نتایج جستجو برای: calving year

تعداد نتایج: 596348  

O.R. Madibela, W. Mahabile

Retrospective data from Sebele Dairy Farm were analysed for reproductive performance of Friesian/Holstein cows. Three hundred records from 1989 to 1995 were used. The herd was zero grazed and the data was analysed for age at first calving (AFC), calf birth weights (BW), calving interval (CI), days open (DO), calving rate (CR), reproductive wastage (RW) and calving difficulty (CD); dystocia, aft...

Journal: :iranian journal of applied animal science 2015
o.r. madibela w. mahabile

retrospective data from sebele dairy farm were analysed for reproductive performance of friesian/holstein cows. three hundred records from 1989 to 1995 were used. the herd was zero grazed and the data was analysed for age at first calving (afc), calf birth weights (bw), calving interval (ci), days open (do), calving rate (cr), reproductive wastage (rw) and calving difficulty (cd); dystocia, aft...

Journal: :پژوهش های علوم دامی ایران 0
مهدی نافذ سعید زره داران سعید حسنی رحمت سمیعی

in the present study, to estimate genetic parameters and genetic and phenotypic trends in holstein dairy cows in the north of iran, the records from first lactation of 11398 collected from 1989 to 2006 were used. records were collected from 290 herds. productive traits were 305 day-2x adjusted milk and fat yield and reproductive traits were age at first calving, calving interval and dry days. g...

A. Isik H. Hizli, T. Ayasan

The aim of this study was to evaluated body weights and survival rates at birth, 3 and 6 months of age and to determine effects of calving year, season and sex on those traits in Southern Anatolian Redcalves. The animals were raised in Adana East Mediterranean Agricultural Research Institute's Dogankent location between 2000 and 2007 years. Duncan test statistic for estimating the differences b...

Journal: :Journal of animal science 1996
L A Werth S M Azzam J E Kinder

The objective of this study was to evaluate calving intervals and repeatability of calving intervals of young beef cows when breeding seasons were initiated immediately after calving. Average calving date at 2, 3, and 4 yr of age was recorded, and duration of calving interval between the first and second and second and third parities was compared in 178 crossbred beef cows calving between 1981 ...

Journal: :علوم دامی ایران 0
حمیده کشاورزی دانشجوی دکتری، گروه علوم دامی، دانشکدۀ کشاورزی، دانشگاه صنعتی اصفهان علی صادقی سفیدمزگی استادیار، گروه علوم دامی، دانشکدۀ کشاورزی، دانشگاه صنعتی اصفهان غلامرضا قربانی استاد، گروه علوم دامی، دانشکدۀ کشاورزی، دانشگاه صنعتی اصفهان رسول کوثر استادیار، گروه علوم دامی، دانشکدۀ کشاورزی، دانشگاه صنعتی اصفهان

this study was performed to investigate the incidence of abortion based on different definitions and, the effect of climate and herd size on abortion as well as its phenotypic trend. using calving records collected from 16 dairy herds from years 2004 through 2014. incidence rate and analysis of affecting factors on abortion were done using the freq and genmod procedures of sas software, respect...

A. Chegini A.A. Shadparvar, N. Ghavi Hossein-Zadeh

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...

Journal: :علوم دامی ایران 0
حسین مهربان دکتری ژنتیک و اصلاح نژاد دام، گروه علوم دامی، دانشگاه شهرکرد سید مهدی اسماعیلی فرد دانشجوی دکتری ژنتیک و اصلاح نژاد دام، گروه علوم دامی، دانشگاه علوم کشاورزی و منابع طبیعی ساری مجتبی نجفی دانشجوی دکتری ژنتیک و اصلاح نژاد دام، گروه علوم دامی، علوم کشاورزی و منابع طبیعی ساری بیتا عباسی مشائی دانشجوی دکتری ژنتیک و اصلاح نژاد دام، گروه علوم دامی، علوم کشاورزی و منابع طبیعی ساری ابراهیم اسدی خشوئی دکتری ژنتیک و اصلاح نژاد دام، گروه علوم دامی، دانشگاه شهرکرد

a data file containing 607662 (317608) milk (open days) records belonging 294417 (177838) holstein cows that were calved from 1983 to 2008 was used. the bivariate repeatability model was used for data analyzing so that herd, calving year, calving month, days in milk (only for milk trait) and calving age for each parity, were assumed as fixed effects and additive genetics and permanent environme...

2001
N. A. Janovick J. R. Russell D. R. Strohbehn D. G. Morrical S. K. Barnhart

A year-round grazing system for springand fall-calving cows was developed to compare animal production and performance, hay production and feeding, winter forage composition changes, and summer pasture yield and nutrient composition to that from a conventional, or minimal land system. Systems compared forage from smooth bromegrass-orchardgrass-birdsfoot trefoil pastures for both systems in the ...

2009
R. R. Frahm

than to calf birth weight alone. Percent calving difficulty is the percentage of births requiring assistance from the herdsman. Calving scores of3 or higher were classified as difficult births based on a scoring system ranging from I = no assistance to 5 = caesarian birth or abnormal presentation. Due to the substantially higher incidence of calving difficulty in 1978 over 1979 (11.3 percent vs...

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