title: Influence of race and crossbreeding on casein micelles size.
abstract: Casein (CN) micelles are colloidal aggregates of protein dispersed in milk, the importance of which in the dairy industry is related to functionality and yield in dairy products. The objective of this work was to investigate the correlation of milk CN micelles diameter from Holstein and Zebu crossbreds with milk composition (protein, fat, lactose, total and nonfat solids and milk urea nitrogen), somatic cell count (SCC), age, lactation stage and production. Average casein micelles diameters of milk samples obtained from 200 cows were measured using photon correlation spectroscopy and multiple regression analysis was used to find relationship between variables. CN micelle diameter, SCC and nonfat solids were different between animals with different Holstein crossbreed ratios, which suggests influence of genetic factors, mammary gland health and milk composition. Overall, results indicate the potential use of CN micelle diameter as a tool to select animals to produce milk more suitable to cheese production.
authors.affiliation: Department of Veterinary Preventive Medicine, Federal University of Minas Gerais, Brazil, Belo Horizonte, Brazil.
authors.forename: Denise R
authors.initials: DR
authors.lastname: Freitas
authors.forename: Leorges M
authors.initials: LM
authors.lastname: Fonseca
authors.forename: Fernando N
authors.initials: FN
authors.lastname: Souza
authors.forename: Cristiane V G
authors.initials: CV
authors.lastname: Ladeira
authors.forename: Soraia A
authors.initials: SA
authors.lastname: Diniz
authors.forename: João Paulo A
authors.initials: JP
authors.lastname: Haddad
authors.forename: Diêgo S
authors.initials: DS
authors.lastname: Ferreira
authors.forename: Marcelo M
authors.initials: MM
authors.lastname: Santoro
authors.forename: Mônica M O P
authors.initials: MM
authors.lastname: Cerqueira
mesh_terms: D000818:Animals; D002364:Caseins; D002417:Cattle / Q000235:genetics* / Q000502:physiology*; D002611:Cheese; D005260:Female; D006824:Hybridization, Genetic / Q000502:physiology*; D007774:Lactation / Q000502:physiology; D008823:Micelles; D008892:Milk / Q000737:chemistry* / Q000166:cytology; D008894:Milk Proteins / Q000032:analysis; D010316:Particle Size; D012044:Regression Analysis; D013057:Spectrum Analysis
chemical_list: D002364:Caseins; D008823:Micelles; D008894:Milk Proteins
keywords: milk urea nitrogen; nonfat solids; protein; somatic cell count