O. Franci

Quality outline of European sea bass (Dicentrarchus labrax) reared in Italy: shelf life, edible yield, nutritional and dietetic traits

Abstract The final product quality of European sea bass was outlined through some results on (1) quality traits in a large range of body size (80–1580 g weight) and (2) changes in sensorial and objective quality parameters during shelf life, as influenced by the rearing system, storage and stress. More than 500 European sea bass of commercial size were used in several trials. All fish were subjected to linear and weight measurements. In most trials, sea bass were stored at 4 or 1 °C with ice cover and evaluated every 24 h after death until spoilage for the EU freshness classes and for a large number of physical and chemical quality traits (rigor index, dielectric properties, muscle and eye liquor pH, water-holding capacity (WHC), water, protein, ash, total, neutral and polar lipids, cholesterol, fatty acids, malonaldehyde, adenine nucleotides and biogenic amines). Fillets showed on the average isometric growth, but the dorsal muscle grew faster and the ventral one slower than the body weight. A moderate corpulence increase in fish shape during growth emerged. The size range from 500 to 940 g—when incidences of fillets and dorsal muscle were higher than 48% and 31% and that of viscera was lower than 10%—can be suggested for having sea bass with the better edible portion yield. Protein and ash contents of muscle remained constant with body weight increase, while moisture and cholesterol content decreased; total lipid moderately increased along with the triglyceride incidence. On the whole, the muscular fatty acid pattern determined good indexes of atherogenicity (IA) and mostly of thrombogenicity (IT). Sea bass stored at 4 or 1 °C with ice cover had a 6- and 10-day shelf life, respectively. In the first 2 and 3 days, respectively, sea bass were Extra (always with 100% rigor index) and had Fish Tester values decreasing to 64 or 73, respectively, and negligible levels of malonaldehyde (MDA) and biogenic amines. In the following 2 and 3 days, respectively, sea bass became A fish (good quality), with decrease of rigor index (IR) and Fish Tester (FT) and slight increase in malonaldehyde and putrescine contents. In the following 2 and 4 days, respectively, sea bass became B fish (bad quality), with further decrease of rigor index and Fish Tester and moderate increase of malonaldehyde and putrescine. Thereafter, fish were unfit for human consumption. No difference in quality parameter of fish reared in aerated (4.3 ppm O2) or hyperoxic (9.3 ppm) conditions was found. Stress shortened the pre- and post-rigor phase and shelf life.

Performance of Cinta Senese pigs reared outdoors and indoors. 1. Meat and subcutaneous fat characteristics

The effects of rearing system on tissue composition of a sample joint and on chemical-physical traits of meat and subcutaneous fat were studied in an Italian local pig breed. Forty-six Cinta Senese pigs were used; 17 pigs were reared on wood pasture, 29 pigs were reared in pens and fed commercial mixtures. Weight at slaughter was 136.2 and 127.7 kg for indoor and outdoor-pigs respectively. For sample joint composition outdoor-pigs showed a lower percentage of Longissimus lumborum (Ll) (46% vs. 48%) and higher percentages of intermuscular fat (7.2% vs. 4.7%) and bone (20.9% vs. 19.2%). In Ll outdoor-pigs showed higher percentages of intramuscular fat (4.04% vs. 3.29%) and crude protein (23.5% vs. 22.8%), lower drip and cooking losses by oven (0.66% vs. 2.14% and 28.6% vs. 32.3% respectively) and higher cooking loss by water-bath (30.3% vs. 26.6%). Lower values of L* (45.8 vs. 50.1) and higher values of a* (14.9 vs. 11.8) and chroma (15.9 vs. 12.8) were recorded on Ll of outdoor-pigs. Subcutaneous fat of outdoor-pigs showed higher percentages of MUFA (55.1% vs. 53.3%) and PUFA (13.2% vs. 10.4%). Outdoor-pigs had higher PUFA/SFA ratio (0.43 vs. 0.29).

Comparison of the performances of Nero Siciliano pigs reared indoors and outdoors: 2. Joints composition, meat and fat traits

A study on the effect of rearing system on tissue composition of principal joints and chemical-physical traits of meat and subcutaneous fat, was carried out on a local pig breed. A total of 78 Nero Siciliano pigs was used; 41 pigs were reared in woods, 37 pigs were reared in pens and fed a commercial diet. Weight at slaughter was 101.9 and 88.2 kg for indoor and outdoor pigs, respectively. Means were estimated at 77 kg of live weight. At ham dissection outdoor-pigs showed higher percentages of lean (58% vs. 55%) and lower subcutaneous fat (31% vs. 34%). In Longissimus lumborum outdoor-pigs showed a higher intramuscular fat percentage (4.3% vs. 3.3%), a lower protein content (22.2% vs. 23.4%), and higher free water (9.6 vs. 7.9 cm(2)). Outdoor pigs produced more light (L(*)=50 vs. 46.7) and more yellow (b(*)=5.84 vs. 4.88) meat. Subcutaneous fat of outdoor pigs showed higher percentages of MUFA (53.3% vs. 47.2%) and lower percentages of PUFA (10.85% vs. 14.45%), no differences were found for n-3 PUFA. Outdoor-pigs had lower atherogenicity (0.48 vs. 0.53) and thrombogenicity (1.03 vs. 1.21) indices.

Performance of Cinta Senese pigs and their crosses with Large White. 1 Muscle and subcutaneous fat characteristics

Twenty-nine Cinta Senese (CS), 29 Large WhitexCinta Senese (LWxCS) and 12 Large White (LW) pigs were reared indoors and fed a commercial mixture. After slaughter (at avg. weight of 136, 139, 155 kg for CS, LWxCS, LW, respectively), a portion of the loin (sample cut) was dissected into lean and Longissimus lumborum (LL), intermuscular fat and bone. Chemical and physical analyses were conducted on LL. Chemical composition and fatty acid profile were determined on the outer layer of backfat. CS pigs had the highest percentage of bone and the lowest of lean in the sample cut, LWxCS showing intermediate values between parental breeds. In LL, CS showed lower moisture (73.23% vs. 74.28%) and higher fat content (3.19% vs. 0.87%) than LW; pH(24) was higher in CS (5.78) than in LWxCS (5.67) and LW (5.50); meat was more red in CS and LWxCS than in LW; CS showed higher water holding capacity than LW, with LWxCS at an intermediate position; raw meat was tougher in CS than in LW, but differences disappeared after cooking. In backfat CS had lower moisture (6.5% vs. 6.9% and 7.8%) and higher lipid content (81.4 vs. 78.1 and 77.5%) than LWxCS and LW; concerning fatty acid composition, CS showed less SFA (saturated fatty acids; 36.2% vs. 37.12% and 37.7%) than the other two genotypes, and, together with LWxCS, less PUFA (polyunsaturated fatty acids; 10.4% and 10.2% vs. 11.1%) and more oleic acid (50.3% and 49.8% vs. 48.5%) than LW. Overall, evidence of additive genetic effects was present for most qualitative parameters with crosses showing intermediate values between parental breeds.

Evolution of chemical composition, somatic cell count and renneting properties of the milk of Massese ewes

Abstract The experiment was carried out on 52 lactations of 37 multiparous Massese ewes. Because of the mating practice of the breed, three types of lactation were detected: Type 1, a short lactation initiated in autumn; Type 2, a short lactation initiated in spring, following the Type 1 lactation; Type 3, a long lactation initiated in autumn. Milk yield was recorded weekly, starting not before the eighth day from lambing. On a total 984 milk samples, contents of fat, protein, casein and lactose, SCC, pH and clotting parameters (R, K20 and A30) were determined. Data were analysed by a mixed model including lactation order, lactation type, DIM, and individual lactation as random effects. Protein and casein content increased from the second to fifth lactation; the highest fat content was detected in the sixth lactation and over; milk of fourth lactation had higher SCC and worse renneting properties than that of second lactation. The pattern of evolution of parameters within the three types of lactation showed that the increase of nutrients with DIM was particularly noticeable for fat content in the Type 2 lactation (spring/short) which exhibited, at an average of 94 DIM, 1.5 percentage units above the other two types. Evolution of lactodynamographic parameters indicates that generally there was a substantial improvement in cheese-making suitability during the first 2–3 months postpartum, and a worsening thereafter. The Type 2 lactation yielded milk with better renneting properties, particularly with respect to milk obtained during the same season from ewes that had an autumn delivery. This suggested that the newly started milk from the spring lactation could have a corrective effect on the total amount of bulk milk produced, a possible advantage for the Massese breed, which is characterised by a particularly pronounced deseasonalisation of lambings.

Productivity of Cinta Senese and Large White x Cinta Senese pigs reared outdoors in woodlands and indoors. 2. Slaughter and carcass traits

Abstract The aim of this paper was to study slaughter and carcass traits of Cinta Senese pigs, both pure and crossbred with Large White, reared outdoors in woodland and indoors. Sixteen Cinta Senese (CS) and 16 Large White x Cinta Senese (LWxCS) pigs were reared outdoors (OUT) on woodland pastures with some food supplementation; 70 animals (29 CS, 29 LWxCS and 12 LW) were reared indoors (IN), allotted in pens for genetic type and sex. Pigs were slaughtered at about 140 kg of live weight and at an age greater than 8 months. After slaughter, carcass length, thorax depth, number of vertebrae and backfat thickness were measured, and carcasses were dissected into lean, fat and bone cuts. Average daily gain to slaughter differed markedly among the five GTxRS combinations (598; 512; 438; 338; 250 g/d, respectively for LW-IN; LWxCS-IN; CS-IN; LWxCS-OUT; CS-OUT). LWxCS-IN and LWxCS-OUT had respectively the highest and the lowest dressing percentages (83.3% and 80.1%). A greater compactness of CS carcasses was evident from the length to depth ratio. In both farming systems CS pigs had the thickest backfat, and their differences with the other genetic types increased proportionally according to a cranio-caudal gradient. Moreover, CS pigs showed lower percentage of lean cuts and a higher percentage of fat cuts, than the other breeds. In the indoor system an additive effect was evident, with crossbred pigs showing lean cuts yields (62.8%) of almost intermediate value with respect to the parental breeds (57.7% for CS and 69.1% for LW). Some effects of the availability of woodland pastures on growth and carcass composition were also observed, particularly showing CS-OUT pigs’ higher percentage of backfat and kidney fat, and lower percentage of loin and shoulder than the CS-IN ones.

Productivity of Cinta Senese and Large White x Cinta Senese pigs reared outdoor on woodlands and indoor. 1. Growth and somatic development

Abstract Twenty-nine Cinta Senese (CS), 12 Large White (LW) and 29 LWxCS pigs were reared indoor and group fed on commercial mixtures in pens averaging 6 animals according to genetic type and sex. Seventeen CS and 16 LWxCS pigs were reared outdoor on woodland pastures (Quercus ilex, Castanea sativa) with minimum commercial mixtures supplementation. Both males and females were castrated. Since the age of 100 days morphological measures were recorded bimonthly (height at rump, body length, chest girth, width at shoulder, width at rump). To perform a statistical analysis, factors such as regression on age and allometric relationship on weight were taken into consideration, together with the fixed effect of genetic type x rearing system. In the indoor system, CS pigs reached 140 kg of live weight 30 and 100 days later than LWxCS and LW pigs, respectively. Moreover, CS conversion index was worse than that of LW pigs (i.e. 4.54 vs. 3.77 feed/gain) and CS backfat thickness was higher. During spring and summer, the outdoor system worsened the growth of backfat in both genetic types, as a consequence of scarce feed availability. However, cross pigs showed higher growth rate than CS breed. Allometric relationships analysis pointed out that CS pigs were taller, narrower at shoulder and at rump and shorter than LW pigs. Moreover, CS breed had higher chest girth than LW and the difference became more evident at higher weights. Crossbred pigs showed intermediate behaviour compared to parental breeds. Outdoor reared Cinta Senese pigs differed from those indoor in the evolution of body proportion, due to older age at a given weight and to the grazing activity. No differences were found with respect to for width values at rump, but outdoor CS pigs presented higher growth for width at shoulder and for chest girth. Thus, the outdoor system seems to intensify the development of the body forepart in Cinta Senese breed, already emphasised in this breed.

Application of multivariate analysis to sensorial and instrumental parameters of freshness in refrigerated sea bass (Dicentrarchus labrax) during shelf life

Abstract Freshness by sensory analysis descriptors and instrumental parameters (rigor index (RI), dielectric properties, K1, compactness (IC) and resilience (IEL), pH, free water (FW), cooking losses (CL)) was evaluated in sea bass stored at 4 and 1 °C with ice covering. Sensory scores presented high values of repeatability (≥0.70). The Principal Component Analysis of sensorial parameters revealed that Factor 1, accounting for a 95% of the variation and linked to storage duration, displayed homogenous behaviour. An antithesis between descriptors of external characteristics of fish and those relative to internal parts was observed, particularly in the intermediate phase of the shelf life, during which storage temperature played a discriminating role. The PCA of the sensorial and instrumental parameters together showed that the parameters most correlated with the first factor (83% of overall variance) were the sensorial ones (loading scores >0.96), K1 freshness index, rigor index and dielectric properties (loading scores =−0.96, 0.73 and 0.71, respectively). Data suggest that the external characteristics of the fish alone could be used to measure freshness. The K1, rigor index and dielectrics properties could be used as objective measures of freshness. Sensory ratings are less powerful for freshness analysis at the later stages of shelf life.

Application of two models to the lactation curve of Massese ewes

Abstract The experiment was carried out on 52 lactations of 37 multiparous Massese ewes. Milk yield was recorded weekly, starting before the 15th day from lambing. Due to the mating practice of the breed, three types of lactation were detected: Type 1, a short lactation initiated in autumn; Type 2, a short lactation initiated in spring, following the Type 1 lactation; Type 3, a long lactation initiated in autumn. The Wood model (W) and a bi-exponential function (CB) were applied to fit milk yield data of individual lactations. Milk yield of the whole lactation was estimated both by integrating the W and CB functions, and by using the Fleischmann official method. The W model, after the restriction of b >0, fitted the original data better than the CB model, particularly in late lactation. However, the CB model was more adequate for describing the initial sudden rapid increase of milk yield. Differences among the three methods for the estimate of total milk yield were very small, even though the CB model slightly overestimated late lactation. Among the three types of lactations, Type 2 had a much earlier peak, a higher peak yield and a lower persistency than the other two types. The ewes age at lambing influenced only the total milk yield, which reached the maximum at about 4 years of age.

Genetic variability in three Italian beef cattle breeds derived from pedigree information

Abstract The aim of the present work was to estimate genetic variability in Chianina (CH), Marchigiana (MC) and Romagnola (RO) breeds using pedigree information. Different approaches based on probability of identity-by-descent (effective population size through an increase in inbreeding Ne) or probability of gene origin (total number of founders f, effective number of founders fe, ancestors fa and founder genomes fg) were used. Reference populations were defined using female animals born between 1996 and 2000 where both parents are known. Generation intervals were 5.35, 4.93 and 5.15 years for CH, MC and RO, respectively. The total number of founders were 7092, 11947, 3928, for CH, MC and RO, respectively. Complete generation equivalent showed the relative high quality of pedigree information: 5.66 for CH, 4.54 for MC and 4.95 for RO. For CH, MC and RO, respectively, a fe value of 152.1, 70.9 and 89.8, a fa value of 73.6, 48.0 and 59.5 and a fg value of 39.5, 25.0 and 38.5, were calculated. When inbreeding was used effective population sizes were 138, 122 and 124 for CH, MC and RO, respectively. Parameters derived from the probabilities of gene origin were variable among the investigated breeds and the results for MC demonstrate the need to pay specific attention to breeding strategies.