Sheep - AgRIS

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for some parts of eastern states which are subtemperate and humnid. About 30.48 million hectares of land with natural vegetation is available for grazing. The predominant annual grasses are Andropogon, Apluda and Aristida species. The major perennial grasses are Dichanthium, Heteropogon, Sehima and Themeda species. The important trees and shrubs are Acacia, Albizia, Bauhinia and Terminalia species. This regionhas about4.96 million sheep representing 10.08 per cent ofthe total population. They produce about 1.87 million kg of wool, i.e. about 4.55 per cent of India's total wool production. Most ofthe wool is of below 36 S quality except in the Tibetan sheep found in Arunachal Pradesh which produces good carpet quality wool. The majority of the wool produced in the region is suitable only for extremely coarse carpets, blankets and kumblies. 465
12. Wool Production and quality 12.1 GreasyfleeceProduction The greasy (unwashed) fleece weight is usually considered as a measure of the wool yield of a sheep. Though the clean fleece yield is decisive form an economic point of view, but phenotypic correlation between the greasy fleece kept under same enviornmetal conditions is too high (around 0.9) thus the former can be considered satisfactory. A genetic correlation of 0.7 between the greasy and scoured is another measure. Fineness is measured as average fibre diameter and recorded usually on a lanameter or a projection microscope. Such measurements are made at constant temperature and humidity since wool is highly hygroscopic and the diameter of the same fibre will change with the change in temperature and humidity. The fineness and the length are the major factors contributing to the maufacturing quality. There is a high correlation between the spinning count (number of spins of 560 yards in length which can be spun from 1 lb. of scoured wool) and fibre fineness. In Indian wools, measure of medullated fibres (as a percent of total fibres by weight of the total fibres) is also an important character. Uniformity in fineness is usually considered interms of coefficient of variation of average fibre diameter. 12.2 Factors affiecting wool production Level of wool production and fleece structure may be affected by various climatic factors and seasonal changes which can influence the shedding and regeneration of follicles, fiber diameter and fiber length growth rate (Bhasin and Desai, 1965). In cold countries sheep is shorn annually. In India it is normally shorn twice a year but in hot states they are shorn thrice a year. Shearing even in warm climate results in change in the microclimate of sheep. Shearing in a warm environment might stimulate wool growth or in cold conditions might bring about a stress response from adrenal cortex. Injections of adrenocorticotrophic hormone (ACIN), cortisone and the application of cortisone ointments depress wool growth. 12.2.1 Non Genetic a) Humidity and Atmospheric temperature It has been found that humidity differences of 25-30 percent and temperature differences of upto 30°C had no effect. On the other hand there is a marked correlation between the rate of wool growth and mean atmospheric temperature amongst maiden Corriedale ewes fed a uniform maintenance diet throughtout the year. b) Seasonal rhythm The seasonal rhythm persists amongst Corridale ewes fed a ration of constant composition at rates which maintained the effective body weights ofthe ewes constant. Marston (1955) found five fold differences in the rate of wool production of fine wool sheep between lush pastures of spring and the poor pasture of winter. The fundamental causes of the seasonal rhythm of wool growth remains obscure. c) Photoperiodicity The ewes produced lesser wool in winter than in summer. Nutrition, pregnancy and lactation can override or magnify the seasonal effect, but it canbe isolated and measured, provided these factors, are adequately controlled. The photoperiodicity rhythm may be one factor and it is probable that the seasonal rhythm in temperature may be another. d) Hormones Speculation of the mechanisms involved here is perhaps unwarranted at this stage though the probable connection between hormone output and temperature and photoperiod rhythms may be mentioned. Atmospheric temperature is known to affect the output of the thyroid. It has been shown that thyroxin administration and deprivation influences wool growth. The thyroid gland has a permissive effect on wool follicle development and wool growth. Thyroidectomy reduces wool growth to about 40-50% of normal. Administration of thyroxine to normal sheep stimulates wool growth. Dry ewes given a single 60-100 mg implant responded by an increase in wool production by 15%. 466
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1. Introduction ANNEXURE - IX-C SHE
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2. Classification, Origin and Domes
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Nadu, Andhra Pradesh and Karnataka,
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different states it is estimated th
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Table 3.3 continued...... Country N
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een possible because of its substan
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(USA). The Rambouillet as purebreds
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ii) Marwari Deriving its name from
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Pradesh and Bihar, Bijapur, Gulbarg
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elatively tall with little hair exc
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4.2 Distribution of type breeds in
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Table 4.1 continued...... Region/Br
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Table 4.2 continued....... SI. Bree
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5. Genetics 5.1 Chromosome Profile
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esponsible for the formation of one
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the exercise these animals did not
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For understanding the inheritance o
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with a dense growth of relatively l
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produced on rations which contain i
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The Coefficient of Variation The co
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5.6.3 Wool Production/Wool yield an
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6. Breeding 6.1 Components of Sheep
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elationships. Certain coat colors a
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Selection on this basis means that
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ii) Independent Culling Method In t
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eflected by increase in average fle
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at 75 or 8-4 monthly intervals comp
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Based on the crossbreeding results,
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Table 6.8 Means and standard errors
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month post-weaning individual feedl
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ams) in November, 1975 for evaluati
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een heavily fed and therefore may h
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need for one or more "teasers" to d
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ii) Consistency The normal consiste
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collection frequencies per day in 3
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iv) Altitude High altitude and poor
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containing diluents enriched with a
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6. Nutrients Although spermatozoa u
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7. 3.1 Puberty Puberty in the femal
Page 79 and 80: Estrogen in large quantities inhibi
Page 81 and 82: The udder becomes firm and enlarged
Page 83 and 84: 7. 3. 8 Interlambing interval It is
Page 85 and 86: 8. Nutrition 8.1 Components of Shee
Page 87 and 88: allied to the various amino acids o
Page 89 and 90: animals. A deficiency of salt is sh
Page 91 and 92: seem to have most significance in s
Page 93 and 94: Table 8.2 Chemical composition of g
Page 95 and 96: Table 8.3 Nutritive value of fodder
Page 97 and 98: Mineral and vitamin Requirement If
Page 99 and 100: Table 8.5 Total digestible nutrient
Page 101 and 102: Table 8.7 continued....... c) Lacta
Page 103 and 104: shirinking due to reclaimation of l
Page 105 and 106: Sorghum-Berseem-Maize Improved vari
Page 107 and 108: 9. Housing and Management 9.1 Syste
Page 109 and 110: ) Shearing, skirtng and primary cla
Page 111 and 112: The availability of pastures which
Page 113 and 114: fodder as green or hay, concentrate
Page 115 and 116: 9.2.2 Lambs Efforts should be made
Page 117 and 118: Mortality in young lambs and other
Page 119 and 120: land and they depend on the forest
Page 121 and 122: age and fed intensively till they a
Page 123 and 124: Overnight teasing and drafting ridd
Page 125 and 126: The secretion of milk takes place d
Page 127 and 128: with coarse and hairy breeds showed
Page 129: 11. Sheep Production System in Diff
Page 133 and 134: crosses with Dorset and Merinos, Pa
Page 135 and 136: 13. Meat Production 13.1 MeatProduc
Page 137 and 138: Table 13.1 Mutton (sheep) productio
Page 139 and 140: 14.4 Utilization of milk Sheep are
Page 141 and 142: one crushing mills and about 360 bo
Page 143 and 144: 16. Sheep Records It is essential t
Page 145 and 146: 17. Diseases and their Control Morb
Page 147 and 148: Atropin sulphate 2.0 mg/kg. body we
Page 149 and 150: contents by neutralization tests wi
Page 151 and 152: prophylactic, foot and mouth vaccin
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Sheep - AgRIS

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