This trial was conducted to evaluate the quantitative carcass traits of Nellore, F1 Simmental × Nellore and F1 Angus × Nellore steers fed at maintenance level or ad libitum with 1% and 2% of the body weight in concentrate. The animals were allotted to the treatments in a completely randomized experimental design, in a 3 × 3 factorial arrangement. The animals fed the ad libitum diet with more concentrate had greater cold carcass weight, cold carcass yield and longissimus muscle area/100 kg of cold carcass weight when compared with animals fed the diet with low concentrate allowance. There was no difference between the ad libitum diets for all of the carcass cuts yields, except for top sirloin. Crossbred animals had cold carcass yield larger than the Nellore animals. F1 Angus × Nellore animals had greater rib fat thickness and smaller longissimus muscle area/100 kg than the F1 Simmental × Nellore cattle. The yield of commercial carcass cuts was not influenced by genetic group, except for the shoulder clod yield, which was smaller in crossbred animals compared with Nellore animals. The longissimus muscle area, rib fat thickness and rump fat, taken by ultrasound were influenced by the body weight of the animals. Crossbred animals fed diets with higher concentrate level produce carcasses most suitable for the requirements of the market.

We studied the phenotypic effects of polymorphisms at the MYF5 gene in a divergent F2 swine population and found that one polymorphism was due to an insertion and another to a deletion. The genotypes of 359 F2 animals were obtained and the Normal/Normal (NN) and Normal/Insertion (NI) genotypes analyzed to determine associations with phenotypic data for performance, carcass and meat quality traits. Significant differences were observed (p < 0.05) between NN and NI animals for drip (NN = 3.14 ± 1.56; NI = 3.69 ± 2.78%), cooking (NN = 32.26 ± 2.41; NI = 33.21 ± 2.31%) and total loss (NN = 34.16 ± 2.63 and NI = 34.97 ± 2.08%). The Deletion marker was not statistically tested. The results indicate that the allelic variant Insertion is associated with a deleterious effect on meat quality traits and should be monitored in marker assisted selection programs.

The PSS genotypes of 596 F2 pigs produced by initial mating of Brazilian commercial sows and native boars were characterized by PCR-RFLP and the pork quality traits were evaluated. Among the 596 pigs studied, 493 (82.7%) were NN and 103 (17.3%) were Nn. There were no differences between NN and Nn pigs in the following pork qualities: pHu (5.71 ± 0.16 vs 5.70 ± 0.11), intramuscular fat (1.55 ± 0.64% vs 1.65 ± 0.67%), shear force (5552 ± 878 g/1.2 cm vs 5507 ± 826 g/1.2 cm), lightness (44.96 ± 2.05 vs 45.01 ± 1.92), redness (0.64 ± 0.60 vs 0.79 ± 0.55), yellowness (6.62 ± 0.56 vs 6.65 ± 0.48), hue (84.28 ± 5.53 vs 83.41 ± 4.85), or chroma (6.68 ± 0.52 vs 6.73 ± 0.52). However, pork from Nn pigs had a significantly (p < 0.05) lower pH45 (6.41 ± 0.27 vs 6.51 ± 0.26) and greater drip (3.92 ± 1.90% vs 3.06 ± 1.60%), cooking (33.29 ± 2.26% vs 32.50 ± 2.54%) and total (35.67 ± 2.48% vs 34.01 ± 2.58%) loss compared to that of NN pigs. These results indicate that, even in divergent crosses, PSS gene carriers produce pork of poorer quality.

The PSS genotypes of 596 F2 pigs produced by initial mating of Brazilian native boars commercial sows and were characterized by PCR-RFLP and their carcass and performance traits were evaluated. Among the 596 animals analyzed, 493 (82.72%) were characterized as NN and 103 (17.28%) as Nn. With respect to carcass traits, Nn animals presented higher (p < 0.05) right half carcass weight, left half carcass weight, loin depth and loin eye area, and lower shoulder backfat thickness, backfat thickness between last and next to last but one lumbar vertebrae and backfat thickness after last rib at 6.5 cm from the midline compared to NN animals. Nn animals also showed (p < 0.05) higher values for most of the cut yields, indicating higher cutting yields for animals carrying the n allele and lower values for bacon depth, confirming lower fat deposition in carcass. In addition, Nn animals presented (p < 0.05) lower values for the performance trait weight at 105 days of age. These results indicate that animals carrying the PSS gene generate leaner carcasses, higher cut yields, and that the effects of the gene can be observed even in divergent crosses.

Bactérias láticas foram isoladas durante o processamento de salame tipo italiano, obtido a partir de duas plantas de processamento, no Estado do Paraná. Para o isolamento, foram utilizados os meios MRS, D-MRS e M17. Um total de 484 isolados teve sua atividade antibacteriana testada sobre Listeria monocytogenes (Laboratório de Microbiologia - UFV), Staphylococcus aureus (ATCC 25923), Salmonella enteritidis (ATCC 13076) e Escherichia coli (ATCC 25922), utilizando-se o deferred method. Cento e quinze isolados apresentaram zonas de inibição sobre, pelo menos, duas das bactérias indicadoras. Os isolados apresentaram maior inibição sobre Listeria monocytogenes. Os 45 isolados que apresentaram zonas de inibição sobre as quatro bactérias indicadoras foram identificados, utilizando-se o sistema Biolog. Lactobacillus bifermentans predominou entre os isolados identificados, obtidos no meio MRS, a partir das amostras das duas plantas de processamento.

Lactic acid bacteria were isolated in the MRS, D-MRS and M17 modified media, during the processing of Italian salami, obtained from two processing plants, in the State of Paraná. The 484 isolates were tested for their antibacterial activity against Listeria monocytogenes (Microbiology Laboratory-UFV), Staphylococcus aureus (ATCC 25923), Salmonella enteritidis (ATCC 13076) and Escherichia coli (ATCC 25922), by a deferred method. One hundred and fifteen isolates inhibited at least two of the pathogens. The isolates presented larger inhibition against L. monocytogenes. The 45 isolates with antagonistic action on the four indicator bacteria were identified by the system Biolog. Lactobacillus bifermentans prevailed among the isolates identified in MRS medium from the samples of the two processing plants.