Random Regression Analysis of Calving Interval of Japanese Black Cows
نویسندگان
چکیده
منابع مشابه
Association between the lactation curve shape and calving interval in Holstein dairy cows of Iran
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...
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Variace / covariance components of 227118 first lactaiom test-day milk yield records belonged to 31258 Iranian Holstein cows were estimated using nine random regression models. Afterwards, different measures of persistency based on estimation breeding value were evaluated. Three functions were used to adjust fixed lactation curve: Ali and Schaeffer (AS), quadratic (LE3) and cubic (LE4) order of...
متن کاملEstimation of Genetic and Phonotypic Trends for Age at First Calving, Calving Interval, Days Open and Number of Insemination to Conception for Isfahan Holstein Cows
For the current research the records of 62 farms in Isfahan province were available. To estimate genetic and phonotypic trends of reproductive traits such as age at first calving, calving interval, days open and number of insemination to conception rate the records of 63,866 cows including 167793 reproductive records were employed. Farms were covered by Vahdat industrial Agriculturists and Dair...
متن کاملEstimation of Genetic and Phonotypic Trends for Age at First Calving, Calving Interval, Days Open and Number of Insemination to Conception for Isfahan Holstein Cows
For the current research the records of 62 farms in Isfahan province were available. To estimate genetic and phonotypic trends of reproductive traits such as age at first calving, calving interval, days open and number of insemination to conception rate the records of 63,866 cows including 167793 reproductive records were employed. Farms were covered by Vahdat industrial Agriculturists and Dair...
متن کاملSimple and Constrained Selection Indices with and without Calving Interval Included in Selection Goal Function for Holstein Cows of Iran
Two selection goals of inclusion or exclusion of calving interval (CI) in the selection goal function for Holstein cows in Iran, besides milk yield, milk fat percentage, and milk protein percentage, were studied. Four selection indices were composed of using the information on production traits, CI and / or days from calving to first insemination (DFI). The results of the predicted genetic grow...
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ژورنال
عنوان ژورنال: Animals
سال: 2021
ISSN: 2076-2615
DOI: 10.3390/ani11010202