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1.
Anim Cogn ; 21(3): 393-405, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29532262

RESUMO

There is evidence that wild animals are able to recall key locations and associate them with navigational routes. Studies in primate navigation suggest most species navigate through the route network system, using intersections among routes as locations of decision-making. Recent approaches presume that points of directional change may be key locations where animals decide where to go next. Over four consecutive years, we observed how a wild group of bearded capuchin monkeys used a route network system and Change Point locations (CPs) in the Brazilian ecotone of Cerrado-Caatinga. We built 200 daily routes of one wild bearded capuchin group. We used ArcGIS, the Change Point Test, Spatial Analysis in Macroecology (SAM), and statistical models to test the hypothesis that wild bearded capuchins use CPs located along routes in a different fashion than they use the CPs located at intersections of routes. A logistic regression model was used to determine the landscape variables affecting capuchins' directional changes at intersections or along routes. CPs at intersections were important points of travel path changes, whereas CPs along routes represented a zig-zag movement along the routes following the landscape features. CPs at intersections were associated with steeper terrains and shorter distances from important resources, along with better visibility of the home range. Our results support the hypothesis that intersections among routes in the route network system are located at points where monkeys have the best visibility available to make decisions on where to visit next.


Assuntos
Cebus/fisiologia , Navegação Espacial , Animais , Comportamento Apetitivo , Brasil , Cognição , Feminino , Geografia , Locomoção , Modelos Logísticos , Masculino
2.
Rapid Commun Mass Spectrom ; 30(1): 170-4, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26661984

RESUMO

RATIONALE: In meat production it is common practice to use finishing diets based on concentrates, even for those animals previously raised on pasture. No studies have investigated the variations of stable isotope ratios in lamb plasma and erythrocytes, following a switch from pasture to a concentrate-based diet during the last days before slaughter. For meat traceability it is important to verify how and whether these parameters are affected in blood fractions. METHODS: Blood of ten male Italian Merino lambs, whose diet was switched from pasture to concentrate, was sampled 8 times (days 1, 2, 3, 4, 5, 6, 7 and 14) in the last 14 days before slaughter. The variations in the δ(13)C, δ(15)N, δ(18)O and δ(34)S values of blood plasma and erythrocytes were investigated. The stable isotope ratios of the samples were measured using a stable isotope mass spectrometer coupled with an elemental analyser (C, N, S) and a CO2/H2O equilibration system (O(plasma)). RESULTS: The δ(13) C(plasma), δ(18)O(plasma) and δ(34)S(plasma) values were shown to be different 7 days after the abrupt variation in the diet. The comparison between erythrocytes and plasma stable isotope ratios could be suitable for verifying whether the animal was actually pasture-raised and could merit a higher price. The erythrocytes isotopic signature was not affected by very short finishing periods in previously grazed animals and maintained the pasture-raised fingerprint, while the analysis of plasma could detect very short finishing periods with concentrate and hay. CONCLUSIONS: The present study has demonstrated that the combination of blood plasma and erythrocytes stable isotope ratios of carbon, nitrogen, oxygen and sulphur can be used to infer the dietary background of lambs and thus offers a tool for the authentication of the animal production system.


Assuntos
Isótopos de Carbono/sangue , Dieta , Isótopos de Nitrogênio/sangue , Ração Animal , Animais , Masculino , Espectrometria de Massas , Ovinos
3.
Front Pediatr ; 10: 1088773, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36683824

RESUMO

Kawasaki disease (KD) is one of the most frequent idiopathic vasculitis in children, affecting medium- and small-sized vessels. Multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 has recently emerged as a new systemic hyperinflammatory condition affecting children some weeks after an acute COVID-19 infection. KD and MIS-C share different aspects and differ in many others: patients affected by MIS-C are usually older, with prominent gastrointestinal manifestations, diffuse adenopathy, extensive conjunctivitis, myocardial damage, leukopenia, and thrombocytopenia at the laboratory exams. Both conditions can present neurological complications. The aim of this manuscript is to provide a narrative review of neurological involvement in KD and MIS-C. A comprehensive review literature has been performed, and the main clinical features have been analyzed, contributing to neurological differential diagnosis.

4.
Behav Processes ; 173: 104064, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32006621

RESUMO

The study of traits that enable species to thrive in urban habitats is critical to a better understanding the evolution of urban ecosystems. Here, we examined variation in boldness, neophobia, and exploratory behavior in a generalist raptor, the Chimango Caracara, Milvago chimango, occurring in areas with different urbanization level. We also focused on the relationship between object exploration and neophobia in rural and urban population of this species. The results showed that birds from more urbanized habitats showed more tolerance to humans than rural raptors, without any effect of age and sex in this trait. Rural birds were also more neophobic and were slower to explore than urban raptors, though they dedicated a similar amount of time to exploring novel objects, indicating a non-correspondence between the speed to approach and contact these objects and the amount of exploration performed. Finally, we found a correlation between exploration speed and neophobia in rural birds, whereas for urban raptors this correlation was not observed. Our results show that urbanization not only influences the expression of risk-taking behaviors and novelty responses in the chimango, but can also modify the relationship between exploration and neophobia.


Assuntos
Comportamento Exploratório/fisiologia , Falconiformes/fisiologia , Assunção de Riscos , Animais , Ecossistema , Feminino , Masculino , Fenótipo , Urbanização
5.
Meat Sci ; 81(1): 120-5, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22063971

RESUMO

Fourteen male Comisana lambs were divided into two groups at 45days of age: lambs fed a concentrate diet (C), or lambs fed the same concentrate with the addition of quebracho (Schinopsis lorentzii) tannins (T). Sheep were slaughtered at 105days of age. Lipid oxidation, colour coordinates, haem pigment concentration, and metmyoglobin percentages were measured on minced semimembranosus muscle (SM) over 14days of refrigerated storage in a high oxygen modified atmosphere. Tannin supplementation increased (P<0.01) a(∗) values and reduced (P<0.01) b(∗) values of the SM when compared to C. Lower hue angles (P<0.001) and metmyoglobin formation (P=0.07) were observed in lamb from T-fed compared to C-fed sheep during the 14-days storage period. Furthermore, feeding T resulted in greater (P<0.001) haem pigment concentrations in the SM during refrigerated storage; however, diet had no (P=0.28) effect on lipid oxidation. Therefore, including quebracho tannins in sheep diets can improve meat colour stability of fresh lamb during extended refrigerated storage.

6.
Materials (Basel) ; 12(6)2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30897731

RESUMO

The reinforced concrete structures that support transport, energy and urban networks in developed countries are over half a century old, and are facing widespread deterioration. Geopolymers are an affordable class of materials that have promising applications in concrete structure coating, rehabilitation and sensing, due to their high chloride, sulphate, fire and freeze-thaw resistances and electrolytic conductivity. Work to date has, however, mainly focused on geopolymers that require curing at elevated temperatures, and this limits their ease of use in the field, particularly in cooler climates. Here, we outline a design process for fabricating ambient-cured fly ash geopolymer coatings for concrete substrates. Our technique is distinct from previous work as it requires no additional manufacturing steps or additives, both of which can bear significant costs. Our coatings were tested at varying humidities, and the impacts of mixing and application methods on coating integrity were compared using a combination of calorimetry, x-ray diffraction and image-processing techniques. This work could allow geopolymer coatings to become a more ubiquitous technique for updating ageing concrete infrastructure so that it can meet modern expectations of safety, and shifting requirements due to climate change.

7.
Behav Processes ; 157: 250-255, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30359692

RESUMO

Birds exhibit variation in fear behaviour in response to an approaching human within and between species and across different habitat contexts. We analyze urban and rural burrowing owls' variation in risk perception along separate but consecutive days (Treatment 1) and risk perception within the same day (Treatment 2). Fear behaviour was measured as flight initiation distances (FIDs) and aggressiveness level when a pedestrian approached repeatedly to an owl individual. We predict that the attenuation in fear response along treatments should add support to the habituation hypothesis (decrease the response to a repeatedly stimulus after verifying that it is irrelevant) while consistency in behaviour might be indicative of a personality trait. We found that FID decreased for measurements made on both treatments in rural owls and also in urban owls for Treatment 2. These results are compatible with a habituation process. We found that aggressiveness remained invariable along treatments in both habitats suggesting that different mechanisms underlie these behavioural responses. Our results suggest that owls' risk perception to humans can be adjusted based on environmental risk perception and that individuals are able to recognize and learn when a stimuli stops being a threat.


Assuntos
Agressão/fisiologia , Comportamento Animal/fisiologia , Ecossistema , Medo/fisiologia , Habituação Psicofisiológica/fisiologia , Estrigiformes/fisiologia , Animais , Argentina , Feminino , Humanos , Masculino
8.
J Anim Sci ; 93(6): 3179-88, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26115304

RESUMO

In the present study, we have hypothesized that replacing barley with high proportions of dried citrus pulp in a concentrate-based diet for lambs could increase the intake of unsaturated fatty acids and could reduce the rate of the ruminal biohydrogenation of PUFA, with a consequent improvement of the intramuscular fatty acid composition. To test this hypothesis, 26 Comisana lambs were divided into 3 groups and for 56 d were fed a barley-based concentrate diet (CON; 8 lambs) or 2 diets in which barley was replaced with 24% (CIT24; 9 lambs) or 35% (CIT35; 9 lambs) dried citrus pulp. An overall improvement of the fatty acid composition of LM from lambs fed citrus pulp-containing diets was found. The PUFA/SFA ratio was lower (P < 0.05) in the LM from lambs in the CON group compared with both the CIT24 and CIT35 groups. The thrombogenic index was lower (P < 0.05) in meat from lambs fed the CIT35 diet compared with those fed the CON diet. The CIT35 diet increased the proportion of C20:5 n-3 in the LM (P < 0.05), whereas the CIT24 diet enhanced that of C22:6 -3 (P < 0.05) compared with the CON diet. Some of these results might be explained considering that feeding the CIT24 and CIT35 diets increased the intake of total fatty acids (P < 0.05) and of C18:3 n-3 (P < 0.01) compared with feeding the CON treatment. On the other hand, phenolic compounds present in citrus pulp could have inhibited the ruminal biohydrogenation of PUFA. This is supported by the fact that regardless of the level of inclusion in the diet, citrus pulp increased the proportion of rumenic acid (P < 0.001) in LM compared with the CON diet. The plasma from lambs fed both CIT24 and CIT35 diets had a greater percentage of vaccenic acid (VA; < 0.001) compared with that from lambs fed the CON diet, and the CIT35 diet increased the proportion of rumenic acid in plasma compared with the CON treatment (P < 0.05). In the ruminal fluid, stearic acid (SA) tended to decrease, and the sum of CLA tended to increase (P = 0.09) with increasing level of citrus pulp in the diets. Furthermore, the SA/(SA + VA) ratio tended to be lower (P = 0.10) in the ruminal fluid from lambs fed the CIT35 diet compared with that of the CON group. In conclusion, our results support the hypothesis that replacing barley with citrus pulp in the diet of growing lambs improves intramuscular fatty acid composition and underline the need for specific studies to clarify the mechanisms by which feeding citrus pulp affects the fatty acid metabolism in ruminants.


Assuntos
Ração Animal/análise , Citrus/química , Dieta/veterinária , Ovinos/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Animais , Líquidos Corporais , Citrus/metabolismo , Ácidos Graxos/metabolismo , Ácidos Linoleicos Conjugados/metabolismo , Metabolismo dos Lipídeos , Músculo Esquelético/química
9.
Artigo em Inglês | MEDLINE | ID: mdl-11370995

RESUMO

1. The authors present here a sensitive and rapid reversed-phase liquid chromatographic method which enables the simultaneous analysis in plasma of two different drugs and their metabolites: the atypical neuroleptic clozapine and the tricyclic antidepressant clomipramine. 2. Samples and the internal standard (dibenzepine) were extracted through automated solid-phase procedure, evaporated dryness and injected into the chromatograph. Mobile phase was a mixture of water and acetonitrile (63:37, v:v) containing TEMED and triethylamine. The total chromatographic time was of 14 min and analyte peaks were detected by means of an ultraviolet spectrophotometer preset at 254 nm. 3. Results revealed an assay sensitivity of 5 microg/L for clozapine or norclozapine and of 10 microg/L for clomipramine and desmethylclomipramine. Recoveries for these drugs and their metabolites were more than 60% and their coefficient of variation (within day and day-to-day) ranged from 1.3 % to 2.5 %. In spiked plasma, within day and day-to-day coefficients of variability (CV) were less than 5%. The simultaneous evaluation of these two drugs with adequate sensitivity and precision makes it particularly useful for therapeutic drug monitoring during mono- or polypharmacotherapy.


Assuntos
Antidepressivos Tricíclicos/sangue , Clomipramina/sangue , Clozapina/sangue , Cromatografia Líquida/métodos , Clomipramina/análogos & derivados , Clozapina/análogos & derivados , Feminino , Humanos , Análise dos Mínimos Quadrados , Modelos Lineares , Masculino
10.
Int J Biol Macromol ; 12(1): 41-9, 1990 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2083240

RESUMO

Sequential glycopeptides [Thr(beta-D-galactose)-Ala-Ala]n, with n ranging from 2 to 7, as models of natural antifreeze glycoproteins were synthesized by the continuous flow, solid phase procedure. The conformational properties of these materials in solution were investigated by c.d. and 1H-n.m.r. spectroscopy. In aqueous solution the c.d. pattern is practically independent of chain length and is very similar to that of natural antifreeze glycoproteins. The results are interpreted in terms of random coil structure. The absence of ordered structures is further confirmed by n.m.r. data. A small amount of ordered conformation can be induced either by increasing the temperature of the aqueous solution or by addition of TFE. The c.d. pattern of all glycopeptides in water at temperatures higher than 50 degrees C are compatible with the presence of a small amount of alpha-helix or 3(10) helix. Since the glyco-hexapeptide is too short to form an alpha-helix, the hypothesis is made that in the glycopeptides in water at high temperature a small amount of 3(10) helix is formed. The same is observed for the 21-residue glycopeptide in presence of 85% (v/v) TFE. In this medium, the c.d. data on the glyco-hexapeptide are more compatible with the presence of a small amount of beta-structure.


Assuntos
Glicopeptídeos/química , Glicoproteínas/química , Proteínas Anticongelantes , Dicroísmo Circular , Congelamento , Glicopeptídeos/síntese química , Glicoproteínas/síntese química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Conformação Proteica , Temperatura , Água/química
11.
J Anim Sci ; 78(4): 810-6, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10784169

RESUMO

We conducted an experiment to evaluate the effects that a diet containing condensed tannins with and without polyethylene glycol (PEG) has on lamb growth and meat quality. Twenty-three male Comisana lambs were introduced to the three experimental diets between 45 and 50 d of age. Eight were given a diet containing 56% of Ceratonia siliqua (carob) pulp (tannin group), another eight received the same diet with a supplement of 40 g of PEG for each kilogram of diet (PEG group), and the remaining seven lambs were given a conventional maize-based diet (maize group). Voluntary feed intake and live weights were measured until slaughter at 105 d of age, and digestibility measurements were undertaken toward the end of the feeding trial. Carcass yield, meat quality characteristics, and a taste panel evaluation were conducted. The tannin-based diet contained 2.5% condensed tannins (DM basis), and lambs given this diet had lower growth rates and poorer feed efficiencies (P < .01) compared with the other treatment groups. Daily gain was similar between the maize and PEG lambs, although the efficiency of feed conversion was highest in the maize group. The digestibility of DM, N, and fiber was reduced (P < .05) by the condensed tannins. Lambs fed the tannin diet had a lower carcass yield (P < .05) and had less fat (P < .05), and the meat had a higher ultimate pH (P < .01) than those given the PEG or maize diets. Condensed tannins affected meat color, which was lighter (L*) than meat from lambs given the PEG-containing diet (P < .01). Sensory evaluation showed that panelists preferred meat from lambs receiving PEG and maize treatments compared with those receiving the tannin diet, and this could be related to differences in meat ultimate pH and carcass fatness. These results show that condensed tannins from carob pulp are very detrimental to feed digestibility and lamb performance. Inclusion of 40 g of PEG/kg diet eliminated the effects of condensed tannins so that lamb performance and meat quality were similar to lambs given a maize-based diet.


Assuntos
Ração Animal , Carne/normas , Polietilenoglicóis/farmacologia , Polissacarídeos/metabolismo , Ovinos/crescimento & desenvolvimento , Taninos/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Digestão , Galactanos , Masculino , Mananas , Gomas Vegetais , Rúmen/metabolismo , Taninos/metabolismo
12.
Meat Sci ; 50(3): 355-63, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22061154

RESUMO

Sixteen male Comisana lambs were divided into two groups of eight at age 45 days. One group received a commercial pelleted diet (control) and the other group (carob) received a diet in which 20% carob pulp was used in partial replacement of barley. The animals were slaughtered at 100 days. No significant differences were observed for live weight, although the carob group ate 14% more dry matter, showing a higher conversion index (2.68 and 3.22kg dry matter per kg weight gain respectively for control and carob). The dressing percentage was higher (p < 0.05) for the control group; however, the carcasses showed no differences in the European classification system. Lightness (lean colour) was the only meat quality parameter (p < 0.05) affected by diet treatment: the carob group lambs had a higher L (∗) value. This could not be attributed to ultimate pH, which was not significantly different between the two groups. In triangle tests, sensory panelists were unable to distinguish one diet treatment from the other. Instrumental tenderness was also unaffected by diet treatment.

13.
Clin Ter ; 141(9 Pt 2): 49-54, 1992 Sep.
Artigo em Italiano | MEDLINE | ID: mdl-1468198

RESUMO

The aim of this study was to evaluate the variations of thyroid autoantibodies titre in a group of 15 patients affected with "Graves' disease" (G. D.) during the treatment with antithyroid drug (ATD) and "high dose intravenous immunoglobulin" (IVIG) for "Graves' ophthalmopathy". Before the starting of treatment thyroglobulin antibodies (TgAb) were positive in 10/15 patients, microsomal antibodies (MAb) were positive in 13/15 patients and TRAb were positive in 5/9 patients. At the end of treatment TgAb titre was decreased or negative in 7/10 patients, MAb titre was decreased or negative in 7/13 patients, TRAb titre was diminished or negativized in 5/5 patients. Anti-nuclear antibodies (ANA) and anti-smooth muscle antibodies (ASMA) were positive in 3/15 and 3/15 patients before the treatment and in all these we observed a reduction or negativization of circulating titre during IVIG treatment. Anti-extractable nuclear antigen (ENA)m anti-mitochondrial antibodies (AMA) and rheumatoid factors were negative in all the patients. Also in the 3 patients not treated with ATD we have observed a reduction or a negativization of circulating thyroid autoantibodies. In conclusion these data suggest that the reduction of thyroid and non organ specific autoantibodies might be due to a stable immunosuppressive action of IVIG treatment in patients with Graves' disease.


Assuntos
Autoanticorpos/sangue , Doença de Graves/imunologia , Doença de Graves/terapia , Imunoglobulinas Intravenosas/uso terapêutico , Glândula Tireoide/imunologia , Humanos , Microssomos/imunologia , Especificidade de Órgãos/imunologia
14.
Meat Sci ; 96(4): 1489-93, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24440744

RESUMO

This study investigated the effect of replacing cereal concentrates with high levels of dried citrus pulp in the diet on lamb meat oxidative stability. Over 56 days, lambs were fed a barley-based concentrate (Control) or concentrates in which 24% and 35% dried citrus pulp were included to partially replace barley (Citrus 24% and Citrus 35%, respectively). Meat was aged under vacuum for 4 days and subsequently stored aerobically at 4 °C. The Control diet increased the redness, yellowness and saturation of meat after blooming (P<0.01). Regardless of the level of supplementation, dietary dried citrus pulp strongly reduced meat lipid oxidation over 6 days of aerobic storage (P<0.001), while colour parameters did not change noticeably over storage and their variation rate was not affected by the diet. In conclusion, replacing cereals with dried citrus pulp in concentrate-based diets might represent a feasible strategy to naturally improve meat oxidative stability and to promote the exploitation of this by-product.


Assuntos
Citrus , Suplementos Nutricionais , Conservação de Alimentos , Frutas , Peroxidação de Lipídeos , Carne/análise , Preparações de Plantas , Ração Animal , Animais , Cor , Armazenamento de Alimentos , Humanos , Carneiro Doméstico
15.
Animal ; 8(1): 51-7, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24168780

RESUMO

Sixteen lambs were divided into two groups and fed two different diets. Eight lambs were stall-fed with a concentrate-based diet (C), and the remaining eight lambs were allowed to graze on Lolium perenne (G). The antioxidant status was measured in the liver and plasma samples before and after solid-phase extraction (SPE) to probe the antioxidant effects that grass phenolic compounds may have conferred onto the animal tissues. The liver and plasma samples from grass-fed lambs displayed a greater antioxidant capacity than the tissues from C lamb group, but only if samples had not been passed through SPE cartridges. Finally, the feed and animal tissues, which had been purified by SPE, were analysed by liquid chromatography combined with mass spectrometry (LC���MS) to identify phenolic compounds present in L. perenne and to evaluate the results from the antioxidant assays. It would appear that the improvement of the antioxidant capacity of lamb liver and plasma from lambs fed ryegrass was not related to the direct transfer of phenolic compounds from grass to the animal tissues.


Assuntos
Antioxidantes/farmacologia , Fígado/metabolismo , Lolium/química , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Ovinos/metabolismo , Animais , Cromatografia Líquida , Fígado/efeitos dos fármacos , Espectrometria de Massas , Ovinos/sangue , Extração em Fase Sólida
16.
Meat Sci ; 95(2): 212-8, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23747613

RESUMO

Over 89 days, 10 lambs (S) were fed concentrates and hay in stall, while 9 lambs (P) grazed at pasture. Two groups of 9 animals grazed at pasture until switching to a concentrate-based diet for 14 or 37 days before slaughter (P-S14 and P-S37). The fat content of longissimus dorsi muscle (LM) increased with increasing duration of concentrate feeding (P=0.05). As a consequence, the concentration of polyunsaturated fatty acids (PUFA) and of the highly peroxidisable (HP) PUFA in the polar lipids was similar between treatments. Lipid oxidation in fresh LM over 8 days of storage was affected by the diet (P<0.0005) with the P-S37 and P treatments producing, respectively, the highest and the lowest TBARS values. The P treatment reduced TBARS in cooked minced LM over 2 days of storage and no difference was found between the P-S14, P-S37 and S treatments. Colour stability of fresh LM was not noticeably affected by the dietary treatment.


Assuntos
Ração Animal/análise , Metabolismo dos Lipídeos , Carne/análise , Estresse Oxidativo , Matadouros , Animais , Cor , Culinária , Ácidos Graxos Insaturados/metabolismo , Armazenamento de Alimentos , Masculino , Músculos Paraespinais/metabolismo , Carneiro Doméstico , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
17.
Animal ; 7(9): 1559-66, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23597321

RESUMO

Multielemental stable isotope ratio (SIR) analysis was used in lamb plasma, erythrocytes and muscle to detect the switch from a pasture- to a concentrate-based diet, with the aim of verifying the possibility to trace the change of feeding in animal tissues. During 89 days of experimental feeding, lambs were subjected to four dietary treatments: pasture (P), pasture followed by concentrate in the stall for either 14 days (P-S14) or 37 days (P-S37) or concentrate in the stall (S). Pasture and concentrate diets comprised C3 plants only and had different values of 13C/12C, 18O/16O, 2H/1H and 34S/32S ratios. Muscle 13C/12C and 34S/32S and plasma 13C/12C and 18O/16O ratios in P, P-S14 and P-S37 lambs were significantly different. A multivariate analytical approach revealed that 13C/12C and 18O/16O ratios in plasma were the most powerful variables for the discrimination among the dietary treatments.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Dieta , Músculo Esquelético/química , Ovinos/sangue , Análise de Variância , Animais , Isótopos de Carbono/sangue , Análise Discriminante , Itália , Espectrometria de Massas/veterinária , Análise Multivariada , Isótopos de Oxigênio/sangue , Isótopos de Enxofre/sangue , Trítio/sangue
18.
Meat Sci ; 92(1): 30-5, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22542075

RESUMO

Over 72 days, 33 lambs were fed: concentrates in stall (S), grass at pasture for 8 hours (8 h), or grass at pasture for 4 hours in the afternoon (4h-PM). The 4h-PM treatment did not affect the carcass yield compared to the 8h treatment. Meat colour development after blooming was unaffected by the treatments. The 4 h-PM treatment increased the proportion of polyunsaturated fatty acids (PUFA; P<0.0005) and of the highly peroxidizable fatty acids (HP-PUFA; P<0.001) in meat compared to the 8h treatment. The S treatment increased lipid oxidation (higher TBARS values) and impaired colour stability (higher H* values) of meat over storage compared to the 8h and 4 h-PM treatments (P<0.0005 and P=0.003, respectively). No difference in meat oxidative stability was found between the 8h and the 4h-PM treatments. In conclusion, growing lambs can tolerate a restriction of grazing duration without detrimental effects on performances and meat oxidative stability.


Assuntos
Ração Animal , Criação de Animais Domésticos/métodos , Cor , Gorduras na Dieta/metabolismo , Ácidos Graxos Insaturados/metabolismo , Peroxidação de Lipídeos , Carne/análise , Animais , Dieta , Poaceae , Ovinos , Tiobarbitúricos/metabolismo
19.
J Anim Sci ; 89(11): 3759-68, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21705637

RESUMO

The present study was designed to assess the balance between antioxidant and prooxidant components and the oxidative stability of beef from cattle fed exclusively grazed pasture (PAS) or a barley-based concentrate offered indoors (CONC) for 11 mo, or fed grass silage indoors for a 5-mo winter period, followed for the remaining 6-mo summer period by grazed pasture (SiP) or by grazed pasture plus concentrate at 50% of the dietary DM (SiPC). Muscle prooxidant and antioxidant components were determined by measuring fatty acids and α-tocopherol concentration of LM, respectively. Lipid oxidation and color stability were monitored in ground LM, packaged in a high-oxygen modified atmosphere, over 11 d of refrigerated storage. Vitamin E concentration decreased (P < 0.0005) with an increasing proportion of concentrate in the diet (2.59, 2.45, 1.76, and 1.15 µg/g for PAS, SiP, SiPC, and CONC, respectively). A greater proportion of PUFA was found in LM from cattle in the PAS, SiP, and SiPC groups compared with animals in the CONC group (9.62, 11.04, 8.96, and 6.94%, respectively; P < 0.0005). A greater concentration of highly peroxidizable PUFA was found in LM from heifers in the PAS, SiP, and SiPC groups compared with those in the CONC group (0.84, 0.85, 0.87, and 0.65 mg/g of muscle, respectively; P = 0.02). Dietary treatment affected lipid oxidation (P < 0.0005), with greater 2-thiobarbituric acid reactive substance values in beef from heifers in the SiPC group than in beef from those in the PAS, SiP, and CONC groups. Dietary treatment affected myoglobin oxidation (P = 0.002) during storage, with greater metmyoglobin accumulation in beef from animals receiving concentrate (CONC and SiPC treatments) than in beef from cattle in the PAS and SiP groups. Consequently, feeding concentrate impaired meat color stability over the storage duration, with greater H* (hue angle) values (P < 0.0005) in meat from heifers in the SiPC and CONC groups compared with meat from those in the PAS and SiP groups. The results of the present study confirm a positive effect of grass-based feeding systems on meat color stability compared with concentrate-based dietary strategies. It appears that vitamin E in muscle alone does not explain the resistance of meat to oxidative deterioration because a clear interaction with highly peroxidizable PUFA exists.


Assuntos
Criação de Animais Domésticos/métodos , Bovinos/metabolismo , Dieta/veterinária , Carne/normas , Músculo Esquelético/metabolismo , alfa-Tocoferol/análise , Ração Animal , Animais , Ácidos Graxos Insaturados/sangue , Feminino , Metamioglobina/metabolismo , Poaceae , Distribuição Aleatória , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
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