Sheep - AgRIS
Sheep - AgRIS Sheep - AgRIS
ix) Frequency of collection Honmode and Tiwari (1971) have observed a significant reduction in semen, volume in successive semen collection period of 50, 80 and 110 days in Malpura and Chokla breed. Sperm concentration decreased with increase in frequency of semen collection. 7.2.2.6 Ram Semen Dilution The egg yolk diluent developed by Lardy and Philips (1939) is found satisfactory for ram semen. For this purpose equal volumes of fresh egg yolk and sterilised phosphate buffer (0.2 g dihydrogen potassium phosphate and 2.0 g disodium hydrogen phosphate per 100 ml of pyrogen free triple distilled water) are mixed thoroughly. The pH of the mixture is close to 6.75. If is is not, it should be adjusted by the addition of sterile M/15 citrate buffer or bicarbonate can be used to replace the phosphate buffer without effect on the glycolysis (Moore, 1949). The replacement of the citrate buffer with glycine has improved the survival time of ram semen (Ahmed, 1955, Roy et al., 1956 and Skolosvkaya et al., 1956). Milk appears to be the most useful dilutor for ram semen (Istvan, 1956; Foilmom et al.,1956; Macpherson,1957 and Hill et al., l 958). Miller (1975) reported the use of diluents like egg yolk citrate, heated milk from ewes, cow skim milk and accessory secretions from vasectomised rams. Of the above diluents, cow milk or skim milk heated at 92°V gpt 10 minutes was found to give good results with dilution rate of 1:4. Sahni (1967) recommended that at least 50 million spermatozoa per dose are necessary for conception in case the diluted semen is deposited in the cervix. 7.2.2.7 Preservation of Semen Successful storage with optimum fertility of ram semen is a world wide problem. Researches have been carried out to evolve a suitable dilutor for ram semen in this country, but the results obtained are not very encouraging. The glycine egg yolk dilutor has been found to improve the spermatozoal survial of ram semen as compared to egg yolk citrate (E.Y.C.), later Roy et al., (1962) observed successful storage of ram semen for a longer period in glycine yolk diluent in the 1:10 to 1:20 semen dilutions. Although ram semen can be stored for few days but it is desirable to use fresh semen because fertility is reduced rapidly with storage. Immediately after collection, the semen is diluted with extenders like fresh cow milk boiled and cooled for utilizing the semen within 4 hours of its collection. Similarly freshly prepared egg yolk citrate glucose (EYCG) can be used for diluting semen for immediate use or any time upto 24 hours. EYCG contains 0.8g glucose and 20% egg yolk in 2.879% solution of sodium citrate. A new diluter named Egg yolk Mcillvaine glucose (EYMG) evolved at CSWRI gives better preservation and fertility results. It contains 20 ml egg yolk, 0.8 g glucose, 300 mg streptopenicillin and 100 ml McIllvaine buffer. An ejaculate of 1 ml containing 3-4 billion spermatozoa, diluted 1: and inseminated with 0.1 ml dose, permits 25 ewes to be inseminated in the cervix with approximately 120 million sperms in each dose. For fertilization 0.05 to 0.2 ml of fresh semen with a minimum of 120 to 125 million spermatozoa is effective. In stored chilled semen the dose should be doubled. The results of insemination with semen stored for 24 hours are around 10 per cent lower than with the use of freshly diluted semen. However, doubling the dose reduces the difference in conception rate. Large amount of semen is likely to overflow into the vagina and go waste. The ewes in heat should be detected both in the morning and evening. Those detected in the evening should be inseminated next morning and those detected inthe morning should be inseminated the same evening. With the realization of a limited scope to use diluted semen for large scale artificial insemination programmes in sheep, there is a need to develop a viable technology for cryopreservation of ram semen. There is enough potential for wedespread use of frozen semen as it can be collected and stored Sahni (1967) in his detailed studies on the storage problem of indigenous ram semen has reported a quite satisfactory survival in heated cow milk and has recommended that cow milk appears to be a dilutor of considerable merit in the preservation of ram semen and also observed it to be sigruficantly superior to buffalo, goat and skim milk. The milk and yolk 407
containing diluents enriched with additives did not show results better than milk diluent alone and Cornell University Externder. Keeping quality of ram semen in these diluents showed significant seasonal variations but generally superior values of motility could still be observed in spring, rainy and autumn season. Effect of higher dilutions (1: 10 to 1 :100) in these diluents upto 72 h of storage interval showed that there has been deterioration in keeping quality of ram semen with the increase of dilution rates beyond 1:10 and effect was more pronounced in egg yolk citrate as compared to glycine yolk and Cornell University Extender diluents on storage at 5-7°C upto 72 h. However, Tiwari, et al. (1968) observed better survival upto 30 h in dilution rates varing from 1:3 to 1:10 depending upon the room temperature in different seasons it could be possible to utilise diluted semen within 34 h after collection and dilution for artificial insemiantion and glucose saline without egg yolk may be used for dilution of semen to be utilised quickly within 2 h of storage at 30°C. Ram semen preservation studies (Sahni and Tiwari, 1972), were further carried out, on efficacy of the dilution rates, storage temperature, additives, semen container storage media, cooling rates etc. Results revealed higher spermatozoal survival in egg yolk citrate glucose diluent (EYCG) as compared to EYC, heated cow milk, milk + egg yolk at 8, 24, 48,72 h of storage interval. Irrespective of storage media, (refrigerator, semen shipper) and the diluents higher spermatozoal survial have been observed in glass screw capped vials. Out of all the diluents testes, EYCG gave higher satisfactory results at different storage interval which was mainly due to better buffering capacity of the diluent. Further studies were then confined to the EYCG diluents only. Significant differences were observed in percent spermatozoal survival and pH duet to variation in nurnber of live and normal spermatozoa (25-400xl0 6 ) in 0.1 ml of diluted semen. However, such differences were non-significant upto 24h of storage intervals and irrespective of number of live sperrnatozoa per inseminating dose (0.1 ml) about 70-80 per cent sperm motility have been observed upto 24 h of storage interval. This shows that concentrated ram semen could be stored successfully upto 24 h and could be utilized for breeding operations. Indigenous rams did not differ among themselves in relation to spermatozoal survival. However, difference between breeds was found to be significant. Indigenous and halfbred rams showed relatively higher sperm survival than exotic rams at each storage. interval. Differences between Rambouillet and Soviet Merino were nonsignificant. Addition of 1,3 and 5 per cent gelatine and polyvenyle alcohol in EYCG diluent did not provide significant beneficial effect on spermatozoal survival and pH during storage. In other studies carried out by Singh and Saxena (1965) and Saxena and Singh (1967) it has been observed that motility and percent live sperrnatozoa was highest in skim milk yolk followed by egg yolk glucose bicarbonate diluent than EYC and CUE upto 168 h of storage at 3°C. However, during storage there was no automorphological changes in sperrnatozoa as reported earlier in EYC diluent upto 72 h of storage, (Joshi and Singh, 1968a,b,c) in a comparative study on the efficacy of the diluents have reported higher sperm survival in yolk containing diluents enriched with fructose, tomato juice and glycine, skim milk diluent containing yolk, glucose or fructose. Beneficial effect of caproic acid on sperm motility during storage has been observed by Honmode (1972). Sahni and Roy (1972c) studied the effect of deep freezing (79°C) on post thawing revival of sheep and goat sper natozoa using various levels of glycerol, different equilibration time and rate of freezing in EYC and cow milk diluent. The post thawing survival varied from 10-14 percent in different trials and considerable variation between rams with respect to freezability was noted. The efficiency of EYCG was further compared with diluents prepared from some known buffers by Tiwari et al. (1978). Out of many, the percent motility and live spermatozoa was relatively better in diluents prepared form the Mcillvain and Tris buffer containing yolk and glucose similar to that of EYCG. Over the above in better survival, the most common characteristics in these diluents were the absence of sperm clustering (Sperm agglutination) which was about 20-30 percent in EYCG at 24 h of storage and also relatively better buffering capacity. This shows that these diluents might be able to give better fertility as compared to EYCG diluent. Factors affecting long term preservation are: 408
- Page 21 and 22: 4.2 Distribution of type breeds in
- Page 23 and 24: Table 4.1 continued...... Region/Br
- Page 25 and 26: Table 4.2 continued....... SI. Bree
- Page 27 and 28: 5. Genetics 5.1 Chromosome Profile
- Page 29 and 30: esponsible for the formation of one
- Page 31 and 32: the exercise these animals did not
- Page 33 and 34: For understanding the inheritance o
- Page 35 and 36: with a dense growth of relatively l
- Page 37 and 38: produced on rations which contain i
- Page 39 and 40: The Coefficient of Variation The co
- Page 41 and 42: 5.6.3 Wool Production/Wool yield an
- Page 43 and 44: 6. Breeding 6.1 Components of Sheep
- Page 45 and 46: elationships. Certain coat colors a
- Page 47 and 48: Selection on this basis means that
- Page 49 and 50: ii) Independent Culling Method In t
- Page 51 and 52: eflected by increase in average fle
- Page 53 and 54: at 75 or 8-4 monthly intervals comp
- Page 55 and 56: Based on the crossbreeding results,
- Page 57 and 58: Table 6.8 Means and standard errors
- Page 59 and 60: month post-weaning individual feedl
- Page 61 and 62: ams) in November, 1975 for evaluati
- Page 63 and 64: een heavily fed and therefore may h
- Page 65 and 66: need for one or more "teasers" to d
- Page 67 and 68: ii) Consistency The normal consiste
- Page 69 and 70: collection frequencies per day in 3
- Page 71: iv) Altitude High altitude and poor
- Page 75 and 76: 6. Nutrients Although spermatozoa u
- Page 77 and 78: 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
ix) Frequency of collection<br />
Honmode and Tiwari (1971) have observed a significant reduction in semen, volume in<br />
successive semen collection period of 50, 80 and 110 days in Malpura and Chokla breed.<br />
Sperm concentration decreased with increase in frequency of semen collection.<br />
7.2.2.6 Ram Semen Dilution<br />
The egg yolk diluent developed by Lardy and Philips (1939) is found satisfactory for ram<br />
semen. For this purpose equal volumes of fresh egg yolk and sterilised phosphate buffer (0.2 g<br />
dihydrogen potassium phosphate and 2.0 g disodium hydrogen phosphate per 100 ml of<br />
pyrogen free triple distilled water) are mixed thoroughly. The pH of the mixture is close to<br />
6.75. If is is not, it should be adjusted by the addition of sterile M/15 citrate buffer or<br />
bicarbonate can be used to replace the phosphate buffer without effect on the glycolysis<br />
(Moore, 1949). The replacement of the citrate buffer with glycine has improved the survival<br />
time of ram semen (Ahmed, 1955, Roy et al., 1956 and Skolosvkaya et al., 1956).<br />
Milk appears to be the most useful dilutor for ram semen (Istvan, 1956; Foilmom et<br />
al.,1956; Macpherson,1957 and Hill et al., l 958). Miller (1975) reported the use of diluents like<br />
egg yolk citrate, heated milk from ewes, cow skim milk and accessory secretions from<br />
vasectomised rams. Of the above diluents, cow milk or skim milk heated at 92°V gpt 10<br />
minutes was found to give good results with dilution rate of 1:4.<br />
Sahni (1967) recommended that at least 50 million spermatozoa per dose are necessary for<br />
conception in case the diluted semen is deposited in the cervix.<br />
7.2.2.7 Preservation of Semen<br />
Successful storage with optimum fertility of ram semen is a world wide problem.<br />
Researches have been carried out to evolve a suitable dilutor for ram semen in this country, but<br />
the results obtained are not very encouraging. The glycine egg yolk dilutor has been found to<br />
improve the spermatozoal survial of ram semen as compared to egg yolk citrate (E.Y.C.), later<br />
Roy et al., (1962) observed successful storage of ram semen for a longer period in glycine yolk<br />
diluent in the 1:10 to 1:20 semen dilutions.<br />
Although ram semen can be stored for few days but it is desirable to use fresh semen<br />
because fertility is reduced rapidly with storage. Immediately after collection, the semen is<br />
diluted with extenders like fresh cow milk boiled and cooled for utilizing the semen within 4<br />
hours of its collection. Similarly freshly prepared egg yolk citrate glucose (EYCG) can be used<br />
for diluting semen for immediate use or any time upto 24 hours. EYCG contains 0.8g glucose<br />
and 20% egg yolk in 2.879% solution of sodium citrate. A new diluter named Egg yolk<br />
Mcillvaine glucose (EYMG) evolved at CSWRI gives better preservation and fertility results. It<br />
contains 20 ml egg yolk, 0.8 g glucose, 300 mg streptopenicillin and 100 ml McIllvaine buffer.<br />
An ejaculate of 1 ml containing 3-4 billion spermatozoa, diluted 1: and inseminated with 0.1 ml<br />
dose, permits 25 ewes to be inseminated in the cervix with approximately 120 million sperms<br />
in each dose. For fertilization 0.05 to 0.2 ml of fresh semen with a minimum of 120 to 125<br />
million spermatozoa is effective. In stored chilled semen the dose should be doubled. The<br />
results of insemination with semen stored for 24 hours are around 10 per cent lower than with<br />
the use of freshly diluted semen. However, doubling the dose reduces the difference in<br />
conception rate. Large amount of semen is likely to overflow into the vagina and go waste. The<br />
ewes in heat should be detected both in the morning and evening. Those detected in the evening<br />
should be inseminated next morning and those detected inthe morning should be inseminated<br />
the same evening.<br />
With the realization of a limited scope to use diluted semen for large scale artificial<br />
insemination programmes in sheep, there is a need to develop a viable technology for<br />
cryopreservation of ram semen. There is enough potential for wedespread use of frozen semen<br />
as it can be collected and stored<br />
Sahni (1967) in his detailed studies on the storage problem of indigenous ram semen has<br />
reported a quite satisfactory survival in heated cow milk and has recommended that cow milk<br />
appears to be a dilutor of considerable merit in the preservation of ram semen and also<br />
observed it to be sigruficantly superior to buffalo, goat and skim milk. The milk and yolk<br />
407
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