• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.1
• /
• pp.74-81
• /
• 2010

The effects of different levels of natural clay enterosorbent on the growth, nutrient availability, and genital organs of post-weaning female pigs fed with an addition of zearalenone (ZEA) were investigated in the study. A total of thirty-five post-weaning gilts ($L{\times}Y{\times}D$) with an average body weight of 12.36${\pm}$1.46 kg were used in the test. The gilts were raised individually in metabolism cages and fed a corn-soybean meal-whey basal diet with an addition of 0 or 1 mg/kg of ZEA for 24 d with four levels of natural clay enterosorbent added in the feed. The treatments were: i) control; ii) control+2.5 g/kg clay; iii) control+1 mg/kg ZEA; iv) control+1 mg/kg ZEA+1.25 g/kg clay; v) control+1 mg/kg ZEA+2.5 g/kg clay; vi) control+1 mg/kg ZEA+5.0 g/kg clay; vii) control+1 mg/kg ZEA +10 g/kg clay. Pigs fed diets contaminated with additional purified ZEA had significantly reduced apparent digestibility of crude protein (CP), gross energy (GE) and apparent metabolic rate of GE (ME/GE, p<0.05) without changes of net protein utilization (NPU, p>0.05). Final body weight, average daily gain (ADG), average daily feed intake (ADFI), vulva length, vulva width, vulva area, relative weights of genital organ and proliferative changes of the ovary tissues in gilts fed ZEA-contaminated diet were increased (p<0.05) compared to the gilts fed the control diet. Addition of natural clay enterosorbent in the ZEA-contaminated diet showed a positive protection effect on ZEA feeding, and the protection was increased linearly or quadratically as clay content increased. However, in pigs fed a diet with clay alone at 2.5 g/kg level there was no significant impact (p>0.05) on all the parameters as compared to the control. It is suggested that feeding ZEA at about 1.0 mg/kg for 24 days might result in a deleterious effect in pigs, and addition of 5 or 10 g clay enterosorbent per kg diet can effectively neutralize the detrimental effects of the ZEA feeding.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.6
• /
• pp.898-907
• /
• 2005

Chromium has emerged as an essential trace mineral in nutrition. However, it readily causes toxicity because of slightly excessive dose and/or form of chromium supplement. Therefore, developing a noble form of chromium supplement which is capable of not only an increased availability but also a reduced toxicity has been a critical issue in chromium nutrition. Chromium-methionine chelate has been, so far, one of the latest developments in its kind. Although not much information is available for the chromium-methionine chelate, especially in view of animal performances upon dietary supplementation, several studies indicated chromium methionine chelate could be effective to improve meat quality by increasing muscle mass but decreasing body fat. Highly-graded beef was produced by dietary chromium methionine supplementation during fattening stage of Korean native steers. Body muscle was increased in replace of decreasing body fat in both pig and rat that were dietary supplemented with chromium methionine chelate. However, a pig farm study did not show any significant improvement of body gain upon supplementation of chromium methionine. Immune responses of pig and rat were not always dependent upon chromium form but were varied by species. These results suggest there could be a different mode of responses due to species as well as onset time of dietary supplementation of chromium methionine. It is still early to conclude the bio-efficacy of chromium methionine chelate presumably due to its recent appearance into the field. But the chelate is certainly worth more application to animal since it certainly reduced the application level of dietary chromium.

• Fisheries and Aquatic Sciences
• /
• v.11 no.4
• /
• pp.190-194
• /
• 2008

We estimated the digestibility and growth rate of juvenile olive flounder (Paralichthys olivaceus) on three diets: raw fish-based moist pellets, moist pellets, and extruded pellets. The diets were created using commercially available methods, and a basic formulated powder. A reference diet was used to compare feed digestibility and the fish growth rate achieved using the experimental diets. The apparent digestibility coefficients (ADCs) of protein for raw fish-based moist pellets and moist pellets were significantly higher (P<0.05) than those for extruded pellets and the reference diet. The ADCs of nitrogen-free extracts (NFE) of extruded pellets and moist pellets were significantly higher (P<0.05) than those for raw fish-based moist pellets and the reference diet. Fish that were fed with the raw fish-based moist pellets showed the greatest weight gain (452.4%), which was not significantly different from that of fish fed with extruded pellets (414.4%; P>0.05). These results indicate that the higher protein efficiency in fish fed with extruded pellets can result in good growth performance within flounder culture systems.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.3
• /
• pp.419-428
• /
• 2019

Phytases are enzymes that can hydrolyze phytate and its salts into inositol and phosphoric acid, and have been utilized to increase the availability of nutrients in animal feed and mitigate environmental pollution. However, the enzymes' low thermostability has limited their application during the feed palletization process. In this study, a combination of B-value calculation and protein surface engineering was applied to rationally evolve the heat stability of Escherichia coli phytase. After systematic alignment and mining for homologs of the original phytase from the histidine acid phosphatase family, the two models 1DKL and 1DKQ were chosen and used to identify the B-values and spatial distribution of key amino acid residues. Consequently, thirteen potential amino acid mutation sites were obtained and categorized into six domains to construct mutant libraries. After five rounds of iterative mutation screening, the thermophilic phytase mutant P56214 was finally yielded. Compared with the wild-type, the residual enzyme activity of the mutant increased from 20% to 75% after incubation at $90^{\circ}C$ for 5 min. Compared with traditional methods, the rational engineering approach used in this study reduces the screening workload and provides a reference for future applications of phytases as green catalysts.

• Korean Journal of Agricultural Science
• /
• v.50 no.4
• /
• pp.653-661
• /
• 2023

Phytase enhances phosphorus availability in pig diets by breaking down phytic acid, which is challenging for animals to digest. This study aimed to assess the impact of dietary phytase supplementation on the growth performance, nutrient digestibility, and fecal score of growing pigs. Sixty-four growing pigs ([Yorkshire × Landrace] × Duroc, average body weight 21.20 ± 0.18 kg) were randomly assigned to one of two treatment groups. The dietary treatments were CON, basal diet, and PHY, basal diet + 0.0025% phytase. Results indicated a tendency for increased average daily gain in the phytase-supplemented diet group (p < 0.10) compared to the control diet group. The average daily feed intake and feed conversion ratio were not affected by the addition of 0.0025% phytase. Furthermore, dry matter digestibility, nitrogen content, and digestible energy were not influenced (p > 0.05) by phytase supplementation. Fecal score remained similar (p > 0.05) in growing pigs fed phytase-supplemented and control diets. These findings suggest that supplementing the diet of growing pigs with 0.0025% phytase may lead to improved average daily gain without adverse effects on nutrient digestibility and fecal score. This implies the potential to enhance growth performance without compromising overall health or digestion in pigs. Further investigations into the optimal levels of phytase supplementation for growing pigs are recommended.

• Journal of Microbiology and Biotechnology
• /
• v.34 no.5
• /
• pp.1119-1125
• /
• 2024

Phytase increases the availability of phosphate and trace elements by hydrolyzing the phosphomonoester bond in phytate present in animal feed. It is also an important enzyme from an environmental perspective because it not only promotes the growth of livestocks but also prevents phosphorus contamination released into the environment. Here we present a novel phytase derived from Turicimonas muris, TmPhy, which has distinctive structure and properties compared to other previously known phytases. TmPhy gene expressed in the Pichia system was confirmed to be 41 kDa in size and was used in purified form to evaluate optimal conditions for maximum activity. TmPhy has a dual optimum pH at pH3 and pH6.8 and exhibited the highest activity at 70℃. However, the heat tolerance of the wildtype was not satisfactory for feed application. Therefore, random mutation, disulfide bond introduction, and N-terminal mutation were performed to improve the thermostability of the TmPhy. Random mutation resulted in TmPhyM with about 45% improvement in stability at 60℃. Through further improvements, a total of three mutants were screened and their heat tolerance was evaluated. As a result, we obtained TmPhyMD1 with 46.5% residual activity, TmPhyMD2 with 74.1%, and TmPhyMD3 with 66.8% at 80℃ heat treatment without significant loss of or with increased activity.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.3
• /
• pp.363-367
• /
• 2006

The nutritional worth of Phalaris minor seeds was assessed in comparison to conventional cereal grains like maize and wheat. P. minor seeds had higher total ash and cell wall constituents as compared to wheat and maize grains. The CP content of P. minor was comparable to wheat grains but higher than maize grains. The in vitro studies revealed that the net gas production and availability of ME from P. minor was comparable to that of maize but the digestibility of nutrients was significantly (p<0.05) lower than that of conventional cereal grains. The digestion kinetic parameters for DM and CP revealed that P. minor had the highest (p<0.05) soluble fraction (a) followed by wheat and maize. Reverse trend was observed for insoluble but potentially degradable fraction (b). The effective and true DM and CP degradability was significantly (p<0.05) higher in wheat grains followed by that in P. minor and maize grains. The digestibility of OM and NDF was not affected by replacing cereal grains in concentrate mixture with P. minor seeds up to 75 per cent level. But the availability of ME from concentrate mixtures was comparable to control only up to 50% level of replacement. Replacement of cereal grains with P. minor did not affect the rapidly soluble fraction and insoluble but potentially degradable fraction of concentrate mixture containing P. minor up to 75 per cent, but it was depressed significantly at 100% replacement level. The effective and true degradability of DM of concentrate mixtures containing P. minor from 50 to 100 per cent was comparable to that of conventional concentrate mixture (CCM). The wheat based concentrate mixtures showed higher net gas production (208 vs. 201 ml/g DM/24 h), digestibility of nutrients and ME availability (9.64 vs. 9.54 MJ/kg DM) as compared to maize based concentrate mixture. The wheat based concentrate mixture had significantly (p<0.05) higher rumen undegradable fraction and effective degradability. The data conclusively revealed that conventional cereal grains could be replaced with P.minor seeds up to 75 per cent without affecting the availability of nutrients.

• Korean Journal of Poultry Science
• /
• v.31 no.4
• /
• pp.265-271
• /
• 2004

A feeding trial was conducted to investigate the influence of feeding Lactobacillus reuteri culture (LR) on productive performance, intestinal microflora and availability in laying hens. Four hundred and eighty, Isa-Brown layers, 49 weeks of age, were fed diets supplemented with LR at the level of 0 (control), 0.1, 0.2, and $0.4\%$ of the diets for eight weeks. Egg production and egg weight were measured daily. Feed intake was weighed every two weeks. Egg quality was measured three times at the start, mid-term, and end of the experiment. Intestinal microflora were examined for Lactobacillus spp., E. coli and Salmonella at the end of the experiment. Overall egg production was the highest in $0.2\%$ LR (P<0.05), but that of $0.1\%$ or $0.4\%$ LR treatments did not significantly differ from that of control. Egg weight was significantly higher in LR feeding group than the control (P<0.05). Daily egg mass was significantly higher in $0.2\%$ and $0.4\%$ LR treatments compared to the control and $0.1\%$ LR (P<0.05). The number of jumbo and extra large eggs were increased in LR supplemented groups, especially in $0.1\%$ LR. Feed intake of layers fed LR supplemented diets tended to be lower than the control. However, feed conversion ratio significantly improved in LR supplemented groups (P<0.05). Availability of dry matter and crude protein improved significantly in $0.4\%$ LR treatment (P<0.05). But, those of ether extract and crude ash were not significantly different among treatments. Eggshell breaking strength and eggshell thickness were not significantly influenced by LR supplementation, and Haugh unit and yolk index were also similar to the control. Total number of Lactobacillus spp. in ileum and cecum fed LR supplemented diets were significantly higher than those of the control (P<0.05). There were no significant differences in intestinal E. coli and Salmonella in all treatments. Therefore, it is concluded that dietary supplementation of Lactobacillus reuteri culture can improve the laying performance, feed efficiency and intestinal Lactobacillus.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.2
• /
• pp.471-477
• /
• 2012

SCM420 steel tempered after performing gear hove PACVD carbide coating on the surface after the cutting surface hardness was high. Difficult-to-cut, without coating is classified as mild as large, including materials like mild, high strength that improves tool life and productivity have limited availability. Drive to improve it in the TiCN-coated carbide call for war to the finish coating on cutting a hob skiving good workability, tool wear less, 2.5-fold increase in tool life results were obtained. Experiments using CNC Skiving hobbing machine with wet cutting conditions, cutting speed and feed rate to apply a variety of the tool wear and surface roughness data were obtained. Results from condition 2 (V = 200m/min F = 0.7mm/rev) cutting speed feed mark the cutting surface microstructure and surface roughness Rmax $4.7{\mu}m$(Ra $1.19{\mu}m$) of the data was obtained.

• Microbiology and Biotechnology Letters
• /
• v.31 no.4
• /
• pp.435-438
• /
• 2003

Iron required by all organisms is related with diverse biological processes. Most eukaryotes need extra iron to maintain their nutrition balance. However, extra iron supplement gives many problem to solubility in the cells. To increase the bio-availability of iron in cells, yeast was applied to carry the iron with solubility. Selection of yeast mutants with enhanced iron uptake were performed by mutagenesis using the alkylation agent EMS. Eleven mutant strains with enhanced iron uptake were selected by the measurement of iron content with atomic absorption spectrometer. The iron content in mutants was 1.5- to 2.5-fold more than that in wild-type. These mutants could be served as iron-fortified nutrients for food and feed.