Genetic correlations among selected traits in Canadian Holsteins

Abstract

In the Canadian dairy industry, there are currently over 80 traits routinely evaluated, and more are considered for potential selection. Particularly, in the last few years, recording has commenced for several new phenotypes required to introduce novel traits with high economic importance into the selection program. However, without a systematic estimation of the genetic correlations that exist among traits, the potential results of indirect selection are unknown. Therefore, 29 traits representative of the trait diversity for first lactation Canadian animals were selected. Their two-by-two genetic correlations were estimated from a dataset of 62 498 first lactation Holstein cows, using a Markov Chain Monte Carlo Gibbs sampling approach. The general tendencies among the groups of traits confirm that production traits are negatively correlated with fertility traits and that functional traits are positively correlated with one another. The association of udder depth with fertility and disease resistance has also been highlighted. This contribution offers a comprehensive overview of current estimates across traits and includes correlations with novel traits that constitute an original addition to the literature. These new estimates can be used for newly developed genomic evaluation models and possibly lead to more accurate estimations of the dairy cows’ overall genetic merit.

Estimated genetic parameters for all genetically evaluated traits in Canadian Holsteins

“…Cai et al (2020) also reported high genetic correlations between MY and PY (0.78), FY and MY (0.40), and FY and PY (0.56). Likewise, Kadarmideen et al (2003) and Martin et al (2019) reported similar results as in this study.…”

“…Genetic parameters related to the Canadian Holstein population have been estimated for production (e.g., Miglior et al, 2007;Loker et al, 2012), conformation (e.g., Van Dorp et al, 2004), fertility (e.g., Jamrozik et al, 2005;Sewalem et al, 2010, Alves et al, 2020, and relatively more novel traits, such as metabolic diseases (e.g., Guarini et al, 2019), hoof health (e.g., Malchiodi et al, 2017) and milk properties (e.g., Nayeri et al, 2020). Martin et al (2019) looked at the genetic correlation among a subset of 28 traits on Canadian Holstein cows from all trait groups, except hoof health. In addition to the importance of re-estimating these parameters using current data, a study involving all current routinely recorded Estimated genetic parameters for all genetically evaluated traits in Canadian Holsteins G. A. Oliveira Junior, 1 * F. S. Schenkel, 1 L. Alcantara, 1 K. Houlahan, 1 C. Lynch, 1 and C. F. Baes 1,2 traits in Canada has not yet been done.…”

Estudio de las correlaciones entre valores genéticos producción – reproducción y tipo lineal de los toros Holstein en Ecuador

“…Las correlaciones entre los rasgos de producción, reproductivos y de tipo lineal de la presente investigación, son análogos a los realizados en vacas Holstein canadienses, estimaciones para F% y P% con rasgos de tipo lineal fueron inferiores a 0,20; que van desde 0,15 (Profundidad de la ubre (UD) con P%) a -0,03 (FL con P%), siendo las correlaciones entre el contenido de leche y UD y MS significativas; además no se reportó correlación entre los rendimientos de producción y FL, y las correlaciones favorables entre los rendimientos de producción con DS y MS (Martin et al, 2019). La literatura también menciona valores similares a otros estudios en Holstein Iraníes (Mokhtari et al, 2015); Holstein de Uruguay (Frioni et al, 2017).…”

“…Estos resultados confirman aún más la importancia de considerar las correlaciones genéticas al seleccionar múltiples rasgos. Por lo que (Kadarmideen et al, 2000), definieron estas correlaciones cómo la superioridad genética para un rasgo que tiende a heredarse con superioridad o inferioridad genética para otro rasgo (Martin et al, 2019). La causa de una correlación genética se puede encontrar a nivel genómico, debido a la vinculación o pleiotropía entre las regiones que influyen en los rasgos considerados (Rauw et al, 1998).…”

Autoregressive model for genetic evaluation of longitudinal reproductive traits in Brazilian Holstein cattle

“…Over the years, milk production traits have received the major attention in the selection objectives of dairy cattle breeding programs. However, the intensive genetic selection to increase production, negatively affected the reproductive performance of Holstein herds, an indirect response due to unfavourable genetic correlations between these two classes of traits (Martin et al., 2019; Rocha et al., 2018; Rodríguez‐Bermúdez et al, 2019). In this context, the decline of cow fertility has become one of the major challenge in the modern dairy farming due to extra costs with inseminations, reproductive biotechnologies and losses attributed to reproductive disorders and involuntary culling of cows (Chiumia et al., 2013; de Vries & Marcondes, 2020; Mee, 2012; Tiezzi et al., 2012).…”