• Asian-Australasian Journal of Animal Sciences
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• 제9권5호
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• pp.483-493
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• 1996

Advances in silage technology, including precision chop forage harvesters, improved silos, polyethylene sheeting, shear cutting silo unloaders, and the introduction of total mixed rations, have made silage the principal method of forage preservation. A better understanding of the biochemistry and microbiology of the four phases of the ensiling process has also led to the development of numerous silage additives. Although acids and acid salts still are used to ensile low-DM forages in wet climates, bacterial inoculants have become the most widely used silage additives in the past decade. Commercial inoculants can assure a rapid and efficient fermentation phase; however, in the future, these products also must contribute to other areas of silage management, including the inhibition of enterobacteria, clostridia, and yeasts and molds. Nonprotein nitrogen additives have the problems of handling, application, and reduced preservation efficiency, which have limited their wide spread use. Aerobic deterioration in the feedout phase continues to be a serious problem, especially in high-DM silages. The introduction of competitive strains of propionic acid-producing bacteria, which could assure aerobically stable silages, would improve most commercial additives. New technologies are needed that would allow the farmer to assess the chemical and microbial status of the silage crop on a given day and then use the appropriate additive(s).

• Animal Bioscience
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• 제35권2_spc호
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• pp.347-355
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• 2022

Among edible insects, black soldier fly (Hermetia illucens), yellow mealworm (Tenebrio molitor), and common housefly (Musca domestica) have been considered as an alternative protein source for pigs. Because they are easy to breed and grow in the organic wastes, and they have well-balanced nutritional value as a protein source for pigs. The black soldier fly larvae and mealworm could replace the fish meal in the diets for weaned pigs without adverse effects on growth performance and nutrient digestibility. Black soldier fly could also be included in the finishing pig's diet without any negative effects on the growth performance and pork quality of the market pigs. Insect products showed a greater standardized ileal digestibility value of amino acids than conventional animal proteins in growing pigs. Due to the limited amount of insect products used for pig feeding study, most previous pig studies have been conducted in weaned pigs. Thus, further study is needed about the optimal inclusion level of insect products in every phase diet from weaned pigs to sows. The use of insect products in swine diets has some challenges in terms of cost, supply, and safety. Lastly, intrinsic differences among insect species, processing method, and feeding phase should be taken into consideration for the use of insect products in the swine diets.

• 한국가금학회지
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• 제40권1호
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• pp.67-73
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• 2013

With an increasing concern on laying hen welfare, barn system has appeared as one of the alternatives to replace the conventional cage. This study was conducted to compare the early laying performance and egg quality at the barn system with those at the conventional cage. A total of 288 shaver-579 brown layers were used for 9 weeks ($21^{st}$ to $30^{th}$ weeks of age) feeding study. Feed consumption and egg weight were significantly (P<0.01) higher at barn than at cage. However, there were no significant differences between two housing systems on hen day egg production (HDEP), egg mass, body weight, feed efficiency and livability. In case of egg quality parameters, shell thickness, albumen height and Haugh unit were significantly (P<0.05) different between two systems. Haugh unit and albumen height were significantly higher in eggs produced at cage (88.97 and 8.16 mm) compared than those produced at barn (83.11 and 6.87 mm), whereas shell thickness was thicker in eggs produced at barn than those produced at cage. Shape index, breaking strength, blood spots and yolk index data were not influenced significantly by the types of housing system. To implement welfare bestowing production, this study showed that the barn system can replace the conventional cage without serious sacrifices on starting phase egg production. In addition, this study suggested that the barn system need to be optimized in view of daily feed consumption.

• Asian-Australasian Journal of Animal Sciences
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• 제25권10호
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• pp.1411-1418
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• 2012

The objective of the present study was to investigate the relationships between terpenes… intake and their presence in animal tissues (blood and milk) as well as in the final product (cheese). Eight dairy goats were divided in two balanced groups, representing control (C) and treatment (T) group. In T group oral administration of a mixture of terpenes (${\alpha}$-pinene, limonene and ${\beta}$-caryophyllene) was applied over a period of 18 d. Cheese was produced, from C and T groups separately, on three time points, twice during the period of terpenes… oral administration and once after the end of experiment. Terpenes were identified in blood by extraction using petroleum ether and in milk and cheese by the use of solid phase micro-extraction (SPME) method, followed by GC-MS analysis. Chemical properties of the milk and the produced cheeses were analyzed and found not differing between the two groups. Limonene and ${\alpha}$-pinene were found in all blood and milk samples of the T group after a lag-phase of 3 d, while ${\beta}$-caryophyllene was determined only in few milk samples. Moreover, none of the terpenes were traced in blood and milk of C animals. In cheese, terpenes' concentrations presented a more complicated pattern implying that terpenes may not be reliable feed tracers. We concluded that monoterpenes can be regarded as potential feed tracers for authentification of goat milk, but further research is required on factors affecting their transfer.

• Advances in materials Research
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• 제13권3호
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• pp.161-171
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• 2024

This study aimed to investigate the effect of physicochemical properties and mix ratios of iron ore (oxide feed): coke (reductant) on the carbothermic reductions of iron ore. Coke size was fixed at ≤63 ㎛ while iron ore size varied between 150-63 ㎛ and ≤63 ㎛ respectively. Mix ratios were changed from 100:0 (reference) to 80:20 and 60:40 while the temperature, heating rate and soaking duration in muffle furnace were fixed at 1100 ℃, 10 ℃/min and 1 hour. Particle size analyzer, XRF, CHNS and XRD analyses were used for determination of raw feed characteristics. The occurrence of phase transformations from various forms of iron oxides to iron during the carbothermal reductions were identified through XRD profiles and supported with weight loss (%). XRF analysis proved that iron ore is of high grade with 93.4% of Fe₂O₃ content. Other oxides present in minor amounts are 2% Al₂O₃ and 1.8% SiO₂ with negligible amounts of other compounds such as MnO, K₂O and CuO. Composite pellet with finer size iron particles (≤63 ㎛) and higher carbon content of 60:40 exhibited 45.13% weight lost compared to 32.30% and 3.88% respectively for 80:20 and 100:0 ratios. It is evident that reduction reactions can only occur with the presence of coke, the carbon supply. The small weight loss of 3.88% at 100:0 ratio occurs due to the removal of moisture and volatiles and oxidations of iron ore. Higher carbon supply at 60:40 leads into better heat and mass transfer and diffusivity during carbothermic reductions. Overall, finer particle size and higher carbon supply improves reactivity and gas-solid interactions resulting in increased reductions and phase transformations.

• Asian-Australasian Journal of Animal Sciences
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• 제13권6호
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• pp.802-810
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• 2000

A total of 120 finishing crossbred pigs ($Landrace{\times}Large$ $White{\times}Duroc$) with equal numbers of barrows and gilts weighing 58.5 kg body weight were used in a feeding trial, and 6 pigs (three of each sex) were used in a metabolic trial to investigate the effect of phase feeding. Finishing period was divided into two phases and 4 different diets were fed for those periods. Growth performance was not significantly different among treatments within the same sex. This result showed that 16% crude protein for early finishing period and 14% crude protein diet for late finishing period should be optimum. During the early finishing period, only feed intake was significantly different between sexes (p<0.01), but in late finishing period daily weight gain (p<0.001) and feed intake (p<0.01) of barrows were significantly higher than those of gilts. During the early finishing period, digestibilities of dry matter, protein and phosphorus were significantly higher in gilts than in barrows (p<0.05). However, there was no treatment effect within same sex during the early and late finishing period. During early finishing period, excretion of N of pigs fed 16% CP diet in early and 14% CP diet in late-finishing period was less than that of pigs fed 17% CP diet in early and 15% CP diet in late-finishing period (p<0.05), but the difference was not significant. During the late finishing period, N excretion with two phase feeding was reduced by 8.5% compared with single feeding. In gilts, total cost reduction by two phase feeding compared to single feeding was 9.1%, but in barrows it was just 3.19%. Relative margin increased with two phase feeding by 2.5% in gUts and 0.2% in barrows. There was a tendency that backfat thickness at 10th rib of gilts was thinner than that of barrows (p>0.05). Within the same sexes, there was no treatment effect on back fat thickness (p>0.05). Carcass grade was improved by two phase feeding compared to single feeding. Carcass grade of gilts was significantly better than that of barrows (p<0.001). From this results, it is concluded that finishing pigs could be fed two-phase diets to improve profit and reduce pollution.

• Asian-Australasian Journal of Animal Sciences
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• 제22권2호
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• pp.267-274
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• 2009

Two experiments were conducted to investigate the feeding value of wood vinegar in weanling pigs. In Experiment 1, weanling pigs (n = 224; Landrace ${\times}$Yorkshire ${\times}$Duroc, 21${\pm}$3 d-old, initial BW 6.12${\pm}$0.10 kg) were assigned to four dietary treatments. Different levels of wood vinegar were added to the diets as dietary treatments (0, 0.1, 0.2 and 0.3%). Each treatment comprised 4 replicates with 14 piglets in each. Experimental feeding was conducted for 28 d in two phases (phase I, d 0 to 14 and phase II, d 15 to 28). Feeding of wood vinegar linearly (p<0.05) improved the phase I, phase II and overall ADG and increased (linear, p<0.05) the overall and phase II ADFI. Linear improvements in the apparent fecal digestibility of dry matter (p = 0.013), gross energy (p = 0.019) and crude protein (p = 0.033) were observed as the level of wood vinegar was increased in the diet of pigs. Experiment 2 was conducted to compare dietary wood vinegar with commonly used growth promoters, organic acid (mixture of 21% phosphoric acid, 3.25% propionic acid, 2.8% formic acid, 10% calcium formate and 5% calcium propionate) and antibiotic (aparamycin). A total of 288 weanling piglets (Landrace ${\times}$Yorkshire ${\times}$Duroc, 22${\pm}$2 d-old, initial BW 6.62${\pm}$0.31 kg) were assigned to four treatments with four replicates (18 piglets/pen) for 28 days and fed in 2 phases: phase I, d 0 to 14 and phase II, d 15 to 28. The dietary treatments were control (corn-soybean meal basal diet without antibiotics) and diets containing 0.2% antibiotic, 0.2% organic acid and 0.2% wood vinegar. Pigs fed antibiotic showed higher (p<0.001) ADG and better feed efficiency followed by pigs fed wood vinegar and organic acid diets while those fed the control diet had lowest ADG and poorest feed efficiency. The overall and phase I ADFI was highest (p<0.001) in pigs fed wood vinegar and lowest in pigs fed the control diet. Apparent fecal digestibility of dry matter, gross energy and crude protein was significantly higher (p<0.05) in pigs fed the antibiotic diet when compared with pigs fed the control but comparable among pigs fed antibiotic, organic acid and wood vinegar diets. Higher populations of Lactobacillus (p = 0.004) were noted in the ileum of pigs fed the wood vinegar diet, while the population of coliforms in the ileum and cecum was higher (p<0.001) in pigs fed the control diet when compared with pigs fed antibiotic, organic acid or wood vinegar diets. These results indicated that wood vinegar could improve the performance of weanling pigs by improving the nutrient digestibility and reducing harmful intestinal coliforms; moreover performance of pigs fed wood vinegar was superior to those fed organic acid.

• Asian-Australasian Journal of Animal Sciences
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• 제14권10호
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• pp.1419-1424
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• 2001

Previous research in our laboratory has demonstrated the importance of lactose in phase I and II pig starter diets. Two experiments were conducted to evaluate the use of a carbohydrate by-product (food by-products) as a replacement for lactose. In Exp. I, 120 weaned pigs ($14{\pm}2d$ and 5.65kg) were allotted in a randomized complete block design (RCBD) to 10 replications with four pigs per pen. This experiment evaluated three carbohydrate sources (lactose, carbohydrate by-product, and 50-50 blend of the carbohydrate by-product and lactose). The carbohydrate sources were added at 26% in the phase I diets and 15% in the phase II diets. Phase I diets contained 7.5% spray dried plasma protein (SDP). The phase I diets were fed from d 0 to 14 and the phase II diets from d 15 to 28. There were no significant differences between carbohydrate sources on pig performance in phase I. However, during phase II pigs fed the diet with lactose had an improved gain/feed ratio (G/F) (p=0.06) compared to pigs fed the carbohydrate by-product. For the entire 28 d trial ADG, ADFI and G/F were similar for the 50-50 blend and those fed lactose. Total replacement of lactose with the carbohydrate byproduct resulted in a reduced G/F (p=0.09). Exp. 2 used 100 weaned pigs ($17{\pm}2d$ and 4.75kg) with five replications with five pigs per pen. This experiment evaluated four carbohydrate treatments (lactose, carbohydrate by-products, 50-50 blend, and corn). All phase I diets contained 3.5% SDP with the carbohydrate sources included at 15%, and were fed d 0 to 14. The phase II diets contained 7.5% of the carbohydrate sources and were fed d 15 to 27. A common phase III diet was fed d 28 to 42. During all phases pigs fed com tended to have a lower ADG than pigs fed the other carbohydrate sources with the 50-50 blend resulting in the highest ADG. The results of both experiments suggest that this carbohydrate by-product can replace at least 50% of the lactose in phase I and phase II pig starter diets.

• 한국정밀공학회지
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• 제34권4호
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• pp.265-272
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• 2017

Velocity ripple in manufacturing processes reduces productivity and limits the precision of the product. In practice, the frequency and phase of velocity ripples always change minutely, which makes it impossible to compensate for the ripple by simply inserting an opposite feed-forward signal in the system. In this study, an active-phase compensation algorithm was developed to enable the velocity-ripple controller to track the phase change of the ripples in real time. The proposed controller can compensate for the velocity ripple whatever its cause, including disturbance by the torque ripple. The algorithm consists of three functional modules: the velocity-ripple extractor, the synchronized integrator, and the phase shifter. Experimental results showed that the proposed controller clearly reduces velocity ripples with phase variation.

• Journal of Power Electronics
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• 제17권4호
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• pp.1117-1126
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• 2017

The main contribution of this paper is the use of sensorless active diodes to generate the gate signals for a three-phase boost-rectifier with a self-powered control scheme. The sensorless operation is achieved making use of the gate control signals generated by the active diode schemes on each of the switching devices using a pulse width half-controlled boost rectifier modulation technique (PWM-HCBR). The proposed scheme synchronizes the gate control signals with a three phase voltage supply. Autonomous operation is obtained making use of the output DC bus to feed the control circuitry, the active diodes and the driver circuitry. The three-phase boost-rectifier is supplied by a three-phase permanent magnet electric generator powered by a solar concentrator dish with variable voltage and variable frequency conditions. Experimental results report an efficiency of up to 94.6% for 25 W and an input of 3.6 V peak per phase with 450.