|Van Vleck, Lloyd|
Submitted to: Livestock Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/21/2001
Publication Date: N/A
Interpretive Summary: Mozzarella cheese is an important product of Italian river buffalo. This study of official milk records of river buffalo cows reports estimates of heritabilities of, and genetic correlations among, milk, fat, protein, and mozzarella yields and fat and protein percentages. Heritability estimates were .10 to .17 which are much less than for the same traits of dairy cattle. The small estimates may be due to a contraction in size of the population about 40 years ago or may be due to misidentification. Genetic correlations among yield traits including mozzarella yield were large. These estimates can be used for national genetic evaluations and can be used to design selection indexes to improve yield of mozzarella cheese.
Technical Abstract: The objective was to estimate genetic parameters for the Italian population of river buffaloes. Lactation records (10,663) for milk, fat, protein and mozzarella cheese production of river buffalo cows were analyzed by fitting a multiple trait animal model using restricted maximum likelihood. The number of cows with records was 3,873 with 6,842 animals in the relationship matrix. Fixed effects included in the model were: herd by year subclass, calendar month of calving, number of times milked per day, a cubic covariate for months of age at parity and a quadratic covariate for days in the previous dry period. Mozzarella cheese production per lactation was computed by considering milk yield, and fat and protein percentages. The average yields of milk, fat, protein and mozzarella (kg) and fat and protein percentages were 2,286.8 (492.1), 196.9 (45.6), 104.7 (21.7), 589.1 (125.4), 8.59 (.85), 4.55 (.28), respectively. Heritability estimates for milk, fat, protein and mozzarella yields and fat and protein percentages were 0.14, 0.11, 0.14, 0.13, 0.17 and 0.10, respectively. Although estimates of heritability are less than for the same traits of dairy cattle, estimates of phenotypic and genetic correlations among all traits show the possibility of developing a selection scheme to improve characteristics of milk for production of mozzarella cheese, the most important product of Italian buffaloes.