Phylogenetic analysis of porcine rotavirus in Argentina: increasing diversity of G4 strains and evidence of interspecies transmission

Group A rotaviruses are one of the most frequently detected viral agents associated with neonatal diarrhea in piglets. In order to characterize rotavirus (RV) strains circulating in Argentinean swine, four porcine production farms located in Buenos Aires were studied. RV strains genotyped as P[6]G4, P[6]G8 and P[1]G6 were found in piglets under 30 days of age, without diarrhea. Phylogenetic and sequence analysis of the VP7 gene from G4 strains available in databases, reveals five porcine new lineages (III-VII) and three sublineages (VIIa-VIIc). The G4 porcine Argentinean strains were grouped with a porcine RV strain isolated in Brazil and another RV strain isolated from a child with diarrhea in Mexico, constituting an American lineage (VII). On the other hand, porcine G6 and G8 were closely related to RV's circulating in Argentinean cattle and South-American camelids, respectively. The fact that G4 porcine lineages were epidemiologically related to human strains, and G6 and G8 Argentinean porcine strains were found related to bovine and South-American camelids, respectively, suggests that pigs might play a crucial role as reservoir and generator of newly adapted emerging RV strains for human and other species.     

Rectally Guided or Hysteroscopic Insemination: Is there a difference?

The increasing use of frozen semen, the high cost of a dose of semen from some stallions, and the inability of some stallions to cope with their demand has triggered an incentive to reduce the number of spermatozoa from the traditional 500 PMS to significantly lower numbers per insemination. Two techniques have been described to deposit low sperm numbers in the uterus. Although experimental results have been reported for the rectally guided deep horn insemination (RGDHI) and endoscopic deep horn insemination (EDHI) techniques, little information is available in clinical settings with respect to the results of either method. This article reports on a comparison of the rectally guided insemination and hysteroscopic techniques in a clinical setting over three breeding seasons. Semen frozen in 0.5-mL straws and concentrations of 40 to 200 million per straw was available from 88 stallions whose fertility with frozen semen ranged between 0% and 100%. Of the 2544 inseminations performed 1279 were done by RGDHI, which resulted in a 43% seasonal pregnancy rate compared with 45% for the 1265 inseminations using the EDHI technique. There was an overall, but nonsignificant, advantage for the EDHI technique over the RGDHI and semen usage was slightly lower when using the EDHI procedure. There was no difference in fertility among breeding seasons for either technique. However, fertility of some stallions was increased by increasing the sperm numbers in the inseminates. From these data and results from others, it is evident that lower sperm numbers deposited by rectally guiding a flexible pipette to the tip of the horn or by using an endoscope to deliver the semen will result in acceptable pregnancy rates with frozen semen in commercial settings.     

Antiviral activity of casein and αs2 casein hydrolysates against the infectious haematopoietic necrosis virus,a rhabdovirus from salmonid fish

Salmonid fish viruses, such as infectious haematopoietic necrosis virus (IHNV), are responsible for serious losses in the rainbow trout and salmon‐farming industries, and they have been the subject of intense research in the field of aquaculture. Thus, the aim of this work is to study the antiviral effect of milk‐derived proteins as bovine caseins or casein‐derived peptides at different stages during the course of IHNV infection. The results indicate that the 3‐h fraction of casein and α_S2‐casein hydrolysates reduced the yield of infectious IHNV in a dose‐dependent manner and impaired the production of IHNV‐specific antigens. Hydrolysates of total casein and α_S2‐casein target the initial and later stages of viral infection, as demonstrated by the reduction in the infective titre observed throughout multiple stages and cycles. In vivo, more than 50% protection was observed in the casein‐treated fish, and the kidney sections exhibited none of the histopathological characteristics of IHNV infection. The active fractions from casein were identified, as well as one of the individual IHNV‐inhibiting peptides. Further studies will be required to determine which other peptides possess this activity. These findings provide a basis for future investigations on the efficacy of these compounds in treating other viral diseases in farmed fish and to elucidate the underlying molecular mechanisms of action. However, the present results provide convincing evidence in support of a role for several milk casein fractions as suitable candidates to prevent and treat some fish viral infections.     

Spectrofluorometric determination and thin layer chromatographic identification of tyramine in wine.

A method is described for determining tyramine in wine by sand column extraction in an alkaline medium with anhydrous sodium sulfate. Tyramine is identified and quantitated by spectrofluorometry after the final extract is reacted with alpha-nitroso-beta-naphthol; identity is confirmed by thin layer chromatography. The average recovery was 98.93%. The method is applied to samples of 3 different wines obtained throughout the vinification process. Tyramine, which was not present in the must, appears in considerable quantities 15 days after the vinification process has begun.     

Observations on the design and use of footbaths for the control of infectious hoof disease in dairy cattle

A survey of 65 freestall-housed dairy herds in five different countries, with an average of 1023 milking cows, found that footbaths were used 1-4 times per day for 1-7days per week, with between 80 and 3000 cows passing through the bath between chemical changes. The most common agents used were copper sulfate (41/65) and formalin (22/65). Twenty-seven herds (42%) used more than one chemical. The median footbath measured 2.03m long by 0.81m wide, and was filled to a depth of 0.11m with a volume of 189L (range 80-1417L). An observational behavioral study was conducted using a custom-designed footbath to test four different bath dimensions, with two different step-in heights. The number of immersions per rear foot was counted for each footbath design for each cow passing through the bath on two consecutive days. While a higher step-in height significantly increased the number of foot immersions, the effect was small compared to the effect of length. The probability of each rear foot receiving at least two immersions reached 95% at a bath length of 3.0m, and a significant increase in the frequency of three and four immersions per foot was observed between 3.0 and 3.7m. In order to optimize the number of foot immersions per cow pass, while limiting the footbath volume, this study recommends a bath 3.0-3.7m long, 0.5-0.6m wide, with a 28cm step-in height.     

The relationship between residual feed intake and feed intake behavior in group-housed Duroc barrows

Because feed is the major input in pork production, conversion of feed into lean tissue at minimum costs has been a focus for improvement. Several researchers have proposed using residual feed intake (RFI) rather than feed conversion ratio (FCR) for genetic improvement of feed efficiency. Little is known about the variation in RFI in pigs. As several studies suggest a greater RFI is related to greater animal activity levels, the current study investigated the phenotypic relationship between RFI and feed intake (FI) behavior of 104 group-housed growing Duroc barrows allowed ad libitum access to feed. Feed intake, BW gain, feeding time (TIME), feeding frequency (VISITS), RFI, and FCR were calculated for 5 periods of 14, 23, 28, 21, or 23 d in length (periods 1 through 5, respectively) on animals that were between 73 to 95 d of age at the start of the testing period. Barrows that grew faster consumed more feed (P < 0.001), and barrows that consumed more feed were fatter (P < 0.01). There were no correlations between VISITS and TIME, between VISITS and FI, or between VISITS and RFI. Barrows that spent more time at the feeder, however, consumed more feed (P < 0.05) and had greater RFI in periods 1, 3, and 5 (P < 0.05). As expected, FI and FCR were highly correlated with RFI (P < 0.001). These results suggest that a greater FI rather than greater feed intake activity resulted in greater RFI values.     

Recombinant bovine interleukin-12 stimulates a gut immune response but does not provide resistance to Cryptosporidium parvum infection in neonatal calves

This study was undertaken to determine if administration of recombinant bovine interleukin-12 (rBoIL-12) could stimulate a cellular immune response that protected calves from an oral challenge inoculation with Cryptosporidium parvum oocysts. In a first experiment, rBoIL-12 intraperitoneally administered as a single dose 1 day before challenge inoculation, did not alter the course of infection. The percentage of immune competent cells and levels of cytokine gene expression in the ileo-cecal mucosa and in the draining lymph nodes of treated calves were similar to those of untreated control calves. However, when rBoIL-12 was subcutaneously administered daily from 2 days before infection to 2 days after infection, a consistent increase of T lymphocytes and an higher expression of interferon-gamma (IFN-gamma) was detected. Again, treatment did not alter the course of infection. Similar results were obtained when rBoIL-12 was administered daily for 4 days beginning 2 days after oral inoculation. These data indicate that although rBoIL-12 stimulated a strong immune response in the gut of neonatal calves, the response was not able to provide protection from challenge inoculation with C. parvum oocysts.     

Standing surgical removal of inspissated guttural pouch exudate (chondroids) in ten horses

OBJECTIVE: To report use of a modified Whitehouse approach in standing horses for management of inspissated guttural pouch empyema. STUDY DESIGN: Retrospective study. ANIMALS: Adult horses (n=10) with guttural pouch empyema. METHODS: Inspissated exudate in 1 or both guttural pouches was removed surgically through a modified Whitehouse approach, with the horses standing and sedated. Medical records of affected horses were reviewed to determine history; physical, endoscopic, and radiological examination findings; surgical technique; complications, and outcome. RESULTS: All horses had purulent nasal discharge; 3 horses had dysphagia, 2 had recurrent laryngeal neuropathy on the side affected by guttural pouch empyema, and 1 had persistent soft palate displacement. Inspissated exudate was removed safely without causing apparent discomfort. Eight horses returned to their previous level of athletic activity after surgery; 1 horse dysphagic before surgery, was euthanatized because of persistent dysphagia after surgery, and 1 horse died 1 week after surgery for unknown reasons. Streptococcus equi subsp equi was isolated from the affected guttural pouch of 3 horses. CONCLUSIONS: Inspissated exudate can be removed surgically from the guttural pouch in standing horses through a modified Whitehouse approach. CLINICAL RELEVANCE: To eliminate risks associated with general anesthesia and avoid surgical suite contamination, removal of chondroids can be performed in standing sedated horses through a modified Whitehouse approach.