Abstract

Abstract. The experiment was performed on 121 primiparous Polish Holstein-Friesian (PHF) cows and 36 primiparous Jersey (JER) cows. The highest decrease in casein yield was noted in JER cows at 7.36 % on day 90 of lactation, 15.95 % on day 150, 26.78 % on day 210, 37.01 % on day 270 and 39.67 % on day 330. In PHF cows this decrease was substantially lower, at 4.98 %, 7.65 %, 8.72 %, 10.50 % and 16.19 % respectively. The casein content of milk from primiparous PHF cows ranged from 2.38 % (LGB – day 60) to 3.09 % (LGB BB – day 330), and it was found to be considerably lower in JER cows, varying between 2.35 % (CSN3 BB – day 30) and 3.61 % (CSN3 BB – day 210). The highest casein yield was recorded in PHF cows with the following genotypes: LGB AA (day 60), CSN1S1 BB (day 60), CSN2 AB (day 270), CSN3 BB (day 150). In JER cows the highest casein yield was noted on day 90 of lactation with respect to the following genotypes: LGB BB, CSN1S1 BC, CSN2 AA and CSN3 BB. In PHF cows the greatest effect on whey protein yield was exerted by the following genotypes: LGB AA (day 90), CSN1S1 BC (day 60), CSN2 AA (day 90); the CSN3 BB genotype influenced whey protein yield in cattle of both breeds (day 90). In JER cows the highest daily yield of whey proteins was observed on day 90 of lactation, with regard to the following genotypes: LGB BB, CSN1S1 BC, CSN2 AB and CSN3 BB.

Highlights

  • It was demonstrated that two whey proteins, α-lactalbumin (LALBA) and β-lactoglobulin (LGB), and four casein fractions, αs1 (CSN1S1), αs2 (CSN1S2), β (CSN2) and κ (CSN3) exhibit polymorphism

  • As regards the whey protein LGB, a higher milk yield is generally associated with the LGB AA genotype (OJALA et al, 1997; KAMIŃSKI et al, 2002), while a higher percentage content of fat and casein proteins – with the LGB BB genotype (WALAWSKI et al, 1994; LITWIŃCZUK et al, 1998)

  • In Polish Holstein-Friesian (PHF) cows the highest average yield of milk and milk components was noted in the second month of lactation, which was confirmed by statistically significant differences (p≤0.01 and p≤0.05) between the mean values of the analyzed traits

Read more

Summary

Introduction

It was demonstrated that two whey proteins, α-lactalbumin (LALBA) and β-lactoglobulin (LGB), and four casein fractions, αs (CSN1S1), αs (CSN1S2), β (CSN2) and κ (CSN3) exhibit polymorphism. The selection of Black-and-White cattle oriented towards a higher milk yield results in an increased frequency of the CSN3 A allele and a decreased frequency of the B allele (KAMIŃSKI et al, 2002; CZERNIAWSKA-PIĄTKOWSKA et al, 2004). In Jersey cattle populations the frequency of the CSN1S1 B genotype is much higher, and milk has a high content of protein and fat (ALEANDRI et al, 1990; JANN et al, 2002). The objective of this study was to characterize the yield and composition of milk as dependent on polymorphic milk protein variants, as well as to determine the yield and content of casein and whey proteins in milk in particular months of lactation of primiparous Polish HolsteinFriesian and Jersey cows

Objectives
Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call