Relationship of residual feed intake with semen parameters and testicular ultrasound of Nellore bulls

Author(s)

Marcelo SantAna Borges ^[1] ; Marina de Oliveira Silva ^[2] ; Luana Gomes Fernandes ^[3] ; Naiara Nantes Rodrigues ^[4] ; Guilherme Fazan Rossi ^[5] ; Camila de Paula Freitas-DellAqua ^[6] ; Sarah Figueiredo Martins Bonilha ^[7] ; Maria Eugênia Zerlotti Mercadante ^[8] ; Fabio Morato Monteiro

Affiliation

^[1] Instituto de Zootecnia. Centro Avançado de Pesquisa de Bovinos de Corte - Brasil

^[2] Instituto de Zootecnia. Centro Avançado de Pesquisa de Bovinos de Corte - Brasil

^[3] Universidade Estadual Paulista “Júlio de Mesquita Filho”. Faculdade de Ciências Agrárias e Veterinárias - Brasil

^[4] Universidade Estadual Paulista “Júlio de Mesquita Filho”. Faculdade de Ciências Agrárias e Veterinárias - Brasil

^[5] Universidade Estadual Paulista “Júlio de Mesquita Filho”. Faculdade de Ciências Agrárias e Veterinárias - Brasil

^[6] Universidade Estadual Paulista “Júlio de Mesquita Filho”. Faculdade de Medicina Veterinária e Zootecnia - Brasil

^[7] Instituto de Zootecnia. Centro Avançado de Pesquisa de Bovinos de Corte - Brasil

^[8] Instituto de Zootecnia. Centro Avançado de Pesquisa de Bovinos de Corte - Brasil

• Document type: Journal article
• Source: REVISTA BRASILEIRA DE ZOOTECNIA-BRAZILIAN JOURNAL OF ANIMAL SCIENCE; v. 52, 2023-06-23.

Abstract

ABSTRACT The objective of this study was to evaluate characteristics of the testicular parenchyma and vascular parameters of the pampiniform plexus obtained by ultrasound, semen quality parameters, and sperm freezability in Nellore bulls classified based on residual feed intake (RFI). Twenty-seven bulls (21.82±0.88 months of age) evaluated for feed efficiency were sampled for the study, including 15 with low RFI (−0.592±0.09 kg dry matter/day) and 12 with high RFI (0.792±0.10 kg dry matter/day). In ultrasound and Doppler assessment, the most efficient animals (low RFI) showed higher pulsatility and resistive indexes, as well as a tendency towards greater heterogeneity of the testicular parenchyma (0.625±0.032 vs. 0.508±0.032, 1.012±0.072 vs. 0.802±0.072, and 12.9±0.96 vs. 10.2±0.96, respectively, for low vs. high RFI). However, these animals tended to have lower peak diastolic velocity (5.19±0.50 for low RFI vs. 6.54±0.50 for high RFI). Analysis of fresh semen showed a lower percentage of minor defects in low RFI animals (2.67±1.19%) compared with high RFI animals (8.10±1.19%), without differences in the other parameters in fresh or thawed semen and after thermoresistance testing. Evaluation of flow cytometry parameters showed a higher quality of mitochondrial respiration in semen samples of low RFI animals (22.04±2.50%) compared with high RFI animals (12.29±2.71%). Therefore, although RFI exerts an effect on the Doppler parameters of the pampiniform plexus, it is not sufficient to affect the quality of fresh or thawed semen. (AU)

• FAPESP's process: 17/50339-5 - Institutional research development plan of the Animal Science Institute (PDIp)
• Grantee: Lenira El Faro Zadra
• Support Opportunities: Research Grants - State Research Institutes Modernization Program