Objetivou-se avaliar a influência da condição sexual sobre o desempenho, características de carcaça e qualidade da carne de bovinos Angus x Nelore, terminados em confinamento. Foram utilizados 176 bovinos, com idade média de 20 meses, pertencentes ao Programa Brasileiro de Carne Angus Certificada, divididos em quatro condições sexuais (CS): 32 machos não castrados (NC), 48 machos castrados cirurgicamente (CC), 48 machos imunocastrados (IM) e 48 fêmeas (F). Para a imunocastração dos bovinos, foram utilizadas três doses de uma vacina anti-GnRH. Os animais foram confinados durante 190 dias, com a mesma dieta, composta de 80% de concentrado e 20% de volumoso na matéria seca. Ao final deste período, os bovinos foram abatidos. Durante o abate, foi calculado o rendimento de carcaça quente (RCQ) e avaliado o pH. Na desossa, foi avaliada no m. Longissimus a área de olho de lombo (AOL), espessura de gordura subcutânea (EGS) entre a 12ª e 13ª costelas, marmorização, cor e pH. Foram coletadas amostras de 2,54 cm de espessura do m. Longissimus, embaladas a vácuo e maturadas por zero (sem maturação), 7 e 14 dias, a 2°C para análises de maciez objetiva (FC) e subjetiva, perdas por cocção (PPC), teor de extrato etéreo (EE) e perfil de ácidos graxos. Utilizou-se o procedimento MIXED do programa SAS® e a significância foi declarada quando P ≤ 0,05. Os machos NC apresentaram maior peso vivo final, ganho de peso médio diário, AOL e maiores valores de pH em relação às demais condições sexuais (P < 0,01). Para PCQ, os machos NC e IM apresentaram valores mais elevados do que machos CC e fêmeas (P < 0,01). Por outro lado, as fêmeas apresentaram maior EGS em relação às demais categorias (P < 0,01). O escore de marmorização foi maior na carne das fêmeas e machos CC do que dos machos NC e IM (P < 0,01), no entanto, a carne dos machos CC apresentou maior escore de gordura intramuscular Prime do que a carne das fêmeas. Para RCQ não houve diferença entre as CS. Houve maior PPC na carne dos machos CC (P < 0,01) e a carne das fêmeas apresentou maior teor de EE em relação às demais categorias (P = 0,0248). Houve interação entre CS e dias de maturação para os valores de FC (P = 0,0002) e para os valores de L* (P = 0,0118) e b* (P = 0,0113). A maturação influenciou a cor da carne, em função da CS e ambas favoreceram a maciez da carne de todas as CS avaliadas, especialmente de machos NC e fêmeas. A CS influenciou todos os atributos avaliados na análise sensorial (P < 0,05). A carne de fêmeas e animais castrados, sejam imunocastrados ou castrados por método cirúrgico, apresentaram melhor aceitação pelos consumidores na análise. Adicionalmente, a carne das fêmeas apresentou PAG mais favorável à saúde humana, enquanto a carne dos machos NC apresentou um perfil de AG menos saudável (P < 0,05). A imunocastração pode ser uma alternativa à castração cirúrgica, pois os resultados associados à melhoria na qualidade da carne de bovinos cruzados Angus x Nelore, são similares aos encontrados para os machos CC. Entretanto, vale ressaltar que os bovinos CC produzem carne com maior deposição de gordura intramuscular do que os IM e que os custos financeiros da imunocastração devem ser levados em consideração para a produção da carne. Ainda, as diferenças no perfil de ácidos graxos podem indicar que a CS pode impactar o valor nutricional da carne em termos de saúde humana. / The goal of this work was to evaluate sexual condition effects on performance, carcass traits, and meat quality of a feedlot Angus x Nellore cattle. Were used 176 cattle, 20 months of age, from the Brazilian Certified Angus Beef Program, assigned into four sexual conditions: 32 bulls, 48 steers, 48 immunocastrated, and 48 heifers. The immunocastrated were obtained by vaccinating three times with anti-GnRH vaccine. Animals were fed ad libitum with a highgrain diet containing 80% concentrate. At the end of the experimental period (190 days) the animals were harvested. At the slaughter were collected data related to the carcass yield and pH values. After slaughter, were evaluated in Longissimus muscle, the rib eye area, and subcutaneous fat thickness between the 12th and 13th ribs, marbling score, color, and pH. Vacuum packaged steaks (2.54 cm thick) from the Longissimus muscle were collected, aging for zero, 7, and 14 days at 2°C and stored at -18°C until analysis of meat quality. Statistical analyzes were performed using the proc MIXED SAS® program (version 9.2). Bulls presented increased final body weight, average daily gain, rib eye area, and pH values when compared with the other sexual conditions (P < 0.01). For hot carcass weight, bulls and immunocastrated had higher values compared to steers and heifers (P < 0.01). Interestingly, heifers presented higher subcutaneous fat thickness compared to the other categories (P < 0.01). Heifers and steers presented increased intramuscular fat scores compared to the bulls and immunocastrated; however, beef from steers presented higher marbling Prime scores when compared with beef from heifers. Beef from steers had higher cooking loss (P < 0.01) and beef from heifers presented higher ether extract content when compared with other sexual conditions (P = 0.0248). There was interaction between sexual condition and aging time for Warner Bratzler Shear Force (WBSF) values (P = 0.0002), L* (P = 0.0118) and b* (P = 0.0113) values. The period of aging affected beef color, depending of the sexual condition. In addition, all cattle categories evaluated had beef tenderness improved by the aging process and sexual condition, especially beef from bulls and heifers. Sexual condition had main influence in all beef sensorial attributes (P < 0.05). Beef from heifers, steers, and immunocastrated cattle had better consumer´s acceptability in sensory analysis then the beef from bulls. Additionally, beef from heifers presented favorable fatty acid profile for human healthy, while beef from bulls had an unfavorable fatty acid profile (P < 0.05). In conclusion, immunocastration can be an alternative to surgical castration, since it improves meat quality with results like those for Angus x Nellore steers. However, it is important to highlight that the steers produce high intramuscular fat deposition then the immunocastrated, and the cost of immunocastration should be taken into consideration for the beef cattle production. Additionally, the difference on fatty acid profile can indicate that the sexual condition can impact the nutrition values of the meat.

Vinte e oito bovinos Brangus foram usados para se determinar o efeito da suplementação de cobre e selênio no desempenho, características de carcaça, composição de ácidos graxos no músculo Longissimus dorsi (LD) e na concentração de colesterol sérico e no músculo LD . Os tratamentos foram : 1) C(Controle) - sem a suplementação de cobre e selênio; 2) Se - 2 mg Se/kg de matéria seca na forma de selenito de sódio; 3) Cu- 40 mg Cu/kg de matéria seca na forma de sulfato de cobre; 4) Se/Cu- 2 mg Se/kg de matéria seca na forma de selenito de sódio e 40 mg Cu/kg de matéria seca na forma de sulfato de cobre. O ganho de peso diário aumentou com a suplementação de selênio (P<0,05). A eficiência alimentar foi melhor (P<0,05) nos tratamentos selênio, cobre e selênio/cobre, em relação ao controle. A ingestão de matéria seca não foi alterada pelos tratamentos (P>0,05). A espessura de gordura e composição de ácidos graxos do músculo LD não foram influenciados pelos tratamentos (P>0,05). A concentração sérica de colesterol não foi influenciada pelos tratamentos (P>0,05), entretanto, a concentração de colesterol no LD foi menor nos bovinos suplementados com cobre e selênio (P < 0.05). A glutationa peroxidase e GSSG aumentaram (P<0,05) com a suplementação de cobre , selênio ou selênio/cobre (P <0,05). / Twenty eight Brangus steers were used to determine the effects of copper (Cu) and selenium (Se) supplementation on performance, carcass characteristics, Longissimus dorsi muscle fatty acid composition and serum and Longissimus dorsi muscle cholesterol concentrations. Treatments were: 1) control - no supplemental Cu and Se; 2) Se - 2 mg Se/kg DM as sodium selenite; 3) Cu - 40 mg Cu/kg DM as copper sulfate; 4) Se/Cu - 2 mg Se/kg DM as sodium selenite and 40 mg Cu/kg DM as copper sulfate. Daily weight gain increased with selenium supplementation (P<0,05). Feed efficiency was better in selenium, copper and selenium/copper treatments than in the control group. Dry matter intake was not affected by treatments (P>0.05). Backfat and Longissimus dorsi fatty acid concentrations were not affected by treatments (P > 0.05). Serum cholesterol concentration was not affected by treatments (P>0.05), however, Longissimus dorsi cholesterol concentrations were lower in steers supplemented with Cu and Se (P<0.05). GSSG and GSH Px increased (P<0.05) with Cu, Se and Se/Cu supplementation.

Objetivou-se avaliar a influência da condição sexual sobre o desempenho, características de carcaça e qualidade da carne de bovinos Angus x Nelore, terminados em confinamento. Foram utilizados 176 bovinos, com idade média de 20 meses, pertencentes ao Programa Brasileiro de Carne Angus Certificada, divididos em quatro condições sexuais (CS): 32 machos não castrados (NC), 48 machos castrados cirurgicamente (CC), 48 machos imunocastrados (IM) e 48 fêmeas (F). Para a imunocastração dos bovinos, foram utilizadas três doses de uma vacina anti-GnRH. Os animais foram confinados durante 190 dias, com a mesma dieta, composta de 80% de concentrado e 20% de volumoso na matéria seca. Ao final deste período, os bovinos foram abatidos. Durante o abate, foi calculado o rendimento de carcaça quente (RCQ) e avaliado o pH. Na desossa, foi avaliada no m. Longissimus a área de olho de lombo (AOL), espessura de gordura subcutânea (EGS) entre a 12ª e 13ª costelas, marmorização, cor e pH. Foram coletadas amostras de 2,54 cm de espessura do m. Longissimus, embaladas a vácuo e maturadas por zero (sem maturação), 7 e 14 dias, a 2°C para análises de maciez objetiva (FC) e subjetiva, perdas por cocção (PPC), teor de extrato etéreo (EE) e perfil de ácidos graxos. Utilizou-se o procedimento MIXED do programa SAS® e a significância foi declarada quando P &le; 0,05. Os machos NC apresentaram maior peso vivo final, ganho de peso médio diário, AOL e maiores valores de pH em relação às demais condições sexuais (P &lt; 0,01). Para PCQ, os machos NC e IM apresentaram valores mais elevados do que machos CC e fêmeas (P &lt; 0,01). Por outro lado, as fêmeas apresentaram maior EGS em relação às demais categorias (P &lt; 0,01). O escore de marmorização foi maior na carne das fêmeas e machos CC do que dos machos NC e IM (P &lt; 0,01), no entanto, a carne dos machos CC apresentou maior escore de gordura intramuscular Prime do que a carne das fêmeas. Para RCQ não houve diferença entre as CS. Houve maior PPC na carne dos machos CC (P &lt; 0,01) e a carne das fêmeas apresentou maior teor de EE em relação às demais categorias (P = 0,0248). Houve interação entre CS e dias de maturação para os valores de FC (P = 0,0002) e para os valores de L* (P = 0,0118) e b* (P = 0,0113). A maturação influenciou a cor da carne, em função da CS e ambas favoreceram a maciez da carne de todas as CS avaliadas, especialmente de machos NC e fêmeas. A CS influenciou todos os atributos avaliados na análise sensorial (P &lt; 0,05). A carne de fêmeas e animais castrados, sejam imunocastrados ou castrados por método cirúrgico, apresentaram melhor aceitação pelos consumidores na análise. Adicionalmente, a carne das fêmeas apresentou PAG mais favorável à saúde humana, enquanto a carne dos machos NC apresentou um perfil de AG menos saudável (P &lt; 0,05). A imunocastração pode ser uma alternativa à castração cirúrgica, pois os resultados associados à melhoria na qualidade da carne de bovinos cruzados Angus x Nelore, são similares aos encontrados para os machos CC. Entretanto, vale ressaltar que os bovinos CC produzem carne com maior deposição de gordura intramuscular do que os IM e que os custos financeiros da imunocastração devem ser levados em consideração para a produção da carne. Ainda, as diferenças no perfil de ácidos graxos podem indicar que a CS pode impactar o valor nutricional da carne em termos de saúde humana. / The goal of this work was to evaluate sexual condition effects on performance, carcass traits, and meat quality of a feedlot Angus x Nellore cattle. Were used 176 cattle, 20 months of age, from the Brazilian Certified Angus Beef Program, assigned into four sexual conditions: 32 bulls, 48 steers, 48 immunocastrated, and 48 heifers. The immunocastrated were obtained by vaccinating three times with anti-GnRH vaccine. Animals were fed ad libitum with a highgrain diet containing 80% concentrate. At the end of the experimental period (190 days) the animals were harvested. At the slaughter were collected data related to the carcass yield and pH values. After slaughter, were evaluated in Longissimus muscle, the rib eye area, and subcutaneous fat thickness between the 12th and 13th ribs, marbling score, color, and pH. Vacuum packaged steaks (2.54 cm thick) from the Longissimus muscle were collected, aging for zero, 7, and 14 days at 2°C and stored at -18°C until analysis of meat quality. Statistical analyzes were performed using the proc MIXED SAS® program (version 9.2). Bulls presented increased final body weight, average daily gain, rib eye area, and pH values when compared with the other sexual conditions (P &lt; 0.01). For hot carcass weight, bulls and immunocastrated had higher values compared to steers and heifers (P &lt; 0.01). Interestingly, heifers presented higher subcutaneous fat thickness compared to the other categories (P &lt; 0.01). Heifers and steers presented increased intramuscular fat scores compared to the bulls and immunocastrated; however, beef from steers presented higher marbling Prime scores when compared with beef from heifers. Beef from steers had higher cooking loss (P &lt; 0.01) and beef from heifers presented higher ether extract content when compared with other sexual conditions (P = 0.0248). There was interaction between sexual condition and aging time for Warner Bratzler Shear Force (WBSF) values (P = 0.0002), L* (P = 0.0118) and b* (P = 0.0113) values. The period of aging affected beef color, depending of the sexual condition. In addition, all cattle categories evaluated had beef tenderness improved by the aging process and sexual condition, especially beef from bulls and heifers. Sexual condition had main influence in all beef sensorial attributes (P &lt; 0.05). Beef from heifers, steers, and immunocastrated cattle had better consumer´s acceptability in sensory analysis then the beef from bulls. Additionally, beef from heifers presented favorable fatty acid profile for human healthy, while beef from bulls had an unfavorable fatty acid profile (P &lt; 0.05). In conclusion, immunocastration can be an alternative to surgical castration, since it improves meat quality with results like those for Angus x Nellore steers. However, it is important to highlight that the steers produce high intramuscular fat deposition then the immunocastrated, and the cost of immunocastration should be taken into consideration for the beef cattle production. Additionally, the difference on fatty acid profile can indicate that the sexual condition can impact the nutrition values of the meat.

No description available.

N-Acylethanolamines (NAEs) are bioactive lipids derived from the hydrolysis of the membrane phospholipid N-acylphosphatidylethanolamine (NAPE). In animal systems this reaction is part of the “endocannabinoid” signaling pathway, which regulates a variety of physiological processes. The signaling function of NAE is terminated by fatty acid amide hydrolase (FAAH), which hydrolyzes NAE to ethanolamine and free fatty acid. Our previous work in Arabidopsis thaliana showed that overexpression of AtFAAH (At5g64440) lowered endogenous levels of NAEs in seeds, consistent with its role in NAE signal termination. Reduced NAE levels were accompanied by an accelerated growth phenotype, increased sensitivity to abscisic acid (ABA), enhanced susceptibility to bacterial pathogens, and early flowering. Here we investigated the nature of the early flowering phenotype of AtFAAH overexpression. AtFAAH overexpressors flowered several days earlier than wild type and AtFAAH knockouts under both non-inductive short day (SD) and inductive long day (LD) conditions. Microarray analysis revealed that the FLOWERING LOCUS T (FT) gene, which plays a major role in regulating flowering time, and one target MADS box transcription factor, SEPATALLA3 (SEP3), were elevated in AtFAAH overexpressors. Furthermore, AtFAAH overexpressors, with the early flowering phenotype had lower endogenous NAE levels in leaves compared to wild type prior to flowering. Exogenous application of NAE 12:0, which was reduced by up to 30% in AtFAAH overexpressors, delayed the onset of flowering in wild type plants. We conclude that the early flowering phenotype of AtFAAH overexpressors is, in part, explained by elevated FT gene expression resulting from the enhanced NAE hydrolase activity of AtFAAH, suggesting that NAE metabolism may participate in floral signaling pathways.

Given the dramatic rise in obesity and the diseases linked with it, it is becoming increasingly important to understand the mechanisms that underlie the body's ability to recognize fat. The chemoreception of dietary fat in the oral cavity has largely been attributed to activation of the somatosensory system that relays the textural properties of fat. However, the ability of fatty acids, which are believed to represent the proximate stimulus for fat taste, to activate trigeminal ganglionic neurons has remained unexplored. In general, my research has provided the first evidence of fatty acids activating the somatosensory system by increasing the intracellular calcium concentration and generating receptor potentials. Other experiments were focused on identifying fatty acids-responsive pathways in acute isolated trigeminal neurons involved with fat somatosensory perception. My results revealed that fatty acids-activated pathways involved the release of intracellular calcium stores in subpopulations of trigeminal neurons. By using pseudorabies virus as a "live-cell" tracer, a subpopulation of lingual-innervated trigeminal neurons was labeled. Quantitative real-time polymerase chain reaction on individual neurons showed several transient receptor potential channel markers were expressed in these labeled neurons, which indicated the identification of lingual-innervated neurons was successful. This technique helped resolve the problem of trigeminal neurons being a mixed population of cells, and confirmed the role of the release of intracellular calcium stores in fatty acid-activated pathways. Using patch clamp recording, I discovered that the linoleic acid activated signaling pathway involved the activation of G protein and phospholipase C. I further began to characterize the downstream conductance that is activated by linoleic acid in rat trigeminal neurons. Using perforated patch clamp recording, I have recorded linoleic acid-induced currents that exhibited many of the properties of transient receptor potential-like channels, suggesting that this "cellular sensor" is probably playing an important role in the somatosensory perception of fat. Taken together, this dissertation research has revealed the ability of fatty acids to act as effective tactile stimuli and identified several elements of the fatty acids-activated signaling pathway involved in the somatosensory perception of fat.

Metabolic cycles are a fundamental element of cellular and organismal function. Among the most critical in higher organisms is the Cori Cycle, the systemic cycling between lactate and glucose. Here, skeletal muscle-specific Mitochondrial Pyruvate Carrier (MPC) deletion in mice increased muscle glucose uptake but diverted pyruvate into the circulation as lactate, driving increased Cori Cycling and energy expenditure. Loss of muscle MPC activity evoked adaptive glutaminolysis, increased fatty acid oxidation, and resulted in a striking resistance to gains in fat mass with age with perfect sparing of muscle mass and strength. Furthermore, chronic and acute muscle MPC deletion accelerated fat mass loss on a normal diet after high fat diet-induced obesity. Our results illuminate the role of the skeletal muscle MPC as a central node for whole-body carbohydrate, fat, and amino acid metabolism. They highlight the potential utility of decreasing muscle pyruvate oxidation to ameliorate obesity and type 2 diabetes.

The effects of starter cultures on short- to medium-chain free fatty acid contents am sensory attributes of different batches of summer sausages were determined. The summer sausages were from range ram mutton, and formulated after grinding to contain 23% fat. Commercial starter cultures from different sources, including Micrococcus varians or Micrococcus species and Lactobacillus plantarum, commercial microbial lipase, an indigenous Micrococcus isolate or encapsulated lactic acid were used to prepare the summer sausages. Three batches were made, each batch receiving six different treatments. Three consumer panels evaluated the sausages for acceptability and a trained screened panel evaluated the products using the flavor profile test. Encapsulated lactic acid treatment significantly improved the sensory acceptability of the sausages. Presence of mutton flavor was not detected in indigenous Micrococcus isolate and L. plantarum treatment. Gas chromatography was used to quantify all short- to medium-chain fatty acids from the sausages. Common fatty acids, C6 through C12, were identified by retention data. Increased C6 and C8 levels due to addition of lipase were associated with increase in mutton and rancidity flavors of the product. The relationships among the level of major fatty acids and the sensory parameters were mostly negative.

Recent investigations suggest that reducing stearoyl CoA desaturase (SCD) 1 expression confers protection against obesity and insulin resistance, whereas others show that increasing SCD1 expression protects cells from lipotoxicity. The overall aim of this thesis was to establish the role of SCD1 expression in fatty acid metabolism and insulin stimulated glucose disposal in skeletal muscle. In vitro and in vivo studies were conducted to investigate the relationship between fatty acid subtype, SCD1 expression and fuel metabolism. The role of fatty acid subtype on fatty acid metabolite accumulation and insulin resistance was initially examined in rats. Rats were provided with a low fat diet or a high fat diet consisting of predominantly saturated (SAT) or polyunsaturated fatty acids (PUFA). Rats fed a SAT diet were insulin resistant and had increased skeletal muscle diacylglycerol content whereas rats fed a PUFA diet retained insulin sensitivity and accumulated triacylglycerol rather than diacylglycerol. Interestingly, SCD1 mRNA and protein content were elevated in SAT rats compared with PUFA fed and control fed rats, indicating a possible involvement of SCD1 in the aetiology of insulin resistance. Subsequently, SCD1 expression was examined in the skeletal muscle of various rodent models of genetic and diet-induced obesity. SCD1 content was consistently upregulated in the skeletal muscle of obese rodents. To determine whether SCD1 contributes to or protects from fatty-acid induced insulin resistance, SCD1 levels were transiently altered in L6 skeletal muscle myotubes. Short interfering (si) RNA was used to decrease SCD1 content and a pcDNA3.1/HygromSCD1 vector was introduced to increase SCD1 content. Reducing SCD1 protein resulted in marked esterification of exogenous fatty acids into diacylglycerol and ceramide. Insulin-stimulated Akt (acute transforming retrovirus thymoma) phosphorylation and 2-deoxyglucose uptake were reduced with SCD1 siRNA. Exposure of L6 myotubes to palmitate abolished insulin-stimulated glucose uptake in both control and SCD1 siRNA myotubes. Transient overexpression of SCD1 resulted in triacylglycerol esterification but attenuated ceramide and diacylglycerol accumulation and protected myotubes from fatty acid-induced insulin resistance. Further, these changes were associated with reduced phosphorylation of c-Jun Amino-Terminal Kinase (JNK) and the inhibitor of IêB kinase (IKK), both of which impair insulin signalling. These studies indicated that SCD1 protects from cellular toxicity in L6 myotubes by preventing excessive accumulation of bioactive lipid metabolites. Collectively, these experiments indicate that increasing SCD1 expression may be a protective mechanism designed to prevent insulin resistance in obese phenotypes.

No description available.