Abstract
In order to evaluate the reproductive effect of a rotational breeding system, the pregnancy rate of 69 Zebu cows was assessed, 32 late postpartum (211±93 days postpartum, LP) and 37 early postpartum (averaging 63±8 days after calving, EP). In the LP group, 60% (19/32) were cycling before exposure to the bulls but only 38% (14/37) in the EP group. The two groups were dissimilar from the start (p<0.05). The cows were exposed in a rotational breeding system, with six Brahman bulls with previous sexual experience paired off in three groups (A–B, C–D and E–F). The cows were exposed to each pair of bulls for a period of 3 weeks, with one week in between each period, when the females were without the presence of a male. In the LP group, the pair of bulls A–B obtained a pregnancy rate of 72% (23/32), whereas for bulls C–D the pregnancy rate was 33% (3/9) and for bulls E–F the pregnancy rate was 67% (4/6). In contrast, for the EP cows, bulls A–B obtained a pregnancy rate of 32% (12/37), bulls C–D a pregnancy rate of 67% (12/18) and for bulls E–F a pregnancy rate of 55% (6/11). The percentage pregnancy obtained using the pair of bulls A–B differed (p<0.05) between LP and EP, whereas for bulls C–D and E–F it was similar. The pregnancy rate was different (p<0.05) in the first 3 weeks of mating for the LP group, the highest number of cows becoming pregnant during the first 3 weeks of the study. In contrast, the highest number of pregnancies in EP occurred evenly during the last 6 weeks. This study suggests that the reproductive performance of pairs of bulls in a 9-week rotational programme with the overall pregnancy rate is similar (94% in the LP and 81% in the EP). However, the time taken for the females to become pregnant, and hence the performance of the bulls, is related to the average number of days postpartum for the cows.
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REFERENCES
Alberio, R.H., Schiersmann, G., Carou, N. and Mestre, J., 1987. Effect of a teaser bull on ovarian and behavioural activity of suckling beef cows. Animal Reproduction Science, 14, 263-272
Bastidas, P., Troconiz, J., Verde, O. and Silva, O., 1984. Effect of restricted suckling on pregnancy rates and calf performance in Brahman cows. Theriogenology, 21, 289-294
Bolaños, J.M., Galina, C.S., Estrada, S. and Forsberg, M., 1997. Resumption of postpartum ovarian activity monitored by plasma progesterone in anoestrous Zebu (Bos indicus) cattle following temporary weaning and progestogen treatment. Reproduction in Domestic Animals, 32, 267-271
Bolaños, J.M., Forsberg, M., Kindahl, H. and Rodríguez-Martínez, H., 1998. Biostimulatory effects of estrous cows and bulls on resumption of ovarian activity in postpartum anestrous Zebu (Bos indicus) cows in the humid tropics. Theriogenology, 49, 629-636
Chacón, J., Pérez, E., Muller, E., Soderquist, L. and Rodriguez-Martinez, H., 1999. Breeding soundness evaluation of extensively managed bulls in Costa Rica. Theriogenology, 52, 221-231
Chenoweth, P.J., 1997. Bull libido/serving capacity. Veterinary Clinics of North America, Food Animal Practice, 13, 331-344
Dawson-Saunders, B. and Trapp, G.R., 1997. Bioestadística Médica, 2nd edn. (Manual Moderno México, Mexico City)
Galicia, L., Estrada, K.S., Galina, C.S., Pérez, G.E. and Molina, S.R., 1999. Velocidad de gestación en el ganado Bos inducus en el trópico húmedo de Costa Rica. Ciencias Veterinarias, (Costa Rica), 22, 59-69
Galina, C.S. and Arthur, G.H., 1989. Review of cattle reproduction in the tropics. Part 3. Puerperium. Animal Breeding Abstracts, 57, 899-910
Gifford, D.R., D'Occhio, M.J., Sharpe, P.H., Weatherly, T., Pittar, R.Y. and Reeve, D.V., 1989. Return to cyclic ovarian activity following parturition in mature cows and first-calf beef heifers exposed to bulls. Animal Reproduction Science, 19, 209-216
Gregory, R.M., Mattos, R.C. and Lamprecht, M., 1996. Embryonic mortality in bovine ultrasonography evaluation. Arquivos Facultad Veterinaria Universidade Federal de Rio Grande do Sul, Brazil, 24, 25-29
Gutierrez, C., Galina, C.S. and Rubio, I., 1993. The influence of the social structure of a Zebu herd on the manifestation of signs of oestrus. World Review of Animal Production, 28, 70-84
Hornbuckle, T., Ott, R.S., Ohl, M.W., Zinn, G.M. and Weston, P.G., 1995. Effects of bull exposure on the cyclic activity of beef cows. Theriogenology, 43, 411-418
Kastelic, J.P., Curran, S., Pierson, R.A. and Ginther, O.J., 1988. Ultrasonic evaluation of the bovine conceptus. Theriogenology, 29, 39-54
Lunstra, D.D. and Laster, D.B., 1982. Influence of single-sire and multiple-sire natural mating on pregnancy rate in beef heifers. Theriogenology, 18, 373-382
Molina, R., Bolaños, I., Galina, C.S., Pérez, G. and Estrada, S., 2001. Sexual behaviour of Zebu bulls in the humid tropics of Costa Rica: single versus multiple sire groups. Animal Reproduction Science, 64, 139-148
Molina, R., Galina, C.S., Camacho, J., Maquivar, M., Díaz, G.S., Estrada, S. and Martínez, L., 2002. Effect of alternating bulls as a management tool to improve the reproductive performance of suckled Zebu cows in the humid tropics of Costa Rica. Animal Reproduction Science, 69, 159-173
Molina, R., Galina, C.S., Galicia, L. and Estrada, S., 2003. Evaluación de un empadre rotativo sobre el rendimiento reproductivo de vacas cebuinas en monta natural. Agrociencia 37, 1-10
Price, E.O., 1987. Male sexual behavior. Veterinary Clinics of North America, Food Animal Practice, 3, 405-422
Pullan, N.B., 1978. Condition scoring of White Fulani cattle. Tropical Animal Health and Production, 10, 118-120
Rudder, T.H., Seifert, G.W. and Burrow, H.M., 1985. Enviromental and genotypic effects on fertility in a commercial beef herd in central Queensland. Australian Journal of Experimental Agriculture, 25, 489-496
Rupp, G.P., Ball, L., Shoop, M.C. and Chenoweth, P.J., 1977. Reproductive efficiency of bulls in natural service: effects of male to female ratio and single-vs. multiple-sire breeding groups. Journal of the American Veterinary Medical Association, 171, 639-642
Wright, I.A., Rhind, S.M., Smith, A.J. and Whyte, T.K., 1994. Female—female influences on the duration of the post-partum anoestrous period in beef cows. Animal Production, 59, 49-53
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Molina, R., Galina, C., Maquivar, M. et al. Pregnancy Rate in Zebu Cows with Two Different Postpartum Intervals Exposed to a Two-Bull Rotational System. Vet Res Commun 27, 671–680 (2003). https://doi.org/10.1023/A:1027303926829
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DOI: https://doi.org/10.1023/A:1027303926829