Productive and reproductive behavior of three herd of Cebu cattle of the Magdalena Area

The productive and reproductive behavior of 3 herd of cattle is studied of Cebu cattle located in Savannah of Torres, Giron and Lebrija to the northwest of Santander, with heights of 118 to 160 m.s.n.m, temperatures of 25 to 27 centigrade degrees, relative humidity of 65 to 80 percent and plane topography with waves and acid soil. The exploitation system evolved from the continuous shepherding in native prairies to the rotational with improved prairies and mineral supplementation. The system of it mounts it was continuous and oscillate among 35 cows/bull to the beginning and 25-30 cows/bull at the end. Due to the location and different handling, the 3 herds were analyzed independently. 1, 1843 observations were analyzed to measure the interval between childbirths and 478 for the weight to the birth and the weaning (270 days). An analysis was used by minimum squares with unequal subclasses. The weight to the weaning was adjusted by covariance, due to the dispersion of the age to the weaning. For the natality rate they were processed and they analyzed for high X to the 2 3175 herds. The prevalence of infectious illnesses of the reproduction was studied in 156 blood samples and it was analyzed by the pattern 1 of Cavanzo. The intervals among childbirths for the herds 1, 2 and 3 were: 466 days (C V same 24 percent), 458 days (C V same 29 percent) and 513 days (C V same 31 percent), respectively. When studying the effect of the month of the childbirth on the interval among childbirths, the months of low precipitation (December to March and July) they diminished the interval the bull it also influenced in the duration of the interval among childbirths; in all the herds, the effect of the reproducer increased or it diminished the interval significantly. In the herd 1, the weight average to the birth was of 32 but or less 1.9 kg and the males weighed 3.8 kg more that the females. The weight to the weaning was of 219.4 but or less 16.9 kg (C V similar to 8.0 percent) and it was influenced significantly alone for the year of childbirth and for the reproducer. The distribution of the sex was lightly superior for the females (52 percent) the half rate of natality for the 3 was 78.4 percent. The herd 3 presented the rate low (74.5 percent) and the 2, the high (81.6 percent). Regarding illnesses, the 3 herd were free of brucellosis, with a very low incidence, 22 percent, of bovine viral diarrhea (DVB) and 1 parainfluenza-3 percent (PI-3) and a high prevalence (54 percent) of infectious bovine rinotraqueitis (RBI)