Consumo e digestibilidade de feno de baixa qualidade suplementado com nitrogênio não protéico em bovinos Intake and digestibility of low-quality hay with nonprotein nitrogen supplementation in cattle

O objetivo deste trabalho foi avaliar o efeito de níveis de inclusão de nitrogênio não protéico, em suplementos fornecidos a tourinhos Hereford, com 17 meses e peso médio de 220 kg, alimentados com feno de tifton (Cynodon dactylon) ad libitum. Os tratamentos avaliados foram: feno + suplemento sem uréia; feno + suplemento com 0,28 g de uréia kg-1 PV0,75; feno + suplemento com 0,55 g de uréia kg-1 PV0,75; feno + suplemento com 0,83 g de uréia kg-1 PV0,75 e feno + suplemento com 1,11 g de uréia kg-1 PV0,75. O feno apresentou, na média, 3,86% de proteína bruta e 84,66% de fibra em detergente neutro. Não se constatou efeito da suplementação sobre a digestibilidade da matéria orgânica, matéria orgânica do feno, fibra em detergente neutro, celulose e hemicelulose; o consumo total desses itens respondeu quadraticamente à suplementação com níveis crescentes de nitrogênio não protéico. A suplementação não afetou a excreção fecal metabólica de matéria orgânica, o que sugere aumento na taxa de passagem (variação no consumo) e na taxa de digestão (digestibilidade constante). O consumo de matéria orgânica digestível apresentou comportamento quadrático com aumento dos níveis de uréia na dieta. Quando o nível de proteína degradável no rúmen foi equivalente a 8,1% da matéria orgânica digestível, a relação de consumo entre esses componentes foi otimizada.<br>The objective of this work was to evaluate the effect of nonprotein nitrogen supplementation levels on the digestibility of low-quality hay (Cynodon dactylon), which was offered ad libitum to Hereford bulls aging 17 months and weighing 220 kg. The evaluated treatments were: hay + no urea supplement; hay + supplement with 0.28 g urea kg- 1 BW0.75; hay + supplement with 0.55 g urea kg-1 BW0.75; hay + supplement with 0.83 g urea kg- 1 BW0.75 and hay + supplement with 1.11 g urea kg- 1 BW0.75. Hay composition presented 3.86% of crude protein and 84.66% of neutral detergent fiber. Digestibility of organic matter, organic matter of forage, neutral detergent fiber, cellulose and hemicellulose were not affected by nonprotein nitrogen level; total intake of these components showed a quadratic response to nonprotein nitrogen supplementation. Organic matter metabolic fecal excretion was not affected by supplementation, suggesting a simultaneous increase in both passage (intake increase) and digestion rates (stable digestibility). The digestible organic matter intake showed a quadratic response with the increase of urea supplementation levels. The relationship between rumen degradable protein intake and digestible organic matter intake showed a maximization point, when rumen degradable protein intake was equivalent to 8.1% of digestible organic matter intake

Characteristics and clinical features of participants at study enrollment by pathogen detected, acute febrile illness study, May 7, 2012–May 6, 2015, Puerto Rico.

<p>Characteristics and clinical features of participants at study enrollment by pathogen detected, acute febrile illness study, May 7, 2012–May 6, 2015, Puerto Rico.</p

Number and proportion of enrolled participants by pathogens detected, overall and by age group, acute febrile illness study, May 7, 2012–May 6, 2015, Puerto Rico.

<p>Number and proportion of enrolled participants by pathogens detected, overall and by age group, acute febrile illness study, May 7, 2012–May 6, 2015, Puerto Rico.</p

Number of laboratory-positive dengue, chikungunya, influenza and other respiratory viral illness by month of illness onset, acute febrile illness study, May 7, 2012–May 6, 2015, Puerto Rico.

<p>Number of laboratory-positive dengue, chikungunya, influenza and other respiratory viral illness by month of illness onset, acute febrile illness study, May 7, 2012–May 6, 2015, Puerto Rico.</p

Early predictors of laboratory-positive dengue versus all other acute febrile illnesses by age group, acute febrile illness study, May 7, 2012–May 6, 2015, Puerto Rico.

<p>Early predictors of laboratory-positive dengue versus all other acute febrile illnesses by age group, acute febrile illness study, May 7, 2012–May 6, 2015, Puerto Rico.</p

Clinical and epidemiologic characteristics of dengue and other etiologic agents among patients with acute febrile illness, Puerto Rico, 2012–2015

<div><p>Identifying etiologies of acute febrile illnesses (AFI) is challenging due to non-specific presentation and limited availability of diagnostics. Prospective AFI studies provide a methodology to describe the syndrome by age and etiology, findings that can be used to develop case definitions and multiplexed diagnostics to optimize management. We conducted a 3-year prospective AFI study in Puerto Rico. Patients with fever ≤7 days were offered enrollment, and clinical data and specimens were collected at enrollment and upon discharge or follow-up. Blood and oro-nasopharyngeal specimens were tested by RT-PCR and immunodiagnostic methods for infection with dengue viruses (DENV) 1–4, chikungunya virus (CHIKV), influenza A and B viruses (FLU A/B), 12 other respiratory viruses (ORV), enterovirus, <i>Leptospira</i> spp., and <i>Burkholderia pseudomallei</i>. Clinical presentation and laboratory findings of participants infected with DENV were compared to those infected with CHIKV, FLU A/B, and ORV. Clinical predictors of laboratory-positive dengue compared to all other AFI etiologies were determined by age and day post-illness onset (DPO) at presentation. Of 8,996 participants enrolled from May 7, 2012 through May 6, 2015, more than half (54.8%, 4,930) had a pathogen detected. Pathogens most frequently detected were CHIKV (1,635, 18.2%), FLU A/B (1,074, 11.9%), DENV 1–4 (970, 10.8%), and ORV (904, 10.3%). Participants with DENV infection presented later and a higher proportion were hospitalized than those with other diagnoses (46.7% versus 27.3% with ORV, 18.8% with FLU A/B, and 11.2% with CHIKV). Predictors of dengue in participants presenting <3 DPO included leukopenia, thrombocytopenia, headache, eye pain, nausea, and dizziness, while negative predictors were irritability and rhinorrhea. Predictors of dengue in participants presenting 3–5 DPO were leukopenia, thrombocytopenia, facial/neck erythema, nausea, eye pain, signs of poor circulation, and diarrhea; presence of rhinorrhea, cough, and red conjunctiva predicted non-dengue AFI. By enrolling febrile patients at clinical presentation, we identified unbiased predictors of laboratory-positive dengue as compared to other common causes of AFI. These findings can be used to assist in early identification of dengue patients, as well as direct anticipatory guidance and timely initiation of correct clinical management.</p></div

Late predictors of laboratory-positive dengue versus all other acute febrile illnesses for all ages, acute febrile illness study, May 7, 2012–May 6, 2015, Puerto Rico^*.

<p>Late predictors of laboratory-positive dengue versus all other acute febrile illnesses for all ages, acute febrile illness study, May 7, 2012–May 6, 2015, Puerto Rico^{<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005859#t007fn001" target="_blank">*</a>}.</p