Nuclear and mitochondrial DNA markers in traceability of retail beef samples

Several characteristics are important in a traceability system of animal products, such as age at slaughter, breed composition, besides information of the productive chain. In general, the certification agent records information about the animals and the system which it came from, although cannot guarantee that the slaughtering, meat processing and distribution are error proof. Besides, there is a differential price, at least at the international market, based on sex and breed composition of the animals. Genetic markers allow identification of characteristics controlled in the beef cattle traceability program, as sex and breed composition, in order to correctly identify and appraise the final product for the consumer. The hypothesis of this study was that the majority beef samples retailed in the local market originate from female with a great participation of zebu breeds. Therefore, the objective of this work was to characterize retail beef samples with DNA markers that identify cattle sex and breed composition. Within 10 beef shops localized in Pirassununga, SP, Brazil, 61 samples were collected, all were genotyped as harboring Bos taurus mitochondrial DNA and 18 were positive for the Y chromosome amplification (male). For the marker sat1711b-Msp I the frequency of the allele A was 0.278 and for the marker Lhr-Hha I the frequency of the allele T was 0.417. The results of sat1711b-Msp I and Lhr-Hha I allelic frequencies are suggestive that the proportion of indicus genome compared with the taurine genome in the market meat is smaller than the observed in the Nellore breed. The procedure described in this study identified sex and subspecies characteristics of beef meat samples, with potential application in meat products certification in special as an auxiliary tool in beef cattle traceability programs.

Mineral and vitamin content of beef, chicken, and turkey hydrolysates mineral and vitamin content of protein hydrolysates

The purpose of this study was to assess the concentration of vitamins and minerals in meat protein hydrolysates. Calcium, phosphorus and iron were analyzed by inductively coupled-plasma atomic emission spectrophotometry; vitamin C was analyzed by the reduction of cupric ions and vitamins B1 and B2 by fluorescence. Regarding minerals, the beef hydrolysate (BH) had more iron than the turkey hydrolysate (TH) and the chicken hydrolysate (CH); TH had a little more phosphorus. BH had the largest amount of vitamin C, and similar amounts of vitamins B1 and B2. The amount of these nutrients found in the hydrolysates suggests that it is possible to use them to enrich special dietary formulations.

Non-additive genetic effects on weights and performance of a Brazilian Bos taurus x Bos indicus beef composite

The aim of the present study was to evaluate the heterosis effects on weaning weight at 205 days (WW, N = 146,464), yearling weight at 390 days (YW, N = 69,315) and weight gain from weaning to yearling (WG, N = 59,307) in composite beef cattle. The fixed models were: RM, which included contemporary groups, class of age of dam, outcrossing percentages for direct and maternal effects, and additive direct and maternal ( AM) breed effects; R, RM model, minus AM breed effects, and H, RM model, minus additive breed effects. The estimates for W205 were in general positive (P < 0.01). The R and H models resulted in similar estimates, but they were very different from the ones estimated by the RM model. For W390, the R and H models resulted in general positive estimates (P < 0.05). For WG, the RM model resulted in general significant heterosis effects (P < 0.05). It can be concluded that the RM model seems to supply estimates of better quality (P < 0.01).

Characterization of mitochondrial genotypes in the foundation herd of the Canchim beef cattle breed

The Canchim (5/8 Charolais + 3/8 Zebu) beef cattle breed was developed at Southeast-Embrapa Cattle to take advantage of hybrid vigor and to combine the higher growth rate and beef quality of Charolais with tropical adaptations of Zebu. The development of three lineages (old, new, and crossbred) has increased its genetic basis. The genotypic origin (Bos taurus or Bos indicus) of the mitochondrial DNA (mtDNA) of the Canchim breed was unknown. We characterized the mtDNA genotype of this founder herd by allele-specific polymerase chain reaction. The 173 founder Zebu females (62 Indubrasil, 3 Guzerat, and 108 Nellore) and their 6749 offspring were identified. The frequency of B. indicus mtDNA ranged from 1.15 to 2.05% among the descendants (N = 6404) of each maternal line with available DNA, and among animals that were alive (N = 689) in December 2007 among the three lineages. Though mtDNA characterization can be used to direct animal selection, the low frequency of B. indicus mtDNA impairs the evaluation of its effects on production traits in these animals. The high prevalence of B. taurus mtDNA in Canchim proves that the founder Zebu females from the Indubrasil, Guzerat and Nellore breeds were obtained from crosses of Zebu sires with local B. taurus dams.

Effects of polymorphisms of LHR and FSHR genes on sexual precocity in a Bos taurus x Bos indicus beef composite population

The purpose of the present research was to investigate the effects of polymorphisms of luteinizing hormone receptor (LHR) and follicle-stimulating hormone receptor (FSHR) genes, evaluated by polymerase chain reaction-restriction fragment length polymorphism in European-Zebu composite beef heifers from six different breed compositions. The polymorphism site analysis from digestion with HhaI and AluI restriction endonucleases allowed the genotype identification for LHR (TT, CT and CC) and FSHR (GG, CG and CC) genes. A high frequency of heterozygous animals was recorded in all breed compositions for both genes, except in two compositions for LHR. The probability of pregnancy (PP) at first breeding was used to evaluate the polymorphism effect on sexual precocity. The PP was analyzed as a binary trait, with a value of 1 (success) assigned to heifers that were diagnosed pregnant by rectal palpation and a value of 0 (failure) assigned to those that were not pregnant at that time. Heterozygous heifers showed a higher pregnancy rate (67 and 66% for LHR and FSHR genes, respectively), but no significant effects were observed for the genes studied (P=0.9188 and 0.8831 for LHR and FSHR, respectively) on the PP. These results do not justify the inclusion of LHR and FSHR restriction fragment length polymorphism markers in selection programs for sexual precocity in beef heifers. Nevertheless, these markers make possible the genotype characterization and may be used in additional studies to evaluate the genetic structure in other bovine populations.

PRACTICAL USE OF MOLECULAR MARKERS IN BEEF AND DAIRY ZEBU CATTLE IN BRAZIL

Selection of zebu (Bos indicus) beef and dairy cattle in Brazil and the validation process of genetic markers for growth, carcass and meat quality traits and also for milk production, fat and protein milk content are discussed as concerned to the concepts and details of their use as auxiliary tools in selection processes. It is highlighted, also, the importance of right selection of ova donor cows for production of embryos to be transferred.

Involvement of Clostridium gasigenes and C. algidicarnis in `blown pack` spoilage of Brazilian vacuum-packed beef

The objectives of this study were to isolate psychrotrophic clostridia from Brazilian vacuum-packed beef cuts (spoiled or not) and to identify the isolates by using 16S rRNA gene sequencing. Anaerobic psychrotrophic microorganisms were also enumerated and samples were collected to verify the incidence of psychrotrophic clostridia in the abattoir environment. Vacuum-packed beef cuts (n = 8 grossly distended and n = 5 non-spoiled) and environmental samples were obtained from a beef packing plant located in the state of Sao Paulo, Brazil. Each sample was divided in three subsamples (exudate, beef surface and beef core) that were analyzed for vegetative forms, total spore-forming, and sulfide reducing spore-forming, both activated by alcohol and heat. Biochemical profiles of the isolates were obtained using API20A, with further identification using 16S rRNA gene sequencing. The growth temperature and the pH range were also assessed. Populations of psychrotrophic anaerobic vegetative microorganisms of up to 10(10) CFU/(g, mL or 100 cm(2)) were found in `blown pack` samples, while in non-spoiled samples populations of 10(5) CFU/(g, CFU/mL or CFU/100cm(2)) was found. Overall, a higher population of total spores and sulfide reducing spores activated by heat in spoiled samples was found. Clostridium gasigenes (n = 10) and C. algidicarnis (n = 2) were identified using 16S rRNA gene sequencing. Among the ten C. gasigenes isolates, six were from spoiled samples (C1, C2 and C9), two were isolated from non-spoiled samples (C4 and C5) and two were isolated from the hide and the abattoir corridor/beef cut conveyor belt. C. algidicarnis was recovered from spoiled beef packs (C2). Although some samples (C3, C7, C10 and C14) presented signs of `blown pack` spoilage, Clostridium was not recovered. C. algidicarnis (n = 1) and C. gasigenes (n = 9) isolates have shown a psychrotrophic behavior, grew in the range 6.2-8.2. This is the first report on the isolation of psychrotrophic Clostridium (C. gasigenes and C. algidicarnis) in Brazil. This study shows that psychrotrophic Clostridium may pose a risk for the stability of vacuum-packed beef produced in tropical countries during shelf-life and highlights the need of adopting control measures to reduce their incidence in abattoir and the occurrence of `blown pack` spoilage. (C) 2011 Elsevier B.V. All rights reserved.

Penetration of hydrolysed soy protein-added brine and its effect on yield and pH of beef steaks from the biceps femoris muscle

This study was aimed to evaluate the penetration behaviour of different brines with tumbled beef steaks from the biceps femoris muscle, specifically their interactions with pH and effects on yield. Six muscles from different animals, divided into origin (OP) and insertion (IP) portions, were cut into 60 steaks of 2.5 cm thickness and tumbled for 30 or 60 min. The steaks were tumbled with two brines, with (WTB/HSP) or without (WTB) hydrolysed soy protein (HSP), and steaks that were not tumbled with brine or water were used as controls. Brine penetration was verified by measuring the amount of dye-containing brine (absorbance at 627 nm) recovered from homogenates of four thin (2 mm) slices from the surface of the beef steaks after tumbling. The WTB/HSP steaks exhibited greater (P < 0.05) brine penetration when tumbled for 60 min than for 30 min. The OP steaks showed greater yield and lower pH (P < 0.05) than IP steaks. HSP-added brine increased the water absorption and retention in the first slices of the steaks, and its efficiency was increased with a longer tumbling time. The portion of the biceps femoris muscle used influenced brine absorption and retention, impacting meat yield. (C) 2010 Elsevier Ltd. All rights reserved.

Fate of Surface-Inoculated Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium on Kippered Beef during Extended Storage at Refrigeration and Abusive Temperatures

The behavior of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium on kippered beef was evaluated. Individual pieces of the product were separately inoculated on the top and bottom surfaces with each three- to six-strain pathogen cocktail at ca. 6.0 log CFU per piece and stored at 4, 10, 21, or 30 degrees C for up to 28 days in each of two trials. When kippered beef was inoculated with E coli O157:H7, Salmonella Typhimurium, or L. monocytogenes and stored at 4, 10, 2 1, or 30 degrees C for up to 28 days, pathogen numbers decreased ca. 0.4 to 0.9, 1.0 to 1.8, 3.0 to >= 5.25, and >= 5.0 to 5.25 log CFU per piece, respectively. Average D-values for E. coli O157:H7, Salmonella Typhimurium, and L. monocytogenes stored at 4 to 30 degrees C for 28 days were ca. 41 to 4.6, 40.8 to 5.3, and 29.5 to 4.3 days, respectively. As expected, the higher the storage temperature, the greater the level and rate of inactivation for all three pathogens. These data establish that kippered beef does not provide an environment conducive to proliferation of these pathogens.

Natural antioxidants protecting irradiated beef burgers from lipid oxidation

The effect of butylated hydroxytoluene/butylated hydroxyanisole blend (BHT/BHA), and rosemary and oregano extracts, added individually or in combination, on lipid oxidation and fatty acid composition was investigated on irradiated frozen beef burgers. Irradiation treatment was carried out using a (60)CO semi-industrial irradiator at doses of 6, 7 and 8 kGy, and then the treated meat samples were stored at -20 degrees C for 90 days. Lipid oxidation and fatty acid composition of beef samples were evaluated by measurement of TBARS and gas chromatography, respectively. The results of the experiment showed that rosemary extract, applied alone and in combination with either BHT/BHA or oregano extracts was more effective in maintaining a low oxidation level in the samples compared to oregano extract used individually or in combination with BHT/BHA. Results also showed no significant differences (p > 0.05) in fatty acid composition in all analyzed samples, although some changes in terms of decreased PUFA and MUFA, beside of slight increase of SFA content were observed. However, these differences do not correlate positively neither with the irradiation dose nor the type of antioxidant. Thus, there is a potential application of these spices as natural antioxidants in irradiated meats. (C) 2009 Elsevier Ltd. All rights reserved.

Effects of natural antioxidants on the lipid profile of electron beam-irradiated beef burgers

The purpose of this study was to assess the efficacy of rosemary and oregano extracts in avoiding oxidative changes in beef burgers, and to evaluate the fatty acid profile of these products after electron beam exposition. Extracts, individually or in combination, were added to beef burgers and compared to synthetic antioxidants commonly used in food (butylated hydroxytoluene, butylated hydroxyanisole). The ground beef were submitted to electron beam irradiation at doses of 0, 3.5 and 7 kGy, and stored for 90 days. At regular time intervals, lipid oxidation and fatty acid composition were evaluated through measurement of thiobarbituric acid-reactive substances (TBARS) and gas chromatography, respectively. The results indicate that, although the irradiation process triggers an increase in the lipid oxidation ratio expressed by TBARS values, great changes in the fatty acid profiles were not observed; instead, they continued to present characteristics very similar to that of non-irradiated beef. Thus, as irradiation doses of up to 7 kGy for frozen meat can make foods safe from foodborne pathogens, natural antioxidants derived from spices are able to reduce and avoid lipid changes that may cause a deterioration of the sensory quality of these foods, and these natural extracts offer a good choice for replacing synthetic additives.

Consumer`s evaluation of the effects of gamma irradiation and natural antioxidants on general acceptance of frozen beef burger

The effect of addition of rosemary and oregano extracts on the sensory quality of irradiated beef burger was investigated. Batches of beef burgers were prepared with 400 ppm of rosemary or oregano extract and a group prepared with 200 ppm of synthetic butyl-hydroxytoluene (BHT)/butyl-hydroxy-anisol (BHA) was used as a control. Half of each formulation was irradiated at the maximum dose allowed for frozen meat (7 kGy). Samples were kept under frozen conditions (-20 degrees C) during the whole storage period, including during irradiation. Two analyses were performed after 20 and 90 days to verify the influence of the addition of the different types of antioxidants and the effect of irradiation and storage time on the acceptance of the product. Thirty-three and thirty-four untrained panelists were invited to participate in the first and second test, respectively. A structured hedonic scale ranging from 1 to 9 points was used in both analyses. BHT/BHA formulation obtained the highest score (6.73) and regarding the natural antioxidants, oregano received better acceptance (6.36). Irradiated samples formulated with oregano received a lower score, 6.03 in the first test and 5.06 in the second one, compared to the non-irradiated sample (6.36 and 5.79). In the second test (90 days), the sample formulated with BHT/BHA and which was irradiated received a higher score (6.59) when compared to the non-irradiated one (5.85). In both tests, the irradiated samples formulated with rosemary extract obtained a better score compared to the non-irradiated one, the scores being 5.00-3.82 and 5.00-3.76 in the first and second test, respectively. Our results allowed us to conclude that the natural antioxidants, rosemary and oregano extracts, present a good alternative for replacing synthetic additives in food industries, and that the irradiation process, in some cases, may help to enhance the sensory quality of food. (C) 2008 Elsevier Ltd. All rights reserved.

Parasitic dynamics of gastrointestinal nematode infection in the periparturient period of beef cattle in the State of Para

The experiment was conducted to investigate the dynamics of infection by gastrointestinal nematodes during the periparturition period in cows. One hundred and six beef cows were divided into two groups: G I was formed by 42 cows of one and two parturitions, and G2 by 76 cows of three or more parturitions. From the 120 days pre partum until the 90 days post partum, feces were collected for faecal egg counts (EPG) while blood was collected to determine the packed cell volume and hemoglobin levels of each animal, with monthly intervals. In the same intervals the body condition scores (BCS) were evaluated. The mean values standard deviation of the EPG for Cl were equal to 19.4 +/- 42.9, and for G2 31.1 +/- 68.0. No significant differences were observed between Cl and G2 in relation to EPC; and hematological parameters, which remained within normal patterns for both groups. The two groups had higher counts of EPG in the post partum period than in the pre partum period, with averages of 32.5 +/- 55.5 and 51.5 +/- 84.8 for groups Cl and G2, respectively. A significant difference (p < 0.05) in the parameters was observed when comparing the pre and post partum within each group studied resulting in declining values of blood and body score and an increase in EPG in the post partum. The results suggest that the cows may be more susceptible to infection by nematodes from giving birth up to 90 days post partum. However, adult cows, when well-managed, are not an important factor in the epidemiology of gastrointestinal nematodes, even in the post partum period.

Beef Carcass Contamination by Shiga Toxin-Producing Escherichia coli Strains in an Abattoir in Brazil: Characterization and Resistance to Antimicrobial Drugs

A survey was performed to estimate the frequency of Escherichia coli and Shiga toxin-producing E. coli (STEC) in carcasses obtained from an abattoir in Brazil between February 2006 and June 2007. A total of 216 beef carcasses were sampled at three stages of the slaughter process-preevisceration, postevisceration, and postprocessing-during the rain and dry seasons, respectively. Of the carcasses sampled, 58%, were preevisceration E. coli positive, 38% were postevisceration positive, and 32% postprocessing positive. At the postprocessing stage, the isolation of E. coli was twice as high in the rain season. E. coli was isolated from 85 carcasses of which only 3 (1.4%) were positive for stx-encoding genes. No E. coli O157 serogroup isolates were detected. No antimicrobial resistance was found in nine of the isolates (10% of the total). The most frequent resistances were seen against cephalothin (78%), streptomycin (38%), nalidixic acid (36%), and tetracycline (30%). Multidrug resistance (MDR) to three or more antimicrobial agents was determined in 28 (33%) E. coli isolates. The presence of STEC and MDR strains among the isolates in the beef carcasses emphasizes the importance of proper handling to prevent carcass contamination.

PHYSICAL AND CHEMICAL CHARACTERISTICS OF FROZEN GROUND BEEF AND AGED BEEF MEAT FROM BOS INDICUS STEERS SUPPLEMENTED WITH alpha-TOCOPHEROL ACETATE

The objective of this study was to evaluate the effects of diet supplementation with vitamin E on the physical and chemical characteristics of ground, frozen and stored or aged Quadriceps femoris (QF) and Longissimus dorsi (LD) muscles from Nellore steers fed high concentrate diets. Muscles were obtained from 24 animals that were 30 months old with a mean live weight of 279 kg. Half of the animals received daily doses of 1,000 mg of alpha-tocopherol acetate (VIT E) per head per day that was added to 100 g of corn meal. The other half received 100 g of corn meal without the antioxidant. Twenty-four hours after slaughtering, QF samples from each animal were ground, frozen and stored for up to 6 months. In addition, 4 samples from the LD of each animal were vacuum packed individually and kept for 21 days. All samples were analyzed to determine the pH, color and water-holding-capacity. The VIT E supplementation improved only the water loss characteristics of frozen ground QF and did not have any positive effect on the physical-chemical characteristics of the aged LD.