cows during the transitional period (21 days pre partum to 21 days post partum). Twenty Holstein cows were randomly assigned to four diets (five cows/diet), ground corn with 30 % RUP (GCR30), ground corn with 40 % RUP (GCR40), flaked corn with 30 % RUP (FCR30), and flaked corn with 40 % RUP (FCR40). The processed corn with varying RUP was fed in total mixed rations (TMR) to cows. Dry matter intake (DMI) was higher with 40 % RUP diet than with 30 % RUP diet, resulting in higher protein and energy intake by cows during pre and post partum (p＜0.05). However, it was not affected by corn processing during pre and post partum. Similarly milk yield was higher with 40 % RUP diet than with 30 % RUP diet. and milk yield was affected by corn processing at RUP 30 % level. Corn processing did not affected the milk fat and protein contents in dairy cows. The concentration of blood non esterified fatty acid (NEFA) were effected by RUP level with flaked corn, however, it was non-significant with RUP levels when given with ground corn. It is concluded that increasing RUP from 30 % to 40 % in iso-nitrogenous diet could increase milk yield in dairy cows during the transitional phase.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.3
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• pp.281-287
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• 1995

A study was conducted to investigate the effect of different inclusion levels of urea treated whole-crop wheat silage (UWCWS) in grass silage based rations on the performance of growing beef cattle. The winter wheat (variety, Riband) was harvested (in the summer of 1991) at a dry matter proportion of 520 g/kg and treated with feed grade urea at the rate of 37 kg/tonne crop dry matter and preserved in a heavy duty plastic bag using a silo press. The urea treated whole crop wheat silage (UWCWS) was mixed with grass silage to replace 0.00 (S100), 0.33 (S33) and 0.67 (S67) parts of the forage dry matter and fed ad libitum in a cross over design to 18 Simmental X Holstein Friesian growing beef animals. Two energy sources {one high in starch, rolled barley (RB) and one high in digestible fibre, sugar beet pulp (SBP)} were fed to supply sufficient energy for the efficient use of nitrogen by the rumen micro-organisms. The data on DMIF (dry matter intake of forage), TDMI (total dry matter intake), DLWG (daily live weight gain), FCR (feed conversion ratio) were recorded and faecal samples were collected to determine the digestibility coefficients. Results revealed that with the inclusion of UWCW in the animals' diets the DMI of the forage was significantly increased (p < 0.05). The highest DMIF was found in the treatment "S33" ($6.28{\pm}0.25kg$) where 67% of the silage dry matter was replaced with the UWCW and the lowest value for DMIF was observed in the control treatment ($5.03{\pm}0.23kg$). The DLWG did not differ significantly between the treatments. However, treatment "S100" showed a trend towards a superior DLWG. Feed conversion ratio in the control treatment differed significantly from "S67" and "S33". The addition of the UWCW in the animals' diet resulted in the lower FCR There was no effect of type of energy supplement on any aspect of performance either overall or in interaction with grass silage: UWCWS ratio. The regression and correlation coefficients for DMIF (r = 5.22 + 0.0184x*), DLWG (r = $1.04-0.00086x^{NS}$) and FCR (r = 4.78 = 0.022x*) on the inclusion of UWCW in the diet were calculated. The effect of the inclusion of UWCW on the overall digestibility coefficients was significant (p < 0.05). The addition of the UWCWS in the diet decreased the digestibility of the DM, OM, ADF and NFE but effect on the protein digestibility was non significant. The results of present study suggests that a DLWG slightly over 1 kg can be achieved with UWCW during the store period (period in which animal performance targets are low especially during winter) and the prediction of ME was overestimated as the high intake of DM did not reflect in improved animal performance.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.6
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• pp.806-811
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• 2002

A 90 d study was designed to investigate the effects of rumen undegradable protein (RUP) and a mixture of Cu, Zn and Mn proteinate (CZMP) on milk yield and composition and ovarian functions during rainy months. Twenty four Holstein${\times}$ indigenous cows in their 2nd and 3rd lactation were randomly allocated to total mixed rations (TMR) containing soy bean meal (SBM) as a source of rumen degradable protein (RDP), SBM plus CZMP, and formalin treated SBM (FSBM) as a source of RUP. Maximum and minimum temperature humidity index during the experimental period were 83.6-84.7 and 75.4-76.1. There were no differences (p>0.05) in intakes of dry matter, crude protein and net energy and in contents of butterfat, lactose and minerals. Cows on TMR containing FSBM not only lost less weight (-278, -467 and -433 g/d) with more intake of RUP (0.92, 0.58 and 0.59 kg/d) but also produced more milk (19.27, 18.23 and 18.13 kg/d) and 4% fat corrected milk (18.57, 17.57 and 17.51 kg/d) with more protein (3.06, 2.81 and 2.80%), solids-not-fat (8.69, 8.38 and 8.38%) and less milk urea N (9.3, 15.4 and 15.0 mg/dl) compared with those on TMR containing SBM and SBM+CZMP, respectively (p<0.01). However, cows on TMR containing SBM and SBM+CZMP did not differ in these respects (p>0.05). Whereas incidence of cystic ovaries at 20 and 90 d pospartum was less (p<0.01) in cows on TMR containing SBM+CZMP (37.3 and 12.5%) than those on TMR containing SBM (62.5 and 25%), it was nil for cows on TMR containing FSBM. Cows in all three group differed (p<0.01) from each other for the recurrence of first observed estrus with those on TMR containing FSBM having least days (22, 36 and 47 d) compared with their counterpart on TMR containing SBM+CZMP and SBM, repectively. The results suggest that RUP is one of the limiting factors affecting milk yield and its composition and ovarian functions during early lactation of dairy cows in the tropics.

• Journal of Animal Science and Technology
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• v.58 no.7
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• pp.24.1-24.7
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• 2016

Background: Clinoptilolite is a natural zeolite with high adsorption capacity for polar mycotoxins such as aflatoxins. The efficacy of clinoptilolite in ameliorating the toxic effects of aflatoxicosis has been proven in monogastric animals, but there is no such evidence for ruminants. The aim of this study was to evaluate, under field conditions, whether the dietary administration of clinoptilolite in dairy cows could reduce the concentration of aflatoxin M1 ($AFM_1$) in bulk-tank milk, in farms with higher than or close to $0.05{\mu}g/kg$ of milk (European maximum allowed residual level). An objective of the present study was also to investigate the effect of particle size of clinoptilolite on aflatoxin binding. Methods: Fifteen commercial Greek dairy herds with AFM1 concentrations in bulk tank milk ${\geq}0.05{\mu}g/kg$ were selected. Bulk tank milk AFM1 was determined prior to the onset and on day 7 of the experiment. Clinoptilolite was added in the total mixed rations of all farms at the rate of 200 g per animal per day, throughout this period. Two different particle sizes of clinoptilolite were used; less than 0.15 mm in 9 farms (LC group) and less than 0.8 mm in 6 farms (HC group). Results: Clinoptilolite administration significantly reduced $AFM_1$ concentrations in milk in all farms tested at an average rate of 56.2 % (SD: 15.11). The mean milk $AFM_1$ concentration recorded on Day 7 was significantly (P < 0.001) lower compared to that of Day 0 ($0.036{\pm}0.0061$ vs. $0.078{\pm}0.0074{\mu}g/kg$). In LC group farms the reduction of milk $AFM_1$ concentration was significantly higher than HC group farms ($0.046{\pm}0.0074$ vs. $0.036{\pm}0.0061{\mu}g/kg$, P = 0.002). As indicated by the Pearson correlation, there was a significant and strong linear correlation among the milk $AFM_1$ concentrations on Days 0 and 7 (R = 0.95, P < 0.001). Conclusions: Dietary administration of clinoptilolite, especially of smallest particle size, at the rate of 200 g per cow per day can effectively reduce milk $AFM_1$ concentration in dairy cattle and can be used as a preventive measure for the amelioration of the risks associated with the presence of aflatoxins in the milk of dairy cows.

• Food Science of Animal Resources
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• v.30 no.3
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• pp.512-517
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• 2010

This study was conducted to the evaluate nutritional value of corn taffy residue (CTR), a by-product from Korean traditional taffy, and to investigate the dietary effect of CTR on the yield and composition of milk from dairy cows. Relatively high concentrations of residual enzymes and sugars were found in CTR. Protein and fat concentrations were high, comparable to those of corn gluten meal. Inclusion of 1, 3, and 6% CTR in total mixed rations yielded more milk (p<0.05) than in the control group, and increased milk fat (p<0.05) in high-producing cows (approximately 30 kg). In low-producing cows, (approximately 20 kg), milk yield was increased by 1 and 6% CTR, and milk protein was enhanced by 3% CTR (p<0.05). Based on these results, utilization of CTR is recommended for production of high quality and economical animal products.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.4
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• pp.341-350
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• 2008

This trial was conducted to investigate effects of different feeding types of conventional or total mixed rations (TMR) provision on feed intake, nutrient digestibility, nitrogen retention and blood metabolite characteristics in different breeds of native and cross bred Korean black goats. Ten Korean native male goats and 10 Korean crossbred black male goats (Korean native $\times$ Australian feral crossbred, 50:50), average 18 kg of BW, were used in this trial, and each breed of Korean black goats was separated into conventional and TMR diets treatments in a randomized complete block design. Conventional diet was based on forages and commercial diet. All animals were housed in individual metabolism crates and were fed ad libitum. Water was available at all times. Experimental period totally lasted for 38 days, consisting of 14 days of adaptation, 10 days of preliminary period and 14 days of sample collection period. Daily dry matter intake was significantly (p<0.05) higher in TMR treatments of the crossbred goats. Within breeds, crossbred rather than native-bred consumed more highly, and within the feeding type, TMR diets were more fed in comparison with conventional diet. Average daily gain ranked the highest in crossbred : TMR, followed by crossbred: conventional diet, native-bred: TMR, and native-bred: conventional diet (p<0.05). Dry matter digestibility was significantly (p<0.05) higher for TMR than for conventional diets, and it was higher in crossbred than in native-bred Korea black goats. Nitrogen retention was highest in TMR treatments of crossbreed, whereas it was lowest in conventional diet of native breed (p<0.05). Plasma glucose and urea nitrogen concentrations were significantly (p<0.05) higher in crossbred than in native-bred Korean black goats. Overall, the results indicated that feeding total mixed ration to crossbred rather than native-bred Korean black goats had more favourable influences on their performances, intakes, digestibility, nitrogen retention and blood metabolite characteristics. In conclusion, it is conceived that the results may contribute to economical benefit to farms producing Korean black goats together with establishment of an efficient feeding management system.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.1
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• pp.12-16
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• 2015

This study was carried out to evaluate accurately physical characteristics of total mixed rations (TMR) by investigating the effects of physically effective neutral detergent fiber content on the growth performance and carcass characteristics in fattening steers. Twelve Hanwoo (Bos Taurus coreanae) steers aged 26 months were used in this trial. Steers were offered one of two total mixed ration (TMR) diets - High or Low physically effective neutral detergent fiber (peNDF) content groups-that were differentiated by mixing time. The carcass traits of the experimental animals were evaluated by Korea Institute for Animal Products Quality Evaluation (KAPE) after slaughter. Body weight gain during the experimental period was significantly higher (P<0.05) in the High group ($30.00{\pm}10.27kg$) compared with the Low group ($17.20{\pm}6.34kg$), and daily weight gain was also high in the former. Although there was no significant difference, the carcass weight was higher in the High group ($414.60{\pm}34.28kg$) compared with the Low group ($377.80{\pm}11.97kg$). However, the beef quality grade of the Low group ($1^{++}$) was higher than that of the High group ($1^+$). Increases in body weight gain, daily gain, and carcass weight for the High group were mainly influenced by a high level of dry matter (DM) intake and digestibility; consequently, back-fat thickness increased and the beef quality grade was lowered. Because growth performance and carcass characteristics were affected by the physical traits of the diet, we suggested that proper peNDF content is also needed for fattening steers.