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Analysis of lambing distribution in the Ripollesa sheep breed. II. Environmental and genetic sources of variation

Published online by Cambridge University Press:  06 March 2019

J. Casellas Open the ORCID record for J. Casellas [Opens in a new window] ,
S. Id-Lahoucine  and
M. Martín de Hijas-Villalba
J. Casellas*
Affiliation:
Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
S. Id-Lahoucine
Affiliation:
Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain Department of Animal Biosciences, Centre for Genetic Improvement of Livestock, University of Guelph, Guelph, ON, Canada N1G 2W1
M. Martín de Hijas-Villalba
Affiliation:
Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
*
†E-mail: [email protected]
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Abstract

Seasonal reproduction patterns are typically observed in small ruminants and are a major limitation for production efficiency in most meat- and dairy-type production systems. Indeed, selection for reduced seasonality could be an appealing strategy for the small ruminant industry worldwide, although its genetic background has been poorly analyzed. One of the main limitations relied on the availability of appropriate analytical tools to cope with the circular (i.e. year-round) pattern of lambing and kidding data. The recent development of a heteroskedastic circular mixed model provided the statistical tool to go deeply into the knowledge of seasonality in small ruminants. In this study, 26 005 lambing distribution records from 4764 Ripollesa ewes collected in 20 purebred flocks were analyzed. The model accounted for systematic (lambing interval and ewe age), permanent environmental (flock-year-season and ewe) and additive genetic sources of variation influencing both mean and dispersion pattern (i.e. heteroskedasticity). Systematic effects suggested that first-lambing ewes and short lambing intervals delayed lambing date (~30 days) and increased dispersion of the lambing period. Nevertheless, this was partially compensated by ewe age, given that youngest females tended to concentrate the lambing peak. Flock-year-season, permanent ewe and additive genetic sources of variation reached moderate variance components for direct (and residual) effects on lambing distribution, they being 0.119 (0.156), 0.092 (0.132) and 0.195 (0.170) radians2, respectively. Moreover, all 95% credibility intervals were placed far from the null estimate. Covariances between direct and residual effects where high and positive for additive genetic (posterior mean, 0.814) and permanent ewe effects (posterior mean, 0.917), whereas it was not relevant for flock-year-season. Selection for direct additive genetic effects should be able to advance or delay the lambing peak, whereas selection applied on residual additive genetic effects should increase or reduce seasonality (i.e. concentrate or flatten the lambing peak). Moreover, the positive and relevant genetic covariance between direct and residual effects also suggested correlated genetic responses. As example, genetic selection for earlier lambing peaks must also reduce seasonality, whereas selection for narrower lambing seasons may originate a delay in the lambing peak. These results must be viewed as the first attempt to analyze systematic, environmental and genetic sources of variation of lambing distribution within the circular paradigm, they providing a reliable characterization of these effects within the context of an heteroskedastic model.

Keywords

canalizationcircular modelRipollesaseasonalityvariance component
Type
Research Article
Information
animal , Volume 13 , Issue 10 , October 2019 , pp. 2140 - 2145
Copyright
© The Animal Consortium 2019 

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References

Al-Shorepy, SR and Notter, DR 1997. Response to selection for fertility in a fall-lambing sheep flock. Journal of Animal Science 75, 2033–2040.CrossRefGoogle Scholar
Bon, R, Dardaillon, M and Estevez, I 1993. Mating and lambing periods as related to age of female mouflon. Journal of Mammalogy 74, 752–757.CrossRefGoogle Scholar
Breitenberger, E 1963. Analogues of the normal distribution on the circle and the sphere. Biometrika 50, 81–88.CrossRefGoogle Scholar
Casellas, J, Martín de Hijas-Villalba, M and Id-Lahoucine, S 2019. Analysis of lambing distribution in the Ripollesa breed. I. Development and comparison of circular von Mises models. Animal, published online https://doi.org/10.1017/S1751731119000363.CrossRefGoogle Scholar
Chemineau, P, Bodin, L, Migaud, M, Thiéry, JC and Malpaux, B 2010. Neuroendocrine and genetic control of seasonal reproduction in sheep and goats. Reproduction in Domestic Animals 45, 42–49.CrossRefGoogle ScholarPubMed
Chemineau, P, Malpaux, B, Brillard, JP and Fostier, A 2007. Seasonality of reproduction and production in farm fishes, birds and mammals. Animal 1, 419–423.CrossRefGoogle ScholarPubMed
Esquivelzeta, C, Fina, M, Bach, R, Madruga, C, Caja, G, Casellas, J and Piedrafita, J 2011. Morphological analysis and subpopulation characterization of Ripollesa sheep breed. Animal Genetic Resources Information 49, 9–17.CrossRefGoogle Scholar
Fisher, NI 1993. Statistical analysis of circular data. Cambridge University Press, Cambridge, UK.CrossRefGoogle Scholar
Forcada, F, Abecia, JA and Sierra, I 1992. Seasonal changes in estrous activity and ovulation rate in Rasa Aragonesa ewes maintained at two different body condition levels. Small Ruminant Research 8, 313–324.CrossRefGoogle Scholar
Gelfand, A and Smith, AFM 1990. Sampling based approaches to calculating marginal densities. Journal of the American Statistical Association 85, 398–409.CrossRefGoogle Scholar
Ibáñez-Escriche, N, Sorensen, D, Waagepetersen, R and Blasco, A 2008a. Selection for environmental variation: a statistical analysis and power calculations to detect response. Genetics 180, 2209–2226.CrossRefGoogle ScholarPubMed
Ibáñez-Escriche, N, Varona, L, Sorensen, D and Noguera, JL 2008b. A study of heterogeneity of environmental variance for slaughter weight in pigs. Animal 2, 19–26.CrossRefGoogle ScholarPubMed
Metropolis, N, Rosenbluth, AW, Rosenbluth, MN, Teller, AH and Teller, E 1953. Equations of state calculations by fast computing machines. Journal of Chemical Physics 21, 1087–1092.CrossRefGoogle Scholar
Mulder, K and Klugkist, I 2017. Bayesian estimation and hypothesis tests for a circular generalized linear model. Journal of Mathematical Psychology 80, 4–14.CrossRefGoogle Scholar
Notter, DR 2008. Genetic aspects of reproduction in sheep. Reproduction in Domestic Animals 43 (suppl. 2), 122–128.CrossRefGoogle Scholar
Quirke, JF, Hanrhan, JP, Loughnane, W and Triggs, R 1986. Components of the breeding and non-breeding seasons in sheep: breed effects and repeatability. Irish Journal of Agricultural and Food Research 25, 167–172.Google Scholar
Raftery, AE and Lewis, SM 1992. How many iterations in the Gibbs sampler?. In Bayesian statistics IV (ed. Bernardo, JM, Berger, JO, Dawid, AP and Smith, AFM), pp. 763–773. Oxford University Press, Oxford, UK.Google Scholar
Ricordeau, G 1982. Selection for reduced seasonality and post-partum anoestrus. In 2nd World Congress of Genetics Applied to Livestock Production, Madrid, Spain, pp. 338–347.Google Scholar
Ros, M, Sorensen, D, Waagepetersen, R, Dupont-Nivet, M, SanCristobal, M, Bonnet, JC and Mallard, J 2004. Evidence for genetic control of adult weight plasticity in the snail Helix aspersa. Genetics 168, 2089–2097.CrossRefGoogle ScholarPubMed
Rosa, HJD and Bryant, MJ 2003. Seasonality of reproduction in sheep. Small Ruminant Research 48, 155–171.CrossRefGoogle Scholar
SanCristobal-Gaudy, M, Elsen, J-M, Bodin, L and Chevalet, C 1998. Prediction of the response to a selection for canalisation of a continuous trait in animal breeding. Genetics, Selection, Evolution 30, 423–451.CrossRefGoogle Scholar
Teyssier, J, Canepa, S, Chemineau, P, Malpaux, B, Migaud, M and Bodin, L. 2002. Preliminary results on selection lines for spontaneous spring ovulatory activity in merinos d’arles sheep. In 7th World Congress on Genetics Applied to Livestock Production, Montpellier, France, pp. 19–23.Google Scholar
Van Tassell, CP and Van Vleck, LD 1996. Multiple-trait Gibbs sampler for animal models: flexible programs for Bayesian and likelihood-based (co)variance component inference. Journal of Animal Science 74, 2586–2597.CrossRefGoogle ScholarPubMed
Westell, RA, Quaas, RL and Van Vleck, LD 1988. Genetic groups in an animal model. Journal of Dairy Science 71, 1310–1318.CrossRefGoogle Scholar
Wheeler, AG and Land, RB 1977. Seasonal variation in oestrus and ovarian activity of Finnish Landrce, Tasmanian Merino and Scottish Blackface ewes. Animal Production 24, 363–376.Google Scholar
Wright, S 1922. Coefficient of inbreeding and relationship. American Naturalist 51, 636–639.Google Scholar