Investigating the genetic architecture of conception and non-return rates in Holstein cattle under heat stress conditions
- 27 Downloads
This study aimed to investigate the genetic variability of conception rate (CR) and non-return rate (NR) in Iranian dairy cows under heat stress conditions. A total of 34,304 records of CR, and NR at 45 days (NR45) and 90 days (NR90) after the first insemination, from 21,405 Holstein cows were included in this study. The weather records were obtained from seven meteorological stations located at a distance of less than 70 km from the farms. Temperature-Humidity Index (THI) was determined for each record on the insemination day. The statistical models for CR, NR45, and NR90 included the fixed effects of herd-year-season, parity, milk yield, and THI. Genetic components were estimated using an animal model and fitting random regression models on THI based on the Bayesian method. Results showed similar decreasing trends for CR, NR45, and NR90 when increasing the THI levels. The additive genetic variance of heat tolerance for CR, NR45, and NR90 were 0.008 ± 0.0004, 0.0262 ± 0.007, and 0.0254 ± 0.006, respectively. The additive genetic variance of heat tolerance increased directly with THI, and therefore, our findings indicate that a combined selection using heat tolerance can be considered for genetic evaluation of reproduction traits under heat stress conditions.
KeywordsConception rate Non-return rate Genetic variation Environmental stress Heat tolerance
The authors would like to thank the Industrial Agriculture Company of Vahdat, the general directorate of the meteorology, and veterinary organizations for providing the reproductive and meteorological data.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
Animal welfare and use committee approval was not needed for this study as datasets were obtained from pre-existing databases.
- Abramowitz, M. and Stegun, I.A., 1965. Handbook of Mathematical Functions. Dover, New York.Google Scholar
- Alphonsus, C., Akpa, G.N., Barje, P.P., Nwagu, B.I. and Orunmuyi, M., 2014. Evaluation of fertility traits of Friesian X Bunaji dairy cows, Animal Research International, 11, 1851--1862Google Scholar
- Buffington, D.E., Collazo-Aruchu, A., Canton, H.H., Pritt, D., Thatcher, W. and Collier, R.J., 1981. Black globe-humidity index (BGHI) as comfort equations for cows, Transactions of the American Society of Agricultural Engineers, 7, 329Google Scholar
- Carabaño, M.J., Ramón, M., Díaz, C., Molina, A., Pérez-Guzmán, M.D. and Serradilla, J.M., 2017. BREEDING AND GENETICS SYMPOSIUM: Breeding for resilience to heat stress effects in dairy ruminants. A comprehensive review, Journal of Animal Science, 95(4), 1813--1826Google Scholar
- Collier, R.J. and Zimbelman, R.B., 2007. Heat stress effects on cattle: what we know and what we don’t know. 22nd Annual Southwest Nutrition and Management Conference Proceedings. Tempe, AZ, 76-83.Google Scholar
- Hansen, P.J., 2007. Effects of environment on bovine reproduction, in: Youngquist, R.S. (Eds.), Current Therapy in Large Animal. Theriogenology, Philadelphia: WB Saunders, pp. 431-441.Google Scholar
- Hansen, P.J., 2013. Cellular and molecular basis of therapies to ameliorate effects of heat stress on embryonic development in cattle, Animal Reproduction, 10, 322--333Google Scholar
- Kirkpatrick, M., Lofsvold, D. and Bulmer, M., 1990. Analysis of inheritance, selection and evolution of growth trajectories, Genetics, 124, 979--993Google Scholar
- Madsen, P. and Jensen, J., 2007. A user’s guide to DMU. University of Aarhus, DJF, Research Centre Foulum, Denmark.Google Scholar
- Misztal, I., Aguilar, I., Tsuruta, S., Sanchez, J.P. and Zumbach, B., 2010. Studies on heat stress in dairy cattle and pigs. In Proceedings of the 9th World Congress on Genetics Applied to Livestock Production, ID625., German Society of Animal Science: Leipzig, Germany.Google Scholar
- Nguyen, T.T.T., Bowman, P. J., Haile-Mariam, M., Pryce,J. E., Hayes, B. J., 2016. Genomic selection for tolerance to heat stress in Australian dairy cattle. Journal of Dairy Science, 99, 2849--2862Google Scholar
- SAS Institute Inc. 2003. SAS 9.1.3. Help and documentation, Cary, NC: SAS Institute IncGoogle Scholar
- Sigdel, A., Vaca, J.A., Aguilar, I., Abdollahi-Arpanahi, R. and Peñagaricano F., 2018. Genetic analysis of heat tolerance for conception rate in US Holstein cows, Annual Meeting Integrating Dairy Science Globally, Knoxville, Tennessee.Google Scholar
- Stewart, B.M., Block, J., Morelli, P., Navarette, A.E., Amstalden, M., Bonilla, L., Hansen, P.J. and Bilby, T.R., 2011. Efficacy of embryo transfer in lactating dairy cows during summer using fresh or vitrified embryos produced in-vitro with sex-sorted semen, Journal of Dairy Science, 94, 3437--3445CrossRefGoogle Scholar