Dose time of breeding affect the incidence of early cmbryonic mortality and reproductive performance in buffalo? [electronic resource].

Includes references.

This work aimed at studying the relationship between time of breeding and early embryonic losses in buffalo. The Effect of this time on some reproductive traits was also studied. For that. 32 clinically normal buffalo cavers were used. All buffalo cows calved normally and no cases of retained placenta were recorded. Heat detection was performed throughout the 24-hours of the day-round using a TV closed circuit unit. Heat detection was started from the 10th day post-partum. A voluntary waiting period of 40 days was allowed to the dams before breeding. Blood samples were collected from the jugular vein at 5-days intervals for the determination of P 4 concentration. An additional blood sample was obtained on the day of estrus to confirm the occurrence of heat. In addition, a vasectomized buffalo bull was used as an aid for heat detection. The buffalo cows were randomly assigned into 4 groups according to the time of breeding. The dams of the comparable groups were bred at 3.0:1:0.4 hrs (G1, n=9); 11.6:1:0.5 hrs (G2. n=8); 16.2:tO.9 hrs (G3, n=7) and 24.7:1:1.1 hrs (G4. n=8) after the beginning of standing heat using a fertile buffalo bull. Rectal palpation was performed on the same days of blood sampling: Pregnancy was diagnosed per-rectum 45-60 days post service. The incidence of early cmbryonic losses was assessed on the basis of both rectal palpation results and P4 concentration (when its level was sustained above 1 ng/ml for 45 days) after a successful service, then _ abrupt decline to ≤0.5 ng did occur. .The Effect of time of breeding on the days-open, number heats to-conception, number of services/conception. conception rate and calving interval was also studied.

Summary in Arabic.

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