The aim of this study was to estimate the repeatability of morphometric characteristics of counted milk fat globules number of globules/milliliter, average diameter, frequency distribution of globules according to different size analyzed in 3 different phases of lactation (10, 30 and 90 days from parity). Milk samples were taken from 25 Massese ewes homogeneous for age and diet; all the animals came from a single herd located in the province of Pisa (Tuscany). All individual samples were taken from the morning milking and were refrigerated until use, placed in a Burker chamber and observed by fluorescent microscope and image analyzer system. The repeatability of morphometric characteristics of milk fat globules tested in the three phases of lactation was estimated by Pearson's correlations (r) while the average repeatability has been tested across the method of intra-correlation-cl ass. Fat globules tend to change over the course of lactation, and as production progresses, favours an increase in the percentages of small and medium globules and a decreased percentage of the large globules. Only fat globules of 5-6 mu m (class 5, 15% of the total globules) and medium diameter show good repeatability during lactation (0.41 and 0.31 respectively).
The repeatability of morphometric characteristics of milk fat globules from Massese ewes during lactation
CECCHI, FRANCESCA;MARTINI, MINA;SALARI, FEDERICA
2005-01-01
Abstract
The aim of this study was to estimate the repeatability of morphometric characteristics of counted milk fat globules number of globules/milliliter, average diameter, frequency distribution of globules according to different size analyzed in 3 different phases of lactation (10, 30 and 90 days from parity). Milk samples were taken from 25 Massese ewes homogeneous for age and diet; all the animals came from a single herd located in the province of Pisa (Tuscany). All individual samples were taken from the morning milking and were refrigerated until use, placed in a Burker chamber and observed by fluorescent microscope and image analyzer system. The repeatability of morphometric characteristics of milk fat globules tested in the three phases of lactation was estimated by Pearson's correlations (r) while the average repeatability has been tested across the method of intra-correlation-cl ass. Fat globules tend to change over the course of lactation, and as production progresses, favours an increase in the percentages of small and medium globules and a decreased percentage of the large globules. Only fat globules of 5-6 mu m (class 5, 15% of the total globules) and medium diameter show good repeatability during lactation (0.41 and 0.31 respectively).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
