Effect of plane of nutrition during the first 12 weeks of life on growth, metabolic and reproductive hormone concentrations, and testicular relative mRNA abundance in preweaned Holstein Friesian bull calves

Abstract

The objective of this study was to examine the effect of nutrition during the first 12 wk of life on aspects of the physiological and transcriptional regulation of testicular and overall sexual development in the bull calf. Holstein Friesian bull calves with a mean ±SD age and bodyweight of 17.5 (2.85) days and 48.8 (5.30) kg, respectively, were assigned to either a high (HI; n=15) or moderate (MOD; n=15) plane of nutrition and were individually fed milk replacer and concentrate to achieve overall target growth rates of at least 1.0 and 0.5 kg/day, respectively. Throughout the trial, animal growth performance, feed intake, and systemic concentrations of metabolites, metabolic and reproductive hormones were assessed. Additionally, pulsatility of reproductive hormones (luteinising hormone (LH), follicle stimulating hormone (FSH) and testosterone (TT) was recorded at 15 min intervals during a 10-h period at 10 wk of age. At 87 ± 2.14 days of age, all calves were euthanized, testes weighed, and testicular tissue harvested. Differential expression of messenger ribonucleic acid (mRNA) candidate genes involved in testicular development was examined using quantitative polymerase chain reaction (qPCR) assays. All data were analysed using the MIXED procedure in Statistical Analysis System (SAS) using terms for treatment as well as time for repeated measures. Blood metabolites and metabolic hormones generally reflected the improved metabolic status of the calves on the high plane of nutrition though the concentrations of reproductive hormones were not affected by diet. Calves offered HI had greater mean (SED) slaughter weight (112.4 v 87.70 (2.98) kg; P < 0.0001) and testicular tissue weight [29.2 v 20.1 (2.21) g; P = 0.0003], than MOD. Relative mRNA abundance data indicated advanced testicular development through up-regulation of genes involved in cellular metabolism (SIRT1; P = 0.0282), cholesterol biosynthesis (EBP; P = 0.007), testicular function (INSL3; P = 0.0077) and Sertoli cell development (CLDN11; P = 0.0054) in HI compared with MOD calves. In conclusion, results demonstrate that offering dairy bred male calves a high plane of nutrition during the first three months of life not only improves growth performance and metabolic status, but also advances testicular development consistent with more precocious sexual maturation.

Early life nutrition affects the molecular ontogeny of testicular development in the young bull calf

“…This is further established through upstream analysis using IPA, where testosterone was predicted to regulate the expression of CYPB26B1, NTRK1 and TF. Indeed, systemic concentrations of testosterone were greater in the HI calves in the current study 10 . Moreover, a relationship between the three aforementioned genes and testicular development in early life was recently established through co-expression network analysis, whereby a network containing CYPB26B1, NTRK1 and TF which was positively associated with greater Sertoli cell number, more advanced stage of spermatogenesis and greater concentrations of testosterone in the testes of bull calves fed an enhanced diet up to 18 weeks of age 24 .…”

“…2 highlights an interaction between these genes and androgen receptor (AR), further implicating DEGs in this study with testicular development. Indeed systemic concentrations of testosterone were greater in the HI calves used in the current study 10 which may have led to the differential expression of genes within Fig. 2 .…”

“…The animal model and general management regimen pertaining to the animals used in this study have previously been extensively described 10 . Briefly, thirty Holstein–Friesian bull calves with a mean (± SD) age and bodyweight of 17.5 (± 2.85) days and 48.8 (± 5.3) kg, respectively, were sourced from four commercial dairy farms and blocked on age, sire, liveweight and farm of origin.…”

Multifaceted Interplay among Social Dominance, Body Condition, Appetitive and Consummatory Sexual Behaviors, and Semen Quality in Dorper Rams during Out-Of-Season and Transition Periods

“…Interestingly, not only social dominance but testosterone concentrations and aggressiveness have been strongly associated with widely distributed testosterone receptors at the hypothalamic level [ 43 ]. Furthermore, and from a central molecular point of view, in males with a better metabolic status and BCS, four particular genes were upregulated: (1) SIRT1 , involved in cellular metabolism, (2) EBP , related to cholesterol biosynthesis, (3) INSL3 , linked to testes development, and (4) CLDN , aligned to Sertoli cell development [ 44 ]. Recently, the possible role of specific genotypes of the melatonin receptor 1A (i.e., MTNR1A ) gene in social dominance and reproductive success was tested in rams.…”

The Distribution, Expression Patterns and Functional Analysis of NR1D1 and NR4A2 in the Reproductive Axis Tissues of the Male Tianzhu White Yak

“…Thus, there is a pressing need to clarify the yak reproductive mechanisms to improve reproductive performance. Reproductive hormones strictly regulate the reproductive process in animals [6,7], and the complex functions and regulatory roles of hormones have been in-depth for many years [8,9]. However, there is a lack of consensus regarding the changes and regulatory mechanisms of reproductive hormones as some mechanisms remain.…”