FR 22. Comparison of three methods for the synchronization of oestrus cycles using prostaglandin F2a in dry multiparous cows and heifers

The objetive of this study was to evaluate the synchronization effect of estrous cycles in 3 different protocols in 5 different sites. An analogue of the PGF2a was used (Delprostenate) with a fourth of its commercial dose (200 mg).The number of animals were 34, 38, 38; 18, 19, 18; 31, 32, 28; 34, 32, 40; 15, 9, 22 for the 5 experiments and 3 treatments, respectively. Treatment 1(T1) consisted in one intramuscular (i.m) injection of PGF2a 5 days after being started the artificial insemination (AI) (day 0 = heat) in those animals that did not show heat at the moment.In T.2 and T.2 PGF2a was injected twice with an interval of 11 and 15 days respectively. Analysis 1 started when only (T1) or last injection of PGF2a (T2 and 3) was given and it ended 6 days later. In the last protocols (T2 and 3) AI was started 3 days before the second injection of PGF2a took place (Analysis 2).A model that included treatment, experiment and interaction treatment-experiment was used. The dependant variables were H% (heat rate) and NR% (non-return rate). In conclusion, the results obtained showed that T3 using an analogue of the PGF2a (Delprostenate) with a fourth of it commercial dose (200 mg) was similar or better than the other two protocols except in H% in one of the experiments.

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Bibliographic Details
Main Authors: Rodriguez Blanquet, Juan B., Burgueño, Juan, Mas, Carlos Jaime, Pereyra, Fernando
Format: Digital revista
Language:spa
Published: Asociacion Latinoamericana de Produccion Animal 2005
Online Access:https://ojs.alpa.uy/index.php/ojs_files/article/view/287
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Summary:The objetive of this study was to evaluate the synchronization effect of estrous cycles in 3 different protocols in 5 different sites. An analogue of the PGF2a was used (Delprostenate) with a fourth of its commercial dose (200 mg).The number of animals were 34, 38, 38; 18, 19, 18; 31, 32, 28; 34, 32, 40; 15, 9, 22 for the 5 experiments and 3 treatments, respectively. Treatment 1(T1) consisted in one intramuscular (i.m) injection of PGF2a 5 days after being started the artificial insemination (AI) (day 0 = heat) in those animals that did not show heat at the moment.In T.2 and T.2 PGF2a was injected twice with an interval of 11 and 15 days respectively. Analysis 1 started when only (T1) or last injection of PGF2a (T2 and 3) was given and it ended 6 days later. In the last protocols (T2 and 3) AI was started 3 days before the second injection of PGF2a took place (Analysis 2).A model that included treatment, experiment and interaction treatment-experiment was used. The dependant variables were H% (heat rate) and NR% (non-return rate). In conclusion, the results obtained showed that T3 using an analogue of the PGF2a (Delprostenate) with a fourth of it commercial dose (200 mg) was similar or better than the other two protocols except in H% in one of the experiments.