Reduced age at first calving: effects on lifetime production, longevity, and profitability
نویسندگان
چکیده
منابع مشابه
Reduced Age at First Calving: Effects on Lifetime Production, Longevity, and Profitability
The time between birth and first calving represents a period in which replacement heifers are not generating income. Instead this rearing period requires considerable capital expenditures including feed, housing, and veterinary expenses. These expenses constitute 15 to 20% of the total expenses related to milk production (Heinrichs, 1993). A basic approach to reducing this cost is to reduce the...
متن کاملLifetime production of beef heifers calving first at two vs three years of age.
Records of Angus, Hereford, Shorthorn, and first-cross cows born from 1960 to 1963 were used to study the effect of age at first calving and culling policy on cumulative survival (SU), number of breeding seasons (BS), pregnancies (PG), calves born (CB) and alive at 72 h (C72) and at weaning (CW), calf weaning weights (WW), and input/output efficiency, up to 12 yr of age. The 155 cows born in 19...
متن کاملEffect of age at first calving on longevity and fertility traits for Holstein cattle
Effects of age at first calving (AFC) on functional longevity of Czech Holstein cows and their reproduction traits in the first lactation were analyzed using the first lactation data of 605 538 Holstein cows first calved from 1993 to 2008. Three classes were formed for AFC: low age class (16–24 months), average age class (25–30 months), and high age class (33–46 months). Effects of AFC on lengt...
متن کاملThe Effect of Age at First Calving and Calving Interval on Productive Life and Lifetime Profit in Korean Holsteins
This study was performed to estimate the effect of age at first calving and first two calving intervals on productive life and life time profit in Korean Holsteins. Reproduction data of Korean Holsteins born from 1998 to 2004 and lactation data from 276,573 cows with birth and last dry date that calved between 2000 and 2010 were used for the analysis. Lifetime profit increased with the days of ...
متن کاملCalving day and age at first calving in Angus heifers.
Because of difficulties in data collection and analysis, in most breeds there have been limited ways to evaluate fertility in females on a between-herd basis. The objective of this study was to determine the heritabilities (direct and maternal) for CD (calving day) and AFC (age at first calving) in American Angus heifers and to evaluate the potential for using these traits in genetic improvemen...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Kansas Agricultural Experiment Station Research Reports
سال: 2004
ISSN: 2378-5977
DOI: 10.4148/2378-5977.3172