Impact of calving interval on milk yield and longevity of primiparous Estonian Holstein cows
نویسندگان
چکیده
منابع مشابه
Genetic Trends for Milk Yield, Persistency of Milk Yield,Somatic Cell Count and Calving Interval in Holstein Dairy Cows of Iran
The objective of the present study was to estimate genetic trends for lactation milk yield, persistency of milk yield, somatic cell count and interval between first and second calving in Holstein dairy cows of Iran. The dataset consisted of 210,625 test day and 25,883 first parity cows with milk yield recorded from July 2002 to September 2007 comprising 97 herds in Iran. Breeding values of anim...
متن کاملMilk yield of primiparous beef cows from three calving systems and varied weaning ages.
Primiparous beef cows produced in 3 calving systems were used in a 2-yr study with a completely random design to measure milk yield throughout a 190-d lactation (2002, n = 20; 2003, n = 24 per calving system). Calving occurred in late winter (average calving date = February 4 +/- 2 d), early spring (average calving date = March 30 +/- 2 d), and late spring (average calving date = May 26 +/- 1 d...
متن کاملeffect of seed priming and irrigation regimes on yield,yield components and quality of safflowers cultivars
این مطالعه در سال 1386-87 در آزمایشگاه و مزرعه پژوهشی دانشگاه صنعتی اصفهان به منظور تعیین مناسب ترین تیمار بذری و ارزیابی اثر پرایمینگ بر روی سه رقم گلرنگ تحت سه رژیم آبیاری انجام گرفت. برخی از مطالعات اثرات سودمند پرایمینگ بذر را بر روی گیاهان مختلف بررسی کرده اند اما در حال حاضر اطلاعات کمی در مورد خصوصیات مربوط به جوانه زنی، مراحل نموی، عملکرد و خصوصیات کمی و کیفی بذور تیمار شده ژنوتیپ های م...
Heterogeneous Within-Herd Variance. 2. Genetic Relationships Between Milk Yield and Calving Interval in Grade Holstein Cows
Genetic and phenotypic (co)variances for mature equivalent yield of 4% FCM and calving interval were simultaneously estimated by REML for grade Holstein cows in first and second parity. Data were 305d mature equivalent lactation records and calving dates for 299,441 daughters of 2489 AI sires first calving from 1970 to 1985 in California, New York, or Texas. Data were divided into three time pe...
متن کاملGenetic (Co)variance between Age from First to Third Calving and Milk Yield of Holstein Cows in the Tropics
A total of 245187 records of the first three lactations of 131126 Holstein cows in tropical conditions were used to estimate the genetic (co)variance components between age at calving and its respective milk productions. A multivariate analysis of six traits was performed. Heritability for age at calving (h2AC) and milk yield (h2MY) decrease from the ...
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ژورنال
عنوان ژورنال: Czech Journal of Animal Science
سال: 2020
ISSN: 1212-1819,1805-9309
DOI: 10.17221/130/2020-cjas