Sexual maturity and fertility-related measures in young Nellore bulls receiving long-term dietary supplementation with rumen-protected polyunsaturated fatty acids

Author(s):Show less -

Rossi, Guilherme Fazan ^[1] ; Ribeiro Dias, Erika Aline ^[2] ; Bastos, Natalia Marins ^[1] ; Vrisman, Dayane Priscila ^[1] ; Rodrigues, Naiara Nantes ^[1] ; Vantini, Roberta ^[1] ; Garcia, Joaquim Mansano ^[1] ; Simili, Flavia Fernanda ^[2] ; Ribeiro, Enilson Geraldo ^[2] ; Canesin, Roberta Carrilho ^[2] ; Zerlotti Mercadante, Maria Eugenia ^[2] ; Freitas-Dell'Aqua, Camila P. ^[3] ; Monteiro, Fabio Morato ^{[1, 2]} ; Mingoti, Gisele Zoccal ^{[1, 4]}

Affiliation

^[1] Sao Paulo State Univ UNESP, Sch Agrarian & Vet Sci, Grad Program Vet Med, Campus Jaboticabal, Sao Paulo - Brazil

^[2] Inst Anim Sci IZ, Sao Paulo Agribusiness Technol Agcy APTA, Sao Paulo - Brazil

^[3] Sao Paulo State Univ UNESP, Sch Vet Med & Anim Sci, Dept Anim Reprod & Vet Radiol, Campus Botucatu, Sao Paulo - Brazil

^[4] Sao Paulo State Univ UNESP, Sch Vet Med, Lab Reprod Physiol, Campus Aracatuba, Sao Paulo - Brazil

• Document type: Journal article
• Source: Theriogenology; v. 139, p. 16-27, NOV 2019.
• Web of Science Citations: 0

Abstract

The objective of this study was to evaluate the effects of long-term supplementation with rumen protected fatty acids (FA) on growth and reproductive parameters of young Nellore bulls in a grazing regime. Forty-eight young bulls were distributed into two groups: FA (supplemented with rumen protected polyunsaturated FA); and control (control fat-free supplement). The animals were supplemented from 14.3 to 24.6 months of age and growth and reproductive parameters were evaluated at 28 day intervals. The semen was cryopreserved in the last collection and fresh and post-thaw semen samples were evaluated. Feeding FA did not affect (P>0.05) growth, reproductive parameters (scrotal circumference, sperm concentration per mL of ejaculate, percentage of sperm defects, sperm quality and fertility in vitro), or testicular ultrasonographic characteristics. However, thawed semen from bulls fed FA exhibited better quality (P < 0.05) than control semen for the following parameters evaluated by computer-assisted sperm analysis: average path velocity (mu/s: 90.48 vs. 79.66 post-thaw and 74.81 vs. 72.80 post-rapid thermoresistance test (TRT)], straight-line velocity (mu/s: 72.37 vs. 65.20 post-thaw and 64.96 vs. 63.25 post-TRT), and curvilinear velocity (mu m/s: 148.44 vs. 131.31 post-thaw and 115.68 vs. 113.35 post-TRT). In addition, feeding FA increased peripheral concentrations of testosterone, leptin, total cholesterol and high-density lipoprotein. In conclusion, the increase in testosterone concentrations in bulls fed FA was not related to variations in growth parameters and sexual maturity. In addition, post thawing sperm velocities were enhanced by diet, however, such increases were not related to better in vitro embryo production rates. (C) 2019 Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 15/06733-5 - Evaluation of seminal characteristics in Nellore bulls selected for residual feed intake and supplemented with polyunsaturated fatty acids in pasture conditions
• Grantee: Gisele Zoccal Mingoti
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/13696-3 - REPRODUCTIVE PARAMETERS OF NELORE MALES OF LOW AND HIGH FEED EFFICIENCY SUPPLEMENTS WITH PROTECTED FATTY ACIDS IN PASTURE
• Grantee: Guilherme Fazan Rossi
• Support Opportunities: Scholarships in Brazil - Doctorate