Genetic Parameters and Trends of Milk, Fat, Days Open, and Body Weight After Calving in North Carolina Experimental Herds
نویسندگان
چکیده
منابع مشابه
Estimation 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 کاملGenetic Relationship between Milk Production, Calving Ease and Days Open at First Parity in Holstein Cows
Data containing 14,188 lactation and reproductive records of Korean Holstein cows at first parity distributed across 3,734 herd-year-season groups were analyzed to get genetic (co)variance estimates for milk yield, fat yield, calving ease, and days open. Milk and Fat yields were adjusted to 305 d. Heritabilities and genetic correlations were estimated in two different animal models on which wer...
متن کاملgenetic evaluation of age at first calving, open days and milk production of holstein cattle in iran
the objective of this study was to estimate genetic parameters coupled with genetic and phonotypic trends for age at first calving (afc), open days(od) and milk yield(my) of first lactation in iranian holstein cows. records of reproduction and production for genetic evaluation from 1984 to 2005 for afc, od and my were 71736, 20126 and 20126, respectively. single and two-variable animal models w...
متن کاملeffect of bataine and sulphate supplement on wool and milk characteristics and lambs performance in naine ewes
تعداد 20 رأس میش نژاد نائینی 6+-24 ماهه، با میانگین وزن 2/3-+40 کیلوگرم، همراه با 20 رأس بره های آنها در قالب طرح کاملا تصادفی اثر بتائین و مکمل سولفات بر خصوصیات شیر و پشم و عملکرد بره ها بررسی شد. میش ها بطور تصادفی در چهار تیمار قرار گرفتند. تیمارها عبارت بودند از: 1-گروه شاهد 2-بتائین (05/0 درصد ماده خشک) 3-سولفات (24/0 سولفور درصد ماده خشک 4-بتائین هرماه با سولفات. جیره غذائی طبق nrc با مح...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 2000
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(00)75004-1