Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Animal Science

First Advisor

Cody Wright


bulls, heifers, water intake, weather


Research conducted in the 1950s to determine water requirements utilized cattle that vary greatly from the animals being raised today. Additionally, most of the previous research has been conducted on animals being fed for slaughter, rather than bulls or reproductive females. The objective of this study was to analyze the effect of weather variables, dry matter intake (DMI), and body weight (BW) on total daily water intake (TDWI) and liquid daily water intake (LDWI) in growing beef bulls and heifers. Two contemporary groups of Angus and Simmental x Angus bulls and heifers over a two-year period were utilized in this study. Animals were housed in an open front monoslope building at the South Dakota State University (SDSU) Cow Calf Education and Research Facility (CCERF) from November to February in respective years. Feed and water disappearance (assumed to be intake) was collected utilizing an Insentec RIC (roughage intake control) system. Body weights were taken every 28 d to determine average daily gain (ADG) and predict daily BW during the duration of the study. Daily weather variables were collected from the South Dakota Mesonet station located 3.86 km from the CCERF. All variables were tested for multicollinearity and significance for predicting TDWI and LDWI in a standard mixed linear regression. Due to this factor, all variables discussed are significant (P ≤ 0.05). The PROC-MIXED procedure of SAS (version 9.4) was utilized to build linear mixed models to predict TDWI and LDWI. Year 1 was utilized for model building with Year 2 being used for model validation. A linear mixed model with a compound symmetry (CS) covariance structure offered a prediction that fit the data well. Average relative humidity, wind speed, wind chill, and DMI were predictors for TDWI and LDWI in bulls and heifers. In bulls, BW was an effective predictor for TDWI and LDWI. In heifers, BW was an effective predictor for LDWI and SRAD was an effective predictor for TDWI and LDWI. These models will be useful for predicting TDWI and LDWI in growing beef bulls and heifers that are raised in areas that experience similar winter weather conditions.

Library of Congress Subject Headings

Beef cattle -- Water requirements.
Beef cattle -- Climatic factors.
Beef cattle -- Feeding and feeds.
Beef cattle -- Weight.


South Dakota State University

Included in

Beef Science Commons



Rights Statement

In Copyright