Characteristic features of porcine endogenous retroviruses in Vietnamese native pigs

We aimed to clarify the genomic characteristics of porcine endogenous retroviruses (PERVs) in Vietnamese native pig (VnP) breeds. First, we investigated genetic polymorphisms in β‐ and γ‐like PERVs, and we then measured the copy numbers of infectious γ‐like PERVs (PERV‐A, B, and C). We purified genomic DNA from 15 VnP breeds from 12 regions all over the country and three Western pig breeds as controls, and investigated genetic polymorphisms in all known PERVs, including the beta (β)1–4 and gamma (γ)1–5 groups. PERVs of β1, β2, β3, and γ4 were highly polymorphic with VnP‐specific haplotypes. We did not identify genetic polymorphisms in β4, γ1, or γ2 PERVs. We then applied a real‐time polymerase chain reaction–based method to estimate copy numbers of the gag, pol, and env genes of γ1 PERVs (defined as A, B, and C). VnP breeds showed significantly lower copy number of the PERV genes compared with the Western pig breeds (on average, 16.2 and 35.7 copies, respectively, p < .05). Two VnP breeds showed significantly higher copy number compared with the other VnPs (p < .05). Our results elucidated that VnPs have specific haplotypes and a low copy number of PERV genes.     

Selection based on morphological features of porcine embryos produced by in vitro fertilization: Timing of early cleavages and the effect of polyspermy

The aim of this study was to examine whether a morphological approach is efficient for selecting high‐quality porcine embryos produced by in vitro fertilization (IVF) under high polyspermy conditions. Frozen‐thawed Meishan epididymal spermatozoa showing moderate and high polyspermy were subjected to IVF (1 × 10⁵ sperms/ml). Under conditions of moderate polyspermy, 4‐cell embryos selected at 48 hr after IVF (single selection) and 8‐cell embryos selected at 79 hr after IVF from the collected 4‐cell embryos (double selection) showed high developmental competence. Likewise, 4‐ and 8‐cell embryos produced by IVF under high polyspermy conditions also showed high competence for development to blastocysts. However, blastocysts derived from high polyspermy conditions had significantly fewer cells than those produced under moderate polyspermy conditions. Furthermore, the frequency of nuclear and chromosomal abnormalities in 4‐ and 8‐cell embryos produced under conditions of high polyspermy was significantly (p < .05) higher in comparison to moderate polyspermy conditions. These findings suggest that although high polyspermy affects the frequency of nuclear and chromosomal anomalies in porcine IVF embryos, subsequent selection based on morphological features of 4‐ and 8‐cell embryos even under high polyspermy conditions, could be an alternative option for selecting porcine IVF embryos with high development ability.     

Surveillance of swine influenza viruses in sentinel familial farms in Hung Yen province in Northern Vietnam in 2013–2014

From May 2013 to April 2014, 15 swine family‐run farms (17 pig litters) in two districts in Hung Yen province, near Hanoi, were virologically and epizootiologically monitored for swine influenza viruses (SIV) monthly. No SIV was isolated from nasal swabs. Maternal antibodies were detected in 10 litters, and seroconversion against SIV was detected in six litters. There was a marked difference in patterns of SIV transmission in the two districts. Van Lam district which has low density of swine with mainly smallholder farms had low intensity of SIV, with much of the infection caused by H1N1 2009 pandemic‐like viruses A(H1N1)pdm09, likely originated from humans. In contrast, Van Giang district, which has high swine density and larger farms, had high levels of typical SIV (triple reassortants H3N2 and H3N2 Binh Duong lineage viruses) circulating within swine. With one exception, the SIV lineages detected were those we concurrently isolated from studies in a large central abattoir in Hanoi. Influenza‐like illness symptoms reported by farmers were poorly correlated with serological evidence of SIV infection.     

Chemical inactivation of protein toxins on food contact surfaces

We compared the kinetics and efficacies of sodium hypochlorite, peracetic acid, phosphoric acid-based detergent, chlorinated alkaline detergent, quaternary ammonium-based sanitizer, and peracetic acid-based sanitizer for inactivating the potential bioterrorism agents ricin and abrin in simple buffers, food slurries (infant formula, peanut butter, and pancake mix), and in dried food residues on stainless steel. The intrinsic fluorescence and cytotoxicity of purified ricin and abrin in buffers decreased rapidly in a pH- and temperature-dependent manner when treated with sodium hypochlorite but more slowly when treated with peracetic acid. Cytotoxicity assays showed rapid and complete inactivation of ricin and crude abrin in food slurries and dried food residues treated 0-5 min with sodium hypochlorite. Toxin epitopes recognized by ELISA decayed more gradually under these conditions. Higher concentrations of peracetic acid were required to achieve comparable results. Chlorinated alkaline detergent was the most effective industrial agent tested for inactivating ricin in dried food residues.     

Historical Profiles of Trace Element Concentrations in Mangrove Sediments from the Ba Lat Estuary,Red River,Vietnam

Historical profiles of trace element concentrations were reconstructed from two mangrove sediment cores collected within the Ba Lat Estuary (BLE), Red River, Vietnam. Chronologies of sediment cores were determined by the ²¹⁰Pb method, which showed that each respective sediment core from the south and north entrances of BLE provided a record of sediment accumulation spanning approximately 100 and 60 years. The profiles of Pb, Zn, Cu, Cr, V, Co, Sb, and Sn concentrations markedly increased from the years of the 1920s–1950s, and leveled out from 1950s–1980s, and then gradually decreased from 1980s to present. The profiles of Cd and Ag concentrations increased from 1920s–1940s, and then decreased from 1940s to present. The profile of Mo concentrations progressively increased from 1920s–1980s, then decreased to present. The Mn concentrations failed to show a clear trend in both sediment cores. Results from contamination factors, Pearson’s correlation, and hierarchical cluster analysis suggest that the trace elements were likely attributed to discharge of untreated effluents from industry, domestic sewage, as well as non-point sources. Pollution Load Index (PLI) revealed levels higher than other mangrove sediment studies, and the long-term variations in PLI matched significant socioeconomic shifts and population growth in Vietnam. Geoaccumulation Index showed that mangrove sediments were moderately polluted by Pb and Ag, and from unpolluted to moderately polluted by Zn, Cu, and Sb. The concentrations of Pb, Zn, Cu, Cr, and Cd exceeded the threshold effect levels and effect range low concentrations of sediment quality guidelines, implying that the sediments may be occasionally associated with adverse biological effects to benthic organisms.     

The impacts of China-ASEAN Free Trade Area

There is little doubt that China-ASEAN Free Trade Area (CAFTA) is important to ASEAN.As a rapidly growing economy,China offers enormous potential for the largely small and export-oriented ASEAN member countries.China’s importance is even more evident at present with a fragile and uncertain global economic recovery and grave economic difficulties faced by the industrial world on which ASEAN countries rely heavily.Through closer integration within the region and with China,CAFTA helps small ASEAN countries pool resources and combine markets.Needless to say,China’s increasing integration with the world trading system also presents tremendous competitive pressure on its smaller neighbors.For ASEAN,instituting a more inclusive CAFTA,which covers trade in goods and services as well as investment activities,is essential for forging a comprehensive economic partnership with China and enabling a deeper economic integration in the long run.     

Practice on improving fattening local cattle production in Vietnam by increasing crude protein level in concentrate and concentrate level

Two experiments were conducted to determine the effects of crude protein (CP) level in concentrate (experiment 1) and concentrate level (experiment 2) on feed intake, nutrient digestibility, nitrogen (N) retention, ruminal pH and NH₃-N concentration and average daily gain (ADG) of Vietnamese local fattening cattle. Animals (24 cattle, initial live weight (LW) 150.3?±?11.8 kg in experiment 1 and 145.1?±?9.8 kg in experiment 2) were allotted based on LW to one of four treatments in a randomised complete block design. In experiment 1, concentrate with four levels of CP (10, 13, 16 and 19 %) was fed at 1.5 % of LW. In experiment 2, concentrate was fed at 1.0, 1.4, 1.8 and 2.2 % of LW. In both experiments, roughage was 5 kg/day native grass and ad libitum rice straw (fresh basis). Results showed that the CP level in concentrate significantly affected dry matter (DM) intake (P?<?0.05), N retention, ADG and ruminal NH₃-N concentration (P?<?0.01), but it had no significant effect on DM, organic matter (OM) and neutral detergent fibre (NDF) digestibility (P?>?0.05), whereas CP digestibility increased (P?<?0.001) along with the CP level. DM intake, N retention and ADG increased (P?<?0.001) linearly with concentrate intake. DM and CP digestibility were not significantly affected by concentrate intake (P?>?0.05). OM digestibility and NH₃-N concentration increased linearly (P?<?0.05), whereas NDF digestibility and ruminal pH declined linearly with increased concentrate consumption (P?<?0.01). These results indicate that 16 % CP in concentrate and feeding concentrate at the rate of 2.2 % of LW are recommendable for fattening local cattle in Vietnam.     

Oats (Avena strigosa) as winter forage for dairy cows in Vietnam: an on-farm study

In North Vietnam, during winter, alternative forage resources are needed to balance the feed ration of dairy cows. The objective of this study was to investigate the effect of oat forage as a component of traditional winter roughage diets on feed intake, milk production and feeding cost in dairy cows. The study was conducted on-farm using 24 mid-lactation Holstein–Friesian cows. The feeding experiment consisted of two successive periods and two dietary treatments per period. Traditional basal diets included fresh tropical grasses, maize silage and hay. The oat forage had no effect on the dry matter intake of the basal diet, but the total crude protein intake was higher in cows fed with oat diets than in those fed with control diets. The yield of butterfat-corrected milk (FCM) was not significantly different between diets during period 1, but there was a trend (P?=?0.078) of higher FCM yields in cows fed with the oat diet compared to those with control diet during period 2 (17.3 vs. 16.3 kg/day). The decline rate in milk yield was significantly higher (P?<?0.001) in cows fed with control diets than in those fed with oat diets in both experimental periods. The total feeding cost of cows fed with oat diets was on average 12 % lower than those fed with control diets (P?<?0.01). So, the oat forage is an important winter resource for cows in North Vietnam allowing higher milk yield whilst reducing feeding cost, compared to traditional roughage diets.     

Cryopreservation of immature oocytes of the indigeneous Vietnamese Ban Pig

We report the cryopreservation of oocytes from Ban miniature pigs which are endemic in Vietnam. Immature cumulus‐oocyte complexes were collected from antral follicles of 7–8 mo old female cyclic Ban pigs and vitrified in micro‐drops. Oocyte morphology, lipid content, post‐warming survival, nuclear maturation, and embryo development were compared to those of oocytes from commercially slaughtered Landrace × Large white hybrid pigs. The size of oocytes in the two breeds was similar. However, significantly lower amounts of intracellular lipid were detected in Ban oocytes. There was no difference (p > 0.05) between Ban and Landrace × Large white oocytes in percentages of post‐warming survival (93.1 ± 3.4% vs. 70.7 ± 16.7%, respectively) and nuclear maturation after in vitro maturation (80.4 ± 5.1% vs. 90.0 ± 1.3% respectively). Similarly, cleavage (30.8 ± 7.8% vs. 10.3 ± 6.1%, respectively) and blastocyst development rates (9.4 ± 5.0% vs. 0.79 ± 0.79, respectively) were not different (p > 0.05) between vitrified Ban and Landrace × Large white oocytes after in vitro fertilization and embryo culture. In conclusion, high survival and maturation rates were achieved after vitrification of immature Ban oocytes and their cryo‐tolerance was similar to that of Landrace × Large white oocytes, despite the difference in lipid content. We succeeded to generate reasonable rates of blastocysts from vitrified Ban oocytes by in vitro fertilization.     

Rumen fluid,feces, milk,water, feed,airborne dust,and bedding microbiota in dairy farms managed by automatic milking systems

Microbiota of the gut, milk, and cowshed environment were examined at two dairy farms managed by automatic milking systems (AMS). Feed, rumen fluid, feces, milk, bedding, water, and airborne dust were collected and the microbiota on each was assessed by Illumina MiSeq sequencing. The most abundant taxa in feed, rumen fluid, feces, bedding, and water were Lactobacillaceae, Prevotellaceae, Ruminococcaceae, Ruminococcaceae, and Lactobacillaceae, respectively, at both farms. Aerococcaceae was the most abundant taxon in milk and airborne dust microbiota at farm 1, and Staphylococcaceae and Lactobacillaceae were the most abundant taxa in milk and airborne dust microbiota at farm 2. The three most prevalent taxa (Aerococcaceae, Staphylococcaceae, and Ruminococcaceae at farm 1 and Staphylococcaceae, Lactobacillaceae, and Ruminococcaceae at farm 2) were shared between milk and airborne dust microbiota. Indeed, SourceTracker indicated that milk microbiota was related with airborne dust microbiota. Meanwhile, hierarchical clustering and canonical analysis of principal coordinates demonstrated that the milk microbiota was associated with the bedding microbiota but clearly separated from feed, rumen fluid, feces, and water microbiota. Although our findings were derived from only two case studies, the importance of cowshed management for milk quality control and mastitis prevention was emphasized at farms managed by AMS.