Disease & heat resistance

Genetics of calf resilience indicators derived from automated milk feeder data and their genetic relationship with respiratory and enteric diseases in American Holstein cattle

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Abstract

Bovine respiratory disease (BRD) and neonatal calf diarrhea (NCD) are major health challenges in the dairy cattle industry, affecting calf welfare and farm profitability. Many dairy farms worldwide are adopting group housing systems with automated milk feeders (AMF), which improve management efficiency but also increase the risk of disease transmission. Therefore, breeding dairy calves that are more resilient to infectious diseases and other stressors is of great importance to the dairy industry. Accordingly, this study derived AMF-based calf resilience indicators and estimated their genetic parameters and relationships with calf health traits. The dataset consisted of daily feeding records collected by Forester Technik AMF systems from 20,241 U.S. Holstein calves born between 2015 and 2024 (15,946 genotyped). After receiving colostrum, calves were placed into group pens until weaning. Resilience indicators were derived from daily milk consumption (DMC) and drinking speed (DS) using a centered 5-day moving median window to define an expected trajectory; daily deviations (observed − expected) were summarized as the natural log of deviation variance for DS (LNDS) and DMC (LNMC) and as deviation skewness for DS (SKDS). Because absolute DMC deviations scaled with intake level, a scale-adjusted indicator based on relative deviations was also computed (LRMC). Robustness of the window choice was assessed using 3- and 7-day moving median windows. Health traits included BRD incidence (INBR; 0/1), number of BRD treatments (NBRD), number of NCD treatments (NNCD), and age at first BRD treatment (AFBR). Single and two-trait animal models were fitted with contemporary group (barn-year-season of birth) and dam parity as categorical fixed effects and mean daily milk entitlement, mean pen density, and number of feeding days as covariates (BW used only contemporary group and parity). The phenotypic mean (± SD) of the resilience indicators, LNDS, SKDS, LNMC, and LRMC were −4.91 (0.63), −1.19 (1.27), 0.91 (0.54), and −3.43 (0.47), respectively. Heritability estimates (SE) for LNDS, LNMC, LRMC, SKDS, NBRD, NNCD, INBR, AFBR, and BW were 0.02 (0.006), 0.25 (0.015), 0.09 (0.009), 0.01 (0.004), 0.09 (0.009), 0.05 (0.009), 0.06 (0.008), 0.06 (0.008), and 0.34 (0.018), respectively. Among the resilience indicators, LRMC showed the most favorable genetic correlations with the health traits (positive with INBR: 0.22 (0.085) and NBRD: 0.23 (0.077), positive with NNCD: 0.13 (0.099), and negative with AFBR: −0.22 (0.085)). This supports the interpretation that greater proportional day-to-day variability in milk intake is associated with higher disease burden and earlier BRD occurrence (i.e., lower resilience). These results demonstrate that AMF-derived milk feeding metrics can serve as useful indicators of calf resilience and may be incorporated into breeding programs aimed at reducing susceptibility to BRD and NCD.

Keywords: 2026

How to Cite:

Aktar, M., Maskal, J., Taghipoor, M. & Brito, L., (2026) “Genetics of calf resilience indicators derived from automated milk feeder data and their genetic relationship with respiratory and enteric diseases in American Holstein cattle”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2287129. doi: https://doi.org/10.31274/wcgalp.24217

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