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This study was conducted to (i) evaluate the requirement for the administration of GnRH coincident with insertion of a progesterone-releasing intravaginal device (PRID) and (ii) the effect of supplementing with 400 IU eCG at PRID removal on pregnancy per AI (P/AI) in spring and autumn calving suckled beef cows, subjected to a 7-d CO-Synch + PRID timed artificial insemination (TAI) program. Suckled beef cows (n = 1408) on 62 commercial farms were enrolled and randomly assigned to either of three treatments: 1) cows received a PRID and 100 μg GnRH on Day −10, followed by 25 mg PGF2α at PRID removal (Day −3) and 100 μg GnRH 72 h later (Day 0) at TAI (Treatment 1; n: spring = 236, autumn = 248); 2) as Treatment 1, but without GnRH at PRID insertion on Day −10 (Treatment 2; n: spring = 232, autumn = 227); 3) as Treatment 1, but cows also received 400 IU eCG at PRID removal on Day −3 (Treatment 3; n: spring = 233, autumn = 232). At Day −10, ovaries were examined by ultrasonography to evaluate the presence or absence of a corpus luteum (CL) and follicle(s) ≥ 10 mm in diameter. Body condition score (BCS) was assessed on a scale of 1–5. Pregnancy diagnosis was carried out 30–35 d after TAI by transrectal ultrasonography. Data were analyzed using the GENMOD and LOGISTIC procedures of SAS. There was a treatment by season interaction for P/AI (P 0.05) by treatment (50.1 v 53.7 v 48.7% for Treatments 1, 2 and 3, respectively). Overall, eCG had a positive effect on P/AI for cows lacking a CL at treatment initiation (P

Objective With increases in the global population, there is a need to identify strategies that increase beef output while maintaining or improving health benefits of beef products. Studies have demonstrated that there are many benefits to human health in response to reducing the dietary ratio of n-6 to n-3. The aim of this study was to characterize the carcass characteristics and brisket muscle fatty acid profile of young dairy-bred bulls following dietary supplementation with n-6 or n-3 PUFA. Materials and Methods Holstein-Friesian (n = 43) and Jersey (n = 7) bulls with a mean ± SEM age and BW of 420.1 ± 5.86 d and 382.0 ± 8.94 kg, respectively, were offered a cereal-based concentrate diet on an ad libitum basis, fortified with 1 of 3 lipid supplements: control (CTL; no supplementary lipid), n-6 PUFA safflower oil (SO), or n-3 PUFA enriched fish oil (FO). Bulls were individually offered their respective diet for 12 wk before slaughter. Carcass weight, conformation, and fat score were recorded at slaughter for all animals. Brisket muscle was collected from 26 randomly selected bulls, and lipid profile was analyzed using gas chromatography. Results and Discussion Total n-3 PUFA concentration was greater for FO than for either SO or CTL diets (P Implications and Applications Beef producers can feed diets enriched with n-6 and n-3 PUFA, which would result in beef having potential health benefits and greater branding potential.

Adipose tissue represents not only an important energy storage tissue but also a major endocrine organ within the body, influencing many biochemical systems including metabolic status, immune function and energy homeostasis. The objective of this study was to evaluate the effect of an enhanced dietary intake during the early calfhood period on the transcriptome of visceral adipose tissue. Artificially reared Angus × Holstein–Friesian heifer calves were offered either a high (HI, n = 15) or moderate (MOD, n = 15) plane of nutrition from 3 to 21 weeks of life. At 21 weeks of age all calves were euthanized, visceral adipose harvested and samples subsequently subjected to mRNA sequencing. Plane of nutrition resulted in the differential expression of 1214 genes within visceral adipose tissue (adj. p 1.5). Differentially expressed genes were involved in processes related to metabolism and energy production. Biochemical pathways including Sirtuin signalling (adj. p p = 0.009) were also significantly enriched, indicating greater metabolic processing and adipogenesis in the calves on the high plane of nutrition. Results from this study identify novel genes regulating the molecular response of visceral adipose tissue to an improved plane of nutrition during early calfhood.

Cellular mitochondrial function has been suggested to contribute to variation in feed efficiency (FE) among animals. The objective of this study was to determine mitochondrial abundance and activities of various mitochondrial respiratory chain complexes (complex I (CI) to complex IV (CIV)) in liver and muscle tissue from beef cattle phenotypically divergent for residual feed intake (RFI), a measure of FE. Individual DM intake (DMI) and growth were measured in purebred Simmental heifers (n = 24) and bulls (n = 28) with an initial mean BW (SD) of 372 kg (39.6) and 387 kg (50.6), respectively. All animals were offered concentrates ad libitum and 3 kg of grass silage daily, and feed intake was recorded for 70 days. Residuals of the regression of DMI on average daily gain (ADG), mid-test BW0.75 and backfat (BF), using all animals, were used to compute individual RFI coefficients. Animals were ranked within sex, by RFI into high (inefficient; top third of the population), medium (middle third of population) and low (efficient; bottom third of the population) terciles. Statistical analysis was carried out using the MIXED procedure of SAS v 9.3. Overall mean ADG (SD) and daily DMI (SD) for heifers were 1.2 (0.4) and 9.1 (0.5) kg, respectively, and for bulls were 1.8 (0.3) and 9.5 (1.02) kg, respectively. Heifers and bulls ranked as high RFI consumed 10% and 15% more (P < 0.05), respectively, than their low RFI counterparts. There was no effect of RFI on mitochondrial abundance in either liver or muscle (P > 0.05). An RFI × sex interaction was apparent for CI activity in muscle. High RFI animals had an increased activity (P < 0.05) of CIV in liver tissue compared to their low RFI counterparts; however, the relevance of that observation is not clear. Our data provide no clear evidence that cellular mitochondrial function within either skeletal muscle or hepatic tissue has an appreciable contributory role to overall variation in FE among beef cattle.

The selection of cattle with enhanced feed efficiency is of importance with regard to reducing feed costs in the beef industry. Global transcriptome profiling was undertaken on liver and skeletal muscle biopsies from Simmental heifers and bulls divergent for residual feed intake (RFI), a widely acknowledged feed efficiency phenotype, in order to identify genes that may be associated with this trait. We identified 5 genes (adj. p

In vitro methods of assessing bull semen quality in artificial insemination (AI) centers are unable to consistently detect individuals of lower fertility, and attempts to reliably predict bull fertility are still ongoing. This highlights the need to identify robust biomarkers that can be readily measured in a practical setting and used to improve current predictions of bull fertility. In this study, we comprehensively analyzed a range of functional, morphological, and intracellular attributes in cryopreserved spermatozoa from a selected cohort of Holstein Friesian AI bulls classified as having either high or low fertility (n = 10 of each fertility phenotype; difference of 11.4% in adjusted pregnancy rate between groups). Here, spermatozoa were assessed for motility and kinematic parameters, morphology, acrosome integrity, plasma membrane lipid packing, viability (or membrane integrity), superoxide production, and DNA integrity. In addition, spermatozoa were used for in vitro fertilization to evaluate their capacity for fertilization and successful embryo development. The information collected from these assessments was then used to phenotypically profile the 2 groups of bulls of divergent fertility status as well as to develop a model to predict bull fertility. According to the results, acrosome integrity and viability were the only sperm attributes that were significantly different between high- and low-fertility bulls. Interestingly, although spermatozoa from low-fertility bulls, on average, had reduced viability and acrosome integrity, this response varied considerably from bull to bull. Principal component analysis revealed a sperm phenotypic profile that represented a high proportion of ejaculates from low-fertility bulls. This was constructed based on the collective influence of several sperm attributes, including the presence of cytoplasmic droplets and superoxide production. Finally, using the combined results as a basis for modeling, we developed a linear model that was able to explain 47% of the variation in bull field fertility in addition to a logistic predictive model that had a 90% chance of distinguishing between fertility groups. Taken together, we conclude that viability and acrosome integrity could serve as fertility biomarkers in the field and, when used alongside other sperm attributes, may be useful in detecting low-fertility bulls. However, the variable nature of low-fertility bulls suggests that additional, in-depth characterization of spermatozoa at a molecular level is required to further understand the etiology of low fertility in dairy bulls.

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) d 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/d, respectively. Throughout the trial, animal growth performance, feed intake, and systemic concentrations of metabolites, metabolic hormones, and reproductive hormones were assessed. Additionally, pulsatility of reproductive hormones (luteinizing hormone, follicle-stimulating hormone, and testosterone) was recorded at 15-min intervals during a 10-h period at 10 wk of age. At 87 ± 2.14 d of age, all calves were euthanized, testes were weighed, and testicular tissue was harvested. Differential expression of messenger ribonucleic acid (mRNA) candidate genes involved in testicular development was examined using quantitative polymerase chain reaction assays. All data were analyzed using the MIXED procedure in Statistical Analysis Software 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 HI plane of nutrition though the concentrations of reproductive hormones were not affected by diet. Calves on the HI diet had greater mean (SED) slaughter weight (112.4 vs. 87.70 [2.98] kg; P < 0.0001) and testicular tissue weight (29.2 vs. 20.1 [2.21] g; P = 0.0003) than those on the MOD diet. Relative mRNA abundance data indicated advanced testicular development through upregulation 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 3 mo of life not only improves growth performance and metabolic status but also advances testicular development consistent with more precocious sexual maturation.

Aberdeen Angus calves were sacrificed from immediately post-birth up to 96 days of age (DOA) and ileal samples were collected for microbial, histological and immunological analyses. Firmicutes bacteria were established immediately in the ileum of calves after birth and remained the dominant phyla at all time points from birth until 96 DOA. Temporal shifts in phyla reflected significantly increased Bacteroidetes at birth followed by temporal increases in Actinobacteria abundance over time. At a cellular level, a significant increase in cell density was detected in the ileal villi over time. The innate cell compartment at birth was composed primarily of eosinophils and macrophages with a low proportion of adaptive T lymphocytes; whereas an increase in the relative abundance of T cells (including those in the intra-epithelial layer) was observed over time. The ileal intestinal cells were immunologically competent as assessed by expression levels of genes encoding the inflammasome sensor NLRP3, and inflammatory cytokines IL1A, IL1B and IL33—all of which significantly increased from birth. In contrast, a temporal reduction in genes encoding anti-inflammatory cytokine IL10 was detected from birth. This study provides an integrated baseline of microbiological, histological and immunological data on the immune adaptation of the neonatal ileum to microbial colonisation in calves.

Despite passing routine laboratory tests of semen quality, bulls used in artificial insemination (AI) exhibit a significant range in field fertility. The objective of this study was to determine whether subfertility in AI bulls is due to issues of sperm transport to the site of fertilization, fertilization failure, or failure of early embryo or conceptus development. In experiment 1, Holstein-Friesian bulls (3 high fertility, HF, and 3 low fertility, LF) were selected from the national population of AI bulls based on adjusted fertility scores from a minimum of 500 inseminations (HF: +4.37% and LF: -12.7%; mean = 0%). Superovulated beef heifers were blocked based on estimated number of follicles at the time of AI and inseminated with semen from HF or LF bulls (n = 3-4 heifers per bull; total 19 heifers). Following slaughter 7 d later, the number of corpora lutea was counted and the uteri were flushed. Recovered structures (oocytes/embryos) were classified according to developmental stage and stained with 4',6-diamidino-2-phenylindole to assess number of cells and accessory sperm. Overall recovery rate (total structures recovered/total corpora lutea) was 52.6% and was not different between groups. Mean (± standard error of the mean) number of embryos recovered per recipient was 8.7 ± 5.2 and 9.4 ± 5.5 for HF and LF, respectively. Overall fertilization rate of recovered structures was not different between groups. However, more embryos were at advanced stages of development (all blastocyst stages combined), reflected in a greater mean embryo cell number on d 7 for HF versus LF bulls. Number of accessory sperm was greater for embryos derived from HF than for LF bulls. The aim of experiment 2 was to evaluate the effect of sire fertility on survival of bovine embryos to d 15. Day 7 blastocysts were produced in vitro using semen from the same HF (n = 3) and LF (n = 3) bulls and transferred in groups of 5-10 to synchronized heifers (n = 7 heifers per bull; total 42 heifers). Conceptus recovery rate on d 15 was higher in HF (59.4%,) versus LF (45.0%). Mean length of recovered conceptuses for HF bulls was not affected by fertility status. In conclusion, while differences in field fertility among AI sires used in this study were not reflected in fertilization rate, differences in embryo quality were apparent as early as d 7. These differences likely contributed to the higher proportion of conceptuses surviving to d 15 in HF bulls.

The aim was to examine the effect of rapid body weight gain during early calfhood consistent with earlier sexual development on the transcriptional profile of the hypothalamus. Angus X Holstein-Friesian heifer calves (19 ± 5 days of age) were offered a high (HI, n = 14) or moderate (MOD, n = 15) plane of nutrition from 3 to 21 weeks of age to achieve a growth rate of 1.2 kg/d and 0.5 kg/d, respectively. Following euthanasia at 21 weeks, the arcuate nucleus (ARC) region was separated from the remainder of the hypothalamus and both were subjected to RNA-Seq. HI calves exhibited altered expression of 80 and 39 transcripts in the ARC and the remaining hypothalamus, respectively (P, The authors would like to acknowledge all skilled technical assistance and support from the Farm Manager and Farm Staf from Teagasc, Grange Beef Research Centre (Dunsany, Co. Meath, Ireland) during the course it this study. Tis research was funded by the Department of Agriculture, Food & Marine, Ireland through the Research Stimulus Fund (13/S/515)

This study examined the effect of plane of nutrition on the endocrinological regulation of the hypothalamic–pituitary–ovarian (HPO) axis in beef heifer calves during a critical sexual developmental window early in calf hood. Forty Holstein-Friesian × Angus heifers (mean age 19 d, SEM = 0.63) were assigned to a high (HI; ADG 1.2 kg) or moderate (MOD; ADG 0.50 kg) nutritional level from 3 to 21 wk of life. Intake was recorded using an electronic calf feeding system, BW was recorded weekly, and blood samples were collected on the week of age 5, 10, 15, and 20 for metabolite, reproductive, and metabolic hormone determination. At 19 wk of age, on sequential days, an 8-h window bleed was carried out for luteinizing hormone (LH), follicle-stimulating hormone (FSH), and estradiol analysis. To characterize anterior pituitary gland function, an intravenous GnRH challenge was conducted (19 wk of age). Blood was collected via a jugular catheter every 15 min for 135 min for the analysis of LH, FSH, and estradiol. Calves were subsequently euthanized at 21 wk of age; the anterior pituitary, metabolic organs, and reproductive tract were weighed, and ovarian surface follicular numbers and oocytes recovered were recorded. Mean ADG was 1.18 and 0.50 kg for HI and MOD, respectively, resulting in a 76.6-kg difference in BW (P < 0.001). Blood insulin, glucose, and IGF-1 concentrations were greater (P < 0.001) for HI compared with MOD. There was a diet × time interaction for leptin (P < 0.01); concentrations were greater in HI compared with MOD at 20 wk of age with no difference between treatments before this. Dietary treatment did not alter the concentrations of adiponectin or anti-mullerian hormone. There was a diet × time interaction for FSH, whereby MOD had greater concentrations than HI at 10, 15, and 20, but not at 5 wk of age. Over the duration of an 8-h window bleed (19 wk of age), serum concentrations of LH, LH pulse frequency, and LH pulse amplitude were unaffected by treatment, whereas FSH (0.23 vs. 0.43 ng/mL) and estradiol (0.53 vs. 0.38 ng/mL) concentrations were less than and greater, respectively, for HI than MOD (P < 0.05). Likewise, following a GnRH challenge, the area under the curve analysis revealed greater (P < 0.01) estradiol and lesser (P < 0.01) FSH concentrations in calves on the HI relative to MOD diet, whereas concentrations of LH were unaffected (P = 0.26) between treatments. Ovarian surface follicle numbers were greater (P < 0.05) in HI compared with MOD. Total reproductive tract, uterus, and ovarian tissue expressed relative to BW were greater (P < 0.05) for HI compared with MOD. In conclusion, enhanced nutrition in early calfhood advances the ontogeny development of the HPO axis.

peer-reviewed In humans and model species, alterations of sperm DNA methylation patterns have been reported in cases of spermatogenesis defects, male infertility and exposure to toxins or nutritional challenges, suggesting that a memory of environmental or physiological changes is recorded in the sperm methylome. The objective of this study was to ascertain if early life plane of nutrition could have a latent effect on DNA methylation patterns in sperm produced post-puberty. Holstein-Friesian calves were assigned to either a high (H) or moderate (M) plane of nutrition for the first 24 weeks of age, then reassigned to the M diet until puberty, resulting in HM and MM groups. Sperm DNA methylation patterns from contrasted subgroups of bulls in the HM (ejaculates recovered at 15 months of age; n = 9) and in the MM (15 and 16 months of age; n = 7 and 9, respectively) were obtained using Reduced Representation Bisulfite Sequencing. Both 15 and 16 months were selected in the MM treatment as these bulls reached puberty approximately 1 month after the HM bulls. Hierarchical clustering demonstrated that inter-individual variability unrelated to diet or age dominated DNA methylation profiles. While the comparison between 15 and 16 months# of age revealed almost no change, 580 differentially methylated CpGs (DMCs) were identified between the HM and MM groups. Differentially methylated CpGs were mostly hypermethylated in the HM group, and enriched in endogenous retrotransposons, introns, intergenic regions, and shores and shelves of CpG islands. Furthermore, genes involved in spermatogenesis, Sertoli cell function, and the hypothalamic–pituitary–gonadal axis were targeted by differential methylation when HM and MM groups were compared at 15 months of age, reflecting the earlier timing of puberty onset in the HM bulls. In contrast, the genes still differentially methylated in MM bulls at 16 months of age were enriched for ATP-binding molecular function, suggesting that changes to the sperm methylome could persist even after the HM and MM bulls reached a similar level of sexual maturity. Together, results demonstrate that enhanced plane of nutrition in pre-pubertal calves associated with advanced puberty induced modest but persistent changes in sperm DNA methylation profiles after puberty.

Les dades d’expressió gènica estan disponibles públicament al repositori digital Dryad https://doi.org/10.5061/dryad.s7h44j14r i al repositori institucional DUGiDocs http://hdl.handle.net/10256/18379 An appropriate female reproductive environment is essential for pregnancy success. In several species, including mice, pigs and horses, seminal plasma (SP) components have been shown to modulate this environment, leading to increased embryo viability and implantation. Due to the characteristics of mating in the aforementioned species, SP comes into direct contact with the uterus. However, it is questionable whether any SP reaches the uterus in species that ejaculate inside the vagina, such as humans and cattle. Hence, we hypothesized that sperm, perhaps acting as a vehicle for SP factors, play a more important role in the modulation of the maternal uterine environment in these species. In addition, changes elicited by SP and/or sperm may originate in the vagina and propagate to more distal regions of the female reproductive tract. To test these hypotheses, a bovine model in which heifers were mated to intact or vasectomized bulls or were left unmated was used. RNA-sequencing of endometrial samples collected 24 h after mating with a vasectomized bull did not reveal any differentially expressed genes (DEGs) in comparison with control samples. However, the endometrium of heifers mated with intact bulls exhibited 24 DEGs when compared to heifers mated with vasectomized bulls, and 22 DEGs when compared to unmated control heifers. The expression of a set of cytokines (IL6, IL1A, IL8, and TNFA) and candidate genes identified in the endometrial RNA-sequencing (PLA2G10, CX3CL1, C4BPA, PRSS2, BLA-DQB, and CEBPD) were assessed by RT-qPCR in the vagina and oviductal ampulla. No differences in expression of these genes were observed between treatments in any region. However, mating to both intact and vasectomized bulls induced an increase in IL1A and TNFA expression in the vagina compared to the oviduct. These data indicate that sperm, but not secretions from the accessory glands alone, induce modest changes in endometrial gene expression after natural mating in cattle. However, it is not clear whether this effect is triggered by inherent sperm proteins or SP proteins bound to sperm surface at the time of ejaculation This work was funded by the EU Horizon 2020 Marie Skłodowska-Curie (No. 792212) and Science Foundation Ireland (Grant No. 16/IA/4474)

A growing body of evidence suggests that paternal factors have an impact on offspring development. These studies have been mainly carried out in mice, where seminal plasma (SP) has been shown to regulate endometrial gene expression and impact embryo development and subsequent offspring health. In cattle, infusion of SP into the uterus also induces changes in endometrial gene expression, however, evidence for an effect of SP on early embryo development is lacking. In addition, during natural mating, the bull ejaculates in the vagina; hence, it is not clear whether any SP reaches the uterus in this species. Thus, the aim of the present study was to determine whether SP exposure leads to improved early embryo survival and developmental rates in cattle. To this end, Day 7 in vitro produced blastocysts were transferred to heifers (12-15 per heifer) previously mated to vasectomized bulls (n = 13 heifers) or left unmated (n = 12 heifers; control). At Day 14, heifers were slaughtered, and conceptuses were recovered to assess size, morphology and expression of candidate genes involved in different developmental pathways. Additionally, CL volume at Day 7, and weight and volume of CL at Day 14 were recorded. No effect of SP on CL volume and weight not on conceptus recovery rate was observed. However, filamentous conceptuses recovered from SP-exposed heifers were longer in comparison to the control group and differed in expression of CALM1, CITED1, DLD, HNRNPDL, PTGS2, and TGFB3. In conclusion, data indicate that female exposure to SP during natural mating can affect conceptus development in cattle. This is probably achieved through modulation of the female reproductive environment at the time of mating This work was supported by the European Union’s Horizon 2020 Research and Innovation Program (Grant Agreement No. 792212) and Science Foundation Ireland (Grant No. 16/IA/4474)

The advent of genomic selection has accentuated interest in procuring saleable semen from young genetically elite bulls as early in life as possible. However, the timing of availability of semen for commercial use will be determined by the age at which these young animals reach puberty and subsequent sexual maturity. Enhancing early-life nutrition stimulates the functionality of the hypothalamic–pituitary–testicular axis, mediated through complex biochemical interplay between metabolic and neuroendocrine signals and culminating in enhanced testicular growth, steroidogenesis, spermatogenesis, and ultimately, earlier onset of sexual maturation. Indeed, recent evidence indicates that the timing of sexual precocity, which is dictated by an early gonadotropin rise (8–20 wk of age) in the bull, is determined by prevailing metabolic status during calfhood and is not compensable even where prior undernutrition is followed by dietary augmentation. However, despite this, the precise neuronal mechanisms regulating these developmental processes remain to be elucidated for the bull. Although early-life nutrition clearly affects the sexual maturation process, there is little evidence for latent effects on postpubertal semen characteristics. Equally, postpubertal fertility, measured as in vitro fertilization and early embryogenesis, is not influenced by nutritional status during early life. Current efforts employing high throughput nucleic acid and proteomic sequencing and targeted immunofluorescence coupled with systems biology–based gene network analyses can provide further insight on how nutrition may mediate the biochemical interaction between neuroendocrine and testicular cellular processes. Such information can be harnessed to identify potential genomic targets as part of genomically assisted breeding programs as well as facilitate development of strategic nutritional regimens to optimize sexual maturation and subsequent semen availability from genetically elite young bulls.

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, anterior pituitary and testes in Holstein-Friesian bulls. 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 offered a high (n = 10) or low (n = 10) plane of nutrition in order to achieve an overall growth rate of 1.2 and 0.5 kg/day. At 126 (±3) days of age, calves were euthanized, hypothalamus (arcuate region), anterior pituitary and testicular parenchyma samples were harvested and RNAseq analysis was performed. There were 0, 49 and 1,346 genes differentially expressed in the arcuate nucleus, anterior pituitary and testicular tissue of bull calves on the low relative to the high plane of nutrition, respectively (P

The effect of feed restriction (99 days) followed by compensatory growth during a 200 day re-alimentation period on the colour and sensory characteristics of meat from Aberdeen Angus × Holstein-Friesian (AN) and Belgian Blue × Holstein-Friesian (BB) steers was examined. Compensatory growth had no effect on muscle pH and temperature decline, chemical composition, drip loss, fat colour, or juiciness, but increased (P = 0.009) Warner-Bratzler shear force and decreased tenderness (P = 0.08) and overall liking (P = 0.09). Compared to meat from BB steers, meat from AN steers had a higher intramuscular fat concentration and was rated similarly for tenderness, but higher for many of the flavour characteristics examined. While adjustment for intramuscular fat concentration removed some of these differences, genotype-specific flavour differences remained. It is concluded that genotype had greater effects on meat quality than the compensatory growth feeding regime imposed in this study.

Improved nutrition and metabolic status during early life are known to advance sexual development in the bull calf. This is mediated through complex neuroendocrine signaling at the level of the hypothalamic-pituitary-testicular (HPT) axis resulting in precocious testicular development and spermatogenesis. The arcuate nucleus region (ARC) of the hypothalamus is centrally involved in the integration of peripheral metabolic cues with GnRH neuronal function and gonadotropin pulsatility which in turn stimulate testicular development. However, the precise molecular mechanisms regulating the influence of prevailing nutritional status on hypothalamic function are yet to be fully elucidated. The objective of this study was to evaluate differentially expressed genes (DEG) within the ARC of bull calves offered contrasting planes of nutrition during the first 12 weeks of life, to coincide with the characteristic transient gonadotropin rise. Holstein-Friesian bull calves with a mean (+SD) bodyweight and age of 48.8(5.3) kg and 17.5(2.8) days, respectively, were assigned to either a high energy (H; n = 15) or moderate energy (M; n = 15) plane of nutrition designed for growth rates of 1.0 and 0.5 kg/day, respectively. At 12 weeks of age all calves were euthanized and the ARC harvested. RNA was isolated from all ARC samples and RNAseq analysis conducted. As expected, H calves were heavier at euthanasia (H=112 kg; M=88 kg, P < 0.001). RNAseq analysis resulted in the identification of 83 DEG (P.adj< 0.1; fold change >1.5), all of which were down-regulated in H compared to M calves. DEG were enriched for biological pathways associated with immune function including complement system and acute phase response signaling (P.adj< 0.01). However, no DEG identified were directly involved in reproductive developmental processes. Results from this study suggest that the typically positive effect of enhanced nutrition on reproductive development may not be apparent within the ARC at 12 weeks of age.

Supplementation of cattle diets with n-3-polyunsaturated fatty acids (PUFA) can improve reproductive efficiency. Conversely, short-term fluctuations in feed supply can impact pregnancy establishment. The objectives of this study were to examine the effects of (1) dietary supplementation with n-3-PUFA and (2) post-insemination plane of nutrition on the endometrial transcriptome. Beef crossbred heifers were offered concentrate based diets fortified with n-3-PUFA (PUFA; n = 32) or not (CONT; n = 28) for 30 days prior to breeding at a synchronised oestrous. Following artificial insemination, heifers were allocated within treatment to either a high or low plane of nutrition. Heifers were maintained on these diets for 16 days following which endometrial tissue was harvested at slaughter for subsequent RNAseq analysis. The influence of pregnancy status on the endomentrial transcriptome, within each dietary treatment group, was also examined. Post-insemination diet affected (P n-3-PUFA-supplemented heifers, genes involved in embryonic development and mTOR signalling pathways, important in pregnancy establishment, were identified as differentially expressed. Results indicate that dietary supplementation of cattle diets with n-3-PUFA may have a positive effect on the expression of key fertility-related genes and pathways, during the critical window of maternal recognition of pregnancy, particularly where animals are underfed.

peer-reviewed Leydig cell functional capacity reflects the numbers and differentiation status of the steroidogenic Leydig cells in the testes and becomes more or less fixed in early adulthood with the final establishment of the hypothalamo-pituitary-gonadal (HPG) axis after puberty. Factors influencing Leydig cell functional capacity and its role in puberty are poorly understood. Using a bovine model of dairy bulls fed four different nutritional regimes from 1 month to 12 months, and applying circulating Insulin-like peptide 3 (INSL3) as an accurate biomarker of Leydig cell functional capacity, showed that a high plane of nutrition in the first 6 months of life, but not later, significantly increased INSL3 in young adulthood. Moreover, INSL3 concentration at 4 months indicated a marked differential in early feeding regime and correlated well (negatively) with the timing of puberty, as reflected by the age in days for the first production of an ejaculate with >50 million sperm and >10% forward motility, as well as with testis size at 18 months. Reversing the diet at 6 months was unable to rectify the trend in either parameter, unlike for other parameters such as testosterone, body weight, and scrotal circumference. This study has shown that early prepubertal nutrition is a key factor in the development of Leydig cell functional capacity in early adulthood and appears to be a key driver in the dynamic progression of puberty.

Early onset of puberty is a key trait underpinning economically efficient cattle production systems. Although prepubertal plane of nutrition has been positively associated with earlier onset of puberty, the underlying biochemical mechanisms remain unknown. The hypothalamus, and particularly the arcuate nucleus (ARC), has a pivotal role during this developmental stage because it is a central regulator of homeostasis, mediating various neuroendocrine and physiological functions, including feed intake and reproduction. Thus, we hypothesised that a high plane of nutrition during early calfhood would affect the transcriptional profile of hypothalamic tissue, and in particular, elicit differential expression of biochemical pathways consistent with earlier sexual development in beef heifers. Angus×Holstein-Friesian heifer calves (19±5 days of age, 51.2±7.8kg, mean±s.d.) were offered a high (HP, n=14) or moderate plane of nutrition (MP, n=15) from 3 to 21 weeks of age to achieve target growth rates of 1.2 and 0.5 kg/d, respectively. At 21 weeks of age, calves were killed and the brain recovered. The ARC region was separated from the remainder of the hypothalamus, with both tissues flash frozen and subsequently used for RNA sequencing. Differential expression of genes (DEGs) was determining using R Bioconductor package EdgeR (version 3.20.9). The resultant list of DEGs was then submitted to Ingenuity Pathway Analysis and Weighted Gene Co-expression Network Analysis (WGCNA). At slaughter, bodyweight was higher in HP calves (189.6 vs. 113.0 kg; P

The objectives of this study were (i) to characterise clinical health in dairy calves on an Irish research farm during the artificial calf-rearing period and (ii) to determine whether calves’ pre-weaning intakes and feeding behaviour, recorded by electronic calf feeders, changes in response to incidents of bovine respiratory disease (BRD). Holstein-Friesian (H-F) and Jersey (J) calves were fed by automatic milk replacer (MR) and concentrate feeders. Feeding behaviour, including MR consumption, drinking speed, number of rewarded and unrewarded visits to the feeder as well as concentrate consumption, was recorded by the feeders. A modified version of the Wisconsin calf health scoring criteria chart was used to score calves’ clinical measurements and identify incidences of BRD. Thus, 40% of calves were found to have at least one incident of BRD. Feeding behaviour was altered during incidents of BRD. The number of unrewarded visits to the feeder was reduced, by approximately four visits, for calves with BRD during the 3 d prior to the identification of BRD(P< 0.05) and tended to be reduced during the 7 d following the identification of BRD(P= 0.05), compared with healthy calves. Additionally, calves with BRD had a tendency for reduced net energy intake (approximately 8%) during the 3 d prior to the identification of BRD, compared with healthy calves. Therefore, calf feeding behavioural data, recorded by electronic feeders during the pre-weaning period, can indicate cases of BRD.

The objective of this study was to determine if beef heifers divergently ranked on phenotypic residual feed intake (RFI) differed in their physiological stress response to an exogenous bovine corticotropin-releasing hormone (bCRH) challenge. Yearling Limousin × Friesian heifers ( = 86) were ranked by RFI. The 15 highest (mean 0.66 kg DM/d; high RFI) and 15 lowest (mean -0.72 kg DM/d; low RFI) ranking animals were used for this study. During the study period, heifers (mean age 485 ± 13 d; mean BW 408 ± 31.4 kg) were housed in a slatted-floor facility. To facilitate intensive blood collection, heifers were fitted aseptically with indwelling jugular catheters. All heifers received dexamethasone (DEX; 20 µg/kg BW i.m.) 12 h before the bCRH challenge (d 0). Heparinized blood samples were collected at -60 and 0 min before administration of DEX, and 12 h after DEX administration. Following DEX administration, cortisol and dehydroepiandrosterone (DHEA) concentrations similarly decreased ( ≥ 0.22) between high and low RFI groups. The response of the HPA axis to a standardized dose of bCRH (0.3 μg/kg BW) was examined. On d 0, serial blood samples were collected at -20, 0, 20, 40, 60, 80, 100, 120, 150, 180, 210, 240, 270, 330, and 390 min relative to the time of bCRH administration (0 min) and were analyzed for plasma cortisol and DHEA concentrations. Blood hematology variables were also determined at -20, 0, 20, 80, 150, 270, 330, and 390 min relative to bCRH administration. Neither an RFI × sampling time interaction nor a direct effect of RFI were detected ( ≥ 0.36) for plasma cortisol, DHEA concentrations, or cortisol:DHEA ratio. An effect of sample time was observed for cortisol ( < 0.001), DHEA ( = 0.04), and cortisol:DHEA ( = 0.02), with cortisol concentration peaking at 60 min post-CRH administration. The maximum concentration and rate of change in cortisol and DHEA concentrations following bCRH administration were not different ( ≥ 0.20) between the high and low RFI phenotypes. Similarly, an effect of RFI was not evident ( ≥ 0.16) for any of the hematology variables examined including neutrophil, lymphocyte, and leukocytes counts; white and red blood cell numbers; and hemoglobin concentrations. Our results suggest that responsiveness of the HPA to stress, at least at the level of the anterior pituitary gland, is not a significant contributor to variation in RFI among growing beef heifers.

Exercise in horses induces neutrophil degranulation and subsequent increases in plasma myeloperoxidase concentrations (MPO). It is not known whether this response is affected by training or the sampling time in relation to exercise. Our objective was to evaluate plasma MPO concentration at different time points in response to exercise in Thoroughbreds before and following high-intensity training and to evaluate relationships between plasma MPO concentration, physiological measurements and performance. Throughbred racehorses in active training and racing (n=26) performed an exercise test on a high-speed treadmill at least once at the beginning (first three months), middle (second three months) or end (last three months) of a nine month training period with training intensity (number of fast work sessions) collated for each period. Heart rate, speed and distance were recorded and venous blood collected before (T0), during and up to maximal speed (TVmax), 5 min (T5min) and 4 h (T4h) following exercise for measurement of plasma lactate, serum creatine kinase concentration, plasma MPO concentration, white blood count (WBC), neutrophil count (Neut), lymphocyte count and neutrophil percentage (%Neut). WBC increased above T0 values at all sampling points with no training effect. Neut and %Neut increased above T0 values at T4h, while values at TVmax, T5min and T4h increased as training duration increased. Plasma MPO concentration increased above T0 values at all sampling points in response to exercise with all values increasing as training duration increased. Training intensity did not affect any of the measurements, correlations were not identified between any of the biological markers including MPO and physiological and training measurements and no differences were identified between elite versus non-elite horses. It was concluded that plasma MPO concentration is affected by exercise and training duration, and that further investigation of plasma MPO as an assessor of fitness and readiness for competition is warranted.

Haematological profiles indicate the health status of an animal and can be used to identify sub-clinical stress responses. The objectives of the study were to examine (i) the effect of breed and plane of nutrition, on haematological profiles of artificially reared Holstein-Friesian and Jersey bull calves in response to gradual weaning, and (ii) the effect of breed on immune response genes in bovine whole blood using real-time quantitative PCR. Holstein-Friesian and Jersey bull calves were group housed indoors and individually fed using an automatic feeder. They were allocated to a high, medium or low plane of nutrition, based on milk replacer (MR) and concentrate. The nutrition treatments were calculated using National Research Council guidelines in order to achieve a high, medium or low growth rate for each respective breed. During the weaning phase MR was gradually reduced over a 14-day (d) period (d −13 to d 0). Calves were blood sampled on d −14, −6, −3, 0, 1, 3, 8 and 14 relative to weaning (d 0) for subsequent haematological analysis. On d −14, 1 and 8, a subset of eight Holstein-Friesian calves randomly selected from the medium nutrition treatment and eight Jersey calves randomly selected from the high nutrition treatment, were blood sampled for gene expression profiling, targeting biomarkers of weaning stress. These two treatment groups were chosen to examine the effect of breed on expression of the genes of interest, as energy intake and animal performance were similar. There was no effect of breed×plane of nutrition interaction nor effect of plane of nutrition on any variable measured (P>0.05). Gradual weaning produced differential biological responses in the two breeds evidenced by breed×time interactions for lymphocyte, monocyte and red blood cell number, plasma haemoglobin and haptoglobin concentrations (P

peer-reviewed Nutrition, and particularly dietary energy intake, plays a fundamental role in reproductive function in cattle. There is some evidence that supplemental omega-3 dietary polyunsaturated fatty acids (n-3 PUFA) can exert positive effects on fertility. The objectives of this study were to evaluate the effect of dietary n-3 PUFA supplementation, post-insemination energy plane of nutrition and their interaction on embryo survival in cattle. Crossbred beef heifers (n = 185) were individually offered barley straw ad libitum and 6 kg DM of concentrate supplemented with either a rumen-protected source of saturated fatty acid (palmitic; control, CON) or a partially rumen-protected n-3 PUFA-enriched supplement (n-3 PUFA). Estrous was synchronised using two injections of PG administered at 11-d intervals and following artificial insemination (AI = Day 0) 179 heifers exhibiting oestrus were inseminated and assigned to one of two dietary treatments: (i) remain on their pre-insemination high dietary plane of nutrition (High) or (ii) restricted to 0.6 × estimated maintenance energy requirements (Low) in a 2 × 2 factorial design. The heifers were then maintained on their assigned diets until slaughter and embryo recovery on Day 16 (n = 92) or pregnancy diagnosis by ultrasound scanning at Day 30 post-AI (n = 87). Plasma concentrations of fatty acids, metabolites, insulin, progesterone (P4) and insulin-like growth factor 1 (IGF-1) were measured at appropriate intervals. Hepatic expression of mRNA for aldo-keto reductase (AKR1C), cytochrome P450 2C (CYP 2C) and cytochrome P450 3A (CYP 3A) was examined. The n-3 PUFA supplementation increased plasma n-3 PUFA concentration (P

The objective of this study was to identify transcriptional variants in key genes involved in compensatory growth (CG) in cattle. Fifteen Holstein-Friesian bulls were offered a restricted diet (growing at 0.6kg/day) for 125 days (Period 1) followed by ad libitum access to feed for a further 55 days (Period 2), during which they displayed CG. A control group received ad libitum access to feed across both periods. Following 55 days of ad libitum feeding and CG, tissue samples including liver, rumen papillae and jejunal epithelium were sampled from all animals. RNAseq was performed on tissue samples and transcriptional variants were subsequently called from resultant sequencing data as per the GATK guidelines. The Ensembl Variant Effect Predictor program was then used for annotation of identified variants. The bulls displayed CG during Period 2 growing at 1.8 times that rate of the control group. Of the key genes examined (n=53), 1854 transcript variants were identified in cattle undergoing CG. Of the variants identified, 69% were synonymous, 29% were missense, 1% were frameshift variants while 1% were inframe deletions. Four genes contained high impact variants in the liver, namely: CYP51A1, SEMA4B, ACSM1 and ELN. CYP51A1 and SEMA4B which are involved in cholesterol synthesis and receptor activity respectively contained frameshift variants. Two splicing variants were also present in liver; ACSM1, which is involved in GTP binding and ELN which encodes a major structural protein. These same high impact variants were also evident during CG within the rumen; CYP51A1, SEMA4B and ELN and in the jejunum ELN was also classified as a high impact variant. Transcriptional variants identified in the current study may, following validation, may hold potential for use as DNA based biomarkers for the selection of cattle with a superior ability to undergo CG following dietary restriction.

peer-reviewed In the original publication of this article [1], some errors in Table 4 need to be corrected as below

Enrichment of calf diets with exogenous butyrate has shown promise as a promotor of calf growth and intestinal development. However, the impact of dietary derived butyrate on the gut microbiota and their potential role, in turn, as mediators of its effect on calf growth and development is not known. Here, the effects of butyrate supplementation on rumen and hindgut microbiota and fermentation profiles were assessed in 16 Holstein-Friesian bull calves randomly assigned to one of two groups: Control (CON) fed conventional milk replacer or Sodium-Butyrate (SB – added to milk replacer) from days 7 to 56 of life. In the colon, total short chain fatty acid (SCFA), propionate and acetate concentrations were increased by SB (P Butyrivibrio and Shuttleworthia were decreased by SB (P Phascolarctobacterium was higher (P Mogibacterium is associated with impaired gut health and was reduced in the cecum of SB calves (P

The objective of this study was to examine the effect of nutrition during the first 18 weeks of life on the physiological and transcriptional functionality of the hypothalamic (arcuate nucleus region), anterior pituitary and testes in Holstein–Friesian bull calves. 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, to achieve an overall target growth rate of 1.2 or 0.5 kg/day, respectively. At 126 ± 1.1 days of age, all calves were euthanised. Animal performance (weekly) and systemic concentrations of metabolic (monthly) and reproductive hormones (fortnightly) were assessed. Testicular histology, targeted gene and protein expression of the arcuate nucleus region, anterior pituitary and testes were also assessed using qPCR and immunohistochemistry, respectively. The expression of candidate genes in testicular tissue from post pubertal 19-month-old Holstein–Friesian bulls (n = 10) was compared to that of the 18-week-old calves. Metabolite and metabolic hormone profiles generally reflected the improved metabolic status of the calves on the HIGH (P< 0.001). Calves offered a HIGH plane of nutrition were heavier at slaughter (P < 0.001), had larger testes (P < 0.001), larger seminiferous tubule diameter (P < 0.001), more mature spermatogenic cells (P < 0.001) and more Sertoli cells (P < 0.05) in accordance with both morphological and transcriptional data. Overall, testicular gene expression profiles suggested a more mature stage of development in HIGH compared with LOW and were more closely aligned to that of mature bulls. Ghrelin receptor was the only differentially expressed gene between LOW and HIGH calves in either the anterior pituitary (P < 0.05) or arcuate nucleus region of the hypothalamus (P < 0.10) and was upregulated in LOW for both tissues. This study indicates that an enhanced plane of nutrition during early calfhood favourably alters the biochemical regulation of the hypothalamus–anterior pituitary–testicular axis, advancing testicular development and hastening spermatogenesis.

Background: The association between the couple relationship and the mothers’ and fathers’ psychological adjustment to the transition to parenthood has been examined in the literature. However, the direction of effects between these variables has not been extensively explored. This study aimed to assess the direction of effects between mothers’ and fathers’ positive and negative interactions and anxiety and depression symptoms trajectories over the transition to parenthood. Methods: A sample of 129 couples (N = 258) completed self-report measures of positive and negative interactions, anxiety and depression symptoms at each trimester of pregnancy, at childbirth, and at 3- and 30-months postpartum. Dyadic growth curve models were performed using multilevel modeling. Results: Whereas anxiety and depression showed no moderation effect on positive and negative interactions over time, negative interaction moderated depression from 3- to 30-months postpartum. Mothers and fathers with high negative interaction scores experienced a steeper increase in depression from 3- to 30-months postpartum. Additionally, gender moderated the effect of positive interaction on anxiety from 3- to 30-months postpartum. Fathers with low positive interaction scores experienced an increase in anxiety, whereas fathers with high positive interaction scores and mothers with high or low positive interaction scores did not experience changes in anxiety from 3- to 30-months postpartum. Limitations: Despite the longitudinal aspect of the models, a possible causal relationship need to be taken with caution. Conclusions: Our results suggest that mothers’ and fathers’ positive and negative interactions affect their anxiety and depression symptoms trajectories: negative interaction raises mothers’ and fathers’ depression symptoms and positive interaction prevents the increase of fathers’ anxiety symptoms over the postpartum period., This study was conducted at Psychology Research Centre (UID/PSI/ 01662/2013), University of Minho, and supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Education and Science through national funds and co‐financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI‐01‐0145‐FEDER‐007653). This study was also supported by FEDER Funds through the Programa Operacional Factores de Competitividade - COMPETE and by National Funds through FCT Fundação para a Ciência e a Tecnologia under the project PTDC/SAU/ SAP/116738/2010 (PI Bárbara Figueiredo). Data analysis were supported by a doctoral grant from FCT Fundação para a Ciência e a Tecnologia (SFRH/BD/50241/2009)., info:eu-repo/semantics/publishedVersion

Aim: To examine whether mode of conception and gender are associated with parents’ psychological adjustment across the transition to twin parenthood. Background: There is limited knowledge on the psychological adjustment of couples to twin parenthood during pregnancy and early postpartum, especially for fathers. The available research suggests that first-time mothers of twins conceived by assisted reproduction techniques (ART) may experience lower psychosocial well-being than mothers of spontaneously conceived (SC) twins. Methods: A total of 41 couples expecting twins, 25 of whom conceived spontaneously and 16 conceived by assisted reproduction techniques, completed measures of depressive and anxiety symptoms, marital relationship, attitudes to sex, and attitudes to pregnancy and the baby. Findings: ART parents showed a decline in marital relationship quality, no changes in attitudes to pregnancy and the baby and no changes in attitudes to sex over the postpartum. In contrast, SC parents did not change their perception of the marital relationship, reported more positive attitudes to pregnancy and the baby, and more positive attitudes to sex over the postpartum. Compared with the other groups (SC mothers and fathers, ART fathers), ART mothers exhibited a higher increase in depressive and anxiety symptoms from pregnancy to postpartum and only anxiety symptoms exhibited a decline trend over the postpartum. These findings suggest that ART parents may experience more psychological difficulties during the transition to twin parenthood than SC parents. ART mothers, in particular, appear to be more at risk of high levels of postpartum depressive symptoms., (undefined), info:eu-repo/semantics/publishedVersion

peer-reviewed The aim of this study was (1) to examine the effect of plane of nutrition during the first and second 6 mo of life on systemic concentrations of reproductive hormones and metabolites in Holstein-Friesian dairy bulls, and (2) to establish relationships with age at puberty and postpubertal semen production potential. Holstein-Friesian bull calves (n = 83) with a mean (standard deviation) age and body weight of 17 (4.4) d and 52 (6.2) kg, respectively, were assigned to a high or low plane of nutrition for the first 6 mo of life. At 24 wk of age, bulls were reassigned, within treatment, either to remain on the same diet or to switch to the opposite diet until puberty, resulting in 4 treatment groups: high-high, high-low, low-low, and low-high. Monthly blood samples were analyzed for metabolites (albumin, urea, total protein, β-hydroxybutyrate, glucose, nonesterified fatty acid, triglycerides and creatinine), insulin, insulin-like growth factor-1, leptin, adiponectin, FSH, and testosterone. A GnRH challenge was carried out at 16 and 32 wk of age (n = 9 bulls per treatment). Blood was collected at 15-min intervals for 165 min, with GnRH administered (0.05 mg/kg of body weight, i.v.) immediately after the third blood sample. Blood samples were subsequently analyzed for LH, FSH, and testosterone. Stepwise regression was used to detect growth and blood measurements to identify putative predictors of age at puberty and subsequent semen quality traits. Metabolic hormones and metabolites, in general, reflected metabolic status of bulls. Although FSH was unaffected by diet, it decreased with age both in monthly samples and following GnRH administration. Testosterone was greater in bulls on the high diet before and after 6 mo of age. Testosterone concentrations increased dramatically after 6 mo of age. Luteinizing hormone was unaffected by diet following GnRH administration but basal serum LH was greater in bulls on a high diet before 6 mo of age. In conclusion, the plane of nutrition offered before 6 mo of age influenced metabolic profiles, which are important for promoting GnRH pulsatility, in young bulls

The objective of this study was to evaluate the endocrine response and metabolic rate in Holstein–Friesian bulls during restricted feeding and realimentation. Sixty bulls were allocated to 1 of 2 feeding regimes: 1) restricted feed allowance (RES; n = 30) or 2) ad libitum feeding (ADLIB; n = 30) for 125 d (Period 1). The bulls in both treatment groups were then offered ad libitum access to feed for a further 55 d (Period 2). Five and 4 blood samples were collected during periods 1 (n = 60) and 2 (n = 30), respectively. Plasma samples were assayed for hormones and metabolites including insulin, IGF-1, leptin, thyroid hormones, albumin, β-hydroxy butyrate (BHB), creatinine, glucose, NEFA, total protein, triglycerides, and urea. Blood pressure measurements were determined on all animals at the beginning and end of each period as an indicator of metabolic rate. During Period 1, RES bulls gained 0.6 kg/d whereas ADLIB bulls grew at 1.9 kg/d. Following realimentation in Period 2, RES bulls displayed accelerated growth, gaining 2.5 kg/d compared with 1.4 kg/d for ADLIB bulls (P < 0.001). Treatment × period interactions (P < 0.05) were evident for all plasma analytes assayed. During Period 1, RES bulls had lower concentrations of glucose and insulin, reflecting their lower feed intake. Adipose and protein tissue mobilization was evident through greater concentrations of triglycerides, NEFA, BHB, creatinine, albumin, and total protein in RES animals in Period 1. Additionally, the effect of restricted feeding on growth was apparent through lower concentrations of IGF-1. A lower metabolic rate was also apparent through lower concentrations of thyroid hormones and fewer beats per minute in RES bulls during Period 1. During the initial stage of realimentation in Period 2, IGF-1, insulin, thyroid hormones, creatinine, glucose, total protein, and triglycerides followed the same pattern as per Period 1 with divergence maintained between RES and ADLIB bulls (P < 0.05), whereas concentrations of all of these hormones and metabolites had converged between the treatment groups by the end of Period 2. During realimentation, the number of heart beats per minute was greater in RES bulls, indicating greater metabolic rate in these animals (P < 0.001). Results from the current study clearly show that feed restriction followed by realimentation affects key indices of metabolic status as well as tissue catabolism and provides an insight into the metabolic control of compensatory growth in cattle.

peer-reviewed Background Caesarean section is a routine veterinary obstetrical procedure employed to alleviate dystocia in cattle. However, CS, particularly before the onset of labour, is known to negatively affect neonatal respiration and metabolic adaptation in humans, though there is little published information for cattle. The aim of this study was to investigate the effect of elective caesarean section (ECS) or normal trans-vaginal (TV) delivery, on lung and jejunal gene expression profiles of neonatal calves. Results Paternal half-sib Angus calves (gestation length 278 + 1.8 d) were delivered either transvaginally (TV; n = 8) or by elective caesarean section (ECS; n = 9) and immediately euthanized. Lung and jejunum epithelial tissue was isolated and snap frozen. Total RNA was extracted using Trizol reagent and reverse transcribed to generate cDNA. For lung tissue, primers were designed to target genes involved in immunity, surfactant production, cellular detoxification, membrane transport and mucin production. Primers for jejunum tissue were chosen to target mucin production, immunoglobulin uptake, cortisol reaction and membrane trafficking. Quantitative real-time PCR reactions were performed and data were statistically analysed using mixed models ANOVA. In lung tissue the expression of five genes were affected (p

Background/Aims: There are numerous treatment options following Traumatic Dental Injury (TDI). Systematic reviews of different treatments are challenging owing to the diversity of outcomes reported between clinical studies. This issue could be addressed through the development and implementation of a agreed and standardised collection of outcomes known as a Core Outcome Set (COS). The aim of this study was to develop a COS for TDI in children and adults. The secondary aim was to establish what, how, when and by whom these outcomes should be measured. Materials and method: The project was registered with Core Outcomes Measures in Effectiveness Trials (COMET). A web-based survey was developed to capture the opinions of dentists globally as to which outcomes should be recorded. A list of outcomes was entered into a Delphi Survey and scored by an Expert Working Group (EWG). The scoring was repeated, followed by conference calls to discuss, refine and finalise the COS. The EWG split into small groups of subject-specific experts to determine how, when and by whom each outcome would be measured. Results: The questionnaire was completed by 1476 dentists. The EWG identified 13 core outcomes to be recorded for all TDI's. An additional 10 injury-specific outcomes were identified. A table has been produced for each outcome detailing what, when, and how each outcome should be recorded. Conclusions: A robust consensus process was used to develop an international COS for TDI in children and adults. This includes both generic and injury-specific outcomes across all identified domains.

peer-reviewed Background Bovine respiratory disease (BRD) is caused by growth of single or multiple species of pathogenic bacteria in lung tissue following stress and/or viral infection. Next generation sequencing of 16S ribosomal RNA gene PCR amplicons (NGS 16S amplicon analysis) is a powerful culture-independent open reference method that has recently been used to increase understanding of BRD-associated bacteria in the upper respiratory tract of BRD cattle. However, it has not yet been used to examine the microbiome of the bovine lower respiratory tract. The objective of this study was to use NGS 16S amplicon analysis to identify bacteria in post-mortem lung and lymph node tissue samples harvested from fatal BRD cases and clinically healthy animals. Cranial lobe and corresponding mediastinal lymph node post-mortem tissue samples were collected from calves diagnosed as BRD cases by veterinary laboratory pathologists and from clinically healthy calves. NGS 16S amplicon libraries, targeting the V3-V4 region of the bacterial 16S rRNA gene were prepared and sequenced on an Illumina MiSeq. Quantitative insights into microbial ecology (QIIME) was used to determine operational taxonomic units (OTUs) which corresponded to the 16S rRNA gene sequences. Results Leptotrichiaceae, Mycoplasma, Pasteurellaceae, and Fusobacterium were the most abundant OTUs identified in the lungs and lymph nodes of the calves which died from BRD. Leptotrichiaceae, Fusobacterium, Mycoplasma, Trueperella and Bacteroides had greater relative abundances in post-mortem lung samples collected from fatal cases of BRD in dairy calves, compared with clinically healthy calves without lung lesions. Leptotrichiaceae, Mycoplasma and Pasteurellaceae showed higher relative abundances in post-mortem lymph node samples collected from fatal cases of BRD in dairy calves, compared with clinically healthy calves without lung lesions. Two Leptotrichiaceae sequence contigs were subsequently assembled from bacterial DNA-enriched shotgun sequences. Conclusions The microbiomes of the cranial lung lobe and mediastinal lymph node from calves which died from BRD and from clinically healthy H-F calves have been characterised. Contigs corresponding to the abundant Leptotrichiaceae OTU were sequenced and found not to be identical to any known bacterial genus. This suggests that we have identified a novel bacterial species associated with BRD. This research, including all experimental procedures, was funded by the Irish Government under the National Development Plan 2007–2013, Department of Agriculture, Food and the Marine (DAFM) Research Stimulus Fund 11/S/131 (B. Earley, Principal Investigator) and EU project: 311,825 (B. Earley, Principal Investigator). The healthy calves were part of a study funded by DAFM Research Stimulus Fund 11/S/322 (D.A. Kenny, Principal Investigator).

peer-reviewed Background When an animal is exposed to a stressor, metabolic rate, energy consumption and utilisation increase primarily through activation of the hypothalamic-pituitary-adrenal (HPA) axis. Changes to partitioning of energy by an animal are likely to influence the efficiency with which it is utilised. Therefore, this study aimed to determine the physiological stress response to an exogenous adrenocorticotropic hormone (ACTH) challenge in beef heifers divergently ranked on phenotypic residual feed intake (RFI). Results Data were collected on 34 Simmental weaning beef heifers the progeny of a well characterized and divergently bred RFI suckler beef herd. Residual feed intake was determined on each animal during the post-weaning stage over a 91-day feed intake measurement period during which they were individually offered adlibitum grass silage and 2 kg of concentrate per head once daily. The 12 highest [0.34 kg DM/d] and 12 lowest [−0.48 kg DM/d] ranking animals on RFI were selected for use in this study. For the physiological stress challenge heifers (mean age 605 ± 13 d; mean BW 518 ± 31.4 kg) were fitted aseptically with indwelling jugular catheters to facilitate intensive blood collection. The response of the adrenal cortex to a standardised dose of ACTH (1.98 IU/kg metabolic BW0.75) was examined. Serial blood samples were analysed for plasma cortisol, ACTH and haematology variables. Heifers differing in RFI did not differ (P = 0.59) in ACTH concentrations. Concentration of ACTH peaked (P

The aim of this study was to examine the effects of dietary supplementation with rumen protected n-6 or n-3 polyunsaturated fatty acids (PUFA) on the quantity and quality of semen from young post-pubertal dairy bulls. Pubertal Holstein-Friesian (n=43) and Jersey (n=7) bulls with a mean±s.e.m. age and bodyweight of 420.1±5.86 days and 382±8.94kg, respectively, were blocked on breed, weight, age and semen quality (based on the outcomes of two pre-trial ejaculates) and randomly assigned to one of three treatments: (i) a non-supplemented control (CTL, n=15), (ii) rumen-protected safflower (SO, n=15), (iii) rumen-protected n-3 PUFA-enriched fish oil (FO, n=20). Bulls were fed their respective diets,ad libitumfor 12 weeks; individual intakes were recorded using an electronic feeding system for the initial 6 weeks of the feeding period. Semen was collected via electro-ejaculation at weeks−2,−1, 0, 7, 10, 11 and 12 relative to the beginning of the trial period (week 0). On collection, semen volume, sperm concentration and progressive linear motility (PLM) were assessed. On weeks−2,−1, 0, 10, 11, 12, semen was packaged into 0.25mL straws and frozen using a programmable freezer. On weeks−1, 7 and 11; a sub-sample of semen was separated into sperm and seminal plasma, by centrifugation and stored at – 20°C until analysis of lipid composition. Semen from 10 bulls per treatment were used for post-thaw analysis at weeks 10, 11 and 12 (3 straws per ejaculate). Sperm motility was analysed by computer assisted semen analysis (CASA). In addition, membrane fluidity, acrosome reaction and oxidative stress were assessed using flow cytometry. Sperm from bulls fed SO had a 1.2 fold higher total n-6 PUFA content at week 11 compared to week−1 (P

Meat quality traits for Holstein–Friesian (HF), Norwegian Red × Holstein–Friesian (NR) and Jersey × Holstein–Friesian (JE) cattle reared to slaughter as two genders (bulls and steers) and 2 slaughter weights (570 kg and 640 kg) were compared. Adipose tissue from JE was more yellow (p

The objectives of this study were to determine the insulinogenic response to an intravenous glucose tolerance test (GTT) and examine gene expression profiles in the insulin signaling pathway (ISP) in beef animals of differing phenotypic residual feed intake (RFI). Two experiments were conducted. In Exp. 1, a total of 39 Simmental heifers, over 2 yr (yr 1, n = 22, and yr 2, n = 17; mean initial BW = 472 kg [SD = 52.4 kg]), were offered grass silage ad libitum for 104 d. Heifers were subjected to a GTT on d 8 and 65 of the RFI measurement period in yr 1 and 2, respectively. Concentrations of plasma glucose and insulin were measured at -45, -30, -15, 0, 5, 10, 15, 20, 30, 45, 60, 90, 120, 150, and 180 min relative to glucose infusion (0 min). In Exp. 2, a total of 67 Simmental bulls, over 3 yr (yr 1, n = 20; yr 2, n = 33; and yr 3, n = 14; mean initial BW = 431 kg [SD = 63.7 kg]), were offered concentrates ad libitum for 105 d. Biopsies of LM were harvested during the RFI measurement period (yr 1, d 49 and 91; yr 2, d 52 and 92; and yr 3, d 50 and 92). The residuals of the regression of DMI on ADG, midtest metabolic BW (BW(0.75)), and the fixed effect of year, using all animals, were used to compute individual RFI coefficients. Animals were ranked on RFI and assigned to high (inefficient), medium, or low groupings by dividing them into terciles, resulting in 13 heifers and 22, 23, and 22 bulls in their respective RFI groups. In Exp. 1, data from 13 heifers from each of the high- and low-RFI groups, and in Exp. 2, data from the 15 highest and 15 lowest ranking bulls on RFI are reported. In Exp. 1, glucose and insulin response and area under the response curve for glucose and insulin were similar (P > 0.05) between high- and low-RFI heifers. In Exp. 2, no differences (P > 0.05) were found for mRNA expression of 22 genes of the ISP in muscle tissue; however, expression of the transcription factor SREBP1c tended to be positively correlated (r = 0.25, P = 0.07) with RFI. Expression of GLUT4, INPPL1, and SHC increased (P < 0.05) over time, while there was no effect of sample time for any other genes measured. Collectively, these results suggest that insulin response, sensitivity, and associated expression of genes in the ISP within muscle tissue are not contributory factors to variation in RFI. However, further examination of target genes of SREBP1c, which is involved in lipogenesis, may explain some of the biochemical processes underlying variation in phenotypic RFI.

Dietary n-3 polyunsaturated fatty acid (n-3 PUFA) supplementation is postulated to have positive effects on fertility. The impact of dietary n-3 PUFA supplementation on physiological and biochemical processes involved in reproduction is likely to be associated with significant alterations in gene expression in key reproductive tissues which is in turn regulated by transcription factors. Beef heifers were supplemented with a rumen protected source of either a saturated fatty acid or high n-3 PUFA diet per animal per day for 45 days and uterine endometrial tissue was harvested post slaughter. A microarray analysis was conducted and bioinformatic tools were employed to evaluate the effect of n-3 PUFA supplementation on gene expression in the bovine endometrium. Clustering of microarray gene expression data was performed to identify co-expressed genes. Functional annotation of each cluster of genes was carried out using Ingenuity Pathway Analysis. Furthermore, oPOSSUM was employed to identify transcription factors involved in gene expression changes due to supplementary PUFA. Gene functions which showed a significant response to n-3 PUFA supplementation included tissue development, immune function and reproductive function. Numerous transcription factors such as FOXD1, FOXD3, NFKB1, ESR1, PGR, FOXA2, NKX3-1 and PPARα were identified as potential regulators of gene expression in the endometrium of cattle supplemented with n-3 PUFA. This study demonstrates the complex nature of the alterations in the transcriptional regulation process in the uterine endometrium of cattle following dietary supplementation which may positively influence the uterine environment.

Project EXPLORE - a large-scale, behavioral intervention tested among men who have sex with men (MSM) at-risk for HIV infection - was generally deemed as ineffective in reducing HIV incidence. Using novel and more precise data analytic techniques we reanalyzed Project EXPLORE by including both direct and indirect paths of intervention effects. Data from 4296 HIV-negative MSM who participated in Project EXPLORE, which included 10 sessions of behavioral risk reduction counseling completed from 1999 to 2005, were included in the analysis. We reanalyzed the data to include parameters that estimate the over-time effects of the intervention on unprotected anal (UA) sex and the over-time effects of the intervention on HIV status mediated by UA sex simultaneously in a single model. We found the indirect effect of intervention on HIV infection through UA sex to be statistically significant up through 12-month post-intervention, OR = 0.83, 95% CI = 0.72-0.95. Furthermore, the intervention significantly reduced UA sex up through 18-month post-intervention, OR = 0.79, 95% CI = 0.63-0.99. Our results reveal effects not tested in the original model that offer new insight into the effectiveness of a behavioral intervention for reducing HIV incidence. Project EXPLORE demonstrated that when tested against an evidence-based, effective control condition can result in reductions in rates of HIV acquisition at one year follow-up. Findings highlight the critical role of addressing behavioral risk reduction counseling in HIV prevention.

The objectives of the study were to quantify the phenotypic variation in residual feed intake (RFI) and productivity of beef suckler cows offered grass silage during pregnancy and, to determine the effect of RFI classification on herbage intake during lactation. Data were collected on 39 Simmental and Simmental×Holstein-Friesian cows. During the winter indoor feeding period cows were offered grass silage ad libitum daily and their individual DMI was recorded over 73 d. Cow LW, BCS, skeletal measurements, ultrasonic fat and muscle depth, visual muscularity score, rumen fermentation, total tract digestibility, blood metabolites and haematological variables, as well as feeding behaviour were measured. Phenotypic RFI was calculated for each animal as the difference between actual silage DMI and expected silage DMI. Expected silage DMI was computed for each animal by regressing average daily silage DMI on conceptus adjusted mean LW0.75 and conceptus adjusted ADG over a 73-d period. Within breed, cows were ranked by RFI into low (efficient), medium and high (inefficient) groups by dividing them into thirds. Overall mean (SD) values for grass silage DMI (kg/d), grazed grass DMI (kg/d), feed conversion ratio (FCR) kg DMI/kg of LW gain (kg/d) and RFI (kg DM/d) were 9.08 (1.15), 9.98 (1.86), 24.66 (29.61), 0.00 (1.00), respectively. The RFI groups did not differ (P>0.05) in LW or ADG at any stage of measurement. Residual feed intake was positively correlated with silage DMI (r=0.87; P 0.05). Cows in the low RFI group consumed 14% (P 0.05). Cow RFI groups did not differ (P>0.05) in BCS, ultrasonic backfat or rump fat thickness, visual muscle scores or total tract digestibility, cow milk yield, calving difficulty score, calf birth weight and ADG of calves did not differ (P>0.05) between RFI groups. Overall, this study showed that low RFI cows were more biologically and economically efficient, as they consumed less feed during the indoor winter period and a similar amount of herbage during the grazing season compared to high RFI cows, without any compromise in growth, body composition or production traits measured.