Freedom from Tritrichomonas foetus infection in cattle in St. Kitts

Tropical Animal Health and Production - Trichomonosis is an endemic disease in cattle that are reared under extensive conditions and bred by natural mating. It causes profound economic...     

Survival of viruses in fermented edible waste material

The survival of selected viruses in fermented edible waste material was studied to determine the feasibility of using this material as a livestock feed ingredient. Seven viruses, including pseudorabies, Newcastle disease, infectious canine hepatitis, avian infectious bronchitis, measles, vesicular stomatitis, and a porcine picornavirus were inoculated into a mixture of ground food waste (collected from a school lung program) containing Lactobacillus acidophilus. Mixtures were incubated at 5 C, 10 C, 20 C, and 30 C for 96 hours. Temperature, pH, and redox potential were monitored. Samples for virus isolation were obtained daily. Newcastle disease virus and infectious canine hepatitis virus survived the entire test period. The porcine picornavirus was inactivated at 30 C after 74 hours, but survived for the entire test period at the other temperatures. Pseudorabies virus was inactivated at 20 C and 30 C within 24 hours, but survived for 48 hours at 10 C and 96 hours at 5 C. Avian infectious bronchitis virus was inactivated at 20 C and 30 C within 24 hours, but survived 72 hours at 5 C and 10 C. Measles and vesicular stomatitis viruses were rapidly inactivated at all 4 temperatures.     

Ovoviviparously produced Artemia nauplii are a suitable live food source for the larvae of the African catfish (Clarias gariepinus: Burchell, 1822)

Brine shrimp Artemia, the most common live food organism used in larviculture, can reproduce either oviparously (production of dormant cysts) or ovoviviparously (direct production of nauplii), depending on environmental conditions. Ovoviviparous Artemia nauplii have seldom been considered as a source of live food in aquaculture, partly due to the convenience and the developed techniques associated with the production and use of the dormant cysts. In many countries in Africa, however, hatchery managers do not have access to a reliable supply of affordable good quality cysts. In this study, we therefore demonstrated the potential of a system designed for the continuous ovoviviparous production of nauplii at low salinity, using Great Salt Lake Artemia franciscana and micronized agricultural material as feed. The suitability of the produced nauplii was tested by feeding them directly to Clarias gariepinus larvae in comparison with oviparous nauplii and decapsulated cysts. Higher survival (100%), better protein efficiency ratio (2.6 ± 0.1) and food conversion ratio (1.0 ± 0.1) was observed in larvae fed with the ovoviviparous nauplii (p < 0.05). Overall, we conclude that the ovoviviparous nauplii could serve as an alternative live food for larval fish. If optimized, the system could be validated for integration in hatcheries.     

Anthropogenic factors and the risk of highly pathogenic avian influenza H5N1: prospects from a spatial-based model

Beginning in 2003, highly pathogenic avian influenza (HPAI) H5N1 virus spread across Southeast Asia, causing unprecedented epidemics. Thailand was massively infected in 2004 and 2005 and continues today to experience sporadic outbreaks. While research findings suggest that the spread of HPAI H5N1 is influenced primarily by trade patterns, identifying the anthropogenic risk factors involved remains a challenge. In this study, we investigated which anthropogenic factors played a role in the risk of HPAI in Thailand using outbreak data from the “second wave” of the epidemic (3 July 2004 to 5 May 2005) in the country. We first performed a spatial analysis of the relative risk of HPAI H5N1 at the subdistrict level based on a hierarchical Bayesian model. We observed a strong spatial heterogeneity of the relative risk. We then tested a set of potential risk factors in a multivariable linear model. The results confirmed the role of free-grazing ducks and rice-cropping intensity but showed a weak association with fighting cock density. The results also revealed a set of anthropogenic factors significantly linked with the risk of HPAI. High risk was associated strongly with densely populated areas, short distances to a highway junction, and short distances to large cities. These findings highlight a new explanatory pattern for the risk of HPAI and indicate that, in addition to agro-environmental factors, anthropogenic factors play an important role in the spread of H5N1. To limit the spread of future outbreaks, efforts to control the movement of poultry products must be sustained.     

Developmental Competence and Embryo Quality of Small Oocytes from Pre‐pubertal Goats Cultured in IVM Medium Supplemented with Low Level of Hormones,Insulin–Transferrin–Selenium and Ascorbic Acid

The aim of this study was to test the effect of insulin–transferrin–selenium (ITS) and L‐ascorbic acid (AA) supplementation and the hormonal level during in vitro maturation (IVM) of small oocytes from pre‐pubertal goat on the blastocyst yield and quality. Concretely, we used four maturation media: conventional IVM medium (CM), growth medium (GM: CM+ITS+AA and low level of hormones), modified CM (mCM: CM with low level of hormones) and modified GM (mGM: CM+ITS+AA and normal level of hormones). Cumulus–oocyte complexes (COCs) were classified into two categories according to oocyte diameter: <125 μm and ≥125 μm. Large oocytes were matured 24 h in CM (Treatment A). Small oocytes were matured randomly in six experimental groups: Treatment B: 24 h in CM; Treatment C: 12 h in GM and 12 h in CM; Treatment D: 24 h in mGM; Treatment E: 12 h in mGM and 12 h in CM; Treatment F: 12 h in mCM and 12 h in CM; and Treatment G: 12 h in GM and 12 h in mGM. After IVM, oocytes were fertilized and cultured for 8 days. The blastocyst quality was assessed by the survival following vitrification/warming and the mean cell number. When different maturation media were combined, the blastocyst rate did not improve. The large oocytes produced the highest blastocysts yield. However, the culture of small oocytes in GM (53.3%) enhanced the post‐warming survival of blastocysts compared to large oocytes matured in CM (35.7%). In conclusion, IVM of pre‐pubertal goat small oocytes in GM would be useful to improve the quality of in vitro‐produced blastocysts.     

Mass culture of fairy shrimp Branchinecta orientalis (G. O. Sars 1901) (Crustacea: Anostraca) using effluent of rainbow trout Oncorhynchus mykiss (Walbaum 1792) ponds

The variable quality and high price of Artemia (Leach 1819) cyst products, used worldwide as live food, motivate aquaculturists to find an appropriate alternative, especially for fresh/brackish water organisms. In this study, Branchinecta orientalis (G. O. Sars 1901), a common fairy shrimp in north‐western Iran, was reared for 15 days using effluent from trout ponds enriched with effluent filtrate as sole feed, or co‐fed with microalgae (Scenedesmus sp.). The effluent filtrate was replaced by algae at different ratios (25% and 50%), and feeding experiments were designed at densities of 100, 200 and 400 individuals/L in 3‐L containers and at 100 individuals/L in 20‐L containers. The results indicated that, at a certain density, the final length and survival were not significantly affected by different feeding regimes (p > .05). In 3‐L containers, the highest length and survival were observed at the lowest density. B. orientalis contained the highest amounts of proteins, carbohydrates and lipids, though, when co‐fed algae, although the differences with the treatment fed solely effluent filtrate were often limited. Inclusion of algae in the diet also resulted in higher levels of a number of PUFAs. Our study proves that B. orientalis can be mass‐cultured successfully using trout effluent as culture medium without additional microalgae. Fish pond effluent is massively available as a cheap food source. Recycling aquaculture effluent for this type of live food production contributes to lowering the use of natural resources and to less discharge of nutrient loads into natural water bodies.     

Hatchery‐reared endangered Colorado pikeminnow (Ptychocheilus lucius) undergo a gradual transition to piscivory after introduction to the wild

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Effect of Ischemia and Reperfusion on Neutrophil Accumulation in Equine Microvascular Tissue Flaps

Objective— To investigate neutrophil accumulation after ischemia and reperfusion (IR) in microvascular tissue flaps in horses.
Study Design— Randomized controlled experiment.
Sample Population— A total of 8 horses between 1 and 10 years of age, 4 of each sex.
Methods— Control and experimental myocutaneous island flaps based on the superficial branch of the deep circumflex iliac vessels were dissected on each horse. Atraumatic vascular clamps were applied to the pedicle of the experimental flap for 90 minutes and then removed to allow reperfusion. Based on the assumption that rapid infiltration of neutrophils into affected tissues is a hallmark of IR injury, radiolabeled autogenous leukocytes were used to indirectly quantify neutrophil accumulation in flap tissues. Labeled leukocytes were administered through a jugular catheter 30 minutes before flap reperfusion. Biopsies were collected from each flap over a 6 hour postischemia time period; in group 1 (  n = 4  ) from 0 to 6 hours postischemia, and in group 2 (  n = 4  ) from 24 to 30 hours postischemia. Biopsies were examined scintigraphically and histologically for evidence of neutrophil infiltration.
Results— All control flaps survived and 6 of 8 experimental flaps survived. There was no significant evidence of acute neutrophil infiltration into flap tissues after reperfusion in either group.
Conclusions— The results of this study suggest that equine myocutaneous flap tissues can survive a 90-minute ischemic period and reperfusion. No significant evidence of the occurrence of IR injury in flap tissues was found.
Clinical Relevance— The reasons for the previously reported failures of equine free tissue transfer remain uncertain, but they do not appear to be caused by neutrophil mediated injury associated with ischemia and reperfusion.