• Journal of Animal Science and Technology
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• v.63 no.5
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• pp.1008-1017
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• 2021

This study was conducted to investigate the effect of different fattening periods on the growth performance, carcass characteristics, and economic traits of Holstein steers. Sixty Holstein steers (8.0 ± 0.28 months old) with an average body weight (BW) of 231.88 ± 2.61 kg, were randomly allocated to five different fattening period treatments: 20, 21, 22, 23, and 24 months (n = 12 in each treatment group). Final BW and average daily gain (ADG) did not differ among the treatment groups during the early fattening period. At the late stage of the fattening period, the final BW of steers in the 24-month treatment group (812.84 kg) was greater (p < 0.05) than that of steers in the 20-month treatment group (750.39 kg). During the same period, steers in the 20- and 21-month treatment groups had a significantly higher (p < 0.05) ADG than those in the 22-month treatment group. The highest ADG (1.36 kg/day) was found in the 20-month treatment group (1.36), followed by the 21- (1.33 kg/day), 22- (1.22 kg/day), 23- (1.21 kg/day), and 24- (1.14 kg/day) month treatment groups. The feed conversion ratio (FCR) increased as the fattening period increased, and the FCR was 12.88% lower in the 20-month treatment group than in the 24-month treatment group. However, no significant differences were detected in back-fat thickness, loin area, marbling score, and chemical characteristics (water, crude protein, and crude fat content) among the treatment groups. The composition of fatty acids including C18:0, C18:1, saturated fatty acids, unsaturated fatty acids, and poly-unsaturated fatty acids did not differ among the experimental groups. As the fattening period increased, production costs increased, resulting in a decrease in gross income. The gross income for steers in the 24-month treatment group was 35.8% and 23.5% lower than that for steers in the 20- and 21-month treatment groups, respectively. Taken together, the best performance, including the ADG, FCR, and gross income, was obtained when the fattening program of the Holstein steers lasted 20 months.

• Journal of Animal Science and Technology
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• v.62 no.6
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• pp.801-811
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• 2020

The main objective of this in vitro study was to evaluate red ginseng byproduct (RGP) as a protein resource and its effects on rumen fermentation characteristics, microflora, CO2, and CH4 production in ruminants. Four treatments for in vitro fermentation using buffered rumen fluid over a 48 h incubation period were used: 1, RGP; 2, corn gluten feed (CGF); 3, wheat gluten (WG); and 4, corn germ meal. In vitro dry matter digestibility (IVDMD), in vitro neutral detergent fiber digestibility (IVNDFD), in vitro crude protein digestibility (IVCPD), volatile fatty acids, pH, and ammonia nitrogen (NH3-N) were estimated after 48 h incubation. Gas production was investigated after 3, 6, 12, 24, 36 and 48 h. The CO2 and CH4 were evaluated after 12, 24, 36, and 48 h. A significant difference in total gas production and CO2 emissions was observed (p < 0.01) at all incubation times. CH4 production in RGP were higher (p < 0.05) than that in other treatments but a higher CH4 portion in the total gas production was observed in WG (p < 0.05) at 48 h incubation. The IVDMD, IVNDFD, and IVCPD of RGP was lower than those of other conventional ingredients (p < 0.01). The RGP had the lowest NH3-N value among the treatments (p < 0.01). The RGP also had the lowest total VFA concentration (p < 0.01), but presented the highest acetate proportion and acetate to propionate ratio among the treatments (both, p < 0.01). The abundance of Prevotella ruminicola was higher in RGP than in WG (p < 0.01), whereas RGP has lower methanogenic archaea (p < 0.01). In conclusion, based on the nutritive value, IVDMD, low NH3-N, and decreased methanogenic archaea, RGP inclusion as a protein source in ruminant diets can be an option in replacing conventional feed sources.

• Journal of Animal Science and Technology
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• v.66 no.1
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• pp.145-155
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• 2024

This study was conducted to determine the effects of amino acid (AA) supplementation in low-protein (LP) diets on growth performance and nitrogen (N) excretion. A total of 175 7-day-old Ross 308 male broilers, with a mean body weight (BW) of 165 g (standard deviation = 11.2 g), were grouped into five blocks by BW and allocated to seven treatments according to a randomized complete block design with five replicate cages at five birds per cage. Dietary treatments comprised a control diet containing 20.0% crude protein (CP) and six LP diets containing either 18.5% or 17.0% CP. These LP diets were supplemented with either no AA supplementation, indispensable AA, or both indispensable and dispensable AA (glutamic acid and glycine). Birds were fed experimental grower diets from day 7 to 21 and then commercial finisher diets until day 28. During the grower period (day 7 to 21), birds fed LP diets supplemented with indispensable AA exhibited greater (p < 0.05) BW, body weight gain (BWG), feed intake (FI), and gain-to-feed ratio (G:F) than birds fed LP diets without crystalline AA and were comparable to birds fed the control diet. During the finisher period (day 21 to 28), birds fed LP diets supplemented with indispensable AA showed greater (p < 0.05) BW than birds fed LP diets without crystalline AA, and their growth performance was comparable to birds fed the control diet. Throughout the overall period, supplementing indispensable AA in LP diets resulted in elevated (p < 0.05) BWG, FI, and G:F more than those of LP diets without crystalline AA and were comparable to those of the control diet. Supplementing indispensable AA in LP diets decreased amount and coefficient of N excretion as much as the control diet. Dispensable AA supplementation in LP diets did not influence growth performance and N excretion. In conclusion, supplementing indispensable AA in LP diets maintains growth performance and N excretion until the dietary CP lowers from 20.0% to 17.0% during the grower period. As long as dietary CP is above 17.0%, dispensable AA may not be deficient in LP diets during the grower period.

• Food Science of Animal Resources
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• v.34 no.5
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• pp.614-621
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• 2014

This study was conducted to isolate and characterize bacteriocin-producing bacteria against Clostridium perfringens (C. perfringens) from domestic animals to determine their usefulness as probiotics. Bacteriocin-producing bacteria were isolated from pig feces by the spot-on-lawn method. A total of 1,370 bacterial stains were isolated, and six were tentatively selected after identifying the inhibitory activity against the pathogenic indicator C. perfringens KCTC 3269 and KCTC 5100. The selected strains were identified as Enterococcus faecalis (E. faecalis) by 16s rRNA sequencing. Most of the isolated bacterial strains were resistant to 0.5% bile salts for 48 h and remained viable after 2 h at pH 3.0. Some E. faecalis also showed strong inhibitory activity against Listeria monocytogenes KCTC 3569, KCTC 3586 and KCTC 3710. In the present study, we finally selected E. faecalis AP 216 and AP 45 strain based on probiotic selection criteria such as antimicrobial activity against C. perfringens and tolerance to acid and bile salts. The bacteriocins of E. faecalis AP 216 and AP 45 strains were highly thermostable, showing anticlostridial activities even after incubation at $121^{\circ}C$ for 15 min. These bacteriocin-producing bacteria and/or bacteriocins could be used in feed manufacturing as probiotics as an alternative to antibiotics in the livestock industry.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.756-764
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• 2009

Provision of an optimal environment for the calf is critical to establishing the patterns of growth and development essential to allow the heifer to express its genetic potential for milk output and reproductive capacity during its productive life. Maternal nutrition during gestation is now recognised as a key to genetic programming in utero and this influence is extended through the complexity of hormones, growth factors and immunostimulants incorporated into colostrum and milk consumed by the neonatal calf. This natural process is most often disrupted as calves are weaned abruptly to maximise milk output for commercial exploitation. The key then is to accelerate the rate of maturation of the ruminal epithelium through the provision of concentrate starter rations and high quality forage, which promote VFA production. Management systems to promote these processes in Holstein Friesian cattle are well developed, however, little is known of these processes with buffalo and Bos indicus dairy cattle such as the Sahiwal. The development of methods to program the neonate to grow faster to puberty in these species will be important to improving their productivity for the dairy industries in tropical and sub-tropical environments in the future.

• Korean Journal of Poultry Science
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• v.24 no.3
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• pp.127-137
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• 1997

This study was conducted to estimate the laying performance and heterosis of Korean Native Chicken(KNC), Rhode Island Red(RIR), and KNC x RIR crossbreds A total of 1,274 female pullets were produced from KNC, RIR and RIR crossbreds in National Livestock Research Institute, Korea. The experiment was conducted for 2O~64 weeks from Jan 20. to Nov.25, 1996. The age at first egg of crossbreds were 144.1~148.7 days. The first egg weight of crossbreds was 39. 4~40.3 g, and body weights at first egg of KNC dark brown strain x RlR(DR), KNC light brown strain x RlR(LR) and KNC dark black strain x RlR(BR) were 1,943 g, 1,925 g and 2,044 g, respectively. During the laying period the average viability of crossbreds was 96.6~98.3%. The hen-day egg production of crossbreds were 111.1~113.O eggs at 40 weeks of age, and 223.5~227.5 eggs at 64 weeks of age, respectively. The hen-day egg production peaks were 78.2~80.1% in KNC, and 85.8~87.5% in crossbreds. The heterosis were estimated to be 3.61%, 9.21%, 4.78%, 2.97% and -1.63% for the first egg days, body weights at first egg, layer viability, hen-day egg production, and feed conversion ratio, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.6
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• pp.615-635
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• 1996

The animal industry must be environmentally sound to ensure its long-term sustainable growth. Livestock wastes mostly manure, can be a valuable resource as well as a potential hazard to environment. The first option of manure management is developing an 'environmentally sound' feeding program and feeds so there are less excreted nutrients that need to be managed. Once the manure is produced it can be best utilized as a fertilizer of a soil conditioner. In many countries the amount of manure that can be spread on land depends on the nutrient requirements of the crop being grown. The laws specify maximum application rates and not animal stocking rates. Farmer who reduce the N and P component of manure can release pressure on the environment without having to reduce the number of animals. There are alternative system for housing and manure treatment which generate manure that are easier to handle and have less pollutants or more economic value. Treated animal waste may also be used as a feedstuff or fuel source. Most of the options of waste management result in increased costs to implement. It is necessary to assess the economics in order to find an acceptable compromise between the increased costs and the benefit to the environment. Animal welfare is also becoming more and more of an issue and it will lead to systems where animals are kept in less confined environment. The new system will have a great impact in the waste management system in the future.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.9
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• pp.1328-1334
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• 2006

This paper aimed to study the toxicity of arsanilic acid on rat primary hepatocytes in vitro by a modification of the perfusion method. The conditions included concentrations of 0, 1.085, 10.85, 108.5, 1,085 and 10,850 mg/kg arsanilic acid in RPMI 1,640 medium at rat hepatocytes plates respectively, each group had five repeats at $37^{\circ}C$ for 48 h. The rat primary hepatocytes survival ratio, DNA Ladder, activities of glutathione peroxidase (GSH-px), superoxide dismutase (SOD) and catalase (CAT) in hepatocytes, activity of SOD in the medium and the expression of gene bax in hepatocytes were measured at 12 h, 24 h and 48 h respectively. The results showed that arsanilic acid decreased the activities of GSH-px and SOD, and increased the activity of CAT in all dosages, and affected as positive DNA ladder. Although the SOD activities of both hepatocytes and medium in 1.085 mg/L arsanilic acid were significantly lower than the base line at 12 h, CAT activity in 10.85 mg/L arsanilic acid was significantly higher than the base line at 48 h, and all of the DNA ladders were positive, which means 1.085 mg/L arsanilic acid induced apoptosis at 24 h. The gene expression of bax was significantly upregulated in 1.085 mg/L arsanilic acid or higher for 24 h.The parameters in 1,085 mg/L and 10,850 mg/L arsanilic acid had more severe changes than the others at any time indicating that these levels of arsanilic acid were toxic hazards for hepatocyte survival. It was concluded that arsanilic acid induced a dosage- and time-dependent gene expression of bax, 1.085 mg/L arsanilic acid could be involved in rat liver cell apoptosis at 24 h. Arsanilic acid as additives in livestock feed could present potential toxic implications for farm animals.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.6
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• pp.1042-1055
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• 2020

Objective: The ecosystem of an animal farm is composed of various elements, such as animals, farmers, plants, feed, soil, and microorganisms. A domesticated animal's health is largely connected with the reservoir of bacteria and viruses in animal farms. Although a few studies have focused on exploring the gut microbiome of animals, communities of microbiota and viruses in feedlots have not been thoroughly investigated. Methods: Here, we collected feces and dust samples (4 groups: cattle feces, C_F; horse feces, H_F; cattle dust, C_D; and horse dust, H_D) from cattle and horse farms sharing the same housing and investigated their microbiome/virome communities by Illumina sequencing. Results: Dust groups (C_D and H_D) showed higher microbial diversity than feces groups (C_F and H_F) regardless of animal species. From the microbial community analysis, all the samples from the four groups have major phyla such as Proteobacteria (min 37.1% to max 42.8%), Firmicutes (19.1% to 24.9%), Bacteroidetes (10.6% to 22.1%), and Actinobacteria (6.1% to 20.5%). The abundance of Streptococcus, which commonly recognized as equine pathogens, was significantly higher in the horse group (H_D and H_F). Over 99% among the classified virome reads were classified as Caudovirales, a group of tailed bacteriophages, in all four groups. Foot-and-mouth disease virus and equine adenovirus, which cause deadly diseases in cattle and horse, respectively, were not detected. Conclusion: Our results will provide baseline information to understand different gut and environmental microbial ecology between two livestock species.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.73-73
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• 2017

가축의 영양소 요구량 유지, 비육, 증체, 생산, 번식, 계절환경에 따라 달라지는 변동요인을 감안하여 하루 동안에 필요로 하는 영양소 요구량을 충족하도록 여러 종류의 사료를 혼합한 TMR(Total Mixed Ration)사료의 중요성이 커지고 있다. 이에 가축의 생산성 향상(등급 향상)과 축산농가의 영농비용 절감, 생력화를 위해 범용적으로 사용가능한 TMR플랜트의 개발이 반드시 필요하다. 본 연구에서는 사료비절감을 위한 식품부산물 발효탱크의 개발을 통해 발효탱크 밑 부분을 구성하고 있는 스위프오거와 이를 고정하면서 Z축으로 회전하는 고정부를 대상으로 하여 시각화 할 수 있는 FEM 시뮬레이션 기법을 이용하여 작업 중 적용되는 하중에 대해 충분한 구조 안전성을 가지고 있는지 해석하였다. 스위프오거의 재질은 SM45C, 작용하는 하중은 감속기의 출력량, RPM을 이용하여 토크 값을 구하고 조사료와 부산물사료가 포함된 TMR사료의 무게와 스위프오거의 단면적을 이용하여 압력 값을 도출하였다. 하지만 부산물사료가 발효되면서 저장탱크를 통해 배출되기 때문에 전체 사료 무게가 줄어 스위프오거에 작용하는 압력 또한 작아지는 것을 확인하였다. 이에 본 연구에서는 저장탱크에서 TMR사료가 배출되기 직전의 가장 높은 압력 상태를 가정하였다. 이 가정을 통해 토크 값은 $1.4N{\cdot}m$, 압력 값은 43 Mpa으로 나타났고 이를 바탕으로 구조해석을 진행하였다. 그 결과 스위프오거는 고정단 부근에서 최대 폰 미세스 응력 310 Mpa이 발생하여 구조적으로 가장 취약한 것으로 나타났다. 하지만 이는 SM45C의 항복강도인 343 Mpa 보다 낮아 안전한 것으로 분석된다. 또한 사료가 배출되면서 스위프오거에 작용하는 압력이 작아져 폰 미세스 응력도 작아지는 것으로 나타났다.