Session: Production, Management, and Environment II

282 - Nutritional Monitoring of Prenatally Stressed and Translocated Brahman Heifers

Friday, July 16, 2021

2:00 PM – 2:15 PM EST

Location: Kentucky International Convention Center (KICC), L007/008

Presenting Author(s)

Douglas R. Tolleson

Associate Professor
Texas A&M AgriLife
Sonora, Texas

PDF Slides and Audio

Author(s)

RR

Ron D. Randel, Ph.D.

Professor
Texas A&M AgriLife Research, Overton
Overton, Texas
GP

George A. Perry

Texas A&M AgriLife Research, Overton
Overton, Texas
JD

Jose M. Diaz

Visiting Professor
Southern Arkansas University
Fayetteville, Arkansas
HS

Heath D. Starns

Post Doctoral Scientist
Texas A&M AgriLife
Sonora, Texas
CK

Colt W. Knight

Assistant Extension Professor & State Livestock Specialist
The University of Maine
Orono, Maine
NG

Nick E. Garza

SR Research Associate
Texas A&M AgriLife, Sonora
Sonora, Texas
SB

Sarah L. Beall

Research Assistant
Texas A&M AgriLife, Sonora
Sonora, Texas
DN

Don A. Neuendorff, M.S.

Research Associate
Texas A&M AgriLife Research, Overton
Overton, Texas
TW

Thomas H. Welsh, Jr.

Professor
Texas A&M University; Texas A&M AgriLife Research, College Station
College Station, Texas

One drought mitigation strategy is transporting livestock to non-drought locations. Our objective was to evaluate the effects of prenatal stress and translocation on growing Bos indicus heifers. Twelve heifers born in spring 2019 at Overton, TX (1245 mm annual precipitation) were transported ~700 km to Sonora, TX (610 mm annual precipitation) in April 2020. Six heifers (283±10 kg) were born to dams subjected to transportation stress during mid-gestation (PNS) and 6 (279±17 kg) were born to non-stressed dams (CON). Heifers grazed a series of 24-ha native range pastures (aboveground forage biomass; 1508±390 kg/ha) and were sampled (non-shrunk BW/BCS score, feces) at 2-wk intervals from May through September. Fecal samples were collected from the ground or the rectum of each animal and stored at -20^o C until processed for near infrared spectroscopy (NIRS) and prediction of diet crude protein (CP) and digestible organic matter (DOM). Inputs to a grazing animal nutrition model for prediction of BW included diet CP and DOM, age, and weather. Differences between groups for BW and nutritional parameters were determined by analysis of variance or paired t-test. Both groups gained BW (22±4 kg) throughout the study, there were no differences (P > 0.1) due to treatment. Diet CP and DOM were affected by date (P < 0.01) as diet quality declined from spring to fall. Percent diet CP was greater (P < 0.05) in PNS than CON, especially during July and August (6.94±0.10 vs 6.23±0.17, respectively). Corresponding values for diet DOM were (59.53±0.55 vs 59.14±0.43, respectively; P = 0.09). Observed vs model-predicted weight was different (P < 0.05) for both groups when using CP-based outputs, but not when using metabolizable protein-based outputs (P > 0.1). In summary, PNS heifers selected a diet of greater CP than CON, and tended to select a diet greater in DOM.