Genetic parameters of forage dry matter intake and milk produced from forage in Swedish Red and Holstein dairy cows

Abstract

High-yielding dairy cows are often fed high proportions of cereal grain and pulses. For several reasons, it would be desirable to replace these feed sources with forage, which is not suitable for human consumption. Feeding large amounts of forage to dairy cows could also make dairy production more publicly acceptable in the future. In this study, we estimated genetic parameters for total dry matter intake (DMI), DMI from forage (DMI For), energy-corrected milk (ECM), and ECM produced from forage (ECM For). A total of 1,177 lactations from 575 cows of Swedish Red (SR) and Holstein (HOL) dairy breeds were included in the study. Mixed linear animal random regression models were used, with fixed effect of calving season and lactation week nested within parity 1 and 2+, fixed effect of calving year, and random regression coefficients for breeding value (up to linear) and permanent environmental effect (up to quadratic) of the cow. Heritability for DMI and DMI For was generally higher for HOL than for SR in all-parity data and in later parities; however, the opposite was true for first parity. Heritability for DMI and DMI For during the first 8 wk averaged 0.11 and 0.15, respectively, in all-parity data for the 2 breeds. Corresponding values for ECM For and ECM were 0.21 and 0.29, respectively. In first parity, values were 0.32, 0.36, 0.28, and 0.51, respectively. The genetic correlation between DMI and DMI For was high, above 0.83, and fairly constant across the lactation. The genetic correlation between ECM For and ECM was close to unity in the later part of lactation for both breeds, but was around 0.8 in the early lactation for both breeds; it decreased for HOL to 0.54 in wk 17. The genetic correlations between DMI and ECM For and between DMI For and ECM For were low and negative for HOL (absolute value ~0.2-0.3), but changed for SR from weakly positive in early lactation to negative values and back to positive toward the end of lactation. For most traits, the correlation between wk 1 and wk 8 into the lactation was very high; the lowest value was for DMI in HOL at 0.81. The genetic correlation between parities was rather high in the first part of the lactation. During the first 8 wk, the correlation was lower for HOL than for SR, except for ECM. We found that DMI For and ECM For showed reasonably large heritability, and future work should explore the possibility of genomic evaluations.

Breeding goal traits accounting for feed intake capacity and roughage or concentrate intake separately

“…Furthermore the genetic correlation between DMI and DMIR was 0.96, suggesting that roughage intake explained nearly all of the genetic variation in total feed intake in our data. These results agree with the results of a Swedish study, which found that the genetic correlation between forage intake and total intake was above 0.90 for Holstein and 0.83 for Swedish Red during the lactation period (Tarekegn et al, 2021). Obviously, this genetic correlation always depends on concentrate feeding system.…”

“…The study presented here addresses the same question about concentrate versus roughage efficiency but from a different viewpoint. Rather than investigating G×E for total DMI, the objective here was to use existing data, which is used in the national genetic evaluations for DMI, to define alternative traits related to feed intake capacity and roughage or concentrate intake separately and quantify their phenotypic and genetic parameters, an approach that was also used by Tarekegn et al (2021). Insight on these novel traits might help to judge whether it is worthwhile to separate these traits in the genetic evaluation, to breed for intake capacity or to breed for concentrate-or roughage-efficient cows separately.…”

Genetic parameter estimates for daily predicted gross feed efficiency and its association with energy-corrected milk in South African Holstein cattle

“…Spurlock et al ( 2012 ) also observed similar means for actual GFE of primiparous and multiparous American Holstein cows. The overall mean for daily pGFE across lactations was lower compared to values reported recently for actual GFE in Austrian, German and Swedish Holstein cattle (Köck et al 2018 ; Tarekegn et al 2021 ; Becker et al 2022 ). Cows in the present study also produced relatively lower daily ECM on average than Austrian, German and Swedish Holstein cattle (Köck et al 2018 ; Tarekegn et al 2021 ; Becker et al 2022 ).…”

“…Energy-corrected milk is a major predictor trait for GFE, and is also of great economic importance. Besides genetic variation between populations, differences in measurement or prediction methods may account for discrepancies in mean GFE among studies (Köck et al 2018 ; Tarekegn et al 2021 ; Becker et al 2022 ). On the other hand, mean ECM is based on yield of milk, which is invariably measured directly, using standard measuring devices (Kirchgeßner 1997 ).…”

Ensuring the stability of milk production based on an individual approach to feeding lactating cows

“…And the point is not in the norms of feeding, as such, or the genetic capabilities of animals, but in the need for livestock breeding in completely new conditions, the organization of a well-thought-out differentiated approach to feeding, taking into account irreplaceable nutritional factors, an assessment of the total nutritional value of feed by exchangy energy and the use of balancing additives in the structure diet [4,[6][7]. The modern science of animal feeding has been enriched with new data on the physiological mechanisms of regulation of biosynthesis in the body, on metabolism and energy, biochemical composition and properties of feed [8][9][10][11][12]. All this makes it possible not only to meet the physiological needs of animals for nutrients, but also to increase the level of transformation of feed nutrients into livestock products, ensuring an increase of productivity and effective use of feed [13][14][15].…”