title: Variability of the caprine whey protein genes and their association with milk yield, composition and renneting properties in the Sarda breed: 2. The BLG gene.
abstract: The variability of the promoter region and the 3'UTR (exon-7) of the BLG gene, encoding the β-lactoglobulin, was investigated by sequencing in 263 lactating Sarda goats in order to assess its association with milk traits. Milk traits included: milk yield, fat, total protein and lactose content, pH, daily fat and protein yield (DFPY), freezing point, milk energy, somatic cell count, total microbial mesophilic count, rennet coagulation time (RCT), curd firming rate (k20) and curd firmness (a30). A total of 7 polymorphic sites were detected and the sequence analysed was given accession number KM817769. Only three SNPs (c.-381C>T, c.-323C>T and c.*420C>A) had minor allele frequency higher than 0.05. The effects of farm, stage of lactation and the interaction farm × stage of lactation significantly influenced all the milk traits (P T and c.*420C>A (P T (P < 0.001). The c.-381TT homozygous goats showed lower pH, RCT and k20 than c.-381CT (P < 0.05). In conclusion the polymorphism of the goat BLG gene did not affect the total protein content of the Sarda goat milk, and only weakly influenced RCT and k20. On the other hand, an interesting effect on milk yields and DFPY emerged in two SNPs. This information might be useful in dairy goat breeding programs.
authors.affiliation: Dipartimento di Medicina Veterinaria,Università degli Studi di Sassari,via Vienna 2,07100 Sassari,Italy.
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Dettori
authors.affiliation: Dipartimento di Medicina Veterinaria,Università degli Studi di Sassari,via Vienna 2,07100 Sassari,Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Pazzola
authors.affiliation: Dipartimento di Medicina Veterinaria,Università degli Studi di Sassari,via Vienna 2,07100 Sassari,Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Pira
authors.affiliation: Dipartimento di Medicina Veterinaria,Università degli Studi di Sassari,via Vienna 2,07100 Sassari,Italy.
authors.forename: Ornella
authors.initials: O
authors.lastname: Puggioni
authors.affiliation: Dipartimento di Medicina Veterinaria,Università degli Studi di Sassari,via Vienna 2,07100 Sassari,Italy.
authors.forename: Giuseppe Massimo
authors.initials: GM
authors.lastname: Vacca
mesh_terms: D000818:Animals; D002611:Cheese / Q000032:analysis; D005260:Female; D005838:Genotype; D006041:Goats / Q000235:genetics* / Q000502:physiology; D008892:Milk / Q000737:chemistry*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D013997:Time Factors; D000067816:Whey Proteins / Q000235:genetics*
chemical_list: D000067816:Whey Proteins
keywords: Goat milk; Sarda goat breed; beta lactoglobulin gene; goat BLG gene; renneting properties