Estimation of Inbreeding and Its Effects on Growth Traits in Sangsari Sheeps

Document Type : Genetics & breeding

Authors

• Mahboobeh Mirzaee ilaly ¹
• Saeed Hassani ¹
• Mojtaba Ahani Azari ²
• Rohullah Abdullahpour ³
• Sakineh Naghavian ¹

¹ Gorgan University of Agricultural Science and Natural Resources

² Department of Animal and Poultry Breeding and Genetics, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran

³ Qaemshahr Islamic Azad University

10.22067/ijasr.v9i1.54124

Abstract

Introduction The aim of this study was to estimate inbreeding coefficient in Sangsari sheep and its impact on growth traits in order to manage breeding programs and preventing possible negative and harmful effects of excessive increase of inbreeding. Inbreeding is the mating of individuals whose relatedness is greater than the average degree of relationship exists in the population and capable of changing the genotypic frequencies of a population without modifying the gene frequencies. Increase in inbreeding can lead to reduced response to selection of economic traits and the heterozygosity and consequently leads to increase in homozygosity and loss of genetic diversity. Inbreeding also impairs growth, production, health, reproduction and survival of inbred animals. A complete pedigree is also necessary for accurate evaluation of inbreeding and other important population parameters.
Materials and Methods In the present study, data from 7028 Sangsari sheep (3180 males and 3848 females) which were collected during 28years (1987-2014) in the breeding station of Sangsari sheep located near to Damghan city, Semnan province, were used to estimate inbreeding coefficients and its effects on birth weight (BW), weaning weight (WW), 6 month weight (6MW), 9 month weight (9MW) and yearling weight (YW) of animals. Pedigree information for each lamb included animal, sire, and dam and also sex, birth date, type of birth, age of dam and record of studied traits. In order to edit data, FoxPro software (FoxPro 2.6) and to study of fixed effects on growth traits, GLM procedure of SAS 9.1 were used. Before estimation of inbreeding, it is very important to be sure about completeness and depth of the pedigree. In order to estimate inbreeding coefficients of all animals in the pedigree and to determine the population structure, CFC based on Meuwissen and Luo algorithm and Endog v4.8 softwares, were used. The regression of the studied traits on inbreeding coefficient was estimated using WOMBAT software by restricted maximum likelihood method and 12 animal models were used. The most appropriate model for each trait was determined based on Akaike’s information criterion.
Results and Discussion Of all the registered animals, 4772 animals had both parent known. Completeness of the first and second ancestor generations of all animals were 78.52% and 44.33%, respectively, and the completeness decreased progressively for the next generations. The average equivalent complete generation, as a measure of pedigree completeness level, estimated as 1.59. In the studied pedigree, A low proportion of the recorded lambs (7.21percent of the total lambs) were inbred and their average inbreeding coefficients was 3.88 percent. Mean inbreeding of the total population and average relatedness estimated as 0.28% and 0.59%, respectively. In the early years, the number of inbred animals was low, but over time, the average coefficient of inbreeding increased due to the selection of breeding male and female animals within the flock and mating of the related animals and inbreeding coefficient was increased by 0.028 percent per year and was statistically significant. Maximum and minimum inbreeding coefficients were 31.25 percent and 0.024 percent, respectively, in inbred population. Low average coefficient of inbreeding can be mostly due to controlled mating in the flock and also due to having many animals with inbreeding coefficients of zero. Zero inbreeding coefficients were mainly due to lack of pedigree information in the early years. Effects of inbreeding on growth traits were estimated by restricted maximum likelihood method using 12 animal models. The most appropriate model for each trait was determined based on Akaike’s Information Criterion. The regression coefficients of inbreeding on birth weight (model 11), weaning weight (model 8), 6 month weight (model 11), 9 month weight (model 9) and yearling weight (model 3) were -1.46, -7.72, 14.87, 20.92 and -29.46 gram, respectively, which were not statistically significant.
Conclusion Generally, results indicated that the average coefficient of inbreeding in the studied Sangsari sheep population was lower than the values reported in other breeds which could be because of lack of clear information of some parents and common ancestors and also because of the purposive and largely controlled matings therefore there is no serious problem of inbreeding and its effects on body weights in this population, but in order to prohibit the animals with high inbreeding levels, pedigree information has to be considered during mating.

Keywords

• Body weights
• Inbreeding coefficient
• Sheep
• Structure of population

20.1001.1.20083106.1396.9.1.12.8

---

References

1- Adeli Khah, M. H., R. Vaez Torshizi., M. Rokouei, and D. Tohidi. 2008. Inbreeding and its effects on production traits Iranian Zandi sheep. 3rd Congress on Animal Science, Mashhad, Iran. (In Persian).

2- Akaike, H. 1974. A new look at the statistical model identification. IEEE Transactions on Automatic Control, 19(6): 716–723.

3- Almasi, M., A. Rashidi., M. Razmkabir, and M. M. Gholam Babaeian. 2014. Estimation of inbreeding coefficient and its effects on growth traits in Zandi sheep. Journal of Ruminant Research, 2(3): 109-119. (In Persian).

4- Bahri Binabaj, F., H. Faraji Arough., M. Rokuei., M. Jafari, and M. R. Sheikhloo. 2015. Estimation of inbreeding depression on growth correlated traits in Karakul lambs. Journal of Ruminant Research, 2(4): 137-156. (In Persian).

5- Bijma, P., J. A. M. Van Arendonk, and J. A. Woolliams. 2001. Predicting rates of inbreeding for livestock improvement schemes. Journal of Animal Science, 79: 840-853.

6- Cassell, B. G., V. Adamec, and R. E. Pearson. 2003. Effects of incomplete pedigree on estimates of inbreeding and inbreeding depression for days to first service and summit milk yield in Holsteins and Jerseys. Journal of Dairy Science, 86: 2967–2976.

7- Dickerson, G. E. 1963. Experimental evaluation of selection theory in poultry. Pages 747-761 in Genetics Today International Congress of Genetics. Hague, Holand.

8- Dorostkar, M., H. Faraji Arough., J. Shodja., S. A. Rafat., M. Rokouei, and H. Esfandyari, 2012. Inbreeding and inbreeding depression in Iranian Moghanisheep breed. Journal of Agricultural Science and Technology, 14: 549-556.

9- Eteqadi, B., N. Ghavi Hossein Zadeh, and A. A. Shadparvar. 2014. Population structure and inbreeding effects on body weight traits of Guilan sheep in Iran. Small Ruminant Research, 119: 45-51.

10- Farhangfar, H. and Gh. Mottaghinia. 2013. A study on the effect of inbreeding depression on growth traits in Baluchi Sheep. Research on Animal Production, 4(7): 92-105. (In Persian).

11- Falconer, D. S, and T. F. C. Mackay. 1996. Introduction to Quantitative Genetics. Longman Group Ltd., England.

12- Gilmour, A. R., B. J. Gogel., B. R. Cullis, and R. Thompson. 2009. ASReml User Guide Release 4.0 VSN International Ltd, Hempstead, HP1 1ES, UK.

13- Goyache, F., J. P. Gutierrez., I. Fernandez, E. Gomes., I. Alvarez, J. Diez, and L. J. Roy. 2003. Using pedigree information to monitor genetic variability of endangered population: the Xalda sheep breed of Asturias as an example. Journal of Animal Breeding and Genetics, 120: 95–105.

14- Gowane, G. R., V. Prakash., A. Chopra, and L. L. L. Prince. 2013. Population structure and effect of inbreeding on lamb growth in Bharat Merino sheep. Small Ruminant Research, 114: 72-79.

15- Gulisija, D., D. Gianola., K. A. Weigel, and M. A. Toro. 2006. Between-founder heterogeneity in inbreeding depression for production in Jersey cows. Livestock Science, 104: 244–253.

16- Gutierrez, J. P. and F. Goyache. 2005. A note on ENDOG: a computer program for analyzing pedigree information. Journal of Animal Breeding and Genetics, 122: 172–176.

17- Gutierrez, J. P., J. Altarriba., C. Diaz., R. Quintanilla., J. Canon, and J. Piedrafita. 2003. Genetic analysis of eight Spanish beef cattle breeds. Genetics Selection Evolution, 35: 43–64.

18- Hedrick, O. W, and S. T. Kalinowski. 2000. Inbreeding depression in conservation biology. Annual Review of Ecological Systems, 31: 139-162.

19- Hussain, A., P. Akhtar., S. Ali., M. Younas, and K. Javed. 2006. Inbreeding effects on post-weaning growth traits of Thallisheep in Pakistan. Pakistan Journal of Agricultural Sciences, 43(1-2): 89-92.

20- Jafari, Sh., A. Hashemi., I. Bernousi., S. Razzaghzadeh. 2011. The effect of inbreeding coefficient on pre-weaning weight and wool traits in a flock of Makuie sheep. National Conference on Modern Agricultural Sciences & Technologies. Zanjan, Iran. (In Persian).

21- Kosgey, I. S, and A. M. Okeyo. 2007. Genetic improvement of small ruminantsin low-input, smallholder production systems: technical and infra-structural issues. Small Ruminant Research, 70: 76–88.

22- Lush, J. L. 1945. Animal Breeding Plans. Iowa State College Press, Ames, Iowa, USA.

23- Lutaaya, E., I. Misztal., J. K. Bertrand, and J. W. Mabry. 1999. Inbreeding in populations with incomplete pedigree. Journal of Animal Breeding and Genetics, 116: 475–480.

24- MacCluer, J. W., A. J. Boyce., B. Dyke., L. R. Weitkamp., D. W. Pfenning, and C. J. Parsons. 1983. In breeding and pedigree structure in Standardbred horses. Journal of Heredity, 74: 394-399.

25- Maignel, L., D. Boichard, and E. Verrier. 1996. Genetic variability of French dairy breeds estimated from pedigree information. Interbull Bulletin, 14: 49–54.

26- Mandal, A., K. P. Pant., D. R. Notter., P. K. Rout., R. Roy., N. K. Sinha, and N. Sharma. 2005. Studies on inbreeding and its effects on growth and fleece traits of Muzaffarnagari sheep. Asian-Australasian Journal of Animal Sciences, 18(10): 1363–1367.

27- Martinez R. A., D. Garcia., J. L. Gallego., G. Onofre., J. Perez, and J. Ca˜non. 2008. Genetic variability in Colombian Creole cattle populations estimated by pedigree information. Journal of Animal Science, 86: 545–552.

28- Mirzamohamadi, E., A. Rashidi., M. Vatankhah, and M. Jafari. 2012. Evaluation of inbreeding effects on pre-weaning growth traits and lamb survival in Iran-black sheep. Animal Sciences Journal, 101: 62-70. (In Persian).

29- Mokhtari, M. S., M. MoradiShahrbabak., A. K. Esmailizadeh., R. Abdollahi-Arpanahi, and J. P. Gutierrez. 2013. Genetic diversity in Kermani sheep assessed from pedigree analysis. Small Ruminant Research, 114: 202–205.

30- Mokhtari, M. S., M. MoradiShahrbabak, A. K. Esmailizadeh., R. Abdollahi-Arpanahi, and J. P. Gutierrez. 2014. Pedigree analysis of Iran Black sheep and inbreeding effects on growth and reproduction traits. Small Ruminant Research, 116: 14– 20.

31- Mohammadi, K., A. Rashidi., M. S. Mokhtari, and M. T. Beigi Nassiri. 2011. The estimation of (co)variance components for growth traits and Kleiber ratios in Zandisheep. Small Ruminant Research, 99: 116-121.

32- Meuwissen, T. H. E. and Z. Luo. 1992. Computing inbreeding coefficient in large populations. Genetics Selection Evolution, 24: 305–313.

33- Meyer, K. 2006. WOMBAT–A Program for Mixed Model Analyses by Restricted Maximum Likelihood. User Notes. Animal Genetics and Breeding Unit, Armidale.

34- Norberg, E. and A. C. Sørensen. 2007. Inbreeding trend and inbreeding depression in the Danish populations of Texel, Shropshire, and Oxford Down. Journal of Animal Science, 85: 299-257.

35- Pedrosa, V. B., Jr. M. L. Santana., P. S. Oliveira., J. P. Eler, and J. B. S. Ferraz. 2010. Population structure and inbreeding effects on growth traits of SantaInês sheep in Brazil. Small Ruminant Research, 93: 135–139.

36- Rzewuska, K., J. Klewiec, and E. Martyniuk. 2005. Effect of inbred on reproduction and body weight of sheep in a closed Booroola flock. Animal Science Papers and Reports, 4: 237–247.

37- Rashedi Dehsahraei, A., J. Fayazi, and M. Vatankhah. 2013. Investigating inbreeding trend and its impact on growth traits of Lori-Bakhtiari Sheep. Journal of Ruminant Research, 1(3): 65-78. (In Persian).

38- Rashidi, A., S. C. Bishop, and O. Matika. 2011. Genetic parameter estimates for pre-weaning performance and reproduction traits in Markhoz goats. Small Ruminant Research, 100: 100-106.

39- Rodrigañez, J., M. A. Toro., M. C. Rodrigañez, and L. Silio. 1998. Effect of founder allele survival and inbreeding depression on litter size in closed line of Large White pigs. Journal of Animal Science, 67: 573–582.

40- SAS Institute. 2003. SAS 9.1.3 Help and Documentation, Cary, NC: SAS Institute Inc.

41- Sargolzaei, M., H. Iwaisaki, and J. J. Colleau. 2006. CFC: A tool for monitoring genetic diversity. Pages 27-28 in Proc. 8th World Congress on Genetic Applied to Livestock Production. Belo Horizonte, Minas Gerais, Brazil.

42- Selvaggi M., C. Darioa., V. Peretti., F. Ciotolac., D. Carnicellaa, and M. Darioa. 2010. Inbreeding depression in Leccese sheep. Small Ruminant Research, 89: 42–46.

43- Sheikhloo, M., M. Tahmoorespur, and A. A. Aslaminejad. 2012. A study of inbreeding of Baluchi sheep in Abbas Abad breeding center of Mashhad. Iranian Journal of Animal Science Research, 3(4): 453-458. (In Persian).

44- Tahmoorespur, M. and M. Sheikhloo. 2011. Pedigree analysis of the closed nucleus of Iranian Baluchi sheep. Small Ruminant Research, 99: 1–6.