Genetic parameters of blood β-hydroxybutyrate predicted from milk infrared spectra and clinical ketosis, and their associations with milk production traits in Norwegian Red cows

Abstract

The aim of this study was to estimate genetic parameters for blood β-hydroxybutyrate (BHB) predicted from milk spectra and for clinical ketosis (KET), and to examine genetic association of blood BHB with KET and milk production traits (milk, fat, protein, and lactose yields, and milk fat, protein, and lactose contents). Data on milk traits, KET, and milk spectra were obtained from the Norwegian Dairy Herd Recording System with legal permission from TINE SA (Ås, Norway), the Norwegian Dairy Association that manages the central database. Data recorded up to 120 d after calving were considered. Blood BHB was predicted from milk spectra using a calibration model developed based on milk spectra and blood BHB measured in Polish dairy cows. The predicted blood BHB was grouped based on days in milk into 4 groups and each group was considered as a trait. The milk components for testday milk samples were obtained by Fourier transform mid-infrared spectrometer with previously developed calibration equations from Foss (Hillerød, Denmark). Veterinarian-recorded KET data within 15 d before calving to 120 d after calving were used. Data were analyzed using univariate or bivariate linear animal models. Heritability estimates for predicted blood BHB at different stages of lactation were moderate, ranging from 0.250 to 0.365. Heritability estimate for KET from univariate analysis was 0.078, and the corresponding average estimate from bivariate analysis with BHB or milk production traits was 0.002. Genetic correlations between BHB traits were higher for adjacent lactation intervals and decreased as intervals were further apart. Predicted blood BHB at first test day was moderately genetically correlated with KET (0.469) and milk traits (ranged from −0.367 with protein content to 0.277 with milk yield), except for milk fat content from across lactation stages that had near zero genetic correlation with BHB (0.033). These genetic correlations indicate that a lower BHB is genetically associated with higher milk protein and lactose contents, but with lower yields of milk, fat, protein, and lactose, and with lower frequency of KET. Estimates of genetic correlation of KET with milk production traits were from −0.333 (with protein content) to 0.178 (with milk yield). Blood BHB can routinely be predicted from milk spectra analyzed from test-day milk samples, and thereby provides a practical alternative for selecting cows with lower susceptibility to ketosis, even though the correlations are moderate.

Genetic variation in serum protein pattern and blood β-hydroxybutyrate and their relationships with udder health traits, protein profile, and cheese-making properties in Holstein cows

“…The mean of the marginal posterior distribution of estimates suggests a small additive genetic influence on serum albumin concentrations, whereas total proteins, globulins, and the A:G exhibited moderate heritability (~0.20), in line with other studies that have revealed the existence of genetic variation for blood constituents (e.g., albumin, globulin fractions, total protein; Rowlands et al, 1974;Jensen and Christensen, 1975;Peterson et al, 1982). Blood BHB was instead found to have relatively high heritability (0.37), although it was in the range of published values (Oikonomou et al, 2008;van der Drift et al, 2012b;Belay et al, 2017b). This result indicates that it may be possible to select cows with lower blood BHB, although, considering the nature of the trait, it is clear that more accurate estimates might be obtained by focusing on early lactation.…”

“…Estimates of the additive genetic correlations for BHB and udder health traits, milk production traits, and milk coagulation properties are presented in Table 4. A positive genetic correlation was found between BHB and milk yield (0.716), even if higher than previous findings (Belay et al, 2017b). This was expected because selection for high milk production has resulted in an increased risk of NEB and greater body fat mobilization (Veerkamp et al, 2003;Coffey et al, 2004).…”

“…Genetic analyses have revealed the existence of exploitable genetic variations in bovine blood composition. Additive genetic relationships between blood serum metabolites and milk production traits (e.g., fat and protein) have also been explored (Peterson et al, 1982;Belay et al, 2017b).…”

Metabolic profiling of early-lactation dairy cows using milk mid-infrared spectra

“…These predictions may, however, be considered accurate enough to employ in genomic evaluations, as described by Bastin et al (2016) and Bonfatti et al (2017). The accuracy of our MIR prediction of serum BHB was better than that of Belay et al (2017b), who used MIR predictions of serum BHB to investigate the genetic parameters of ketosis and the genetic relationships between serum BHB concentration and milk production traits. Similarly, our MIR prediction of serum fatty acids concentration had comparable accuracy to the MIR prediction of energy balance reported by McParland et al (2015), who found favorable correlations between MIR-predicted and measured energy balance.…”

A landscape of the heritability of Fourier-transform infrared spectral wavelengths of milk samples by parity and lactation stage in Holstein cows

“…Most research and industry applications using milk FTIR data focus on developing prediction equations for economically important phenotypes such as fine milk composition (Rutten et al, 2010(Rutten et al, , 2011Fleming et al, 2017aFleming et al, ,b, 2018 and technological properties of milk (Cecchinato et al, 2009. In addition, FTIR data have been shown to be a potentially valuable tool for predicting health and reproductive phenotypes (Heuer et al, 2001;Belay et al, 2017;Toledo-Alvarado et al, 2018) and for predicting residual feed intake, DMI, and methane emissions (Shetty et al, 2017a,b;Bittante and Cipolat-Gotet, 2018;Dórea et al, 2018).…”