253 research outputs found
Alternative animal protein sources for aquaculture: a preliminary study on nutritional traits of Mediterranean brocade (Spodoptera littoralis, Boisduval) larvae
In formulating diets for farmed aquatic species, the main ingredi- ent used is fish meal (FM). Due to the growth that aquaculture is experiencing throughout the world, the increasing demand of feeds is resulting in a FM price increase that represents an eco- nomic limit for fish farming. The need to seek protein sources alternative to FM is a matter of great interest. Among others, the use of insect larvae as feed for fish represents an interesting alter- native. The aim of this study was to evaluate the nutritional traits of mediterranean brocade larvae (Spodoptera littoralis Bois.) in view of their possible use as feedstuffs for rainbow trout. A sample of mediterranean brocade larvae (MBL) (VI instar) and one of pupae (MBP) were assayed for fat (EE), ash (ASH) and crude pro- tein (CP) contents by conventional methods. Amino-acidic profile was obtained by HPLC on sample hydrolysates. Relative digestibil- ity of protein (RDP) was estimated by the Lazo (1988) method. Data, expressed on DM basis, were compared with those of a com- mercial feed (CF). The fat content of MBL was lower than that recorded for CF (9.4% vs 13.6%) while MBP showed a very high value (30.3% DM). Ashes in MBL (7.7%) and MBP (6.7%) were lower than in the CF (10.9%). The CP content of MBL (44.3%) was slightly higher than the CF (40.0%) but lower than in MBP (59.1%). The RDP of MBL and MBP were about a half of the value observed in CF (27.2%). Both MBL and MBP showed a lower per- centage of essential amino acids (AA) (35.8%, 36.8%) compared to CF (39.4%) even if the AA profiles were in line with the require- ments found in literature for rainbow trout. In conclusion, these preliminary results suggest that preimaginal stages of S. littoralis may be of interest in fish feeding, though more exhaustive studies have to be performed to fully assess their use as alternative for fish meal
Influence of dietary vitamin E supplementation on cholesterol oxidation and fresh colour in beef aged for 3 and 14 days
The effects of dietary vitamin E supplementation on the susceptibility to lipid oxidation and colour of the Longissimus thoracis (LT) muscle aged in vacuum packaged conditions for 3 or 14 days were studied. For this purpose, Charolais cattle were fed on a diet providing daily 60 mg (control) or 5500 mg of vitamin E per animal (supplemented) for 30 and 60 days before slaughter. Dietary vitamin E supplementation increased the liver vitamin E content, but not in the LT muscle of treated animals. The vitamin supplementation for 30 and 60 days has shown non-consistent effects in reducing cholesterol oxidation products of vacuum-packed aged meat. However, the vitamin E supplementation for 60 days was effective on Lightness stability in LT muscle during vacuum-packed ageing. Overall, from the practical standpoint, this study suggests that supranutritional supplementation up to 60 days may not increase the vitamin E content of Charolais LT muscle giving little, if any, benefits on meat colour and cholesterol oxidation. However, the present study suggests that it would be interesting to determine in which extent specific oxysterols are related to the meat colour and whether colour parameters can be useful for predicting the formation of cholesterol oxidation products along the industrial meat production chain.The effects of dietary vitamin E supplementation on the susceptibility to lipid oxidation and colour
of the Longissimus thoracis (LT) muscle aged in vacuum packaged conditions for 3 or 14 days
were studied. For this purpose, Charolais cattle were fed on a diet providing daily 60mg (control)
or 5500mg of vitamin E per animal (supplemented) for 30 and 60 days before slaughter. Dietary
vitamin E supplementation increased the liver vitamin E content, but not in the LT muscle of
treated animals. The vitamin supplementation for 30 and 60 days has shown non-consistent
effects in reducing cholesterol oxidation products of vacuum-packed aged meat. However, the
vitamin E supplementation for 60 days was effective on Lightness stability in LT muscle during
vacuum-packed ageing. Overall, from the practical standpoint, this study suggests that supranutritional
supplementation up to 60 days may not increase the vitamin E content of Charolais
LT muscle giving little, if any, benefits on meat colour and cholesterol oxidation. However, the
present study suggests that it would be interesting to determine in which extent specific oxysterols
are related to the meat colour and whether colour parameters can be useful for predicting
the formation of cholesterol oxidation products along the industrial meat production chain
Influence of short- and long-term exposure to a hot environment on rumen passage rate and diet digestibility by Friesian heifers.
Effects of short- and long-term exposure to a hot environment on diet digestibility and rumen passage rate were studied in four, 10-mo-old Friesian heifers housed in a climatic chamber. The trial lasted 65 d. Twenty-five days were spent under thermal comfort (temperature-humidity index = 64), and 40 d were spent under hot conditions (temperature-humidity index = 84). Three digestibility and rumen passage rate trials were performed during the 65 d. Chromium oxide was used as an external marker. The first digestibility and rumen passage rate trial (trial 1) was performed under thermal comfort; trials 2 and 3 were performed under hot conditions. Exposure to the hot environment reduced dry matter intake and increased water intake and rectal temperature compared with those during the thermal comfort period. Digestibility coefficients for dry matter, organic matter, neutral detergent fiber, and acid detergent fiber were higher in trial 2 than in trials 1 and 3. No statistical differences were found between trials 1 and 3 for these variables. Rumen passage rate was more rapid in trial 1 than in trials 2 and 3. No difference was observed between trials 2 and 3. These results indicated that exposure to a hot environment can affect digestibility in a time-dependent fashion, suggesting an adaptation of the digestive tract to hot environments
Concentrations of some toxic and trace elements in wild boar (<i>Sus scrofa</i>) organs and tissues in different areas of the Province of Viterbo, Central Italy
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Sfamare un mondo di nove miliardi di persone: le sfide per una zootecnia sostenibile
A dramatic increase of the demand for products of animal origin is expected to occur due to: i) the exponential growth of world's population, which should reach 9 billion people in 2050, according to FAO predictions, ii) the process of urbanization which will likely lead to a concentration of 60% of the population in urban areas by the same year, and iii) the increase of income of a large part of the population in emergent countries such as China and India. So far, the increased demand for food has been supplied by agriculture due to improvement of techniques, increase of cultivated land areas and increase of consumption of water and energy. Despite that, unequal food distribution throughout the world has lead to almost 1 billion undernourished or starving people at the first decade of the twenty-one century. In the future, it will be necessary to achieve a sustainable supply of food, especially of animal origin, because land and other production factors are not unlimited resources. This work deals with related problems and possible sustainable solutions for the increasing demand for products of animal origin, by a detailed analysis of the Animal footprint , i.e. the Ecological footprint of animal production
Heat shock induced changes of adipokines gene expression in 3T3-L1 adipocytes
To study the effects of heat shock on adipokines gene expression 3T3-L1 adipocytes were used.
Heat shock differently affected gene expression of leptin, adiponectin and acylation stimulating protein (ASP): exposure of cells to temperature higher than 39°C caused upregulation of leptin and downregulation of adiponectin and ASP genes. The present study provides the first evidence about the effects of heat shock on adipokines gene expression. Changes in gene expression of the three adipokines may help to explain the alteration of lipid metabolism
and liver functionality occurring in animals exposed to hot conditions
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