Effects of whole cottonseed supplementation on performance, semen quality, and manganese superoxide dismutase concentrations in blood and semen of beef bulls

• Published in: Applied Animal Science 2022-12, Vol.38 (6), p.533-539
• Main Authors: Davis, D.B., Jones, A.L., Hernandez, S.R., Welch, C.B., Fontes, P.L.P., Tucker, J.J., Stewart, R.L.
• Format: Article
• Language: English
• Subjects: beef cattle; manganese superoxide dismutase; semen quality exam; spermatozoa
• ISSN: 2590-2865; 2590-2865
• DOI: 10.15232/aas.2022-02303

This research aimed to determine the effects of whole cottonseed on performance, semen quality, and manganese superoxide dismutase (MnSOD) concentrations in the blood and semen of beef bulls. In a completely randomized design, 46 (BW = 457 ± 12 kg; 16–18 mo old) Angus bulls were stratified by BW and randomly assigned to 1 of 3 treatments: DD (n = 14, control; 3.18 kg/d dried distillers grain), WD [n = 16; 1.59 kg/d whole cottonseed (0.56 and 0.82% free gossypol in yr 1 and 2, respectively) and 1.59 kg/d dried distillers grain], or WW (n = 16; 3.18 kg/d whole cottonseed). Bulls were weighed and blood and semen were sampled on d 0, 30, and 60. Body weights and morphological characteristics of spermatozoa were measured in both years, and MnSOD concentrations of blood and semen were measured in yr 1. There was a treatment effect for ADG (P = 0.002) as bulls fed WW had a decreased (P < 0.03) ADG compared with bulls fed WD and DD. A time effect was observed for scrotal circumference (P < 0.001). Scrotal circumference measurements increased on d 60 compared with d 0 and 28 (P ≤ 0.02). There was no time main effect for percentage of spermatozoa with other abnormalities (P = 0.87); however, there was a treatment effect (P = 0.04). Bulls in the WW treatment had fewer other abnormalities than bulls in DD (P = 0.01) but were not different than WD (P = 0.27). Whole cottonseed did not affect reproductive parameters measured in this study or blood and semen concentrations of MnSOD. According to these results, WCS supplemented to beef bulls at 0.7% of BW for 60 d may not negatively affect semen quality or MnSOD concentrations in the blood or semen.