Reproduction rate and viability of Merino,Nilagiri and halfbred Merino. II. Age specific replacement rate and net reproduction rate     

M. Mohan  V. Ulaganathan  I. M. Rodricks  C. K. Bhuvanakumar  M. Iyue 《Tropical animal health and production》1986,18(3):177-183

Summary Age specific replacement rate, net reproduction rate and intrinsic rate of population increase were estimated from records over a period of 11 years of Merino, Nilagiri and halfbreds. On an average for every 1000 ewes mated 830 ewes lambed, 917 lambs were born, 898 lambs were weaned and 422 ewe lambs survived to joining age (one and a half years) in Nilagiri sheep. The corresponding figures were 665, 685, 590 and 228 in Merino and 664, 709, 691 and 341 in halfbreds. Nilagiri ewes in intermediate ages had more multiple births and older ewes weaned more lambs. The flock strength was not maintained unless the ewes were kept till the fifth lambing in Merino, third lambing in Nilagiri and fourth lambing in halfbred Merino. These results along with the culling levels indicated that the low reproductive efficiency in halfbreds may not be critical enough to avoid introduction of Merino for improvement in productivity. However, the poor reproductive efficiency of the Merino in this country may necessitate repeat importations of Merino rams for production of halfbreds.

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Resumen Se estimó la tasa específica de edad de reemplazo, la tasa neta de reproducción y la tasa intrínsica de incremènto poblacional, a partir de registros tomados a través de II a?os, de ovejas de las razas Merino, Nilagiri y Merino media sangre. En promedio, por cada 1000 ovejas apareadas, 830 parieron, 917 corderos nacieron, 898 corderos se destetaron y 422 alcanzaron la edad de apareamiento (1 1/2 a?os), en ovejas Nilagiri. Los promedios correspondientes en Merino, fueron 665, 685, 590 y 228, y en Merino media sangre 664, 709, 691 y 341. Las ovejas Nilagiri en edad intermedia, tuvieron más mellizos y las ovejas más viejas, destetaron más corderos. La vitalidad del reba?o no se pudo mantener, a memos que las ovejas se dejaran hasta el quinto parto en Merino, tercero en Nilagiri y cuarto parto en media sangre. Estos resultados junto con los niveles de descarte, indicaron, que la baja eficiencia reproductiva de las media sangre, posiblemente no es suficientemente crítica, para evitar la introducción de sangre Merino, tendiente al mejoramiento de la productividad. Sin embargo, la pobre eficiencia reproductiva de la raza Merino observada en el país, solo podría superarse mediante la importación contínua de machos, para la producción de media sangre.

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Résumé Le taux de renouvellement, le taux net de reproduction et le taux intrinsèque d’augmentation de la population ont été enregistrés pendant une période de onze ans pour les races Mérinos, Nilagiri et demi-sang. En moyenne, on a eu 917 agneaux nés pour 1000 brebis accouplées/830 brebis agnelantes; 898 agneaux ont été sevrés et 422 jeunes brebis ont survécu jusqu’à l’age de la lutte (un an et demi) dans la race Nilagiri. Pour les Mérinos, les chiffres correspondant sont: 665, 685, 590 et 228, et pour les demi-sang: 664, 709, 691 et 341. Les brebis Nilagiri d’age intermédiaire ont eu plus de naissances multiples et les plus vielles brebis donnent naissance à plus d’agneaux. Pour que l’effectif du troupeau se maintienne, les brebis doivent être conservées jusqu’au cinquième agnelage chez les Mérinos, au troisième chez les Nilagiri et au quatrième chez les croisés Mérinos. Ces résultats, ainsi que les niveaux de réforme, indiquent que le bas rendement en reproduction des demi-sang n’est pas suffisamment crucial pour éviter l’introduction de Mérinos dans le but d’augmenter la productivité. Toutefois les maigres performances de reproduction du Mérinos dans le pays obligent à des importations répétées de béliers Mérinos pour la production des demi-sang.

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Characterization of CO₂ Responsiveness in a Brassica oxycamp Interspecific Hybrid     

D. C. Uprety  Neeta Dwivedi  Rajat Mohan 《Journal of Agronomy and Crop Science》1998,180(1):7-13

A study of the characterization of CO₂ responsiveness in Brassica oxycamp and its parents Brassica oxyrrhina and Brassica campestris was done using open top chamber technology. The response of the X. B. oxycamp (hybrid) to elevated CO₂ was significantly positive in respect of photosynthesis and growth and similar to that of its parent B. campestris. X B. oxycamp and B. campestris with greater sink potential responded significantly, whereas B. oxyrrhina with a poor sink, did not respond to CO₂ enrichment. Photosynthetic changes at elevated CO₃ levels in the hybrid and parents are partially attributed to the CO₂ effects on stomatal conductance and chlorophyll fluorescence.  相似文献   

Prevalence of anaplasmosis in ruminants in Northern India     

R N Mohan  R C Pathak 《The Indian veterinary journal》1966,43(8):685-689

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A model of lamb production from an autumn catch crop     

P.A. Geisler  J.E. Newton  R.D. Sheldrick  A.E. Mohan 《Agricultural Systems》1979,4(1):49-57

A model of lambs feeding on an autumn catch crop is described. The program must be supplied with data on the crop of interest, and with utilisation factors for that crop. The program then computes figures on land use and gross margins for management policies chosen by the user.When supplied with available data on catch crops, calculations indicate that under certain circumstances use of such a crop to fatten lambs in the autumn may well be a profitable venture. Thus it is concluded that more data on such crops should be collected.  相似文献   

Effect of vertical mulch on moisture conservation and yield of sorghum in Vertisols     

M.S.Rama Mohan Rao  V.Ranga Rao  M Ramachandram  R.C Agnihotri 《Agricultural Water Management》1977,1(4):333-342

The intake rate of the local Vertisol is very low (0.08 cm/h). Vertical mulch was used from 1971 to 1976 in order to improve infiltration. Higher moisture contents were recorded near the mulch. The favourable effects of mulch extended to 1.5 m on either side of the mulch row. Vertical mulching exerted a greater influence on crop yields under dry conditions than in normal and above normal seasons. Compared with low yields in control plots (grain: 0.2 q/ha (20 kg/ha); straw: 9.5 q/ha (950 kg/ha)) mulches spaced at 2, 4 and 8 m produced 3.9 q/ha of grain and 19.0 q/ha of straw under the extremely dry conditions of 1972–1973. However, the increase in grain and straw yields under wet conditions in 1973–1974 was only 47.2 and 15.0%, respectively. Averaged over dry and wet years, vertical mulching resulted in 45.1 and 37.9% higher grain and straw yields. The favourable effects of vertical mulching were found to last for 4 years. Considering dry and wet years, a spacing of 4 m was found to be ideal. Placing sorghum stubble as a vertical mulch to the top of the salt zone (30 cm) was found to be as good as placing it to a depth of 90 cm.  相似文献   

Serologic survey of slaughter-age ostriches (Struthio camelus) for antibodies to selected avian pathogens     

Ley EC  Morishita TY  Harr BS  Mohan R  Brisker T 《Avian diseases》2000,44(4):989-992

Serum samples from 163 slaughter-age ostriches (Struthio camelus) in Ohio and Indiana were tested for antibodies to avian influenza virus (AIV), Newcastle disease virus (NDV), paramyxovirus (PMV) 2, PMV3, PMV7, infectious bursal disease virus (IBDV), Bordetella avium, Mycoplasma synoviae, Mycoplasma gallisepticum, Ornithobacterium rhinotracheale, Salmonella pullorum, Salmonella gallinarum, and Salmonella typhimurium. One ostrich had antibodies to AIV H5N9, 57% of the ostriches had antibodies to NDV, four ostriches had antibodies to both NDV and PMV2, and one ostrich had antibodies to NDV, PMV2, PMV3, and PMV7. None of the ostriches had antibodies to IBDV, B. avium, M. synoviae, M. gallisepticum, O. rhinotracheale, S. pullorum, S. gallinarum, and S. typhimurium. This is the first report of antibodies to avian influenza and PMV7 in ostriches in the United States.  相似文献   

Counting India's wild tigers reliably     

Karanth KU  Gopalaswamy AM  Kumar NS  Delampady M  Nichols JD  Seidensticker J  Noon BR  Pimm SL 《Science (New York, N.Y.)》2011,332(6031):791

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Decay of the GRB 990123 optical afterglow: implications for the fireball model     

Castro-Tirado AJ  Zapatero-Osorio MR  Caon N  Cairos LM  Hjorth J  Pedersen H  Andersen MI  Gorosabel J  Bartolini C  Guarnieri A  Piccioni A  Frontera F  Masetti N  Palazzi E  Pian E  Greiner J  Hudec R  Sagar R  Pandey AK  Mohan V  Yadav RK  Nilakshi  Bjornsson G  Jakobsson P  Burud I  et al 《Science (New York, N.Y.)》1999,283(5410):2069-2073

Broad-band (ultraviolet to near-infrared) observations of the intense gamma ray burst GRB 990123 started approximately 8.5 hours after the event and continued until 18 February 1999. When combined with other data, in particular from the Robotic Telescope and Transient Source Experiment (ROTSE) and the Hubble Space Telescope (HST), evidence emerges for a smoothly declining light curve, suggesting some color dependence that could be related to a cooling break passing the ultraviolet-optical band at about 1 day after the high-energy event. The steeper decline rate seen after 1.5 to 2 days may be evidence for a collimated jet pointing toward the observer.  相似文献   

生防制剂与呋喃丹颗粒剂防治根结线虫幼虫的效果   总被引：2，自引：0，他引：2  

N.VijayaKumari  P.Sjathamma 《浙江农业学报》2002,14(3):159-162

印度南方根结线虫广泛地分布于印度南部灌桑园，特别是轻质土壤的桑园，它严重地影响桑叶的产量和质量，人们曾采用农业和化学等防治措施进行桑园线虫的防治，但效果并不理想，为此，考虑用生物防治方法来进行试验研究，本研究采用拟青霉和轮枝孢真菌两种生防制剂及化学杀线虫剂呋喃丹颗粒剂对线虫幼虫进行致死性试验。每种生物制剂滤液设置3个浓度，分别为100％，75％，和50％，结果发现，该两种真菌制剂在滤液浓100％下72h后的杀虫率分别为73．55％和78．45％，两者无显著差异。虽然它们对幼虫的致死效果比化学杀线虫剂呋喃丹效果略微差些，但生物剂对自然环境，人畜安全，因此，生物制肯望成为更经济，更安全的杀线虫剂。  相似文献   

Improved HPLC method for the determination of curcumin,demethoxycurcumin, and bisdemethoxycurcumin   总被引：5，自引：0，他引：5  

Jayaprakasha GK  Jagan Mohan Rao L  Sakariah KK 《Journal of agricultural and food chemistry》2002,50(13):3668-3672

Commercially available curcumin, a bright orange-yellow color pigment of turmeric, consists of a mixture of three curcuminoids, namely, curcumin, demethoxycurcumin, and bisdemethoxycurcumin. These were isolated by column chromatography and identified by spectroscopic studies. The purity of the curcuminoids was analyzed by an improved HPLC method. HPLC separation was performed on a C(18) column using three solvents, methanol, 2% AcOH, and acetonitrile, with detection at 425 nm. Four different commercially available varieties of turmeric, namely, Salem, Erode, Balasore, and local market samples, were analyzed to detect the percentage of these three curcuminoids. The percentages of curcumin, demethoxycurcumin, and bisdemethoxycurcumin as estimated using their calibration curves were found to be 1.06 +/- 0.061 to 5.65 +/- 0.040, 0.83 +/- 0.047 to 3.36 +/- 0.040, and 0.42 +/- 0.036 to 2.16 +/- 0.06, respectively, in four different samples. The total percentages of curcuminoids are 2.34 +/- 0.171 to 9.18 +/- 0.232%.  相似文献