he aim of this study was to estimate heritability's of rennet coagulation time (RCT) and curd firmness (CF) and their genetic correlations with milk yield and composition. Three hundred Mediterranean buffalo cows were sampled in 6 herds located in Southern Italy. Milk coagulation properties of each buffalo cow were measured using a computerized renneting meter. The statistical analysis was performed using the SPSS (2003). No significant dependence was found between RCT and fat, density, protein content and pH. No significant dependence was found between CF and density, lactose, protein, and casein contents and pH. The coefficient of determination (R2) by RCT, that is the proportion of variability of a character explained by a model, has turned out to be equal to 88% for day of lactation, 0.1% for date of calving and 0% for parity, while the R2 of CF was found equal to 73%, 68% and 0% respectively for day of lactation, date of calving and parity. The estimated hereditability was found to be 0.27 ± 0.03 and 0.11 ± 0.001 for RCT and CF respectively. The genetic correlation between RCT and both day of lactation and date of calving was negative (-0.28 p<0.01 and -0.059 n.s., respectively). running head: Genetic parameter and milk coagulation ability. The genetic correlation was negative (-0.54 n.s.) between CF and day of lactation, and positive (0.35 n.s.) between CF and date of calving. The genetic correlation between RCT and milk yield were moderate for RCT and highly negative for CF. An interesting genetic significant relationship was detected between RCT and density, protein and casein content. Further studies are needed for standardized the results in all buffalo livestock managements system.
Milk coagulation ability an genetic parameter and their relationships with milk characteristics in buffalo cows
Sarubbi F;Auriemma G;Formisano G;Palomba R
2016
Abstract
he aim of this study was to estimate heritability's of rennet coagulation time (RCT) and curd firmness (CF) and their genetic correlations with milk yield and composition. Three hundred Mediterranean buffalo cows were sampled in 6 herds located in Southern Italy. Milk coagulation properties of each buffalo cow were measured using a computerized renneting meter. The statistical analysis was performed using the SPSS (2003). No significant dependence was found between RCT and fat, density, protein content and pH. No significant dependence was found between CF and density, lactose, protein, and casein contents and pH. The coefficient of determination (R2) by RCT, that is the proportion of variability of a character explained by a model, has turned out to be equal to 88% for day of lactation, 0.1% for date of calving and 0% for parity, while the R2 of CF was found equal to 73%, 68% and 0% respectively for day of lactation, date of calving and parity. The estimated hereditability was found to be 0.27 ± 0.03 and 0.11 ± 0.001 for RCT and CF respectively. The genetic correlation between RCT and both day of lactation and date of calving was negative (-0.28 p<0.01 and -0.059 n.s., respectively). running head: Genetic parameter and milk coagulation ability. The genetic correlation was negative (-0.54 n.s.) between CF and day of lactation, and positive (0.35 n.s.) between CF and date of calving. The genetic correlation between RCT and milk yield were moderate for RCT and highly negative for CF. An interesting genetic significant relationship was detected between RCT and density, protein and casein content. Further studies are needed for standardized the results in all buffalo livestock managements system.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
