Relationships Between Age and Body Weight at Calving and Production in First Lactation Ayrshires and Holsteins
نویسندگان
چکیده
منابع مشابه
An analysis of age and body weight at first calving for Holsteins in the United States.
In a national survey of US dairy producers, only 2.7 +/- 0.5% of Holstein dairy operations reported achieving recommended target ranges of age < or = 24 months and body weight (BW) > or = 550 kg at first calving. Allowing for wider target ranges, still only 14.6 +/- 1.3% of Holstein dairy operations reported achieving age < or = 25 months and BW > or = 544.3 kg at first calving. Ages of individ...
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چکیده هدف اصلی تحقیق حاضر مطالعه و بررسی رابطه بین خودکارامدی شنیداری با درک شنیداری بود.همچنین رابطه درک شنیداری وخودکارآمدی شنیداری با جنسیت و رابطه خودکارامدی شنیداری با سن نیز مورد بررسی قرار گرفت.تعداد شصت زبان اموز-سی دختر و سی پسر- کانون زبان ایران در مرکز خرم آباد به صورت تصادفی انتخاب شدند. روشهای به کار رفته در جمع اوری داده ها عبارت بودند ازبرسشنامه خودکارآمدی و تست درک شنیداری لانگ...
15 صفحه اولThe Application of Recursive Mixed Models for Estimating Genetic and Phenotypic Relationships between Calving Difficulty and Lactation Curve Traits in Iranian Holsteins: A Comparison with Standard Mixed Models
In the present study, records on 22872 first-parity Holsteins collected from 131 herds by the Animal Breeding and Improvement Center of Iran from 1995 to 2014 were considered to estimate genetic and phenotypic relationships between calving difficulty (CD) and the lactation curve traits, including initial milk yield (Ap), ascending (Bp) and descending (Cp) slope of the lactation curves, peak mil...
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In this paper the genetic relationships between major reproductive traits in beef cattle (Calving Date, Calving Interval and Age at First Calving) and type traits have been estimated to evaluate the usefulness of type classification in predicting reproductive performance in beef cattle. We estimated favourable genetic correlations between Calving Interval and type traits ranging from 2 0.027 to...
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 ...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 1991
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(91)78170-8