Investigation of Gestational Environmental Impacts on Individual Calf Growth and Development in Beefmaster Cattle

This study evaluated seasonal temperature and precipitation effects during gestation on weaning weights (WWT) and birthdates of Beefmaster calves (N = 665) born to Beefmaster dams (N = 328) from 2018-2021 in a privately owned purebred Beefmaster operation. The calves were born and raised on six leased ranches within 150 km of San Angelo, Texas. Both Fall- and Spring-calving herds were evaluated with weaning dates of approximately April 15 and October 15 each year. Relative to calf birthdate, month of birth and month of gestation were evaluated for historical average vs. 0.67 standard deviation for temperature and precipitation. Mean weaning age was 231 days, and 53 sires were represented. Weaning age (P < 0.001), age of the dam (P < 0.001), year (P < 0.001), and calf sex (P < 0.001) influenced WWT. The interaction between year and season impacted WWT for each month of gestation and calving considered (P < 0.001). Monthly average precipitation (MAP) during the first (P = 0.014) and last month (P = 0.005) of gestation influenced WWT by 10 kg and 19.6 kg, respectively. MAP during calf birth month also affected WWT (P = 0.027) by as much as 17 kg. Age of dam influenced calf Julian birthdate (JBD) for each calendar month of the year (P < 0.001), as did calf sex (P = 0.018-0.026). Calving season impacted JBD when months of January (P = 0.022), April (P = 0.054), and May (P = 0.022) were evaluated. Monthly average temperature impacted JBD for the month of April (P = 0.04) by 4 days. With MAP included in the model, the age of the dam influenced JBD (P < 0.001), as did calf sex (P = 0.019 to 0.034). Calving season had an impact on JBD when the months of March (P = 0.035), August (P = 0.035), and October (P = 0.014) were evaluated. These results indicate that climatic conditions might be considered for comparing performance records across location and time, and may be considered for more refined contemporary group comparisons for field data collected by breed associations.

Name thesis:degree_name

Master of Science

Discipline thesis:degree_discipline

Animal Science

Grantor

Texas A&M University

Year dc:date.issued

2025

Author dc:creator

• McClendon, Carter Trace 2000-

Advisor dc:contributor.advisor

• Herring, Andy

Committee members dc:contributor.committeemember

• Anderson, David
• Goodwin, Douglas
• Wickersham, Tryon

• Agriculture, General

Language dc:language.iso

English

Handle dc:identifier.uri

https://hdl.handle.net/1969.1/1599836

OAI record oai:identifier

https://oaktrust.library.tamu.edu/server/oai/request?verb=GetRecord&metadataPrefix=dim&identifier=oai%3Aoaktrust.library.tamu.edu%3A1969.1%2F1599836