Diet Calcium and pH Versus Mineral Balance in Holstein Cows 84 Days Pre- to 2 Days Postpartum
نویسندگان
چکیده
منابع مشابه
Genetic 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 کاملEffect of days postpartum and endogenous reproductive hormones on GNRH-induced LH release in dairy cows.
Forty-eight Holstein and Guernsey cows were assigned according to age and breed to one of seven groups based on days following parturition. Cows in Groups II to VII received an intramuscular injection of 100 ~tg gonadotropin releasing hormone (GnRH) on either 1 or 2, 3 or 4, 5 or 6, 7 or 8, 12 or 13, or 18 or 19 days postpartum, respectively (six cows per group). An injection of the carrier veh...
متن کاملModels for prediction of days to first ovulation based on changes in endocrine and nonendocrine traits during the first two weeks postpartum in Holstein cows.
Regression models were developed for prediction of days to first postpartum ovulation in Holstein cows milked twice daily. Variables subjected to least squares multiple regression analysis included experimental data collected during weeks 1 and 2 postpartum from 20 cows that ovulated first between 15 and 34 days postpartum. Changes in serum estradiol (AE), number of ovarian follicles ;~ 10 mm d...
متن کاملThe relationships between energy balance, milk production and ovulation in postpartum Holstein cows.
Energy balance and serum progesterone concentrations were monitored during early lactation in a group of high producing Holstein cows. The postpartum interval to normal ovulation averaged 36 +/- 6 days (range 6 to 83 days). Average energy balance during the first 20 days of lactation (cumulative daily calculated energy balance divided by days in milk) was inversely related to days to normal ovu...
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...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 1976
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(76)84355-x