Poultry litter intake by cattle: epidemiological characterization and sanitation of health hazards

Article history The aim of the current study is to report a sanitary episode of poultry litter intake by cattle, based on the epidemiological characterization of health hazards and of sanitation measures implemented in the investigated property. The sanitary episode resulted from an anonymous report about the use of poultry litter as cattle food. The rural property located in São José de Ribamar County, Maranhão State, was inspected 72 hours after the complaint. Based on the initial inspection, 119 Nellore cattle were subjected to confinement system and fed on cattle food added with poultry litter. Given such discovery, cattle food samples were collected and sent to the National Agricultural Laboratory of Santa Catarina State. Laboratory results have shown the incidence of uncalcined bones, unhydrolyzed feathers and blood in the analyzed samples, which confirmed the inclusion of animal byproducts in cattle’s diet. The current study is the first official report about poultry litter intake by cattle in Maranhão State, which was officially confirmed by laboratory results evidencing the presence of animal by-products in the analyzed samples. It is essential intensifying the active inspections carried out in ruminant-breeding farms in Maranhão State, as well as controlling poultry litter transit by documenting the purpose of its use. Received 19 February 2019 Accepted 01 May 2019


INTRODUCTION
The production, distribution and use of pig/poultry waste, such as poultry litter, to feed ruminants is forbiden in Brazil. Normative Instruction (NI) n. 08, which is the legal apparatus regulating this prohibition, was issued by the Ministry of Agriculture, Livestock and Supply (MAPA -Ministério da Agricultura, Pecuária e Abastecimento) on March 25, 2004(BRASIL, 2004. The use of poultry litter is routine in Brazil, although its use to feed ruminants was banned in the country and despite understanding about health hazards (Bovine Spongiform Encephalopathy (BSE), botulism and the incidence of antimicrobial agents) resulting from this practice and the sanctions expected to result from its use (DIEHL, 2010). According to Leme;Boin (2000), using this by-product as protein in the diet of ruminants (cattle, buffaloes, goats and sheep), mainly of cattle, is not a recent procedure. It basically results from two aspects, namely: ruminant's ability to use food containing non-protein nitrogen (NPN) compounds and to metabolize fibrous food; and the abundance, and reduced value, of this material.
According to Galiza et al. (2010), less than one gram of infecting material can transmit BSE (bovine neurodegenerative disease); therefore, even low meatand-bone meal concentrations in ruminant's diet can transmit the disease.
Official sanitary measures were implemented after the global BSE crisis in order to control the disease, mainly because it is transmissible to humans through infected tissue intake (SEUBERLICH; HEIM; ZURBRIGGEN, 2010). The entire production chain has been inspected since 1996 in order to avoid BSE introduction in Brazil (DIEHL, 2010).
According to Seuberlich;Heim;Zurbriggen (2010), the number of new BSE cases has decreased after ruminants' diet supplemented with meat-and-bone meal, as well as the use of specified risk materials (SRMs), were banned. Based on Diehl (2010), animal feed industries, rendering plants and ruminant-breeding sites should be regularly inspected in order to avoid poultry litter use as animal food. These measures and actions can be simultaneously applied throughout the Brazilian territory.
Therefore, the aim of the current study was to report a sanitary episode of poultry litter intake by cattle, based on the epidemiological characterization of health hazards and of sanitation measures implemented in the investigated property.

CASUISTRY -CASE REPORT
On September 16, 2016, an agricultural inspector who worked for Maranhão State Agency of Agricultural and Livestock Defense (AGED/MA -Agência Estadual de Defesa Agropecuária do Estado do Maranhão) received an anonymous phone call reporting about a rural producer who was supplementing cattle's diet with poultry litter. Seventy-two (72) hours later, the Official Veterinary Service (SVO -Serviço Veterinario Oficial) of Maranhão State sent its professionals to the rural property in question to investigate whether the complaint was real.
The rural property in São José de Ribamar County, Maranhão State, had 119 Nelore mongrel male bovines in the age group 24-36 months who were kept in semiintensive production system. The animals were rented by the farmer to be used in the sport practice known as vaquejada. The property did not breed any other species.
At the time, cattle food samples were collected in duplicate (inspection and confirmation test) in the presence of the farm owner ( Figure 1a). Next, they were sent to the National Agricultural and Livestock Laboratory of Santa Catarina State (LANAGRO/SC -Laboratorio Nacional Agropecuário de Santa Catarina) to enable the identification, or not, of animal by-products in them, based on microscopy technique, according to NI n. 69 from September 23, 2003(BRASIL, 2003. The farm owner was instructed about the health strategies to be adopted until the laboratory results were released and cattle transit was banned from the site. Simultaneously, 119 bovine individuals who had access to cattle food suspected of having prohibited animal byproducts were identified with cold paste and acrylic water-based paint ( Figure 1b). Complementary visits to the rural property were scheduled in order to follow up ruminants who had access to suspicious food (transit; robbery, theft or escape; and disease or death cases); they took place until the laboratory results were released.

DISCUSSION
The initial inspection in the reported rural property showed that poultry litter was added to the diet of the investigated cattle (Figure 2). Laboratory results have shown uncalcined bones, unhydrolyzed feathers and blood in the analyzed samples, and this outcome evidences cattle feeding on animal by-products.  Health hazard was terminated after slaughter. However, since it involved the use of animal by-products in cattle food, the farmer was fined in R$ 1,500.00; he also had to pay for the inter-municipal transportation and for the slaughter of the 119 infected animals. Meat deriving from the slaughtered animals was released for consumption, because BSE (in case of infection) can only be transmitted through genetic material and SRMs. There is significant incidence of residual risk materials when SRMs are not properly removed. Therefore, SRMs should not be used to feed ruminants, or to produce meat and bone meal or fatty products used in rendering processes, in order to avoid BSE agent transmission (BRASIL, 2008).
According to Fonseca (2015), keeping the ban on cattle diets supplemented with animal by-products, as well as SRM removal, are the main risk mitigation measures that should be kept even after the eradication of classic BSE cases. However, when it comes to SRMs, it is essential adopting a strong scientific basis at the time to decide whether these measures are appropriate to reduce tissue infectivity in bovine carcasses infected with atypical BSE prion.
According to Fonseca (2015), there have been noticeable improvements in risk mitigation measures focused on classic BSE cases. However, it is necessary implementing a continuous surveillance system if one takes into consideration the assumption that atypical strains can be sporadic and do not present geographical trends.
BSE identification in a given territory brings severe commercial implications to the image of the affected countries in the international market. Importing countries can have a negative reaction to it and fully or partially close their borders to such infected goods. Consequently, the exporting country can suffer a significant impact from BSE idenfication, even when the health issue is proven to be under control. In addition, BSE burdens both public and private budgets due to the investments required to control and eradicate the disease.
Accoring to Diehl (2010), based on SVO's inspections conducted in Brazil in 2010, 405 cattle from seven properties in Paraná State were slaughtered for been fed with poultry litter. More than 1,500 cattle from a single property in Mato Grosso do Sul State were slaughtered for being fed with cattle food containing animal protein.
Brazil is in the BSE-controlled risk category. The country will have to prove, among other premises, the actual ban on ruminant diets supplemented with animal byproducts -i.e., the feed ban -in order to be classified in the 'insignificant BSE-risk category' (the lowest risk category) in future evaluations (DIEHL, 2010).
According to AGED -MA, nowadays, there are 17,392,607 poultry registered in 48,179 livestock farms (MARANHÃO, 2018). According to Maranhão Association of Poultry Farmers (AVIMA, 2012), the state's geographic location favors a good poultry-farming performance. In addition, the state has excellent poultry production conditions, not only because of its favorable climate, but also because it produces most of the grain supply (corn and soybeans) in the Northeastern Region.
Moreira (2018) conducted a study from 2013 to 2016 to characterize the transit of non-edible animal by-products in Maranhão State and recorded the production of 28,615.39 tons of poultry litter. The aforementioned aspects justify the adoption of tighter surveillance on ruminant-breeding farms, as well as the control of poultry litter production, use and trading.

CONCLUSION
The current study was the first official report on poultry litter intake by cattle in Maranhão State, which was officially confirmed by laboratory results incidencing the presence of uncalcined bones, unhydrolyzed feathers and blood in the analyzed samples. This report drew attention to the practice of feeding cattle with poultry litter, despite a series of prohibitive measures addressed in Brazilian regulations and implemented in the country. Emphasis was given to the need of conducting active inspections on ruminant-breeding farms, as well as of controlling poultry litter transit by documenting the purpose of its use.