Breed effects and heterosis for weight traits and tick count in a cross between an indigenous fat-tailed and a commercial sheep breed

Abstract

Ticks can compromise productivity and welfare in free-ranging sheep. Chemical tick control may not be sustainable in the long term. Alternative control measures must be sought for an integrated control programme. Birth and weaning weights as well as log transformed overall tick count of indigenous fat-tailed Namaqua Afrikaner (NA), commercial Dorper and NA x Dorper cross lambs were studied under extensive conditions. Relative to NA lambs, Dorper lambs were 22.2% heavier at weaning (P < 0.05). Geometric means for total tick count on Dorper lambs exceeded those of their Namaqua Afrikaner contemporaries by more than twofold (P < 0.05). Relative to the pure-breed midparent value, the mean performance of NA x Dorper lambs was 7.9% more for birth weight, 11.2% more for weaning weight and 26.2% less for the back transformed means for total tick count (P < 0.05). Heterosis for total tick count was slightly greater at −29.3% when data were adjusted for the larger size of NA x Dorper lambs. Crossing commercial Dorper sheep with a hardy, indigenous breed therefore resulted in lower levels of tick infestation without compromising live weight in progeny so derived. Hardy, indigenous genetic resources like the NA should be conserved and used in further studies of ovine genetics of resistance to ticks in South Africa.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2

References

  1. Abunna, F., Tura, J. and Regassa, A., 2012. Status of tick infestation in small ruminants of Bedelle district, Oromia region, Ethiopia. Global Veterinaria, 8, 459--462.

    Google Scholar 

  2. Acocks, J.P.H., 1988. Veld Types of South Africa (3rd Edition) Memoirs of the Botanical Survey of South Africa, 57, 1--146. ISBN 0-621-11394-8.

  3. Alessandra, T. and Santo, C., 2012. Tick-borne diseases in sheep and goats: Clinical and diagnostic aspects. Small Ruminant Research 106S, S6--S11.

    Article  Google Scholar 

  4. Ayres, D.R., Pereira, R.J., Boligon, A.A., Baldi, F., Roso, V.M. and Albuquergue, L.G., 2015. Genetic parameters and investigation of genotype x environment interactions in Nellore x Hereford crossbred for resistance to cattle ticks in different regions of Brazil. Journal of Applied Genetics, 56, 107--113.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  5. Borg, R.C., 2007. Phenotypic and genetic evaluation of fitness characteristics in sheep under a range environment. PhD Thesis, Virginia Polytechnic Institute and State University, Blacksberg VA, USA.

    Google Scholar 

  6. Brossard, M., 1998. The use of vaccines and genetically resistant animals in tick control. Revue Scientifique et Technique (International Office of Epizootics), 17, 188--199.

    CAS  Google Scholar 

  7. Budeli, M.A., Nephawe, K.A., Norris, D., Selapa, N.W., Bergh, L. and Maiwashe, A., 2009. Genetic parameter estimates for tick resistance in Bonsmara cattle. South African Journal of Animal Science, 39, 321--327.

    Google Scholar 

  8. Burger, A., Hoffman, L.C., Cloete, J.J.E., Muller, M. and Cloete, S.W.P., 2013. Carcass composition of Namaqua Afrikaner, Dorper and SA Mutton Merino ram lambs reared under extensive conditions. South African Journal of Animal Science, 43, S28--S32.

    Google Scholar 

  9. Burrow, H.M., 2001. Variances and covariances between productive and adaptive traits and temperament in a composite breed of tropical beef cattle. Livestock Production Science, 70, 213--233.

    Article  Google Scholar 

  10. Cloete, S.W.P. and De Villiers, T.T., 1987. Production parameters for a commercial Dorper flock on extensive pastures. South African Journal of Animal Science, 17, 121--127.

    Google Scholar 

  11. Cloete, S.W.P. and Olivier, J.J., 2010. South African Sheep and Wool Industries. In: The International Sheep and Wool Handbook. Ed. D.J. Cottle. Nottingham University Press, Manor Farm, Thrumpton, Nottingham NG11 0AX, United Kingdom. pp 95--112.

    Google Scholar 

  12. Cloete, J.J.E., Cloete, S.W.P., Scholtz, A.J. and Matthee, S., 2013. The effect of breed, ewe age and season on tick counts of indigenous and commercial sheep in South Africa. Proceedings of the Association for the Advancement of Animal Breeding and Genetics, 20, 187--190.

    Google Scholar 

  13. Cloete, S.W.P., Olivier, J.J., Sandenbergh, L. and Snyman, M.A., 2014. The adaption of the South African sheep industry to new trends in animal breeding and genetics: A review. South African Journal of Animal Science, 44, 308--321.

    Google Scholar 

  14. Cloete, S.W.P., Cloete, J.J.E. and Scholtz, A.J., 2016. Genetic parameters for tick count and udder health in commercial and indigenous ewes in South Africa. Veterinary Parasitology, 230, 33--42.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  15. Corbet, N.J., Shepherd, R.K., Burrow, H.M., Van der Westhuizen, J., Strydom, P.E. and Bosman, D.J., 2006. Evaluation of Bonsmara and Belmont Red cattle breeds in South Africa. 1. Productive performance. Australian Journal of Experimental Agriculture, 46, 199--212.

    Article  Google Scholar 

  16. De la Fuente, J., Moreno-Cid, J.A., Canales, M., de la Lastra, J.M.P., Kocan, K.M., Galindo, R.C., Almazán, C. and Blouin, E.F., 2011. Targeting arthropod subolesin/akirin for the development of a universal vaccine for control of vector infestations and pathogen transmission. Veterinary Parasitology, 181, 17--22.

    PubMed  Article  CAS  PubMed Central  Google Scholar 

  17. Dreyer, K., Fourie, L.J. and Kok, D.J., 1997. Predation of livestock ticks by chickens as a tick-control method in a resource-poor urban environment. Onderstepoort Journal of Veterinary Research, 64, 273--276.

    CAS  Google Scholar 

  18. El Fadili, M. and Leroy, P.L., 2001. Estimation of additive and non-additive genetic parameters for reproduction, growth and survival traits in crosses between the Moroccan D'man and Timahdite sheep breeds. Journal of Animal Breeding and Genetics, 118, 341--353. https://doi.org/10.1046/j.1439-0388.2001.00297.x|

    Article  Google Scholar 

  19. Emsen, E., 2005. Testicular development and body weight gain from birth to 1 year of age of Awassi and Redkaraman sheep and their reciprocal crosses. Small Ruminant Research, 59, 79--82.

    Article  Google Scholar 

  20. Fogarty, N.M., 2006. Utilization of breed resources for sheep production. Proceedings of the 7th World Congress on Genetics Applied to Livestock Production, Bello Horizonte, Brazil. Communication 04-10.

  21. Fourie, L.J. and Kok, D.J., 1996. Seasonal dynamics of the Karoo paralysis tick (Ixodes rubicundus): a comparative study on Merino and Dorper sheep. Onderstepoort Journal of Veterinary Research, 63, 273--276.

    CAS  Google Scholar 

  22. Garcia, M.V., Andreotti, R., Reis, F.A., de Abreu Rangel Aguirre, A., Barros, J.C., Matias, J., Koller, W.W., 2014. Contributions of the hair sheep breed Santa Ines as a maintenance host for Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) in Brazil. Parasites and Vectors 7, 515.

    PubMed  PubMed Central  Google Scholar 

  23. Gbolagunte, G.D., Hambolu, J.O. and Akpavie, S.O., 2009. Pathology and leather surface appearance of disease afflicted Nigerian small ruminant skins. Assumption University Journal of Technology, 12, 272--281. (Technical Report). http://www.library.au.edu/Au-Journal-of-Technology/v12-n4-7.pdf

  24. Gilmour, A.R., Gogel, B.J., Cullis, B.R. and Thompson, R., 2015. ASReml User Guide, Release 3.0. VSN International Ltd, Hemel Hempstead, HP1 1ES, UK. www.vsni.co.uk.

  25. Gothe, R. and Bezuidenhout, J.D., 1986. Studies on the ability of different strains or populations of female Rhipicephalus evertsi evertsi (Acarina: Ixodidae) to produce paralysis in sheep. Onderstepoort Journal of Veterinary Research, 53, 19--24.

    CAS  Google Scholar 

  26. Grøva, L., Sae-Lim, P. and Olesen, I., 2014. Genetic parameters of tick-infestation on lambs of the Norwegian White sheep breed. Proceedings of the 10th World Congress on Genetics Applied to Livestock Production. https://asas.org/docs/default-source/wcgalp-posters/546_paper_9822_manuscript_974_0.pdf?sfvrsn=2. Accessed on 4 June 2015.

  27. Howell, C.J., Walker, J.B. and Nevill, E.M., 1978. Ticks, mites and insects infesting domestic animals in South Africa. Part 1. Description and biology. Scientific Bulletin no.393, Department of Agricultural Technical Services, Republic of South Africa, 393, 69pp.

  28. Hurtado, A., Barandika, J.F., Oporto, B. and Minguijón, E., 2015. Risks of suffering tick-borne diseases in sheep translocated to a tick infested area: A laboratory approach for the investigation of an outbreak. Ticks and Tick-borne Diseases, 6, 31--37.

    PubMed  Article  PubMed Central  Google Scholar 

  29. Jalil-Sarghale, A., Kholghi, M., Shahrebabak, M.M., Shahrebabak, H.M., Mohammadi, H. and Abdollahi-Arpanahi, R., 2014. Model comparisons and genetic parameter estimates of growth traits in Baluchi sheep. Slovak Journal of Animal Science, 47, 12--18.

    Google Scholar 

  30. Kaaya, G.P., Mwangi, E.N. and Ouna, E.A., 1996. Prospects for biological control of livestock ticks, Rhipicephalus appendiculatus and Amblyomma variegatum, using the entomogenous fungi Beauveria bassiana and Metarhizium anisopliae. Journal of Invertebrate Pathology, 67, 15--20.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  31. Kaaya, G.P., Samish, M. and Glazer, I., 2000. Laboratory evaluation of pathogenicity of entomopathogenic nematodes of African tick species. Annals of the New York Academy of Sciences, 916, 303--308.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  32. Kaaya, G.P., Samish, M., Hedimbi, M., Gindin, G. and Glazer, I., 2011. Control of tick populations by spraying Metarhizium anisopliae conidia on cattle under field conditions. Experimental and Applied Acarology, 55, 273--281.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  33. Kok, D.J. and Fourie, L.J., 1995. The role of Hyalomma ticks in foot infestations and temporary lameness of sheep in a semi–arid region of South Africa. Onderstepoort Journal of Veterinary Research, 62, 201--206.

    CAS  Google Scholar 

  34. Kok, O.B. and Petney, T.N., 1993. Small and medium sized mammals as predators of ticks (Ixodoidea) in South Africa. Experimental and Applied Acarology, 17, 733--740.

    CAS  PubMed  PubMed Central  Google Scholar 

  35. Latif, A.A., 1984. Resistance to natural tick infestations in different breeds of cattle in the Sudan. International Journal of Tropical Insect Science, 5, 95--97.

    Article  Google Scholar 

  36. MacIvor, K.M. and Horak I.G., 1987. Foot abscess in goats in relation to the seasonal abundance of adult Ablyomma herbraeum and adult Rhipicephalus glabroscutatum (Acari: Ixodidae). Journal of the South African Veterinary Association, 58, 113--118.

    CAS  PubMed  PubMed Central  Google Scholar 

  37. MacLeod, J., 1932. The bionomics of Ixodes ricinus L., the “sheep tick” of Scotland. Parasitology, 24, 382--400. https://doi.org/10.1017/S0031182000020795.

    Article  Google Scholar 

  38. Madalena, F.E., 2019. Bos indicus breeds and Bos indicus × Bos taurus crosses. In: F.E. Madalena, H. Toledo-Alvarado and N. Cala-Moreno (eds). Reference Module in Food Science, Chapter: Animals that Produce Dairy Foods, Elsevier, https://doi.org/10.1016/B978-0-08-100596-5.00619-3 (Accessed on 4 May 2020).

  39. Marufu, C.M., Qokweni, L., Chimonyo, M. and Dzama, K., 2011. Relationships between tick counts and coat characteristics in Nguni and Bonsmara cattle reared on semiarid rangelands in South Africa. Ticks and Tick-borne Diseases, 2, 172--177.

    PubMed  Article  PubMed Central  Google Scholar 

  40. Mirkena, T., Duguma, G., Haile, A., Tibbo, M., Okeyo, A.M., Wurzinger, M. and Sölkner, J., 2010. Genetics of adaptation in domestic farm animals: A review. Livestock Science, 132, 1--12.

    Article  Google Scholar 

  41. Molotsi, A.H., Dube, B. and Cloete, S.W.P., 2020. The current status of indigenous ovine genetic resources in Southern Africa and future sustainable utilisation to improve livelihoods. Diversity, 12, 14. https://doi.org/10.3390/d12010014

    Article  Google Scholar 

  42. Mustafa, B.H.S., 2013. Level of zinc and some blood phenomena in sheep infested naturally with hard tick (Ixodidae) in Sulaimani province – Iraq. Al-Anbar Journal of Veterinary Science, 6, 32--38.

    Google Scholar 

  43. Mwangi, E.N. and Kaaya, G.P., 1997. Prospects of using tick parasitoids (insect) for tick management in Africa. International Journal of Acarology, 23, 215--219.

    Article  Google Scholar 

  44. Mwangi, E.N., Hassan, S.M., Kaaya, G.P. and Essuman, S., 1997. The impact of Ixodiphagus hookeri, a tick parasitoid, on Amblyomma varigatum (Acari: Ixodidae) in a field trial in Kenya. Experimental and Applied Acarology, 21, 117--126.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  45. Neser, F.W.C., Konstantinov, K.V. and Erasmus, G.J., 1995. Estimated genetic trends in three Dorper lines with different selection criteria. South African Journal of Animal Science, 25, 65--69.

    Google Scholar 

  46. Nolan, J., 1990. Acaricide resistance in single and multi-host ticks and strategies for control. Parassitologia, 32, 145--153.

    CAS  PubMed  PubMed Central  Google Scholar 

  47. Noor, R.R., Djajanegara, A. and Schüler, L., 2001. Selection to improve birth and weaning weight of Javanese fat tailed sheep. Archiv für Tierzucht, 6, 649--659.

    Google Scholar 

  48. Obst, J.M., Boyes, T. and Channiago, T., 1980. Reproductive performance of Indonesian sheep and goats. Proceedings of the Australian Society of Animal Production, 13, 321--324.

    Google Scholar 

  49. Peters, F., Kotze, A., Van der Bank, F.H. and Grobler, J.P., 2010. Genetic profile of the locally developed Meatmaster sheep breed in South Africa based on microsatellite analysis. Small Ruminant Research, 90, 101--108.

    Article  Google Scholar 

  50. Petney, T.N. and Kok, O.B., 1993. Birds as predators of ticks (Ixodoidea) in South Africa. Experimental and Applied Acarology, 17, 393--403.

    Article  Google Scholar 

  51. Piper, E.K., Jackson, L.A., Bagnall, N.H., Kongsuwan, K.K., Lew, A.E. and Jonsson, N.N., 2008. Gene expression in the skin of Bos taurus and Bos indicus cattle infested with the cattle tick, Rhipicephalus (Boophilus) microplus. Veterinary Immunology and Immunopathology, 126, 110--119.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  52. Qwabe, S.O., 2011. Genetic and phenotypic characterization of the South African Namaqua Afrikaner sheep breed. Master’s degree Thesis, University of Pretoria, Pretoria, South Africa.

  53. Qwabe, S.O., Van Marle-Köster, E. and Visser, C., 2012. Genetic diversity and population structure of the endangered Namaqua Afrikaner sheep. Tropical Animal Health and Production, 45, 511--516.

    PubMed  Article  PubMed Central  Google Scholar 

  54. Regitano, L.C.A., Ibelli, A.M.G., Gasparin, G., Miyata, M., Azevedo, A.L.S., Coutinho, L.L., Teodoro, R.L., Machado, M.A., Silva, M.V.G.B., Nakata, L.C., Zaros, L.G., Sonstegard, T.S., Silva, A.M., Alencar, M.M. and Oliveira, M.C.S., 2008. On the search for markers of tick resistance in Bovines. In: M-H. Pinard, C. Gay, P-P. Pastoret, and B. Dodet (eds), Proceedings of the International Symposium on Animals Genomics for Animal Health, Paris, October 2007. Developments in Biologicals (Basel). Basel, Karger, 132, 225--230.

    Google Scholar 

  55. Rekwot, P.I., Ogwu, D., Oyepide, E.O. and Sekoni, V.O., 2001. The role of pheromones and biostimulation in animal reproduction. Animal Reproduction Science, 65, 157--170..

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  56. Riek, R.F., 1962. Studies on the reactions of animals to infestation with ticks. VI. Resistance of cattle to infestation with the tick Boophilus microplus (Canestrini). Australian Journal of Agricultural Research, 13, 532--550. https://doi.org/10.1071/AR9620532. (Accessed online on 4 May 2020).

    Article  Google Scholar 

  57. Rosov, A. and Gootwine, E., 2013. Birth weight, and pre- and postweaning growth rates of lambs belonging to the Afec-Assaf strain and its crosses with the American Suffolk. Small Ruminant Research, 113, 58--61.

    Article  Google Scholar 

  58. Sae-Lim, P., Grøva, L., Olesen, I. and Verona, L., 2017. A comparison of nonlinear mixed models and response to selection of tick-infestation on lambs. PLOS One, 12, e0172711. https://doi.org/10.1371/journal.pone.0172711.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  59. Safari, E., Fogarty, N.M. and Gilmour, A.R., 2005. A review of genetic parameter estimates for wool, growth, meat and reproduction traits in sheep. Livestock Production Science, 92, 271--289.

    Article  Google Scholar 

  60. Safari, E., Fogarty, N.M., Gilmour, A.R., Atkins, K.D., Mortimer, S.I., Swan, A.A., Brien, F.D., Greeff, J.C. and Van der Werf, J.H.J., 2007. Across population genetic parameters for wool, growth and reproduction traits in Australian Merino sheep. 1. Data structure and non-genetic effects. Australian Journal of Agricultural Research, 58, 169--175.

    Article  Google Scholar 

  61. Sandenbergh, L., Cloete, S.W.P. and Olivier, J.J., 2018. Assessing the occurrence of hybridisation in endangered indigenous sheep. Proceedings of the 11th World Congress on Genetics Applied to Livestock Production, 11 – 16 February, Auckland, New Zealand. 11.725. http://www.wcgalp.org/system/files/proceedings/2018/assessing-occurrence-hybridisation-endangered-indigenous-sheep.pdf (Accessed on 4 January 2021)

  62. Schwalbach, L.M.J., Greyling, J.P.C. and David, M., 2003. The efficacy of a 10% aqueous Neem (Azadirachta indica) seed extract for tick control in Small East African and Toggenburg female goat kids in Tanzania. South African Journal of Animal Science, 33, 83--88.

    Google Scholar 

  63. Seifert, G.W., 1971. Variations between and within breeds of cattle in resistance to field infestations of the cattle tick (Boophilus microplus). Australian Journal of Agricultural Research, 22, 159--168.

    Article  Google Scholar 

  64. Simitzis, P.E., Deligeorgis, S.G. and Bizelis, J.A., 2006. Effect of breed and age on sexual behaviour of rams. Theriogenology, 65, 1480--1491.

    PubMed  Article  PubMed Central  Google Scholar 

  65. Snyman, M.A., van Marle-Kőster, E., Qwabe, S.O. and Visser, C., 2013. Genetic and phenotypic profile of three South African Namaqua Afrikaner sheep flocks. Grootfontein Agric 13. http://gadi.agric.za/Agric/Vol13No1_2013/namaqua.php. Accessed on 28 April 2020.

  66. Stuen, S., 2016. Haemoparasites in small ruminants in European countries: Challenges and clinical relevance. Small Ruminant Research, 142, 22--27.

    Article  Google Scholar 

  67. Stuen, S., Grøva, L., Granquist, E.G., Sandstedt, K., Olesen, I. and Steinshamn, H., 2011. A comparative study of clinical manifestations, haematological and serological responses after experimental infection with Anaplasma phagocytophilum in two Norwegian sheep breeds. Acta Veterinaria Scandinavica, 53, 8. https://actavetscand.biomedcentral.com/track/pdf/10.1186/1751-0147-53-8.pdf

    PubMed  PubMed Central  Article  Google Scholar 

  68. Torina, A., Moreno-Cid, J.A., Blanda, V., Fernández de Mera, I.G., Pérez de la Lastra, J.M., Scimeca, S., Blanda, M., Scariano, M.E., Briganò, S., Disclafani, R., Piazza, A., Vicente, J., Gortázar, C., Caracappa, S., Lelli, R.C. and de la Fuente, J., 2014. Control of tick infestations and pathogen prevalence in cattle and sheep farms vaccinated with the recombinant Subolesin-Major Surface Protein 1a chimeric antigen. Parasites and Vectors, 7, 10. http://www.parasitesandvectors.com/content/7/1/10

    PubMed  Article  CAS  PubMed Central  Google Scholar 

  69. Utech, K.B.W., Seifert, G.W. and Wharton, R.H., 1978. Breeding Australian Illawarra Shorthorn cattle for resistance to Boophilus microplus. I. Factors affecting resistance. Australian Journal of Agricultural Research, 29, 411--422.

    Article  Google Scholar 

  70. Van der Merwe, D.A., Brand, T.S. and Hoffman, L.C., 2019. Application of growth models to different sheep breed types in South Africa. Small Ruminant Research, 178, 70--78.

    Article  Google Scholar 

  71. Van der Merwe, D.A., Brand, T.S. and Hoffman, L.C., 2020. Slaughter characteristics of feedlot-finished premium South African lamb: effects of sex and breed type. Foods 9, 648; https://doi.org/10.3390/foods9050648.

    CAS  Article  PubMed Central  Google Scholar 

  72. Van Marle-Köster, E., Visser, C., Makgahlela, M. and Cloete, S.W.P., 2015. Genomic technologies for food security. A review of challenges and opportunities in southern Africa. Food Research International, 76, 971--979.

    Article  Google Scholar 

  73. Wambura, P.N., Gwakisa, P.S., Silayo, R.S. and Rugaimukamu, E.A., 1998. Breed-associated resistance to tick infestation in Bos indicus and their crosses with Bos taurus. Veterinary Parasitology, 77, 63--70.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  74. Willadsen, P., 2004. Anti-tick vaccines. Parasitology, 129, S367--S387.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  75. Willadsen, P., Smith, D., Cobon, G. and McKenna, R.V., 1996. Comparative vaccination of cattle against Boophilus microplus with recombinant antigen Bm86 alone or in combination with recombinant Bm91. Parasite Immunology, 18, 241--246.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  76. Wood, M.D., Culling, B., Culling, C. and Schwantje, H.M., 2010. Winter tick infestation and associated hair loss on Stone’s Sheep in Northern British Columbia. In: V. Bleich and D. Whittaker (eds). Proceedings of the 17th Biennial Symposium. Northern Wild Sheep and Goat Council, June 7 - 11, 2010, Hood River, Oregon, USA. http://media.nwsgc.org/proceedings/MWSGC-2010/Wood%20et%20al%202012%20110.pdf (Accessed online on 4 May 2020).

Download references

Acknowledgements

The contribution of Mr G.G. Rheeder and the staff at Nortier to the maintenance and recording of the resource flock is acknowledged with gratitude.

Funding

The research reported in this paper was funded jointly by the South African Wool Industry, the Western Cape Agricultural Research Trust (Project Cloete - 0050) and the THRIP initiative of the National Research Foundation (Projects TP2010072100062 and TP13082129837). The Intra-ACP academic mobility scheme and NRF are also acknowledged for financially supporting the study of K. Thutwa.

Author information

Affiliations

Authors

Corresponding author

Correspondence to S. W. P. Cloete.

Ethics declarations

Conflict of interest

The authors declare no competing interests.

Statement of animal rights

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Ethical clearance for the project was obtained from the Departmental Ethical Committee for Research on Animals (DECRA reference number R13/88) in the Department of Agriculture, Western Cape Government.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Cloete, S.W.P., Thutwa, K., Scholtz, A.J. et al. Breed effects and heterosis for weight traits and tick count in a cross between an indigenous fat-tailed and a commercial sheep breed. Trop Anim Health Prod 53, 165 (2021). https://doi.org/10.1007/s11250-021-02612-7

Download citation

Keywords

  • Dorper
  • Namaqua Afrikaner
  • Indigenous
  • Resistance
  • Tolerance
  • Conservation