FR 34. Environmental and fisiological factors effects on empty period – calving interval and lenght of gestation in bufaloes
It was evaluated reproductive records of 82 buffaloes with 3 and more calving, who calved beteween 1994 and 1996 from comercial farm in very dry tropical environment with a temperature of 28.7 °C and precipitation of 782 mm. Calving interval (IP), empty period (PV) and lenght of gestation (DG), were studied under environmental factor, considering the year (Y): 94-95 (A1) and 95-96 (A2). Season (E): January-April (E1), May-August (E2) and September-December (E3). It was also considered the effects of the variable: Sex (X), the birth weigth (P) of the calf and the body condition at calving (CC) on IP, PV and DG. Results showed that (A) and (E) influenced (P<.001) and (P<.01) on (IP) and (PV). The average (IP) as (A1) was 376.40 ± 43.40 days and for (A2) was 385.50 ± 49.85 days. The average (IP) due to the season was: for (E1) 394.73 days ± 43.72 ; for (E2) was 413.00 days (n=1) and for (E3) 366.45 days ± 42.09. The average obtained for the (PV) due to (E) was: 80.73 days ± 37.33 ; 100 days (n=1) and 54.04 days ± 33.31 for (E1), (E2) and (E3) respectively. The (PV) for (A1) was 57.30 days ± 39.04 and for (A2) was 61.35 days ± 32.40. The (CC) affect (P<.001) (IP) and (PV), the female buffaloes with (CC) equal or higher of 3.3 the best reproductive parameter. Mean (DG) was 314.04 days ± 8.30 ; the (DG) for male calf was 315.63 days and for female calf was 314.55 days. The born calf with higher weight were resulted of (DG) more long lightly. It is concluded that factor that affect more (IP) and (PV) was the season, equally the body condition at calving is a factor that have to be considerate at the moment to evaluate reproductive parameters.