Relationships Between Reproduction Traits, Age and Body Weight at Calving, and Days Dry 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...
متن کاملThe 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...
متن کاملG enetic relationships between calving date, calving interval, age at first calving and type traits in beef cattle
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 کاملRelationship between body condition score and health traits in first-lactation Canadian Holsteins.
The objective of this research was to estimate daily genetic correlations between longitudinal body condition score (BCS) and health traits by using a random regression animal model in first-lactation Holsteins. The use of indicator traits may increase the rate of genetic progress for functional traits relative to direct selection for functional traits. Indicator traits of interest are those th...
متن کاملthe relationship between listening self efficacy, listening comprehension, gende, and age in male and female english learners
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 اولذخیره 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: Journal of Dairy Science
سال: 1990
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(90)78737-1