Temporal changes of conjugated linoleic acid in milk from Sarda ewes with different milk fat secretion ability

Individual milk samples were weekly collected from 48 ewes during eight weeks. Ewes were at the second month of lactation and they were fed the same dietary regimen. The animals were grouped according to the amount of daily milk fat yield: A) 38-57g/d, B) 58-63g/d, C) 64-73g/d, D) 75-110g/d. Milk from group D showed a higher content of FA from C4 to C10 and a lower content of monounsaturated FA (MUFA) and conjugated linoleic acids (CLA) than Group A (+12%, -11%, and -18%, for C4 to C10, MUFA and CLA, respectively), while Group B and C showed intermediate values. CLA content increased with days of lactation in a similar way for all groups. The mean correlation among all records within each individual lactation was 0.45 for CLA content. Six milk FA pair ratios representing a proxy for SCD activity were also evaluated: group A showed higher values of FA ratios than Group D (+26% on average for all FA pairs). In conclusion, increasing ability of daily milk fat yield was associated with lower milk content of MUFA and CLA and higher content of FA from C4 to C10

Aspects of the animal food nutritional and nutraceutical value

The subject of this paper deals in the description of Italian zootechny with regard to animal food production and their quality. The last is well documented by the presence of a large number of certificated origin marks (53 POD e 11 PGI). Firstly, nutritional quality of food has been described, with particular emphasis for Glucides, Proteins, Lipids, Vitamins and Mineral elements contents and their metabolic role, in the most important food of animal origin: milk, meat, fish and eggs. After, the presence of nutraceutical substances in the same foods has been discussed. In particular the attention has been focused on the metabolic role of ω-3 fatty acids (EPA and DHA) and Rumenic Acid (C 18:2 cis 9 trans 11), the most important isomer of conjugated linoleic acid (CLA). In conclusion has been underlined the importance of nutraceutical substances of animal origin in human balanced diet. Furthermore the fundamental role of Italian zootechny to assure animal food safety and quality has been confirmed

Study on the influence of pasture on volatile fraction of ewes' dairy products by solid-phase microextraction and gas chromatography-mass spectrometry.

The detection of markers of identification of the geographical origin of food is an attractive challenge and, as far as dairy products are concerned, this paper represents a contribution to this field. In this research the influence of feed on the volatile compound composition was investigated on milk, 2-mo-old cheese (Caciotta), and whey cheese (ricotta) obtained from the same flock of Sarda ewes, under standardized technological conditions. Three different types of pasture (mixture of Lolium perenne and Trifolium squarrosum; rough pasture; Avena sativa) were studied. Solid-phase microextraction combined with gas chromatography-mass spectrometry was used and principal component analysis was applied for statistical evaluation of the data set. The volatile composition was significantly affected by the type of pasture independently of the type of cheese and the ripening period. Moreover, a marker of rough pasture, tentatively identified as (E,E)-3,7,11-tri-methyl-2,4,10-dodecatriene, was detected only in milk and cheeses produced when the ewe flock grazed on that pasture

Genetic and physiology basis of the quality of livestock products.

The animal research gives more attention, for more than twenty years, to the improvement of food quality, because this aspect plays an important role in the consumer choice. In this paper are browsed the principal foods of animal origin (milk, meat and eggs), paying attention on the actual genetic and physiologic knowledge, which influence the quality characteristic. Particularly, we examined the role of Quantitative Genetic in bovine and swine and the growing knowledge about animal genomes and individuation of QTL. Information on genomic regions that control QTL, allow to organize genetic improvement programs, using Markers Assisted Selection (MAS) and Markers Assisted Introgression (MAI). Moreover are reported the knowledge about metabolic processes that influence quality especially on lipid and protein component. About other productions are considered the physiology of eggs production and the genetic improvement of hens. Finally the qualitative aspects about poultry and rabbit meat and the actual genetic improvement strategy are reported

Monitoring of fatty acids composition of intraperitoneal, subcutaneus and intramuscular fat in commercial hybrids of sturgeons (Acipenser baeri x Acipenser tarsmontanus) during storage at 4°C

The composition of fatty acids (FA) in sturgeon, was studied during cold storage at 4 degreesC. Three different categories of lipid tissues (intramuscular, subcutaneous and intraperitoneal), were sampled at 0, 3 and 5 days of cold storage. The results showed a good level of preservation of the polyunsaturated fatty acid (PUFA) during the first 3 days of storage. Significant differences (p:5:0,05) were found between means at 0 and 5 days: at the day 0 PUFA in intramuscular, in subcutaneous and in intraperitoneal lipid tissues were respectively 18.86, 21.52 and 17.23 g/100 g of lipid extract, while at day 5 after death there were 12.34, 11.86 and 10.01 g/100 g of lipid extract, respectively. Results showed a strong decrease of FA content of the three lipid tissues sampled during the five days of cold storage and the main FA classes showed a similar trend of variation