Influências genéticas nas características da carcaça e carne em bovinos

Tese de Doutoramento em Ciências Veterinárias - Especialidade de Produção Animal

Musculosidade e composição da perna de ovinos de diferentes genótipos e idades ao abate

Foram avaliadas as características morfológicas da carcaça, musculosidade e composição tecidual da perna de cordeiros criados em regime de pasto, provenientes de ovelhas Romney, acasaladas com três raças paternas (Romney, East Friesian x (Finn x Texel) e Finn x Poll Dorset). Aos 150 e 300 dias de idade, os cordeiros foram abatidos em dois lotes, cada um com 15 animais de cada raça paterna, num total de 90 animais. O grupo oriundo de animais East Friesian x (Finn x Texel) apresentou maior quantidade de músculo na perna (1.975 g) e, em comparação ao grupo Romney, semelhante musculosidade da perna (0,45) e maior relação músculo:osso (7x6,69). A musculosidade da perna nos animais descendentes de Finn x Poll Dorset foi menor (0,44), quando comparada à dos demais grupos. Cordeiros abatidos mais tardiamente apresentaram carcaças mais longas e magras, provavelmente pelas condições adversas do verão e do outono, em que são típicas a menor taxa de crescimento e a qualidade inferior de forragem. O genótipo e a idade de abate influem nas características morfológicas da carcaça, no índice de musculosidade e de composição tecidual da perna dos cordeiros.

Características de qualidade da carne de ovinos de diferentes genótipos e idades ao abate

Cordeiros criados em regime de pasto, provenientes de ovelhas Romney acasaladas com três raças paternas (Romney, East Friesian x (Finn x Texel) e Finn x Poll Dorset), foram avaliados quanto às características de qualidade da carne. Os cordeiros foram abatidos aos 150 e 300 dias de idade, cada lote com 15 animais de cada raça paterna, totalizando 90 animais. A carne dos cordeiros Romney foi mais macia que a dos demais genótipos. O pH final do músculo Semimembranosus dos cordeiros abatidos mais precocemente foi superior (5,61) ao dos abatidos mais tardiamente (5,58), entretanto estes últimos apresentaram carne com menor maciez (11,16 kg) que os abatidos aos 150 dias de idade (7,45 kg). Com relação à cor, a luminosidade da carne de cordeiros abatidos aos 150 dias foi maior (38,20) que a dos abatidos mais tardiamente (36,80), mas não foi afetada pelo genótipo. Concluiu-se que o genótipo e a idade de abate influíram na produção e qualidade da carne ovina.

Perfil lipídico da carne de cordeiros da raça Morada Nova.

Objetivou-se nesse trabalho verificar se a idade ao abate e o uso de suplementação no período pré-desmame altera o perfil lipídico da carne de cordeiros da raça Morada Nova.

Quality control of Toxoplasma gondii in meat packages: Standardization of an ELISA test and its use for detection in rabbit meat cuts

Toxoplasma gondii causes severe disease both to man and livestock and its detection in meat after slaughtering requires PCR or biological tests. Meat packages contain retained exudate that could be used for serology due to its blood content. Similar studies reported false negative assays in those tests. We standardized an anti-T. gondii IgG ELISA in muscle juices from experimentally infected rabbits, with blood content determination by cyanhemoglobin spectrophotometry. IgG titers and immunoblotting profiles were similar in blood, serum or meat juice, after blood content correction. These assays were adequate regardless of the storage time up to 120 days or freeze-thaw cycles, without false negative results. We also found 1.35% (1/74) positive sample in commercial Brazilian rabbit meat cuts, by this assay. The blood content determination shows ELISA of meat juice may be useful for quality control for toxoplasmosis monitoring. (C) 2011 Elsevier Ltd. All rights reserved.

Microbial spoilage and quality of marinated dark, firm, dry meat

Estudi elaborat a partir d’una estada al Royal Veterinary and Agricultural University of Denmark entre els mesos de Març a Juny del 2006. S’ha investigat l’efecte dels envasats amb atmosferes modificades (MAP), així com la marinació amb vi tint, sobre l’evolució de la contaminació bacteriològica de carns fosques, dures i seques (DFD). Les carns DFD es troben a les canals d’animals que, abans del sacrifici, han estat exposades a activitats musculars prolongades o estrès. Les carns DFD impliquen importants pèrdues econòmiques degut a la contaminació bacteriològica i als problemes tecnològics relacionats amb la alta capacitat de retenció d’aigua. A més a més, és crític per la indústria investigar la diversitat de la contaminació bacteriana, identificar les espècies bacterianes i controlar-les. Però és difícil degut a la inhabilitat per detectar algunes bactèries en medis coneguts, les interaccions entre elles, la complexitat dels tipus de contaminació com són aigua, terra, femtes i l’ambient. La Polymerasa chain reaction- Denaturating Electrophoresis Gel (PCR-DGEE ) pot sobrepassar aquests problemes reflectint la diversitat microbial i les espècies bacterianes. Els resultants han indicat que la varietat bacteriana de la carn incrementava amb els dies d’envasat independentment del mètode d’envasat, però decreixia significativament amb el tractament de marinació amb vi tint. La DGEE ha mostrat diferències en les espècies trobades, indicant canvis en la contaminació bacteriana i les seves característiques en la carn DFD sota els diferents tractaments. Tot i que la marinació és una bona alternativa i solució a la comercialització de carn DFD , estudis de seqüenciació són necessaris per identificar les diferents tipus de bactèries.

Quality assurance mechanisms in agrifood: The case of the Spanish fresh meat sector

The largest fresh meat brand names in Spain are analyzed here to studyhow quality is signaled in agribusiness and how the underlying quality-assurance organizations work. Results show, first, that organizationalform varies according to the specialization of the brand name.Publicly-controlled brand names are grounded on market contracting withindividual producers, providing stronger incentives. In contrast,private brands rely more on hierarchy, taking advantage of itssuperiority in solving specific coordination problems. Second, theseemingly redundant coexistence of several quality indicators for agiven product is explained in efficiency terms. Multiple brands areshown to be complementary, given their specialization in guaranteeingdifferent attributes of the product.

Evaluation of quality factors of bovine and chicken meat marinated with reduced sodium content

In many industrialized countries, including Brazil, sodium intake exceeds the nutritional recommendations. Excessive consumption is associated with hypertension and premature death by cardiovascular diseases. The industry's challenge is to produce products with reduced sodium that are similar to regular products in texture and flavor and consistent with consumers' dietary habits. The present study aimed at substituting 25 and 50% NaCl for KCl in marinated beef and chicken meat with the addition of aromatic herbs and spices. The following microbiological analyses were carried out: macronutrient, chemical composition, and sensorial analysis. The meats showed a reduction in NaCl contents without any changes in their physical and chemical characteristics, and the products´ quality and microbiological safety were maintained. Beef and chicken tenderness was maintained for both treatments. Furthermore, the use of 50% KCl did not cause any changes in the products' sensory quality, and the overall acceptance of both types of meat was maintained. Results showed that a reduction by 50% in the NaCl contents of marinated meat products with a combination of herbs and spices is possible. Future applications in other meat products and sausages are highly promising.

Salted lamb meat blanket of Petrolina-Pernambuco, Brazil: process and quality

Salted lamb meat blanket, originated from boning, salting, and drying of whole lamb carcass, was studied aiming at obtaining information that support the search for guarantees of origin for this typical regional product from the city of Petrolina-Pernambuco-Brazil. Data from three processing units were obtained, where it was observed the use of a traditional local technology that uses salting, an ancient preservation method; however, with a peculiar boning technique, resulting in a meat product with great potential for exploitation in the form of meat blanket. Based on the values of pH (6.22 ± 0.22), water activity (0.97 ± 0.02), and moisture (69.86 ± 2.26) lamb meat blanket is considered a perishable product, and consequently it requires the use of other preservation methods combined with salt, which along with the results of the microbiological analyses (absence of Salmonella sp, score <10 MPN/g of halophilic bacteria, total coliforms between 6.7 × 10³ and 5.2 × 10(6) FUC/g, and Staphylococcus from 8.1 × 10³ CFU/g at uncountable) reinforce the need of hygienic practices to ensure product safety. These results, together with the product notoriety and the organization of the sector are important factors in achieving Geographical Indication of the Salted lamb Meat blanket of Petrolina.

Meat yield and quality of Tanzania Shorthorn Zebu cattle finished on molasses/maize grain with agro-processing by-products in 90 days feedlot period

This study was conducted to evaluate the effects of feeding molasses or maize grain with agro-processing by-products on yield and quality of meat from Tanzania shorthorn zebu (TSZ) cattle. Forty five steers aged 2.5 to 3.0 years with 200 +/- 5.4 kg body weight were allocated into five dietary treatments namely hominy feed with molasses (HFMO), rice polishing with molasses (RPMO), hominy feed with maize meal (HFMM), rice polishing with maize meal (RPMM) and maize meal with molasses (MMMO). Ad libitum amount of each dietary treatment and hay were offered to nine steers for 90 days. Cooking loss (CL) and Warner Bratzler shear force (WBSF) values were determined on M. longissimus thoracis et lumborum aged for 3, 6, 9 and 12 days. Steers fed on HFMO diet had higher (P < 0.05) nutrient intake (86.39 MJ/d energy; 867 g/d CP), weight gain (919 g/d) and half carcass weight (75.8 kg) than those fed other diets. Meat of steers from all diets was tender with average WBSF values of 47.9 N cm^(−2). The CL (22.0 +/- 0.61%) and WBSF (53.4 +/- 0.70 N cm^(−2)) were highest in meat aged for 3 days followed by 6, 9 and 12 days. WBSF values for meat aged for 9 and 12 days from steers fed HFMO and RPMM diets were similar and lower than those on other dietary treatments x aging periods. Overall, molasses and hominy feed can be used to replace maize meal in feedlot finishing diets to spare its use in animal feeds.

Quality traits and lipid composition of meat from Nellore young bulls fed with different oils either protected or unprotected from rumen degradation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)