Lactation Curves of Purebred and Crossbred Dairy Cattle
نویسندگان
چکیده
منابع مشابه
Economic merit of crossbred and purebred US dairy cattle.
Heterosis and breed differences were estimated for milk yield traits, somatic cell score (SCS), and productive life (PL), a measure of longevity. Yield trait data were from 10,442 crossbreds and 140,421 purebreds born since 1990 in 572 herds. Productive life data were from 41,131 crossbred cows and 726,344 purebreds born from 1960 through 1991. The model for test-day yields and SCS included eff...
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Nine measures related to breeding efficiency were used for comparisons among purebred Ayrshires, Brown Swiss, Holsteins, and Jerseys and between purebreds and 32 crossbred groups representing 2-breed, 3-breed, 5/8, and backcrosses by purebred sires and progeny of crossbred sires. There were four herds wi th Holsteins common to all, Brown Swiss and Jerseys in three herds and Ayrshires in one her...
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The proportional hazards model with censoring was used to assess the effects of breeding value, disease, calving, size, and udder and lactation traits on length of herdlife of 3881 heifers in five herds. Data were recorded over 10 yr from three lines: a Holstein line, an Ayrshire-based line, and a crossbred line. Influences on survival were assessed from data collected at birth, 34, 50, and 82 ...
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The major problems for the dairy practices in the tropical country are low milk yield and short lactation period of either pure exotic or crossbred dairy cattle. Many factors affect milk production in dairy cattle in tropical areas including high environmental temperature and humidity, lower genetic potential for milk production in indigenous cattle and inadequate supply of food during the dry ...
متن کاملClinical Management of Babesiosis in Crossbred Dairy Cattle
Four months back calved crossbred dairy cow had history of coffee coloured urine. Blood smear and Blood samples of this cow were collected on the day of acute stage of infection and then 15th day of post treatment for haematological parameters. Based on the clinical pathonomonic symptom (coffee coloured urine) and blood smear examination presence of Babesia bigemina organisms the disease was di...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 1986
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(86)80386-1