Different screening tests and milk somatic cell count for the prevalence of subclinical bovine mastitis in Bangladesh.

Identification of cows with subclinical mastitis (SCM) is an important tool for sustainable dairying and implementing effective mastitis control strategies. A total of 892 quarters milk samples from 228 lactating cows were screened by California mastitis test (CMT), White side test (WST), Surf field mastitis test (SFMT), and somatic cell count (SCC) to study the prevalence of bovine SCM in some selected areas of Bangladesh. Out of 228 cows, 148 (64.9%), 138 (60.5%), 132 (57.9%), and 164 (71.9%) were found positive for SCM by CMT, WST, SFMT, and SCC, respectively. The prevalence of bovine SCM was diagnosed 45.7, 40.2, 36.6, and 29.6% in Chittagong, Sirajgonj, Mymensingh, and Gazipur districts, respectively, based on a combination of all tests. The overall quarter-wise prevalence of SCM was 45.7, 43.5, 41.2, and 55.0% for CMT, WST, SFMT, and SCC. Single quarters and left front quarters were more prone to SCM (P < 0.05). Friesian crossbred cows (56.4%), BCS 2.0-2.5 (55.4%), and parity 4-6 (52.4%), the late lactation stage (5-8 months; 64.7%) and high yielding cows (16-20 L/day; 65.3%) were more susceptible to SCM (P < 0.05). The sensitivity of the CMT, WST, SFMT, and SCC was 65.8, 57.9, 51.0, and 82.5%; specificity 76.2, 72.4, 69.5, and 89.4%; percentage accuracy 70.0, 64.8, 59.9, and 85.2%; positive predictive value 75.2, 69.8, 64.9, and 92.7%, respectively. The categories of CMT reactions were strongly correlated with SCC (P < 0.05). Kappa value of SCC was higher than that of other tests (SCC>CMT>WST>SFMT). Thus, CMT was concluded to be the most accurate (r = 0.782) field diagnostic test after laboratory test like SCC (r = 0.924). However, the use of any single test may not be reliable in diagnosing SCM, while the result of CMT supported by SCC might be used effectively to pinpoint diagnosis of SCM in dairy animals than alone.

Supplementation of insulin-transferrin-selenium to embryo culture medium improves the in vitro development of pig embryos.

Insulin, transferrin and selenium (ITS) supplementation to oocyte maturation medium improves the post-fertilization embryonic development in pigs. ITS is also commonly used as a supplement for the in vitro culture (IVC) of embryos and stem cells in several mammalian species. However, its use during IVC of pig embryos has not been explored. This study investigated the effect of ITS supplementation to IVC medium on the in vitro development ability of pig embryos produced by parthenogenetic activation (PA), in vitro fertilization (IVF) or somatic cell nuclear transfer (SCNT). We observed that ITS had no significant effect on the rate of first cleavage (P > 0.05). However, the rate of blastocyst formation in ITS-treated PA (45.3 ± 1.9 versus 27.1 ± 2.3%), IVF (31.6 ± 0.6 versus 23.5 ± 0.6%) and SCNT (17.6 ± 2.3 versus 10.7 ± 1.4%) embryos was significantly higher (P < 0.05) than those of non-treated controls. Culture of PA embryos in the presence of ITS also enhanced the expansion and hatching ability (29.1 ± 3.0 versus 18.2 ± 3.8%; P < 0.05) of blastocysts and increased the total number of cells per blastocyst (53 ± 2.5 versus 40.9 ± 2.6; P < 0.05). Furthermore, the beneficial effect of ITS on PA embryos was associated with significantly reduced level of intracellular reactive oxygen species (ROS) (20.0 ± 2.6 versus 46.9 ± 3.0). However, in contrast to PA embryos, ITS had no significant effect on the blastocyst quality of IVF and SCNT embryos (P > 0.05). Taken together, these data suggest that supplementation of ITS to the IVC medium exerts a beneficial but differential effect on pig embryos that varies with the method of embryo production in vitro.

Draft genome sequencing of Pediococcus pentosaceus strains isolated from cow milk.

We sequenced the genomes of Pediococcus pentosaceus strains MBBL4 and MBBL6, isolated from raw milk samples of healthy cows. The draft genomes of the MBBL4 and MBBL6 were 1,896,831 bp and 1,849,397 bp, respectively, and were fragmented into 58 and 42 contigs, with coverages of 118.2× and 128.7×, respectively.

Genomic features and pathophysiological impact of a multidrug-resistant Staphylococcus warneri variant in murine mastitis.

Non-aureus staphylococci (NAS) represent a major etiological agent in dairy animal mastitis, yet their role and impact remain insufficiently studied. This study aimed to elucidate the genomic characteristics of a newly identified multidrug-resistant NAS strain, specifically Staphylococcus warneri G1M1F, isolated from murine feces in an experimental mastitis model. Surprisingly, NAS species accounted for 54.35 % of murine mastitis cases, with S. warneri being the most prevalent at 40.0 %. S. warneri G1M1F exhibited resistance to 10 major antibiotics. Whole-genome sequencing established a genetic connection between G1M1F and S. warneri strains isolated previously from various sources including mastitis milk in dairy animals, human feces and blood across diverse geographical regions. Genomic analysis of S. warneri G1M1F unveiled 34 antimicrobial resistance genes (ARGs), 30 virulence factor genes (VFGs), and 278 metabolic features. A significant portion of identified ARGs (64 %) conferred resistance through antibiotic efflux pumps, while VFGs primarily related to bacterial adherence and biofilm formation. Inoculation with G1M1F in mice resulted in pronounced inflammatory lesions in mammary and colon tissues, indicating pathogenic potential. Our findings highlight distinctive genomic traits in S. warneri G1M1F, signifying the emergence of a novel multidrug-resistant NAS variant. These insights contribute to understanding NAS-related mastitis pathophysiology and inform strategies for effective treatment in dairy animals.

Unveiling distinct genetic features in multidrug-resistant Escherichia coli isolated from mammary tissue and gut of mastitis induced mice.

Escherichia coli is one of the major pathogens causing mastitis in lactating mammals. We hypothesized that E. coli from the gut and mammary glands may have similar genomic characteristics in the causation of mastitis. To test this hypothesis, we used whole genome sequencing to analyze two multidrug resistant E. coli strains isolated from mammary tissue (G2M6U) and fecal sample (G6M1F) of experimentally induced mastitis mice. Both strains showed resistance to multiple (>7) antibiotics such as oxacillin, aztreonam, nalidixic acid, streptomycin, gentamicin, cefoxitin, ampicillin, tetracycline, azithromycin and nitrofurantoin. The genome of E. coli G2M6U had 59 antimicrobial resistance genes (ARGs) and 159 virulence factor genes (VFGs), while the E. coli G6M1F genome possessed 77 ARGs and 178 VFGs. Both strains were found to be genetically related to many E. coli strains causing mastitis and enteric diseases originating from different hosts and regions. The G6M1F had several unique ARGs (e.g., QnrS1, sul2, tetA, tetR, emrK, blaTEM-1/105, and aph(6)-Id, aph(3″)-Ib) conferring resistance to certain antibiotics, whereas G2M6U had a unique heat-stable enterotoxin gene (astA) and 7192 single nucleotide polymorphisms. Furthermore, there were 43 and 111 unique genes identified in G2M6U and G6M1F genomes, respectively. These results indicate distinct differences in the genomic characteristics of E. coli strain G2M6U and G6M1F that might have important implications in the pathophysiology of mammalian mastitis, and treatment strategies for mastitis in dairy animals.

Draft genome sequencing of Enterococcus avium strains isolated from bovine mastitis.

We performed whole-genome sequencing of four multidrug-resistant Enterococcus avium strains isolated from milk (4M1), feces (4F1 and 4F2), and farm soil (4S1) of mastitic dairy cows. The draft genomes of E. avium strains 4M1, 4F1, 4F2, and 4S1 were approximately 4.2 Mbp, with 39.1% GC content and 66.5× coverage.

Whole-Genome Sequence of the Multidrug-Resistant Staphylococcus warneri Strain G1M1F, Isolated from Mice with Mastitis.

We sequenced the genome of Staphylococcus warneri G1M1F, a multidrug-resistant strain isolated from fecal samples of mice with induced mastitis. The complete genome of G1M1F consists of one chromosome of 2,504,515 bp and two plasmid replicons of 28,679 and 8,615 bp; it comprises 32.7% GC content, with 60× genome coverage.

Whole-Genome Sequence of Multidrug-Resistant Klebsiella pneumoniae MNH_G2C5, Isolated from Bovine Clinical Mastitis Milk.

Klebsiella pneumoniae is one of the most common and important mastitis-causing bacteria, and strain MNH_G2C5 was isolated from the milk of a cow suffering from clinical mastitis in a dairy farm of the Gazipur district of Bangladesh. The MNH_G2C5 genome was estimated to be 4,589,728 bp, with 65.5% genome coverage.

Draft genome sequence of a multidrug-resistant Klebsiella pneumoniae fecal isolate from a cow with clinical mastitis.

Klebsiella pneumoniae is one of the most important mastitis-causing pathogens. The multidrug-resistant K. pneumoniae strain MNH_G2C5F was isolated from the feces of a cow with clinical mastitis. The MNH_G2C5F strain had a genome size of 5,381,832 bp (85.0× coverage) and typed as sequence type 273 (ST273).

Whole-Genome Sequence of Multidrug-Resistant Escherichia coli Strains Isolated from Mice with Mastitis.

We sequenced the genomes of Escherichia coli isolates G2M6U and G6M1F, two multidrug-resistant strains that were isolated from mammary tissue and fecal samples, respectively, from mice with induced mastitis. The complete genomes of G2M6U and G6M1F consist of chromosomes of 4.4 Mbp and 4.6 Mbp, respectively.

Antibiogram and virulence profiling reveals multidrug resistant Staphylococcus aureus as the predominant aetiology of subclinical mastitis in riverine buffaloes.

BACKGROUND: Staphylococcus spp. are the major causal agents of mastitis in dairy animals worldwide leading to profound economic losses and public health threats. Recently, Staphylococcus aureus has emerged as a multidrug resistant and zoonotic pathogen. This study aimed to characterize S. aureus in subclinical mastitis (SCM) milk samples of riverine buffaloes in Bangladesh through antibiogram and virulence gene(s) profiling, and 16S rRNA gene sequencing. METHOD: We characterized S. aureus in SCM milk samples (N = 500) of riverine buffaloes through antibiogram and virulence gene(s) profiling, and 16S rRNA gene sequencing. RESULTS: Out of 500 milk samples tested, 188 (37.6%) were found positive for SCM. From 188 SCM samples, 291 isolates were obtained with a prevalence of S. aureus in 37.4% (109/291) isolates. Phylogenetic analysis revealed the evolutionary divergence of S. aureus isolates in bubaline SCM milk samples. The antibiogram profiling showed that about 96.0% S. aureus isolates were multidrug resistant (MDR). Notably, 29 and 16 isolates harboured methicillin-resistant (mecA) and panton-valentine leucocidin (pvl) genes, respectively, and 46 plasmid-bearing isolates were MDR. Nine Staphylococcal enterotoxins (SEs/SEls) including sea (11.9%), sec (7.4%), sed (4.6%), seg (3.7%), and seh (3.7%) were detected with 72.48% toxinotypes comprising a single gene. CONCLUSION: This study therefore suggests S. aureus as the single-most aetiology (∼37.0%) of SCM in riverine buffaloes, and emergence of MDR, enterotoxin producing, and virulent S. aureus strains could impose potential threats to animal welfare and public health.

Spirulina ameliorates arsenic induced reproductive toxicity in male rats.

Spirulina (Spirulina platensis), has numerous health benefits including antioxidant, immunomodulatory, and anti-inflammatory activities, works against heavy metal toxicity, and is often used as a food supplement in human, animals, birds and fishes. This study aimed to evaluate the protective ability of the dietary spirulina against the toxic effects of inorganic arsenic (iAs) on male reproductive parameters in rats. Seventy-two mature Long-Evans male rats, dividing into six groups (T0, T1, T2, T3, T4 and T5) (12 rats/group) were included in this study. The T3, T4 and T5 group rats were treated with three consecutive doses (1.0 g, 1.5 g and 2.0 g/kg feed) of spirulina in feed along with 3.0 mg NaAsO2/kg body weight (BW) in drinking water (DW) daily for 90 days. Each rat of group T1 received NaAsO2 (3.0 mg/kg BW) in DW, and those of T2 group were fed with spirulina (2.0 g/kg feed) daily for 90 days. The rats of group T0 served as the control with normal feed and water. Total arsenic (tAs) contents, reproductive parameters (testicular weight, sperm motility and morphology), and histological changes in the testicles were evaluated in these rats. Arsenic dosing significantly (p=0.003, Kruskal-Wallis test) increased the tAs contents in the testicles, decreased testes weight, sperm morphology and motility compared to the controls. The effect of arsenic dosing was also evidenced by the histological changes like decreased germinal layers in the seminiferous tubules of the treated rats. Moreover, dietary spirulina (2.0 g/kg feed) supplementation significantly (p=0.011, Kruskal-Wallis test) lowered tAs contents in testicles and increases testes weights, sperm motility and morphology. Therefore, spirulina can be used as an effective dietary supplement to ameliorate the adverse effects of arsenic induced reproductive toxicities. However, further study is required to elucidate the underlying molecular mechanisms of reduction of arsenic induced reproductive toxicity by spirulina.

Lyophilized somatic cells direct embryonic development after whole cell intracytoplasmic injection into pig oocytes.

The study investigated the feasibility of lyophilization for long-term preservation of somatic cells and embryonic development after whole cell intracytoplasmic injection (WCICI) into enucleated pig oocyte. Confluent cultured porcine fetal fibroblast (pFF) cells were lyophilized and stored at 4°C for at least 6 months. Results showed that compared to non-lyophilized control cells, lyophilized cells had drastically reduced cellular viability (P<0.01). WCICI of reconstituted lyophilized cells could support complete embryonic development. However, the rates of cleavage (64.7±2.7 vs. 43.5±4.7%) and blastocyst formation (18.2±0.6 vs. 10.2±1.6%) were lower than that of control (P<0.05). Total nuclei number per blastocyst (30.4±4.5 vs. 25.2±4.7) and intensity of acetylation at histone H3 (AcH3) protein (55.9±3.5 vs. 53.3±3.8) did not differ (P>0.05). The development ability of embryos, produced from lyophilized somatic cells, was further increased (19.5±2.4 vs. 10.2±1.6%; P<0.05) by treatment with trichostatin A (TSA) for 24h post-activation. These TSA-treated embryos also had AcH3 level comparable with in vitro fertilized embryos (63.1±3.2 vs. 69.9±1.3). In conclusion, our results suggest that lyophilized somatic cells can direct embryonic development up to blastocyst stage after WCICI into pig oocytes. Treatment of embryos, produced from lyophilized somatic cells, with TSA can further increase their in vitro developmental potential.

Economic benefit in repeat breeder cows using intrauterine infusion of penicillin and estrus synchronization followed by timed artificial insemination.

OBJECTIVE: Until recently, management of repeat breeding in cattle remains a major problem to dairy farmers. This study was carried out to improve the fertility in cows, those did not conceive after three or more consecutive services. MATERIALS AND METHODS: Twenty-three repeat breeding cows were selected from the Central Cattle Breeding Station and Dairy Farm (CCBS & DF), Savar, Dhaka, Bangladesh. Data of another 23 repeat breeding cows that conceived after four or more services were collected from the same farm as controls. The repeat breeders were synchronized for estrus with two injections of PGF2α 11 days apart and timed AI (TAI) was performed. RESULTS: Seventeen of 23 cows had uterine infections. Intrauterine infusion of penicillin daily for three successive days from the following day of the first PGF2α injection resulted in 94.1% (16/17) recovery. Of 23 treated cows, four with estrus synchronization and TAI, and one with only AI after hormone treatment were detected pregnant by per rectal examination of the genital tract. By this pregnancy, the treated cows have advanced average of 131.6 days calving interval and days open, and thereby saved neat US $3,045.3 in comparison to control cows. Control group cows incurred losses of US $15,134.0 compared with average days open of the treated pregnant cows. CONCLUSION: Intrauterine infusion of penicillin can successfully recover the uterine infections, and estrus synchronization followed by TAI resulted in pregnancy in a proportion of repeat breeder cows with economic benefit that had a uterine infection.

A survey of Japanese quail (Coturnix coturnix japonica) farming in selected areas of Bangladesh.

AIM: To investigate the status, problems and prospects of Japanese quail (Coturnix coturnix japonica) farming in selected areas of Bangladesh. MATERIALS AND METHODS: The study was conducted in 14 districts of Bangladesh, viz., Dhaka, Narayanganj, Munshiganj, Mymensingh, Netrakona, Faridpur, Jessore, Khulna, Satkhira, Kushtia, Bogra, Naogaon, Comilla, and Sylhet during the period from July 2011 to June 2012. A total of 52 quail farmers were interviewed for data collection using a structured questionnaire. Focus group discussions were also carried out with unsuccessful farmers and those want to start quail farming. Workers of quail farms, quail feeds and medicine suppliers, quail eggs and meat sellers were also interviewed regarding the issue. RESULTS: Out of 52 farms, 86.5% were operated by male, 67.3% farmers did not receive any training and 92.3% farmers had no earlier experience of quail farming although 58.0% farmers primary occupation was quail farming. Most of the farms (63.4%) were mixed in type having ≤5000 birds of two or three varieties. About 80.7% farms were operated separately round the year with no other poultry and 83.0% farmers wanted to expand their farming. The average pullet weight 145.0±0.12, 110.0±0.07, 120.0±0.22, and 128.0±0.17 g; age at the first lay 46.0±0.04, 42.0±0.31, 42.0±0.09, and 45.2±0.05 days; rearing period 15.0±0.01, 12.0±0.14, 15.0±0.32, and 15.2±0.18 months; culling period 15.5±0.14, 13.0±0.06, 15.0±0.03, and 15.4±0.26 months were for layer, parent stock, hatchery, and mixed farms, respectively. Most of the layer farms had an average egg production of ≤5000/day and net profit BDT 0.75/egg. However, an average number of birds, hatchability and net profit per day-old-chick were ≤5000, 76.8% and BDT 2.75, respectively, in the hatchery. Broiler quails were sold at 30 days with mean weight of 110.8 g and net profit BDT 9.02/bird. The major constraints of quail farming were higher feed price, outbreak of endemic diseases, lack of proper knowledge, farmers training, proper market access, difficulties of parent stock collection, inadequate biosecurity practices, and limited access to veterinary care. Thus, a proper training on quail farming, bio-security management, and government subsidy on feeds could make quail farming sustainable in Bangladesh. CONCLUSIONS: The study concludes that Japanese quail farming has enormous potentiality and could be an alternative to chicken farming particularly in providing gainful employment, supplementary income and as a valuable source of meat and egg, quail farming should be encouraged and promoted in Bangladesh.

Transgenic chicken, mice, cattle, and pig embryos by somatic cell nuclear transfer into pig oocytes.

This study explored the possibility of producing transgenic cloned embryos by interspecies somatic cell nuclear transfer (iSCNT) of cattle, mice, and chicken donor cells into enucleated pig oocytes. Enhanced green florescent protein (EGFP)-expressing donor cells were used for the nuclear transfer. Results showed that the occurrence of first cleavage did not differ significantly when pig, cattle, mice, or chicken cells were used as donor nuclei (p>0.05). However, the rate of blastocyst formation was significantly higher in pig (14.9±2.1%; p<0.05) SCNT embryos than in cattle (6.3±2.5%), mice (4.2±1.4%), or chicken (5.1±2.4%) iSCNT embryos. The iSCNT embryos also contained a significantly less number of cells per blastocyst than those of SCNT pig embryos (p<0.05). All (100%) iSCNT embryos expressed the EGFP gene, as evidenced by the green florescence under ultraviolet (UV) illumination. Microinjection of purified mitochondria from cattle somatic cells into pig oocytes did not have any adverse effect on their postfertilization in vitro development and embryo quality (p>0.05). Moreover, NCSU23 medium, which was designed for in vitro culture of pig embryos, was able to support the in vitro development of cattle, mice, and chicken iSCNT embryos up to the blastocyst stage. Taken together, these data suggest that enucleated pig oocytes may be used as a universal cytoplast for production of transgenic cattle, mice, and chicken embryos by iSCNT. Furthermore, xenogenic transfer of mitochondria to the recipient cytoplast may not be the cause for poor embryonic development of cattle-pig iSCNT embryos.

3-Hydroxyflavone improves the in vitro development of cloned porcine embryos by inhibiting ROS production.

UV-irradiation of oocytes during enucleation and serum starvation of donor cells during cell cycle synchronization may compromise the development competence of cloned embryos through excessive generation of reactive oxygen species (ROS). Here, we show that 3-hyroxyflavone (a flavonoid having hydroxyl group at 3 carbon position) inhibits UV- and serum starvation-induced ROS production in oocytes and donor cells, respectively, and thereby improves the in vitro development of cloned porcine embryos (p<0.05). In a parthenogenetic model, UV-irradiation for 5 sec or more was found to reduce the in vitro development and quality of the embryo, which could be rescued by their culture in the presence of 3-hydroxyflavone. The rescuing effect of 3-hydroxyflavone was associated with significant reduction in ROS level (14.4±1.0 vs. 47.1±6.7), increase in ERK signaling molecules by 2.1-fold, and decrease in Caspase3 expression by 3.2-fold. Culture of donor cells (18.5±1.4 vs. 13.0±1.7%) or cloned embryos (20.6±1.1 vs. 12.2±1.1%) in the presence of 3-hydroxflavone also increased (p<0.05) the rates of blastocyst formation in cloned embryos produced by the nuclear transfer of serum-starved donor cells into recipient cytoplasts exposed to UV-irradiation during the enucleation step. Importantly, both parthenotes and cloned embryos cultured in the presence of 3-hydroxyflavone had significantly increased ability to expand, and contained a higher number of cells than those of the control group (p<0.05). These results suggest that 3-hydroxyflavone may be useful for improving the in vitro developmental potential of cloned embryos through inhibition of ROS production induced by the UV-irradiation of oocyte and/or the serum starvation of donor cells.

Possible involvement of Class III phosphatidylinositol-3-kinase in meiotic progression of porcine oocytes beyond germinal vesicle stage.

Phosphatidylinositol-3-kinases (PI3Ks) play pivotal roles in meiotic progression of oocytes from metaphase I to metaphase II stage. Using a Class III-specific inhibitor of PI3K, 3-methyladenine (3MA), this study shows that Class III PI3K may be essential for meiotic progression of porcine oocytes beyond germinal vesicle (GV) stage. Treatment of immature porcine oocytes with 3MA for 22-42 h arrested them at the GV stage, irrespective of the presence or absence of cumulus cells. Furthermore, a significantly high proportion (60.9 ± 13.8%) of 3MA-treated oocytes acquired a nucleolus completely surrounded by a rim of highly condensed chromatin (GV-II stage). The GV-arresting effect of 3MA was, however, completely reversible upon their further culture in the absence of 3MA for 22 h. When cumulus-oophorus-complexes (COCs), arrested at the GV stage for 22 h by 3MA, were further cultured for 22 h in the absence of 3MA, 96.1 ± 1.5% of oocytes reached the MII stage at 42 h of IVM and did not differ from non-treated control oocytes with respect to their ability to fertilize, cleave and form blastocyst (P > 0.05) upon in vitro fertilization (IVF) or parthenogenetic activation (PA). These data suggest that 3MA efficiently blocks and synchronizes the meiotic progression of porcine oocytes at the GV stage without affecting their ooplasmic maturation in terms of post-fertilization/activation in vitro embryonic development. Our data also provide indirect evidence for the likely participation of Class III PI3K in meiotic maturation of porcine oocyte beyond the GV stage.

Effect of 3-hydroxyflavone on pig embryos produced by parthenogenesis or somatic cell nuclear transfer.

This study evaluated the effect of 3-hydroxyflavone (a flavonoid having hydroxyl group at 3 carbon position) on embryos using parthenogenetic activation (PA) and cloned pig embryos as model system. There was no evidence for embryo toxicity of 3-hydroxyflavone in a wide concentration range of 1-100 µM. On the contrary, 3-hydroxyflavone significantly improved the in vitro development and quality of PA embryos that was associated with the activation of ERK signaling molecules and reduction in Caspase 3 expression. Furthermore, 3-hydroxyflavone rescued the in vitro development and embryo quality of in vitro aged oocytes by inhibiting ROS activity and activating ERK signaling. The beneficial effects of 3-hydroxyflavone on PA embryos were consistent both in PVA- and BSA-containing embryo culture medium and in cloned embryos. These results suggest that, contrary to those of other structurally related flavonoid molecules, 3-hydroxyflavone may be useful as a therapeutic drug for improving the developmental potential of aged oocytes in assisted reproductive technologies.

Increasing histone acetylation of cloned embryos, but not donor cells, by sodium butyrate improves their in vitro development in pigs.

Previous studies have demonstrated that increased histone acetylation in donor cells or cloned embryos, by applying a histone deacetylase inhibitor (HDACi) such as trichostatin A (TSA), significantly enhances their developmental competence. However, its effect may vary with the type of HDACi and the target species, with some research showing nonsignificant or detrimental effects of TSA on in vitro and in vivo development of embryos. In this study, we show that sodium salt of butyric acid, a short-chain fatty acid produced naturally in the body by bacterial degradation of dietary fibers in the colon and rectum, increases histone acetylation in pig fibroblast and embryos at a concentration of 1.0 and 5.0 mM, respectively. However, treatment of donor cells with NaBu did not affect the rate of blastocyst formation or embryo quality in terms of histone acetylation and total nuclei per blastocyst (p > 0.05). On the contrary, treatment of cloned pig embryos with NaBu for 4 h significantly enhanced (p < 0.01) the rate of blastocyst formation (18.3 +/- 2.1 vs. 11.2 +/- 3.0%), although the total nuclei number per blastocyst did not differ. More importantly, blastocysts generated from NaBu-treated cloned embryos had increased levels of histone acetylation that was comparable to those of in vitro fertilized (IVF) embryos (36.7 +/- 3.6 vs. 45.9 +/- 2.5). In conclusion, our data suggest that histone hyperacetylation by NaBu treatment of cloned embryos, but not donor cell, enhances their in vitro development up to blastocyst stage.