Associations between body temperature and feed efficiency traits in lactating Holstein cows

Authors: CAVANI, LIGIA - University Of Wisconsin; NOVO, LARISSA - University Of Wisconsin; REYES, FAITH - University Of Wisconsin; NASCIMENTO, BARBARA - University Of Wisconsin; VANDEHAAR, MICHAEL - Michigan State University; TEMPELMAN, ROBERT - Michigan State University; PARKER GADDIS, KRISTEN - Council On Dairy Cattle Breeding; Baldwin, Ransom; SANTOS, JOSE - University Of Florida; KOLTES, JAMES - Iowa State University; WHITE, HEATHER - University Of Wisconsin; WEIGEL, KENT - University Of Wisconsin; PENAGARICANO, FRANCISCO - University Of Wisconsin

Submitted to: Journal of Dairy Science Communications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/18/2024
Publication Date: 3/1/2025
Citation: Cavani, L., Novo, L.C., Reyes, F.S., Nascimento, B.M., VandeHaar, M.J., Tempelman, R.J., Parker Gaddis, K.L., Baldwin, R.L., Santos, J.E., Koltes, J.E., White, H.M., Weigel, K.A., Penagaricano, F. 2025. Associations between body temperature and feed efficiency traits in lactating Holstein cows. Journal of Dairy Science Communications. 6(2):256-260. https://doi.org/10.3168/jdsc.2024-0701.
DOI: https://doi.org/10.3168/jdsc.2024-0701

Interpretive Summary: Differences in feed efficiency among animals could be partially explained by changes in body temperature due to the digestion process. We studied the relationship between average body temperature, consistency of body temperature, and the change in body temperature after the largest meal of the day, with 4 feed efficiency traits: Dry matter intake, energy of the milk produced, body weight (adjusted by a factor to generate metabolic BW), and residual feed intake (RFI is a measure of efficiency) in lactating Holstein cows. Data were collected from 1,068 mid-lactation Holstein cows enrolled in 36 feed efficiency trials from 2020 to 2023 at five research stations across the United States. Temperature records were obtained using an automatic temperature logger placed vaginally for 2 wk. The associations between body temperature traits and feed efficiency traits were assessed using univariate linear regression models including body temperature, cohort (trial-treatment), and temperature humidity index (THI) as independent variables and correlations between body temperature and feed efficiency traits were calculated. Additionally, the effect of body temperature traits on RFI calculation was also evaluated. Higher body temperature was significantly associated with lower DMI and lower metabolic BW. Consistency of body temperature was positively associated with DMI and milk energy, showing that greater variance in body temperature is linked to more DMI and, consequently, more milk energy. Smaller changes in body temperature after the largest meal were associated with lower DMI, milk energy, and RFI, indicating that more feed efficient cows maintain more stable body temperatures. Adding body temperature traits to the RFI model did not change the R^2, which remained around 0.86. Overall, our results suggest that body temperature does not provide value as an additional energy sink, but it is associated with feed efficiency in mid-lactation dairy cows through its relationships with DMI and metabolic BW. More feed-efficient cows may regulate their body temperature more effectively, showing lower variation in body temperature, especially after large meals.

Technical Abstract: Differences in feed efficiency among animals could be partially explained by changes in body temperature due to the digestion process. The aim of this study was to investigate the associations between 3 body temperature traits, namely average body temperature, consistency of body temperature, and change in body temperature after the largest meal of the day, with 4 feed efficiency traits: DMI, milk energy, metabolic BW, and residual feed intake (RFI) in lactating Holstein cows. Data were collected on 1,068 mid-lactation Holstein cows enrolled in 36 feed efficiency trials from 2020 to 2023 at five research stations across the United States. Temperature records were obtained using an automatic temperature logger placed vaginally for 2 wk. Average body temperature was calculated as the individual mean, daily and over the 2 wk. period, consistency of body temperature was calculated as the log-transformed variance of the deviations of individual records from the cow’s mean and change in body temperature was calculated as the difference in the temperature after and before the largest meal of the day. Data for DMI, milk energy, metabolic BW, and RFI were collected from the same cows for 6 to 7 wk. in the same feeding trials. The associations between body temperature traits and feed efficiency traits were assessed using univariate linear regression models including body temperature, cohort (trial-treatment), and temperature humidity index (THI) as independent variables. Pearson’s correlations between body temperature and feed efficiency traits were calculated. Additionally, the effect of body temperature traits on RFI calculation was also evaluated. Higher body temperature was significantly associated with lower DMI and lower metabolic BW. Consistency of body temperature was positively associated with DMI and milk energy, showing that greater variance in body temperature is linked to more DMI and, consequently, more milk energy. Smaller changes in body temperature after the largest meal were associated with lower DMI, milk energy, and RFI, indicating that more feed efficient cows maintain more stable body temperatures. Adding body temperature traits to the RFI model did not change the R^2, which remained around 0.86. Overall, our results suggest that body temperature does not provide value as an additional energy sink, but it is associated with feed efficiency in mid-lactation dairy cows through its relationships with DMI and metabolic BW. More feed-efficient cows may regulate their body temperature more effectively, showing lower variation in body temperature, especially after large meals.