Zika virus persists in the central nervous system and lymph nodes of rhesus monkeys.

The Zika virus persists in the central nervous system and lymph nodes of rhesus monkeys as the virus was seen in tissue weeks after it cleared from blood. A study published online in Cell,reveals that Zika virus can persist in cerebrospinal fluid (CSF), lymph nodes and colorectal tissue of infected rhesus monkeys for weeks after the virus has been cleared from blood, urine and mucosal secretions. The researchers infected 20 rhesus monkeys with Zika virus and noted that although virus was cleared from peripheral blood within 7-10 days, it was detected in CSF for up to 42 days and in lymph nodes and colorectal tissue for up to 72 days. Immunologic data showed that the emergence of Zika virus-specific neutralizing antibodies correlated with the rapid control of the virus in plasma. However, Zika-specific antibodies were not detected in CSF, which could be why the virus remained there longer. These findings suggest that persistent virus in the central nervous system may contribute to the neurological issues associated with Zika virus infection in people.

Management of infectious bursal disease virus( IBDV) in broilers.

The management of infectious bursal disease virus( IBDV) in broilers for most farmer is to ensure a strict and vaccination regime for their breeders. The maternal immunity passed on to chicks will usually help protect them until they are 3 to 4 weeks of age. This projection of conferred immunity sometimes does not work out like planned due to certain factors; 1) Efficacy of some vaccines. 2) Vaccine failure or break. 3) Early infection of flock before 2 weeks of age leading to permanent immune suppression despite maternal immunity. When IBDV infection in broiler flocks occurs after 3 to 4 weeks of age , when maternal immunity has waned it can result in reduced feed efficiency, slowed growth rate and uneven size of flocks. This will also lead to temporary immune suppression with a higher risk of secondary infections, which often become more critical in antibiotic-free production. The prevention of the damaging effects of IBDV by farmers can be initiated by simulating active immunity in their flocks. Live, attenuated vaccines used in layers with high success rate can also help prevent IBDv in broilers. Farmers have turned to in-ovo vaccination at hatchery at day 1 to forestall any disease occurrence. The common vaccines are the recombinant herpesvirus of turkey HVT- IBDV and immune-complex (IC) vaccines. . The efficacy of HVT-IBDV vaccines has been demonstrated as these vaccines have been shown to induce protection against multiple IBDV strains with no risk of bursa damage. The key to effective use of HVT-IBDV is that it should be the only recombinant vaccine used in the flock to prevent interference. Combining recombinant HVT-IBDV vaccines with other recombinant HVT vaccines e.g for Newcastle disease or infectious laryngotracheitis is not recommended because viral interference can occur between the HVT viruses. In cases where an HVT recombinant vaccine is needed to manage either of the respiratory diseases, an alternative to the HVT-IBDV vaccine is recommended. The immune-complex vaccines (IC) contain a mixture of modified-live vaccine virus and anti-IBDV antibody. The antibodies in these products bind to the IBDV vaccine virus. These antibodies greatly reduces the ability of the vaccine virus to replicate early in the broiler’s life ,thus damage to the bursa and immune suppression are minimal and often undetected. This ability to act early in the of the broiler makes the IC-IBDV vaccines a safe alternatives to HVT-IBDV vaccines. Vaccinating with an IC-IBDV vaccine in the presence of maternal antibodies to IBDV seems counter intuitive or counter-productive but these vaccines have been shown to stimulate active immunity to IBDV, even when maternal antibody titers are relatively high.

The challenge of feeding diseased livestock.

The challenge of feeding diseased livestock is worthy of note because nutrient requirements for fighting disease are quite different from those required for productive purposes. The efforts exercised by researchers, nutritionists and veterinarians,to have a clear understanding of how to feed animals under disease stress is paying off in terms of different intervention techniques. Presently the aim is to prevent disease mostly through nutrition and by a mild veterinary intervention scheme that focuses on hygiene and soft medicinal solutions. Sick animals are treated with invasive medical methods and the nutrition of such animals remains unchanged as the same feed is offered to healthy or sick animals,this is where the problem lies. There is a need to establish clear nutritional guidelines for treating animals that are stressed because of disease both clinically and even sub clinically. Sick / diseased animals exhibit anorexia, or they simply don’t eat much or even at all, which is usually the most common sign if not the key pointer that something is wrong. The question now is what is anorexia and what is its role in disease management? Anorexia is a response exhibited by a diseased animals as they attempt to reduce the metabolic burden from feed and switches focus from productivity such as growth, eggs, milk, pregnancy and maintenance but towards fighting the disease. Anorexia is a method with which the animal tends to stem tide of infection or limit the activity of pathogens by boosting the immune system. The challenge of feeding diseased livestock is significant to animal health because of the role of anorexia in diseased animals or stressed animals. When an animal is off-feed or anorectic,reduction of nutrient ingestion limits the extent of pathogen proliferation especially in the case of gut bacteria. The pathogens in the gastrointestinal tract that hitherto had unlimited access to nutrients from feed, are starved limiting the rate of proliferation and if the digestive system is impaired as is often the case with gastrointestinal disorders,this is a double plus for the benefit of anorexia. The feed intake reserves more energy for immune system functions,and such energy is derived from body fat reserves.The prolonged dependence on these stores emaciates animals,though at the onset, it is actually beneficial for the animal to draw on reserves. When the animal is off feed glucagon production is enhanced and the immune system response is thus enhanced in turn creating an environment to rid body of pathogen. The challenge of feeding diseased livestock is that although anorexia is beneficial at onset of disease,prolonged anorexia results in profound emaciation from which recovery may be prolonged.Another challenge of feeding diseased livestock is that diseased animals require more nutrients than healthy animals,the twist is that force-feeding sick animals results in increased mortality and reduced survival time. The challenge of feeding diseased livestock now is that since the role of anorexia to curtail the infection is understood,and the danger of prolonged anorexia is also known then the time of intervention and type of intervention is the key to successful treatment.

Cassava as a global livestock feed ingredient.

Cassava known mostly for its starch-rich tubers is a plant that also offers many possibilities to provide other lesser-known feed ingredients for man and livestock. Cassava is a plant that is very tolerant to poor growing conditions as it can be cultivated in regions suffering from poor soil, droughts and even frequent plant diseases. 

Under such conditions, it yields about 13 metric tons of tubers per hectare. Of course, when grown in near-ideal (tropical) conditions, yield can reach up to 80 metric tons of tubers per hectare. Cassava is the second largest carbohydrate-rich crop worldwide, with over 9 million hectares of cultivated land devoted to cassava production in Africa and Asia. 

Global cassava cultivation expands to Asia, Latin America and Africa due to high demands from the human, feed, industrial starch and ethanol industries. Thailand is the largest exporting country for cassava products but surpassed by Nigeria and Brazil, two countries that use their local cassava internally. Nigeria has used cassava extensively as food for man,making different products such as garri,tapioca, cassava chips,starch and flour. 

Cassava has also made an entrance to livestock feed to boost productivity and reduce cost of production by using local feed. Cassava peels and cassava root meal have been explored in livestock with good results,see The cyanide content of the plant is the major reason why many farmers are skeptical about using it but processing reduces the cyanide content and also cyanide content varies with cassava specie making the inclusion in livestock feed safe .

There are two types of cyanogenic glucosides in cassava: linamarin and lotaustralin, the first making up to 93 percent of total. When animals eat the raw cassava tubers or leaves ,they consume the cyanogenic compounds thus releasing the cyanide which is highly toxic to animals causing asphyxia and death. Processing the cassava removes the cyanide thus emphasis is on proper processing, when the cassava peels are sun dried or oven dried, linamarase enzyme is released and this comes into contact with the cyanogenic glucosides and releases hydrogen cyanide (HCN), which is volatile and evaporates, and because sun drying takes longer time span than oven it releases more of cyanide which makes the peels safe. 

 The processing removes as much as 90% by this processing method.The raw cassava pulp contains as much as 200 mg/kg HCN, whereas these levels are reduced to 31 and 27 mg/kg, by oven-and sun-drying, respectively. The whole tuber contains as much 400 mg/kg HCN, with the peel containing as much as 800 mg/kg. 

The leaves are even richer in this compound, containing up to 1,500 mg/kg. There are several varieties of cassava, ranging from 75 to 1,000 mg/kg HCN, and factors such as soil conditions, fertilizer and weather also affect the concentration of HCN, so choosing the variety with the minimum cyanide content will be a factor to jump start the processing for safety. 

 Cassava leaves can also used as feed ingredient but must be dried and milled to create cassava leaf meal, a material rich in protein and fiber but low in energy. The inclusion in feed must be with extra caution because of the very high levels of HCN in raw leaves. 

 The high level of cyanide in leaves can be reduced by proper processing, timing of the harvest and appropriate variety selection. 10 metric tons dried cassava leaf meal can be produced per hectare, this is a significant by-product, suited especially as an animal feed.

Alternative vegetable protein sources for broilers.

Alternative vegetable protein sources for broilers. Soybean meal and dried distiller’s grains with solubles (DDGS) remain the primary source of protein for broilers. Soybean meal is the No. 1 source of protein for broilers worldwide, but its use is supplemented by locally available secondary sources such as DDGS ,rapeseed meal and sunflower meal . There are minor, local sources of protein that can offer the benefits of volume and low prices. When such opportunity arises, broiler producers are enticed to use these alternative, protein-rich ingredients, but results are often disappointing. The main reason is not as much quality, but rather lack of understanding of the limitations posed by each ingredient. These limitations arise from the concentration, which can be quite variable, of certain anti-nutritional factors that cause an almost toxic effect in the bird’s metabolism. Knowing these factors and their concentration can lead to very successful feed formulations using alternative protein sources and to very profitable production outcome. 1) Palm kernel meal The rapid growth of palm oil production in Asia, Australia, South America and Africa has led to tremendous quantities of palm kernel meal being available for all types of livestock. Not a protein-rich ingredient (less than 18 percent crude protein), palm kernel meal remains an interesting ingredient because it can contribute to significant cost savings. It is poor in lysine and methionine, with average digestibility values, but it contains sufficient energy to constitute a good part of the total dietary protein fraction. It is also relatively high in crude fiber (up to 20 percent). In many aspects, palm kernel meal can be compared to corn gluten feed. It is speculated that any adverse effects of palm kernel meal observed in broilers is due to its grittiness and overall physical quality aspects and not due to its nutrient profile. As such, high quality palm kernel meal can be used relatively freely, within constrains imposed by its limited nutrient profile, in broiler diets. 2) Cottonseed meal A by-product of the extraction of oil from cotton seeds, this protein source is not often available for broiler feed due to competition from ruminant feeds — something that increases its price. Cottonseed meal contains about 40 percent crude protein, of moderate digestibility, whereas the major anti-nutritional factor is gossypol. Broilers can withstand much higher levels of gossypol compared with layers, but the usually high fiber concentration (15 percent) in cottonseed meal will pose an upper limit in formulation. In regards to gossypol, it is possible to reduce the negative effects by neutralizing it through the addition of certain iron salts. Low- or no-gossypol cultivars are also available yielding meals that are tolerated well by broilers. A gradual introduction into feed formulas is recommended. 3) Corn gluten meal There is nothing really wrong with corn gluten meal, which is a by-product of the starch extraction process from corn kernels. It contains about 60 pecent crude protein, with digestibility values being comparable to that of corn. It also contains the majority of pigments from the kernel, and it leads to heavy pigmentation of the broiler skin — which can be a desirable or undesirable carcass trait according to market circumstances. continue

Researchers find Zika RNA in Brazilian A. albopictus mosquitoes.

Researchers find Zika RNA in Brazilian A. albopictus mosquitoes.Researchers detected fragments of Zika virus RNA — but not live virus — in Aedes albopictus mosquitoes collected in a Brazilian state hit hard by the recent Zika outbreak. A different mosquito, A. aegypti, has been the primary vector for Zika and the main driver of the recent outbreak in the Americas. In the United States, the range of A. albopictus is far greater than that of A. aegypti. This results mean that Aedes albopictus may have a role in Zika virus transmission and should be of concern to public health, this mosquito is found worldwide with a wide range of hosts and has adapted to colder climates. The role of this mosquito in Zika virus transmission needs to be assessed. more

Malaria hospitalizations in US more common.

Malaria hospitalizations in US more common than realized. A new study has shown that Malaria hospitalizations in the United States are more common than previously thought, possibly due to increased travel to regions where the disease is endemic. The study published in in the American Journal of Tropical Medicine and Hygiene, suggests that as more infected travelers return to the U.S., clinicians must develop strategies to combat the potentially fatal disease. It appears more and more Americans are traveling to areas where malaria is common and many of them are not taking preventive measures, such as using anti-malarial preventive medications and mosquito repellents, even though they are very effective at preventing infections. The researchers searched hospital records in the Nationwide Inpatient Sample database for malaria-related hospitalizations from 2000 to 2014. They estimated that there were 22,029 malaria hospitalizations in the U.S., with an average of 1,469 cases per year, during that period. Men accounted for about 60% of patients with malaria. Blacks made up 52.5% of patients, whites 24%, Hispanics 6.3%, Asians and Pacific Islanders 5.9% and Native Americans 0.9%. The disease-causing species was known in 52.9% of cases. Plasmodium falciparum — which is known to cause a strong majority of severe and fatal cases — accounted for 72.9% of those. An estimated 4,823 (22%) cases were deemed severe malaria. The most common complication was renal failure (9.6%), followed by severe anemia (7.2%), cerebral malaria (4.3%), acute respiratory distress syndrome (4.1%) and jaundice (3.7%). One hundred eighty-two (0.8%) patients died in the hospital. more