SciELO - Scientific Electronic Library Online

 
vol.11 número2Efecto de un complejo multienzimático y un probiótico en gallinas de postura alimentadas con dietas sorgo-soya-canolaCalidad seminal de ovinos de pelo suplementados con Moringa oleifera (Moringaceae) y Trichanthera gigantea (Acanthaceae) índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados

Revista

Articulo

Indicadores

Links relacionados

  • No hay artículos similaresSimilares en SciELO

Compartir


Revista mexicana de ciencias pecuarias

versión On-line ISSN 2448-6698versión impresa ISSN 2007-1124

Rev. mex. de cienc. pecuarias vol.11 no.2 Mérida abr./jun. 2020  Epub 23-Oct-2020

https://doi.org/10.22319/rmcp.v11i2.5152 

Articles

Phenotypic and genetic trends for peak yield, milk yield, and lactation persistency in the Murciano-Granadina breed

Judith Carmen Miranda Alejoa  b 

José Manuel León Juradob  e 

Camillo Pieramatic 

Mayra Mercedes Gómez Carpiob  * 

Jesús Valdés Hernándezd 

Cecilio José Barba Capotea 

a Universidad de Córdoba. Departamento de Producción Animal, Campus de Rabanales. Edif. de Producción Animal, Córdoba 14071, España.

b Universidad de Córdoba. Departamento de Genética. Campus de Rabanales. Córdoba, España.

c Università Degli Studi di Perugia. Dipartimento di Medicina Veterinaria. Perugia, Italy.

d Universidad Autónoma de Barcelona. Departamento de Ciencia Animal y de los Alimentos. Centre for Research in Agricultural Genomics, Barcelona, España

e Delegación de Agricultura y Medio Ambiente. Centro Agropecuario Provincial. Diputación de Córdoba, Córdoba. España


Abstract

This study evaluated the genetic (TG) and phenotypic (TF) trends for the peak yield (PP), milk yield (RL), and lactation persistency (P) traits of the Murciano-Granadina (MG) goat lactation curve obtained from 80,872 lactations of 85,404 goats (historical records from 1990-2012). The biomodelling of lactation curves allowed us to estimate the PP, RL, and P traits using the Spline model in the “R” software. The genetic values (VGs) were obtained using the univariate animal model with repeated observations, employing the MTDFREML package. The TG and TF were estimated via the least-squares regression of the average of VGs and known yield information according to the year of birth. While calculating the TG and TF, linear regression coefficients (b) were obtained, where the b values for PP, RL, and P were +0.00071, +0.00698; +0.00114, +0.01117; and +0.00002, -0.00076, respectively. The TG and TF for the PP and RL behaved similarly following an upward trend line with increasing and decreasing intervals. The TG for P showed seasonal variations while the TF followed a downward trend with more consistent points in its trajectory; supporting the idea that high yields are detrimental to the P. These results inform the breeders about the behavior of these traits and provide the basis for the incorporation of the lactation persistency as a selection criteria in the genetic program of the MG breed.

Key words Breeding program; Goat; Milk; Genetic value

Resumen

El objetivo fue evaluar las tendencias genéticas (TG) y fenotípicas (TF) para los caracteres de pico productivo (PP), rendimiento lechero (RL) y persistencia de la lactación (P) en la curva de lactación de la raza Murciano-Granadina (MG). Para ello se utilizaron 180,872 lactaciones, de 85,404 cabras (registros históricos de 1990-2012). Para la obtención de los caracteres de interés (PP, RL y P) se realizó la biomodelación de curvas de lactación mediante el modelo Spline usando el software “R”. Los valores genéticos (VG) se obtuvieron mediante modelo animal univariado con observaciones repetidas, empleándose el paquete MTDFREML. Las TG y TF se estimaron vía mínimos cuadrados en una regresión del promedio de los VG e información productiva conocida según el año de nacimiento. En el cálculo de las TG y TF se obtuvieron coeficientes de regresión lineal (b), donde los valores b para PP, RL y P fueron de +0.00071, +0.00698; +0.00114, +0.01117 y +0.00002, -0.00076; respectivamente. El trayecto de TG, TF de PP y RL se comportó de la misma manera siguiendo una línea de tendencia ascendente con presencia de intervalos de crecimiento y decrecimiento. La TG de P mostró un comportamiento estacional y la TF fue descendente con puntos más consistentes en su recorrido; reforzando la idea de que altas producciones van en detrimento de la P. Estos resultados permiten informar a los criadores del comportamiento de estos caracteres y considerar la incorporación de la persistencia de la lactación como criterio de selección en el programa genético de la raza.

Palabras clave Programa de cría; Cabra; Leche; Valores genéticos

Introduction

Goats are relevant worldwide, especially in developing countries, where they are bred with multifunction criteria1. However, dairy goat breeds are especially important in the southern European livestock, and even though their census is low compared to the total global population, France and Spain have achieved considerable yield increases and more extended lactation periods. This productive efficiency responds to the need to provide large quantities of milk to the high-quality goat-cheese industry, linked to deep-rooted cultural traditions in some European countries, which continue to offer an optimistic perspective for the goat sector2.

The Murciano-Granadina (MG) breed is part of a select group of specialized dairy goats, becoming one of the leading dairy breeds of Spain, both in census (104,000 breeding females included in the Breed Registry) and yields (584.4 kg of milk per lactation)3. This information positions the MG breed in the first order, next to the Florida and Malagueña breeds, due to its high potential yield compared to other native Spanish breeds like the Guadarrama, Majorera, Palmera, Payoya, and Tinerfeña goats.

The MG breed was officially recognized in the seventies, and since then, there are references on the Scheme for the Genetic-Functional Assessment of Reproductive Males (Resolution of March 28, 1979, of the Directorate General for Agricultural Products4. The current animal genealogical and functional records integrate a robust database, which allows breeders to perform genetic evaluations.

The current MG selection program has been consolidated after 29 yr of selection, emphasizing traits like milk yield, fat, protein, and dry extract yield. In this case, the estimation of genetic trends (TG) is important to evaluate the efficacy of the applied breeding schemes and to provide the breeders with information that will allow them to develop more efficient selection programs5.

Also, the evaluation of TG and phenotypic trends (TF) improves the understanding and helps transmit the selection effect compared to previous generations6,7, as well as to contrast the obtained results depending on the proposed scheme, allowing to correct any deviation from the expected.

In reference studies performed in dairy species, researchers have generally focused on the TG and TF for milk yield (RL) and composition traits; however, the genetic behavior of other traits related to the lactation curve has not been reported 8.

Furthermore, this is the first study of the TGs for lactation curve parameters, peak yield (PP) and persistency (P) in particular, in MG goats. This study aims to justify the consolidation of these traits for their inclusion as selection criteria in the MG breeding program. Therefore, this study aimed to evaluate the TG and TF for the PP, RL, and P traits in the Murciano-Granadina (MG) breed.

Material and methods

Data and editing procedures

The genealogy and functional information used in this study belong to the historical archives of the MG goat official breeding program. The original database included 180,872 lactations, adjusted to 210 d (A4 method of ICAR 9), from 85,404 goats from 229 livestock farms, encompassing the birth years of 1990-2012. During the exploratory analysis, the database was edited and standardized to eliminate the data considered anomalous: repeated data, lactations with less than six controls, daily yields exceeding 10 kg of milk or below 0.2 kg, and null values; based on the standardization carried out by the MG goat breeding program.

Genetic analysis and statistical models

The biomodelling of individualized lactation curves allowed to estimate the PP, RL, and P traits using the Spline model for its best fit for the breed, R2, and flexibility10. Also, for the model resolution, it was used the statistical software “R“ version 3.2.311. The P values of lactation are mainly expressed as dimensionless measures12.

The individual values of the traits (PP, RL y P) in the lactation curves were analyzed using an animal model with repeated observations and the univariate option (single trait). The single trait model used is written in matrix notation 13.

y = Xb + Zaa + Zpp + e

Where:

y= is the phenotypic information vector of the analyzed PP, RL, and P traits.

b= vector of the fixed effects (contemporary group of herd-year-season (HYS-unified), lactation number, birth type, and age (covariable)).

a= vector of the additive random effect of the animal.

p= vector of the permanent environmental effect.

e= vector of residual effects for the analyzed traits.

X, Za, and Zp: incidence matrices (known) of fixed effects (X) and random effects (Za and Zp).

The variance components for all the random effects were estimated with the Multiple Trait Derivate Free Restricted Maximum Likelihood (MTDFREML) program14 and adjusting the univariate animal model (described previously). To evaluate the logic estimations, we used a convergence criterium of Var [-2log(L)] < 1x10-9 (where L represents the likelihood function).

The genetic values (VG) for the traits of interest were estimated using the best linear unbiased prediction method (BLUP) 15. To estimate the TG and TF, the estimated VGs were adjusted in a fixed-effects model with the year of birth as the only fixed effect. Alternatively, for the traits of interest, we also estimated the environmental trends (TA) using the predictions from the linear regression coefficients (b) obtained from the average of the VGs expressed by year of birth and known yield information in that year. These procedures were carried out with the statistical program “R”11.

Results

The descriptive statistics for the analyzed traits revealed a typical mean and deviation of 1.05 ± 0.32 and 1.21 ± 0.35 kg of milk for RL and PP, respectively, and 1.03 ± 0.35 for P.

Figures 1-6 show the TG and TF regarding the year of birth for the analyzed traits with their respective linear regression coefficient (b). These results suggest dynamic variations for the MG goat population, detecting a rebound stationary point in 1999, which coincides with the start of the modern selection scheme based on the BLUP evaluations. Subsequently, oscillations around the X-axis for these three traits reveal that for 22 year, the PP and RL traits showed an upward trend behavior and similar magnitudes; meanwhile, the P trait showed a stationary to a downward trend.

Figure 1 Peak yield genetic trend 

Figure 2 Yield genetic trend 

Figure 3 Persistency genetic trait 

Figure 4 Peak yield phenotypic trend 

Figure 5 Yield phenotypic trend 

Figure 6 Persistency phenotypic trend 

The TGs for PP and RL over the analyzed years (1990 to 2012) showed an irregular behavior with increasing and decreasing intervals (Figures 1 and 2) but following an upward trend line with coincident peaks in the years 1992, 1996, 2004, and 2009. For these same traits, the TFs (Figures 4 and 5), also show upward trend lines with regular and consistent fluctuations in the increasing/decreasing intervals (coincident prominent peaks in the years of 1992 and 1998).

The TG for the P trait shows an irregular behavior with increases, decreases, and prominent peaks in the years of 1993, 1995, 2005, 2010, and 2012, unlike the behavior of the other traits that show a stationary trend line (Figure 3).

Particularly, we observed a positive TG for PP and RL and irregular deviations from linearity (Figure 1 and 2). The increase for these treats was significant (P<0.05) with a b of 0.00071 kg/year and 0.00114 kg/year for PP and RL, respectively. Similarly, the TG for P was also positive with prominent peaks (1993, 1995, 2005, 2010, and 2012) and notorious decreases (1992, 1998, 2006 to 2009), showing irregular fluctuation between them with a no-significant increase (P>0.05) and a b of 0.0000219 units/year with a stationary trend line (Figure 3).

Although the TF direction for PP and RL shows an upward trend line, the fluctuations of the increasing/decreasing intervals are also regular and consistent due to the proximity between the points (prominent coincident peaks in 1992 and 1998) and the trend line (Figures 4 and 5). Moreover, the TF for P (Figure 6) decreased when the fluctuations of the increasing and decreasing intervals were regular and consistent in time, with peaks in the years of 1991, 1993, 2002, and 2012.

Consequently, the TFs were positive for PP and RL showing a significant (P<0.05) increase in the TF average for these traits, where b was 0.0069821 kg/year and 0.0111697 kg/year, respectively (Figures 4 and 5). However, although the TF for P was negative with regular fluctuations and a significant (P<0.05) decrease with a b value of -0.0007629 units/year (Figure 6), there is also a slight increase in this trend since the year of 2009, which stabilizes during 2010, with an increase in 2011. The TA analysis for P suggests a negative influence, although not significant (P>0.05 with b of -0.00000293 units/year).

Discussion

The TGs monitor and evaluate the selection program efficiency16. The TG evaluation of dairy traits indicates the direction of the breed selection vector, as well as the rate of genetic improvement due to the application of the breeding program17. It is also essential to provide information to the breeders for them to develop more efficient selection programs5.

In this study, the direct estimation of the TG indicated that there was a significant and positive genetic improvement in all the studied traits, except for the P trait, which indicates that selection was effective, both in the period based in bulk selection (1990-1999) and in familiar information (1999-2012). Therefore, this information could be useful to evaluate previous efforts for the improvement and preservation of the genetic potential of these traits and to determine the future strategies and work in the population of MG goats.

It is important to consider that this is the first study in which the PP, RL, and P traits are evaluated as a group, RL being a trait routinely used for breed selection, while PP and P are candidate traits for possible inclusion in the selection scheme. Our results show that, in the 22 analyzed years, the PP and RL traits showed a similar and upward trend behavior, while the P trait showed a stationary to a downward trend, which supports the idea that high yields are detrimental to the P.

The results show that both the TG and TF for the three traits (PP, RL, and P) have an irregular behavior with fluctuating increasing and decreasing intervals, most noticeable in the years before 1999; until that year, the selection was based on the phenotype (bulk selection). However, since 1999, when the annual mean VG trends for the PP and RL traits present a more constant-positive evolution, consistent with the year when the work guidelines for the selection scheme of dairy goat stallions of the MG breed were established4, based on family information and BLUP estimations, according to the guidelines published in the Resolution of May 12, 1999, of the Ministry of Agriculture, Fisheries, and Food.

Additionally, the reference points of the mean VGs are closer to the trend line, with prominent peaks in the years of 2004 and 2009, and noticeable decreases in the years of 2005, 2006, 2011, and 2012; according to MURCIGRAN 4, they could be related to the incorporation of animals to the selection schemes from livestock farms outside the selective nucleus in the mentioned years.

The TGs for PP and RL are parallel, prominent peaks are observed in years before 1999; the most noticeable decrease occurred in 2012. In this regard, in December 2011 it was officially agreed to merge the associations of CAPRIGRAN and ACRIMUR in MURCIGRAN4, leading to the management of a single Breed Book, and therefore the data and records thereof, which would justify the noticeable decreases between 2011 and 2012 in both the TG and TF.

Even though the TG for P has prominent peaks (1993, 1995, 2005, 2010, and 2012) and notorious decreases (1992, 1998, 2006 to 2009) in addition to alternating and irregular between them (sic), it shows a positive seasonal trend line. Meanwhile, the TF is a discrete decreasing trend line with less prominent peaks in the years 1991, 1993, 2002, and 2012.

This information supports the idea of paying attention to the P trait and its group behavior with others because of its direct impact on the lactation curves. Lengthening the P would allow for flattening the declining part of the lactation curve, or at least mitigate the crucial peaks that affect the immune system (the antagonistic relationship between milk production and disease resistance traits) promoting a more efficient lactation with considerable benefits, such as avoiding animal health risks and associated costs18,19.

In this regard, specific studies in dairy goats conclude that animal selection using P as a criterium and linked to the peak yield value is possible without changing the amount of total milk20, and therefore genetically modify the lactation curve19. Thus, early estimation of P in lactations in progress can represent a useful tool for both the breeding and management strategies21, especially in the implementation of strategies to reduce the production of greenhouse gases derived from the fight for climate change mitigation22.

The TG estimations evaluate the results of the program and inform the breeders about the selection decisions made, allowing the necessary adjustments to optimize the genetic progress of each population23; therefore, the results of this evaluation allow to propose the incorporation on the P trait to the breeding program.

Finally, in general, the phenotypes and the breeding values for the PP and RL traits increased in the period of study; however, although the P trait was genetically stationary, its TF was decreasing, probably due to environmental factors, such as the change of management. Studies referred to in this regard indicate that the environment does not directly modify the genetic constitution of the individual. However, it does determine the extent of its expression and the genetic potential of animals, which will express to the extent that environmental conditions allow24.

Conclusions and implications

The global analysis of the TG and TF for the analyzed traits demonstrated irregular dynamic variations with increasing and decreasing intervals, as well as peaks in determined points throughout the study. The genetic and phenotypic behaviors of these three traits indicate that, in 22 years, the PP and RL traits showed a similar upward trend and magnitude, while the P trait was stationary to decreasing. The latter supports the idea that high yields are detrimental to the P. In all cases, important events in the breeding program, like the federation of associations or the introduction of family selections, left their mark on trends. These findings will allow to inform breeders about the behavior of these traits and consider incorporating the P in the selection scheme.

Acknowledgements and conflict of interests

Authors thank the Spanish Federation of Goat Breeders, Murciano-Granadina (MURCIGRAN) breed. A special thanks to MsC. Bolívar Samuel Sosa Madrid for his valuable contributions to the manuscript. There is no conflict of interest.

REFERENCES

1. Adewumi OO, Oluwatosin BO, Tona GO, Williams TJ, Olajide OO. Milk yield and milk composition of Kalahari Red goat and the performance of their kids in the humid zone. Arch Zootec 2017; 66:587-592. [ Links ]

2. FAO. Producción y productos lácteos: pequeños rumiantes. 2018. http://www.fao.org/agriculture/dairy-gateway/produccion/pequenos-rumiantes/#3 . Consultada: 25 Feb, 2018. [ Links ]

3. Delgado JV, Landi V, Barba CJ, Fernández J, Gómez MM, Camacho ME, et al. Murciano-Granadina Goat: A Spanish local breed ready for the challenges of the twenty-first century. Simões J, Gutiérrez C. editors. In: Sustainable goat production in adverse environments: Volume II. Springer International Publishing; 2017:205-219. [ Links ]

4. MURCIGRAN. Federación Española de Criadores de Caprino de Raza Murciano- Granadina. La raza Murciano-Granadina - Historia. http://www.murcigran.es/la-raza-murciano-granadina/3-historia . Consultada 5 Abr, 2017. [ Links ]

5. Khojastehkey M, Aslaminejad AA. Study of the environmental, genetic and phenotypic trends for pelt traits and body weight traits in Zandi sheep. J Appl Anim Res 2013;41:356-361. [ Links ]

6. Kuthu ZH, Javed K, Babar ME, Sattar A, Abdullah M. Estimation of genetic parameters for pre-weaning growth traits in Teddy goats. J Anim Plant Sci 2017;27:1408-1414. [ Links ]

7. Filho KE, Silva L, Alves R, Figuereido GR. Tendência genética na raça Gir. Pesqui Agropecu Bras 2000;35:787-791. [ Links ]

8. Abdallah JM, McDaniel BT. Genetic parameters and trends of milk, fat, days open, and body weight after calving in North Carolina Experimental herds. J Dairy Sci 2000;83:1364-1370. [ Links ]

9. ICAR. International Committee for Animal Recording Rome, Italy;1990. http://www.icar.org/Links ]

10. León JM, Macciotta NPP, Gama LT, Barba C, Delgado JV. Characterization of the lactation curve in Murciano-Granadina dairy goats. Small Ruminant Res 2012;107:76-84. [ Links ]

11. R Core Team. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. R-project; 2014. https://www.r-project.org/. [ Links ]

12. Macciotta NPP, Dimauro C, Steri R, Cappio-Borlino A. Mathematical modelling of goat lactation curves. In: Antonello Cannas G, Pulina A, editors. Dairy goats feeding and nutrition. Sassari: CAB International; 2008:31-46. [ Links ]

13. Mrode RA. Linear models for the prediction of animal breeding values. 3th ed. Hulbert S, Povey L, editors. Malta; 2014. [ Links ]

14. Boldman KG, Kriese LA, Van Vleck LD, Van Tassel CP, Kachman SD. A manual for use of MTDFREML. A set of programs to obtain estimates of variances and covariances (DRAFT). Lincoln, NE: USDA. ARS. 1995. [ Links ]

15. Henderson CR. A simple method for computing the inverse of a numerator Relationship matrix used in prediction of breeding values. Biometrics 1976;32:69-83. [ Links ]

16. Montaldo H, Almanza A, Juárez A. Genetic group, age and season effects on lactation curve shape in goats. Small Ruminant Res 1997; 24:195-202. [ Links ]

17. Bosso NA, Cissé MF, van der Waaij EH, Fall A, van Arendonk JAM. Genetic and phenotypic parameters of body weight in West African Dwarf goat and Djallonké sheep. Small Ruminant Res 2007; 67:271-278. [ Links ]

18. Capuco AV, Ellis SE, Hale SA, Long E, Erdman RA, Zhao X and Paape MJ. Lactation persistency: insights from mammary cell proliferation studies. J Anim Sci 2003;81 Suppl 3:1831. [ Links ]

19. Jakobsen JH. Genetic correlations between the shape of the lactation curve and disease resistance in dairy cattle [Doctoral tesis]. Copenhague, Denmark: The Royal Veterinary and Agricultural University; 2000 http://www.forskningsdatabasen.dk/ en/catalog/ [ Links ]

20. Pala A, Savas T. Persistency within and between lactations in morning, evening and daily test day milk in dairy goats. Arch Anim Breed 2005;48:396-403. [ Links ]

21. Macciotta NPP, Dimauro C, Rassu SPG, Steri R, Pulina G. The mathematical description of lactation curves in dairy cattle. Ital J Anim Sci 2011;10(4): e51. [ Links ]

22. Broucek J. Methane abatement strategies based on genetics and dietary manipulation of rumiants: a review. Arch Zootec 2018;67:448-458. [ Links ]

23. Torres-Vázquez JA, Valencia M, Castillo H, Montaldo HH. Tendencias genéticas y fenotípicas para características de producción y composición de la leche en cabras Saanen de México. Rev Mex Cienc Pecu 2010;1:337-348. [ Links ]

24. Cerón-Muñoz MF, Tonhati1 H, Costa C, Benavides F. Genotype and environment interaction in Colombian Holstein cattle. Arch Latinoam Prod Anim 2001;9:72-78. [ Links ]

Received: November 19, 2018; Accepted: March 19, 2019

Creative Commons License Este es un artículo publicado en acceso abierto bajo una licencia Creative Commons