Dietary integration with oregano (Origanum vulgare L.) essential oil improves growth rate and oxidative status in outdoor-reared, but not indoor-reared, pigs.

The effects of a diet supplemented with oregano essential oil on performance, oxidative status, pork quality traits and sensorial properties were evaluated. In two studies, 72 pigs in indoor or outdoor conditions were assigned to either a control diet or an identical diet supplemented with 0.2% oregano essential oil. Pigs reared outdoor showed lower live weight, average daily gain and average gain:feed ratio compared to indoor pigs. The oregano supplementation improved the growth performance of the outdoor- but not the indoor-reared animals. The serum oxidative status was influenced by the diet. A higher oxidative stability was observed in the oregano-supplemented groups. As for the rearing conditions, the data suggest that after an initial adapting period, the free-range farming systems could be better tolerated by pigs. Meat derived from pigs reared outdoor showed higher pH and a* values. Lightness was influenced by both the diet and the rearing conditions. The control group reared indoor showed shear force values higher than both supplemented groups, while no differences were detected with the control group reared outdoor. In the consumer test performed under blind conditions, the oregano groups achieved higher consistency scores compared with the control. Under informed conditions, the meat derived from the oregano-supplemented pigs reared outdoor received the highest scores for consistency and overall liking regardless of the rearing system. The same result for the overall liking score was obtained in the expectation test. The data obtained showed that dietary oregano essential oil can be effective in reducing performance losses due to the outdoor-rearing system, increasing the oxidative status of the animal and oxidative stability of the meat, without modifying the meat quality traits and improving consumer perceptions of the meat quality.

The occurrence of giant fibres in different muscles of two chicken genotypes.

1. The occurrence of Giant Fibres (GF) in three muscles (Pectoralis major (PM), Iliotibialis lateralis and Semimembranosus) with different types of energy metabolism was studied in slow- and fast-growing chicken strains. 2. A total of 20 one-day-old Leghorn chicks (slow-growing) and 20 broiler (Ross 508) chicks (fast-growing) were reared to 100 and 45 d, respectively. 3. A small percentage of GF was seen in pre rigor muscle samples even at 3 min post mortem in both genotypes and in all muscle types studied. 4. From 3 min to 24 h post mortem GF increased both in Leghorn and broiler chickens but to a different extent according to muscle type and genotype. 5. The highest GF 24 h post mortem value was found in the PM muscles belonging to the fast-growing broiler line. 6. It was concluded that every type of muscle can develop GF, but this phenomenon is more evident in the PM especially in animals selected for increased growth rate.

Evaluation of Aflatoxin M1 Enrichment Factor in Semihard Cow's Milk Cheese and Correlation with Cheese Yield.

HIGHLIGHTS: The aflatoxin M1 content in milk was not related to the enrichment factor. The enrichment factor in 45-day ripened semihard cheese was defined. The enrichment factor in cheese is affected by cheese yield.

Dietary oregano (Origanum vulgare L.) aqueous extract improves oxidative stability and consumer acceptance of meat enriched with CLA and n-3 PUFA in broilers.

The effect of a dietary oregano aqueous extract on meat fatty acid profile, quality, and consumer acceptance in chickens fed a diet rich in polyunsaturated fatty acids (PUFA) was evaluated in 3 consecutive trials.For each trial, 171 day-old Ross 308 chicks were randomly divided in replicates of 19 birds each and assigned to one of 3 experimental diets: 1) basal control diet, 2) basal diet supplemented with 0.2 g/kg of oregano aqueous extract, and 3) basal diet supplemented with 150 ppm of vitamin E (as positive control). To better analyze the antioxidant activity of both oregano and vitamin E, all the experimental diets were enriched with a fatty acid supplement consisting in a mixture of PUFA at the same dose (1.16 %) in both starter and finisher feeds. Oregano supplementation positively influenced (P < 0.05) broiler live performance. No differences were observed in physicochemical or proximal composition or in total fatty acid composition of breast meat. Dietary oregano influenced meat composition in terms of total phenolic content, antioxidant capacity, and thiobarbituric acid-reactive substances, improving meat resistance to oxidation, compared to both other groups. During consumer tests, meat from the 3 dietary groups obtained the same liking score in a blind session. Under informed condition, consumer perception was positively influenced by labeling for all the considered attributes. Furthermore, consumers showed a higher expectation for meat derived from chickens fed the oregano extract when compared to that deriving from the other 2 groups.Results obtained in the present study allow stating that using oregano aqueous extract in diets enriched with PUFA can represent a valid solution to increase live weight of chickens, improve resistance to oxidation of meat, and positively influence consumer perception of poultry meat.

An in vitro system for the comparison of excision and wet-dry swabbing for microbiological sampling of beef carcasses.

An in vitro system for the comparison of wet-dry swabbing and surface tissue excision was developed to ascertain whether the commonly accepted statement of the advantage (in terms of bacterial recovery) of the tissue excision method is also legitimate when different kinds of bacteria are used. A total of 1,770 sections (2.5 by 10 cm) of bovine skin were individually inoculated on the subcutaneous fat side by spreading various suspensions of marker organisms (nalidixic acid-resistant Escherichia coli, vancomycin-resistant Enterococcus faecalis, and methicillin-resistant Staphylococcus aureus) at different concentrations and sampled by two standard methods: cotton wet-dry swabbing and excision. Most counts from cuts sampled by excision were significantly (P < 0.05) higher than the wet-dry swabs; however, no differences were observed between the control and the sampling method when sections were inoculated with bacterial solutions at a concentration of 10(3) CFU/ml and sampled by excision. For sections inoculated with bacterial solutions at a concentration of 10(3) CFU/ml, counts given as log CFU/25 cm2 ranged from 1.97 (S. aureus sampled by wet-dry swab) to 3.06 (S. aureus sampled by excision). For sections inoculated at a concentration of 10(4), counts given as log CFU/25 cm(2) ranged from 2.15 (E. faecalis sampled by wet-dry swab) to 3.19 (S. aureus sampled by excision). For sections inoculated at 10(5), counts given as log CFU/25 cm(2) ranged from 2.94 (E. faecalis, wet-dry swab) to 3.98 (S. aureus, excision), and for sections inoculated at 106, counts given as log CFU/25 cm(2) ranged from 3.53 (E. coli, wet-dry swab) to 4.69 (S. aureus, excision). The proposed system, which enabled a considerable amount of samples to be analyzed under controlled experimental conditions and a large number of data to be generated in a short time, demonstrated among the tested microorganisms that whereas the excision method recovered the highest number of bacteria, control means were always (with the exception of an inoculum of 10(3)/ml) significantly higher than means from either of the sampling methods. Our results indicate that particular attention should be paid to the diverse microflora that can contaminate carcasses in a given slaughterhouse and that it is not appropriate to generalize by saying that the destructive method is the reference technique for the bacteriological sampling of carcasses in slaughterhouses, especially when the contamination is higher than 10(3) CFU/25 cm(2).

Dietary effects of a mix derived from oregano (Origanum vulgare L.) essential oil and sweet chestnut (Castanea sativa Mill.) wood extract on pig performance, oxidative status and pork quality traits.

The effects of a pre-formulated commercial plant extract mix, composed of equal parts of oregano essential oil and sweet chestnut wood extract, on performance, oxidative status and pork quality traits were evaluated. In two 155-d studies, 60 pigs (mean liveweight: 42.9 kg) were assigned to either a control diet (CTR) or an identical diet supplemented (0.2%) with the plant extract mix (OC). No differences in the growth rate were observed. Glutathione peroxidase and glutathione reductase activities in the OC muscles (Longissimus lumborum) were higher than in CTR muscles. The lipid oxidation of meat was lower in the OC group. In the cooked meat samples, OC animals had the lowest L* and H° values and the highest a* values. The OC meat received higher scores for colour, taste and overall liking in both the blind and the labelled consumer tests.

Species origin of milk in Italian mozzarella and Greek feta cheese.

Several animal species such as cattle, goats, sheep, and water buffalo provide milk for dairy products. We describe a simple procedure for detecting the species origin of milk used for cheese production. DNA was isolated from Italian mozzarella or Greek feta by sequential organic extractions and resin purification. This DNA was analyzed by polymerase chain reaction-restriction fragment length polymorphism as described previously for meat samples. This procedure differentiated mozzarella made from water buffalo milk and from less expensive bovine milk and also feta cheeses made from bovine, ovine, and caprine milk.

Seroprevalence and risk factors for Toxoplasma gondii infection on finishing swine reared in the Umbria region, central Italy.

Toxoplasma gondii is a worldwide zoonotic protozoan parasite and pork is considered the major meat source of Toxoplasma infection in humans. To determine the prevalence of infection of Toxoplasma gondii in pigs reared in the Umbria Region (central Italy), blood samples of 960 pigs from 10 different farms (96 for each farm) were randomly collected and tested for antibodies (IgG) against T. gondii using an IFA assay. Sera were screened at 1/16 titrr and the endpoint titre was determined. Farm management questionnaires were completed and used to develop descriptive statistics on the tested farms as well as to determine measures of association for risk factors for the presence of T. gondii-seropositive pigs. A total of 155 seropositive pigs (16.14%) were identified; within herds prevalence ranged from 8.33 to 25%. The statistical analysis identified all-in-all-out housing and cleaning method as risk factors for Toxoplasma infection.

Effect of genotype and rearing system on chicken behavior and muscle fiber characteristics.

The effect of the organic production system and genotype on chicken behavior and muscle fiber characteristics was assessed. Three hundred day-old male chicks from slow-growing (Leghorn), medium-growing (Kabir), and fast-growing (Ross 208) genotypes were assigned to 2 different production systems: conventional, housing in an indoor pen (0.12 m(2)/bird); and organic, housing in an indoor pen (0.12 m(2)/bird) with access to a grass paddock (4 m(2)/bird). Behavioral observations were recorded from 73 to 80 d of age in the morning and afternoon. At 81 d of age, blood samples were collected to measure lactate dehydrogenase and creatine kinase, and 20 birds per strain and rearing system were slaughtered. Samples of pectoralis major, ileotibialis lateralis, and semimembranosus muscles were obtained for histological evaluations. Behavioral observations showed that genetic selection of animals for a better growth rate modified their behavior, reducing kinetic activity. Indeed, Leghorn birds were characterized by moving activities, whereas Kabir and Ross strains were discriminated on the basis of their lying, standing, and eating activities, and these activities were strongly associated with energy conservation, growth, and muscle fiber characteristics. Fiber characteristics and muscle enzyme functions were affected by rearing system only in animals adapted to the organic system. Interesting results relative to Leghorn chickens are the presence of alpha-Red fiber in breast muscle and the increased cross-sectional area of the ileotibialis lateralis muscle, which together with behavioral data could affirm that this genotype is the most adapted to the organic rearing system.

Use of duplex polymerase chain reaction (duplex-PCR) technique to identify bovine and water buffalo milk used in making mozzarella cheese.

Molecular biology techniques have been used for species identification in food of animal origin in relatively recent years. A polymerase chain reaction (PCR) based method, the multiplex PCR, was recently applied to species identification in meat and meat products. It allows co-amplification of separate regions of a single gene or specific fragments, each typical of a different animal species in a single PCR reaction, using different pairs of primers in the same reaction mix. In the present paper, the duplex-PCR technique is proposed to identify bovine and water buffalo DNA in a single PCR assay in milk and mozzarella cheese (a typical Italian cheese, originally made from pure water buffalo milk). Because of its lower cost, undeclared bovine milk is added to water buffalo milk for making different kinds of mozzarella cheese. The results of this experiment indicate the applicability of this method, which showed an absolute specificity for the two species and a high sensitivity even down to low DNA concentrations (1 pg). In bovine and water buffalo mixtures of both milk and mozzarella cheese, the minimum concentration tested was 1% of bovine in water buffalo milk and water buffalo in bovine milk. The importance of the somatic cell content in raw milk is also discussed with special reference to the evaluation of mixtures (milk or cheese) of the two species.