Impact of proximal cytoplasmic droplets on quality traits and in-vitro embryo production efficiency of cryopreserved bull spermatozoa

Background

Proximal cytoplasmic droplets (PCDs), a remnant of germ cell cytoplasm, are common non-specific morphological defects in bovine semen. This study evaluated the effect of higher percentages of PCDs on the quality of frozen-thawed bovine semen, embryo production and early embryo development.

Methods

Three ejaculates from each of five (group 1: PCD ≤ 1%, control) and eight adult Bos indicus bulls (group 2: PCD ≥ 24%) were analysed. Semen samples were examined for: post-thaw motility, vigour of movement, concentration, sperm morphology, slow thermoresistance test (STT), membrane integrity, acrosome status, mitochondrial function using fluorescent probes association (FITC-PSA, PI and JC-1) and sperm chromatin integrity using acridine orange assay. Two bulls from group 2, with 28.5% and 48.5% PCD, respectively, and three bulls from the control group, each with 0% PCD, were selected for IVF (in vitro fertilisation).

Results

Semen analyses revealed a significant correlation (P < 0.01) between increased rates of PCD and sperm quality traits. Nevertheless, no differences were observed in sperm motility and vigour either before or after the STT or in the percentage of intact acrosomes (analysed by differential interference contrast microscopy (DIC) after STT), but membrane integrity, acrosome status (evaluated with FITC-PSA staining method after thawing) and mitochondrial function were reduced, when compared with group 1 (P < 0.05). The higher incidence of PCD was positively correlated to chromatin damage, especially after three hours of incubation at 37°C. IVF showed similar results for bull C2 (group 1, control) and bull P2 (group 2, group with higher PCDs).

Conclusion

Higher PCD levels influenced spermatozoa quality traits. IVF and embryo development data showed that cleavage, blastocyst formation and blastocyst hatching may have been influenced by the interaction of morphology traits and individual bull effects.     

A 16 kb naturally occurring genomic deletion including mce and PPE genes in Mycobacterium avium subspecies paratuberculosis isolates from goats with Johne's disease

In October and November 2010, novel H1N2 reassortant influenza viruses were identified from pigs showing mild respiratory signs that included cough and depression. Sequence and phylogenetic analysis showed that the novel H1N2 reassortants possesses HA and NA genes derived from recent H1N2 swine isolates similar to those isolated from Midwest. Compared to the majority of reported reassortants, both viruses preserved human-like host restrictive and putative antigenic sites in their HA and NA genes. The four internal genes, PB2, PB1, PA, and NS were similar to the contemporary swine triple reassortant viruses' internal genes (TRIG). Interestingly, NP and M genes of the novel reassortants were derived from the 2009 pandemic H1N1. The NP and M proteins of the two isolates demonstrated one (E16G) and four (G34A, D53E, I109T, and V313I) amino acid changes in the M2 and NP proteins, respectively. Similar amino acid changes were also noticed upon incorporation of the 2009 pandemic H1N1 NP in other reassortant viruses reported in the U.S. Thus the role of those amino acids in relation to host adaptation need to be further investigated. The reassortments of pandemic H1N1 with swine influenza viruses and the potential of interspecies transmission of these reassortants from swine to other species including human indicate the importance of systematic surveillance of swine population to determine the origin, the prevalence of similar reassortants in the U.S. and their impact on both swine production and public health.     

Influence of equine chorionic gonadotropin on weaning-to-estrus interval and estrus duration in early-weaned, primiparous, female swine

The weaning-to-estrus interval (WEI) influences the total nonproductive days (NPD) accumulated by the breeding herd and affects herd productivity. Short lactation lengths (LL) are commonly followed by prolonged WEI, which are also associated with short estrus duration (ED). Equine chorionic gonadotropin treatment is a tool that has been used to reduce WEI, especially for low-parity females. The objectives for this study were to evaluate the effect of LL on the association between WEI and ED and to estimate the effects of postweaning eCG administration on WEI and ED for early-weaned females. Two treatments (TREAT) consisting of 750 IU of eCG (n = 96) or control (n = 77) were applied 1 d after weaning to first-parity, weaned females. The study was conducted on a commercial farm having a target LL of 18 d. Estrus detection was conducted three times daily, and estrus duration was determined as the interval between the first and the last positive response to back pressure. Analyses of variance were conducted to estimate the effects of LL and TREAT on WEI and the effects of TREAT and WEI on estrus duration. Mean LL was 17.9+/-1.7 d, mean WEI was 106.6+/-29.2 h, and mean estrus duration was 55.9+/-15.5 h. Even though the frequency of short WEI tended to increase with longer LL, mean WEI was shortest for females weaned after 18 d and longest for those weaned after 20 d (P<.05). The WEI for females receiving eCG (98.7+/-2.7 h) was shorter (P = .0001) than that for control females (121.5+/-3.3 h). The WEI was also affected by a LL x TREAT interaction (P = .0014), indicating that the interval was longer (P<.05) for control females weaned after 17 and 20+ d than for other females. The LL and TREAT did not affect estrus duration (P = .20 and P = .157, respectively). However, estrus duration was reduced as the WEI increased (P = .0001), and it was also influenced by a WEI x TREAT interaction (P = .024). A linear regression model estimated that the association between WEI and estrus duration was stronger in the eCG group than in the control group (R2 = .51 and .15, respectively; both P<.001). In conclusion, the use of eCG postweaning was associated with more precise prediction of estrus duration as a function of the WEI and allows optimization of breeding management in early-weaned, primiparous females.     

Embryonic development and influence of egg density on early veliger larvae and effects of dietary microalgae on growth of brown mussel Perna perna (L. 1758) larvae under laboratory conditions

The effect of egg density on embryonic development and larval quality as well as the lipid and fatty acid contents (eicosapentaenoic acid, EPA; docosahexaenoic acid, DHA) of cultured microalgae fed to Perna perna larvae was studied under controlled conditions to provide information needed for development of an experimental hatchery. Embryonic development followed the common sequence exhibited by other bivalves. d-larva stage was attained 40–44 h post-fertilisation at 21 ± 1 °C. The umbo-stage was reached in 11 days, and pediveliger larvae were observed 26 days post-fertilisation. Low egg density (range 20–100 eggs cm^?2) produced high proportions of normal d-larvae. Larval development showed two growth phases: 1st—the mixotrophic stage and 2nd—the exotrophic stage where the composition of diets had significant effects on larval growth with higher rates in larvae fed with the mixed microalgae (Isochrysis galbana + Chaetoceros calcitrans, I. galbana + Phaeodactylum tricornutum and I. galbana + Skeletonema costatum) in comparison with the monospecific diet (I. galbana). Fatty acid analysis showed that larval growth and survival were strongly influenced by proportions of dietary DHA and EPA. These results indicate that DHA and EPA are the key factors in determining larval performance, considerably more than the total amount of other fatty acids.     

Generation of reactive oxygen species by leukocytes of Prochilodus lineatus

Prochilodus lineatus (curimbatá), from the Procholodontidae family, is a Brazilian freshwater fish, which is important commercially, nutritionally and ecologically. It is encountered in the Rio da Prata Bay in Southern South America. Studies on the immune system of this fish are scarce, but the physiological mechanisms of the species are analogous to those of other vertebrates. Thus, this work discusses the present study, which correlates P. lineatus leukocytes and the generation of reactive oxygen species after modulatory stimuli. Leukocytes were characterized by light and electron transmission microscopy and investigated by the generation of H₂O₂ and O₂ ^?, using phenol red, flow-cytometry and electron transmission histochemistry. The study determined that monocytes and neutrophils are the main cells responsible for generating O₂ after stimulation with phorbol myristate acetate. Superoxide dismutase successfully inhibited the generation of reactive oxygen species in neutrophils and monocytes, but stimulated generation when in association with phorbol myristate acetate. Fish leukocyte samples from P. lineatus showed cross-reactivity with antibodies directed against human NADPH-oxidase antibody subunits (p47^phox and p67^phox). Thus, catalase enhanced the presence of p47^phox. Neutrophil mitochondria were shown to be generators of H₂O₂ (charged by cerium precipitate), being enlarged and changing their format. The present study contributes to a better understanding of the respiratory burst pathways in this species and suggests mitochondria as the organelle responsible for generation of reactive oxygen species.     

Cutaneous and gastrointestinal pythiosis in a dog in Brazil

The oomycete Pythium insidiosum is the pathogenic cause of pythiosis, a life-threatening disease that affects several animal species. Canines are the second most affected species, and the disease is characterized by the development of cutaneous and gastrointestinal lesions. While concomitant cutaneous and gastrointestinal lesions are rarely found in the same animal, this report documents a case of concurrent cutaneous and gastrointestinal pythiosis in an 18-month-old female Labrador. This dog had an ulcerative cutaneous lesion on the right thoracic region for 12 months that was unresponsive to itraconazole and terbinafine therapy. Two months prior to death and concurrent with the cutaneous lesion, the dog became anorexic with frequent vomiting and bloody stools. At necropsy, a cutaneous lesion that extended subcutaneously into the intercostal muscles was observed. Additionally, the large intestine contained two lesions that caused luminal narrowing. Organs were collected, routinely processed and stained using hematoxylin and eosin and Gomori methenamine silver. Histological examination of the lesions in the large intestine and on the skin revealed areas of necrosis surrounded by a pyogranulomatous infiltrate. Occasionally, black, septate, branching hyphae were detected following staining with Gomori methenamine silver. The diagnosis of pythiosis was confirmed using immunohistochemical methods. This report describes the occurrence of concomitant gastrointestinal and cutaneous lesions in a dog and highlights the therapeutic difficulties encountered with this disease.     

The role of absorbed hemicelluloses on final paper properties and printability

Hemicelluloses isolated from eucalyptus wood were adsorbed onto both bleached eucalyptus kraft pulp and pine kraft pulp as part of a general strategy to investigate their role on final sheet mechanics and physical properties. The tensile indices increased upon hemicelluloses addition and respectively reached a maximum at 9 mg/g and 10 mg/g hemicelluloses adsorption for bleached eucalyptus kraft pulp and pine kraft pulp, whereas the tear index increased depending on the pulp type. The air permeability and surface roughness of the bleached eucalyptus kraft pulp slightly decreased, however, brightness and opacity did not changed. SEM analysis shows that hemicelluloses adsorption increases bleached eucalyptus kraft pulp fibers interaction, whereas the effect of hemicelluloses addition on the beaten pine kraft pulp is unclear. The hemicelluloses adsorption also affected printability. It was found that print through for the bleached eucalyptus kraft pulp hand sheet slightly decreased, but for the bleached pine kraft pulp hand sheet it was unaffected. Print densities were not influenced.