Luisa Antonella Volpelli

Growth response of juvenile dentex (Dentex dentex L.) to varying protein level and protein to lipid ratio in practical diets

Abstract The dentex ( Dentex dentex L.) is a fast-growing sparid which represents a possible candidate for Mediterranean mariculture. As the basic nutrient requirements of this species are unknown, two feeding trials were carried out to identify suitable protein and lipid (energy) levels to be used in formulating practical diets for dentex. The experiments used groups of 30 specimens (each fish weighing 17 or 20.7 g) which were kept in 12 flow-through 160 1 tanks supplied with sea water at 2 1 min −1 (temperature 20 ± 1 °C; salinity 33 ppt). An initial 4-week trial was conducted to obtain a preliminary estimate of the optimal protein level. Triplicate groups were fed four practical diets with increasing levels of protein (44.3, 49.3, 55.7 and 58.9% dry matter (DM), over 90% of which was supplied by white fish meal) and a constant lipid content (17.3% DM; mostly supplied by fish lipids) to satiation. An analysis of the nutrient-weight gain relationship indicated that the optimal dietary protein level was 49.3% DM. In a second 60 day experiment, duplicate groups of fish were fed six diets with three protein levels (44.4, 49.5 and 55.8% DM) and two lipid contents (12.0 and 17.3% DM) within each protein level, nearly to satiation. Growth performance was lowest in fish given diets containing 44.4 or 49.5% protein and 12% lipid and was improved ( P −1 calculated available energy) could be assumed as suitable levels for formulating practical diets for this species, providing high quality fish meal and oil are used.

Carcass quality in male fallow deer (Dama dama): effects of age and supplementary feeding

Thirty-two male fallow deer, half 18- and half 30-month-old, were slaughtered after a 4-month feeding trial on pasture alone or with daily supplement of 500 g (dry matter) concentrate/head (eight each 18- and 30-month-old). The concentrate was composed of 40% maize, 25% sugar beet pulp, 20% alfalfa, 13% soy flakes, 2% minerals and vitamins. Supplemented deer were heavier (49.9 vs 45.0 kg) and their carcasses produced higher dressing proportions (61.5 vs 57.2%) and bigger amounts of first quality cuts. Supplemented feeding improved muscle development and fat deposition. Thirty-month-olds were heavier than 18-month-olds (53.3 vs 41.6 kg) and their carcasses produced higher dressing proportions (60.9 vs 57.7%) and bigger amounts of first quality cuts; older deer carcasses showed better conformation and bigger amounts of fat deposition.

Calpain system in vitro activity and myofibril fragmentation index in fallow deer (Dama dama): effects of age and supplementary feeding

Calpain system (μ- and m-calpain, calpastatin) and myofibril fragmentation index (MFI) were analysed on muscle longissimus thoracis et lumborum of 16 male fallow deer, half 18- and half 30-month-old, slaughtered after a 4-month feeding trial on pasture alone or with concentrate supplement. Diet did not produce any difference on the measured variables. The muscle of the elder deer had a higher calpastatin level 6 h post-mortem (136.0 vs. 99.7 units/50 g, for the 30- and 18-months-old, respectively), and a lower MFI value, particularly 24 h post-mortem (71.1 vs. 89.1). This is in agreement with previous data showing tougher meat from 30-month-old animals.

Assessment of welfare in pigs

Abstract According to the definition given by Appleby (1996), animal welfare represents the state of well-being brought about by meeting the physical, environmental, nutritional, behavioural and social needs of the animal or groups of animals under the care, supervision or influence of people. Suitable husbandry techniques and disease control (in which man is directly involved) may satisfy an animal’s physical, environmental and nutritive needs. However, it cannot be stated that people’s supervision or influence always guarantee the satisfaction of behavioural and social needs. Thus, special attention must be paid to these factors in intensive husbandry. This paper calls attention to the main factors characterizing pig welfare on the basis of productive, physiological, pathological and behavioural indicators; to the behavioural needs, which are characterised by several peculiar traits (it is noteworthy that, since the beginning, all categories of reared pigs have been involved in welfare legislation); to all categories of pigs that often show the effects of negative stimuli on their behaviour (limitations, variations); to the main critical points on the farm likely to cause welfare impairment or stress including buildings, inner facilities, space allowance, microclimate, lighting systems, environmental stressors, feeding management, mutilations, weaning, social factors, and stockmanship; and to environmental stressors including dust, odours (especially ammonia) and noises. This paper takes into account sources, effects and possible solutions for noises; the positive effect of fibrous feeding; environmental enrichment and other possible techniques for improving social status and for preventing/reducing stereotypic behaviour and abnormal reactions (e.g. tail biting). The scientific/objective evaluation of welfare for intensively reared pigs may be carried out by means of direct observation of the animals themselves (animal-based or encompassing performance or output criteria), as well as through examinations of a structural nature (design or resource-based, or derived from engineering or input criteria). Preference should be given to the former since they are can be better adapted to the different pig categories and management systems. Design criteria, on the other hand, are easier to evaluate and they should integrate animal criteria. Thus, the most correct protocols for on-farm evaluation of pig welfare should involve both animal-based criteria and design criteria. Examples of both criteria are reported herein. In extensive farming which includes (although somewhat improperly) outdoor and organic farming, achieving a good level of welfare is one of the declared objectives. However, there are several causes of welfare impairment that can be successfully overcome only if highly professional workers are employed: unfavourable climate, parasitic diseases, intake of plants containing poisons or anti-nutritional factors, high piglet mortality.

Pea (Pisum sativum) in dairy cow diet: effect on milk production and quality

Abstract The use of alternative plant protein in place of soybean meal protein in diets for farmed animals aims to reduce the extra-EU soybean import and partially substitute GMO in the food chain. Among the possible alternatives, the heat-processed (flaked) pea appears interesting in dairy cow diets. Two consecutive experiments were carried out to test flaked peas as a partial substitute for soybean meal in the diet of Reggiana breed dairy cows producing milk for Parmigiano-Reggiano cheese-making. In both experiments a “Control” concentrate (8.3% soybean meal) was compared to a “Pea” concentrate (5% soybean meal and 15% flaked peas). Forages fed to animals included mixed grass hay and alfalfa hay in experiment 1, and hay (mixed grass and alfalfa) plus mixed grass in experiment 2. Milk yield and quality, and the characteristics of grab faecal samples, examined to get some empirical indicators of digestibility, were similar between feeding groups. Compositional changes (crude protein and solubility) in forages used as common base in the diets of both experiments had a slight effect on milk and plasma urea contents. There was a tendency for a higher milk urea content in the “Pea” group (32.3 vs 30.1mg/dl in experiment 1, P<0.1; 30.2 vs 28.0mg/dl in experiment 2, P<0.1). The plasma urea content was different only in experiment 2 (4.9 vs 5.6mmol/l, respectively for “Control” and “Pea” groups; P<0.05). The inclusion of the heat-processed pea within the allowed limit of the Parmigiano-Reggiano Consortium for diet formulation could represent a feasible opportunity for a partial substitution of soybean meal.

Faba beans (Vicia faba) in dairy cow diet: effect on milk production and quality

The use of alternative plant proteins in place of the soybean meal protein in diets for farmed animals aims to reduce the extra-EU soybean import and partially substitute the GMO in the food chain. Among the possible alternatives, the heat-processed (flaked) faba beans appears interesting for dairy cow diet. Two consecutive experiments were carried out to test flaked faba beans as a partial substitute for soybean meal in the diet of Reggiana breed dairy cows producing milk for Parmigiano-Reggiano cheese-making. In both experiments a “Control” concentrate (12% soybean meal, no faba beans) was compared with a “Faba” concentrate (7.5% soybean meal and 10% flaked faba beans). Forages fed to animals were hay (mixed grass and alfalfa) plus mixed grass in experiment 1, hay only in experiment 2. Milk yield and quality and the characteristics of grab faecal samples as empirical indicators of digestibility, were similar between feeding groups. The milk urea content was slightly lower in the “Faba” group, particularly in experiment 2 (“Control” vs “Faba”: 34.6 vs 32.9 mg/dL in experiment 1, P<0.1; 27.4 vs 23.4 mg/dL in experiment 2, P<0.01); the plasma urea content in experiment 2 confirmed the trend observed in milk (3.9 vs 3.0 mmol/L, P<0.01). The inclusion of faba beans, within the allowed limit of the Parmigiano-Reggiano Consortium for diet formulation, could represent a feasible opportunity for a partial substitution of soybean meal.

Evaluation of mast cells in calf and heifer uteri

Little is known about the characteristics of mast cells present in the wall of the bovine uterus. The aims of the present study were to determine the main distribution patterns of mast cells residing in the uterine walls of calves and heifers and to obtain reference values for these cells in order to assist in the evaluation of endometrial biopsies in cows. A total of 59 young Italian Friesian cattle (30 prepubertal heifers 8 to 10 mo old and 29 post pubertal heifers 15 to 18 mo old that had not calved) were chosen on the basis of absence of lesions of the genital tract, following clinical examination for macroscopic and microscopic pathology. Only pubescent heifers which were in the diestral phase of their cycle were chosen. After slaughter, tissue samples were collected from the uterine body and each horn, and were then fixed in buffered formalin. Histological sections (5 μm), stained with Toluidine blue (0.003% at pH 4.9), were used for cell counts in 5 optical fields at x 400 magnification (0.18 mm2), randomized for each layer from both the wall of the body and each horn: stratum compactum (SC), st. spongiosum (SS), st. musculare (SM), st. vasculare (SV) and tunica serosa (TS). The number of mast cells in the layers for pre- and post-pubertal heifers were, respectively: SC 5.5 and 11.2; SS 2.8 and 2.7; SM 0.8 and 2.8; SV 3.0 and 4.6; and TS 1.4 and 3.9. The results indicated that the number of mast cells increased with age (calves 2.7 vs heifers 4.7; P < 0.001), particularly in heifers, that the values for the uterine body and horns were not different (4.5 and 4.8) and that SC and SV had the highest values in both groups. The reference values proposed for the resident mast cells are (mast cells/ x 400): 11 for SC alone, 7 as an average of SC+SS, and 5 as an average of SC+SS+SM+SV.

Preliminary investigation of the use of digital image analysis for raw ham evaluation

Abstract In order to find objective parameters for the evaluation of pig thighs to be used for PDO processing, digital images of the external surface of 384 left thighs were acquired, to be used for multivariate image analysis. The following parameters were also measured on the same samples: weight, length, circumference, thickness of fat and thigh, globosity index and colour of skin. Moreover, a subjective evaluation of veining and red skin defects was also made by an expert assessor. Multivariate analysis of the digital images showed a separation of the analysed samples in two clusters, whose differences were then investigated on the basis of the other traits. Various differences between the two clusters where found, mainly for the size-related parameters.

Effect of stunning voltage and scalding method on the incidence of the “red skin” defect of Parma ham

Effect of stunning voltage and scalding method on the incidence of the “red skin” defect of Parma ham D. P. Lo Fiego & M. Comellini & M. C. Ielo & F. Tassone & L. A. Volpelli # Springer Science + Business Media B.V. 2009

Effect of ageing time on consumer-perceived quality of Italian Simmental beef

Abstract The aim of the experiment was to provide an objective indication on the optimal ageing time of meat from Italian Simmental (IS) young bulls, the most important commercial category of the breed. The research was carried out on 10 young bulls slaughtered at the average weight of 688 kg (SE: 7.3 kg). The right side of each carcass was stored for 7 days and the left one for further 7 days, at normal refrigeration temperatures. At the end of the ageing period, the sides were sampled at the loin for meat pH, color, cooking loss and shear force measurement. A central location, affective test involving 74 consumers was carried out to measure the degree of liking for grilled beef aged 7 or 14 days. The pH and color parameters were not significantly affected by the duration of post-mortem storage, while cooking loss increased (31.4 vs 32.6 %; P<0.05) and shear force values diminished (56.7 vs 46.8 N; P< 0.01) when ageing time increased from 7 to 14 days. The degree of liking by the untrained respondents for the two types of cooked meat was different, considering that consumers gave the highest hedonistic scores to beef aged 14 days. Tenderness was the sensory attribute that allowed the best discrimination between beef stored for periods of different length. In fact, while the difference between 14-day-aged and 7-day-aged beef for flavour ratings (7.0 vs 6.9) did not reach the threshold of significance, the former meat was perceived as significantly finer than the latter regarding tenderness (6.5 vs 5.6; P= 0.01) and marginally preferred in overall terms (6.9 vs 6.5; P= 0.07). The classification test, carried out at the end of the quantitative test by asking consumers to select from a list the most appropriate attributes describing the stimuli associated with meat consumption, confirmed the effectiveness of texture attributes in ranking different-aged beef acceptability. In fact, the number of ticks reported for chewiness and juiciness descriptors were different for the two types of meat: the 14-day-aged beef was perceived as easier to chew (57 vs 34 ticks) and juicier (42 vs 24) than the shortest-aged beef. Ageing for 14 days should be recommended as a process control point for the beef industry to improve consumer acceptance of IS young bull beef.