Project description:The objectives of the study were to use RNA-Seq to examine the effect of (i) breed and (ii) gradual weaning, on the whole blood mRNA transcriptome of artificially reared Holstein-Friesian and Jersey calves. The calves were gradually weaned over 14 days (day (d) -13 to d 0) and mRNA transcription was examined one day before gradual weaning was initiated (d -14), one day after weaning (d 1) and 8 days after weaning (d 8). RNA-seq analysis was carried out on RNA extracted from whole blood. Gradual weaning had no effect on gene expression (P>0.05).There were 550 differentially expressed genes at a false discovery rate of 10% and with a â¥1.5-fold change, between Holstein-Friesian and Jersey calves on d -14, 490 on d 1, and 411 on d 8. GOseq/KEGG pathway analysis showed that the cytokine-cytokine receptor interaction pathway and the neuroactive ligand-receptor interaction pathway were over-represented between breeds on all days (P<0.01; Qâ¤0.1). These results demonstrate that the gradual weaning practiced here does not compromise the welfare of artificially-reared dairy calves, evidenced by the lack of expression changes in any genes in response to gradual weaning. These data also suggest differences in cell signalling and immune responses between breeds. Eight Holstein-Friesian and eight Jersey bull calves were group housed indoors and individually fed milk replacer and concentrate using an automatic feeder. Calves were gradually weaned by reducing milk-replacer from 6 litres to 0 litres over 14 days (d) (d -13 to d 0). Calves were blood sampled on d -14, 1, and 8, relative to weaning (d 0). RNA-seq analysis was carried out on RNA extracted from whole blood.
Project description:The aim of this study was to measure the impact of contrasting feeding regimes in the first 12 wk of life, known to impact age at puberty on the molecular control of the testes in bull calves. Holstein bull calves were designated to high (HI; n=15) or moderate (MOD; n=15) dietary groups, with diets designed to provoke growth rates of 1.0 and 0.5 kg/day, respectively. At 12 wk of age, all calves were euthanized, and testes parenchyma harvested. RNA was extracted from the testes and used for miRNAseq. Bioinformatic analysis identified 7 miRNA as differentially expressed between the HI and MOD treatment groups, with target mRNA genes invovled in pathways related to AMPK and IGF-1 signaling.
Project description:It has been established that enhanced early life nutrition progresses sexual development in the bull calf through neuroendocrine signalling via the hypothalamic-pituitary-testicular axis. However, the underlying molecular mechanisms regulating this process have not been fully elucidated. This study measured the impact of contrasting feeding regimes in the first 12 wk of life, known to impact age at puberty, on the proteomic landscape of the testes of bull calves. Holstein bull calves with a mean (±SD) bodyweight and age of 48.8 (± 5.3) kg and 17.5 (± 2.8) days, were designated to high (HI; n=10) or moderate (MOD; n=10) dietary groups, with diets designed to provoke growth rates of 1.0 and 0.5 kg/day, respectively. At 12 wk of age, all calves were euthanized, and testes parenchyma harvested. HI calves were heavier at slaughter (112.4 v 88.7 (2.98) kg, P<0.001), and had a greater average daily gain (ADG) of (0.88 v 0.58 kg, P<0.001). The turquoise network from the protein analyses contained the protein CDH13 which is involved in testes development. Gene ontology analysis of the turquoise network revealed enrichment of genes with functions related to cholesterol biosynthesis, IGF-1 signalling, insulin receptor/secretion signalling, androgen signalling and Sertoli cell junction signalling.
Project description:The aim of this study was to investigate the effect of early calf-hood nutrition on the transcriptomic profile of the arcuate nucleus of the hypothalamus, the anterior pituitary and the testes in Holstein-Friesian bulls and possible downstream effects on reproduction. Holstein Friesian bull calves with a mean (±S.D.) age and bodyweight of 19 (±8.2) days and 47.5 (±5.3) kg, respectively, were assigned to either a high (n=10) or low (n=10) plane of nutrition. Calves were fed in order to achieve an overall growth rate of 1.2 and 0.5 kg/day for the high and low plane of nutrition treatments, respectively. At 126 days of age, the bulls were euthanized using an intravenous overdose of sodium pentobarbitone and arcuate nucleus of the hypothalamus, anterior pituitary and the parenchyma of the testes tissue samples were harvested and RNAseq analysis was performed. At the end of the trial period,
Project description:Pre-pubertal Holstein bull calves fed a higher plane of nutrition had larger testes, earlier puberty, higher serum LH, testosterone and greater sperm production potential than those fed a restricted diet. In addition, pre-pubertal calves fed a high-nutrition diet had higher IGF-I and more proliferating and differentiating Sertoli cells much earlier in life, compared to those fed normal or low-nutrition diets. The objective was to determine changes in mRNA expression of genes in the testes of bulls fed either a high or low pre-pubertal diet. Holstein bull calves maintained on either a high (20% crude protein (CP) and 71.6% Total Digestible Nutrients (TDN)) or low (12% CP and 64.4% TDN) diet from 2 wk of age, were castrated at 8, 16, 24 and 32 wk and testicular mRNA extracted and sequenced. Differential expression of genes mainly occurred at 16 and 24 wk, with minor changes detected at 32 wk. At 16 wks, functional analysis of DE mRNA with DAVID revealed the common biological processes enriched to be "cholesterol" and "fatty acid biosynthesis" with majority of the genes including HMGCR, HMGCS1, HSD17 being upregulated in high-diet bulls (P<0.05). Major pathways enriched at 16 wks were "cholesterol biosynthesis", "steroid metabolism" and "activation of gene expression by Sterol regulatory element-binding protein (SREBP)" (P<0.05). Mature Sertoli cell marker Connexin 43, was upregulated at 16 wk, whereas an immature Sertoli cell marker, AMH was downregulated at 24 wk, in the high-diet group. Network analysis using IPA, revealed an indirect interaction between insulin family receptor and most upregulated cholesterol biosynthesis genes, implying regulation of testicular function. Thus, enhanced pre-pubertal nutrition in Holstein bulls enhanced testicular cholesterol/steroid biosynthesis and Sertoli cell maturation to promote early reproductive development.
Project description:The objectives of the study were to use RNA-Seq to examine the effect of (i) breed and (ii) gradual weaning, on the whole blood mRNA transcriptome of artificially reared Holstein-Friesian and Jersey calves. The calves were gradually weaned over 14 days (day (d) -13 to d 0) and mRNA transcription was examined one day before gradual weaning was initiated (d -14), one day after weaning (d 1) and 8 days after weaning (d 8). RNA-seq analysis was carried out on RNA extracted from whole blood. Gradual weaning had no effect on gene expression (P>0.05).There were 550 differentially expressed genes at a false discovery rate of 10% and with a ≥1.5-fold change, between Holstein-Friesian and Jersey calves on d -14, 490 on d 1, and 411 on d 8. GOseq/KEGG pathway analysis showed that the cytokine-cytokine receptor interaction pathway and the neuroactive ligand-receptor interaction pathway were over-represented between breeds on all days (P<0.01; Q≤0.1). These results demonstrate that the gradual weaning practiced here does not compromise the welfare of artificially-reared dairy calves, evidenced by the lack of expression changes in any genes in response to gradual weaning. These data also suggest differences in cell signalling and immune responses between breeds.
Project description:This study evaluated the effect of enhanced dietary intake during the early life period on testes transcriptome in bull calves. Between 2-12 weeks of age bull alves were offered either a high (HI; n=15) or moderate (MOD; n=15) plane of nutrition, with diets designed to evoke growth rates of 1.0 and 0.5 kg/day, respectively. At 12 wk of age, testes parenchyma tissue samples were harvested from all calves and subsequently subjected to mRNAseq. Subsequent bioinformatics analyses revealed differential expression of genes invovled in cellular adhesion and immune function.