• Title/Summary/Keyword: sexual selection

Search Result 67, Processing Time 0.029 seconds

Nutrition-induced Changes of Growth from Birth to First Calving and Its Impact on Mammary Development and First-lactation Milk Yield in Dairy Heifers: A Review

  • Lohakare, J.D.;Sudekum, K.H.;Pattanaik, A.K.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.25 no.9
    • /
    • pp.1338-1350
    • /
    • 2012
  • This review focuses on the nutritional effects from birth until age at first calving on growth, mammary developmental changes, and first-lactation milk yield in heifer calves. The advancement in the genetic potential and the nutritional requirements of the animals has hastened the growth rate. Genetic selection for high milk yield has suggested higher growth capacity and hence increasing nutritional inputs are required. Rapid rearing by feeding high energy or high concentrate diets not only reduces the age of sexual maturity but also lowers the time period of attaining the age of first calving. However, high energy diets may cause undesirable fat deposition thereby affecting future milk yield potential. Discrepancies exist whether overfed or overweight heifers at puberty can influence the mammary development and future milk yield potential and performance. The data on post-pubertal nutritional management suggested that body weight at calving and post-pubertal growth rate is important in first lactation milk yield. There is a continuous research need for strategic feeding that accelerates growth of dairy heifers without reduction in subsequent production. Nutritional management from birth, across puberty and during pregnancy is critical for mammary growth and for producing a successful cow. This review will mostly highlight studies carried out on dairy breeds and possible available opportunities to manipulate nutritional status from birth until age at first calving.

Genetic Diversity and Population Structure of Glehnia littoralis (Umbelliferae) in Korea

  • Huh Man Kyu;Choi Joo Soo;Huh Hong Wook;Choi Yung Hyun;Choi Byung Tae
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.17 no.6
    • /
    • pp.1519-1523
    • /
    • 2003
  • Glehnia littoralis Fr. Schmidt (Umbelliferae) is a short-lived herbaceous species that are mostly distributed throughout East Asia. Although G. littoralis has been regarded as ecologically important one, there is no report on population structure in Korea. Starch gel electrophoresis was used to investigate the allozyme variation and genetic structure of Korean populations of this species. A high level of genetic variation was found in G. littoral is populations. Nine enzymes revealed 18 loci, of which 12 were polymorphic (66.7%). Genetic diversity at the species and population levels were 0.159 and 0.129, respectively. The sexual and asexual reproduction, high fecundity, and colonization process are proposed as possible factors contributing to genetic diversity. An indirect estimate of the number of migrants per generation (Nm = 1.45) indicated that gene flow was not extensive among Korean populations of this species. It is suggested that the ability of vegetation and artificial selection may have played roles in shaping the population structure of this species. we recommend that a desirable conservation population should be included at least 30 plants per population and especially those with high variation.

Variation and Sex-limited Expression of Fluorescent Color by Ultraviolet Spectrum on the Silkworm Cocoon (누에고치의 분광성에 관한 계통별 변이 및 한성적 발현)

  • 한명세
    • Journal of Sericultural and Entomological Science
    • /
    • v.39 no.1
    • /
    • pp.22-29
    • /
    • 1997
  • Ultraviolet weavelength (UV) of 366 nm produced clearer fluorescent dolor than that of 254 nm for the inspection of silkworm cocoons. Fluorescent color of silkworm cocoons varied in color, appears no relationship with the natural color under the normal light. Uniformity of fluorescent color was improved by selection of blue or yellow line from wild types. Blue and yellow, located at the opposite poles on the color solid and L*a*b* color system, confirmed as pure standard of fluorescent color in the silkworm races for commercial white cocoons. the cocoons with blue fluorescence occupied as high as 1.7 to 8.6 times than those with yellow in the Japanese silkworm races. Fluorescence of silkworm cocoon was not affected by forced flow dry at 70$^{\circ}C$ for 6 hrs. While the Japanese races revealed no sexual difference in fluorescent color, sex-dependence of the color was common in the Chinese races for commercial white cocoon. The fluorescence of cocoon shell of Chinese races showed clear separation of blue of median color. Silkworm strain of Dc20 and Fc24 were sexualy segregated 98.8${\pm}$1.20%, 99.0${\pm}$1.00% by cocoon fluorescence, as that of 99.3${\pm}$0.44% by typical larval marking of sex-limited inheritance. Specific expression of cocoon fluorescence, applicable to breeding of simple discrimination of sex for Chinese races, inspected thoroughly on the surface and inner layer of cocoon shell.

  • PDF

Comparison of the complete chloroplast genome sequence of Solanum stoloniferum with other Solanum species generates PCR-based markers specific for Solanum stoloniferum (엽록체 전장유전체 정보를 이용한 감자 야생종 Solanum stoloniferum 구별 분자 마커 개발)

  • Kim, Soojung;Park, Tae-Ho
    • Journal of Plant Biotechnology
    • /
    • v.47 no.2
    • /
    • pp.131-140
    • /
    • 2020
  • Solanum stoloniferum, one of the wild tetraploid Solanum species belonging to the Solanaceae family, is an excellent resource for potato breeding owing to its resistance to several important pathogens. However, the sexual hybridization of S. stoloniferum with S. tuberosum (potato) is hampered due to the sexual incompatibility between the two species. To overcome this and introgress the various novel traits of S. stoloniferum in cultivated potatoes, cell fusion can be performed. The identification of the fusion products is crucial and can be achieved with the aid of molecular markers. In this study, the chloroplast genome sequence of S. stoloniferum was obtained by next-generation sequencing technology, and compared with that of six other Solanum species to identify S. stoloniferum-specific molecular markers. The length of the complete chloroplast genome of S. stoloniferum was found to be 155,567 bp. The structural organization of the chloroplast genome of S. stoloniferum was similar to that of the six other Solanum species studied. Phylogenetic analysis of S. stoloniferum with nine other Solanaceae family members revealed that S. stoloniferum was most closely related to S. berthaultii. Additional comparison of the complete chloroplast genome sequence of S. stoloniferum with that of five Solanum species revealed the presence of six InDels and 39 SNPs specific to S. stoloniferum. Based on these InDels and SNPs, four PCR-based markers were developed to differentiate S. stoloniferum from other Solanum species. These markers will facilitate the selection of fusion products and accelerate potato breeding using S. stoloniferum.

Field Studies on the Sex Attraction of the Fall Webworm Moths(Hyphantria cunea D.) and the Development of Sex-Attractant Trap (흰불나방의 성유인과 Trap형에 관한 연구)

  • Choi Seung Yoon;Song Yu Han
    • Korean journal of applied entomology
    • /
    • v.9 no.2
    • /
    • pp.85-90
    • /
    • 1970
  • This study was conducted to find out the evidence of a sex attraction in the fall webworm moths, Hyphantria cunea D., in the fold conditions. The study dealt with the sex attraction between the sexes, selection of effective trap type, effect of moth age on the sex attractiveness, sex attractiveness after copulation, and the time of the sex attraction in the day, The trap was baited with a living moth in the cylindrical screened case 4cm. in long and 2.7cm in diameter. The traps were attached on the tree in a horizontal position at the height of about 3m. on the ground. A sex pheromone was evident in the female moth which attracted the male to the lure, and the modified sticky trap was most effective in this experiment. The trap consisted of a cylindrical powder milk can 11.5cm. in long and 10cm. in diameter with the entry hole 4.8cm, in diameter at both ends of the can, and the inside of can was lined with paper coated with acri-soil(sodium poliacrilate) to catch them. Males were mostly attracted to females during their first 2 days of life, and its attractiveness decreased with moth age, No males were attracted to females more than five days old, and no females lived for more than six days. After copulation, sexual attractiveness was decreased swiftly, Sexual attractiveness was found to be greatest between 4 and 6 A.M. Living females can be used as effective baits for luring the males to the fold trapt.

  • PDF

Visualized Determination for Installation Location of Monitoring Devices using CPTED (CPTED기법을 통한 모니터링 시스템 설치위치 시각화 결정법)

  • Kim, Joohwan;Nam, Doohee
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.15 no.2
    • /
    • pp.145-150
    • /
    • 2015
  • Needs about safety of residents are important in urbanized society, elderly and small-size family. People are looking for safety information system and device of CPTED. That is, Needs and Installations of CCTV increased steadily. But, scientific analysis about validity, systematic plan and location of security CCTV is nonexistent. It is simply put these devised in more demanded areas. It has limits to look for safety of residents by increasing density of CCTVs. One of the characteristics of crime is clustering and stong interconnectivity. So, exploratory spatial data of crime is geo-coded using 2 years data and carried out cluster analysis and space statistical analysis through GIS space analysis by dividing 18 variables into social economy, urban space, crime prevention facility and crime occurrence index. The result of analysis shows cluster of 5 major crimes, theft, violence and sexual violence by Nearest Neighbor distance analysis and Ripley's K function. It also shows strong crime interconnectivity through criminal correlation analysis. In case of finding criminal cluster, you can find criminal hotspot. So, in this study I found concept of hotspot and considered technique about selection of hotspot. And then, selected hotspot about 5 major crimes, theft, violence and sexual violence through Nearest Neighbor Hierarchical Spatial Clustering.

The effects of storytelling techniques in the sex education on sound sexual value of Middle school students - Focused on the contents of the unit of 'Understanding of Adolescents' in Technology.Home Economics Textbook in Middle School - (스토리텔링 기법을 적용한 성교육이 중학생의 건강한 성가치관 형성에 미치는 효과 - 기술.가정 교과 '청소년의 이해' 단원을 중심으로 -)

  • Kang, So-Jeong;Cho, Byung-Eun
    • Journal of Korean Home Economics Education Association
    • /
    • v.25 no.1
    • /
    • pp.15-36
    • /
    • 2013
  • This study aimed to identify the effects of using storytelling techniques in sex education, in which students are encouraged to talk about their experiences with sex and love and helps them form their own sex values and decision-making skills related to sex. A five-period teaching-learning plan covering issues including safe, considerate and responsible sex was developed using the storytelling technique for 134 first-year students in 4 classes. 134 questionnaires were administrated through pre-and post-test and 38 worksheets applying a variety of storytelling activities were analyzed using content analysis. Students were found to have gained a more positive outlook on relationships and a considerate attitude towards others in sex. There was also a significant increase in items considering safe sex, including perceptions on contraception methods and selection of safe contraception methods. The students' sense of sexual responsibility was also enhanced. Results of content analysis found students to have shifted to sex focusing on love and responsibility, and to have grown a stronger sense of responsibility in their relationships. Furthermore, the respondents expressed interest in selecting proper contraception methods and held strongly negative perceptions about abortion.

  • PDF

Genetic correlations between behavioural responses and performance traits in laying hens

  • Rozempolska-Rucinska, Iwona;Zieba, Grzegorz;Kibala, Lucyna;Prochniak, Tomasz;Lukaszewicz, Marek
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.30 no.12
    • /
    • pp.1674-1678
    • /
    • 2017
  • Objective: The aim of the study was to evaluate genetic correlations between the behavioural profile and performance in laying hens as an indirect answer to the question whether the observed behavioural responses are associated with increased levels of stress in these birds. Methods: The assessment of birds' temperament was carried out using the novel objects test. The behavioural test was conducted in two successive generations comprising 9,483 Rhode Island White (RIW) birds (approx. 4,700 individuals per generation) and 4,326 Rhode Island Red (RIR) birds (approx. 2,100 individuals per generation). Based on the recorded responses, the birds were divided into two groups: a fearful profile (1,418 RIW hens and 580 RIR hens) and a brave/curious profile (8,065 RIW hens and 3,746 RIR hens). The birds were subjected to standard assessment of their performance traits, including SM, age at sexual maturity; ST, shell thickness; SG, egg specific gravity; EW, mean egg weight; IP, initial egg production; and HC, number of hatched chicks. The pedigree was three generations deep (including two behaviourrecorded generations). Estimation of the (co)variance components was performed with the Gibbs sampling method, which accounts for the discrete character of the behavioural profile denotation. Results: The analyses revealed negative correlations between the performance traits of the laying hens and the behavioural profile defined as fearful. In the group of fearful RIW birds, delayed sexual maturation (0.22) as well as a decrease in the initial egg production (-0.30), egg weight (-0.54), egg specific gravity (-0.331), shell thickness (-0.11), and the number of hatched chicks (-0.24) could be expected. These correlations were less pronounced in the RIR breed, in which the fearful birds exhibited a decline in hatchability (-0.37), egg specific gravity (-0.11), and the number of hatched chicks (-0.18). There were no correlations in the case of the other traits or they were positive but exhibited a substantial standard error, as for the egg weight. Conclusion: To sum up the results obtained, it can be noted that behavioural responses indicating fearfulness, i.e. escape, avoidance, and approach-avoidance may reflect negative emotions experienced by birds. The negative correlations with performance in the group of fearful hens may indirectly indicate a high level of stress in these birds, especially in the white-feathered birds, where stronger performance-fearfulness correlations were found. Fearful birds should be eliminated from breeding by inclusion of the behavioural profile in the selection criterion in the case of laying hens.

Mesh Selectivity of Beam Trawl for Shrimps (새우조망의 망목선택성)

  • Oh, Taek-Yun;Cho, Young-Bok;Park, Gwang-Jei;Jeong, Sun-Beom;Kim, Min-Seok;Kim, Hyeong-Seok;Lee, Ju-Hee
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.40 no.1
    • /
    • pp.86-94
    • /
    • 2004
  • This study was conducted to mesh selectivity of Beam trawl for shrimps fishing experiment in the coastal waters around Geomundo, South sea of Korea, during from Oct. to Nov. 2002. The selectivity parameters of big head shrimp (Solenocera melantho) have been studied on the covered con-end method. with mesh of 8, 38, 51 and 61 mm. Selection curves and selection parameters were calculated by using a logistic function S=1/(1+exp-(aCL+b)). The mesh selection master curves were estimated by S=1/(1+exp$^{({\alpha}(CL/M)+{\beta}}$), and the optimum mesh size were calculated with (L/M)50 of master curve. Optimum mesh size and selectivity master curves for the southern rough shrimp (Yrachysalambria curvirostris) and smoothshell shrimp (Parapenaeopsis tenella) optimum mesh size and selectivity master curves were estimated by big head shrimp master curves. The results obtained are summarized as follows : Selection parameters '${\alpha}$' and '${\beta}$' of the master curve for big head shrimp were 8.84 and -5.89, and The selection factor of the master curve (L/M)$_{50}$ was 0.67. The optimum mesh size of minimum length for sexual maturity for big head shrimp was 30.7 mm. Estimated (L/M)$_{50}$ for southern rough shrimp and smoothshell shrimp by using the master curve of big head shrimp was 0.73 and the optimum mesh sizes were 25.5 mm for southern rough shrimp and 16.9 mm for smoothshell shrimp, respectively.

A comparison of five Korean snake species' reproductive organ sizes, Oocatochus rufodorsatus and Rhabdophis tigrinus in Colubridae and Gloydius saxatilis, G. brevicaudus and G. ussuriensis in Viperidae

  • Lee, Heon-Joo;Kim, Ja-Kyeong;Kim, Il-Hun;Koo, Kyo-Sung;Park, Jaejin;Kwon, Se-Ra;Park, Daesik
    • Journal of Ecology and Environment
    • /
    • v.38 no.4
    • /
    • pp.477-483
    • /
    • 2015
  • Characteristics of snake reproductive organs that are relatively less affected by external environmental conditions can be used as an important means of classification; additionally, such characteristics can provide useful information on a species' reproductive system. In this study, we compared the testis weights, hemipenis lengths and retractor muscle lengths of male Oocatochus rufodorsatus and Rhabdophis tigrinus in Colubridae and Gloydius saxatilis, G. brevicaudus and G. ussuriensis in Viperidae. The snake snout-vent lengths (SVLs) were positively related to the three reproductive organ sizes, but the body weight only exhibited a positive relationship with the testis weight. The three organs did not significantly differ on the left and right sides. The relative testis weights and retractor muscle lengths (divided by the body weight and SVL, respectively) of the Colubridae snakes were greater than for the Viperidae snakes, but the relative hemipenis lengths (divided by SVL) did not differ between the two groups. The relative testis weight of G. saxatilis and the relative retractor muscle lengths of the Viperidae snakes were smaller compared with the Colubridae snakes. The relative hemipenis length of O. rufodorsatus was greater than for R. tigrinus, G. saxatilis and G. brevicaudus. Additional comparisons were not significant. Our results may facilitate further studies on hemipenial morphology and mating competition in Korean snakes. This is the first study on Korean snake reproductive organs.