Session: Production, Management, and Environment II

281 - The Effects of Whole Cottonseed Supplementation on Performance, Breeding Soundness Exams, and Manganese Superoxide Dismutase Concentrations in the Blood and Semen of Beef Bulls

Friday, July 16, 2021

3:00 PM – 3:15 PM EST

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

Presenting Author(s)

Dylan B. Davis, MS

PhD Student
University of Georgia, Animal and Dairy Science
Athens, Georgia

PDF Slides and Audio

Author(s)

LJ

Lee Jones

University of Georgia
Tifton, Georgia
SH

Shane R R. Hernandez

University of Georgia, Animal and Dairy Science
Athens, Georgia
CW

Christina B. Welch

University of Georgia
Athens, Georgia
Jennifer J. Tucker, PhD

Associate Professor
University of Georgia, Department of Animal Science
Tifton, Georgia
Pedro Fontes, PhD

Assistant Professor
University of Georgia
Athens, Georgia
Matthew P. Holton, n/a

Graduate Student
University of Georgia
Athens, Georgia
RS

R. Lawton Stewart

University of Georgia, Animal and Dairy Science
Athens, Georgia

The objective of this research was to determine the effects of whole cottonseed containing gossypol on post-pubertal beef bulls. In a two-year study, 46 Angus and Red Angus bulls (body weight 457.0 ± 85.2 kg; 16 to 20-months of age) were stratified by BW and randomly assigned to 1 of 3 levels of whole cottonseed supplementation while receiving ad libitum roughage. The treatments included: DD (n = 14, control; 3.18 kg/d of dried distillers grain, W/D (n = 16; 1.59 kg/d of whole cottonseed and 1.59 kg/d of dried distillers grain), or WW (n = 16 3.18 kg/d of whole cottonseed). Diets were formulated to be isocaloric and isonitrogenous. In both years, bulls were weighed, administered a breeding soundness exam, and morphological characteristics of spermatozoa were measured on d 0, 28, and 60. In year 1, blood and semen samples were collected on d 0, 28, and 60 to measure manganese superoxide dismutase activity. There was no treatment effect for blood or semen manganese superoxide dismutase concentration (P > 0.255). There was a treatment effect (P < 0.02) for average daily gain as bulls fed WW gained less compared to those fed WD and DD (0.96, 1.23, and 1.39 kg/d, respectively). No treatment effect was observed for scrotal circumference (P > 0.50). There were no treatment × time interactions, treatment, or time main effects for percentages of normal spermatozoa, spermatozoa with coiled or folded tails, or proximal droplets (P > 0.12). There was a treatment effect on the amount of swollen midpiece or abnormal head as bull in the DD treatment had a greater (P < 0.02) percentage of other abnormalities compared to WW, but WD was not different (P > 0.16). Inclusion of whole cottonseed may affect average daily gain, but does not affect reproductive parameters of beef bulls.