الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Total of 1167 normal first lactation records of Egyptian buffaloes sired by 98 bulls kept at Mehalet Mousa Farm, belonging to Animal Production Research Institute (APRI), Ministry of Agriculture, Cairo, Egypt during the period from (2002 to 2015) were used to estimate phenotypic and genetic parameters for Total milk yield (TMY), lactation period (LP) and age at first calving (AFC). In addition, four selection indexes were constructed by using two different relative economic values (one phenotypic standard deviation and Lemont method). The records without pedigree, breeding dates and cows affected by diseases and aborted cows were excluded. Two mixed models were used , model 1, was used to analysis milk yield and lactation period, the model includes, the fixed effects of month and year of calving, age at first calving as a covariate and random effects of sires and random errors. The second model was used to analysis age at first calving the model includes the fixed effects of month and year of birth and random effects of sire and errors. Animals were kept loose under semi- open sheds all the year round. All cows were fed add- libitum on Egyptian clover (Trifolum Alexandrinum) and rice straw from December to May and on Sorghum surd grass and berseem hay from June till November. Buffaloes were natural mating. Assignment of sires to cows was at random. Heifers were first artificially inseminated at 18 months of age and 350 kg weight. Female buffalo were handing milked twice a day at 06.00 a. m and 06.00 p.m. Milk yield was recorded to the nearest 0.2 kg. Buffalo producing more than 10 kg a day and those in the last two months of pregnancy were supplemented with extra concentrate rations.