Statistical modeling of the latent variable of milk production performance in the Murciano-Granadina goats by confirmatory factor analysis

Document Type : Research Article (Regular Paper)

Authors

1 Department of Animal Science, Faculty of Agriculture, University of Jiroft, Jiroft, Iran

2 Animal Science Research Department, Kerman Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education & Extension Organization (AREEO), Kerman, Iran

Abstract

In the present study, 15,108 daily records of milk yield (DMY), milk fat percentage (DFP), milk protein percentage (DPP), and milk somatic cell score (DSCS) in the first two lactation periods of the Murciana-Granadina goats, collected from 2017 to 2024 in the southern part of Kerman province of Iran, were used. By applying latent variable modeling technique and confirmatory factor analysis a latent variable of daily milk production performance (DMP) in the first two lactation periods of the Murciano-Granadina goat breed was constructed and evaluated statistically by four goodness of fit measures including standardized root mean square residual (SRMR), root mean square error of approximation (RMSEA), Tucker-Lewis Index (TLI), and comparative fit index (CFI). The values of CFI, TLI, RMSEA, and SRMR, were 0.97, 0.92, 0.05, and 0.02, respectively, implying the suitability of the confirmatory factor model proposed for DMP latent variable in the present study. Standardized factor loadings of the traits used for describing DMP were statistically significant (P < 0.01) values of 0.24, -0.55, -0.54, and -0.37 for DMY, DFP, DPP, and DSCS, respectively. Therefore, it may be concluded that increase in milk yield would increase DMP. On the other hand, increases in milk fat percentage, milk protein percentage, and milk somatic cell score would decrease DMP. For constructing the latent variable of DMP in the Murciano-Granadina goats, emphasis should be on increasing milk quantity and decreasing milk composition traits including milk fat percentage, milk protein percentage, and milk somatic cell score. Pearson’s correlations among the investigated measurable traits were statistically significant (P<0.01), ranging from -0.14 (DMY-DFP and DMY-DSCS) to 0.30 (DFP-DPP). Pearson’s correlations between the DMP latent variable and the measurable milk yield and composition traits were also statistically significant (P<0.01) and were -0.76 (DFP-DMP), -0.75 (DPP-DMP), -0.52 (DSCS-DMP), and 0.33 (DMY-DMP). Overall, the study provides a statistical framework for describing DMP in contexts such as phenotypic evaluations, where a latent construct can capture the concept of milk yield and composition traits more effectively than individual traits alone.

Keywords

Main Subjects


Bentler, P.M., 1990. Comparative fit indexes in structural models. Psychological Bulletin 107, 238-246.
Cecchinato, A., Masciotra, N.P.P., Mele, M., Tagliapietra, F., Schiavon, S., Bittante, G., Pegolo, S., 2019. Genetic and genomic analyses of latent variables related to the milk fatty acid profile, milk composition, and udder health in dairy cattle. Journal of Dairy Science 102, 5254-5265.
Gianola, D., Sorensen, D., 2004. Quantitative genetic models for describing simultaneous and recursive relationships between phenotypes. Genetics 167, 1407-1424.
Godden, S.M., Lissemore, K.D., Kelton, D.F., Leslie, K.E., Walton, J.S., Lumsden, J.H., 2001. Relationships between milk urea concentrations and nutritional management, production, and economic values in Ontario dairy herds. Journal of Dairy Science 84, 1128-1139.
Leal-Gutierrez, J.D., Rezende, F.M., Elzo, M.A., Johnson, D., Penagaricano, F., Mateescu, R.G., 2018. Structural equation modeling and whole-genome scans uncover chromosome regions and enriched pathways for carcass and meat quality in beef. Frontiers in Genetics, 9, 1-13.
Li, H., Mokhtari, M., Tian, J., Sun, G., Esmailizadeh, A., Zhao, M., Wang, X., Jin, L., Chen, L., Zhang, J., Tian, R., 2026. Modelling and genetic analysis of the latent variable of lactation performance in Chinese Holstein dairy cows. Journal of Dairy Research, 93 35- 41.
Lynch, M., Walsh, B., 1998. Genetics and Analysis of Quantitative Traits. Oxford University Press, Sunderland, MA: Sinauer Associates, Inc.
Martinez, A.M., Vega-Pla, J.L., Leon, J.M., Camacho, M.E., Delgado, J.V., Ribeiro, M.N., 2010. Is the Murciano-Granadina a single goat breed? A molecular genetics approach. Arquivo Brasileiro de Medicina Veterinária e Zootecnia 62, 1191-1198.
Menendez-Buxadera, A., Molina, A., Arrebola, F., Gil, M.J., Serradilla. J.M., 2010. Random regression analysis of milk yield and milk composition in the first and second lactations of Murciano Granadina goats. Journal of Dairy Science, 93 2718-2726.
Momen, M., Bhatta, M., Hussain, W., Yu, H., Morota, G., 2021. Modeling multiple phenotypes in wheat using data-driven genomic exploratory factor analysis and Bayesian network learning. Plant Direct 5, e00304.
Oliveira, R. R., Brasil, L. H. A., Delgado, J.V., Peguezuelos, J., León, J.M., Guedes, D. G. P., Arandas, J.K.G., Ribeiro, M.N., 2016. Genetic diversity and population structure of the Spanish Murciano-Granadina goat breed according to pedigree data. Small Ruminant Research 144,170-175.
Penagaricano, F., Valente, B. D., Steibel, J. P., Bates, R. O., Ernst, C. W., Khatib, H., Rosa, G. J. M., 2015. Searching for causal networks involving latent variables in complex traits: Application to growth, carcass, and meat quality traits in pigs. Journal of Animal Science 93, 4617-4623.
R Development Core Team, 2025. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria.
Rosseel, Y., 2012. lavaan: An R package for structural equation modeling. Journal of Statistical Software 48, 1-36.
SAS (Statistical Analysis System), 2010. SAS User’s Guide, Version 9.4. SAS Institute Inc. Cary, North Carolina, USA.
Schumacker, E.R., Lomax, G.R., 1996. A Beginner’s Guide to Structural Equation Modeling. Erlbaum, Mahwah, NJ.
Silva, H.T., Paiva, J.T., Botelho, M.E., Carrara, E.R., Lopes, P.S., Silva, F.F., Veroneze, R., Sterman Ferraz, J.B., Eler, J.P., Mattos, E.C., Gaya, L.G., 2021. Searching for causal relationships among latent variables concerning performance, carcass, and meat quality traits in broilers. Journal of Animal Breeding and Genetics 139, 181-192.
Steiger, J. H., 1990. Structural model evaluation and modification: An interval estimation approach. Multivariate Behavioral Research 25, 173-180.
Valencia-Posadas, M., Lechuga-Arana, A.A., Avila-Ramos, F., Shepard, L., Montaldo, H.H., 2022. Genetic parameters for somatic cell score, milk yield and type traits in Nigerian Dwarf goats. Animal Bioscience 35, 377-384.
Wright, S., 1921. Correlation and causation. Journal of Agricultural Research 20, 557-585.
Yu, H., Campbell, M.T., Zhang, Q., Walia, H., Morota, G., 2019. Genomic Bayesian confirmatory factor analysis and Bayesian network to characterize a wide spectrum of rice phenotypes. Genes, Genomes Genetics 9, 1975-1986.