Relationship among ovarian follicular status,developmental competence of oocytes,and anti‐Müllerian hormone levels: A comparative study in Japanese wild boar crossbred gilts and Large White gilts

The aim of this study was to investigate the ovarian follicular development, developmental competence of oocytes, and plasma anti‐Müllerian hormone (AMH) levels of Japanese wild boar crossbred (wild hybrid) gilts, whose litter size is inferior to that of European breeds. Ovary and plasma samples were collected from two different breeds of gilts (wild hybrid and Large White breeds). The ovaries from the wild hybrid gilts had a lower average numbers of secondary follicles and vesicular follicles in ovarian cross‐sections and of good quality oocytes collected from ovarian follicles as compared with those from Large White gilts (p < 0.05). The development rate to the blastocyst stage of good quality oocytes after in vitro maturation, fertilization and culture was also lower (p < 0.05) in wild hybrid gilts than in Large White gilts. Plasma AMH levels with >0.16 ng/ml were detected in 8.3% of the examined wild hybrid gilts and 33% of the Large White gilts. These results indicate that the low reproductive performance of wild hybrid breed may result in part from low numbers of vesicular follicles and good quality oocytes, and low developmental competence of oocytes. Moreover, plasma AMH levels may support low number of vesicular follicles in ovaries of wild hybrid gilts.     

Developmental ability of oocytes retrieved from Meishan neonatal ovarian tissue grafted into nude mice

Ovarian xenografting makes it possible to obtain oocytes with fertilization ability from immature pigs of Western breeds. In this study, we applied these methods to the Meishan, an indigenous Chinese pig breed, and investigated the developmental competence of oocytes grown in their neonatal tissue after grafting into nude mice. First, mice harboring neonatal ovarian tissue were infused with follicle stimulating hormone (FSH) (62.5 U/ml) for 13 days starting at 10, 30, and 60 days after vaginal opening (D10‐, D30‐, and D60‐FSH groups, respectively). Development of antral follicles and their oocytes was most enhanced in the D60‐FSH group. For the next step, we examined the in vitro maturation ability of the oocytes recovered from host mice after infusion with FSH at a dose of 62.5 U/ml or 125 U/ml (FSH‐62.5 or ‐125 group) for 13 days starting at 60 days after vaginal opening. Many more oocytes with maturation ability were obtained from the FSH‐125 group. The FSH‐125 mature oocytes were fertilized in vitro, as shown by formation of male and female pronuclei, but did not reach the blastocyst stage. These results indicate that Meishan neonatal ovaries are able to produce oocytes with fertilization ability after being grafted into nude mice.     

Presence of chlorogenic acid during in vitro maturation protects porcine oocytes from the negative effects of heat stress

Chlorogenic acid (CGA) is known to protect oocytes from oxidative stress. Here we investigated the effects of CGA on porcine oocyte maturation under heat stress and subsequent embryonic development after parthenogenetic activation. For in vitro maturation (IVM) at 41.0°C (hyperthermic condition), supplementation of the maturation medium with 50 μM CGA significantly improved the percentage of matured oocytes and reduced the rate of apoptosis relative to oocytes matured without CGA (p < .05). CGA treatment of oocytes during IVM under hyperthermia tended to increase (p < .1) percentage of blastocyst formation after parthenogenesis and significantly increased (p < .05) the total cell number per blastocyst relative to oocytes matured without CGA. For IVM at 38.5°C (isothermic condition), CGA significantly improved the rate of blastocyst development compared with oocytes matured without CGA (p < .05), but did not affect oocyte maturation, apoptosis rate or the number of cells per embryo. Omission of all antioxidants from the IVM medium significantly reduced the rate of oocyte maturation, but the rate was restored upon addition of CGA. These results demonstrate that CGA is a potent antioxidant that protects porcine oocytes from the negative effects of heat stress, thus reducing the frequency of apoptosis and improving the quality of embryos.     

Distribution of Salmonella Serovars and Antimicrobial Susceptibility from Poultry and Swine Farms in Central Vietnam

This study was conducted to estimate the prevalence of Salmonella spp. and their antimicrobial susceptibilities on poultry and swine farms, sampled in 2 regions in Central Vietnam. A total of 67 poultry farms and 46 swine farms were sampled in a period of 5 months (from September 2012 to January 2013). Salmonella spp. was prevalent in 46.3% and 71.7% of poultry and swine farms, respectively. Altogether, 99 non‐typhoidal Salmonella were isolated and the most common serovars were Salmonella Weltevreden (19%), followed by Salmonella Typhimurium (12%) and Salmonella 4,[5],12:i:‐ (11%). Overall, 71 of 99 (72%) Salmonella isolates were resistant to at least one of the 14 antimicrobial agents tested. Both in poultry and swine farms, high levels of resistance were observed for ampicillin, chloramphenicol, ciprofloxacin, sulphamethoxazole and tetracycline. The presence of Salmonella isolates from poultry and swine farms which were resistant to different classes of antimicrobials suggests that alternative control measures to antimicrobials should be implemented. Moreover, an effective policy should be promoted to encourage a prudent use of these agents in animal farming in Vietnam.     

Pharmacokinetics of orally administered phenylbutazone in African and Asian elephants (Loxodonta africana and Elephas maximus)

The pharmacokinetic parameters of phenylbutazone were determined in 18 elephants (Loxodonta africana and Elephas maximus) after single-dose oral administration of 2, 3, and 4 mg/kg phenylbutazone, as well as multiple-dose administrations with a 4-wk washout period between trials. After administration of 2 mg/kg phenylbutazone, mean serum concentrations peaked in approximately 7.5 hr at 4.3 +/- 2.02 microg/ml and 9.7 hr at 7.1 +/- 2.36 microg/ml for African and Asian elephants, respectively, while 3 mg/kg dosages resulted in peak serum concentrations of 7.2 +/- 4.06 microg/ml in 8.4 hr and 12.1 +/- 3.13 microg/ml in 14 hr. The harmonic mean half-life was long, ranging between 13 and 15 hr and 39 and 45 hr for African and Asian elephants, respectively. There was evidence of enterohepatic cycling of phenylbutazone in Asian elephants. Significant differences (P < 0.0001) in pharmacokinetic values occurred between African and Asian elephants for clearance (27.9 and 7.6 ml/hr/kg, respectively), terminal half-life (15.0 and 38.7 hr, respectively), and mean residence time (22.5 and 55.5 hr, respectively) using 2-mg/kg dosages as an example. This suggests that different treatment regimens for Asian and African elephants should be used. There were no apparent gender differences in these parameters for either elephant species.     

Characteristics of two duck farming systems in the Mekong Delta of Viet Nam: stationary flocks and moving flocks, and their potential relevance to the spread of highly pathogenic avian influenza

Ducks are considered to play a major role in the spread of highly pathogenic avian influenza (HPAI) H5N1 in Viet Nam, but detailed information on their management is limited. We distinguished two different systems (1) stationary duck flocks that are not commonly driven to rice fields beyond village boundaries and that are confined overnight on farms and (2) moving duck flocks that are intentionally driven to rice fields beyond village boundaries, that are not returning to home farms for extended periods and that are housed overnight in temporary enclosures in rice paddies. A total of 115 stationary and 22 moving flock farmers were interviewed in 2007 in the Mekong Delta of Viet Nam. Moving duck flocks are larger than stationary flocks, which is indicative of their more commercial production. Moving flock farmers apparently are more aware of HPAI risks than stationary flock farmers, as their flocks are more likely fully vaccinated and have less contact with chickens during scavenging. On the other hand, the spread of HPAI virus between birds might be promoted by moving duck flocks as they repeatedly use transport vehicles and numerous rice paddies for scavenging and are often visited by hatchery owners in the field for purchasing duck eggs. In addition, long distances travelled by moving duck flocks might also result in widespread dissemination of HPAI virus. Further studies are necessary to describe HPAI prevalence and travel patterns of moving duck flocks and to explore the moving duck flock network in detail.     

Digested soybean protein and taurine influence bile acid level,lipase activity,lipid digestibility,and growth performance of pompano (Trachinotus blochii)

Fish Physiology and Biochemistry - This study aimed to examine the effects of dietary digested soybean protein (DSP) and taurine on bile acid (BA) level, lipase activity, lipid apparent...     

Haemonchus contortus (Nematoda: Trichostrongylidae) infection in lambs elicits an unequivocal Th2 immune response

Selection of resistant animals and host immunization have been proposed as alternative methods for the control of gastrointestinal nematode parasites. However, a better knowledge of the mechanisms involved in protective immunity against these parasites is required for the development of optimal strategies. In this study, 3 month old INRA 401 lambs (n = 81) were allocated into three groups: uninfected control, challenged either once (primary-infected animals) or twice (previously-infected animals) with 10,000 Haemonchus contortus L3. Uninfected control and challenged animals were sequentially sacrificed at 3, 7, 15 and 28 days post challenge. In both challenged groups, a clear Th2-oriented immune response was observed in the abomasal lymph node and mucosa. IL-4 and IL-13 mRNA over-expression, recruitment of eosinophils, mast cells and globule leukocytes and production of specific systemic IgG and mucosal IgA were observed earlier in previously-infected animals than in primary-infected ones. At 28 days post infection, no differences between intensities of these responses were observed between the challenged groups. Worm establishment rates were similar in previously-infected and primary-infected lambs. However, reductions of worm development, female fecundity and fecal egg output were observed in previously-infected sheep. We conclude that H. contortus infection in young INRA 401 lambs induced an unequivocal Th2 immune response resulting in the regulation of worm egg production without affecting their establishment.     

Establishment and characterization of a cell line, MCO-Y4, derived from canine mammary gland osteosarcoma

A cell line, MCO-Y4, was established from a mammary gland osteosarcoma of a 16-year-old female mongrel dog. Histopathologically the tumor was composed of osteoblastic cells with an osteoid meshwork and chondroid matrix. The mean doubling time of the cells at the 93rd passage was 32.39+/-4.66 hr. Immunohistochemically, the osteoblastic and chondroblastic cells were positive for bone morphogenetic protein (BMP)-2/4 and BMP receptor (BMPR) II. The cultured cells were spindle in shape during the growth and the confluent phases. No tumor matrix was detected in the culture dish by alcian blue staining or von-Kossa silver impregnation. MCO-Y4 cells on the chamber slides showed intense immunoreactivity for BMP-2/4 and BMPR II. Noggin, an antagonist for BMP-2/4, showed the growth inhibition on MCO-Y4 cells. In addition, fibronectin might be potential for stimulating growth of MCO-Y4 cells. When transplanted into severe combined immunodeficiency mice, the cells formed tumors consisting of solid proliferation of osteoblastic and fibroblastic cells with woven-bone trabeculae. These tumor cells were intensely positive for BMP-2/4 and BMPR II. Our results suggested that the cell line might be useful for studying the role of BMPs in canine osteosarcoma and the mechanism of ossification.