Impact of management factors on days to conception in dairy heifers
Article Sidebar
Main Article Content
Abstract
Increasing the number of pregnant heifers per time unit improves reproductive efficiency in dairy herds. The objective of this work was to analyze the effect of management factors on conception. Reproductive events of 2532 heifers throughout 37 years were analyzed adjusting proportional risk models. Days to conception (DC) were measured as the interval in days from the start of the service period (IPS) to conception. The observation period per animal was 90 days. Models adjusted for DC include effects of age at IPS, year, number and season of services, conception rate of bulls, and year-to-season interaction with services. The Weibull model adjusts the DC variation pattern. Conception was lower in heifers under 18 months, in the 2nd and 3rd service, and when bulls with less conception rate were used. Conception was higher in fall services by 1.17 times compared to spring services. Identifying management factors affecting days to conception in heifers allows developing strategies to improve reproductive efficiency in dairy herds.
Article Details
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
How to Cite
References
Andreo, N. (2000). Recría de vaquillonas. En XIX Curso Internacional de Producción Lechera. (pp.1-14). Rafaela, Santa Fe, Argentina: INTA Rafaela.
Ansari-Lari, M. y Abbasi, S. (2008). Study of reproductive performance and related factors in four dairy herds in Fars province (southern Iran) by Cox proportional-hazard model. Preventive Veterinary Medicine, 85 (3–4), 158–165. https://doi.org/10.1016/j.prevetmed.2008.02.004
Berry, D. P., Wall, E. y Pryce, J. E. (2014). Genetics and genomics of reproductive performance in dairy and beef cattle. Animal, 8 (Supplements s1), 105–121. https://doi.org/10.1017/S1751731114000743
Brickell, J. S. y Wathes, D. C. (2011). A descriptive study of the survival of Holstein-Friesian heifers through to third calving on English dairy farms. Journal of Dairy Science, 94 (4), 1831–1838. https://doi.org/10.3168/jds.2010-3710
Byerley, D. J., Staigmiller, R. B., Berardinelli, J. G. y Short, R. E. (1987). Pregnancy Rates of Beef Heifers Bred Either on Puberal or Third Estrus. Journal of Animal Science, 65(3), 645–650. https://doi.org/10.2527/jas1987.653645x
Cox, D. R. (1972). Regression Models and Life-Tables. Journal of the Royal Statistical Society. Series B (Methodological), 34 (2), 187–220.
Dairy Australia (2017). InCalf book for dairy farmers (2nd edition). Recuperado de https://www.dairyaustralia.com.au/farm/animal-management/fertility
Ducrocq, V. (1987). An analysis of length of productive life in dairy cattle. Tesis doctoral no publicada. Universidad de Cornell, Ithaca, Nueva York, Estados Unidos.
Ducrocq, V. (2001). Survival Analysis Applied to Animal Breeding and Epidemiology. Manuscrito no publicado, Estación de Genética Cuantitativa y Aplicada, Instituto Nacional de la Investigación Agronómica, Jouy en Josas, Francia.
Ducrocq, V., Sölkner, J. y Mészaros, G. (Agosto 2010). Survival Kit v6 – a software package for survival analysis. EnDocumento presentado en el 9thno. World Congress on Genetics Applied to Livestock Production, Leipzig, Alemania: International Committee for the World Congress on Genetics Applied to Livestock Production.
González-Recio, O., Chang, Y. M., Gianola, D. y Weigel, K. A. (2005). Number of inseminations to conception in holstein cows using censored records and time-dependent covariates. Journal of Dairy Science, 88 (10), 3655–3662. https://doi.org/10.3168/jds.S0022-0302(05)73051-4
González-Recio, O., Perez Cabal, M. A. y Alenda, R.. (2004). Economic value of Female Fertility and its Relationship with profit in Spanish dairy catte. Journal of Dairy Science, 87 (9), 3053–3061. https://doi.org/10.3168/jds.S0022-0302(04)73438-4
Harman, J. L., Casella, G. y Gröhn, Y. T. (1996). The application of event-time regression techniques to the study of dairy cow interval-to-conception. Preventive Veterinary Medicine, 26 (3–4), 263–274. https://doi.org/10.1016/0167-5877(95)00553-6
Hayes, C. J., McAloon, C. G., Carty, C. I., Ryan, E. G., Mee, J. F. y O’Grady, L. (2019). The effect of growth rate on reproductive outcomes in replacement dairy heifers in seasonally calving, pasture-based systems. Journal of Dairy Science, 102(6), 5599–5611. https://doi.org/10.3168/jds.2018-16079
Kalbfleisch, J. D. y Prentice, R. L. (2002). The statistical analysis of failure time data (2ª ed.). New Jersey, Canadá: John Wiley & Sons.
Kaplan, E. L. y Meier, P. (1958). Nonparametric estimation from incomplete observations. Journal of the American Statistical Association, 53 (282), 457-481. https://doi.org/10.1080/01621459.1958.10501452
Le Cozler, Y., Lollivier, V., Lacasse, P. y Disenhaus, C. (2008). Rearing strategy and optimizing first-calving targets in dairy heifers: a review. Animal, 2(9), 1393–1404. https://doi.org/10.1017/S1751731108002498
LeBlanc, S. J. (2010). Assessing the association of the level of milk production with reproductive performance in dairy cattle. The Journal of Reproduction and Development, 56 (Supplement S), S1–S7. https://doi.org/10.1262/jrd.1056S01
Macmillan, K., Loree, K., Mapletoft, R. J. y Colazo, M. G. (2017). Short communication: Optimization of a timed artificial insemination program for reproductive management of heifers in Canadian dairy herds. Journal of Dairy Science, 100(5), 4134–4138. https://doi.org/10.3168/jds.2016-12318
Malchiodi, F., Cecchinato, A. y Bittante, G. (2014). Fertility traits of purebred Holsteins and 2- and 3-breed crossbred heifers and cows obtained from Swedish Red, Montbéliarde, and Brown Swiss sires. Journal of Dairy Science, 97 (12), 7916–7926. https://doi.org/10.3168/jds.2014-8156
McDougall, S., Heuer, C., Morton, J. y Brownlie, T. (2014). Use of herd management programmes to improve the reproductive performance of dairy cattle. Animal, 8 (Supplement 1), 199–210. https://doi.org/10.1017/S1751731114000457
Miglior, F., Muir, B. L., y Van Doormaal, B. J. (2005). Selection Indices in Holstein Cattle of Various Countries. Journal Dairy Science, 88 (3), 1255–1263. https://doi.org/10.3168/jds.S0022-0302(05)72792-2
Miglior, F., Fleming, A., Malchiodi, F., Brito, L. F., Martin, P. y Baes, C. F. (2017). A 100-Year Review: Identification and genetic selection of economically important traits in dairy cattle. Journal of Dairy Science, 100 (12), 10251-10271. https://doi.org/10.3168/jds.2017-12968
Piccardi, M., Balzarini, M., Capitaine Funes, A. y Bo, G. A. (2011). Estrategia informático-analítica para generar indicadores de eficiencia reproductiva en tambos. Documento presentado en las 40o Jornadas Argentinas de Informática - 3er Congreso Argentino de Agroinformática. Córdoba, Córdoba, Argentina.
Piccardi, M., Capitaine Funes, A., Balzarini, M. y Bo, G. A. (2013). Some factors affecting the number of days open in Argentinean dairy herds. Theriogenology, 79(5), 760–765. https://doi.org/10.1016/j.theriogenology.2012.11.032
Pryce, J., Woolaston, R., Berry, D. P., Wall, E., Winters, M., Butler, R. y Shaffer, M. (2014). World Trends in Dairy Cow Fertility. Documento presentado eEn el 10th World Congress on Genetics Applied to Livestock Production (pp. 154). Vancouver, Canada: International Committee for the World Congress on Genetics Applied to Livestock Production.
Shalloo, L., Cromie, A. y McHugh, N. (2014). Effect of fertility on the economics of pasture-based dairy systems. Animal, 8 (Supplement s1), 222–231. https://doi.org/10.1017/S1751731114000615