Residual feed intake and reproductive traits of growing Purunã bulls

Kowalski, Luciana Helena; Fernandes, Sérgio Rodrigo; DiLorenzo, Nicolás; Moletta, José Luiz; Rossi, Paulo; Freitas, José Antônio de

doi:10.2527/jas2016.0888

Cited by 2 publications

(4 citation statements)

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“…The mean SC did not differ between low and high RFI animals. Similar results have been reported in previous studies comparing bulls with distinct RFI values (Ha a et al, 2013;Wang et al, 2012;Fontoura et al, 2016;Kowalski et al, 2017). On the other hand,Awda et al (2013) andBourgon et al (2018) observed a greater SC in high RFI animals but the difference decreased when the animals received betterquality diet, suggesting that this difference in reproductive parameters between low and high RFI animals is due to the energy distribution for maintenance and production and reproductive traits.…”

supporting

confidence: 89%

“…Within this context, some studies observed lower echogenicity in low RFI animals when compared to high RFI animals, a nding that may indicate lower cellularity (Fontoura et al, 2016;Bourgon et al, 2018). On the other hand, Kowalski et al (2017) found no difference between animals with distinct RFI.…”

Section: Introductionmentioning

confidence: 98%

“…Within this context, reports suggest that young bulls with low RFI (most e cient) produce ejaculates characterized by lower sperm motility (Awda et al, 2013) and lower semen quality based on sperm morphology (Ha a et al, 2013; Awda et al, 2013). However, Rossi (2017) and Kowalski et al (2017) found no effect of RFI on the reproductive parameters of young bulls.…”

Section: Introductionmentioning

confidence: 99%

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

Borges

Silva

Fernandes

et al. 2022

Preprint

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Residual feed intake (RFI) is one of the main tools used to identify feed efficiency. However, there is no consensus on the true impact of RFI on male reproductive traits in cattle. The study aimed 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 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 (P=0.061) 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 (P=0.0652) 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 to 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 to high RFI animals (12.29±2.71%). In conclusion, although RFI exerts an effect on the Doppler parameters of the pampiniform plexus, it was not sufficient to affect the quality of fresh or thawed semen.

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supporting

confidence: 89%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

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

Borges

Silva

Fernandes

et al. 2022

Preprint

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“…Certain studies have reported an unfavourable relationship between RFI status and some (Wang et al 2012;Awda et al, 2013) but not all (Awda et al, 2013) estimates of semen quality. In addition, other studies have shown no effect of RFI rank on scrotal circumference, a measure of spermatogenic potential (Awda et al, 2013;Fontoura et al, 2015, Kowalski et al, 2017 or indeed systemic concentrations of testosterone (Kowalski et al, 2017). Within the context of multi-sire groups on pasture, Wang et al (2012) concluded that there was no evidence for a detrimental effect of selection for improved feed efficiency on the reproductive performance of beef bulls.…”

Section: Maternal Traits and Fertilitymentioning

confidence: 98%

Invited review: Improving feed efficiency of beef cattle – the current state of the art and future challenges

Kenny

Fitzsimons

Waters

et al. 2018

Animal

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Improvements in feed efficiency of beef cattle have the potential to increase producer profitability and simultaneously lower the environmental footprint of beef production. Although there are many different approaches to measuring feed efficiency, residual feed intake (RFI) has increasingly become the measure of choice. Defined as the difference between an animal's actual and predicted feed intake (based on weight and growth), RFI is conceptually independent of growth and body size. In addition, other measurable traits related to energy expenditure such as estimates of body composition can be included in the calculation of RFI to also force independence from these traits. Feed efficiency is a multifactorial and complex trait in beef cattle and inter-animal variation stems from the interaction of many biological processes influenced, in turn, by physiological status and management regimen. Thus, the purpose of this review was to summarise and interpret current published knowledge and provide insight into research areas worthy of further investigation. Indeed, where sufficient suitable reports exist, meta-analyses were conducted in order to mitigate ambiguity between studies in particular. We have identified a paucity of information on the contribution of key biological processes, including appetite regulation, post-ruminal nutrient absorption, and cellular energetics and metabolism to the efficiency of feed utilisation in cattle. In addition, insufficient information exists on the relationship between RFI status and productivity-related traits at pasture, a concept critical to the overall lifecycle of beef production systems. Overall, published data on the effect of RFI status on both terminal and maternal traits, coupled with the moderate repeatability and heritability of the trait, suggest that breeding for improved RFI, as part of a multi-trait selection index, is both possible and cumulative, with benefits evident throughout the production cycle. Although the advent of genomic selection, with associated improved prediction accuracy, will expedite the introgression of elite genetics for feed efficiency within beef cattle populations, there are challenges associated with this approach which may, in the long-term, be overcome by increased international collaborative effort but, in the short term, will not obviate the on-going requirement for accurate measurement of the primary phenotype.

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Residual feed intake and reproductive traits of growing Purunã bulls

Cited by 2 publications

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

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

Invited review: Improving feed efficiency of beef cattle – the current state of the art and future challenges

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