Stabilizing Total Mixed Ration Dry Matter to Mitigate Environmental-Relative-Humidity Effects on Lactating Cow Performance
Journal
Animals
Journal Volume
15
Journal Issue
8
Start Page
1137
ISSN
2076-2615
Date Issued
2025-04-15
Author(s)
Abstract
This study evaluated environmental relative humidity’s (ERH) impact on dry matter (DM) in hay and total mixed ration (TMR), exploring strategies to stabilize milk production in lactating cows by maintaining a consistent TMR DM content. We hypothesized that precise TMR DM adjustments mitigate ERH effects on milk production stability. Experiment 1 showed that grass hay exhibited greater DM variability than alfalfa hay under high ERH. Experiment 2 revealed that high daily ERH variability (>25%) caused fluctuations in hay moisture, affecting TMR DM stability. Increasing TMR DM reduced milk composition variation. In Experiment 3, precise TMR DM adjustments and heat stress levels were evaluated under different temperature–humidity indexes (THIs) in 46 cows over three 28-day periods. The results showed a significant improvement in milk yield (non-adjustment: 26.99 vs. adjustment: 27.29; SEM: 0.32; THIs: 65 to 82; p < 0.05) and a reduction in the variation in milk composition under heat stress. The differences in energy-corrected milk were lower (non-adjustment: 0.47 ± 0.06 vs. adjustment: 0.20 ± 0.09; p < 0.05). This study confirmed that monitoring hay DM and adjusting TMR DM stabilize milk production under variable ERH. Dairy producers can implement routine hay DM monitoring and TMR adjustments to enhance lactating cows’ performance.
Subjects
dry matter
energy-corrected milk
hay
moisture stabilization
precision feeding
temperature–humidity indexes
Publisher
MDPI AG
Description
Article number: 1137
Type
journal article