The objective of this study was to analyze the genetic variability of milk proteins of the Carora, a short-horned Bos taurus cattle breed in Venezuela and in other Southern American countries that is primarily used for milk production. A total of 184 individual milk samples were collected from Carora cattle in 5 herds in Venezuela. The milk protein genes αs1-casein (CN) (CSN1S1), β-CN (CSN2), κ-CN (CSN3), and β-lactoglobulin (LGB) were typed at the protein level by isoelectrofocusing. It was necessary to further analyze CSNlSl at the DNA level by a PCR-based method to distinguish CSN1S1*G from B. Increased variation was found in particular at the CSN1S1 gene, where 4 variants were identified. The predominant variant was CSN1S1*B (frequency = 0.8). The second most common CSN1S1 variant was CSN1S1*G (0.101), followed by CSN1S1*C (0.082). Moreover, a new isoelectrofocusing pattern was identified, which may result from a novel CSN1S1 variant, named CSN1S1*I, migrating at an intermediate position between CSN1S1*B and CSN1S1*C. Six cows carried the variant at the heterozygous condition. For the other loci, predominance of CSN2*A 2 (0.764), CSN3*B (0.609), and LGB*B (0.592) was observed. Haplotype frequencies (AF) at the CSN1S1-CSN2-CSN3 complex were also estimated by taking association into account. Only 7 haplotypes showed AF values >0.05, accounting for a cumulative frequency of 0.944. The predominant haplotype was B-A2-B (frequency = 0.418), followed by B-A 2-A (0.213). The occurrence of the G variant is at a rather high frequency, which is of interest for selection within the Carora breed because of the negative association of this variant with the synthesis of the specific protein. From a cheese-making point of view, this variant is associated with improved milk-clotting parameters but is negatively associated with cheese ripening. Thus, milk protein typing should be routinely carried out in the breed, with particular emphasis on using a DNA test to detect the CSN1S*G variant. The CSN1S*G allele is likely to have descended from the Brown Swiss, which contributed to the Carora breed and also carries this allele.

Carora cattle shows high variability at αSl-casein / A. Caroli, S. Chessa, F. Chiatti, D. Rignanese, B. Meléndez, R.M. Rizzi, G. Ceriotti. - In: JOURNAL OF DAIRY SCIENCE. - ISSN 0022-0302. - 91:1(2008 Jan), pp. 354-359. [10.3168/jds.2007-0420]

Carora cattle shows high variability at αSl-casein

S. Chessa
Secondo
;
F. Chiatti;D. Rignanese;R.M. Rizzi
Penultimo
;
G. Ceriotti
Ultimo
2008-01

Abstract

The objective of this study was to analyze the genetic variability of milk proteins of the Carora, a short-horned Bos taurus cattle breed in Venezuela and in other Southern American countries that is primarily used for milk production. A total of 184 individual milk samples were collected from Carora cattle in 5 herds in Venezuela. The milk protein genes αs1-casein (CN) (CSN1S1), β-CN (CSN2), κ-CN (CSN3), and β-lactoglobulin (LGB) were typed at the protein level by isoelectrofocusing. It was necessary to further analyze CSNlSl at the DNA level by a PCR-based method to distinguish CSN1S1*G from B. Increased variation was found in particular at the CSN1S1 gene, where 4 variants were identified. The predominant variant was CSN1S1*B (frequency = 0.8). The second most common CSN1S1 variant was CSN1S1*G (0.101), followed by CSN1S1*C (0.082). Moreover, a new isoelectrofocusing pattern was identified, which may result from a novel CSN1S1 variant, named CSN1S1*I, migrating at an intermediate position between CSN1S1*B and CSN1S1*C. Six cows carried the variant at the heterozygous condition. For the other loci, predominance of CSN2*A 2 (0.764), CSN3*B (0.609), and LGB*B (0.592) was observed. Haplotype frequencies (AF) at the CSN1S1-CSN2-CSN3 complex were also estimated by taking association into account. Only 7 haplotypes showed AF values >0.05, accounting for a cumulative frequency of 0.944. The predominant haplotype was B-A2-B (frequency = 0.418), followed by B-A 2-A (0.213). The occurrence of the G variant is at a rather high frequency, which is of interest for selection within the Carora breed because of the negative association of this variant with the synthesis of the specific protein. From a cheese-making point of view, this variant is associated with improved milk-clotting parameters but is negatively associated with cheese ripening. Thus, milk protein typing should be routinely carried out in the breed, with particular emphasis on using a DNA test to detect the CSN1S*G variant. The CSN1S*G allele is likely to have descended from the Brown Swiss, which contributed to the Carora breed and also carries this allele.
αs1-casein; Carora cattle; Milk protein; Venezuela
Settore AGR/17 - Zootecnica Generale e Miglioramento Genetico
Settore AGR/19 - Zootecnica Speciale
Article (author)
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/55227
Citazioni
  • ???jsp.display-item.citation.pmc??? 3
  • Scopus 11
  • ???jsp.display-item.citation.isi??? 12
social impact