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Full-Text Articles in Life Sciences

Bovine Respiratory Disease In Feedlot Cattle: Environmental, Genetic, And Economic Factors, G. D. Snowder, L. Dale Van Vleck, L. V. Cundiff, G. L. Bennett Jul 2006

Bovine Respiratory Disease In Feedlot Cattle: Environmental, Genetic, And Economic Factors, G. D. Snowder, L. Dale Van Vleck, L. V. Cundiff, G. L. Bennett

Department of Animal Science: Faculty Publications

The objective of this study was to characterize genetic, environmental, and economic factors related to the incidence of bovine respiratory disease (BRD) in feedlot calves. Records from 18,112 calves representing 9 breeds (Angus, Braunvieh, Charolais, Gelbvieh, Hereford, Limousin, Pinzgauer, Red Poll, and Simmental) and 3 composite types (MARC I, MARC II, and MARC III) over a 15-yr period (1987 to 2001) were evaluated. Disease incidence was observed and recorded by station veterinary and technical staff. The incidence of BRD varied across years, with the annual observed incidence ranging from 5 to 44%. From 1987 to 1992, the annual average incidence …


Calculation Of Adjustment Factors For Standardizing Lactations To Mature Age And 305-Day And Estimation Of Heritability And Repeatability Of Standardized Milk Yield Of Simmental Cattle Reared On Kazova State Farm, Süleyman Çi̇lek, Mehmet Emi̇n Teki̇n Jan 2006

Calculation Of Adjustment Factors For Standardizing Lactations To Mature Age And 305-Day And Estimation Of Heritability And Repeatability Of Standardized Milk Yield Of Simmental Cattle Reared On Kazova State Farm, Süleyman Çi̇lek, Mehmet Emi̇n Teki̇n

Turkish Journal of Veterinary & Animal Sciences

Adjustment factors of lactation milk yield to mature age and 305-day were calculated and heritability and repeatability of milk yield were estimated for Simmental cows reared on Kazova State Farm. A total of 1549 lactation records of Simmental cows reared on Kazova State Farm between 1992 and 2002 were used. The factors for standardizing incomplete lactations to 305-day were estimated by taking 7 calving age groups into consideration (2, 3, 4, 5, 6-8, 9 and 10 years of age and older). The factors for standardizing to mature equivalent estimated by polynomial regression are between the 24^th and 143^rd month and …