• Asian-Australasian Journal of Animal Sciences
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• 제19권11호
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• pp.1588-1596
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• 2006

An experiment was conducted to study the effect of different dietary protein levels on the performance, nutrient balances, blood biochemical parameters and thyroid hormones of crossbred calves. Thirty crossbred (Bos taurus${\times}$Bos indicus) calves aged 3-5 months were divided into 3 equal groups of 10 each and fed graded levels of crude protein, namely 100 (NP), 75 (LP) and 125 (HP) percent of the Kearl recommendations for 105 d. The calves had access to ad libitum oat hay as the basal roughage. A metabolism trial of 6 d duration was conducted at 90 d of the study. Blood collection and its analysis for various hematological and biochemical parameters as well as thyroid hormones was done both during the pre- and post-experimental periods. The fortnightly body weight changes and the net gain did not differ significantly due to dietary variation. The average daily gain was $367{\pm}21.6$, $347{\pm}22.9$ and $337{\pm}26.4g$ in calves fed NP, LP and HP diets, respectively. Averaged across the feeding trial, oat hay intake was higher (p<0.05) in NP animals than HP or LP fed groups. The dry matter (DM) intake showed no significant difference between the 3 groups but the DM digestibility was higher (p<0.05) in the HP fed animals. The digestibility of crude protein, organic matter, crude fiber and nitrogen-free extract was significantly higher (p<0.05) on HP diets compared to LP or NP diets. The calves on all 3 diets were in positive nitrogen (N) balance, however the N retention was higher (p<0.05) in HP than in LP fed calves. The intake and retention of calcium and phosphorus were similar between the treatments. The blood biochemical profile revealed no significant influence of the dietary treatments on hemoglobin, packed cell volume as well as serum levels of glucose, total protein, albumin, globulin, Ca, P, and alkaline phosphatase. Serum levels of the circulating thyroid hormones ($T_3$ and $T_4$) tended to be lower (p>0.05) on feeding of the LP diet besides showing an increasing trend with the advancement of age. Considering the similar performance and metabolic profile, it could be concluded that crossbred calves can be satisfactorily reared on 25% lower protein level as recommended by Kearl for developing countries, which would not only economize the cost of production but also help to reduce environmental pollution attributable to livestock production.

• Asian-Australasian Journal of Animal Sciences
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• 제23권2호
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• pp.197-204
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• 2010

Two studies were conducted to determine the effects of replacing 30% (% in diet DM) of lucerne (Medicago sativa L.) hay with citrus pulp in Merino ewe diets: i) an in vitro study which measured ruminal fermentation; and ii) an in vivo study in which twelve Merino ewes pre- and post-lambing were fed experimental diets in a cross-over design over 120 days to evaluate effects on ewe performance (i.e. DM intake, average daily gain (ADG) and wool growth). In both the in vitro and in vivo studies, the control treatment consisted of lucerne (91.3% in diet DM), lupins (8.3% in diet DM) and phosphate (0.42% in diet DM), while the citrus pulp treatment consisted of lucerne (57.7% in diet DM), lupins (9.5% in diet DM), phosphate (0.48% in diet DM) and fresh citrus pulp (32.3% in diet DM). Data were analysed using the mixed model procedure of SAS. In the in vitro study, gas production, total volatile fatty acid (VFA) yield, proportion of propionic acid to total VFA and in vitro dry matter digestibility (IVDMD) were higher (p<0.02) in the citrus pulp treatment compared to the control treatment. In contrast, in vitro ammonia production, pH and the acetate to propionate ratio were lower (p<0.03) for the citrus pulp treatment compared to the control treatment. In the in vivo study, DM intake of ewes fed the citrus pulp diet was lower than their control ewe counterparts throughout both the pre- and post-lambing periods (928.9 vs. 1,115.0 g/d pre-; 1,285.0 vs. 1,620.3 g/d post-lambing, p<0.01), however ADG was similar (p = 0.12). Wool growth parameters and lamb performance did not differ (p>0.32) between treatments. In summary, the in vitro study demonstrated that the replacement of 30% of a lucerne diet with fresh citrus pulp improved total VFA yield, increased total gas production and improved IVDMD, while decreasing the production of ammonia, acetic acid and rumen pH. In addition, the in vivo study demonstrated that the replacement of 30% of a lucerne diet with fresh citrus pulp pre- and post-lambing decreased intake but did not affect ewe performance in terms of ADG and wool growth. These findings, of course, would be of significant interest to sheep producers endeavouring to control cost of feed ingredients whilst maintaining productivity.

• Asian-Australasian Journal of Animal Sciences
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• 제31권12호
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• pp.1881-1889
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• 2018

Objective: In dryland areas of China, alfalfa hay (AH) is a possible substitute for concentrate feed for beef cattle. To evaluate the potential benefits of this substitution, we studied the effect of the ratio of AH intake to total dry matter (DM) intake on average daily body-weight gain (ADG), dietary energy utilization status, and economic benefit in Gansu province. Methods: In each of two feeding trials in 2016 (trial 1 [T1], July 3 to 17; trial 2 [T2], August 15 to September 23), crossbred male Simmental calves were allocated to low AH (LA), medium AH (MA), and high AH (HA) feeding groups (n = 4 per group). The target ADG was set as 1 kg for both trials. In a one-way-layout design based on conventional feeding practices in the province, calves received diets containing the different AH amounts, with a constant ratio of corn stover:total DM and decreasing rations of concentrate feed proportional to the increase in AH. Calves in T1 received AH at 15% (T1-LA), 23% (T1-MA), or 31% (T1-HA) of their dietary DM allowances; those in T2 received 9% (T2-LA), 24% (T2-MA), or 34% (T2-HA) AH. Results: Among the T1 groups, both ADG and economic benefit were highest in T1-LA; whereas in T2, they were higher in the T2-LA and T2-MA groups than in T2-HA. Energy digestibility did not significantly differ among the groups in either trial. The dietary AH inclusion ratios of 14% in the warm season and 8% to 21% in the cool season appeared to yield optimal ADG, metabolizable energy intake, and economic benefit. Conclusion: Low-level inclusion of AH, ranging from 8% to 21%, is a practical approach for beef cattle feeding. This modified feeding regimen likely will promote increased growth performance during the fattening stage of beef steers in dryland areas of Gansu province, China.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.490-496
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• 2005

Ten 18.5-month old Holstein steers were allocated into two diet groups of five and fed either concentrates as control group or potato by-products based silage (PBS) as experimental group for six months to investigate the effect of PBS on growth performance, carcass characteristics and fatty acid composition of carcass fats. The PBS diet consisted, in a DM basis, of 74.5% PBS, 16% hay, and 9.5% soybean milk residue (SMR). The control diet consisted, in a DM basis, of 82.5% concentrates and 17.5% hay. There were no significant differences in the overall average daily gain (ADG), dry matter intake (DMI), feed efficiency, yield score and meat quality score of dressed carcass between the two diet groups. There were no statistical differences in DM, crude protein (CP), and ether extract (EE) of beef and melting point of all adipose tissues from steers fed both diets. The PBS-fed steers tended to have lower Warner Bratzler shear (WBS) values than in the concentrate-fed steers (13.0 vs. 17.7 lb, p<0.1). At both sampling times 3 and 6 months of feeding period, PBS-fed steers had higher proportions of polyunsaturated fatty acids (PUFA), especially linoleic (C18:2) acids in subcutaneous fat than in control group (p<0.05). PBS-fed steers had significantly higher proportions of PUFA, especially C18:2 fatty acids than in concentrate-fed steers in carcass fats (p<0.05). In conclusion, feeding PBS to fattening steers has shown to have the same potential as concentrate feeding in terms of effect on the growth performance, feed efficiency, and carcass characteristics. Interestingly, PBS also seems preferable to concentrates because it increased the proportion of C18:2 fatty acid composition of carcass fats which is valuable for beef consumers.

• Asian-Australasian Journal of Animal Sciences
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• 제17권11호
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• pp.1535-1540
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• 2004

Six dry Holstein cows were used to evaluate the effect of dietary neutral detergent fiber (NDF) concentration and particle size (PS) on chewing activity. Treatments were arranged in a 3$\times$3 factorial design; total mixed rations contained three NDF concentrations (26, 32, 38%) and three PS (1.0, 1.5, 2.0 cm). NDF levels and particle sizes of diets were adjusted by formulating rate and cutting length of alfalfa hay and rice straw. Cows were fed twice daily at 90% of ad libitum feed intake throughout the experiment. Chewing activity was positively associated with NDF concentration, but not significantly affected by PS of diet. Eating time per unit of NDF intake was affected by PS rather than NDF concentration of diet. Time spent ruminating per unit DM or NDF intake increased with increasing NDF concentration of diet, but was not affected by PS. As the PS of diet increased, the eating time per day increased, but the rumination time decreased. In addition, as the number of rumination bolues decreased the rumination duration increased as well as the chews per bolus. The regression equation induced from relationships of NDF concentrations (NDF, %) and particle sizes (PS, cm) of diet on roughage value index (RVI, min of chewing time/kg DMI) was as follows. RVI=-19.672+1.44$\times$NDF+5.196$\times$PS, ($R^{2}$=0.81).

• Asian-Australasian Journal of Animal Sciences
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• 제17권5호
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• pp.629-632
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• 2004

The objectives of this study were to determine the effects of substituting bread by-product (BBP) for barley grain in high concentrate fattening diets for kids on nutrient intake, growth performance, and nutrient digestibility. Twenty-eight Baladi kids (body weight=17.1${\pm}$1.0 kg) were assigned randomly to 4 experimental finishing diets (7 kids/treatment) in a completely randomized design for 70 days. The control (CON) diet contained 20, 60, 11, 7 and 2% (DM basis) alfalfa hay, barley grain, soybean meal, corn grain, and mineral and vitamin mix, respectively. Bread by-product substituted barley grain by 10, 20 and 30% of the diet DM in the LBBP, MBBP, and HBBP diets, respectively. Dry matter intakes for the CON, LBBP and MBBP diets were similar (p>0.05; avg.=592 g/day), however, kids fed the HBBP diet had a lower (p<0.05) DM intake (451 g/day). Organic matter and CP intakes showed similar patterns to that observed for DM. Dietary treatments did not affect (p>0.05) average daily gain for kids fed the CON, LBBP and MBBP diets (avg.=150 g/day). Final body weights for kids fed the CON, LBBP and MBBP diets (avg. 27.1 kg) were greater (p<0.05) than for kids fed the HBBP diet (23.7 kg). Feed to gain ratio was greater for the CON, LBBP and MBBP diets (avg. 3.9) compared with the HBBP diet (5.0). No significant (p>0.05) effect of the dietary treatment was observed for DM, OM and NDF digestibility. Substituting BBP for barley grain up to 20% of the diet DM did not affect nutrient intake, growth performance and nutrient digestibility of kids and resulted in a decrease in feed cost.

• 한국축산식품학회지
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• 제33권4호
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• pp.487-492
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• 2013

The objective of this study was to examine the effect of supplementation of high linoleic ($C_{18:2}$) oil or high linolenic ($C_{18:3}$) oil to the diet on milking performance and content of conjugated linoleic acid (CLA) isomers in goat milk fat. Forty five dairy goats (Sumnen, 25 d post-partum, $62.5{\pm}1.2kg$) were randomly assigned to three treatment groups with each group of 15 dairy goats. The goats were fed a basal diet (CON) consisting 1.2 kg concentrate and 1.2 kg chopped hay (0.6 chopped alfalfa and 0.6 kg hay) daily with 4% soybean oil (SO) or 4% linseed oil (LO). Daily feed intake was not influenced (p>0.05) but daily milk yield (p<0.001) and milk fat yield (p<0.001) were significantly increased by supplementation of oils. Supplementation of oils decreased the short chain fatty acid, medium-chain fatty acid and saturated fatty acid in goat milk fat while increased trans vaccenic acid (trans-11-$C_{18:1}$, TVA), oleic acid ($C_{18:1}$), $C_{18:2}$, $C_{18:3}$, cis-9, trans-11-CLA (c9, t11-CLA), trans-10, cis- 12-conjugated linoleic acid (t10, c12-CLA), unsaturated fatty acids, mono unsaturated fatty acid and long-chain fatty acid in goat milk fat (p<0.001). Especially, c9, t11-CLA, t10, c12-CLA and ${\omega}-3$ fatty acid ($C_{18:3\;n-3}$) in milk fat were highest when goat fed LO diet. Based on the result, it is suggested that supplementation of linseed oil should be an effective method to increase CLA isomers and ${\omega}-3$ fatty acid in goat milk fat without negative effect on lactating performance.

• Asian-Australasian Journal of Animal Sciences
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• 제25권3호
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• pp.341-352
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• 2012

In large-type goats that were fed on dry forage twice daily, dry forage intake was markedly suppressed after 40 min of feeding had elapsed. The objective of this study was to determine whether or not marked decreases in dry forage intake after 40 min of feeding are mainly caused by the two factors, that is, ruminal distension and increased plasma osmolality induced thirst produced by dry forage feeding. Six large-type male esophageal- and ruminal-fistulated goats (crossbred Japanese Saanen/Nubian, aged 2 to 6 years, weighing $85.1{\pm}4.89kg$) were used in two experiments. The animals were fed ad libitum a diet of roughly crushed alfalfa hay cubes for 2 h from 10:00 to 12:00 am during two experiments. Water was withheld during feeding in both experiments but was available for a period of 30 min after completion of the 2 h feeding period. In experiment 1, saliva lost via the esophageal fistula was replenished by an intraruminal infusion of artificial parotid saliva (RIAPS) in sham feeding conditions (SFC) control, and the treatment was maintained under normal feeding conditions (NFC). In experiment 2, a RIAPS and non-insertion of a balloon (RIAPS-NB) control was conducted in the same manner as the SFC control of experiment 1. The intraruminal infusion of hypertonic solution and insertion of a balloon (RIHS-IB) treatment was carried out simultaneously to reproduce the effects of changing salt content and ruminal distension due to feed entering the rumen. The results of experiment 1 showed that due to the effects of multiple dry forage suppressing factors when feed boluses entered the rumen, eating rates in the NFC treatment decreased (p<0.05) after 40 min of feeding and cumulative dry forage intake for the 2 h feeding period reduced to 43.8% of the SFC control (p<0.01). The results of experiment 2 indicated that due to the two suppressing factors of ruminal distension and increased plasma osmolality induced thirst, eating rates in the RIHS-IB treatment were, as observed under NFC, reduced (p<0.05) and cumulative dry forage intake for the 2 h feeding period decreased to 34.0% of the RIAPS-NB control (p<0.01). The combined effects of ruminal distension and increased plasma osmolality accounted for 77.5% of the suppression of dry forage intake 40 min after the start of dry forage feeding. The results indicate that ruminal distension and increased plasma osmolality induced thirst are the main factors in the suppression of dry forage intake in large-type goats.

• Asian-Australasian Journal of Animal Sciences
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• 제24권8호
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• pp.1069-1085
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• 2011

In large-type goats that were fed on dry forage twice daily, dry forage intake was markedly suppressed after 40 min of feeding had elapsed. The objective of this study was to clarify whether or not increases in plasma osmolality and subsequent thirst sensations produced by dry forage feeding suppress dry forage intake. Eight large-type male esophageal- and ruminal-fistulated goats (crossbred Japanese Saanen/Nubian, aged 3 to 6 years, weighing $72.3{\pm}2.74$ kg) were used in two experiments conducted under sham feeding conditions. The animals were fed ad libitum a diet of roughly crushed alfalfa hay cubes for 2 h from 10:00 to 12:00 h during two experiments. Water was withheld during feeding in both experiments but was available for a period of 30 min after completion of the 2 h feeding period. In experiment 1, an intraruminal infusion of artificial parotid saliva (RIAPS) in the control replenished saliva lost via the esophageal fistula and an intraruminal infusion of hypertonic solution (RIHS) in the treatment was carried out in order to reproduce the effects of changing salt content due to feed entering the rumen. In experiment 2, the RIHS control was conducted in the same manner as the RIHS treatment of experiment 1. The treatment group consisted of RIHS-with an intravenous infusion of artificial mixed saliva (VIAMS) treatment that was carried out for 3 h to prevent increases in plasma osmolality during feeding. The results of the RIHS treatment in experiment 1 showed that ruminal fluid osmolality increased and then an increase in plasma osmolality was observed. This resulted in the production of thirst sensations and the reduction of cumulative dry forage intake to 43.3% (p<0.05) of the RIAPS control. The results of the RIHS-VIAMS treatment in experiment 2 indicated that ruminal fluid osmolality was the same as the RIHS control but plasma osmolality significantly decreased, and thirst level was markedly reduced. This caused a significant increase of 31.4% (p<0.05) in cumulative dry forage intake in the RIHS-VIAMS treatment compared to the RIHS control. These results indicate that increases in ruminal fluid osmolality during dry forage feeding indirectly suppresses dry forage intake by causing an increase in plasma osmolality and subsequently inducing thirst sensations. The results of the present study suggest that marked decreases in dry forage intake after 40 min of feeding are caused by increases in plasma osmolality and subsequent thirst sensations produced by dry forage feeding.

• Asian-Australasian Journal of Animal Sciences
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• 제16권9호
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• pp.1309-1314
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• 2003

Growth performance, nutrient digestibility and changes in caecal fermentation pattern was studied on four groups of 8 grower rabbits (soviet chinchilla) each, fed on diets containing 17 to 18% CP and $10.4-11.00MJ\;DE\;kg^{-1}$ feed. The complete diets contained mulberry leaves along with other feed ingredients at 0 (LH), 15 (ML15), 30 (ML30) and 45% (ML45) levels. In LH diet ground lucerne hay was added at 15% of the diet as roughage source. The diets were uniform in other nutritional parameters except the higher amount of hemicellulose (18.7 and 16.5%) in LH and ML15 diets. The performance of grower rabbits was better (p<0.05) on LH and ML15 diets in terms of twelve weeks weight (kg), total gain (g), average daily gain (ADG) and feed efficiency (%). Different levels of mulberry leaves in the diet did not influence the dry matter intake. Digestibility of nutrients for DM, OM, CP, NDF and energy was uniform in all the diets but the digestibility of CF, ADF and cellulose was higher (p<0.01) on ML15, ML30 and ML 45 diets. The hemicellulose digestibility was significantly higher (p<0.01) on LH (44.52%) and ML15 (48.00%) compared to ML30 (33.54%) and ML 45 (39.17%) diets. The nitrogen retention (% of intake) was higher (p<0.05) in LH and ML15 diets than ML30 and ML45 diets. The caecum weight as percent of intestine weight consistently increased (p<0.05) with increasing content of mulberry leaves in diets. Total nitrogen and $NH_3$-N was higher on LH and ML15 diets. It is concluded that incorporation of mulberry leaves can replace Lucerne hay in complete rabbit feed (15% in diet). Even at higher level i.e. 30 and 45% of the diet mulberry leaves based complete feed gave promising results.