نتایج جستجو برای: interval between calving to first insemination

تعداد نتایج: 11258826  

A. Mirzaei A. Omidi, Kh. Nowroozi M. Mohebbi-Fani S. Nazifi

Background: It was hypothesized that under apparently good management practices in dairy farms, some cows may not be metabolically perfect during the breeding period and this may affect their performance. Aims: This study was conducted to assess probable metabolic drawbacks in mid-lactation dairy cows affecting their performance. Methods: Thirt...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده زبانهای خارجی 1390

the purpose of the present study was to see which one of the two instruction-processing instruction (pi) and meaningful output based instruction (mobi) accompanied with prompt and recast- is more effective on efl learners’ writing accuracy. in order to homogenize the participants in term of language proficiency a preliminary english test (pet) was administrated between 74 intermediate students ...

A. Akhlaghi A. R. Abdolmohammadi H. Atashi, M. B. Sayyadnejad M. Dadpasand M. J. Zamiri

This study was carried out to investigate the relationship between early lactation curve parameters andcalving interval in Holstein cows of Iran. In order to describe the lactation curve, the incomplete gammafunction was fitted to 5,754,428 test-day milk records corresponding to 766,108 lactations on 315,634 cowsin 2,448 herds. Cows with higher milk yield during early lactation had shorter calv...

2012
V. Zink J. Lassen M. Štípková

The aim of this study was to estimate genetic parameters for female fertility and production traits in first-parity Czech Holstein cows and to quantify the effect of using this information on the accuracy of a selection index in seven different scenarios. In order to estimate genetic (co)variance components, the DMU software running an AI-REML algorithm was used. The analyses were made using a ...

Journal: :Animal reproduction science 2000
Y T Gröhn P J Rajala-Schultz

The objectives of this presentation are to review results of our previous and on-going research with respect to the risk factors and consequences of poor reproductive performance in dairy cows, and to develop an economic framework to optimize decisions related to dairy cow reproductive performance. To make profitable breeding and replacement decisions, the farmer must account for factors includ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه مازندران - دانشکده علوم انسانی 1390

iv abstract this study examined the linguistic behaviors of two iranian efl teachers each of them teaching learners of two similar proficiency levels, a beginner level and an intermediate level, to investigate the relationship between the learners proficiency levels and the amounts and purposes for l1 use by the two teachers. the study was carried out to investigate whether there were differe...

Journal: :علوم دامی ایران 0
سجاد طغیانی عبدالاحد شادپرور محمد مرادی شهر بابک محمد دادپسند

to estimate the genetic parameters for production and reproduction traits in holstein cows, information from 15 herds recorded by animal breeding center of iran during 1980 – 2004, were employed. estimations were made using restricted maximum likelihood method under an animal model ranging df-reml and matvec software. estimates of heritabilities for yield traits were moderate and ranged from 0....

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه بیرجند 1389

there has been a gradual shift of focus from the study of rule systems, which have increasingly been regarded as impoverished, … to the study of systems of principles, which appear to occupy a much more central position in determining the character and variety of possible human languages. there is a set of absolute universals, notions and principles existing in ug which do not vary from one ...

Journal: :Journal of dairy science 2006
E Hare H D Norman J R Wright

Trends since 1980 for calving age and calving interval, 2 factors that influence herd life, were examined by parity for 5 breeds of US dairy cattle. Calving data were from cows with records that passed edits for USDA genetic evaluations and were in herds that remained on Dairy Herd Improvement test. First-calf heifers calved at progressively younger ages over time, but the age decline was less ...

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