Caroli, A.

Cecchi, F.

Chessa, S.

Chiatti, F.

Martini, M.

Salari, F.

Scolozzi, C.

English

Institutional Research Information System University of Turin

ITAL.J.ANIM.SCI. VOL. 6 (SUPPL. 1), 2007 449The influence of β-lactoglobulin geneticpolymorphism on morphometriccharacteristics of milk fat globules andmilk fatty acids composition in ItalianFriesian cowM. Martini1, F. Cecchi1, C. Scolozzi1, F. Salari1, F. Chiatti2,S. Chessa2, A. Caroli31 Dipartimento di Produzioni Animali. Università di Pisa, Italy2 Dipartimento di Scienze e Tecnologie Veterinarie per la Sicurezza Alimentare.Università di Milano, Italy3 Dipartimento di Scienze Biomediche e Biotecnologie. Università di Brescia, ItalyCorresponding author: Mina Martini. Dipartimento di Produzioni Animali. Facoltà di Medicina veterinar-ia, Università di Pisa. Viale Piagge 2, Pisa, Italy - Tel. +39 050 2216897 - Fax: +39 050 2216901 - Email:mmartini@vet.unipi.itABSTRACTβ-lactoglobulin (β-Lg) is the major whey protein in the milk of ruminants and some non-ruminants. It was first iso-lated 60 years ago and a wealth of physico-chemical and biological information has been accumulated. Results ofstudies on the effect of β-Lg genotypes on milk production traits (milk yield, protein and fat yield) and on milkcoagulation parameters have been rather consistent. In this study we evaluated the relationship between geneticpolymorphism of β-Lg morphometric characteristics of fat globules and fatty acids composition of cow milk. Thetrial was carried out on 89 unrelated pluriparous Friesian dairy cows reared in the same herd in a medium-tem-perate climatic zone in the province of Pisa. All animals were fed the same diet. Individual milk samples were col-lected and analyzed in a triplicate. One milk sample of milk was collected for each cow and no preservative wasused. Genotypes were determined by isoelectric focusing analysis of single milk sample. Milk fatty acids composi-tion and morphometric characteristics of fat globules were analysed on each milk sample in triplicate. The fre-quency distribution of total measured milk fat globules was evaluated according to their size. Fat globule diame-ters were divided into nine classes of 1.5 µm width: from class 1 (1.5-3 µm) to class 9 (>13.5 µm). Finally, fat glob-ules were further classified into two groups: group S (1.5-6 µm), and group L (>6 µm). The analysis of variance wascarried out to evaluate the effect of β-Lg genotype on all evaluated parameters with simultaneous adjustment forsampling season, parity, and days from calving as a covariate. As reported in literature, a higher gene frequency ofthe B variant of β-Lg was observed (0.59 vs 0.41). Significant effects of β-Lg genotype were observed for the per-centage of the number of fat globules in the 8th (12-13.5 µm) and 9th class (>13.5 µm) which were higher in the ABgenotype than in the other genotypes. The C20:4ω6 content was significantly higher in the AB genotype (P<0.05)and C15:1 content was significantly higher in the AA genotype (P<0.05) than in the other genotypes. Although β-Lg genotypes would seem to have limited relationships with the dimensions of fat globules of cows’ milk, the high-er content of C20:4ω6 in AB genotype is of particular interest from the nutritional point of view.

The influence of β-lactoglobulin genetic polymorphism on morphometric characteristics of milk fat globules and milk fatty acids composition in Italian Friesian cow

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The influence of &#946;-lactoglobulin genetic polymorphism on morphometric characteristics of milk fat globules and milk fatty acids composition in Italian Friesian cow

The influence of β-lactoglobulin genetic polymorphism on morphometric characteristics of milk fat globules and milk fatty acids composition in Italian Friesian cow

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Institutional Research Information System University of Turin

The influence of &#946;-lactoglobulin genetic polymorphism on morphometric characteristics of milk fat globules and milk fatty acids composition in Italian Friesian cow

Abstract

Similar works

Full text

Available Versions

Institutional Research Information System University of Turin

The influence of β-lactoglobulin genetic polymorphism on morphometric characteristics of milk fat globules and milk fatty acids composition in Italian Friesian cow