Melatonin reduces apoptotic cells,SOD2 and HSPB1 and improves the in vitro production and quality of bovine blastocysts

Effects of adding different concentrations of melatonin (10^?7, 10^?9 and 10^?11 M) to maturation (Experiment 1; Control, IVM  + 10^?7, IVM  + 10^?9, IVM  + 10^?11) and culture media (Experiment 2; Control, IVC  + 10^?7, IVC  + 10^?9, IVC  + 10^?11) were evaluated on in vitro bovine embryonic development. The optimal concentration of melatonin (10^?9 M) from Experiments 1–2 was tested in both maturation and/or culture media of Experiment 3 (Control, IVM  + 10^?9, IVC  + 10^?9, IVM /IVC  + 10^?9). In Experiment 1, maturated oocytes from Control and IVM  + 10^?9 treatments showed increased glutathione content, mitochondrial membrane potential and percentage of Grade I blastocysts (40.6% and 43%, respectively). In Experiment 2, an increase in the percentage of Grade I blastocysts was detected in IVC  + 10^?7 (43.5%; 56.7%) and IVC  + 10^?9 (47.4%; 57.4%). Moreover, a lower number and percentage of apoptotic cells in blastocysts were observed in the IVC  + 10^?9 group compared to Control (3.8 ± 0.6; 3.6% versus 6.1 ± 0.6; 5.3%). In Experiment 3, the IVC  + 10^?9 treatment increased percentage of Grade I blastocysts with a lower number of apoptotic cells compared to IVM /IVC  + 10^?9 group (52.6%; 3.0 ± 0.5 versus 46.0%; 5.4 ± 1.0). The IVC  + 10^?9 treatment also had a higher mRNA expression of antioxidant gene (SOD 2) compared to the Control, as well as the heat shock protein (HSPB 1) compared to the IVM  + 10^?9. Reactive oxygen species production was greater in the IVM /IVC  + 10^?9 treatment group. In conclusion, the 10^?9 M concentration of melatonin and the in vitro production phase in which it is used directly affected embryonic development and quality.     

Efficacy of an orally administered modified-live porcine-origin rotavirus vaccine against postweaning diarrhea in pigs

A commercially available, porcine-origin rotavirus vaccine was evaluated for efficacy against postweaning diarrhea due to rotavirus infection in pigs. Weight gains were compared at 5 intervals after weaning. Visual scoring was used to evaluate fecal consistency. Rectal swab specimens were cultured for hemolytic E coli and evaluated for rotaviral antigen by use of enzyme-linked immunosorbent assay. Milk from dams and sera from pigs and dams were evaluated for rotavirus-neutralizing antibodies by use of a plaque-reduction test. Significant differences between vaccinates and controls were not found in the determinants evaluated. Selected rotavirus-positive fecal and rectal swab specimens were examined for double-stranded (ds) RNA by use of direct electropherotyping, and the results were compared with the dsRNA pattern of rotavirus propagated from the vaccine. Only electropherotypes typical of field strain virus were found in the fecal and rectal swab specimens evaluated. Sera from guinea pigs and from a gnotobiotic pig immunized against the field strain rotavirus neutralized Ohio State University strain rotavirus (homologous to the vaccine rotavirus strain), but did not neutralize the Gottfried strain of rotavirus. This indicated that, although the dsRNA electropherotypes of the field and vaccine strains of the virus were different, the serotypes were similar, if not identical.     

Energy and protein metabolism in pregnant sows fed two levels of dietary protein

The present study was performed to quantify the energy and nutrient metabolism of pregnant sows fed high (HP) or low (LP) dietary protein [18.3 vs. 13.5% of dry matter (DM)]. A total of nine sows (four on HP and five on LP diet) were subjected to balance and respiration trials four times during their second pregnancy (approximately on days 30, 61, 80 and 104 of gestation). The digestibility of protein (83.0 vs. 79.9) (p < 0.01) and energy (84.9 vs. 83.7%) (p < 0.05) was higher for the HP diet. Daily intake of metabolizable energy (ME) and retained energy (RE) were similar for the two groups, with an average of 28.37 MJ ME and 3.94 MJ RE, respectively. Heat production (HE) measured according to the respiratory quotient (RQ) and carbon-nitrogen (CN) method was similar (464 vs. 454 kJ/kg 0.75/day, respectively). Sows fed HP retained more energy in protein (3.33 vs. 2.00 MJ/day) (p < 0.001) and tended to retain less energy in fat (1.59 vs. 2.50 MJ/day) than LP sows. Retained nitrogen (N) (22.3 vs. 13.4 g/day) (p < 0.001) and utilization of N (retained/digested) (45.2 vs. 38.1%) was higher for HP sows compared with LP sows. In late pregnancy, retained N, retained fat, HE and oxidation of carbohydrates increased, while oxidation of fat was reduced to zero. In conclusion, both diets provided adequate N for retention in maternal tissue and conception products. In spite of the lower utilization of N in LP sows, the N excretion was depressed by 5.6 g/day compared with HP sows, because of the lower N intake.     

Interactions between dietary fatty acids and hepatic gene expression in livers of pigs during the weaning period

The aim of the present study was to evaluate the impact of dietary fatty acids (FA) during the weaning period on expression of genes involved in the oxidation and metabolism of FA (peroxisome proliferator-activated receptor (PPAR-), stearoyl-CoA-desaturase (SCD), Δ6-desaturase (D6D), acetyl CoA carboxylase (ACC) and fatty acid synthase (FAS)). Liver samples were obtained from littermates, either on day 28 of age just before weaning, or at day 56 after the 4 weeks ad lib. provision of 5% of either animal fat, fish oil or sunflower oil. In conclusion, genes involved in the regulation of FA conversion (SCD, D6D) were influenced by the n-6 to n-3 ratio, whereas the FA oxidation, as indicated by the expression of PPAR-, was highly likely regulated by the hepatic ratio between mono- and poly-unsaturated FA. Furthermore, weaning and/or age affected the hepatic expression of genes involved in FA synthesis and conversion, but not the expression of PPAR-.     

Liver biopsy techniques for adult horses and neonatal foals to assess copper status

Objective To evaluate standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals, as techniques for obtaining tissue for assessment of copper status. The techniques were evaluated with respect to ease of use and effect on the animal.
Procedure Twenty of 24 Thoroughbred mares and 21 of their foals were biopsied. The animals were part of a larger study of the effect of copper supplementation on copper status and the prevalence of developmental orthopaedic disease. Livers were also collected from unrelated horses and sampled to investigate the variability in the distribution of copper in liver tissue.
Result The biopsy technique caused no lasting effect on the mares, but there was an increased risk of viscus penetration associated with taking multiple biopsy cores. The use of ultrasonography to scan the target area for the liver identified four cases that were not appropriate candidates for liver biopsy, because of large intestine being located in the biopsy area. In the foals there were no serious postoperative adverse effects, nor was there any evidence of problems caused by the procedure when the abdomen was examined post-mortem at 5 months of age. In livers collected to investigate the variability of copper concentration, copper appeared to be relatively evenly distributed through the liver.
Conclusion Standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals are convenient procedures for obtaining liver tissue for assessing copper status in horses. The use of ultrasound to identify liver tissue is recommended, especially in older mares.     

Role of phospholipase A2 in the induction of drip loss in porcine muscle

The role of phospholipase A2 in the induction of drip loss from pig muscle has been investigated. In samples from porcine M. longissimus dorsi, total PLA2 activity as well as mRNA and protein levels of the group VIA iPLA2 (iPLA2-VIA) increased during the initial 4 h post-mortem period. Morphological studies of porcine muscle showed that at 4 h post-mortem, gaps had formed between muscle fibers and that the sarcolemma membrane borders appeared blurred. At the same time iPLA2-VIA protein levels were increased inside muscle fibers and at the sarcolemma. iPLA2-VIA mRNA abundance in samples from different breeds of pigs with variations in drip loss revealed no clear correlation between drip loss level and iPLA2-VIA expression. Together, these data indicate that during the post-mortem period, iPLA2-VIA expression and activity is increased at the muscle fiber membranes. PLA2 activity may affect membrane permeability and consequently the progression of drip formation in porcine muscle.     

Rhodococcus equi-associated osteomyelitis in foals

Two cases of Rhodococcus equl infection in foals are described, in which osteomyelitis was a feature. Because rhodococcal infection is usually low grade and chronic, and because the signs of early metaphysitis can be subtle, any articular or periarticular swelling in a foal from a farm with a history of rhodococcosis should be strongly suspected to be associated with R equl until proven otherwise.     

Immune response of pregnant cows to bovine rotavirus immunization

Fifteen pregnant Holstein cows were freely assigned to 3 experimental groups (5 cows in each group). Cows in group I were inoculated IM and intramammarily (IMm) with Ohio Agricultural Research and Development Center (OARDC) tissue culture-propagated modified-live Nebraska calf diarrhea bovine rotavirus with added adjuvant (OARDC vaccine-immunized cows). Group II cows were given IM injections of a commercial modified-live rotavirus-coronavirus vaccine (commercial vaccine-immunized cows), and the remaining 5 cows were noninoculated controls (group III). Rotavirus antibody in colostrum and milk was mainly associated with immunoglobulin (Ig)G1, and less so with IgG2, IgA, and IgM, as analyzed by the enzyme-linked immunosorbent assay (ELISA), using monospecific anti-bovine IgG1, IgG2, IgM, and IgA sera. In serum, the rotavirus antibody was distributed almost equally between IgG1 and IgG2. The same relationships appeared in both immunized and nonvaccinated cows. All OARDC vaccine-injected cows had virus-neutralization (VN) and ELISA IgG1 rotavirus antibody titers in serum and mammary secretions at significantly increased levels (at least 100-fold; P less than 0.05) compared with the titers in groups II (commercial vaccine-immunized cows) and III (controls). Serum, colostrum, and milk antibody titers from these latter 2 groups did not differ statistically. The ELISA IgG2, IgA, and IgM rotavirus antibody titers also were significantly greater in mammary secretions from OARDC vaccine-immunized cows than in groups II and III cows. There was a high correlation between ELISA IgG1 and VN rotavirus antibody titers for all samples tested (r = 0.97, P less than 0.001), but ELISA IgG1 antibody titers were consistently higher than VN titers. The ELISA IgG1 and VN antibody titers of milk samples collected from cows 30 days after parturition were higher from the OARDC vaccine-immunized cows (ELISA IgG1, geometric mean titer (GMT) = 3,511; VN GMT = 1,689) than were titers from the group II cows (ELISA IgG1 GMT = 39; VN GMT = 33) or group III cows (ELISA IgG1 GMT = 21; VN GMT = 19). These results indicate that IM plus IMm immunization of pregnant cows, using modified-live bovine rotavirus with added adjuvant, may significantly enhance serum, colostrum, and milk rotavirus antibody titers, whereas IM vaccinal inoculation of pregnant cows with a commercial modified-live rotavirus-coronavirus vaccine may not.     

Rotavirus as a cause of diarrhea in pigs.

A rotavirus (reovirus-like agent) was associated with diarrheal diseases occurring in 1- to 4-week-old suckling pigs in 8 herds and in weaned pigs in 2 herds. Transmissible gastroenteritis virus was also detected in 2 of these herds, as was enteropathogenic Escherichia coli in 5 herds. Morbidity was generally greater than 80% in pigs of the affected age group within these herds, and mortality from diarrhea ranged from 7 to 20%. The disease due to rotavirus in suckling pigs appeared similar to the syndrome commonly referred to as milk scours, white scours, or 3-week scours. Diarrhea and villous atrophy, resembling that seen in transmissible gastroenteritis, occurred in naturally infected pigs and in gnotobiotic pigs experimentally infected with rotavirus. Diagnosis was accomplished by immune electron microscopy of intestinal contents and by immunofluorescent staining of enterocytes. A massive infection of enterocytes with rotavirus was demonstrated by immunofluorescence, which helps explain the pathogenesis of this disease. The apparent rarity of clinical rotaviral infections in suckling pigs greater than 7 days old is probably due to the acquisition of passive immunity from immune sows.     

Cell culture propagation of porcine rotavirus (reovirus-like agent).

Two isolates of porcine rotavirus (reovirus-like agent) were isolated and passaged in primary procine kidney cell cultures. Viral infectivity for cells was monitored by immunofluorescence because viral cytopathic effect was moderate. Successful passage of virus in cell culture required that viral suspensions obtained from infected cell cultures be treated with pancreatin prior to inoculation onto cell monolayers. Porcine rotavirus passage in cell culture also was accomplished, using trypsin treatments in lieu of pancreatin treatments. Porcine rotavirus passaged 10 times in cell culture infected gnotobiotic pigs and caused diarrhea. Gnotobiotic pigs that recovered from this infection were resistant to challenge exposure with porcine rotavirus but were susceptible to challenge exposure with transmissible gastroenteritis virus. As determined by immunofluorescent cross reactions, porcine rotavirus was found to be antigenically related to the human and bovine rotaviruses but not to reovirus type 3 or to transmissible gastroenteritis virus.