Reproductive Performance Of Cross-Bred Sudanese Dairy Cows Treated With Pgf2α Or Gnrh During Early Postpartum Period

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Date
2015-04-01
Authors
Elzubeir,Faisal Omer Ahmed
Journal Title
Journal ISSN
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Publisher
University of Khartoum
Abstract
The present study was designed to investigate the effects of PGF2α or GnRH injections during postpartum on uterine involution, length of postpartum period, number of services per conception, days open and calving interval in cross-bred Sudanese dairy cows. Experiment I was designed to investigate the effects of PGF2α on the above mentioned parameters. A total of 35 cross-bred dairy cows were employed to execute the effect of PGF2α on the above mentioned postpartum parameters. The cows were randomly distributed into 3 groups A, B (15 cows each) and C (5 cows). Group A is further grouped into 3 subgroups (5 cows each). The first subgroup was given a single injection of PGF2α (500 μg) i.m on day 7, the second subgroup was given a single injection of PGF2α on day 14 and the third subgroup was given a single injection of PGF2α on day 21 postpartum. Group B was grouped into 3 subgroups (5 cows each). The first subgroup was given a double injections of PGF2α (500 μg) i.m on days 0 and 7, the second subgroup on days 8 and 14 and the third subgroup on days 15 and 21 postpartum. Group C was employed as untreated control. The results of this experiment showed that injections of PGF2α significantly (P < 0.05, P < 0.001, P < 0.01 and P < 0.001 respectively) reduce the time taken for uterine involution, length of postpartum period, days open and calving interval. Moreover, the number of services per conception was improved as compared with control (P < 0.05). Experiment II was designed to study the effects of GnRH on the same parameters of the first experiment. A total of 20 cross-bred dairy cows were used to execute the effects of GnRH on the above mentioned parameters. The cows were randomly divided into 2 groups: A and B, with 15 and 5 cows for each respectively. Group A was further subgrouped into 3 subgroups (5 cows each). The first subgroup was given a single injection of GnRH (200 μg) i.m on day 7, the second and third subgroups were given the same dose of GnRH on day 14 and day 21 respectively. Group B was employed as untreated control. The findings of this experiment explained that the injection of GnRH significantly shortens the time needed for uterine involution, postpartum period, days open and calving interval as compared with control (P < 0.005, p < 0.05, P < 0.001 and P < 0.001 respectively). Moreover, the number of services perconception was improved significantly (P < 0.04). It is concluded that the use of PGF2α or GnRH during the first, second or third week postpartum improves the reproductive efficiency of cross-bred dairy cows. Thus a calf per cow per year can be produced if this regime is employed. However, a single injection of PGF2α as early as 7 days has no effects on the above parameters.
Description
89 Pages
Keywords
Bred;Sudanese Dair;Cows Treated;Postpartum Period;Animals;Body weight;Milk;dairy cattle
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