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Genetic studies on gir cattle

By: Chhina, H S.
Publisher: Karnal NDRI 1975Subject(s): Dairy-Cattle-BreedingDissertation note: Ph.D Thesis Panjab University 1975 Nagarcenkar, R Summary: The data conisting of 2,095 lactation record of 502 Gir cows and 348 daughter dam pairs pread over a period of 33 years from the Kandivali cattle breeding farm of Bombay, Gowrakshak Mandi, Bombay were collected and analyed. The averagee age at firt calving wa observed to be 53.60 +0.42 month with co-efficient of variation of 17.40 per cent. o it is said that genetic variability for age at first calving wa fairly low. Th reason and age effect were not foiund to be significant for the milk production based on pooled data. Average lactation yield was highest in second lactation. This indicated that Gir cow attained maturity after the age of 70 months. First lactation milk yield had a higher etimate of heritability than second and third lactation milk yields, pooled average of firt five lactation yield and life time milk production. The average milk yield was maximum in the econd months record wherea it was minimum in th tenth months record. Heritibility etimate of cumulative partial lactation milk yields were higher and also more consistnt than those of monthly consequtive yields. The traits like lactation length, intercalving period and service period pooled over first five record were significantly affected by order of parity. The season effect was not significant in cae of all these trait. The gestation length during first calving and on pooled data of firest five calvings was not significantly affected by any of the effects studied. Lactation length was moderately heritability whereas all other traits tudied were lowly heritable. It could be deduced that econd, fifth or sixth monthly milk yield records a well as 60 days cumulative partial lactation milk yield record based on 10 daughters per sire could be considered adequate for ire proving with fair degree of accuracy and efficiency.
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Item type Current location Collection Call number Status Date due Barcode
Gratis Books Gratis Books NDRI Karnal
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Reference Available G6018
Thesis/Dissertation Thesis/Dissertation NDRI Karnal
Reference Book Collection
Non-fiction P-142 (Browse shelf) Not for loan 47915

Ph.D Thesis Panjab University 1975 Nagarcenkar, R

The data conisting of 2,095 lactation record of 502 Gir cows and 348 daughter dam pairs pread over a period of 33 years from the Kandivali cattle breeding farm of Bombay, Gowrakshak Mandi, Bombay were collected and analyed. The averagee age at firt calving wa observed to be 53.60 +0.42 month with co-efficient of variation of 17.40 per cent. o it is said that genetic variability for age at first calving wa fairly low. Th reason and age effect were not foiund to be significant for the milk production based on pooled data. Average lactation yield was highest in second lactation. This indicated that Gir cow attained maturity after the age of 70 months. First lactation milk yield had a higher etimate of heritability than second and third lactation milk yields, pooled average of firt five lactation yield and life time milk production. The average milk yield was maximum in the econd months record wherea it was minimum in th tenth months record. Heritibility etimate of cumulative partial lactation milk yields were higher and also more consistnt than those of monthly consequtive yields. The traits like lactation length, intercalving period and service period pooled over first five record were significantly affected by order of parity. The season effect was not significant in cae of all these trait. The gestation length during first calving and on pooled data of firest five calvings was not significantly affected by any of the effects studied. Lactation length was moderately heritability whereas all other traits tudied were lowly heritable. It could be deduced that econd, fifth or sixth monthly milk yield records a well as 60 days cumulative partial lactation milk yield record based on 10 daughters per sire could be considered adequate for ire proving with fair degree of accuracy and efficiency.

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