• Journal of Animal Science and Technology
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• 제62권2호
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• pp.141-158
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• 2020

Skin is a major thermoregulatory organ in the body controlling homeothermy, a critical function for climate adaptation. We compared genes expressed between tropical- and temperate-adapted cattle to better understand genes involved in climate adaptation and hence thermoregulation. We profiled the skin of representative tropical and temperate cattle using RNA-seq. A total of 214,754,759 reads were generated and assembled into 72,993,478 reads and were mapped to unique regions in the bovine genome. Gene coverage of unique regions of the reference genome showed that of 24,616 genes, only 13,130 genes (53.34%) displayed more than one count per million reads for at least two libraries and were considered suitable for downstream analyses. Our results revealed that of 255 genes expressed differentially, 98 genes were upregulated in tropically-adapted White Fulani (WF; Bos indicus) and 157 genes were down regulated in WF compared to Angus, AG (Bos taurus). Fifteen pathways were identified from the differential gene sets through gene ontology and pathway analyses. These include the significantly enriched melanin metabolic process, proteinaceous extracellular matrix, inflammatory response, defense response, calcium ion binding and response to wounding. Quantitative PCR was used to validate six representative genes which are associated with skin thermoregulation and epithelia dysfunction (mean correlation 0.92; p < 0.001). Our results contribute to identifying genes and understanding molecular mechanisms of skin thermoregulation that may influence strategic genomic selection in cattle to withstand climate adaptation, microbial invasion and mechanical damage.

• Genomics & Informatics
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• 제10권3호
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• pp.200-205
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• 2012

Although a large number of single nucleotide polymorphisms (SNPs) have been identified from the bovine genome-sequencing project, few of these have been validated at large in Bos indicus breeds. We have genotyped 192 animals, representing 5 cattle populations of Ethiopia, with the Illumina Bovine 8K SNP BeadChip. These include 1 Sanga (Danakil), 3 zebu (Borana, Arsi and Ambo), and 1 zebu ${\times}$ Sanga intermediate (Horro) breeds. The Hanwoo (Bos taurus) was included for comparison purposes. Analysis of 7,045 SNP markers revealed that the mean minor allele frequency (MAF) was 0.23, 0.22, 0.21, 0.21, 0.23, and 0.29 for Ambo, Arsi, Borana, Danakil, Horro, and Hanwoo, respectively. Significant differences of MAF were observed between the indigenous Ethiopian cattle populations and Hanwoo breed (p < 0.001). Across the Ethiopian cattle populations, a common variant MAF (${\geq}0.10$ and ${\leq}0.5$) accounted for an overall estimated 73.79% of the 7,045 SNPs. The Hanwoo displayed a higher proportion of common variant SNPs (90%). Investigation within Ethiopian cattle populations showed that on average, 16.64% of the markers were monomorphic, but in the Hanwoo breed, only 6% of the markers were monomorphic. Across the sampled Ethiopian cattle populations, the mean observed and expected heterozygosities were 0.314 and 0.313, respectively. The level of SNP variation identified in this particular study highlights that these markers can be potentially used for genetic studies in African cattle breeds.

• Asian-Australasian Journal of Animal Sciences
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• 제32권4호
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• pp.548-555
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• 2019

Objective: The main objective of this study was to evaluate the effect of different feeding levels of a total mixed ration silage-based diet on feed intake, total tract digestion, enteric methane emissions, and energy partitioning in two beef cattle genotypes. Methods: Six mature bulls (three Thai natives, and three Thai natives - Charolais crossbreeds) were assigned in a replicated $3{\times}3$ Latin square design, with cattle breed genotype in separate squares, three periods of 21 days, and three energy feeding above maintenance levels (1.1, 1.5, and 2.0 MEm, where MEm is metabolizable energy requirement for maintenance). Bulls were placed in a metabolic cage equipped with a ventilated head box respiration system to evaluate digestibility, record respiration gases, and determine energy balance. Results: Increasing the feeding level had no significant effect on digestibility but drastically reduced the enteric methane emission rate (p<0.05). Increasing the feeding level also significantly increased the energy retention and utilization efficiency (p<0.01). The Thai native cattle had greater enteric methane emission rate, digestibility, and energy utilization efficiency than the Charolais crossbred cattle (p<0.05). The daily metabolizable energy requirement for maintenance in Thai native cattle ($388kJ/kg\;BW^{0.75}$, where $BW^{0.75}$ is metabolic body weight) was 15% less than that in Charolais crossbred cattle ($444kJ/kg\;BW^{0.75}$). Conclusion: Our results suggested that the greater feeding level in zebu beef cattle fed above maintenance levels resulted in improved energy retention and utilization efficiency because of the reduction in enteric methane energy loss. The results also indicated higher efficiency of metabolisable energy utilization for growth and a lower energy requirement for maintenance in Bos indicus than in Bos taurus.

• Journal of Animal Science and Technology
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• 제44권2호
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• pp.181-190
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• 2002

본 연구는 한우 mt DNA 염기서열 가운데 $tRNA^{Pro}$와 $tRNA^{Pre}$ 유전자 사이에 위치하고 있는 D-loop 영역의 염기서열을 결정하고 한우의 염기변이 다형성을 분석하기 위하여 mt DNA의 D-loop 영역내 404번부터 15061까지 1142bp 크기의 염기서열 부위를 특이적인 primer를 이용하여 PCR로 증폭하였다. 한우의 mt DNA내 D-loop 영역에서 단일염기의 치환 및 삽입에 의해 총 24개의 polymorphic site가 확인되었다. 한우 mt DNA D-loop 영역 가운데 16042～16122번째에 위치하고 있는 영역의 염기치환율이 다른 염기서열 영역에 비하여 약 50%를 점유하고 있었으며 이들 polymorphic site에서 16055, 16230 및 16260 번의 염기치환은 한우에서만 검출된 새로운 염기변이로 확인되었다. 따라서, 한우 D-loop 영역내 특이적인 염기변이는 모계 및 세포질 DNA marker로서 한우품종을 특정하는데 활용할 수 있는 가능성을 시사하였다. Polymorphic site의 출현빈도는 169번째 염기가 81.3%로 가장 출현율이 높았고 다음으로 16302번과 16093번째는 56.3% 그리고 16042번와 16119번째 염기가 각각 50.0%와 43.8%의 치환율을 보였으며 나머지 14개 염기는 6.3%에서 25.0% 수준의 출현율을 나타냈다. 한우와 타 품종간의 유전적 근연관계를 추정한 결과 Bos taurus 계통의 유럽종과 유전적 유사도가 높은 것으로 추정되었고, Africa와 India의 Bos indicus 계통의 품종과는 상대적으로 근연관계가 먼 것으로 나타났다. 본 연구에서 검출한 mt DNA내 D-loop 영역의 염기서열 다형성은 한우집단의 유전적 변이성 추정과 모계유전 분석 및 나아가 경제적으로 중요한 형질들과의 연관성 분석에 유용하게 활용할 수 있을 것으로 기대된다.

• 생명과학회지
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• 제23권1호
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• pp.24-30
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• 2013

본 연구는 mtDNA cytochrome b (Cyt b) 유전자 서열을 토대로 한국흑우의 유전적 다양성 및 계통유전학적 위치를 파악하기 위하여 실시하였다. 한국흑우 38두로부터 결정된 mtDNA Cyt b 유전자 전체서열 내에서 염기삽입 및 결실 없이 1개의 silent mutation이 동정되었다. 또한 2개의 haplotype으로 분류되었고, 염기변이율 및 haplotype 다양성지수에 기초한 한국흑우의 유전적 다양성은 기존에 보고된 중국 품종에 비해 낮게 나타났다. 한국, 일본, 중국에 분포하고 있는 12품종 101개 서열을 수집하여 한국흑우와의 유연관계를 확인하였다. 한국흑우에서 분류된 2개의 haplotype은 모두 B. taurus 계열에 포함되었으며, 한우, 일본흑우, Yanbian, Zaosheng 등 4개 품종과 하나의 그룹을 형성하였다. 또한 품종별 Dxy 유전거리 산출 결과, 한국흑우는 한우 및 일본흑우에 비해서 중국의 Yanbian, Zaosheng 품종과 더 가까운 유연관계를 보였다. 본 연구의 결과는 가축유전자원으로서 한국흑우의 보존 및 유전적 특성 구명을 위한 중요한 자료로 활용이 가능할 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제7권1호
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• pp.131-136
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• 1994

In an effort to confirm true oestrus and to detect early pregnancy in Zebu cows (Bos indicus), sequential blood and milk samples were collected at the day of imsemination (Day 0) and days 14, 20 and 24 after insemination. Progesterone was determined in skimmed milk and plasma by solid phase radioimmunoassay (RIA). Of the cows thought to be in oestrus plasma, (n = 46) and milk (n = 58) samples demonstrated low progesterone concentrations ($0.99{\pm}0.11$ and $2.02{\pm}0.14nmol/l$) in 42 (91%) and 52 (90%) cases respectively. Thirty two (76%) and 30 (71%) cows were thought to be pregnant by plasma progesterone RIA ($20.23{\pm}1.03$ and $20.48{\pm}1.01nmol/l$) at days 20 and 24 respectively. At the same period, 40 (77%) and 37 (71%) cows were thought to be pregnant by milk progesterone RIA ($27.82{\pm}1.28$and $28.02{\pm}1.27nmol/l$). Assuming 100% accuracy for rectal examination of pregnancy diagnosis between days 60-65 postservice, the RIA was found to be 84% and 90% accurate for plasma and 84% and 92% accurate for milk at day 20 and 24, respectively. All cows thought to be non pregnant by progesterone measurement were correctly diagnosed. Progesterone assay at 24 days after oestrus may therefore be accurate for early diagnosis of pregnancy in Zebu cows.

• Asian-Australasian Journal of Animal Sciences
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• 제22권1호
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• pp.13-19
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• 2009

In the present study, genetic analyses of diversity and differentiation were performed on four breeds of Indian zebu cattle (Bos indicus). In total, 181 animals belonging to Ponwar, Kherigarh, Gangatiri and Kenkatha breeds were genotyped for 20 cattle specific microsatellite markers. Mean number of alleles observed per locus (MNA) varied between 5.75 (Kenkatha) to 6.05 (Kherigarh). The observed and expected heterozygosity for the breeds varied from 0.48 (Gangatiri) to 0.58 (Kherigarh) and 0.65 (Kenkatha) to 0.70 (Kherigarh), respectively. $F_{IS}$ estimates of all the breeds indicated significant deficit of heterozygotes being 28.8%, 25.9%, 17.7% and 17.7% for Gangatiri, Ponwar, Kherigarh and Kenkatha, respectively. The $F_{ST}$ estimates demonstrated that 10.6% was the average genetic differentiation among the breeds. Nei's genetic distance DA and Cavalli- Sforza and Edwards Chord distance ($D_C$) and the phylogenetic tree constructed from these reflected the close genetic relationship of Gangatiri and Kenkatha, whereas Ponwar appears to be more distant.

• Asian-Australasian Journal of Animal Sciences
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• 제31권7호
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• pp.961-967
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• 2018

Lao-native beef cattle are primarily Bos indicus, and most ruminant production in Laos is still dominated by small-scale or backyard producers that use traditional practices, resulting in low productivity. The cattle herd size in Laos has grown by an average of 5 percent per year from 1.52 million in 2010/11 to 1.81 million in 2014/15. In 2016, the Laos cattle population was 1.88 million head, with smallholder farmers representing 98% of production despite efforts by the Laos government to develop commercial-scale farms. There were 170 commercial cattle farms in 2016, with 56 percent in the Central region of Laos. Although, overall, ruminant meat production has tended to increase but with consumption at 7.29 kg/capita/yr in 2013, it remains insufficient to meet demand. Crop residues and agro-industrial by-products used in ruminant diets include rice straw, cassava pulp and wet brewers' grains as roughage, energy and protein sources, respectively. The Belt and Road Initiative proposed by China in 2013 will connect China closely with all countries in Southeast Asia. This initiative will change landlocked Laos to land linked for investors who will benefit from convenient transport at a lower cost, promoting agricultural production in Laos.

• Asian-Australasian Journal of Animal Sciences
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• 제16권10호
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• pp.1443-1450
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• 2003

Crossbred (Bos taurus${\times}$Bos indicus) calves were used from birth till 14 weeks of age to evaluate three sources of protein that differed in ruminal degradability viz. groundnut cake alone (HD) or in combination with cottonseed meal (MD) and meat and bone meal (LD), when fed along with two sources of non-structural carbohydrates viz. raw (R) and thermally processed (P) maize. Twenty four new born calves were arranged in six groups in a $3{\times}2$ factorial design and fed on whole milk up to 56 d of age. All the different calves received calf startes along with green oats (Avena sativa) from 14 d of age onwards free-choice. A metabolism trial of 6d starters duration, conducted after 90 d of experimental feeding, revealed greater (p<0.05) digestibility of DM, OM, total carbohydrates, NDF and ADF in calves fed on the P diets than on the R diets promoting greater (p<0.05) metabolizable energy intake. The digestibility of NDF was higher (p<0.01) on LD diets where as calves on MD diets exhibited significantly lower digestibility of ADF (p<0.01). The retention of nitrogen per unit metabolic body size was significantly (p<0.05) higher on the LD-P diet than on the diet HD-P which, in turn, was higher (p<0.05) than that of HD-R. Nitrogen retention as percentage of intake was significantly greater (p<0.05) on LD-P than on LD-R diets (52.2 vs. 36.4%). Also, P fed calves utilized nitrogen more efficiently than the R fed as shown by retention of significantly greater proportions of intake (47.4 vs. 40.9%) and absorbed (65.8 vs. 59.5%) nitrogen. Calorimetric evaluation of the diets through open-circuit respiration chamber revealed that the dietary treatments had no impact on methane production by calves. The intake of DE and ME was improved (p<0.01) because of maize processing resulting in greater (p<0.01) retention of energy. The protein degradability exerted no influence on the partitioning or retention of energy. A significant interaction between cereal and protein types was evident with respect to retention of both nitrogen (p<0.01) and energy (p<0.05). In conclusion, no discernible trend in the influence of cereal processing was apparent on the dietary protein degradability, but the positive effect of cereal processing on energy retention diminished with the increase in dietary undegradability.

• Asian-Australasian Journal of Animal Sciences
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• 제16권10호
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• pp.1455-1459
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• 2003

A $2{\times}3$ factorial design was used to study the impact of rearing systems, individual (I) vs. group (G) and different levels of milk/skim milk feeding (three schedules, F1, F2 and F3) on performance of crossbred (Bos indicus ${\times}$ Bos taurus) calves. Six calves (three from each sex) were taken in each group on the basis of their birth weight. All the calves were fed colostrum for three days and thereafter, were allotted to three different milk feeding schedules (F), i.e. milk fed upto 8 weeks of age (F1), milk upto 4 weeks followed by 50% (F2) and 100% (F3) replacement of milk with skim milk in the next 4 weeks. Calf starter and cereal green fodder were fed ad libitum to all the calves beginning from second week of age. A digestibility trial was conducted at 15th week of age to assess nutrient utilization during postweaning period. The digestibilty of dry matter (DM), organic matter, total carbohydrate, ether extract and crude protein (CP) were nonsignificant between the rearing systems and the feeding schedules. There was significantly higher digestibility of NDF and ADF in G than I and in F3 than F1 and F2. The concentration CP and total digestible nutrients of the diet ranged from 17.18 to 17.75% and 66.32 to 70.14%, respectively. The DM intake (kg/100 kg body weight) ranged from 1.74 to 2.14 kg during 0 to 8 weeks and 3.19 to 3.41 kg during 0 to 14 weeks of age. The effects during postweaning phase (9-14 weeks of age) showed increased performance in group housed calves compared to individually housed ones with a superior average daily gain (590 vs. 443 g) and dry matter intake (1.79 vs. 1.64 kg). Above all, replacement of milk with skim milk at 50% level after 4th week followed by complete removal after 6th week of age (F2) seemed to suit better in coping with immediate energy starvation due to sole feeding of skim milk (F3) and they performed the best under group housed system of rearing.