"With the aim to assess the relationships between polymorphism at the calcium-sensitive casein. genes and yield, composition and renneting parameters of caprine milk, 200 Sarda goats,. genotyped at the CSN1S1, CSN2 and CSN1S2 genes, were utilised. Milk samples were. collected and daily milk yield was recorded at monthly intervals to determine: fat, protein, pH. (IDF 141C:2000) and coagulation properties (Formagraph instrument). Data were submitted to. a repeated-measures three-way GLM procedure; in the model CSN1S1, CSN2 and CSN1S2. were the random effects and only genotypes with frequencies higher than 4.0% were included.. The following genotypes were considered: at the CSN1S1 locus AA, AB, AF, BB, BF and FF;. at CSN2 AA, AC, CC and C01; at CSN1S2 AA, AC, AF, CC, CF and FF. Milk yield, which. varied in a range of 1,135 to 790 g\/d, was influenced by the effects of CSN1S1 (AA and BB >. BF and FF) and CSN1S2 (AC and CF > FF). As regards milk composition, the CSN1S1. genotype affected milk fat (AB > BB > BF and FF), protein (AB > BF > AF) and pH (AF and. FF > BB). The CSN2 genotype showed significant differences in protein (AA > AC > CC >. C01) and pH (AC > CC). At the CSN1S2 locus, significant differences occurred only for fat. (AC and CC > AA and CF). Fat and protein varied between 3.67 and 4.21 g\/100 mL and. between 4.60 and 5.03 g\/100 mL, respectively; the pH value varied between 6.67 and 6.71.. Clotting time (r) was affected only by CSN2, showing shorter mean times for AC and CC. (12.88 and 13.04 min) than AA (14.47 min). Curd firming time (k20) and curd firmness (a30). were influenced by all the three genes and varied between 1.90 and 2.74 min and between 47.4. and 35.2 mm, respectively. The CSN1S1 AB genotype displayed the lowest values of k20 and. the highest of a30, the FF genotype was opposite. The CSN2 C01, CC and AC genotypes. displayed decreasing values of k20, while CSN2 AC had the highest values of a30. The. CSN1S2 locus showed the highest values of k20 in the AA genotype and of a30 in AC and CC.. In conclusion, this study demonstrated the relationships between calcium-sensitive casein genes. and milk traits and provided useful information in order to improve genetic selection and. differentiation of productions."
Effect of calcium sensitive casein genotype on milk yield, composition and renneting properties of Sarda goat / Pazzola, Michele; Dettori, Maria Luisa; Balia, F.; Pira, Emanuela; Noce, A.; Carcangiu, Vincenzo; Vacca, Giuseppe Massimo. - (2012), pp. 77-77.
Effect of calcium sensitive casein genotype on milk yield, composition and renneting properties of Sarda goat.
PAZZOLA, Michele;DETTORI, Maria Luisa;PIRA, Emanuela;CARCANGIU, Vincenzo;VACCA, Giuseppe Massimo
2012-01-01
Abstract
"With the aim to assess the relationships between polymorphism at the calcium-sensitive casein. genes and yield, composition and renneting parameters of caprine milk, 200 Sarda goats,. genotyped at the CSN1S1, CSN2 and CSN1S2 genes, were utilised. Milk samples were. collected and daily milk yield was recorded at monthly intervals to determine: fat, protein, pH. (IDF 141C:2000) and coagulation properties (Formagraph instrument). Data were submitted to. a repeated-measures three-way GLM procedure; in the model CSN1S1, CSN2 and CSN1S2. were the random effects and only genotypes with frequencies higher than 4.0% were included.. The following genotypes were considered: at the CSN1S1 locus AA, AB, AF, BB, BF and FF;. at CSN2 AA, AC, CC and C01; at CSN1S2 AA, AC, AF, CC, CF and FF. Milk yield, which. varied in a range of 1,135 to 790 g\/d, was influenced by the effects of CSN1S1 (AA and BB >. BF and FF) and CSN1S2 (AC and CF > FF). As regards milk composition, the CSN1S1. genotype affected milk fat (AB > BB > BF and FF), protein (AB > BF > AF) and pH (AF and. FF > BB). The CSN2 genotype showed significant differences in protein (AA > AC > CC >. C01) and pH (AC > CC). At the CSN1S2 locus, significant differences occurred only for fat. (AC and CC > AA and CF). Fat and protein varied between 3.67 and 4.21 g\/100 mL and. between 4.60 and 5.03 g\/100 mL, respectively; the pH value varied between 6.67 and 6.71.. Clotting time (r) was affected only by CSN2, showing shorter mean times for AC and CC. (12.88 and 13.04 min) than AA (14.47 min). Curd firming time (k20) and curd firmness (a30). were influenced by all the three genes and varied between 1.90 and 2.74 min and between 47.4. and 35.2 mm, respectively. The CSN1S1 AB genotype displayed the lowest values of k20 and. the highest of a30, the FF genotype was opposite. The CSN2 C01, CC and AC genotypes. displayed decreasing values of k20, while CSN2 AC had the highest values of a30. The. CSN1S2 locus showed the highest values of k20 in the AA genotype and of a30 in AC and CC.. In conclusion, this study demonstrated the relationships between calcium-sensitive casein genes. and milk traits and provided useful information in order to improve genetic selection and. differentiation of productions."I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
