Prevalence of Tritrichomonas foetus in beef bulls slaughtered at two abattoirs in northern Australia

Bovine trichomoniasis, caused by the protozoal parasite Tritrichomonas foetus, is a highly contagious venereal disease characterised by early pregnancy loss, abortion and pyometra. Persistently infected bulls and cows are the primary reservoirs of infection in infected herds. This research investigated the prevalence of T. foetus infection in bulls from properties located across northern Australia and New South Wales. Preputial samples were collected from 606 bulls at slaughter and tested for T. foetus using the VetMAX-Gold Trich Detection Kit (Thermo Fisher Scientific). The apparent prevalence of T. foetus infection varied between regions, with northern regions in the Northern Territory, Queensland and Western Australia showing a prevalence of 15.4%, 13.8% and 11.4%, respectively. There was some evidence of an association between infection and postcode (P = 0.06) and increasing bull age (P = 0.054). This study confirms that T. foetus infection is likely to be present in many beef breeding herds and contributing to lower than expected reproductive performance, particularly across northern Australia

Evaluation and histological examination of a Campylobacter fetus subsp. venerealis small animal infection model

Bovine genital campylobacteriosis (BGC), caused by Campylobacter fetus subsp. venerealis, is associated with production losses in cattle worldwide. This study aimed to develop a reliable BGC guinea pig model to facilitate future studies of pathogenicity, abortion mechanisms and vaccine efficacy. Seven groups of five pregnant guinea pigs (1 control per group) were inoculated with one of three strains via intraperitoneal (IP) or intra-vaginal routes. Samples were examined using culture, PCR and histology. Abortions ranged from 0% to 100% and re-isolation of causative bacteria from sampled sites varied with strain, dose of bacteria and time to abortion. Histology indicated metritis and placentitis, suggesting that the bacteria induce inflammation, placental detachment and subsequent abortion. Variation of virulence between strains was observed and determined by culture and abortion rates. IP administration of C fetus subsp. venerealis to pregnant guinea pigs is a promising small animal model for the investigation of BGC abortion. (C) 2014 Elsevier Ltd. All rights reserved

A field investigation of a modified intravaginal progesterone releasing device and oestradiol benzoate based ovulation synchronisation protocol designed for fixed-time artificial insemination of Brahman heifers

Pregnancy rates (PR) to fixed-time AI (FTAI) in Brahman heifers were compared after treatment with a traditional oestradiol-based protocol (OPO-8) or a modified protocol (OPO-6) where the duration of intravaginal progesterone releasing device (IPRD) was reduced from 8 to 6 days, and the interval from IPRD removal to oestradiol benzoate (ODB) was increased from 24 to 36h. Rising 2 yo heifers on Farm A: (n=238 and n=215; two consecutive days AI); B (n=271); and C (n=393) were allocated to OPO-8 or OPO-6. An IPRD was inserted and 1 mg ODB i.m. on Day 0 for OPO-8 heifers and Day 2 for OPO-6 heifers. On Day 8, the IPRD was removed and 500 mu g cloprostenol i.m. At 24h, for OPO-8 heifers, and 36 h, for OPO-6 heifers, post IPRD removal all heifers received 1 mg ODB i.m. FTAI was conducted at 54 and 72 h post IPRD removal for OPO-8 and OPO-6 heifers. At Farm A, OPO-6 heifers, AI on the second day, the PR was 52.4% to FTAI (P = 0.024) compared to 36.8% for OPO-8 heifers. However, no differences were found between OPO-8 and OPO-6 protocols at Farm A (first day of AI) (39.9 vs. 35.7%), or Farms B (26.2 vs. 35.4%) and C (43.2% vs. 40.3%). Presence of a corpus luteum at IPRD insertion affected PR to FTAI (43.9% vs. 28.8%; P < 0.001). This study has shown that the modified ovulation synchronisation protocol OPO-6 may be a viable alternative to the OPO-8 protocol for FTAI in B. indicus heifers. (C) 2015 Elsevier B.V. All rights reserved

Transcriptome analyses identify five transcription factors differentially expressed in the hypothalamus of post-versus prepubertal Brahman heifers

Puberty onset is a developmental process influenced by genetic determinants, environment, and nutrition. Mutations and regulatory gene networks constitute the molecular basis for the genetic determinants of puberty onset. The emerging knowledge of these genetic determinants presents opportunities for innovation in the breeding of early pubertal cattle. This paper presents new data on hypothalamic gene expression related to puberty in Bos indicus (Brahman) in age-and weight-matched heifers. Six postpubertal heifers were compared with 6 prepubertal heifers using whole-genome RNA sequencing methodology for quantification of global gene expression in the hypothalamus. Five transcription factors (TF) with potential regulatory roles in the hypothalamus were identified in this experiment: E2F8, NFAT5, SIX5, ZBTB38, and ZNF605. These TF genes were significantly differentially expressed in the hypothalamus of postpubertal versus prepubertal heifers and were also identified as significant according to the applied regulatory impact factor metric (P < 0.05). Two of these 5 TF, ZBTB38 and ZNF605, were zinc fingers, belonging to a gene family previously reported to have a central regulatory role in mammalian puberty. The SIX5 gene belongs to the family of homologues of Drosophila sine oculis (SIX) genes implicated in transcriptional regulation of gonadotrope gene expression. Tumor-related genes such as E2F8 and NFAT5 are known to affect basic cellular processes that are relevant in both cancer and developmental processes. Mutations in NFAT5 were associated with puberty in humans. Mutations in these TF, together with other genetic determinants previously discovered, could be used in genomic selection to predict the genetic merit of cattle (i.e., the likelihood of the offspring presenting earlier than average puberty for Brahman). Knowledge of key mutations involved in genetic traits is an advantage for genomic prediction because it can increase its accuracy

Relationship between sperm quality traits and field-fertility of porcine semen

An investigation involving seven boars, active in artificial insemination, and 1,350 multiparous sows was conducted at a private farm and aimed at examining the relationship between sperm quality traits and boar fertility in terms of farrowing rate and litter size. This experiment was done for 6 months. The semen samples were evaluated for subjective sperm motility and concentration. Ejaculates with at least 1 × 108 sperm/mL and 70% sperm progressive motility were extended with a commercial medium to 30 × 106 sperm/mL and used for artificial insemination (AI). AI dose was 100 mL semen containing 3 × 109 spermatozoa. Aliquots of diluted semen were assessed for live morphologically normal spermatozoa (LMNS, eosin-nigrosin stain exclusion assay) and sperm chromatin instability (SCI, acridine orange assay). Farrowing rates according to different boar sperm varied (p < 0.001) from 59.3 to 88.92%. The mean values of LMNS (47.2~76.5%) and SCI (0.16~4.67%) differed significantly among boars. LMNS (r = 0.79, p < 0.05) and SCI (r = -0.90, p < 0.02) accounted for 62.2 and 81.7% of the variability in farrowing rates, respectively. After the combination of sperm traits, the relationship between percentage of LMNS with stable chromatin structure and farrowing rate was significant (r = 0.86, p < 0.05). The number of live piglets per parturition was not significantly correlated with sperm quality attributes. In conclusion, boar fertility after AI with freshly diluted semen can be predicted based on the evaluation of sperm morphology and chromatin integrity

Mouse Transcobalamin Has Features Resembling both Human Transcobalamin and Haptocorrin

In humans, the cobalamin (Cbl) -binding protein transcobalamin (TC) transports Cbl from the intestine and into all the cells of the body, whereas the glycoprotein haptocorrin (HC), which is present in both blood and exocrine secretions, is able to bind also corrinoids other than Cbl. The aim of this study is to explore the expression of the Cbl-binding protein HC as well as TC in mice. BLAST analysis showed no homologous gene coding for HC in mice. Submaxillary glands and serum displayed one protein capable of binding Cbl. This Cbl-binding protein was purified from 300 submaxillary glands by affinity chromatography. Subsequent sequencing identified the protein as TC. Further characterization in terms of glycosylation status and binding specificity to the Cbl-analogue cobinamide revealed that mouse TC does not bind Concanavalin A sepharose (like human TC), but is capable of binding cobinamide (like human HC). Antibodies raised against mouse TC identified the protein in secretory cells of the submaxillary gland and in the ducts of the mammary gland, i.e. at locations where HC is also found in humans. Analysis of the TC-mRNA level showed a high TC transcript level in these glands and also in the kidney. By precipitation to insolubilised antibodies against mouse TC, we also showed that >97% of the Cbl-binding capacity and >98% of the Cbl were precipitated in serum. This indicates that TC is the only Cbl-binding protein in the mouse circulation. Our data show that TC but not HC is present in the mouse. Mouse TC is observed in tissues where humans express TC and/or HC. Mouse TC has features in common with both human TC and HC. Our results suggest that the Cbl-binding proteins present in the circulation and exocrine glands may vary amongst species

Paternal effects on early embryogenesis

Historically, less attention has been paid to paternal effects on early embryogenesis than maternal effects. However, it is now apparent that certain male factor infertility phenotypes are associated with increased DNA fragmentation and/or chromosome aneuploidies that may compromise early embryonic development. In addition, there is a growing body of evidence that the fertilizing sperm has more function than just carrying an intact, haploid genome. The paternally inherited centrosome is essential for normal fertilization, and the success of higher order chromatin packaging may impact embryogenesis. Epigenetic modifications of sperm chromatin may contribute to the reprogramming of the genome, and sperm delivered mRNA has also been hythesized to be necessary for embryogenesis. There is less information about the epigenetic factors affecting embryogenesis than genetic factors, but the epigenetics of gamete and early embryogenesis is a rapidly advancing field

Spermatozoal sensitive biomarkers to defective protaminosis and fragmented DNA

Human sperm DNA damage may have adverse effects on reproductive outcome. Infertile men possess substantially more spermatozoa with damaged DNA compared to fertile donors. Although the extent of this abnormality is closely related to sperm function, the underlying etiology of ensuing male infertility is still largely controversial. Both intra-testicular and post-testicular events have been postulated and different mechanisms have been proposed to explain the presence of damaged DNA in human spermatozoa. Three among them, i.e. abnormal chromatin packaging, oxidative stress and apoptosis, are the most studied and discussed in the present review. Furthermore, results from numerous investigations are presented, including our own findings on these pathological conditions, as well as the techniques applied for their evaluation. The crucial points of each methodology on the successful detection of DNA damage and their validity on the appraisal of infertile patients are also discussed. Along with the conventional parameters examined in the standard semen analysis, evaluation of damaged sperm DNA seems to complement the investigation of factors affecting male fertility and may prove an efficient diagnostic tool in the prediction of pregnancy outcome