Claudia Russo

EU carcass classification system: carcass and meat quality in light lambs.

Sixty male Apenninica suckling lambs carcasses were studied in order to evaluate the relationship between carcass and meat quality of light lambs as evaluated according to the EU Mediterranean classification system. Increased carcass weight (6-12 kg) was accompanied by greater carcass size and compactness and reduced bone percentage. Moreover the meat quality was similar with the increase of carcass weight in terms of colour, water holding capacity and suitability for domestic storage. No differences for the examined parameters were found between carcasses classified in quality 1 and 2. The EU Mediterranean classification system appears to be unrelated to the quality of the merchandized meat.

Omega-3 polyunsaturated fatty acid supplements and ambulatory blood pressure monitoring parameters in patients with mild essential hypertension

Objective To evaluate the effects of low doses of oM-3 polyunsaturated fatty acids on ambulatory blood pressure monitoring parameters in a group of mild essential hypertensives. Patients We studied 24 consecutive essential hypertensive patients from our outpatient clinic with mild hypertension (diastolic blood pressure ± 105 mmHg), no previous treatment for 4 weeks at least and no other disease. Methods After a 3-month run-in period, the patients entered an intervention phase and were given 3g oM-3 polyunsaturated fatty acids (85% eicosapentaenoic and docosahexaenoic acid concentrate) daily for 4 months; this phase was followed by a 4-month washout period. Ambulatory blood pressure monitoring was performed at the end of each phase; erythrocyte membrane fatty acids were assessed to check compliance. Results After 4 months of treatment, erythrocyte oM-3 polyunsaturated fatty acids significantly increased but average systolic and diastolic blood pressure and the heart rate did not significantly change; no significant variations were recorded in blood pressure or heart rate variability (assessed as blood pressure and heart rate SD) nor in the diurnal blood pressure rhythm. After washout, a significant decrease was observed in erythrocyte oM-3 polyunsaturated fatty acids but the ambulatory blood pressure monitoring parameters were not substantially modified. Conclusions The present data show that low doses of oM-3 polyunsaturated fatty acids as a single treatment are not effective in lowering blood pressure or the heart rate in mild essential hypertensive patients, despite a significant change in fatty acid cell membrane composition. Nor does this treatment seem likely to affect blood pressure variability or the diurnal rhythm.

Effect of an outdoor rearing system on the welfare, growth performance, carcass and meat quality of a slow-growing rabbit population

The effect of Outdoor or Indoor housing systems on the growth, welfare and carcass and meat quality of a local rabbit population was investigated. The slaughter age was 103±2days. Open-field tests showed an effective capacity of the Outdoor group to combat stressors. Compared to Indoor rabbits, Outdoor rabbits showed better growth performance and higher slaughter weight (SW) (2535 vs 2137g; P<0.01). Outdoor housing conditions increased the physical activity of rabbits and their hind legs were more developed (36.1% vs 34.9%; P<0.01). Slaughter yield was lower in Outdoor rabbits (57.8% vs 58.4% SW; P<0.05) due to the higher skin proportion (17.2% vs 15.6% SW; P<0.05). Outdoor rabbit meat showed lower L∗ value (L. lumborum: 55.6 vs 59.2; P<0.01; B. femoris: 53.0 vs 55.5; P<0.01) and cooking loss (L. lumborum: 15.9% vs 18.1%; P<0.05). Outdoor rabbit hind leg meat was characterized by lower water (74.5% vs 75.1%; P<0.01) and higher protein (22.9% vs 22.6%; P<0.01) and fat (1.4% vs 1.1%; P<0.01) contents; lipids were lower in SFA and higher in MUFA. Outdoor rearing seems to be a possible alternative housing system that allays the ethical concerns of modern consumers while also providing good meat quality.

Effect of stocking density and group size on growth performance, carcass traits and meat quality of outdoor-reared rabbits

The effect of stocking density (16 rabbits/m(2), 5 rabbits/m(2), 2.5 rabbits/m(2), n = 60, Experiment 1) and group size (4 rabbits/cage, 8 rabbits/cage, 16 rabbits/cage, n = 88, Experiment 2) on productive performance, carcass and meat quality of a slow-growing rabbit population reared outdoors was investigated in two experiments. The highest stocking density induced the highest skin percentage. Lower stocking densities showed lower lightness of Biceps femoris and higher redness of Longissimus lumborum muscles. Four rabbits/cage group (Experiment 2) showed the highest daily weight gain and slaughter weight and the lowest skin percentage. The muscles of 16 rabbits/cage showed significantly higher pHu than 8 and 4 rabbits/cage. BF of 16 and 4 rabbits/cage showed higher L* value. Productive performance and meat quality of rabbits reared outdoors improved in low group size while stocking density needs more experiments. The best combination of density, group size and total available surface that showed the best production and carcass traits was of 5 rabbits/m(2), 4 rabbits/cage, and 0.8m(2).

Meat quality traits of longissimus thoracis, semitendinosus and triceps brachii muscles from Chianina beef cattle slaughtered at two different ages

Abstract The aim of this experiment was to study the effects of muscle and slaughtering age on some meat quality traits of forty-eight carcasses of Chianina beef cattle raised on the same farm and slaughtered at an age ranging between 18 and 21 months. After the usual commercial ageing period for Chianina carcasses, longissimus thoracis, semitendinosus and triceps brachii muscles were taken and analyzed instrumentally for pH, meat color, water holding capacity, tenderness and chemical composition. To compare the quality characteristics of the three muscles at different age, all data were subdivided in two groups: slaughtering age 18-19 months (n=25) and 20-21 months (n=23). Quality characteristics of meat derived from the three muscles analyzed were different: semitendinosus muscle showed higher values of Lightness (L*) and Hue (H*), thus lighter and paler meat, but was less tender and had a higher cooking loss. Meat derived from triceps brachii muscle had the lowest values of Lightness (L*) and Hue (H*) thus meat slightly darker; with regard to the other quality parameters, longissimus thoracis gave more tender meat with better water holding capacity than triceps brachii. The meat analyzed had a very low content of intramuscular fat (expressed as ether extract (%)), a very well-known characteristic of Chianina meat. The comparison between meat derived from 18-19 month old beef and from 20-21 month old beef shows that only redness (a*) and Chroma (C*) increased significantly with the increase in slaughtering age, but these results do not induce differences in meat color appreciation, as shown by the similar values of Lightness (L*) and Hue (H*). Water holding capacity, tenderness and chemical composition were not influenced by slaughtering age.

Effects of low doses of dexamethasone on productive traits and meat quality of veal calves

An experimental administration of dexamethasone was carried out on 15 veal calves in order to assess the rôle of low doses of exogenous glucocorticoids on productive traits and meat quality. Three groups, of five veal calves each, were formed : one group received oral dexamethasone (0·4 mg per calf per day for 25 days), another intramuscular (i. m.) dexamethasone (2 mg at days 14 and 21), and the third was the control. Calves were slaughtered at 165 days of age (day 31). Food conversion ratio (FCR), hot dressing percentage (HDP), chilled dressing percentage (CDP) and shrinkage were determined. From all carcasses, samples of m. longissimus thoracis (between the 8th and 10th rib) were taken in order to evaluate the chemical composition and some organoleptic characteristics : meat colour, waterholding capacity and tenderness. The animals treated with oral dexamethasone showed the lowest daily weight gain ( P < 0·05) and the poorest FCR ( P < 0·05). Hot dressing percentage, cold dressing percentage and shrinkage were not affected by the oral treatment. The i. m. injections of dexamethasone did not influence the overall performance. Muscle chemical composition and pH were not affected by the treatments; the meat of calves treated with oral dexamethasone was significantly lighter ( P < 0·05) and tended to be paler, while i. m. treatment induced intermediate characteristics. The shear force of the meat was rather low. Shear force of cooked meat from animals treated with dexamethasone (both oral and i. m.) was significantly lower than the control (P < 0·05). Treatment with dexamethasone i. m. induced a decrease in water-holding capacity; the oral treatment had no effect on this parameter.

Influence of partial replacement of soya bean meal by faba beans or peas in heavy pigs diet on meat quality, residual anti-nutritional factors and phytoestrogen content

The study evaluated the partial substitution of soybean meal by faba beans (18%) or peas (20%) as additional protein sources in diets destined for typical Italian heavy pig production. It compared animal performances, meat quality, the presence of residual anti-nutritional factors (ANF) and phytoestrogens in plasma and meat and the possible effects on pig health, by evaluating oxidative, inflammatory and pro-atherogenic markers. The results showed that the productive performances, expressed as body weight and feed conversion ratio, of pigs fed with faba bean and pea diets were similar to those of pigs fed only the soybean meal. Meat quality of pigs fed with the three diets was similar in colour, water-holding capacity, tenderness and chemical composition. Despite the higher levels of phytoestrogen in the plasma of pigs fed only the soybean meal, phytoestrogen concentration in the muscle was equivalent to that of animals fed diets with faba beans, whereas pigs fed a diet with peas showed a lower concentration. Inflammation and pro-atherogenic parameters did not show significant differences among the three diets. Overall, the partial substitution of soybean meal by faba beans appears more interesting than with peas, particularly in relation to the higher amount of polyphenols in the diet and the highest concentration of phytoestrogens found in the plasma and muscle of animals, while the pyrimidine anti-nutritional compounds present in the diet did not appear to accumulate and had no effect on the growth performance of animals.

Effect of Islamic ritual slaughter on beef quality.

Abstract The aim of this study was to evaluate several quality characteristics of meat obtained from 20 Limousine calves slaughtered either according to conventional methods (n=10) or by the Islamic ritual slaughtering procedure (n=10). After 7 days of ageing under vacuum, pH, drip loss, colour and oxymyoglobin percentage were measured on longissimus dorsi muscle after 2h, 2 and 6 days of storage to study their evolution. With conventional slaughter pH remained stable until the 6th day of storage, while with ritual slaughter it increased from the 2nd to 6th day of storage. Drip loss increased considerably from the 2nd to 6th day of storage in conventional slaughter, while in ritual slaughter the drip loss increase was lower. Meat colour was not influenced by the slaughtering system but only by the different lengths of storage.

Genetic variability of meat quality traits in Chianina beef cattle

Abstract The heritability of quality traits (chemical composition, colour, tenderness and water-holding capacity) of the meat deriving from three muscles (Triceps brachii, Longissimus dorsi and Semitendinosus) was evaluated in 92 young Chianina bulls. The animals were raised on two farms with different feeding programs, and were slaughtered at approximately 19 months of age. Single pair correlations were considered in order to evidence the relationships between the same traits detected in the three muscles and between all the traits of the same muscle. The h2 values range from 0.00 to 0.24 for the chemical composition, from 0.00 to 0.19 for colour parameters, from 0.03 to 0.31 for those observed after 48 h, and from 0.00 to 0.08 for tenderness and water-holding capacity. The values were not homogeneous for the three muscles. The most heritable trait was yellowness (b*48) in all three muscles, with values of 0.11 in the Longissimus dorsi, 0.23 in the Semitendinosus, and 0.31 in the Triceps brachii. Conversely, tenderness appeared to have a low heritability, as did the parameters relating to the water-holding capacity. Colour traits observed before and after 48 h of storage generally were significantly and positively correlated, indicating that certain colour characteristics are maintained even after 48 h of storage. There was not always a close relationship between the traits of each muscles: significant correlations existed between the Triceps brachii and the Longissimus dorsi muscles, confirming the similar quality traits of their meat, while there were considerable differences between these muscles and the Semitendinosus.

Effect of rearing technique in outdoor floor cage on slow growing rabbit population performance

Abstract The aim of this research was to test the effect of floor cage in outdoor pen on productive performance and carcass characteristics of a rabbit local population characterized by slow growing rate. A sample of 48 rabbits female 57 days old was divided into two groups: Indoor group, housed in colony cages indoor at the density of 14 animals/m2 and Outdoor group, in wire net floor colony cages in outdoor pen, at the density of 5 animals/m2. The animals were fed a commercial feed and ad libitum alfa-alfa hay. Individual live weight and cage feed consumption were checked every week and feed conversion ratio was calculated; at 103 ± 2 days old a sample of 24 animals was slaughtered and carcass traits were recorded. The results showed that the Outdoor group had the highest live weight and the best daily weight gain, together with an higher feed intake. Outdoor group showed the lower mortality, the higher slaughtering weight, the higher reference carcass incidence and hind leg percentage. These favourable results encouraged this kind of rearing system characterized also by lower investment costs.