• Title/Summary/Keyword: Tropics

Search Result 173, Processing Time 0.023 seconds

Breeding Prolific Garole with Malpura Sheep for In creased Reproductive Efficiency in Semi Arid Tropics of India

  • Sharma, R.C.;Arora, A.L.;Mishra, A.K.;Kumar, S.;Singh, V.K.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.17 no.6
    • /
    • pp.737-742
    • /
    • 2004
  • Garole, a prolific small sized sheep breed of West Bengal, was introduced in the Mutton project of the Institute in 1997 to explore the possibility of incorporating fecundity gene(s) into monotocus Malpura sheep of Rajasthan. Results of reproduction and production traits in respect of Garole${\times}$Malpura (G${\times}$M) half-breds have been obtained. Of 35 lambing obtained so far from the ewes of Garole${\times}$Malpura, 45.71% were twin lambing, whereas, Malpura sheep produced mostly single lamb except 2.55% twin lambing on an average. Other reproduction traits in G${\times}$M ewes such as lambing rate, litter size at birth and weaning were considerably improved over Malpura ewes. Results revealed that the fecundity genes responsible for increasing ovulation rate and litter size have been incorporated in to the G${\times}$M genotype and it might prove a valuable germ plasm towards evolving a new prolific strain of sheep. Interestingly, survivability of G${\times}$M half-breds was almost at par with the local Malpura sheep in harsh climatic conditions of semi-arid tropics. The body weights at different ages of G${\times}$M half-breds were on little lower side compared to contemporary Malpura lambs. Average kilogram of lambs weaned/ewe lambed in Malpura and G${\times}$M genetic group was 11.86 and 11.07 kg respectively. In view of minimizing the differences in body weights and kg of lambs weaned/ewe lambed between the two genetic groups, G${\times}$M ewes has to be backcrossed with Malpura rams to raise the inheritance of latter up to 75% level. However, further research is needed to reach on certain conclusions regarding net returns from such crosses.

Heterosis and Percent Improvement in Survivability, Reproduction and Production Performance of Various Genetic Groups of Temperate x Zebu Crosses in Tropics

  • Singh, Kuldeep;Khanna, A.S.;Sangwan, M.L.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.16 no.6
    • /
    • pp.794-799
    • /
    • 2003
  • A study was conducted on 2102 records of 808 crossbred cows of various genetic groups maintained under 'All India Coordinated Research Project on Cattle' at C C S Haryana Agricultural University, Hisar, over 25 years period (1968-1993) with an objective to assess and compare the amount of percent improvement and heterotic effect for different performance traits in various genetic groups produced under this programme. Survivability sharply and significantly declined from 1/2 to $3/4^th$ bred and further from $3/4^th$ to inter-se bred. This may be due to periodic and management differences in addition to the higher level of exotic inheritance and decreased heterotic effect over the filial generations. Jersey and Holstein Friesian crosses among 1/2 breds and their 50% inheritance among $3/4^th$ and inter-se breds had highest improvement and heterosis in reproduction and production traits respectively. Among inter se bred genetic groups, BFH (I) had no recombination loss in SP and CI, while FJH (I), JFH (I) and FBH (I) had on recombination loss in AFC, LY, LL and PE. The crossbreeding of zebu cows with exotic breeds brings about spectacular improvement in comparison to the performance of zebu breed, while conventional selection over several generation would lead to only modest improvement. In addition to additive effect, there was sufficient heterosis in Jersey crosses for reproduction and Holstein Friesian crosses for production performance. Three breed crosses with exotic inheritance between 50 and 75 percent incorporating genes (25 to 50%) from both of these breeds is the best combination for stabilization.

Forest Floor Biomass, Litterfall and Physico-chemical Properties of Soil along the Anthropogenic Disturbance Regimes in Tropics of Chhattisgarh, India

  • Oraon, P.R.;Singh, Lalji;Jhariya, Manoj Kumar
    • Journal of Forest and Environmental Science
    • /
    • v.34 no.5
    • /
    • pp.359-375
    • /
    • 2018
  • The long term ecological effects have been reported in natural forest ecosystem due to various anthropogenic disturbances, especially in tropics of the world. The present study was carried out in the sanctuary area of central India to assess the changes on litter biomass, litterfall pattern and soil attributes under different disturbance regimes. The study area includes three forest circles i.e., Bhoramdeo, Jamunpani and Salehwara each comprising three disturbances regimes viz., high, medium and low severity of biotic pressure. A noticeable variation and impact were recorded in different sites. The impact varies significantly from least disturbed sites to highly disturbed sites across the circle and among different disturbances level. The seasonal mean total forest floor biomass across the forest circles varied from 2.18 to $3.30t\;ha^{-1}$. It was found highest under lightly disturbed site and lowest under heavily disturbed site. Total litterfall varied from 5.11 to $7.06t\;ha^{-1}\;yr^{-1}$ across the forest circle. Lowest litterfall was recorded at heavily disturbed site while highest in lightly disturbed site. Annual turnover of litter varied from 69-73% and the turnover time ranged between 1.37-1.45 years. The turn over time was higher for heavily disturbed site and lower for lightly disturbed site. The heavily disturbed site of all the circle showed the sandy loam soil texture, whereas moderately and lightly disturbed site comprised of sandy loam, sandy clay loam and clay soil texture, respectively. The bulk density decreases from heavily disturbed site to lightly disturbed site and the pH of soils ranged from 5.57-6.89 across the circle. Across the circle the total soil nitrogen ranged from 0.12-0.21%, phosphorus from 10.03-24.00 kg and Potassium from $139.88-448.35kg\;ha^{-1}$, respectively. Our results demonstrate that anthropogenic disturbances regime significantly influences forest floors in terms of mass, composition and dynamics along with litterfall rate and soil properties.

Effect of Superovulatory Regimens on Ovarian Response and Embryo Production in Fine Wool Sheep in Tropics

  • Naqvi, S.M.K.;Gulyani, R.;Pareek, S.R.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.13 no.5
    • /
    • pp.595-599
    • /
    • 2000
  • Fine wool sheep (n=18) maintained in a tropical environment were allocated to three treatment groups. Estrus was induced with two injections of $PGF_{2{\alpha}}$ (10 mg. im) at 10 days interval. Superovulation treatment started 2 days prior to the second injection of $PGF_{2{\alpha}}$. Each ewe was treated with a total dose of 25 units FSH (Super-OV) i.m. every 12 hover 3 days; Group 2 were also injected i.m. with 200 IU PMSG at the first injection of FSH; Group 3 was treated as in Group 2 and also with GnRH ($4{\mu}g$ Buserelin) at the onset of estrus. The ewes in estrus were mated with a fertile ram. Ovarian examination and recovery of embryo and ova were performed at laparoscopy and laparotomy on day 3 or 4 after mating. Data for onset of estrus, duration of estrus, number of corpora lutea (CL), number of unnovulated large follicle (LF), embryo recovery rate, embryo quality and fertilization recorded for the 3 groups. Ewes in the Group 1 set in estrus later (p<0.05; $50.0{\pm}7.29h$) than the ewes in Group 2 ($24.5{\pm}3.58$) and 3 ($32.5{\pm}3.58h$). The duration of estrus, ovarian size and ovarian response (number of CL and LF) did not differ significantly (p>0.05) among the 3 groups. The proportion of ewes with a superovulatory response (${\geq}2$ CL) was the lowest (50%) in Group 1 treated with FSH alone but ova/embryo recovery (100%) and fertilization (100%) was significantly (p<0.05) higher than Group 2 (58.3 and 85.7%, respectively) and Group 3 (48.6 and 50%, respectively). It is concluded that in tropical fine wool sheep, there is no difference in the 3 treatments for yield of good quality embryos but ovarian response and ovulation rate increased on additional use of PMSG and GnRH respectively to FSH alone.

Study of the Relationship between the East Asian Marginal SST and the Two Different Types of El Niño (서로 다른 두 유형의 엘니뇨와 동아시아 인근 해역 표층 온도 상관성 연구)

  • Yoon, Jin-Hee;Yeh, Sang-Wook
    • Ocean and Polar Research
    • /
    • v.31 no.1
    • /
    • pp.51-61
    • /
    • 2009
  • In this study we define the two different types of El $Ni{\tilde{n}}o$, i.e., the eastern Pacific El $Ni{\tilde{n}}o$ (i.e., EP-El $Ni{\tilde{n}}o$) versus the central Pacific El $Ni{\tilde{n}}o$ (i.e., CP-El $Ni{\tilde{n}}o$), during the boreal summer (June-July-August, JJA) and winter (December-January-February, DJF) using the two NINO indices in the tropical Pacific. The two different types of El $Ni{\tilde{n}}o$ significantly differ in terms of the location of the maximum anomalous sea surface temperature (SST) in the tropical Pacific. The CP-El $Ni{\tilde{n}}o$ has been observed more frequently during recent decades compared to the EP-El $Ni{\tilde{n}}o$. In addition, our analysis indicates that the statistics of CP-El $Ni{\tilde{n}}o$ during JJA is closely associated with the warming trend in the central equatorial Pacific. We also examine the different responses of the East Asian marginal SST to the two types of El $Ni{\tilde{n}}o$ during JJA and DJF. The CP-El $Ni{\tilde{n}}o$ during both JJA and DJF is concurrent with warm SST anomalies around the Korean Peninsula including the East China Sea, which is in contrast to the EP-El $Ni{\tilde{n}}o$. Such different responses are associated with the difference in tropics/mid-latitude teleconnections via atmosphere between the two types of El $Ni{\tilde{n}}o$. Furthermore, our results indicate that atmospheric diabatic forcing in relation to the precipitation variability is different in the tropical Pacific between the EP-El $Ni{\tilde{n}}o$ and the CP-El $Ni{\tilde{n}}o$.

Towards Conservation of Omani Local Chicken: Phenotypic Characteristics, Management Practices and Performance Traits

  • Al-Qamashoui, B.;Mahgoub, O.;Kadim, I.;Schlecht, E.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.27 no.6
    • /
    • pp.767-777
    • /
    • 2014
  • Characterizing local chicken types and their mostly rural production systems is prerequisite for designing and implementing development and conservation programs. This study evaluated the management practices of small-scale chicken keepers and the phenotypic and production traits of their chickens in Oman, where conservation programs for local livestock breeds have currently started. Free-range scavenging was the dominant production system, and logistic regression analysis showed that socio-economic factors such as training in poultry keeping, household income, income from farming and gender of chicken owners influenced feeding, housing, and health care practices (p<0.05). A large variation in plumage and shank colors, comb types and other phenotypic traits within and between Omani chicken populations were observed. Male and female body weight differed (p<0.05), being $1.3{\pm}0.65$ kg and $1.1{\pm}0.86$ kg respectively. Flock size averaged $22{\pm}7.7$ birds per household with 4.8 hens per cock. Clutch size was $12.3{\pm}2.85$ and annual production $64.5{\pm}2.85$ eggs per hen. Egg hatchability averaged $88{\pm}6.0%$ and annual chicken mortality across all age and sex categories was $16{\pm}1.4%$. The strong involvement of women in chicken keeping makes them key stakeholders in future development and conservation programs, but the latter should be preceded by a comprehensive study of the genetic diversity of the Omani chicken populations.

Phenotypic diversity, major genes and production potential of local chickens and guinea fowl in Tamale, northern Ghana

  • Brown, Michael Mensah;Alenyorege, Benjamin;Teye, Gabriel Ayum;Roessler, Regina
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.30 no.10
    • /
    • pp.1372-1381
    • /
    • 2017
  • Objective: Our study provides information on phenotypes of local chickens and guinea fowl and their body measures as well as on major genes in local chickens in northern Ghana. Methods: Qualitative and morphometric traits were recorded on 788 local chickens and 394 guinea fowl in urban households in Tamale, Ghana. Results: The results showed considerable variation of color traits and numerous major genes in local chickens, while color variations and related genotypes in guinea fowl were limited. In local chickens, white was preferred for plumage, whereas dark colors were preferred for beak and shanks. More than half of the chickens carried at least one major gene, but the contributions of single gene carriers were low. All calculated allele frequencies were significantly lower than their expected Mendelian allele frequencies. We observed higher mean body weight and larger linear body measures in male as compared to female chickens. In female chickens, we detected a small effect of major genes on body weight and chest circumference. In addition, we found some association between feather type and plumage color. In guinea fowl, seven distinct plumage colors were observed, of which pearl grey pied and pearl grey were the most prevalent. Male pearl grey pied guinea fowl were inferior to pearl grey and white guinea fowl in terms of body weight, body length and chest circumference; their shank length was lower than that of pearl grey fowl. Conclusion: Considerable variation in qualitative traits of local chickens may be indicative of genetic diversity within local chicken populations, but major genes were rare. In contrast, phenotypic and genetic diversity in local guinea fowl is limited. Broader genetic diversity studies and evaluation of trait preferences of local poultry producers are required for the design of appropriate breeding programs.

Begomoviruses and Their Emerging Threats in South Korea: A Review

  • Khan, Mohammad Sajid;Ji, Sang-He;Chun, Se-Chul
    • The Plant Pathology Journal
    • /
    • v.28 no.2
    • /
    • pp.123-136
    • /
    • 2012
  • Diseases caused by begomoviruses (family Geminiviridae, genus Begomovirus) constitute a serious constraint to tropical and sub-tropical agro-ecosystems worldwide. In recent years, they have also introduced in temperate regions of the world where they have great impact and are posing a serious threat to a variety of greenhouse crops. Begomoviral diseases can in extreme cases reduce yields to zero leading to catastrophic losses in agriculture. They are still evolving and pose a serious threat to sustainable agriculture across the world, particularly in tropics and sub-tropics. Till recently, there have been no records on the occurrence of begomoviral disease in South Korea, however, the etiology of other plant viral diseases are known since last century. The first begomovirus infected sample was collected from sweet potato plant in 2003 and since then there has been gradual increase in the begomoviral epidemics specially in tomato and sweet potato crops. So far, 48 begomovirus sequences originating from various plant species have been submitted in public sequence data base from different parts of the country. The rapid emergence of begomoviral epidemics might be with some of the factors like evolution of new variants of the viruses, appearance of efficient vectors, changing cropping systems, introduction of susceptible plant varieties, increase in global trade in agricultural products, intercontinental transportation networks, and changes in global climatic conditions. Another concern might be the emergence of a begomovirus complex and satellite DNA molecules. Thorough understanding of the pathosystems is needed for the designing of effective managements. Efforts should also be made towards the integration of the resistant genes for the development of transgenic plants specially tomato and sweet potato as they have been found to be widely infected in South Korea. There should be efficient surveillance for emergence or incursions of other begomoviruses and biotypes of whitefly. This review discusses the general characteristics of begomoviruses, transmission by their vector B. tabaci with an especial emphasis on the occurrence and distribution of begomoviruses in South Korea, and control measures that must be addressed in order to develop more sustainable management strategies.

Assessment of Stratospheric Prediction Skill of the GloSea5 Hindcast Experiment (GloSea5 모형의 성층권 예측성 검증)

  • Jung, Myungil;Son, Seok-Woo;Lim, Yuna;Song, Kanghyun;Won, DukJin;Kang, Hyun-Suk
    • Atmosphere
    • /
    • v.26 no.1
    • /
    • pp.203-214
    • /
    • 2016
  • This study explores the 6-month lead prediction skill of stratospheric temperature and circulations in the Global Seasonal forecasting model version 5 (GloSea5) hindcast experiment over the period of 1996~2009. Both the tropical and extratropical circulations are considered by analyzing the Quasi-Biennial Oscillation (QBO) and Northern Hemisphere Polar Vortex (NHPV). Their prediction skills are quantitatively evaluated by computing the Anomaly Correlation Coefficient (ACC) and Mean Squared Skill Score (MSSS), and compared with those of El Nino-Southern Oscillation (ENSO) and Arctic Oscillation (AO). Stratospheric temperature is generally better predicted than tropospheric temperature. Such improved prediction skill, however, rapidly disappears in a month, and a reliable prediction skill is observed only in the tropics, indicating a higher prediction skill in the tropics than in the extratropics. Consistent with this finding, QBO is well predicted more than 6 months in advance. Its prediction skill is significant in all seasons although a relatively low prediction skill appears in the spring when QBO phase transition often takes place. This seasonality is qualitatively similar to the spring barrier of ENSO prediction skill. In contrast, NHPV exhibits no prediction skill beyond one month as in AO prediction skill. In terms of MSSS, both QBO and NHPV are better predicted than their counterparts in the troposphere, i.e., ENSO and AO, indicating that the GloSea5 has a higher prediction skill in the stratosphere than in the troposphere.

Economical Sweating Function in Africans: Quantitative Sudomotor Axon Reflex Test

  • Lee, Jeong-Beom;Bae, Jun-Sang;Choi, Jeong-Hwan;Ham, Joo-Hyun;Min, Young-Ki;Yang, Hun-Mo;Kazuhiro, Shimizu;Matsumoto, Takaaki
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.8 no.1
    • /
    • pp.21-25
    • /
    • 2004
  • People in tropics have the ability to tolerate heat by residential permanence in the tropics. Previously, we have shown that African and Thai subjects who lived for whole their lives in only their respective countries sweat less under hot conditions than South Koreans who also lived whole their lives in Korea. The difference in sweating responses was attributed to the dissimilar central and peripheral sweating mechanisms operating in people from both groups. In the present study, acetylcholine (ACh), the primary transmitter for the sudomotor functions, was iontophoretically administered to South Koreans and Africans to determine the characteristic sudorific responses of their acclimatized biologic make-up to their respective environments. Using quantitative sudomotor axon reflex test (QSART), direct (DIR) and axon reflex (AXR) responses were evaluated. The findings revealed that the sweat onset-time among South Koreans was 0.91 min earlier than among Africans (P<0.01). The axon reflex sweat volume of nicotine receptor activity AXR(1) and sweat volume of muscarinic receptor activity DIR(2) among South Koreans were 79% and 53% greater (P<0.01), respectively. These results indicate that the reduced thermal sweating among Africans is at least in part attributed to the diminished sensitivity of sweat glands to ACh.