Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 17.394
Filtrar
1.
J Environ Qual ; 49(2): 324-334, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33016426

RESUMO

Managing a sustainable dairy farm requires balancing phosphorus (P) imports and exports that enter and leave through the farm gate. Over the long term, P surpluses will elevate soil-test P concentrations above crop requirements through routine land applications of manure. The objectives of this study were aimed at Virginia dairy farms (a) to determine P mass balances, (b) to define potential guidelines for a sustainable and feasible zone of operation based on P balance and P use efficiency, and (c) to assess risk factors driving P surplus and P use inefficiencies. Data on farm-gate P imports and exports via feed, manure, crops, fertilizers, bedding, animals, and milk were collected for 58 dairy farms in Virginia. There was no relationship between farm P balance and milk production, indicating that a P surplus was not necessary for good milk productivity. A feasible P balance limit was calculated below which 75% of farms could operate, and this was 18.7 kg P ha-1 . Two risk factors were identified for farms having a P balance above this limit: (a) land application of poultry litter and (b) excessive import of P through feed. Combined dairy and beef operations generally had more land and a lower P balance, whereas having combined dairy and poultry did not raise the P balance as long as poultry litter was exported. Dairy farms in Virginia can operate with a sustainable P balance as long as they avoid using excessive poultry litter and pay attention to P imported through purchased feed.


Assuntos
Indústria de Laticínios , Fósforo/análise , Ração Animal/análise , Animais , Bovinos , Fazendas , Nitrogênio/análise , Virginia
2.
J Environ Qual ; 49(5): 1384-1395, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33016445

RESUMO

Nutrients excreted from animals affect the nutritive value of manure as a soil amendment as well as the composition of gases emitted from manure storage facilities. There is a dearth of information, however, on how diet type in combination with dietary particle size affects nutrients deposited into manure storage facilities and how this affects manure composition and gas emissions. To fill this knowledge gap, an animal feeding trial was performed to evaluate potential interactive effects between feed particle size and diet composition on manure characteristics and manure-derived gaseous emissions. Forty-eight finishing pigs housed in individual metabolism crates that allowed for daily collection of urine and feces were fed diets differing in fiber content and particle size. Urine and feces were collected and stored in 446-L stainless steel containers for 49 d. There were no interactive effects between diet composition and feed particle size on any manure or gas emission parameter measured. In general, diets higher in fiber content increased manure nitrogen (N), carbon (C), and total volatile fatty acid (VFA) concentrations and increased manure VFA emissions but decreased manure ammonia emissions. Decreasing the particle size of the diet lowered manure N, C, VFAs, phenolics, and indole concentrations and decreased manure emissions of total VFAs. Neither diet composition nor particle size affected manure greenhouse gas emissions.


Assuntos
Dieta/veterinária , Esterco , Ração Animal/análise , Animais , Gases , Tamanho da Partícula , Suínos
3.
Vet Clin North Am Food Anim Pract ; 36(3): 745-774, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33032704

RESUMO

This review focuses on factors associated with mold production in feedstuffs and major mycotoxins affecting ruminants in North America. Ruminants are often considered less sensitive to mycotoxins owing to rumen microflora metabolism to less toxic compounds. However, ruminants occupy wide agricultural niches that expose animals to diverse toxins under widely different environmental and nutritional conditions. Often the moldy and potentially highly contaminated feeds end up at feedlots. Less than optimal feedstuffs creating suboptimal rumen microbial flora could result in decreased ruminal capacity to detoxify certain mycotoxins and adverse effects. Numerous mycotoxins and clinical effects in ruminants are discussed.


Assuntos
Produtos Agrícolas/microbiologia , Micotoxicose/veterinária , Micotoxinas/envenenamento , Doenças das Plantas/microbiologia , Ruminantes , Ração Animal/análise , Ração Animal/microbiologia , Animais , Micotoxicose/metabolismo , América do Norte
4.
Vet Clin North Am Food Anim Pract ; 36(3): 775-789, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32943303

RESUMO

Selenium (Se) is a metalloid that exists as a red amorphous powder, reddish crystal, silver-gray crystal, or brown-black solid. Its potency as a nutrient and a toxicant is such that few people have seen the pure element. It is easy to lose sight of the narrow margin between too little and too much. The most common cause of selenosis is accidental or intentional overuse of supplements. Many target organs and effects of Se toxicity are similar to those of Se deficiency, so laboratory confirmation is necessary. Prevention consists of minimizing exposure to seleniferous feedstuffs and optimizing dietary factors that might aggravate selenosis.


Assuntos
Envenenamento/veterinária , Ruminantes , Selênio/envenenamento , Ração Animal/análise , Ração Animal/envenenamento , Animais , Suplementos Nutricionais/análise , Suplementos Nutricionais/envenenamento , Envenenamento/etiologia
5.
Vet Clin North Am Food Anim Pract ; 36(3): 641-652, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32948411

RESUMO

Ionophores are a commonly used feed additive for animals and when used properly are safe. When feed mis-mixing occurs and an elevated dose of ionophore is given, a toxicosis can develop. Myocardial and skeletal muscles are the targets of a toxicosis. In many species there is a delay from the time of ingestion of a toxic dose in feed to when clinical signs occur. This makes it difficult to collect the feed in question that was at an elevated concentration. Cardiac troponins in serum can be used to make a diagnosis of an ionophore toxicosis.


Assuntos
Doenças dos Bovinos/induzido quimicamente , Ionóforos/administração & dosagem , Ionóforos/envenenamento , Ração Animal/efeitos adversos , Ração Animal/análise , Animais , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/metabolismo
6.
Vet Clin North Am Food Anim Pract ; 36(3): 653-659, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32948412

RESUMO

Corn co-products are a co-product of the dry and wet corn-milling ethanol manufacturing industry. The dry mill corn co-product is distiller's grains. Distillers grain can be further categorized into dry distillers grains (DDG), DDG with solubles, wet distillers grains with solubles (WDGS), modified WDGS, and corn syrup (solubles). Wet mill ethanol production produces 2 main feed stuffs: corn gluten (wet and dry) and heavy steep water.


Assuntos
Biocombustíveis/envenenamento , Doenças dos Bovinos/induzido quimicamente , Encefalomalacia/veterinária , Ração Animal/análise , Animais , Bovinos , Doenças dos Bovinos/metabolismo , Dieta/veterinária , Encefalomalacia/induzido quimicamente , Encefalomalacia/metabolismo , Sulfeto de Hidrogênio/metabolismo , Ruminantes , Zea mays/química
7.
Environ Monit Assess ; 192(9): 590, 2020 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-32820434

RESUMO

Organoarsenic compounds are widely used in chicken feed for control of coccidial parasite, quick weight gain, and for imparting attractive color to the chicken flesh. A study was conducted to assess the level of arsenic in both chicken feed and flesh. Chicken feed was collected from 10 farm houses and total arsenic was estimated. The quantitative estimation suggests that the four levels of chicken feed contain different quantities of arsenic load. The results demonstrated that feed at stages III and IV levels contain 0.01 mg/g and 0.018 mg/g of arsenic respectively. However, at stages I and II levels, the feed contains 0.005 mg/g and 0.0052 mg/g of arsenic respectively. Proceeding similarly, chicken flesh was collected from ten vendors in the local markets of Burdwan. The experimental results revealed that deposition of arsenic in different parts of chicken body is not same. The highest accumulation was recorded in the flesh of chest followed by stomach, whereas flesh of the legs and heart showed lower levels of arsenic accumulation. A comprehensive calculation was thereafter done to assess the total amount of arsenic ingestion through consumption of chicken. If a person takes 60.0 g of chicken flesh (leg, breast, muscles, and stomach) everyday, then the person may consume 0.186-0.372 µg of arsenic per day. This study therefore clearly suggests that excessive consumption of poultry chicken may prove to be fatal. However, further research is necessary to confirm the present findings. To the best of our knowledge, this is probably the first report on the likelihood of arsenic contamination in the flesh of different body parts of poultry chicken from Eastern India.


Assuntos
Arsênico/análise , Ração Animal/análise , Animais , Galinhas , Monitoramento Ambiental , Índia , Prevalência
8.
PLoS One ; 15(8): e0237262, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760129

RESUMO

The factors that influence the diversity and composition of raw milk and fecal microbiota in healthy commercial dairy herds are not fully understood, partially because the majority of metataxonomic studies involve experimental farms and/or single factors. We analyzed the raw milk and fecal microbiota of 100 healthy cows from 10 commercial alpine farms from the Province of Trento, Italy, using metataxonomics and applied statistical modelling to investigate which extrinsic and intrinsic parameters (e.g. herd, diet and milk characteristics) correlated with microbiota richness and composition in these relatively small traditional farms. We confirmed that Firmicutes, Ruminococcaceae and Lachnospiraceae families dominated the fecal and milk samples of these dairy cows, but in addition, we found an association between the number of observed OTUs and Shannon entropy on each farm that indicates higher microbiota richness is associated with increased microbiota stability. Modelling showed that herd was the most significant factor affecting the variation in both milk and fecal microbiota composition. Furthermore, the most important predictors explaining the variation of microbiota richness were milk characteristics (i.e. percentage fat) and diet for milk and fecal samples, respectively. We discuss how high intra-herd variation could affect the development of treatments based on microbiota manipulation.


Assuntos
Bactérias/isolamento & purificação , Bovinos/microbiologia , Indústria de Laticínios , Fezes/microbiologia , Leite/microbiologia , Ração Animal/análise , Animais , Bactérias/classificação , Dieta , Gorduras/análise , Feminino , Microbiota , Leite/química
9.
J Chromatogr A ; 1627: 461416, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823114

RESUMO

Animal feeds are often reported to be contaminated with chemical residues, and when present above the maximum legal limit, these compounds can cause harmful effects to consumers of animal produce. Thus, animal feed safety is an important regulatory concern. The aim of this study was to optimise a multiresidue method for the simultaneous analysis of multi-class pesticides and a number of frequently used veterinary drugs using LC-MS/MS and GC-MS/MS. The method was validated in a range of feed matrices, including maize feed, poultry feed and mixed feed concentrate. The optimised sample preparation workflow involved extraction of feeds (5 g) with ethyl acetate (10 mL), followed by a freezing step (at -20°C) used for eliminating the matrix co-extractives. The extract was further cleaned by dispersive solid phase extraction with a combination of primary secondary amine, C18 and florisil sorbents. From the cleaned-extract, an aliquot was analysed by GC-MS/MS, while another portion of it was solvent-exchanged to acetonitrile:water (50:50) and then analysed by LC-MS/MS. This method effectively minimised the matrix interferences. A total of 192 pesticides was analysed by GC-MS/MS within a runtime of 22 min. The LC-MS/MS method was validated for 187 compounds including 17 veterinary drugs. For most of the compounds, the limit of quantification (LOQ) was 0.01 mg/kg. The recoveries at LOQ and higher levels ranged between 70% and 120%, with precision-RSDs of < 20%. The method provided a precise analysis in a wide range of market-feed samples. As shown, the method is suitable for regulatory and commercial testing purposes.


Assuntos
Ração Animal/análise , Cromatografia Líquida/métodos , Praguicidas/análise , Espectrometria de Massas em Tandem/métodos , Drogas Veterinárias/análise , Animais , Congelamento , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Resíduos de Praguicidas/análise , Reprodutibilidade dos Testes , Solventes/química , Água/química
10.
Anim Sci J ; 91(1): e13438, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32761765

RESUMO

The objective was to investigate the influence of crude protein (CP) content in a fattening diet on feed intake, body weight gain, nitrogen excretion, and carcass traits in Holstein steers. Steers (initial body weight 241 ± 26 kg) consumed feed with the following CP content: (a) 17.7% during the early period (from 7 to 10 months of age) and 13.9% during the late period (from 11 to 18 months of age) (HIGH, n = 3), and (b) 16.2% during the early period and 12.2% during the late period (LOW, n = 4). The CP intake was lower in the LOW than the HIGH group. Urinary and total nitrogen excretion in the late period tended to be lower (p < .10) in the LOW than the HIGH group. However, growth performance and carcass traits were not affected by dietary CP content. Free histidine and total amino acid contents in the longissimus thoracis muscle tended to be higher (p < .10) in the HIGH than the LOW group, however, the CP contents were not affected by dietary CP content. The results of this experiment suggest that decreasing dietary CP to 16% (early period) or 12% (late period) of dry matter would reduce nitrogen excretion from Holstein fattening farms without affecting productivity.


Assuntos
Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Bovinos/metabolismo , Bovinos/fisiologia , Dieta/veterinária , Proteínas na Dieta/análise , Nitrogênio/metabolismo , Ganho de Peso , Animais , Masculino
11.
PLoS One ; 15(8): e0237505, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790727

RESUMO

Increased intestinal permeability (IP) and inflammation are both linked with functionality of the intestinal barrier and in particular enterocytes. Currently, almost all assessment methods of the intestinal barrier function are invasive. The present study aimed to quantify selected proteins as novel biomarkers in excreta of broiler chickens to facilitate non-invasive assessment of gut barrier function using enzyme-linked immunosorbent assays (ELISA). It was further hypothesised that probiotics as feed additives may counteract gut barrier dysfunction. A 3 × 2 factorial arrangement of treatments was used with the main factors being gut barrier dysfunction models (control, rye-based diet, and dexamethasone-DEX) with and without probiotic supplementation (a three-strain Bacillus) using 72 male Ross 308 day-old chickens. Each of the 6 experimental treatments was replicated 12 times. On d 21 of age, fluorescein isothiocyanate dextran (FITC-d) uptake into serum was examined to test IP. Fresh excreta samples were collected on d 20. The biomarkers included alpha-1 antitrypsin (A1AT), intestinal fatty acid binding protein (I-FABP), lipocalin-2 (LCN2), fibronectin (FN), intestinal alkaline phosphatase (IAP), ovotransferrin (OVT) and superoxide dismutase [Cu-Zn] (SOD1). Only DEX increased (P<0.001) FITC-d passage to the blood on d 21 of age, indicating a greater IP. The excreta concentrations of A1AT, I-FABP and SOD1 were unaltered by the experimental treatments. DEX increased (P<0.05) FN concentration in excreta compared with control birds. Conversely, inclusion of rye in the diet reduced (P<0.05) FN but increased (P<0.001) OVT in excreta. Independently, DEX decreased IAP (P<0.05) in excreta compared with control and rye-fed birds. The excreta concentration of LCN2 tended (P = 0.086) to increase in birds injected by DEX. There was no demonstrable effect of probiotic addition on any of the studied parameters. Among the tested biomarkers, FN, IAP, and LCN2 revealed promise as biomarkers of intestinal barrier function quantified by ELISA kits.


Assuntos
Ração Animal/análise , Biomarcadores/análise , Dieta/veterinária , Fezes/química , Microbioma Gastrointestinal/efeitos dos fármacos , Intestinos/patologia , Probióticos/farmacologia , Animais , Permeabilidade da Membrana Celular , Galinhas , Suplementos Nutricionais , Intestinos/efeitos dos fármacos , Masculino
12.
Sci Total Environ ; 746: 140788, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32758982

RESUMO

We tested the effect of increasingly diverse combinations of tanniferous legumes (birdsfoot trefoil-BFT, sainfoin-SF) and alfalfa (ALF) on cattle performance, methane (CH4) emissions and nitrogen (N) balance. Pairs of heifers (401 ± 49.6 kg) grazed three spatial replications of 7 treatments (n = 3/treatment): monocultures (BFT, SF, ALF) and all possible 2- and 3-way choices among strips of these legumes in a completely randomized block design of two 15-d periods during 2 consecutive years. Average daily gains (ADG) of heifers grazing the tanniferous legumes (1.05 kg/d) were 40% greater (p < 0.10) than of heifers grazing ALF (0.74 kg/d) during the first year. Heifers grazing the 3-way choice had greater intakes (10.4 vs 7.8 kg/d; p = 0.064) and ADG (1.21 vs. 0.95 kg/d, p = 0.054) than those grazing monocultures, suggesting a nutritional synergism among legumes. The average CH4 emissions for legume monocultures vs. 2- and 3- way choices was 222 vs. 202 and 162 g/kg BW gain (p > 0.10), respectively. For heifers grazing SF and BFT compared with ALF, blood urea N was less (14.3 and 16.8 vs 20.8 mg/dL; p < 0.05) as were urinary N concentrations (3.7 and 3.5 vs 6.0 g/L; p < 0.05), but fecal N concentrations were greater (34.5 and 35.5 vs 30.5 g/kg, respectively; p < 0.05). Combining both tanniferous legumes (SF-BFT) led to the greatest declines in urinary N (2.24 g/L) and urea-N (1.71 g/L) concentration, suggesting that different types of tannins in different legumes result in associative effects that enhance N economy. In addition, heifers grazing 3-way choices partitioned less N into urine (40.7 vs 50.6%; p = 0.037) and retained more N (36.1 vs 25.2%, p = 0.046) than heifers grazing monocultures. In summary, combinations of tanniferous legumes with alfalfa improved animal performance and reduced environmental impacts relative to monocultures, resulting in a more sustainable approach to beef production in pasture-based finishing systems.


Assuntos
Ração Animal/análise , Dieta , Animais , Bovinos , Meio Ambiente , Feminino , Medicago sativa , Taninos
13.
Environ Pollut ; 266(Pt 3): 115156, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32663629

RESUMO

The aquatic ecosystem is seriously damaged because of the heavy use of pesticides and antibiotics. Fish is the indispensable link between environmental pollution and human health. However, the toxic effects of environment-related concentrations of pesticides and antibiotics in fish have not been thoroughly studied. In this study, grass carps exposed to cypermethrin (CMN, 0.651 µg/L) or/and sulfamethoxazole (SMZ, 0.3 µg/L) for 42 days caused oxidative stress, apoptosis and immunodeficiency in the spleen of grass carps. CMN or/and SMZ exposure led to oxidative damage (consumption of antioxidant enzymes (superoxide dismutase and catalase)) and lipid peroxidation (accumulation of malondialdehyde), induced apoptosis (increases in TUNEL index, Bax/bcl-2, p53, puma and Caspase family expression). In addition, the levels of immunoglobulin M (IgM), complement 3 (C3) were significantly decreased in all treatment groups, which trend was also found in C-reactive protein in CMN and MIX group, and lysozyme in MIX group. Transcription of almost all genes involved in the Toll-like receptors (TLR) signaling pathway was up-regulated under CMN or/and SMZ exposure. However, when subsequently attacked by Aeromonas hydrophila for 2 days, the TLR pathway was inhibited in spleens of all treatment groups accompanied by higher mortality. Overall, the environmentally relevant concentration of CMN and SMZ damages the immune system, triggering oxidative stress and apoptosis in carps. And by affecting the conduction of TLR signaling pathway, CMN or/and SMZ exposure inhibits the innate immune response of fish and reducing their disease resistance. This study highlights the importance of rational and regulated use of these pesticides and antibiotics.


Assuntos
Carpas , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Ursidae , Aeromonas hydrophila , Ração Animal/análise , Animais , Dieta , Ecossistema , Proteínas de Peixes , Imunidade Inata , Piretrinas , Sulfametoxazol
14.
Environ Sci Pollut Res Int ; 27(30): 37677-37683, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32608001

RESUMO

The study aimed to investigate the effect of Se sources and concentrations on performance, thyroid activity, antioxidant defense, and functional egg quality of Japanese quail. One hundred and twenty, 8-week-old birds were randomly assigned to 1 of 4 dietary treatments in 3 replicates (10 birds/replicate). The treatments contained inorganic sodium selenite (SS) at 0.2 mg/kg diet (SS1 = control) or 0.4 mg/kg diet (SS2) or selenomethionine (SM) at 0.2 mg/kg diet (SM1) or 0.4 mg/kg diet (SM2). Egg production (%) and feed intake were daily recorded, and feed conversion ratio (FCR) was calculated. Blood samples were collected and analyzed for glucose, thyroxine (T4), triiodothyronine (T3), glutathione peroxidase (GPX), and superoxide dismutase (SOD) enzymes. Egg quality was determined in terms of Se content and concentrations of triglycerides, LDL, HDL, and cholesterol. Dietary supplementation of SM2 increased (P < 0.05) egg production (%) and egg mass and decreased FCR compared to the other groups, which showed no significant differences (P > 0.05) in between. It is the first study reporting that the eggs from the quail fed SM2 diet had lower concentrations (P < 0.05) of triglycerides, LDL, and cholesterol than those fed SS. Feeding SM increased (P < 0.05) blood glucose, T4, and T3 levels. Moreover, feeding SM increased the activity of GPX and SOD with a higher significance (P < 0.05) for SM2 than SM1. In conclusion, no adverse effects from supplementation of SM up to 0.4 mg/kg were observed and could improve their performance, antioxidant defense, thyroid activity, and functional egg quality.


Assuntos
Antioxidantes , Coturnix , Ração Animal/análise , Animais , Dieta , Suplementos Nutricionais , Ovos
15.
PLoS One ; 15(7): e0234610, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645008

RESUMO

The objective of this study was to evaluate the effect of the physical form of starter and inclusion of hay in the diet of preweaning dairy calves on performance, digestibility, ruminal development, and mRNA expression of genes involved in ruminal metabolism. Holstein × Gyr crossbred male calves (n = 38 1day old) were assigned to 3 treatments for 9 weeks: Control (n = 13; pellet starter with 4 mm diameter and 18 mm length and 4% steam-flaked corn), Ground (n = 12; same starter of the control but ground pass through a 4.0 mm sieve), or Ground plus 5% chopped Tifton hay GH (n = 13). All calves were fed 4 L/d of whole milk up to 63 d of age and were abruptly weaned at 64 d of age. Water and diets were offered ad libitum. Samples of ruminal contents were obtained from all animals at 30, 45, and 60 d of age to evaluate pH, ammonia nitrogen, and volatile fatty acids (VFA). At 55 d of age, an apparent digestibility assay was performed using 18 animals (n = 6/ treatment). At 65 d of age, the 18 animals were euthanized to evaluate the development of the digestive tract. The physical form of starter and the dietary inclusion of hay did not influence starter intake (Control 326 g/d, Ground 314 g/d and GH 365 g/d), daily weight gain (Control 541g/d, Ground 531g/d and GH 606g/d), feed efficiency, apparent nutrient digestibility, energy partitioning, nitrogen balance, ruminal pH, ammonia nitrogen concentration, VFA, the development of the digestive tract and the mRNA expression of genes involved in AGV metabolism.


Assuntos
Ração Animal/análise , Criação de Animais Domésticos/métodos , Dieta/veterinária , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Peso Corporal , Bovinos , Fibras na Dieta/metabolismo , Masculino , Leite/metabolismo , Nutrientes , Rúmen/metabolismo , Desmame , Ganho de Peso , Zea mays/metabolismo
16.
Br Poult Sci ; 61(4): 471-481, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32683884

RESUMO

1. This study quantified xylanase-induced changes in soluble monosaccharides, xylooligosaccharides (XOS) and volatile fatty acid (VFA) contents of the different sections of the gastrointestinal tract (GIT) and whether these were related to altered bird performance. 2. An in vitro digestion of the wheat-based diet was carried out with the xylanase (Econase XT at 16,000BXU/kg diet) to compare the in vitro and in vivo generation of these XOS and monosaccharides. For the in vivo study, 80 male Ross 508 b roiler chicks were split into two groups fed a wheat-based diet with or without Econase XT (16,000BXU/kg diet) for 21 days. 3. There were no effects of Econase XT inclusion on growth performance characteristics, likely a result of the high-quality wheat diet, the corresponding high performance of the control group (FCR average of 1.45 in controls) and the relatively young age of the birds (from four to 26 days of age). 4. Econase XT supplementation increased the xylotetraose (X4) content in the colon (P = 0.046, enzyme x GIT section interaction) and the xylose contents in the colon and caeca (P < 0.001, enzyme x GIT section interaction). 5. The trend for increased acetate production in the caeca of Econase XT treated birds (P = 0.062) suggested that the XOS generated were subsequently fermented in the caeca, potentially impacting upon the types of microbiota present. 6. The present study suggested that wheat arabinoxylan degradation was enhanced by xylanase supplementation, which may have increased the production of beneficial volatile fatty acids (VFA) in the caeca, and thereby potentially modulated the caecal microbiome, but without affecting bird performance at this early age.


Assuntos
Galinhas , Triticum , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta , Suplementos Nutricionais , Digestão , Endo-1,4-beta-Xilanases , Glucuronatos , Masculino , Monossacarídeos , Oligossacarídeos
17.
PLoS One ; 15(7): e0229314, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32706777

RESUMO

INTRODUCTION: Many arboviruses of public health significance are maintained in zoonotic cycles with complex transmission pathways. The presence of serum antibody against arboviruses in vertebrates provides evidence of their historical exposure but reveals nothing about the vector-reservoir relationship. Moreover, collecting blood or tissue samples from vertebrate hosts is ethically and logistically challenging. We developed a novel approach for screening the immune status of vertebrates against Ross River virus that allows us to implicate the vectors that form the transmission pathways for this commonly notified Australian arboviral disease. METHODS: A micro-plaque reduction neutralisation test (micro-PRNT) was developed and validated on koala (Phascolarctos cinereus) sera against a standard PRNT. The ability of the micro-PRNT to detect RRV antibodies in mosquito blood meals was then tested using two mosquito models. Laboratory-reared Aedes aegypti were fed, via a membrane, on sheep blood supplemented with RRV seropositive and seronegative human sera. Aedes notoscriptus were fed on RRV seropositive and seronegative human volunteers. Blood-fed mosquitoes were harvested at various time points after feeding and their blood meals analysed for the presence of RRV neutralising antibodies using the micro-PRNT. RESULTS: There was significant agreement of the plaque neutralisation resulting from the micro-PRNT and standard PRNT techniques (R2 = 0.65; P<0.0001) when applied to RRV antibody detection in koala sera. Sensitivity and specificity of the micro-PRNT assay were 88.2% and 96%, respectively, in comparison with the standard PRNT. Blood meals from mosquitoes fed on sheep blood supplemented with RRV antibodies, and on blood from RRV seropositive humans neutralised the virus by ≥50% until 48 hr post feeding. The vertebrate origin of the blood meal was also ascertained for the same samples, in parallel, using established molecular techniques. CONCLUSIONS: The small volumes of blood present in mosquito abdomens can be used to identify RRV antibodies and therefore host exposure to arbovirus infection. In tandem with the accurate identification of the mosquito, and diagnostics for the host origin of the blood meal, this technique has tremendous potential for exploring RRV transmission pathways. It can be adapted for similar studies on other mosquito borne zoonoses.


Assuntos
Aedes/metabolismo , Ração Animal/análise , Anticorpos Antivirais/análise , Testes de Neutralização/métodos , Vírus do Rio Ross/imunologia , Aedes/virologia , Infecções por Alphavirus/diagnóstico , Infecções por Alphavirus/transmissão , Infecções por Alphavirus/veterinária , Ração Animal/virologia , Animais , Anticorpos Antivirais/sangue , Vetores de Doenças , Feminino , Humanos , Phascolarctidae/virologia , Sensibilidade e Especificidade
18.
Ecotoxicol Environ Saf ; 203: 110899, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32678747

RESUMO

Liver is the earliest target for AFB1 toxicity in both human and animals. In the last decade, plant derived by-products have been used in animal feed to reduce AFB1 induced toxicity. In the present study we investigated whether the presence of 8% grape seed meal by-product is able to counteract the hepatotoxic effects produced by AFB1 in liver of pig after weaning exposed to the toxin through the contaminated feed for 28 days. Twenty four weaned cross-bred TOPIGS-40 piglets with an average body weight of 9.13±0.03 were allocated to the following experimentally treatments: control diet without AFB1 (normal compound feed for weaned pigs); contaminated diet with 320 mg kg-1 AFB1; GSM diet (compound feed plus 8% grape seed meal) and AFB1+GSM diet (320 mg kg-1 AFB1 contaminated feed plus 8% grape seed meal). Pigs fed AFB1 diet had altered performance, body weight decreasing with 25.1% (b.w.: 17.17 kg for AFB1 vs 22.92 kg for control). Exposure of piglets to AFB1 contaminated diet caused liver oxidative stress as well as liver histological damage, manly characterized by inflammatory infiltrate, fibrosis and parenchyma cells vacuolation when compared to control and GSM meal group. 94.12% of the total analysed genes (34) related to inflammation and immune response was up-regulated. The addition of GSM into the AFB1 diet diminished the gene overexpression and ameliorate histological liver injuries and oxidative stress. The protective effect of GSM diet in diminishing the AFB1 harmful effect was mediated through the decreasing of gene and protein expression of MAPKs and NF-κB signalling overexpressed by AFB1 diet. The inclusion of grape seed by-products in the diet of pigs after weaning might be used as a novel nutritional intervention to reduce aflatoxin toxicity.


Assuntos
Aflatoxina B1/toxicidade , Ração Animal/análise , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Fígado/efeitos dos fármacos , Sementes/química , Vitis/química , Animais , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Dieta , Fígado/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Suínos , Desmame
19.
PLoS One ; 15(7): e0236118, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32667943

RESUMO

The objective of this study was to evaluate whether pre-weaning heifer calves divergent for residual feed intake (RFI) or residual feed intake and body weight gain (RIG) exhibit differences in thermography, blood, and ruminal parameters. Thirty-two Gyr heifer calves were enrolled in a 63-d trial and classified into 2 feed efficiency (FE) groups based on RFI and RIG (mean ± 0.5 SD). The groups were classified as high efficiency (HE) RFI (HE RFI, n = 9), HE RIG (HE RIG, n = 10), low efficiency (LE) RFI (LE RFI, n = 10), and LE RIG (LE RIG, n = 11). The amount of whole milk provided for each calf was calculated based on their metabolic weight at birth (42% x BW0.75). The liquid diet was divided into two meals at 0700 and 1400 h. The total solid diet (TSD) was composed of 92% concentrate and 8% of Tifton 85 hay chopped in 5-cm lengths, as fed. Intake was measured daily. Blood concentrations of insulin, beta hydroxybutyrate, urea, and glucose, and ruminal pH, N-NH3, and volatile fatty acids (VFA) were evaluated at 14, 28, 42, 56, and 70 days of age. Thermal images of the calves were taken with an infrared camera (FLIR T420, FLIR Systems Inc., Wilsonville, OR) on d 56 (±3) at 0600 h, before the morning feeding. Total VFA concentration and propionate as % of total VFA were 24.2% and 22.2% lower in HE RFI compared to LE RFI calves, respectively. On the other hand, acetate as % of total VFA was 10.6% greater in HE RFI than LE RFI calves. Blood urea concentration tended to be greater in LE RFI than HE RFI calves. High efficiency HE RIG tended to have 6.8% greater acetate and 15.4% lower propionate as % of total VFA than LE RIG. Blood insulin concentration was greater and blood glucose tended to be greater for LE RIG than HE RIG group. Low efficiency RIG group had greater left rib, left flank, and anus surface temperature measured by infrared thermography than the HE RIG group. Differences in ruminal fermentation do not seem to be associated with pre-weaning calves efficiency, while differences in protein metabolism seem to affect RFI during this phase. Infrared thermography appears to be correlated to RIG in pre-weaning heifer calves.


Assuntos
Ração Animal/análise , Dieta/veterinária , Comportamento Alimentar/fisiologia , Termogênese , Desmame , Ganho de Peso , Animais , Células Sanguíneas/metabolismo , Bovinos , Ingestão de Energia , Ruminantes/metabolismo , Termografia
20.
Environ Sci Pollut Res Int ; 27(31): 38607-38616, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32623680

RESUMO

A 42-day comparative study was conducted to assess the impact of nanoselenium to other selenium sources on performance, antioxidant activity, immunity, and carcass traits in broilers. Ross 308 (n = 156) 1-day-old broiler chicks, with average initial body weight of 45.80 ± 0.35, were randomly allocated to 4 groups. The first group (G1) fed the basal diet without selenium supplementation. The second group (G2), the third group (G3), and the fourth group (G4) were supplemented with dietary selenium at the level of 0.3 mg kg-1 diet in the form of sodium selenite, seleno-methionine, and nanoselenium, respectively. The results revealed significant improvement on most of the performance parameters of nanoselenium at the level of 0.3 mg kg-1 diet (P < 0.05). Nanoselenium and seleno-methionine achieved the best dressing %, spleen index %, and thymus index %. Concerning to internal organ indices, none of these indices was significantly affected by any selenium sources (P < 0.05). Glutathione peroxidase (GSH-PX) activity and malondialdehyde (MDA) content were not significantly affected by different selenium sources among all experimental groups. Serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) showed significant (P < 0.05) decrease in nanoselenium supplemented group compared with other groups. In case of serum IL-10 level, a significant (P < 0.05) increase was reported in nanoselenium supplemented group followed by G3 then G2. There were no statistical differences in the serum alanine transaminase, aspartate transaminase, total protein, albumin concentration, serum creatinine level, and uric acid concentration levels among all experimental groups. It is concluded that nano selenium can be a useful and better source of selenium for broilers.


Assuntos
Galinhas , Selênio/farmacologia , Ração Animal/análise , Animais , Antioxidantes , Galinhas/crescimento & desenvolvimento , Dieta , Suplementos Nutricionais , Glutationa Peroxidase
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA