Effect of inseminating cows in estrus following a presynchronization protocol on reproductive and lactation performances
نویسندگان
چکیده
منابع مشابه
Effect of temperature-humidity index on productive and reproductive performances of Iranian Holstein cows
Calving records from April 1996 to December 2005 comprising 31863 calving events of 1173 dairy cows in a large commercial dairy herd were used to evaluate the effects of heat stress, using temperature-humidity index (THI) on milk yield and composition and reproductive performance of Holstein dairy cows under humid climatic conditions of Rasht in Iran. THI values were grouped into six groups: 30...
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Objectives were to compare the effect of presynchronization and resynchronization methods on fertility responses of grazing dairy cows at first and second artificial insemination (AI) and pregnancy rate during the entire breeding season. Lactating dairy cows (n = 1,263) in 2 seasonal grazing farms were blocked, within farm, by parity, breed and days in milk. Within each block, cows were randoml...
متن کاملOvarian function and estrus in dairy cows during early lactation.
The onset of ovarian function and occurrence of estms were monitored in two groups of Holstein cows over the first 90 days postpartum. Group 1 consisted of 36 animals housed in a free stall area and observed continuously for estrus with closed circuit television and a time lapse videorecorder. Group 2 consisted of 33 cows housed in tie stalls with estrus detected by the herdsmen. Blood samples ...
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The aim of this study was to investigate the effect of milking frequency (three times daily vs. two times daily) on the lactation curve shape, partial and 305-d lactation performance in Holstein dairy cows in Iran. Data from February 2000 to December 2012 comprising 217345 lactations on 141364 cows distributed in 324 herds collected by the Animal Breeding Center of Iran were used. The mean milk...
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نتایج این مطالعه نشان می دهد که مقدار کلسیم (یونیزه و تام)، منیزیم و فسفر به طور معنی داری تغییر پیدا کرد به جزء مقدار کلسیم تام و منیزیم در روش داخل عضلانی که تغییر معنی داری نداشته است. بر اساس نتایج این مطالعه می توان نتیجه گیری کرد که اکسی تتراساکلین بر روی مقادیر سرمی کلسیم و منیزیم تأثیر می گذارد باید مقدار این کاتیون ها در بیماران، در هنگامی که اکسی تتراسایکلین استفاده می شود مورد توجه ق...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 2010
ISSN: 0022-0302
DOI: 10.3168/jds.2010-3179