Melatonin Supplementation During In Vitro Maturation and Development Supports the Development of Porcine Embryos

Melatonin has been reported to improve the in vitro development of embryos in some species. This study was conducted to investigate the effect of melatonin supplementation during in vitro maturation (IVM) and development culture on the development and quality of porcine embryos. In the first experiment, when the in vitro fertilized embryos were cultured with different concentrations of melatonin (0, 10, 25 and 50 ng/ml) for 8 days, the blastocyst formation rate of embryos cultured with 25 ng/ml melatonin (10.7%) was significantly increased (p < 0.05) compared to the control embryos cultured without melatonin (4.2%). The proportion of DNA‐fragmented nuclei in blastocysts derived from embryos cultured with 50 ng/ml melatonin was significantly lower (p < 0.05) than that of embryos cultured without melatonin (2.1% vs 7.2%). In the second experiment, when oocytes were cultured in the maturation medium supplemented with different concentrations of melatonin (0, 10, 25 and 50 ng/ml), fertilized and then cultured with 25 ng/ml melatonin for 8 days, there were no significant differences in the rates of cleavage and blastocyst formation among the groups. However, the proportions (2.7–5.4%) of DNA‐fragmented nuclei in blastocysts derived from oocytes matured with melatonin were significantly decreased (p < 0.05) compared to those (8.9%) from oocytes matured without melatonin, irrespective of the concentration of melatonin. Our results suggest that supplementation of the culture media with melatonin (25 ng/ml) during IVM and development has beneficial effects on the developmental competence and quality of porcine embryos.     

Interaction effect of whole wheat feeding and mannanoligosaccharides supplementation on growth performance,haematological indices and caecal microbiota of cockerel chicks

The interaction effect of whole wheat feeding and mannanoligosaccharides supplementation on growth performance, haematological indices and caecal microbiota of cockerel chicks were investigated using 250‐day‐old cockerel chicks previously reared for 7 days pre‐experimental period. Birds were fed with commercial chick mash during the pre‐experimental period. At the expiration of this period, 192 chicks were selected on weight equalization basis and assigned into 24 pens. Each treatment consisted of six pens, while each pen housed eight birds. Four wheat–soya bean‐based experimental diets were formulated in a 2 × 2 factorial arrangement of diets having two wheat forms (ground and whole wheat grain) each supplemented or not with 1 g/kg MOS/kg feed. Whole wheat feeding (irrespective of MOS supplementation) showed reduced (p < 0.05) feed intake. Birds fed whole wheat diet supplemented with MOS recorded the highest (p < 0.01) final live weight, weight gain and the best (p < 0.05) feed conversion ratio. Haemoglobin concentration, packed cell volume and red blood cell count of the chicks were not affected (p > 0.05) by dietary treatment. However, dietary supplementation with MOS resulted in increased (p < 0.05) WBC counts. The caecum content of chicks fed with MOS‐supplemented whole wheat diets recorded the least (p < 0.01) salmonella counts. In conclusion, combination of whole wheat feeding and MOS supplementation showed improved growth performance, gut microbiota and indications of improved health status of cockerel chicks.     

Toxicokinetics and absolute oral bioavailability of melamine in broiler chickens

The objective of this study was to investigate the toxicokinetic characteristics of melamine in broilers due to the limited information available for livestock. Melamine was then administered to broiler chickens at an intravenous (i.v.) or oral (p.o.) dosage of 5.5 mg/kg of body weight, and plasma samples were collected up to 48 h. The concentration of melamine in each plasma sample was analyzed using liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). Melamine was measurable up to 24 h after i.v. and p.o. administration. A one‐compartment model was developed to describe the toxicokinetics of melamine in broilers. Following i.v. administration, the values for the elimination half‐life (t_1/2β), the volume of distribution (V_d), and the clearance (CL) were 4.42 ± 1.02 h, 00.52 ± 0.18 L/kg, and 0.08 ± 0.01 L/h/kg, respectively. The absolute oral bioavailability (F) was 95.63 ± 3.54%. The results suggest that most of the administered melamine is favorably absorbed from the alimentary tract and rapidly cleared by the kidneys in broiler chickens.     

Simultaneous Infection of Pigs and People with Triple‐Reassortant Swine Influenza Virus H1N1 at a U.S. County Fair

Influenza‐like illness was noted in people and pigs in attendance at an Ohio county fair in August 2007. The morbidity rate in swine approached 100% within 1–2 days of initial clinical signs being recognized, and approximately two dozen people developed influenza‐like illness. Triple‐reassortant swine H1N1 influenza viruses were identified in both pigs and people at the fair. The identified viruses (A/Sw/OH/511445/2007, A/Ohio/01/2007, and A/Ohio/02/2007) were similar to H1N1 swine influenza viruses currently found in the U.S. swine population. This case illustrates the possibility of transmission of swine influenza in settings where there is close human/swine interaction.     

Pharmacokinetics of florfenicol in the plasma of Japanese quail

Abstract

AIM: To determine the pharmacokinetics and bioavailability of florfenicol in the plasma of healthy Japanese quail (Coturnix japonica).

METHODS: Sixty-five quail were given an I/V and I/M dose of florfenicol at 30 mg/kg bodyweight (BW). A two-period sequential design was used, with a wash-out period of 2 weeks between the different routes of administration. Concentrations of florfenicol in plasma were determined using high-performance liquid chromatography (HPLC).

RESULTS: A naíve pooled data analysis approach for the plasma concentration-time profile of florfenicol was found to fit a non-compartmental open model. After I/V administration, the mean residence time (MRT), mean volume of distribution at steady state (V_ss), and total body clearance of florfenicol were 12.0 (SD 0.37) h, 8.7 (SD 0.22) L/kg, and 1.3 (SD 0.08) L/h/kg, respectively. After I/M injection, the MRT, mean absorption time (MAT), and bioavailability were 12.3 (SD 0.37) h, 0.2 (SD 0.02) h, and 79.1 (SD 1.79)%, respectively.

CONCLUSIONS: The time for the concentration of florfenicol to fall below the probable effective concentration of 1 µg/ml of approximately 10 h is sufficient for the minimum inhibitory concentration needed for many bacterial isolates. Further pharm acodynamic studies in quail are needed to evaluate a suitable dosage regimen.     

Effects of Astragalus membranaceus on growth performance,carcass characteristics,and antioxidant status of broiler chickens

Abstract

An experiment was conducted using 720 one-day-old Arbor Acres broiler chickens to evaluate the effects of Astragalus membranaceus root powder (AMP), Astragalus polysaccharides (APS) on growth performance, carcass characteristics, and antioxidant enzymes, and metabolites of blood and liver in broiler chickens. The six dietary treatments included a control that was a corn–soybean meal basal diet; basal diet supplemented with 120 mg/kg antibiotic; 350 mg/kg APS; or 5000, 10,000, or 15,000 mg/kg diet of AMP. Supplementation of 10,000 mg/kg AMP increased average daily gain and feed conversion rate of broilers in grower period (22–42 d) and over the entire experiment compared to basic diet. Responses of antioxidant status to dietary APS and AMP varied depending on the age of the broilers. Beneficial effects of AMP on growth and feed utilization of broilers could be obtained by inclusion of AMP at the rate of 10,000 mg/kg diet.     

Porcine circovirus type 2 (PCV2) vaccination reduces PCV2 in a PCV2 and Salmonella enterica serovar Choleraesuis coinfection model

We previously reported that prior porcine circovirus type 2 (PCV2) infection potentiates the severity of clinical signs, lung lesions, and fecal shedding and tissue dissemination of Salmonella enterica serovar Choleraesuis in infected pigs. Here, we evaluated whether PCV2 vaccination is effective in reducing fecal shedding and tissue dissemination of S. Choleraesuis and improving clinical signs associated with PCV2 and S. Choleraesuis infection in 15 Cesarean-derived, colostrum-deprived pigs randomly assigned to 3 groups (n = 5/group). The vaccinated and co-infected (VAC-COINF) group received 2 ml of a commercial PCV2 vaccine at age 3 weeks. The VAC-COINF and co-infected (COINF) groups were inoculated intranasally with PCV2 and S. Choleraesuis at 5 and 7 weeks of age, respectively. The CONTROL group pigs received a similar volume of PBS for sham-vaccination and sham-inoculation. PCV2 vaccination clearly reduced PCV2 DNA load in the serum and postmortem tissue samples and decreased PCV2 antigen levels in tissue samples of the VAC-COINF group. After S. Choleraesuis infection, the incidence of several clinical signs increased in the VAC-COINF group compared to that in the COINF group. The microscopic lung lesions and weight gain, fecal shedding and tissue dissemination of S. Choleraesuis except in the spleen were not significantly different in the VAC-COINF and COINF groups. Thus, PCV2 vaccination reduced PCV2 in the S. Choleraesuis and PCV2 coinfection model and the effects on S. Choleraesuis were minimal.     

Lactogenic hormones stimulate expression of lipogenic genes but not glucose transporters in bovine mammary gland

During the onset of lactation, there is a dramatic increase in the expression of glucose transporters (GLUT) and a group of enzymes involved in milk fat synthesis in the bovine mammary gland. The objective of this study was to investigate whether the lactogenic hormones mediate both of these increases. Bovine mammary explants were cultured for 48, 72, or 96 h with the following hormone treatments: no hormone (control), IGF-I, insulin (Ins), Ins + hydrocortisone + ovine prolactin (InsHPrl), or Ins + hydrocortisone + prolactin + 17β-estradiol (InsHPrlE). The relative expression of β-casein, α-lactalbumin, sterol regulatory element binding factor 1 (SREBF1), fatty acid synthase (FASN), acetyl-CoA carboxylase α (ACACA), stearyol-CoA desaturase (SCD), GLUT1, GLUT8, and GLUT12 were measured by real-time PCR. Exposure to the lactogenic hormone combinations InsHPrl and InsHPrlE for 96 h stimulated expression of β-casein and α-lactalbumin mRNA by several hundred-fold and also increased the expression of SREBF1, FASN, ACACA, and SCD genes in mammary explants (P < 0.01). However, those hormone combinations had no effect on GLUT1 or GLUT8 expression and inhibited GLUT12 expression by 50% after 72 h of treatment (P < 0.05). In separate experiments, the expression of GLUTs in the mouse mammary epithelial cell line HC11 or in bovine primary mammary epithelial cells was not increased by lactogenic hormone treatments. Moreover, treatment of dairy cows with bovine prolactin had no effect on GLUT expression in the mammary gland. In conclusion, lactogenic hormones clearly stimulate expression of milk protein and lipogenic genes, but they do not appear to mediate the marked up-regulation of GLUT expression in the mammary gland during the onset of lactation.     

Epidemiological studies on the expectation of life for cats computed from animal cemetery records

Based on the Chiang's method, the life table for cats was constructed from the death data of 3936 cats. They died in the Kanto area and were buried in an animal cemetery in Tokyo from June 1981 through May 1982. This life table seems to be the first one for domestic pet cats. The expectation of life for cats was 4.2 years at age 0, 5.0 years at age 1, 5.4 years at age 4, 5.3 years at age 5, 3.5 years at age 10, and 2.2 years at age 15. The maximum age at death was 22 years. From age 0 to age 5, the probability of dying for cats was higher than that for dogs, but over 6 years of age it seemed that Gompertz's equation was applicable to this life table for cats. From these results, if the probability of dying for cats at early ages decreases, the fundamental pattern of dying curve for cats seems to be a similar figure of dogs. The life table was constructed for different breeds and localities. Comparing the expectation of life at age 1 (e1) of the two populations divided by breeds or localities, there was significant difference in the e1 among different localities but not among different breeds. These facts suggest the existence of some factors which may influence the life span of cats among different localities.