Effects of postpartum energy balance, body condition score, and insemination time on conception rates of Bonsmara cows bred using timed artificial insemination
DOI:
https://doi.org/10.17159/sajas.v55i10.02Keywords:
beef cattle, conception rate, energy balance, extensive systems, timed artificial inseminationAbstract
Fertility management of extensively farmed beef cattle in South Africa is essential to ensure the economic viability of such production systems. However, the success of timed artificial insemination (TAI) programmes varies, affecting cattle farmers' adoption of this reproductive technique. This study investigated the effects of postpartum energy balance (∆M), body condition score (BCS), time of artificial insemination (morning or afternoon), and any interactions on the conception rates of Bonsmara cows (N = 72, second to ninth parity, BCS ≥2.25) in the Limpopo Province of South Africa. The cows were synchronised in the morning or afternoon using the seven-day CO-Synch synchronisation protocol. Cow live weight and BCS were recorded at synchronisation, TAI, and pregnancy determination, and the data were used to calculate the ∆M. Cows that did not conceive from TAI were naturally mated, and the number of cows that did not conceive was recorded. The average conception rate of cows bred by both TAI and natural mating was 76.7 ± 5.60%. The ∆M and time of artificial insemination did not influence the conception rate. The BCS and duration of the postpartum period influenced the conception rates of cows bred by TAI and cows bred by combined TAI and natural mating. Cows that conceived from TAI tended to have higher estimated breeding values for fertility than those that conceived from natural mating or did not conceive. Cows with a BCS of 3.00–3.75 had the highest conception rates, followed by those with a BCS >3.75, with cows with a BCS <2.75 having the lowest rates.
(Submitted 4 August 2025; Accepted 19 August 2025; Published 10 October 2025)
References
Agyemang, K., Little, D.A., Bah, M.L., & Dwinger, R.H., 1991. Effects of postpartum body weight changes on subsequent reproductive performance in N’Dama cattle maintained under traditional husbandry systems. Animal Reproduction Science, 26:51–59. DOI: https://doi.org/10.1016/0378-4320(91)90065-8 DOI: https://doi.org/10.1016/0378-4320(91)90065-8
Ayres, H., Ferreira, R.M., Torres-Júnior, J.R.S., Demétrio, C.G.B., Sá Filho, M.F., Gimenes, L.U., Penteado, L., D’Occhio, M.J., & Baruselli, P.S., 2014. Inferences of body energy reserves on conception rate of suckled Zebu beef cows subjected to timed artificial insemination followed by natural mating. Theriogenology, 82:529–536. DOI: https://doi.org/10.1016/j.theriogenology.2014.04.026 DOI: https://doi.org/10.1016/j.theriogenology.2014.04.026
Baruselli, P.S., Reis, E.L., Marques, M.O., Nasser, L.F., & Bó, G.A., 2004a. The use of hormonal treatments to improve reproductive performance of anestrous beef cattle in tropical climates. Animal Reproduction Science, 82–83:479–486. DOI: https://doi.org/10.1016/j.anireprosci.2004.04.025 DOI: https://doi.org/10.1016/j.anireprosci.2004.04.025
Bearden, H.J., Fuquay, J.W., & Willard, S.T., 2006. Applied Animal Reproduction, Sixth Edition, Prentice Hall.
Bennington, C.C., Thayne, W.V., & Thayne, W.V., 1994. Use and misuse of mixed model analysis of variance in ecological studies. Ecology, 75:717–722. DOI: https://doi.org/10.2307/1941729
Burrow, H.M. & Prayaga, K.C., 2004. Correlated responses in productive and adaptive traits and temperament following selection for growth and heat resistance in tropical beef cattle. Livestock Production Science, 86:143–161. DOI: https://doi.org/10.1016/j.livprodsci.2003.06.001 DOI: https://doi.org/10.1016/j.livprodsci.2003.06.001
Busch, D.C., Schafer, D.J., Wilson, D.J., Mallory, D.A., Leitman, N.R., Haden, J.K., Ellersieck, M.R., Smith, M.F., & Patterson, D.J., 2008. Timing of artificial insemination in postpartum beef cows following administration of the h + controlled internal drug-release protocol. Journal of Animal Science, 86:1519–1525. DOI: https://doi.org/10.2527/jas.2008-0925 DOI: https://doi.org/10.2527/jas.2008-0925
Byerley, D.J., Staigmiller, R.B., Berardinelli, J.G., & Short, R.E., 1987. Pregnancy rates of beef heifers bred either on puberal or third estrus. Journal of Animal Science, 65:645–650. DOI: https://doi.org/10.2527/jas1987.653645x DOI: https://doi.org/10.2527/jas1987.653645x
Crowe, M.A., 2008. Resumption of ovarian cyclicity in post-partum beef and dairy cows. Reproduction in Domestic Animals, 43:20–28. DOI: https://doi.org/10.1111/j.1439-0531.2008.01210.x DOI: https://doi.org/10.1111/j.1439-0531.2008.01210.x
Dean, S., 2019. Extending artificial insemination to beef cattle. Farmer’s Weekly, 19 May.
D’Occhio, M.J., Baruselli, P.S., & Campanile, G., 2019. Influence of nutrition, body condition, and metabolic status on reproduction in female beef cattle: A review. Theriogenology, 125:277–284. DOI: https://doi.org/10.1016/j.theriogenology.2018.11.010 DOI: https://doi.org/10.1016/j.theriogenology.2018.11.010
Escrivao, R.J.A., Webb, E.C., Garces, A.P.J.T., & Grimbeek, R.J., 2012. Effects of 48-hour calf withdrawal on conception rates of Bos indicus cows and calf weaning weights in extensive production systems. Tropical Animal Health and Production, 44:1779–1782. DOI: https://doi.org/10.1007/s11250-012-0137-x
Esposito, G., Irons, P.C., Webb, E.C., & Chapwanya, A., 2014. Interactions between negative energy balance, metabolic diseases, uterine health and immune response in transition dairy cows. Animal Reproduction Science, 144:60–71. DOI: https://doi.org/10.1016/j.anireprosci.2013.11.007
Filho, O.G.S., Meneghetti, M., Peres, R.F.G., Lamb, G.C., & Vasconcelos, J.L.M., 2009. Fixed-time artificial insemination with estradiol and progesterone for Bos indicus cows II: Strategies and factors affecting fertility. Theriogenology, 72:210–218. DOI: https://doi.org/10.1016/j.theriogenology.2009.02.008 DOI: https://doi.org/10.1016/j.theriogenology.2009.02.008
Fontes, P.L.P., Oosthuizen, N., & Cliff Lamb, G., 2020. Reproductive management of beef cattle. Mississippi State University Extension, Elsevier. pp. 57–73. DOI: https://doi.org/10.1016/B978-0-12-817052-6.00004-5
Funston, R.N. & Deutscher, G.H., 2004. Comparison of target breeding weight and breeding date for replacement beef heifers and effects on subsequent reproduction and calf performance. Journal of Animal Science, 82:3094–3099. DOI: https://doi.org/10.2527/2004.82103094x DOI: https://doi.org/10.2527/2004.82103094x
Hall, J.B. & Benjamin, R.D., 2005. Timing of insemination of beef heifers. In: Proceedings of Applied Reproductive Strategies in Beef Cattle. pp.195–202.
Humblot, P., Grimard, B., & Ponsart, C., 2009. Impact of energy balance on metabolic changes and reproductive tissues; consequences on fertility in dairy and beef cattle. Cattle Practice, 17(1):5–6. DOI: https://doi.org/10.5661/recadv-08-1
IAEA, 2005. Improving artificial breeding of cattle in Africa, Guidelines and recommendations. Animal Production and Health Section, International Atomic Energy Agency, Vienna, Austria, IAEA-TECDOC-1437. www-pub.iaea.org/MTCD/Publications/PDF/te_1437_web.pdf
Macmillan, K.L., 2002. Advances in bovine theriogenology in New Zealand. 1. Pregnancy, parturition and the postpartum period. New Zealand Veterinary Journal, 50:67–73. DOI: https://doi.org/10.1080/00480169.2002.36272. DOI: https://doi.org/10.1080/00480169.2002.36272
McCrindle, C.M.E., Masethe, J.M., Botha, E.A., Webb, E.C., & Smuts, M.P., 2019. Scrotal tick damage as a cause of infertility in communal bulls in Moretele, South Africa. Journal of the South African Veterinary Association, 90:a1966. DOI: https://doi.org/10.4102/jsava.v90i0.1966 DOI: https://doi.org/10.4102/jsava.v90i0.1966
Murphy, M.G., Boland, M.P., & Roche, J.F., 1990. Activity in post-partum beef suckler cows. Journals of Reproduction and Fertility, 90:523–533. DOI: https://doi.org/10.1530/jrf.0.0900523
Perry, G.A., 2016. Factors affecting puberty in replacement beef heifers. Theriogenology, 86:373–378. DOI: https://doi.org/10.1016/j.theriogenology.2016.04.051 DOI: https://doi.org/10.1016/j.theriogenology.2016.04.051
Pereira, E., De Oliveira, H.N., Eler, J.P., Silva, J.A.I.I.D.V., & Van Melis, M.H., 2006. Use of survival analysis as a tool for the genetic improvement of age at first conception in Nellore cattle. Journal of Animal Breeding and Genetics, 123:64–71. DOI: https://doi.org/10.1111/j.1439-0388.2006.00567.x DOI: https://doi.org/10.1111/j.1439-0388.2006.00567.x
Samadi, F., Phillips, N.J., Blache, D., Martin, G.B., & D’Occhio, M.J., 2013. Interrelationships of nutrition, metabolic hormones and resumption of ovulation in multiparous suckled beef cows on subtropical pastures. Animal Reproduction Science, 137(3–4):137–144. DOI: https://doi.org/10.1016/j.anireprosci.2012.12.012
Rasby, R.J., Stalker, A., & Funston, R.N., 2014. Body Condition Scoring Beef Cows: A Tool for Managing the Nutrition Program for Beef Herds. University of Nebraska-Lincoln Extension, NE, USA. pp. 1–7.
Rice, L.E., 1991. The effects of nutrition on reproductive performance of beef cattle. The Veterinary Clinics of North America. Food Animal Practice, 7:1–26. DOI: https://doi.org/10.1016/S0749-0720(15)30807-0 DOI: https://doi.org/10.1016/S0749-0720(15)30807-0
Renquist, B.J., Oltjen, J.W., Sainz, R.D., & Calvert, C.C., 2006. Effects of age on body condition and production parameters of multiparous beef cows. Journal of Animal Science, 84:1890–1895. DOI: https://doi.org/10.2527/jas.2005-733 DOI: https://doi.org/10.2527/jas.2005-733
Short, R.E., Bellows, R.A., Staigmiller, R.B., Custer, E.E., Ballewos, A., Staigmiller, R.B., & Berardinelli, J.G., 1990. Physiological mechanisms controlling anestrus and infertility in postpartum beef cattle. Journal of Animal Science, 68:799–816. DOI: https://doi.org/10.2527/1990.683799x DOI: https://doi.org/10.2527/1990.683799x
Tainton, N., 2003. Veld management in South Africa. University of KwaZulu Natal Press, KZN, RSA. ISBN 978 0869809488.
Taponen, J., 2009. Fixed-time artificial insemination in beef cattle. Acta Veterinaria Scandinavica, 51:48. DOI: https://doi.org/10.1186/1751-0147-51-48 DOI: https://doi.org/10.1186/1751-0147-51-48
United Nations, 2019. World Population Prospects 2019, Volume II: Demographic Profiles. United Nations Department of Economic and Social Affairs.
Van Dongen, H.P.A., Olofsen, E., Dinges, D.F., & Maislin, G., 2004. Mixed-model regression analysis and dealing with interindividual differences. Methods in Enzymology, 384:139–171. DOI: https://doi.org/10.1016/S0076-6879(04)84010-2 DOI: https://doi.org/10.1016/S0076-6879(04)84010-2
VanRaden, P.M., Sanders, A.H., Tooker, M.E., Miller, R.H., Norman, H.O., Kuhn, M.T., & Wiggans, G.R., 2004. Development of a national genetic evaluation for cow fertility. Journal of Dairy Science, 87:2285–2292. DOI: https://doi.org/10.3168/jds.S0022-0302(04)70049-1 DOI: https://doi.org/10.3168/jds.S0022-0302(04)70049-1
Washaya, S., Tavirimirwa, B., Dube, S., Sisito, G., Tambo, G., Ncube, S., & Zhakata, X., 2019. Reproductive efficiency in naturally serviced and artificially inseminated beef cows. Tropical Animal Health and Production, 51:1963–1968. DOI: https://doi.org/10.1007/s11250-019-01889-z DOI: https://doi.org/10.1007/s11250-019-01889-z
Webb, E.C. & Erasmus, L.J., 2013. The effect of production system and management practices on the quality of meat products from ruminant livestock. South African Journal of Animal Science, 43(3):413–423. DOI: http://dx.doi.org/10.4314/sajas.v43i3.11 DOI: https://doi.org/10.4314/sajas.v43i3.12
Wiltbank, J.N., Rowden, W.W., Ingalls, J.E., Geegoey, K.E., & Koch, R.M., 1962. Effect of energy level on reproductive phenomena of mature Hereford cows. Journal of Animal Science, 21:219–225. DOI: https://doi.org/10.2527/jas1962.212219x DOI: https://doi.org/10.2527/jas1962.212219x
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