Effect of beta-lactoglobulin polymorphism and seasonality on bovine milk composition

Abstract

The objective was to evaluate the effect of b-lactoglobulin (b-lg) polymorphism and seasonality on milk composition (fat, lactose, total solids, milk urea nitrogen, total protein, true protein, casein and somatic cell counts) of Holstein and Girolando cows. Milk and blood samples from 278 Holsteins cows and 156 Girolando cows were taken during two dry seasons and two rainy seasons, for milk composition analysis and to determine b-lg genotypes, respectively. BB genotype was the most frequent for both breeds, followed by AA genotype for Holstein (BB> AA> AB) and by AB for Girolando cows (BB> AB> AA). No differences were found in milk compositional characteristics among genetic variants of b-lg (AA, AB and BB) either between Holstein or Girolando cows. No association between milk composition and b-lg genetic polymorphism was observed. During the dry season, independently of the breed considered, higher contents of lactose, true protein, casein and casein : true protein ratio were found.

Quality based payment program and milk quality in dairy cooperatives of Southern Brazil: an econometric analysis

“…Farmer's average daily volume delivered did not contribute significantly to milk quality attributes, in contrast to information previously shown by other studies (Nightingale et al, 2008). The BTSCC pattern observed (specifically the peak in rainy seasons and the reduction in dry ones - Figure 1) was expected and followed the same trends as described in previous reports on similar climate conditions (Botaro et al, 2008).…”

Nucleotide sequencing and DNA polymorphism studies of beta-lactoglobulin gene in native Saudi goat breeds in relation to milk yield

“…The distribution of genotypic and allelic frequencies is presented in Table 4. The frequency of A allele was found to be lower compared to that of the B allele in all the Preliminary data has been presented in goats regarding β-LG genotypic variants and associated disparities in milk production traits (Kumar et al 2006;El-Hanafy et al 2010), though, no conclusive evidence is available regarding similar affects in sheep and cattle (Botaro et al 2008;Kawecka and Radko 2011). As obvious from Table 4, Habsi breed with the highest presence of A allele showed significantly higher milk yield (138.26 ± 1.26 l) than Ardi (132.11 ± 1.08 l) and Habsi (131.32 ± 1.08 l) breeds (P < 0.05).…”

Distinction of different heat-treated bovine milks by native-PAGE fingerprinting of their whey proteins

“…3). A genotype of b-LG has been shown to have a significant effect on milk protein composition and quality in several studies (Botaro et al, 2008;Cardak, Bartenschlager, & Geldermann, 2003). From this point of view, native-PAGE would be a meaningful method in the field of cow breeding with its advantage of simple operation and lower cost.…”